AIOH Simplified Occupational Hygiene Risk Management

Prévia do material em texto

AUSTRALIAN INSTITUTE OF 
OCCUPATIONAL HYGIENISTS INC
ARBN: 637 163 850 
Edited by
IAN FIRTH
 ROBERT GOLEC
ROSS DI CORLETO
 KIM NG 
 JAEMIE WILSON
SIMPLIFIED OCCUPATIONAL HYGIENE 
RISK MANAGEMENT STRATEGIES
AIOH Risk Management Guidebook Page 1 
 
Simplified Occupational Hygiene Risk 
Management Strategies 
 
An Australian Institute of Occupational Hygienists (AIOH) guidebook for occupational hygienists and 
other occupational health and safety (OHS) practitioners on how to identify, assess and control risks 
arising from workplace exposures 
 
 
 
Ian Firth, Robert Golec, Ross Di Corleto, Kim Ng & Jaemie Wilson 
 
Published by the 
Australian Institute of Occupational Hygienists Inc (AIOH) 
PO Box 2124 
Gladstone Park Victoria 3043 
Suite 11, 99 - 101 Western Avenue, Westmeadows 3049 
Tel: +61 3 9338 1635 
Email: admin@aioh.org.au 
AIOH Risk Management Guidebook Page 2 
 
Published by: the Australian Institute of Occupational Hygienists Inc 
PO Box 2124 
Gladstone Park Victoria 3043 
First published June 2006 
Second edition published June 2020 
© Australian Institute of Occupational Hygienists Inc. 
Printed copies of this document may be purchased directly from the Australian Institute of 
Occupational Hygienists Inc at the above address. Reference to the Australian Institute of 
Occupational Hygienists Inc is requested for any part of this document used in other material. 
National Library of Australia 
Cataloguing-in-Publication entry 
Firth, Ian, Golec, Robert, Di Corleto, Ross, Ng, Kim & Wilson, Jaemie 
Simplified Occupational Hygiene Risk Management Strategies 
An AIOH guidebook for occupational hygienists and other occupational health and safety (OHS) 
practitioners on how to identify, assess and control risks arising from workplace exposures. 
ISBN 978-0-9803010-4-5 
Printed by MinuteMan Press Tullamarine 
This document is written for purposes of clarity and directness in the second and third persons, and 
to the extent that it is possible when discussing technical matters, in plain English. 
 
AIOH Risk Management Guidebook Page 3 
 
PREFACE - WHAT IS THIS GUIDEBOOK ABOUT? 
 
Under the Australian system of government, the States and Territories have responsibility for 
making laws about workplace health and safety and for enforcing those laws. Each State and 
Territory has a principal occupational health and safety (OHS) Act and Regulations that set out 
requirements for ensuring that workplaces are safe and healthy, most being based on a model Work 
Health and Safety (WHS) Act and Regulations. These requirements, known as the duty of care, are 
for the protection of workers and other persons against harm to their health, safety and welfare 
through the elimination or minimisation of risks arising from work, so far as is reasonably 
practicable1. Other jurisdictions often have similar requirements. 
‘Reasonably practicable’ means that the requirements of the law vary with the degree of risk in a 
particular activity or environment which must be balanced against the time, trouble and cost of 
taking measures to control the risk. It allows the person conducting a business or undertaking 
(PCBU) to choose the most efficient means for controlling a particular risk from the range of feasible 
possibilities, preferably in accordance with the ‘hierarchy of control’. 
The ‘hierarchy of control’ refers to the range of feasible options for managing the risk to health and 
safety. The hierarchy normally ranges over the following controls: elimination of the hazard; its 
substitution with something less harmful; redesign; engineering controls; isolation of the hazard 
from people at the workplace; safe work practices; redesigning work systems; and the use of 
personal protective equipment by people at the workplace (in that order). 
Safe Work Australia (SWA) sets OHS Standards for hazards common to many industries and 
workplaces across Australia, which become law when adopted as regulations in each of the States 
and Territories. All of these Standards require employers to identify and manage risks arising from 
workplace exposures, consistent with the duty of care. Risk management is legislated in Australian 
regulations but risk assessment is not specifically mentioned, although it is part of the risk 
management process. The WHS Act also requires that designers must ensure, so far as is reasonably 
practicable, that plant, substances or structures are designed to be without risks to the health and 
safety of persons1. Ideally, the design of new plant, processes and work practices should aim to 
eliminate the hazard or reduce the risk of exposure. 
This guidebook provides occupational hygienists and other occupational health and safety (OHS) 
practitioners with some basic tools to conduct risk management for occupational health hazards 
such as biological, chemical, ergonomic (e.g. manual handling), radiation and other physical 
exposures (e.g. noise and vibration). It thus covers hazard identification, exposure characterisation 
and risk assessment, control and management. For the occupational hygienist, exposure assessment 
and risk assessment cannot be reasonably separated. For this reason, this guidebook is a companion 
guide with the ‘Occupational Hygiene Monitoring and Compliance Strategies’ (Grantham & Firth, 
2014) guidebook, also published by the Australian Institute of Occupational Hygienists (AIOH). 
 
1 Safe Work Australia ‘Model Work Health and Safety (WHS) Laws’ webpages. 
https://www.safeworkaustralia.gov.au/law-and-regulation/model-whs-laws (accessed 24/05/2019). 
https://www.safeworkaustralia.gov.au/law-and-regulation/model-whs-laws
AIOH Risk Management Guidebook Page 4 
 
While this guidebook specifies the elements of the risk management process, it does not suggest risk 
management systems for occupational health hazards should be uniform. It is generic and 
independent of any specific industry. The design and implementation of a risk management system 
will be influenced by the varying needs of an organisation, its particular objectives, its products and 
services, and the processes and specific practices employed. Where possible, health risk assessment 
should be integrated with that of safety, environment and other business risk assessment to best 
prioritise control actions. 
This guidebook is intended for use in the field of occupational hygiene to assist with the control of 
potential workplace hazards and for no other use. The consequence, likelihood and risk levels 
indicated are not fine dividing lines between safe and unsafe exposure. The risk conclusions reached 
should be interpreted with care and with a thorough understanding of the basis for these 
conclusions. AIOH disclaims liability with respect to the use of this guidebook. 
Acknowledgements 
The authors acknowledge the co-contributors of the first edition guideline, Deborah van Zanten and 
Gerard Tiernan, are also grateful to the members of the AIOH Exposure Standards Committee who 
proof read the document and provided valuable comment on various parts of the text. 
 
AIOH Risk Management Guidebook Page 5 
 
Contents 
 
PREFACE - WHAT IS THIS GUIDEBOOK ABOUT? ...................................................................................... 3 
Glossary of commonly used terms.......................................................................................................... 7 
Managing Risks to Workers’ Health ........................................................................................................ 9 
Step 1: Workplace characterisation .................................................................................................. 12 
Step 2: Hazard identification & consequence ................................................................................... 12 
Step 3: Exposure characterisation & likelihood ................................................................................15 
Step 4: Level of risk ........................................................................................................................... 19 
Step 5: Treatment / control of risks ................................................................................................. 19 
Step 6: Monitoring responses and reviewing risks ........................................................................... 21 
Step 7: Risk register and action plan ................................................................................................. 22 
Example case studies ........................................................................................................................ 23 
References ........................................................................................................................................ 25 
Appendix 1: Health Hazard Identification (HHI) Form ......................................................................... 28 
Appendix 2: Health Exposure Consequence Rating for Hazards.......................................................... 29 
Appendix 3: Health Exposure Likelihood Rating Descriptors ............................................................... 37 
BIOLOGICAL exposure rating descriptors ......................................................................................... 38 
Table 3.1: Process water - Qualitative water mist exposure descriptor (also covers Legionella) 38 
Table 3.2: Process water – Quantitative water mist exposure descriptor (based on Legionella 
count) ............................................................................................................................................ 39 
Table 3.3: Potable water - Qualitative biological and chemical exposure descriptor .................. 40 
Table 3.4: Vector-borne disease - Qualitative environmental and behavioural factor exposure 
descriptor ...................................................................................................................................... 40 
Table 3.5: Food borne pathogens - Qualitative design and behavioural factor exposure 
descriptor ...................................................................................................................................... 41 
CHEMICAL exposure rating descriptors ............................................................................................ 43 
Table 3.6: In-air exposure - Qualitative chemical exposure descriptor ........................................ 43 
Table 3.7: In-air exposure - Quantitative chemical exposure descriptor (based on SEG mean 8h 
TWA exposure relative to the OEL) ............................................................................................... 43 
Table 3.8: In-air exposure - Quantitative chemical exposure descriptor (based on SEG UCL 8hr 
TWA exposure relative to the OEL) ............................................................................................... 44 
Table 3.9: Dermal exposure - Qualitative chemical exposure descriptor ..................................... 44 
Table 3.10: In-air exposure – Semi-quantitative chemical exposure descriptor (based on 
chemical quantities, volatility / dustiness & ventilation control) ................................................. 44 
AIOH Risk Management Guidebook Page 6 
 
ERGONOMIC exposure rating descriptors ........................................................................................ 46 
Table 3.11: Musculoskeletal exposure - Qualitative ergonomic exposure descriptor (based on 
descriptive terms for body movement) ........................................................................................ 46 
Table 3.12: Musculoskeletal exposure - Qualitative ergonomic exposure descriptor (based on 
descriptive terms for loads and adverse factors) ......................................................................... 47 
Table 3.13: Vibration exposure – Qualitative hand-arm vibration exposure descriptor .............. 48 
Table 3.14: Vibration exposure – Quantitative hand-arm vibration exposure descriptor (based 
on SEG mean 8hr TWA exposure) ................................................................................................. 49 
Table 3.15: Vibration exposure – Qualitative whole-body vibration exposure descriptor .......... 50 
Table 3.16: Vibration exposure – Quantitative whole-body vibration exposure descriptor (based 
on SEG mean 8hr TWA exposure) ................................................................................................. 50 
NOISE exposure rating descriptors ................................................................................................... 51 
Table 3.17: Noise exposure – Quantitative noise exposure descriptor (Based on sound pressure 
levels) ............................................................................................................................................ 51 
Table 3.18: Noise exposure – Quantitative noise exposure descriptor (Based on SEG mean 8hr 
TWA exposure) .............................................................................................................................. 51 
RADIATION exposure rating descriptors ........................................................................................... 52 
Table 3.19: Ionising radiation – Quantitative physical exposure descriptor ................................ 52 
Table 3.20: UV light - Qualitative physical exposure descriptor ................................................... 53 
THERMAL exposure rating descriptors ............................................................................................. 53 
Table 3.21: Heat stress - Qualitative physical exposure descriptor .............................................. 53 
Appendix 4: Risk Assessment, Action Identification and Prioritisation ............................................... 55 
Appendix 5: SEG / Location / Equipment / Task Appraisal Form ......................................................... 56 
Appendix 6: Checklist for Risk Reduction Controls Form * .................................................................. 57 
Appendix 7: Remedial Action Table ..................................................................................................... 58 
 
 
AIOH Risk Management Guidebook Page 7 
 
Glossary of commonly used terms 
AIHA American Industrial Hygiene Association 
AIDS Aquired immunodeficiency syndrome 
AIOH Australian Institute of Occupational Hygienists 
ALARP As low as reasonably practicable 
ARPANSA Australian Radiation Protection and Nuclear Agency 
AS Australian Standard 
AS/NZS Australian Standard/New Zealand Standard 
A(8) Daily vibration exposure normalised to an 8 hour reference period 
BTRA Basic Thermal Risk Assessment 
°C degrees celcius 
cfu/mL colony forming units per mililitre 
CMR carcinogenic, mutagenic and reprotoxic agents 
CNS central nervous system 
COH® Certified Occupational Hygienist 
COSHH control of substances hazardous to health 
dB(A) A-weighted sound pressure level in decibels (dB) referenced to 20 micropascals 
dB(C) C-weighted sound pressure level in decibels (dB) referenced to 20 micropascals 
EC European Commission 
EU European Union 
eVDV estimated vibration dose value 
GHS Globally Harmonised System of classification and labelling of chemicals 
HACCP Hazard Analysis and Critical Control Points 
HAV hand-arm vibration 
HAZOP Hazard and operability study 
HCIS hazardous chemicals information system 
HHI Health Hazard Identification 
HIV human immunodeficiency disease 
HSE Health and Safety Executive (UK) 
IARC International Agency for Research on Cancer 
ICMM International Council on Mining and Metals 
IOGP International Association of Oil & Gas Producers 
IPIECA Global Oil and Gas Industry Association (originally the ‘International PetroleumIndustry Environmental Conservation Association’) 
ISO International Organization for Standardization 
Kg Kilograms 
L Litres 
LAeq,8hr eight-hour equivalent continuous A-weighted sound pressure level in decibels (dB) 
referenced to 20 micropascals 
LCL lower confidence limit 
LC,peak C-weighted peak sound pressure level in decibels (dB) referenced to 20 micropascals 
LEV local exhaust ventilation 
LRT lower respiratory tract 
mg/m3 milligrams (10-3 gm) per cubic metre 
AIOH Risk Management Guidebook Page 8 
 
m/s metres per second 
mSv millisieverts 
OEL occupational exposure limit 
OHS Occupational Health and Safety 
PCBU person in control of a business or undertaking 
PHS Predicted heat strain 
PPE personal protective equipment 
rms root mean square 
SDS safety data sheet 
SEG similar exposure group 
SPF Sun protection factor 
STEL short term exposure limit 
SWA Safe Work Australia 
TWA time weighted average 
TWL Thermal Work Limit 
UCL upper confidence limit 
UK United Kingdom 
URT upper respiratory tract 
UV ultraviolet 
UVR ultraviolet radiation 
WBV whole-body vibration 
WES workplace exposure standard 
WHS work health and safety 
WHO World Health Organization 
AIOH Risk Management Guidebook Page 9 
 
Managing Risks to Workers’ Health 
 
In many jurisdictions there are legal requirements to protect all who work on or visit work sites or 
premises from occupational illness or injury in a cost-effective manner. Risk management is a tool to 
achieve this goal. Generally, hazards must be identified and risks assessed and controlled, a process 
called risk management. 
The purpose of a health risk assessment should be to provide the necessary information and 
understanding of health risk to prevent acute and chronic health effects to the workers in a 
particular work group or location. Risk assessments should be conducted throughout the life cycle 
(all phases) of business operations, including reassessment every one or two years as required by 
changes in the work environment or operations. 
The Safe Work Australia (SWA, 2018a) Code of Practice ‘How to manage work health and safety 
risks’ describes a process of managing risk to help you decide what is reasonably practicable in 
particular situations in order to meet duty of care under the Australian WHS laws1. The Code of 
Practice involves four steps: 
• identify hazards – find out what could cause harm; 
• assess risks if necessary – understand the nature of the harm that could be caused by the 
hazard, how serious the harm could be and the likelihood of it happening; 
• control risks – implement the most effective control measure that is reasonably practicable 
in the circumstances; and 
• review control measures to ensure they are working as planned. 
It emphasises the need to consult with the workforce. It also notes that where a hazard and its 
associated risks are well known and have well established and accepted control measures, the 
requirement to formally assess the risk may be unnecessary. If, after identifying a hazard, you 
already know the risk and how to control it effectively, you should simply record the result of the risk 
assessment and implement the controls. 
This guidebook draws strongly from the following publications: ‘Risk Management – Guidelines’ 
AS/NZS ISO 31000, 2018) and ‘A Strategy for Assessing and Managing Occupational Exposures’ 
(Ignacio & Bullock, 2006). The reader is encouraged to also consult these. Other relevant 
publications include: ‘Risk Assessment Principles for the Industrial Hygienist’ (Jaycock et al, 2000), 
‘Good Practice Guidance on Occupational Health Risk Assessment’ (ICMM, 2016), ‘A roadmap to 
health risk assessment in the oil and gas industry’ (IPIECA & IOGP, 2006) and ‘Health management in 
the oil and gas industry’ (IPIECA & IOGP, 2019). 
In order to clearly understand the nature of a risk assessment, it is important to be able to 
distinguish between the term ‘hazard’ and ‘risk’, as used throughout this guidebook. 
 
A HAZARD is a source of potential harm. 
RISK is a function of likelihood and consequences of hazards; it is the possibility that 
harm may occur when exposed to a hazard. 
 
AIOH Risk Management Guidebook Page 10 
 
Risk control means taking action to eliminate risks so far as is reasonably practicable, and if that is 
not possible, minimising the risks so far as is reasonably practicable. 
Many people carry out risk assessments on a day-to-day basis during the course of their work. They 
note changes in working practices, they recognise unsafe working conditions and practices, and 
often they take appropriate corrective action. However, risk assessment needs to be conducted 
systematically to deliver real and lasting benefits to worker health. As presented in AS/NZS ISO 
31000 (2018), risk management should be an iterative process consisting of well-defined steps 
which, taken in sequence, support better decision-making by contributing a greater insight into risks, 
and facilitate continual improvement (Figure 1). 
Figure 1: Risk management process schematic (adapted from AS/NZS ISO 31000) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OK 
Not OK 
Characterise Workplace – Establish SEGs 
(see Step 1) 
Identify Hazards & their health impact. Relate 
them to a point on the consequence scale (see 
Step 2) 
Consider the likelihood of exposure that could 
result in the health impact or consequence 
under consideration (see Step 3) 
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Treat / Control Risks 
(see Step 5) 
AIOH Risk Management Guidebook Page 11 
 
This guidebook focuses on a procedure for a baseline screening health risk assessment. The baseline 
risk assessment will frequently be qualitative in nature, however later iterations are likely to 
become more quantitative to reduce uncertainty of the risk assessment. Quantitative risk 
assessment will require the input of a Certified Occupational Hygienist (COH®),2 following the 
requirements of the AIOH guidebook ‘Occupational Hygiene Monitoring and Compliance Strategies’ 
(Grantham & Firth, 2014). Quantitative risk assessment for some ergonomics aspects may take a 
different form to that used here and should be guided by a Certified Professional Ergonomist.3 
The basis of an occupational health risk program is that the potential risk to a person’s health is a 
function of both the magnitude and frequency of the exposure to the hazard and the inherent 
capacity of the hazard to cause harm (the health effect or consequence). The magnitude and 
frequency of exposure will determine the ‘likelihood’ of a health impact (or consequence). 
A suitable and sufficient occupational health risk management program requires the following 
elements: 
1. Workplace characterisation; 
2. Hazard identification; 
3. Exposure characterisation; 
4. Risk assessment; 
5. Risk control or treatment; 
6. Ongoing monitoring and review of control adequacy; and 
7. Documentation of the risks identified and the actions decided upon. 
These are expanded on in later sections of this guidebook. The use of ‘hazard identification’ and 
‘timely hazard control’ as elements of a health and safety program, have been shown to have the 
highest influence in reducing OHS violations in small high-hazard US companies (Akbar-Khanzadeh & 
Wagner, 2001); this is a measurable benefit besides that of having healthy workers. 
People with adequate knowledge and experience in determining risk levels are needed for both the 
risk assessment phase and to consider the implications of proposed risk reduction strategies such as 
plant and equipment upgrades and modifications.A thorough risk assessment requires the co-
operation of plant managers, team leaders and specialist resources in occupational health and 
occupational hygiene, as well as input from workers. The input of other specialists (e.g. 
ergonomists) may also be required. The creation of a representative team for risk assessment is 
essential to ensure ‘ownership’ of the assessment outcomes. 
The outcome of the occupational health risk management process should be the prioritisation of 
potential health risks in order to facilitate the drafting of: 
• An action plan to cost-effectively eliminate or reduce adverse exposures; and 
• Occupational hygiene and medical surveillance monitoring programs, where required. 
 
2 A list of Certified Occupational Hygienists can be found at https://www.aioh.org.au/member-centre/find-an-
occupational-hygienist (accessed 7/01/2020). 
3 A list of Certified Professional Ergonomists and their particular skills can be found at 
https://www.ergonomics.org.au/find-a-cpe (accessed 7/01/2020). 
https://www.aioh.org.au/member-centre/find-an-occupational-hygienist
https://www.aioh.org.au/member-centre/find-an-occupational-hygienist
https://www.ergonomics.org.au/find-a-cpe
AIOH Risk Management Guidebook Page 12 
 
The aim should be to identify the significant risks in the workplace, ideally at the design stage (e.g. 
by using HAZOP4). These risks should not be obscured by an excess of information. 
Senior management should review the risk management process to ensure continuous 
improvement. 
Step 1: Workplace characterisation 
The workplace can be characterised according to: 
• Worker groups who have similar responsibilities and so would be expected to have similar 
exposure to the same range of hazards, termed ‘Similar Exposure Groups’ (SEGs)5. SEGs 
could be based on payroll classifications or personnel employee job (occupation) codes plus 
job observation / interview (for a more detailed discussion, refer to Section 7.1 in Grantham 
& Firth, 2014); 
• Location or equipment used, such as looking at the boilermaker’s workshop, electrical trades 
workshop, spray painting booth, grader operator, etc.; or 
• Hazard type, such as noise, hazardous substances, etc. 
The first two approaches are most often taken, with the first being preferred. 
Step 2: Hazard identification & consequence 
Health hazards in each work area or SEG should be identified and a hazard inventory that includes all 
the biological, chemical, ergonomic and physical hazards compiled (see Appendix 1 for a possible 
format). The inventory could include any or all of the following: 
• materials handling / processing 
▪ ores / process materials, 
▪ process streams, 
▪ wastes and by-products, 
• construction materials 
▪ metals and welding processes / consumables, 
▪ insulation, 
▪ refractory, 
▪ paints and coatings, 
▪ glues, 
▪ solvents, 
• maintenance materials 
▪ cleaning agents, 
 
4 Hazard and operability study - https://en.wikipedia.org/wiki/Hazard_and_operability_study (accessed 
7/01/2020). 
5 Ignacio & Bullock (2006) defined SEGs as “groups of workers having the same general exposure profile 
because of the similarity and frequency of the tasks they perform, the materials and processes with which 
they work, and the similarity of the way they perform the tasks”. 
https://en.wikipedia.org/wiki/Hazard_and_operability_study
AIOH Risk Management Guidebook Page 13 
 
▪ lubricants, 
▪ fuels, 
• general workplace hazards 
▪ manual handling, 
▪ ionising and non-ionising radiation sources, 
▪ noise, 
▪ vibration, 
▪ biological contaminants, 
▪ extreme heat / humidity or cold, 
▪ fatigue 
• laboratory chemicals, 
• pharmaceutical products. 
The following should be considered to assist with hazard identification: 
• a review of the inventory of materials / chemicals used and their safety data sheets (SDSs); 
• a review of the plant process flow diagrams (e.g. tracking of trace amounts of highly toxic 
substances such as cadmium, arsenic and mercury); 
• a walk-through survey and discussions with plant personnel, looking at the plant, its 
processes, equipment, materials use, physical environment, products / by-products, 
effluents, etc; 
• the hours of work e.g. hours of work greater than an 8-hour day, 5-day week (40-hour week) 
and range of tasks, both routine and occasional in the plant; 
• a study of any history of disease or illness from medical records, respecting confidentiality 
requirements; 
• a review of relevant legislation; 
• a review of documented specialist advice (e.g. from trade associations, standards or 
professional institutes) or information from similar types of operations; and 
• a review of any occupational hygiene or health monitoring data, respecting confidentiality 
requirements; 
• a review of the minutes of health and safety meetings; 
• the presence of any susceptible individuals such as pregnant or breast-feeding mothers. 
AIOH Risk Management Guidebook Page 14 
 
 
Once hazards have been identified the consequence for each hazard needs to be determined. A 
five-point qualitative consequences scale will be used in this guidebook, with 5 being the most 
significant consequence and 1 being the least significant consequence. While a quantitative 
measure of consequence would be preferred, such as by determination of attributable risks from 
epidemiological studies of hazard-disease combinations, this approach is limited by data availability 
and the fact that historic response data do not reflect the risks associated with current exposures. 
The following descriptors are used to define each level on the consequences scale. Alternative but 
similar descriptors are available from IPIECA & IOGP (2006) and ICMM (2016). 
5 Severe can potentially cause fatality, cancer or reproductive / genetic health effects 
to one or more people resulting from chemical, physical or biological agent 
exposures. 
4 Major can potentially cause irreversible health effects or disabling illness to one or 
more people resulting from chemical, physical or biological agent exposures. 
3 Moderate can cause severe, reversible health effects of concern - could result in a lost 
time illness. 
2 Minor can cause reversible health effects of concern that would typically result in a 
medical treatment with no lost time. 
1 Negligible can cause reversible health effects of little concern (e.g. temporary 
discomfort), requiring first aid treatment at most. 
 
It should be noted that the ‘Severe’ and ‘Major’ consequences can include carcinogenic, mutagenic, 
and reprotoxic (CMR) agents, with the former category including probable CMRs and the latter 
suspected. Occupational cancers are estimated to account for 57% of the annual number of work-
related deaths (Takala et al, 2014). In Australia, Fritschi and Driscoll (2006) estimate that 5,000 
invasive cancers and 34,000 non-melanoma skin cancers per year are caused by occupational 
exposures and 1.5 million workers are exposed to known carcinogens. Some carcinogens have been 
identified as presenting an unacceptable risk to workers and are prohibited or have restricted uses6. 
 
6 Refer to the Safe Work Australia website on ‘Carcinogens’ - 
https://www.safeworkaustralia.gov.au/carcinogens (accessed 7/01/2020). 
Note: Health risk assessments are usually generic. It is impossible to assess how each 
individual will react to every health risk. Factors that influence this variability include: heredity, 
age, sex, personal habits (e.g. smoking, alcohol and substance abuse / dependence), medical 
and occupational history as well as health status. Another complication is that people are 
exposed to health hazards in every aspect of their lives, including home, hobbies and leisure, as 
well as work. 
Consequence is the potential outcome or impact of a hazard. The inherent capacity of a 
health hazard to cause harm equates to ‘consequences’.https://www.safeworkaustralia.gov.au/carcinogens
AIOH Risk Management Guidebook Page 15 
 
The tables in Appendix 2 list general categories of health impacts under each of the five points on 
the consequences scale. In addition, individual hazardous agents are tabulated at the end of 
Appendix 2. If the hazards identified do not fall into the general categories or are not listed in the 
hazardous agents table then further information regarding the health impact of the hazard must be 
sought in order to determine the relevant point on the consequences scale. It may be possible for a 
particular hazard to have more than one consequence. For example, occupational exposure to 
crystalline silica can cause lung cancer but it may also cause lung fibrosis (silicosis). It may also be 
possible for agents to interact additively (act together on the same organ) or synergistically (one 
hazard enhances the negative effects of another). Examples are MEK and n-hexane, or noise and 
toluene. For such agents or effects, further investigation or expert assistance may be required to 
determine which consequence is the most relevant for the workplace under consideration. 
 
Step 3: Exposure characterisation & likelihood 
Likelihood is a descriptor of the probability / frequency of exposure leading to the particular 
consequence that is associated with the hazard under consideration. In determining likelihood, it is 
necessary to consider the exposure to a hazard and the probability that harm will occur following 
that exposure. Exposure may be viewed in terms of frequency or time, that is, how often or how 
long one is exposed, and the concentration, or the level, of the contaminant or agent. Appendix 3 
provides tables with qualitative and quantitative descriptions of exposure. Some of these consider 
the time of exposure only and some consider the concentration as well. 
Likelihood is expressed in terms of the following five-point scale: 
A Almost certain regular contact with the potential hazard at very high levels 
B Likely periodic contact with the potential hazard at very high levels or regular 
contact with the potential hazard at high levels 
C Possible periodic contact with the potential hazard at high levels or regular 
contact with the potential hazard at moderate levels 
D Unlikely periodic contact with the potential hazard at moderate levels or regular 
contact with the potential hazard at low levels 
E Rare periodic contact with the potential hazard at low levels 
The tables in Appendix 3 provide qualitative or semi-quantitative descriptions of exposure for each 
of these five points on the likelihood scale. The descriptors are provided for a number of types of 
hazards: 
Note: For the initial qualitative risk assessment, a conservative consequence should be used as 
described in Appendix 2, and should not be reduced unless the hazard is either eliminated or 
there has been a quantitative assessment. Only the degree of exposure, and therefore the 
likelihood of the consequence, can change the risk at this stage. When conducting quantitative 
risk assessment using a Certified Occupational Hygienist (COH), a maximum reasonable 
consequence should be used according to expert advice from the COH. 
AIOH Risk Management Guidebook Page 16 
 
• Biological; 
• Chemical; 
• Ergonomic (including vibration); 
• Noise; 
• Radiation; and 
• Thermal. 
If quantitative exposure levels are not known or not available, then qualitative descriptions should 
be used. However, it may be necessary to conduct quantitative assessment where: 
• Exposures could exceed, or have exceeded, an occupational exposure limit (OEL) or 
workplace exposure standard (WES) (SWA, 2019); 7 
• Exposures have aroused complaints or adverse symptoms directly or indirectly related to 
chemical or physical agents in the workplace; 
• There is a recommendation from an occupational health professional such as an 
occupational physician as part of an investigative process; 
• Exposures are the result of a change in activities or processes that could potentially increase 
exposures; 
• Exposures are to CMR agents (known and suspected), including ionising radiation; or 
• Required by regulations. 
Exposure measurement is used to decide whether workers’ exposure exceeds the relevant OEL / 
WES, or to identify where or when the controls should be applied. Occasionally it may be used to 
identify the type of control that is needed or the effectiveness of a control. If it is clear that 
exposure can be reduced with the use of simple controls, or that current exposure results in an 
obvious risk to health, then controls should be implemented and subsequent exposure 
measurement used to confirm that the controls are effective. 
Hazards with very low exposure potential should be documented but need not be further assessed. 
However, this assessment must be reviewed periodically to ensure that there has not been a 
degradation of controls or process change leading to an increase in exposure. 
When assessing the likelihood of exposure at the workplace resulting in the consequence or health 
effect under consideration for a particular agent, the following steps should be considered: 
• review data with respect to the following: 
o summarised employee health checks (uphold all confidentiality requirements and anti-
discrimination laws); 
o personal exposure measurement. Good quality data is critical (see the Occupational 
Hygiene Monitoring and Compliance Strategies guidebook); 
o measurements conducted in the general workplace; 
 
7 The Safe Work Australia website provides OELs / WESs in the Hazardous Chemical Information System (HCIS). 
http://hcis.safeworkaustralia.gov.au/ (accessed 7/01/2020). 
http://hcis.safeworkaustralia.gov.au/
AIOH Risk Management Guidebook Page 17 
 
o specific operations e.g. production data, chemical handling, etc. 
• consider the relevance of these data in relation to the OEL / WES, duration of exposure, 
individual susceptibility, etc. 
• combine this with the exposure descriptors in Appendix 3 and determine an exposure 
likelihood rating for each SEG, job, location or task for each relevant hazard. This rating 
must incorporate existing control equipment (e.g. engineering controls, isolation, etc) and 
procedures. However, it may also be useful to determine an exposure likelihood rating for 
the ‘uncontrolled’ situation. 
 
A guide to the exposure descriptors given in Appendix 3 is as follows: 
• Biological hazards 
o Use Table 3.1 when defining the water mist exposure potential qualitatively based on 
the perceived “dirtiness” of the water or on poor maintenance. 
o Use Table 3.2 when defining the water mist exposure potential quantitatively using 
Legionella counts in water. 
o Use Table 3.3 when defining drinking water exposure potential qualitatively using 
potential to exceed biological limits on a yearly basis. 
o Use Table 3.4 when defining vector-borne disease potential qualitatively using 
environmental and behavioural exposure factors. 
o Use Table 3.5 when defining the potential for food-borne pathogens qualitatively using 
design and behavioural exposure factors. 
• Chemical hazards 
o Use Table 3.6 when defining in-air exposure potential qualitatively based on the 
perceived concentration of exposure. 
o Use Table 3.7 when defining the in-air exposure potential quantitatively as an estimate 
of the SEG arithmetic mean of the exposure profile relative to the time-weighted 
average occupational exposure standard (TWA-OEL) (i.e. as a percentage of the OEL)7. 
(These values can be used not only as a performance indicator, but also as a guide to 
frequency of air monitoring). 
o Use Table 3.8 when defining the in-air exposure potential as an estimate of the 95% 
upper confidence limit (UCL) of the SEG exposure profile relative to the OEL. 
Note: The risk assessment should be conductedas high as possible in the site hierarchy. That is, 
as an example, if the whole site is exposed to UV light at the same level, then the risk 
assessment of UV light can be done once at a sitewide level. It is not required to be done for 
individual SEGs, tasks, areas, etc. If a particular hazard is only present in a particular SEG or area, 
it only needs to be assessed in that SEG or area. 
AIOH Risk Management Guidebook Page 18 
 
o Use Table 3.9 when defining dermal exposure potential qualitatively. 
o Use Table 3.10 when defining the in-air exposure potential qualitatively based on the 
amount and volatility (or “dustiness”) of the substance in use and on the type of 
ventilation. 
o Use Table 3.3 when defining drinking water exposure potential qualitatively using 
potential to exceed toxic agent limits on a yearly basis. 
• Ergonomic hazards 
o Use Table 3.11 when defining exposure potential qualitatively based on descriptive 
terms for body movement. 
o Use Table 3.12 when defining exposure potential qualitatively based on descriptive 
terms for loads and factors that adversely affect the musculoskeletal system. 
o Use Table 3.13 when defining hand-arm vibration (HAV) exposure potential qualitatively 
based on time of use of a range of machinery. 
o Use Table 3.14 when defining HAV exposure potential quantitatively in comparison with 
OELs. 
o Use Table 3.15 when defining whole-body vibration (WBV) exposure potential 
qualitatively based on time of exposure. 
o Use Table 3.16 when defining WBV exposure potential quantitatively in comparison 
with OELs. 
• Noise hazard 
o Use Table 3.17 when defining exposure potential quantitatively based on area sound 
pressure levels. 
o Use Table 3.18 when defining SEG exposure potential quantitatively based on 
assessment against recognised noise exposure limit values. 
• Radiation hazard 
o Use Table 3.19 when defining ionising radiation exposure potential quantitatively based 
on effective dose. 
o Use Table 3.20 when defining ultraviolet radiation (UVR) exposure potential 
qualitatively using skin type and the UV index. 
• Thermal hazard 
o Use Table 3.21 when defining heat stress exposure potential qualitatively using a basic 
thermal risk assessment. 
AIOH Risk Management Guidebook Page 19 
 
Step 4: Level of risk 
Determining the level of risk allows the prioritising of control action, and the monitoring and / or 
assessing of the adequacy of controls. 
The risk assessment is conducted using a risk matrix to determine relative (not absolute) risk (see 
Appendix 4). The matrix axes are the consequence (health effect - see Appendix 2) and the 
likelihood (exposure - see Appendix 3). 
The outcome of the risk assessment will determine the action required – this will be implementation 
of controls, information gathering, a combination of the two or no action. Generally, the need for 
further information will be greater if the information that the risk assessment was based upon has a 
high degree of uncertainty, for example if there is limited exposure data or high variability of results. 
A health risk rating / uncertainty rating matrix is provided in Appendix 4 to assist with the decision to 
seek further information and / or to implement controls. “Active monitoring” may include exposure 
measurement, regular inspection / observation on site, recording / reporting system, etc. 
There are four possibilities for the risk assessment outcome: 
• Extreme - needs urgent and immediate control or mitigation and senior executive 
management attention; 
• High - requires proactive management8 to control or mitigate adverse exposures; 
• Medium - requires active monitoring; and 
• Low - will likely not require active management, other than existing routine procedures. 
This risk assessment process should be repeated at appropriate intervals, usually less than 5 years or 
when an agent or the process changes. 
Step 5: Treatment / control of risks 
The action identification and prioritisation of controls is determined using the results of the risk 
assessment. The results can be transcribed onto a risk appraisal form for the relevant SEG, location, 
equipment or task (see Appendix 5). 
Where risk assessment indicates the need for controls or treatment, these must be assessed as to 
their efficacy in minimising or eliminating the risk of adverse health effects in a staged manner 
according to the hierarchy of controls: 
1. Elimination of the hazard (e.g. process automation). Don’t use the substance / material or 
process - the permanent solution. 
2. Substitution / reduction with a less harmful version or process. Find a safer substance / 
material or better way to perform the process. 
 
8 Proactive management refers to managing adverse exposures with strategies that address expected issues 
before they happen in an effort to mitigate risk. 
AIOH Risk Management Guidebook Page 20 
 
3. Isolation of the hazard from people at the workplace (e.g. enclosure with local exhaust 
ventilation; LEV). Keep it away from the worker. 
4. Engineering controls, which includes process redesign. Engineer a better way. 
5. Procedures and training, which includes redesigning work systems and administrative 
controls such as rotation of personnel. 
6. Personal Protective Equipment (PPE) use by people at the workplace (the last line of 
defence). 
Often there are specific control requirements for CMR agents, including reducing their use by 
replacing them with agents and processes that pose less or no danger. Collective controls such as 
physical enclosure, LEV and mechanisation of specific procedures should be implemented 
preferentially over the use of PPE (e.g. gloves, gowns, overalls, boots and face shields). The use of 
PPE should be limited to situations when all other measures either cannot be applied or are not 
sufficiently effective. 
A risk reduction controls form is included in Appendix 6 to assist with the selection of controls. 
Exposures should be “as low as reasonably practicable” (ALARP). 
Whenever practicable, purchasing criteria should be developed such that new equipment brought to 
site will eliminate or minimise exposure and at a minimum not expose workers to more than the OEL 
in operating mode. Control systems should be: 
• Designed to be compatible with process and maintenance requirements; 
• Designed according to good occupational hygiene engineering practices; 
• Cost effective at achieving control of potentially hazardous exposures; and 
• Regularly maintained and monitored for their efficacy. 
Administrative controls must be appropriate. Where work practices are used for exposure control, 
they must be understood and followed as a result of training and enforcement. Safe handling 
procedures and precautions should be included in standard operating procedures. 
Where risk assessment indicates the need to reduce exposures to toxic or radioactive substances, 
good personal hygiene must be enforced. The program must include: 
• No smoking, eating or drinking in designated hazard areas; 
• Washing of hands and face prior to eating or smoking; 
• Showering at work post shift or after exposure to ‘dirty’ conditions; 
• Laundering of contaminated clothing by the PCBU; and 
• Clean shaven personnel where respiratory protective equipment requiring a face seal is 
used, plus formal fit testing of the respirator. 
AIOH Risk Management Guidebook Page 21 
 
PPE must only be used to achieve compliance with OELs in situations where the use of higher-level 
controls is not commensurate with the degree of risk and cost, while higher level control options are 
being developed and implemented, or for short duration tasks. Where PPE is required, it must be 
provided, be appropriate and be managed effectively, such that: 
• A single individual / function should be assigned overall accountability for the PPE program 
for thesite; 
• The program must be adequately documented, to include contractors; 
• The program must specify selection, administration, maintenance and replacement of PPE, 
training, and designate responsibilities, and include signposting for PPE use; 
• The program must be consistent with local standards or regulations; 
• PPE of the proper types must be readily available and their use (where required) must be 
enforced. Defective or damaged PPE must be replaced; 
• Protective equipment requirements must be indicated in operating manuals, and procedures 
must be posted in hazardous areas and included in employee training; 
• Employees must be trained in the health effects of exposures to specific hazards, when to 
use which PPE, how to fit it correctly, how to identify when it is no longer effective, what to 
do if it fails and how to maintain it; and 
• PPE use must be reviewed regularly for continued relevance. 
The requirements of the latest versions of AS/NZS 1715, Selection, use and maintenance of 
respiratory protective devices, AS/NZS 1269, Occupational noise management, and AS/NZS 2161.1, 
Occupational protective gloves - Selection, use and maintenance, all available from Standards 
Australia9, should be followed. 
COSHH Essentials, free software available from the UK Health and Safety Executive (HSE), can also be 
used to provide advice on controlling the use of chemicals for a range of common tasks (e.g. mixing, 
or drying). COSHH Essentials was developed to help businesses comply with the Control of 
Substances Hazardous to Health Regulations (COSHH), and is a form of risk banding.10 
Step 6: Monitoring responses and reviewing risks 
Controls can often fail due to them falling into disrepair or due to the process changing without 
concomitant change in the controls. There is a need to ensure that exposure risk is assessed on an 
ongoing basis, not just when the control is implemented. The risk assessment should reach one or a 
combination of the following conclusions for each exposure type: 
• The risk is controlled by engineering and process controls; 
 
9 Standards are available from https://infostore.saiglobal.com/. 
10 UK Health and Safety Executive. COSHH Essentials. http://www.hse.gov.uk/coshh/essentials/index.htm 
(accessed 7/01/2020). 
http://www.hse.gov.uk/coshh/essentials/index.htm
https://infostore.saiglobal.com/
http://www.hse.gov.uk/coshh/essentials/index.htm
AIOH Risk Management Guidebook Page 22 
 
• The risk is mitigated by the use of PPE or procedures and training. Substitution / isolation / 
engineering controls must be considered and any reasons for their not being adopted 
documented; 
• There are insufficient data to make a valid assessment. This must be coupled with a 
statement on the time scale over which valid data will be acquired; or 
• There is a health risk at current exposures. This must be coupled with an action plan and 
time scale to control the identified risks. 
For CMRs (known and suspected), and sensitisers or allergens meeting an OEL is not adequate; 
exposures must be as low as reasonably practicable (ALARP). Meeting the OEL for sensitised 
individuals is not adequate as they can / may react to very low levels of exposure. Sensitised 
individuals should not be further exposed to the substance to which they have become sensitised. 
There should be an annual documented review of exposure controls for these substances. 
Recommended control actions should include whether or not employee health surveillance is 
required, in which case ‘Health Monitoring for Exposure to Hazardous Chemicals – Guide for Medical 
Practitioners’ (SWA, 2013a) should be consulted. 
Step 7: Risk register and action plan 
The risk management process should produce a comprehensive Risk Register that lists all of the key 
risks that could impact on worker health (see Appendix 1 & 5). 
The Risk Register should contain the following information for each identified risk: 
• Unique reference number; 
• Date of risk assessment; 
• Review date; 
• Description of the risk – what can happen and how if appropriate; 
• An outline of existing controls; 
• The consequence and likelihood of the consequence given the controls in place; 
• The risk level; 
• The overall priority of the risk; 
• The status of any additional controls required; and 
• The responsible officer. 
The risk register should be used to prepare an action plan for management with clear 
accountabilities (see Appendix 7). Senior management should review the risk management process 
to ensure continuous improvement. 
 
AIOH Risk Management Guidebook Page 23 
 
Example case studies 
Example 1: Lead dust in a busy radiator manufacturing workshop. Uncontrolled exposure to lead 
dust resulting in levels 10 times the OEL. 
Consequence = Severe; Likelihood = Almost Certain, hence EXTREME risk, 'without controls' – must 
provide urgent and immediate attention. 
With provision of local exhaust ventilation, planned regular housekeeping and delineation of eating 
and work areas, exposures are reduced to 10 – 50% of OEL. 
Consequence = remains the same; Likelihood = Unlikely, hence HIGH risk – must implement proactive 
management. 
Example 2: Arsenic levels and cancer in a smelter: Workers are exposed to arsenic in air levels ten 
times the OEL on a daily basis. 
Consequence = Severe; Likelihood = Almost Certain, hence EXTREME risk, 'without controls' – must 
provide urgent and immediate attention. 
With use of a comprehensive respiratory protection program, exposures are reduced to 10-50% of the 
OEL. 
Consequence = remains the same; Likelihood = Unlikely, hence now a HIGH risk – must implement 
proactive management. Strictly enforce use of PPE, maintain active monitoring and regularly review 
results, develop engineering controls, educate workers in hazards. 
Example 3: Diesel particulate in a maintenance workshop: Uncontrolled exposure in a closed 
workshop may result in levels 10-50% OEL. 
Consequence = Severe; Likelihood = Unlikely, hence HIGH risk - must implement proactive 
management. 
Maintain active monitoring and regularly review results, develop engineering controls, use local 
exhaust ventilation where possible, improve fuel quality, improve exhaust filtration on units, educate 
workers in hazards. 
Consequence = remains the same; Exposure cannot be reduced to < 10% OEL therefore likelihood will 
not change. Therefore, risk remains HIGH. Proactive management to continue. Also need to consider 
controls that reduce the consequence – elimination or substitution. Investigate the use of electric 
vehicles. This would eliminate the hazard in this case removing the risk. 
Example 4: Noise exposure for a mobile equipment operator: Uncontrolled exposure working on 
trucks, a front-end loader and a grader averages 97 dB(A). This is more than 10 times the 85 dB(A) 
OEL. 
Consequence = Major; Likelihood = Almost Certain, hence EXTREME risk – must provide urgent and 
immediate attention. 
An enclosed cab and hearing protection are provided to reduce exposure below 82 dB(A). 
AIOH Risk Management Guidebook Page 24 
 
Consequence = remains the same; Likelihood = Unlikely, hence now a MEDIUM risk – must maintain 
active monitoring. 
Example 5: Whole-body vibration on dozers: Uncontrolled exposure for full shifts results in levels 
over the OEL. 
Consequence = Moderate; Likelihood = Likely, hence HIGH risk – must provide proactive management. 
Installation of good seating that won’t bottom out will likely reduce exposures to 50-100% OEL. 
Consequence = remains the same; Likelihood = Possible, hence now a MEDIUM risk – must maintain 
active monitoring. 
Example 6: Outdoor work and UV exposure: Uncontrolled exposure in the outdoors for more than 2 
hours around noon on a clear day will provide more than 10 times the OEL exposure. 
Consequence = Severe; Likelihood = Almost Certain, henceEXTREME risk – must provide urgent and 
immediate attention. 
Implement compulsory use of broad-spectrum SPF 50+ sunscreen, provide training for all employees, 
supervisors and managers to increase their knowledge of the effects of UV radiation, the importance 
of the sun protection strategies and the benefits of early detection and skin self-examination. 
Consequence = remains the same; Likelihood = Unlikely, hence now a HIGH risk – must implement 
proactive management. 
Investigate provision of temporary shade structures, relocating tasks to shaded areas, rescheduling 
work to times with less UV intensity (that is, before 10 am and after 3 pm), use of protective clothing 
and equipment (for example collared, long sleeved shirts, trousers or long-sleeved overalls, broad 
brimmed/bucket hats or hard hat brim attachments, sunglasses that comply with standard AS 1067). 
Consequence = remains the same; Likelihood = Rare, hence now a MEDIUM risk – must maintain active 
monitoring. 
Example 7: On-site food preparation: The site facility is not located, constructed and maintained 
according to sanitary design principles; suppliers do not have in place effective food safety programs; 
cleaning and sanitation procedures are not always followed; and not all personnel follow personal 
hygiene requirements. 
Consequence = Moderate (may result in a lost time incident); Likelihood = Almost Certain, hence HIGH 
risk – must implement proactive management. 
Implement effective food safety programs for suppliers, assure that cleaning and sanitation 
procedures are always followed and that all personnel follow personal hygiene requirements. 
Consequence = remains the same; Likelihood = Unlikely, hence now a MEDIUM risk – must maintain 
active monitoring. 
 
AIOH Risk Management Guidebook Page 25 
 
References 
Akbar-Khanzadeh F & OD Wagner (2010). Safety and health program assessment in relation to the 
number and type of safety and health violations. Am Ind Hyg Assoc J, 62(5); pp 605-610. 
ARPANSA (2005). Code of Practice and Safety Guide for Radiation Protection and Radioactive Waste 
Management in Mining and Mineral Processing. Australian Radiation Protection and Nuclear 
Agency. https://www.arpansa.gov.au/regulation-and-licensing/regulatory-publications/radiation-
protection-series (accessed 7/01/2020). 
ARPANSA (2014). Fundamentals – Protection Against Ionising Radiation. Australian Radiation 
Protection and Nuclear Agency. https://www.arpansa.gov.au/regulation-and-licensing/regulatory-
publications/radiation-protection-series (accessed 7/01/2020). 
AS 2670.1 (2013). Evaluation of human exposure to whole-body vibration - General requirements. 
Standards Australia. https://infostore.saiglobal.com/en-au/Standards/AS-2670-1-2001-R2016-
Amdt-1-2013-123968_SAIG_AS_AS_282860/ (accessed 7/01/2020). 
AS/NZS 3666.3 (2011). Air-handling and water systems of buildings - Microbial control Performance-
based maintenance of cooling water systems. Standards Australia. 
https://infostore.saiglobal.com/en-au/Standards/AS-NZS-3666-3-2011-
116882_SAIG_AS_AS_267807/ (accessed 7/01/2020). 
AS/NZS ISO 31000 (2018). Risk Management - Guidelines. Standards Australia. 
https://infostore.saiglobal.com/en-au/Standards/AS-ISO-31000-2018-
1134720_SAIG_AS_AS_2680492/ (accessed 7/01/2020). 
Di Corleto, R, I Firth & J Mate (2013). A Guide to Managing Heat Stress: Developed for use in the 
Australian Environment. Australian Institute of Occupational Hygienists (AIOH), Melbourne. 
https://www.aioh.org.au/resources/publications1/publications (accessed 7/01/2020). 
EU Directive 2002/44/EC. Directive on the minimum health and safety requirements regarding the 
exposure of workers to the risks arising from physical agents (vibration). Council of the European 
Union. https://osha.europa.eu/en/legislation/directives/19 (accessed 7/01/2020). 
Faulkner, S (2003). Prevention of hand-arm vibration syndrome. J Occup Health & Safety: Australia 
and New Zealand, 19(4); pp 371-379. 
Fritschi, L & T Driscoll (2006). Cancer due to occupation in Australia. Aust N Z J Public Health, 30(3); 
pp 213-219. https://www.ncbi.nlm.nih.gov/pubmed/16800196/ (accessed 7/01/2020). 
Grantham, D & I Firth (2014). Occupational Hygiene Monitoring and Compliance Strategies. 
Australian Institute of Occupational Hygienists (AIOH). 
https://www.aioh.org.au/resources/publications1/publications/occupational-hygiene-monitoring-
and-compliance-strategies (accessed 7/01/2020). 
ICMM (2016). Good Practice Guidance on Occupational Health Risk Assessment. International 
Council on Mining & Minerals, 2nd edition. https://www.icmm.com/en-gb/health-and-
safety/health/health-risk-assessment (accessed 7/01/2020). 
https://www.arpansa.gov.au/regulation-and-licensing/regulatory-publications/radiation-protection-series
https://www.arpansa.gov.au/regulation-and-licensing/regulatory-publications/radiation-protection-series
https://www.arpansa.gov.au/regulation-and-licensing/regulatory-publications/radiation-protection-series
https://www.arpansa.gov.au/regulation-and-licensing/regulatory-publications/radiation-protection-series
https://infostore.saiglobal.com/en-au/Standards/AS-2670-1-2001-R2016-Amdt-1-2013-123968_SAIG_AS_AS_282860/
https://infostore.saiglobal.com/en-au/Standards/AS-2670-1-2001-R2016-Amdt-1-2013-123968_SAIG_AS_AS_282860/
https://infostore.saiglobal.com/en-au/Standards/AS-NZS-3666-3-2011-116882_SAIG_AS_AS_267807/
https://infostore.saiglobal.com/en-au/Standards/AS-NZS-3666-3-2011-116882_SAIG_AS_AS_267807/
https://infostore.saiglobal.com/en-au/Standards/AS-ISO-31000-2018-1134720_SAIG_AS_AS_2680492/
https://infostore.saiglobal.com/en-au/Standards/AS-ISO-31000-2018-1134720_SAIG_AS_AS_2680492/
https://www.aioh.org.au/resources/publications1/publications
https://osha.europa.eu/en/legislation/directives/19
https://www.ncbi.nlm.nih.gov/pubmed/16800196/
https://www.aioh.org.au/resources/publications1/publications/occupational-hygiene-monitoring-and-compliance-strategies
https://www.aioh.org.au/resources/publications1/publications/occupational-hygiene-monitoring-and-compliance-strategies
https://www.icmm.com/en-gb/health-and-safety/health/health-risk-assessment
https://www.icmm.com/en-gb/health-and-safety/health/health-risk-assessment
AIOH Risk Management Guidebook Page 26 
 
Ignacio, JS & WH Bullock (2006). A Strategy for Assessing and Managing Occupational Exposures, 
Third Edition. American Industrial Hygiene Association (AIHA). https://www.amazon.com/Strategy-
Assessing-Managing-Occupational-Exposures/dp/1931504695 (accessed 7/01/2020). 
IPIECA & IOGP (2006). A roadmap to health risk assessment in the oil and gas industry. 
http://www.ipieca.org/resources/good-practice/health-risk-assessment/ (accessed 7/01/2020). 
IPIECA & IOGP (2019). Health management in the oil and gas industry. 
http://www.ipieca.org/resources/good-practice/health-management-in-the-oil-and-gas-industry/ 
(accessed 7/01/2020). 
Jaycock, MJ, J Lynch & DI Nelson (2000). Risk Assessment Principles for the Industrial Hygienist. 
American Industrial Hygiene Association (AIHA). 
National Academies of Sciences, Engineering & Medicine (2019). Management of Legionella in Water 
Systems. Washington, DC: The National Academies Press. 
https://www.nap.edu/catalog/25474/management-of-legionella-in-water-systems (accessed 
7/01/2020). 
SWA (2013a). Health Monitoring for Exposure to Hazardous Chemicals – Guide for Medical 
Practitioners. Safe Work Australia, Canberra. https://www.safeworkaustralia.gov.au/doc/health-
monitoring-exposure-hazardous-chemicals-guide-medical-practitioners (accessed 7/01/2020). 
SWA (2013b). Guide on exposure to solar ultraviolet radiation (UVR). Safe Work Australia, Canberra. 
https://www.safeworkaustralia.gov.au/doc/guide-exposure-solar-ultraviolet-radiation-uvr (accessed 
7/01/2020). 
SWA (2015a). Guide to managing risks of exposure to hand arm vibration.Safe Work Australia, 
Canberra. https://www.safeworkaustralia.gov.au/collection/workplace-vibration-guidance-material 
(accessed 7/01/2020). 
SWA (2015b). Guide to managing risks of exposure to whole body vibration. Safe Work Australia, 
Canberra. https://www.safeworkaustralia.gov.au/collection/workplace-vibration-guidance-material 
(accessed 7/01/2020). 
SWA (2018a). Model Code of Practice: How to manage work health and safety risks. Safe Work 
Australia, Canberra. https://www.safeworkaustralia.gov.au/doc/model-code-practice-how-manage-
work-health-and-safety-risks (accessed 7/01/2020). 
SWA (2018b). Model Code of Practice: Hazardous manual tasks. Safe Work Australia, Canberra. 
https://www.safeworkaustralia.gov.au/doc/model-code-practice-hazardous-manual-tasks (accessed 
7/01/2020). 
SWA (2019). Workplace Exposure Standards for Airborne Contaminants. Safe Work Australia, 
Canberra. December 2019. https://www.safeworkaustralia.gov.au/doc/workplace-exposure-
standards-airborne-contaminants (accessed 7/01/2020). 
Takala J, P Hämäläinen, KL Saarela, LY Yun, K Manickam, TW Jin, P Heng, C Tjong, LG Kheng, S Lim & 
GS Lin (2014). Global estimates of the burden of injury and illness at work in 2012. J Occup Environ 
https://www.amazon.com/Strategy-Assessing-Managing-Occupational-Exposures/dp/1931504695
https://www.amazon.com/Strategy-Assessing-Managing-Occupational-Exposures/dp/1931504695
http://www.ipieca.org/resources/good-practice/health-risk-assessment/
http://www.ipieca.org/resources/good-practice/health-management-in-the-oil-and-gas-industry/
https://www.nap.edu/catalog/25474/management-of-legionella-in-water-systems
https://www.safeworkaustralia.gov.au/doc/health-monitoring-exposure-hazardous-chemicals-guide-medical-practitioners
https://www.safeworkaustralia.gov.au/doc/health-monitoring-exposure-hazardous-chemicals-guide-medical-practitioners
https://www.safeworkaustralia.gov.au/doc/guide-exposure-solar-ultraviolet-radiation-uvr
https://www.safeworkaustralia.gov.au/collection/workplace-vibration-guidance-material
https://www.safeworkaustralia.gov.au/collection/workplace-vibration-guidance-material
https://www.safeworkaustralia.gov.au/doc/model-code-practice-how-manage-work-health-and-safety-risks
https://www.safeworkaustralia.gov.au/doc/model-code-practice-how-manage-work-health-and-safety-risks
https://www.safeworkaustralia.gov.au/doc/model-code-practice-hazardous-manual-tasks
https://www.safeworkaustralia.gov.au/doc/workplace-exposure-standards-airborne-contaminants
https://www.safeworkaustralia.gov.au/doc/workplace-exposure-standards-airborne-contaminants
AIOH Risk Management Guidebook Page 27 
 
Hyg, 11(5); pp 326-337. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4003859/ (accessed 
7/01/2020). 
WHO (2007). Legionella and the prevention of legionellosis. Edited by: J Bartram, Y Chartier, JV Lee, 
K Pond and S Surman-Lee. World Health Organization (WHO). 
https://www.who.int/water_sanitation_health/emerging/legionella.pdf (accessed 7/01/2020). 
 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4003859/
https://www.who.int/water_sanitation_health/emerging/legionella.pdf
AIOH Risk Management Guidebook Page 28 
 
Appendix 1: Health Hazard Identification (HHI) Form 
 
Company: SEG / Department: 
Worksite / Location: HHI No.: Date: 
Assessment Team Members: Insert name, occupation and signature 
1. 
2. 
3. 
4. 
SEG / Job / 
Location / 
Equipment 
Number per 
shift 
Basic 
hours 
Work pattern 
 
 
 
Description of job / SEG and tasks (Note: Include a broad-brush description to give an overview of the job 
and tasks involved) 
 
 
 
 
 
 
Job type / SEG Hazardous Agent Inventory 
Agent Employee health checks Monitoring OES 8hr 
TWA/15 min 
STEL/Other 
 
 
 
 
 
 
 
 
Agent Tasks with exposure risk identified Work area 
 
 
 
 
 
 
 
 
 
 
AIOH Risk Management Guidebook Page 29 
 
Appendix 2: Health Exposure Consequence Rating for Hazards 
The consequence scale is as follows: 
5 Severe – can potentially cause fatality, cancer or reproductive / genetic health effects to one 
or more people resulting from chemical, physical or biological agent exposures. 
4 Major – can potentially cause irreversible health effects or disabling illness to one or more 
people resulting from chemical, physical or biological agent exposures. 
3 Moderate - can cause severe reversible health effects of concern - could result in a lost time 
illness. 
2 Minor - can cause reversible harm to health that could typically result in a medical treatment 
with no lost time. 
1 Negligible - can cause negligible reversible harm to health (e.g. temporary discomfort), 
requiring first aid treatment at most. 
Note that a rating of 5 is considered the most serious hazard, while a rating of 1 is least hazardous. 
A general description of the health effects for each rating on the consequences scale is provided 
below. Also, for chemical exposures, refer to the table of GHS / non-GHS Hazard Statements. 
5. Severe – Potential fatality, cancer or reproductive / genetic health effects to one or more 
people resulting from chemical, physical or biological agent exposures. 
GHS Hazard Statements Non-GHS Risk Phrases GHS / Non-GHS Description 
H304 R65 May be fatal if swallowed and enters airways 
H310 R27 Fatal in contact with skin 
H330 R23; R26 Fatal if inhaled 
H340 R46 May cause genetic defects 
H350 R45 May cause cancer 
H360 R60‐63 May damage fertility or the unborn child 
This category should include known carcinogens, teratogens, mutagens & reproductive toxicants. 
Some examples are as follows: 
Occupational carcinogens include about 300–350 substances. They include chemical substances 
(see list below), physical hazards such as ultraviolet radiation (UVR) and ionising radiation, and 
biological hazards such as viruses (Hepatitis B and C, Epstein-Barr). The most common cancers 
resulting from these exposures are cancers of the lung, bladder, skin, mesothelium, liver, 
haematopoietic tissue, bone and soft connective tissue. Agents in IARC classifications are typically 
AIOH Risk Management Guidebook Page 30 
 
Class 1 and 2A11 and in the GHS are Category 1.12 Some potential occupational carcinogens in 
industry are as follows: 
• Arsenic 
• Asbestos 
• Benzene or its toxic homologues 
• Beryllium and beryllium compounds 
• Cadmium and compounds 
• Chromium (VI) and compounds 
• Coal tars and coal-tar pitches; soot 
• Diesel exhaust particulate (DPM) 
• Ionising radiation 
• Nickel and compounds 
• Radon and its decay products 
• Silica, respirable crystalline 
• Sulphuric acid mist 
• Talc containing asbestiform fibres 
• Tar, pitch, bitumen, mineral oil, anthracene, or the compounds, products or residues of these 
substances 
• Ultraviolet radiation 
• Uranium and compounds 
• Wood dust (hard wood) 
Reproductive hazards in the workplace include around 200–300 chemicals known to be mutagenic 
or carcinogenic. The reported adverse effects include infertility, spontaneous abortion, foetal death, 
teratogenesis, foetal cancer, fetotoxicity and retarded development of the foetus or newborn. 
Ionising radiation, numerous organic solvents and toxic metals (e.g. lead), many biological agents 
(such as certain bacteria, viruses and zoonoses), are associated with an increased risk of 
reproductive disorders. Both male and female workers may be affected by these hazards. 
It may also include substances that cause mutagenesis; asphyxia; anoxia/hypoxia; haematologic 
disturbances [e.g. anaemia, methemoglobinemia]; and life-threatening respiratory sensitisation. 
It should also include acute / short-term high-risk effects associated with substances such as: 
• Hydrogen cyanide (HCN); 
• Carbon monoxide (CO); and 
• Hydrogen sulphide (H2S). 
 
 
11 Refer to the IARC Monographs on the Identification of CarcinogenicHazard to Humans. International 
Agency for Research on Cancer. https://monographs.iarc.fr/monographs-and-supplements-available-online/ 
(accessed 7/01/2020). 
12 Refer to the Safe Work Australia section on carcinogens, which has adopted the GHS classification system. 
https://www.safeworkaustralia.gov.au/carcinogens (accessed 7/01/2020). 
https://monographs.iarc.fr/monographs-and-supplements-available-online/
https://www.safeworkaustralia.gov.au/carcinogens
AIOH Risk Management Guidebook Page 31 
 
4. Major – Potential irreversible health effects or disabling illness to one or more persons 
resulting from chemical, physical or biological agent exposures. 
GHS Hazard 
Statements 
Non-GHS Risk Phrases GHS / Non-GHS Description 
H341 R68 Suspected of causing genetic defects 
H351 R40 Suspected of causing cancer 
H361 R62-63 Suspected of damaging fertility or the 
unborn child 
H370 R39/23; R39/24; R39/25; 
R39/26; R39/27; R39/28 
Causes damage to organs 
H372 R48/25; R48/24; R48/23 Causes damage to organs through 
prolonged or repeated exposure 
AUH029 R29 Contact with water liberates toxic gas 
AUH070 Toxic by eye contact 
AUH071 Corrosive to the respiratory tract 
This category should include suspected carcinogens (IARC Class 2B & GHS Category 2), mutagens, 
teratogens and reproductive toxicants and progressive chronic conditions with a known cause. 
Some examples are as follows: 
• Noise induced hearing loss (NIHL); 
• Dusts (e.g. siderosis, bronchopulmonary diseases caused by hard metal dust, chronic obstructive 
pulmonary diseases). Also includes non-asbestos fibrous silicates with IARC 2B classification (e.g. 
refractory ceramic fibres); 
• Fume (e.g. mercury, fluorine, carbon disulphide, thallium); 
• Occupational asthma; may be caused by exposure to various organic dusts, microorganisms, 
bacteria, fungi and moulds, and several chemicals; 
• Skin diseases; allergic skin diseases are some of the most prevalent occupational diseases. 
However, physical, chemical or biological agents may cause skin diseases; 
• Infectious diseases that can result in progressive chronic disease (e.g. HIV/AIDS, hepatitis B and 
hepatitis C viruses); and 
• Other agents that cause permanent central nervous system damage; pulmonary oedema; 
cardiac arrhythmia; chronic/long-term organ toxicity (e.g. cumulative lung damage). 
 
AIOH Risk Management Guidebook Page 32 
 
3. Moderate - Severe, reversible health effects of concern. 
GHS Hazard 
Statements 
Non-GHS Risk 
Phrases 
GHS / Non-GHS Description 
H311 R24 Toxic in contact with skin 
H314 R34/35 Causes severe skin burns and eye damage 
H318 R41 Causes serious eye damage 
H319 R36 Causes serious eye irritation 
H331 R23 Toxic if inhaled 
H362 R64 May cause harm to breast-fed children 
H371 R68/20; R68/21; 
R68/22 
May cause damage to organ 
H373 R48/20; R48/21; 
R48/22 
May cause damage to organs through prolonged or 
repeated exposure 
 
This category might include acute / short-term effects associated with: 
• Extreme temperature effects (e.g. sunstroke, frostbite); 
• Sulphur dioxide (SO2); 
• Ammonia (NH3); 
• Solvents; 
• Ozone; 
• Phosgene; 
• Mineral acids and effects on teeth; and 
• Substances that cause elevated irritation of eyes, nose, throat or skin. 
Or other progressive chronic conditions with a known cause, such as: 
• Musculoskeletal effects - disorder of muscles, tendons, bones and joints (e.g. back strain and 
over-use syndrome). Specific work activities or work environments can contribute to 
musculoskeletal diseases where particular risk factors are present (e.g. rapid or repetitive 
motion, forceful exertion, awkward postures, vibration). 
• Vibration; disorder of muscles, tendons, bones, joints, peripheral blood vessels or peripheral 
nerves; 
• Nervous system effects (e.g. cholinesterase inhibition) other than narcosis. 
Or other infectious diseases (e.g. tuberculosis infections). 
May result in a lost time incident. 
 
AIOH Risk Management Guidebook Page 33 
 
2. Minor - Reversible harm to health. 
GHS Hazard 
Statements 
Non-GHS Risk 
Phrases 
GHS / Non-GHS Description 
H305 May be harmful if swallowed and enters 
airways 
H312 R21 Harmful in contact with skin 
H315 R38 Causes skin irritation 
H317 R43 May cause an allergic skin reaction 
H320 Causes eye irritation 
H332 R20 Harmful if inhaled 
H333 May be harmful if inhaled 
H335 R37 May cause respiratory irritation 
H336 R67 May cause drowsiness or dizziness 
 
This category might include conditions such as: 
• Travel effects (e.g. jet lag); 
• Stress (psychological; e.g. work carried out at risk of violence); 
• Sunburn; 
• Narcosis; and 
• Moderate irritation of eyes, nose, throat and/or skin. 
May require medical treatment. 
1. Negligible - Negligible reversible harm to health (temporary discomfort). 
GHS Hazard Statements Non-GHS Risk Phrases GHS / Non-GHS Description 
H313 May be harmful in contact with skin 
H316 Causes mild skin irritation 
 
This category might include conditions such as: 
• Minor irritations of eyes, throat, nose and or skin; 
• Offensive smells; 
• Nuisance noises; 
• Minor unaccustomed muscular discomfort; 
• Minor unaccustomed cardiovascular discomfort (aerobically unfit); and 
• Minor headaches. 
Will only require first aid treatment at worst. 
 
AIOH Risk Management Guidebook Page 34 
 
Table 2.1: Consequence rating for specific chemical hazards 
NB These ratings do not take into account additive effects, nor any other combined effects that 
exposure to more than one chemical may cause 
Agent Health impact Consequence 
scale rating 
Aluminium pot room 
aerosols; 
Occupational asthma 4 
Ammonia Eye damage, upper respiratory tract (URT) irritation 3 
Arsenic Carcinogen 5 
Asbestos Carcinogen 5 
Benzene Carcinogen 5 
Beryllium and beryllium 
compounds 
Carcinogen 5 
Cadmium and 
compounds 
Carcinogen 5 
Carbon disulphide Peripheral nervous system impairment 4 
Carbon monoxide Chemical asphyxiant, carboxyhaemoglobin anaemia 5 
Ceramic fibres, 
refractory 
Irritation, pulmonary fibrosis, carcinogen 1 to 5 
Chromium (VI) and 
compounds 
Carcinogen 5 
Coal tar pitch volatiles Carcinogen 5 
Cotton dust Asthma 4 
Diesel exhaust 
particulate 
Carcinogen 5 
Ethylene oxide 
Central nervous system (CNS) impairment, 
carcinogen, 
3 to 5 
Fluorine URT, eye & skin irritation 4 
Hydrogen cyanide Chemical asphyxiant 5 
Hydrogen sulphide Chemical asphyxiant 5 
Iron URT & skin irritation 2 
Isocyanates Occupational asthma 4 
Lead Reproductive effect 5 
Mercury CNS impairment 4 
AIOH Risk Management Guidebook Page 35 
 
Table 2.1: Consequence rating for specific chemical hazards 
NB These ratings do not take into account additive effects, nor any other combined effects that 
exposure to more than one chemical may cause 
Agent Health impact Consequence 
scale rating 
Nickel and compounds Pneumoconiosis, carcinogen 4 to 5 
Oil mist, mineral LRT irritation, suspected carcinogen 1 to 5 
Organo-phosphorus 
pesticides 
CNS dysfunction 3 
Ozone Respiratory tract irritation 3 
Phosgene URT irritation, emphysema 3 
Radon and its decay 
products 
Carcinogen 5 
Silica, respirable 
crystalline 
Silicosis, carcinogen 4 to 5 
Solvents CNS depression 3 
Sulphur dioxide URT & LRT irritation 3 
Sulphuric acid mist Suspected carcinogen 5 
Talc containing 
asbestos fibres 
Carcinogen 5 
Thallium Alopecia 4 
Uranium and 
compounds 
Carcinogen 5 
Wood dust (oak, beech) Carcinogen 5 
Wood dust (western 
red cedar) 
Asthma 4 
 
 
AIOH Risk Management Guidebook Page 36 
 
Table 2.2: Consequence rating for specific physical hazards 
NB These ratings do not take into account additive effects, nor any other combined effects that 
exposure to more than one agent may cause 
Agent Health impact Consequence scale 
rating 
Cold temperatures 
Hypothermia,chilblains, 
frostbite 
2 
Heat (heat cramps, prickly heat, 
dehydration) 
Hyperthermia 2 
Ionising radiation Carcinogen 5 
Musculoskeletal injury / disorder Progressive chronic condition 3 
Noise induced hearing loss Progressive chronic condition 4 
Temperature – extreme heat or cold Sunstroke, frostbite 3 
Travel – long distance Jet lag 2 
Ultraviolet radiation Carcinogen 5 
UV radiation Sunburn, carcinogen 2 to 5 
Vibration-induced disorders Progressive chronic condition 3 
 
Table 2.3: Consequence rating for specific biological hazards 
NB These ratings do not take into account additive effects, nor any other combined effects that 
exposure to more than one agent may cause 
Agent Health impact Consequence scale 
rating 
Anthrax Pulmonary disease often fatal 5 
Avian bird flu Severe pulmonary disease with high mortality rate 5 
Bacteria Allergic response 4 
Falciparum malaria 
Haematological disease with severe systemic 
symptoms 
5 
Fungi Allergic response 4 
Hepatitis A virus Inflammatory condition of the liver 3 
Hepatitis B & C 
virus 
Severe liver disease 4 
HIV/AIDS 
Compromised immune system resulting in severe 
opportunistic infections 
5 
AIOH Risk Management Guidebook Page 37 
 
Table 2.3: Consequence rating for specific biological hazards 
NB These ratings do not take into account additive effects, nor any other combined effects that 
exposure to more than one agent may cause 
Agent Health impact Consequence scale 
rating 
Legionella bacteria Acute lung disease 4 
Leptospirosis Renal failure 5 
Malaria Severe infectious illness 5 
Mould Allergic response 4 
Q-fever Acute febrile illness 3 
Tuberculosis 
infections 
Chronic granulomatous infection of the lungs 3 
Appendix 3: Health Exposure Likelihood Rating Descriptors 
Likelihood is expressed in terms of the following five-point scale: 
A Almost certain regular contact with the potential hazard at very high levels 
B Likely periodic contact with the potential hazard at very high levels or regular 
contact with the potential hazard at high levels 
C Possible periodic contact with the potential hazard at high levels or regular 
contact with the potential hazard at moderate levels 
D Unlikely periodic contact with the potential hazard at moderate levels or regular 
contact with the potential hazard at low levels 
E Rare periodic contact with the potential hazard at low levels 
The following tables provide exposure descriptors for each of the five points on the likelihood scale 
for a number of type of hazards: 
• Biological; 
• Chemical; 
• Ergonomic (including vibration); 
• Noise; 
• Radiation; and 
• Thermal. 
Different descriptors are given for each type of hazard. The descriptor chosen will depend on the 
amount of quantitative information available but all include a description of both the magnitude and 
the frequency of the exposure. 
AIOH Risk Management Guidebook Page 38 
 
The tables indicate that the exposure described in the second column will result in the likelihood 
measure in the first column. This is the likelihood of the consequence associated with the hazard 
under consideration. 
A rating of “Almost certain” is considered the highest exposure and therefore the highest likelihood 
of the consequence, while a rating of “Rare” is the lowest exposure and therefore the least 
likelihood of the consequence. 
For example, referring to Table 3.1 if the exposure involves “Continuous contact with mist dispersed 
from heavily contaminated water”, this will “almost certainly” cause the consequence of acute, 
possibly fatal, lung disease if the contaminant is Legionella bacteria. 
 
BIOLOGICAL exposure rating descriptors 
Table 3.1: Process water - Qualitative water mist exposure descriptor (also covers 
Legionella) 
5 - Almost 
Certain 
Regular contact with water mist dispersed from very highly contaminated 
water (e.g. from a poorly maintained cooling tower or from sprayed water from 
a contaminated water source or stagnant water that could be entrained in an 
air stream, such as a process water holding pond used for dust suppression) 
4 – Likely Periodic contact with water mist dispersed from very highly contaminated 
water 
Regular contact with water mist dispersed from highly contaminated water 
(e.g. a poorly maintained cooling tower or other contaminated water source or 
stagnant water that could be entrained in an air stream) 
3 – Possible Periodic contact with water mist dispersed from highly contaminated water 
Regular contact with water mist dispersed from moderately contaminated 
water (e.g. an irregularly maintained cooling tower or other moderately 
contaminated water source) 
2 – Unlikely Periodic contact with water mist dispersed from moderately contaminated 
water 
Regular contact with water mist dispersed from treated water (e.g. a regularly 
maintained and clean cooling tower or other clean water source) 
1 - Rare Periodic contact with water mist dispersed from treated and clean water 
 
 
AIOH Risk Management Guidebook Page 39 
 
Table 3.2: Process water – Quantitative water mist exposure descriptor (based on Legionella 
count) 
Refer to ‘Air-handling and water systems of buildings - Microbial control Performance-based 
maintenance of cooling water systems’ (AS/NZS 3666.3, 2011) for more detail on guidance for 
cooling tower remedial action. It is noted that cfu/mL quantitation of Legionella can be highly 
variable, as Legionella resides within a biofilm coating in pipes and distal fixtures. WHO (2007) 
provides examples of microbiological quality monitoring and action level specifications for cooling 
water systems where < 10 cfu/mL is considered acceptable control with no remedial action required 
and > 100 cfu/mL requires implementation of corrective actions. The National Academies of 
Sciences, Engineering & Medicine (2019) note that a Legionella concentration of 50 cfu/mL should 
be considered an “action level”, that is, a concentration high enough to warrant serious concern and 
trigger remediation. A lower action level may be necessary to protect those at higher risk for 
legionellosis, such as hospital patients. They also noted that higher concentrations of Legionella are 
associated with higher disease risk, particularly when greater than 1,000 cfu/mL. 
5 – Almost 
Certain 
Regular contact with water mist containing greater than 1,000 cfu/mL 
Legionella 
4 – Likely Periodic contact with water mist containing greater than 1,000 cfu/mL 
Legionella 
Regular contact with water mist containing less than 1,000 cfu/mL but greater 
than 50 cfu/mL Legionella 
3 – Possible Periodic contact with water mist containing less than 1,000 cfu/mL but greater 
than 50 cfu/mL Legionella 
Regular contact with water mist containing less than 50 cfu/mL but greater 
than 10 cfu/mL Legionella 
2 – Unlikely Periodic contact with water mist containing less than 50 cfu/mL but greater 
than 10 cfu/mL Legionella 
Regular contact with water mist containing less than 10 cfu/mL Legionella 
1 - Rare Periodic contact with water mist containing less than 10 cfu/mL Legionella 
 
 
AIOH Risk Management Guidebook Page 40 
 
Table 3.3: Potable water - Qualitative biological and chemical exposure descriptor 
Refer to ‘Australian Drinking Water Guidelines’ for more detail on guidance for managing the risks 
associated with hazardous biological and chemical contaminants in water.13 
5 – Almost 
Certain 
Exceedance of biological or toxic agent limits occurs more often than once per 
week (52/yr) or there is limited or no monitoring data available and the potable 
water management processes are not well understood 
4 – Likely Exceedance of biological or toxic agent limits occurs more often than once per 
month (12/yr) and up to once per week (52/yr) or there is limited monitoring 
data available and there is some understanding of potable water management 
processes 
3 –Possible Exceedance of biological or toxic agent limits occurs more often than once per 
year and up to once a month (12/yr) or there is at least a year of continuous 
monitoring data available, which has been assessed and there is a reasonable 
understanding of the processes involved 
2 – Unlikely Exceedance of biological or toxic agent limits occurs more often than once 
every five years, up to once per year, or there is five years of collated and 
assessed continuous monitoring data (with at least weekly monitoring during 
seasonal events), and there is a good understanding of the processes involved 
1 - Rare Exceedance of biological or toxic agent limits occurs less than or equal to once 
every five years or there is five years of trended and assessed continuous 
monitoring data with at least daily checking, and the processes involved are 
thoroughly understood 
 
Table 3.4: Vector-borne disease - Qualitative environmental and behavioural factor 
exposure descriptor 
5 – Almost 
Certain 
There is no environmental control of the vector, with people not using personal 
vector repellent (e.g. DEET) or protective clothing, not using an insecticide 
treated net, not taking appropriate prophylactic drug, and having poor 
knowledge of disease symptoms 
4 – Likely There is poor environmental control of the vector, with people using personal 
vector repellent (e.g. DEET) but not protective clothing, using an insecticide 
treated net, but not taking appropriate prophylactic drug, and having poor 
knowledge of disease symptoms 
3 – Possible There is poor environmental control of the vector, with people not using 
personal vector repellent (e.g. DEET) or protective clothing, not using an 
 
13 Australian Drinking Water Guidelines (2011) - Updated November 2018, at Water Quality Australia website - 
https://www.waterquality.gov.au/guidelines/drinking-water 
https://www.waterquality.gov.au/guidelines/drinking-water
AIOH Risk Management Guidebook Page 41 
 
insecticide treated net, but taking appropriate prophylactic drug, and having 
poor knowledge of disease symptoms 
2 – Unlikely There is poor environmental control of the vector, but people are using 
personal vector repellent (e.g. DEET) and protective clothing, using an 
insecticide treated net, taking appropriate prophylactic drug, and have good 
knowledge of disease symptoms 
1 - Rare There is good environmental control of the vector, with people using personal 
vector repellent (e.g. DEET) and protective clothing, using an insecticide 
treated net, taking appropriate prophylactic drug, and having good knowledge 
of disease symptoms 
 
Table 3.5: Food borne pathogens - Qualitative design and behavioural factor exposure 
descriptor 
There are numerous variables to consider when determining food borne pathogens descriptors. 
Refer to the principals of HACCP (Hazard Analysis and Critical Control Points) for more detail on 
guidance for a systematic and preventive food safety management system.14 Facilities designed, 
maintained and managed following the principals of HACCP are defined as being located, 
constructed and maintained according to sanitary requirements. 
5 – Almost 
Certain 
If any 4 of the following items are ticked: 
 Facility is not located, constructed and maintained according to sanitary 
design principles; 
 Suppliers do not have in place effective food safety programs; 
 Cleaning and sanitation procedures are not always followed; 
 Not all personnel follow personal hygiene requirements; 
 Not all raw materials and products are stored under good sanitary and 
environmental conditions (e.g. temperatures); and 
 Not all food is prepared according to good sanitary requirements 
4 – Likely If any 3 of the following items are ticked: 
 Facility is not located, constructed and maintained according to sanitary 
design principles; 
 Suppliers do not have in place effective food safety programs; 
 Cleaning and sanitation procedures are not always followed; 
 Not all personnel follow personal hygiene requirements; 
 Not all raw materials and products are stored under good sanitary and 
environmental conditions (e.g. temperatures); and 
 Not all food is prepared according to good sanitary requirements 
 
14 Food and Agriculture Organization of the United Nations (FAO) ‘Good hygiene practices and HACCP’ website 
- http://www.fao.org/food/food-safety-quality/capacity-development/haccp/en/ (accessed 7/1/2020). 
http://www.fao.org/food/food-safety-quality/capacity-development/haccp/en/
AIOH Risk Management Guidebook Page 42 
 
3 – Possible If any 2 of the following items are ticked: 
 Facility is not located, constructed and maintained according to sanitary 
design principles; 
 Suppliers do not have in place effective food safety programs; 
 Cleaning and sanitation procedures are not always followed; 
 Not all personnel follow personal hygiene requirements; 
 Not all raw materials and products are stored under good sanitary and 
environmental conditions (e.g. temperatures); and 
 Not all food is prepared according to good sanitary requirements 
2 – Unlikely If any 1 of the following items are ticked: 
 Facility is not located, constructed and maintained according to sanitary 
design principles; 
 Suppliers do not have in place effective food safety programs; 
 Cleaning and sanitation procedures are not always followed; 
 Not all personnel follow personal hygiene requirements; 
 Not all raw materials and products are stored under good sanitary and 
environmental conditions (e.g. temperatures); and 
 Not all food is prepared according to good sanitary requirements 
1 - Rare Facility is located, constructed and maintained according to sanitary design 
principles, suppliers have in place effective food safety programs, cleaning and 
sanitation procedures are all followed, all personnel follow personal hygiene 
requirements, all raw materials and products are stored under good sanitary 
and environmental conditions (e.g. temperatures), and all food is prepared 
according to good sanitary requirements 
 
 
AIOH Risk Management Guidebook Page 43 
 
CHEMICAL exposure rating descriptors 
Table 3.6: In-air exposure - Qualitative chemical exposure descriptor 
5 - Almost 
Certain 
Regular contact with the potential hazard at very high concentrations 
4 – Likely 
Periodic contact with the potential hazard at very high concentrations or 
Regular contact with the potential hazard at high concentrations 
3 - Possible 
Periodic contact with the potential hazard at high concentrations or 
Regular contact with the potential hazard at moderate concentrations 
2 - Unlikely 
Periodic contact with the potential hazard at moderate concentrations or 
Regular contact with the potential hazard at low concentrations 
1 – Rare Periodic contact with the potential hazard at low concentrations 
 
Table 3.7: In-air exposure - Quantitative chemical exposure descriptor (based on SEG mean 
8h TWA exposure relative to the OEL15) 
Compares an estimation of the mean of the exposure profile for a SEG relative to the OEL. Possible 
criteria for frequency of air monitoring is included. Adapted from information in Ignacio & Bullock 
(2006). 
5 - Almost 
Certain 
Mean > 10 x TWA-OEL Reduce exposure and monitor weekly 
4 – Likely 
Mean: > TWA-OEL but < 10 x TWA-
OEL 
Monitor monthly until exposure 
reduced 
3 - Possible Mean: 50% - 100% TWA-OEL Monitor half yearly to quarterly 
2 – Unlikely Mean: 10% - 50% TWA-OEL Monitor yearly 
1 - Rare Mean <10% TWA-OEL 
Monitoring not required (Provided 
there is no change to the process, 
material or controls since the last 
survey.) 
NOTE: A TWA-OEL (time-weighted-average occupational exposure limit) is the maximum 
acceptable average concentration of a chemical agent. 
 
 
15 For extended or abnormal shifts longer than 8-h/day or 40h/week, adjust the OEL appropriately (e.g. usingthe AIOH shift adjustment tool) before using in this table. 
https://www.aioh.org.au/member-centre/pdf-links-folder/aioh-position-papers/adjustment-of-workplace-exposure-standards-for-extended-work-shifts-2016
AIOH Risk Management Guidebook Page 44 
 
Table 3.8: In-air exposure - Quantitative chemical exposure descriptor (based on SEG UCL 
8hr TWA16 exposure relative to the OEL) 
Compares an estimation of the 95% upper confidence limit (UCL) for a SEG relative to the OEL. 
Adapted from information in Ignacio & Bullock (2006). 
5 - Almost 
Certain 
>5% exceedance of 10 x OEL (95% UCL > 10 x OEL) 
4 – Likely >5% exceedance of the OEL (95% UCL between 1 and 10 x OEL) 
3 - Possible >5% exceedance of 0.5 x OEL (95% UCL between 0.5 and 1 x OEL) 
2 – Unlikely >5% exceedance of 0.1 x OEL (95% UCL between 0.1 and 0.5 x OEL) 
1 - Rare Little to no exceedance of 0.1 x OEL (95% UCL <0.1 x OEL) 
 
Table 3.9: Dermal exposure - Qualitative chemical exposure descriptor 
5 – Almost 
Certain 
Regular immersion of hands in contaminant or saturation of clothing 
4 – Likely Periodic immersion of hands in contaminant or splashing on clothing or 
Regular visible contamination of skin or clothing 
3 – Possible Periodic visible contamination of skin or clothing 
Regular incidental contact 
2 – Unlikely Periodic incidental contact 
1 - Rare Minimal to no opportunity for visible contamination of skin or clothing 
 
Table 3.10: In-air exposure – Semi-quantitative chemical exposure descriptor (based on 
chemical quantities, volatility / dustiness & ventilation control) 
Uses quantities and volatility or dustiness of the chemicals handled and the ventilation control 
applied. It is based on information from the UK Health and Safety Executive COSHH essentials10. 
 
Amount Dustiness/Volatility Ventilation 
5 - Almost 
Certain 
Large amounts (>1000 L or 
>1000 kg) 
very dusty (fine light powder) 
highly volatile (boiling point <50 ºC) 
Natural 
 
16 For extended or abnormal shifts longer than 8-h/day or 40h/week, adjust the OEL appropriately (e.g. using 
the AIOH shift adjustment tool) before using in this table. 
 
AIOH Risk Management Guidebook Page 45 
 
 
4 – Likely Medium to large amounts 
(>200 L <1000 L or >200 kg 
<1000 kg) 
very dusty (fine light powder) 
highly volatile (boiling point <50 ºC) 
Natural 
 
Large amounts (>1000 L or 
>1000 kg) 
dusty (crystalline/granular solids) 
moderately volatile (e.g. boiling point 
>50 ºC <150 ºC) 
Natural 
 As per ‘Almost Certain’ As per ‘Almost Certain’ Dilution 
3 - Possible Small to medium quantities 
(>20 L <200 L or >20 kg <200 
kg) 
very dusty (fine light powder) 
highly volatile (boiling point <50 ºC) 
Natural 
 Medium to large amounts 
(>200 L <1000 L or >200 kg 
<1000 kg) 
dusty (crystalline/granular solids) 
moderately volatile (e.g. boiling point 
>50 ºC <150 ºC) 
Natural 
 
Large amounts (>1000 L or 
>1000 kg) 
low dusting (e.g. pellet-like solids that 
don't break up) 
low volatility (e.g. boiling point >150 
ºC) 
Natural 
 As per ‘Almost Certain’ As per ‘Almost Certain’ Dilution 
 As per ‘Likely’ As per ‘Likely’ Extraction 
2 - Unlikely 
Small quantities (>1 L <20 L or 
>1 kg <20 kg) 
very dusty (fine light powder) 
highly volatile (boiling point <50 ºC) 
Natural 
 Small to medium quantities 
(>20 L <200 L or >20 kg <200 
kg) 
dusty (crystalline/granular solids) 
moderately volatile (e.g. boiling point 
>50 ºC <150 ºC) 
Natural 
 
Medium to large amounts 
(>200 L <1000 L or >200 kg 
<1000 kg) 
low dusting (e.g. pellet-like solids that 
don't break up) 
low volatility (e.g. boiling point >150 
ºC) material; or 
Natural 
 As per ‘Likely’; or As per ‘Likely’; or Dilution 
 As per ‘Possible’; or As per ‘Possible’; or Extraction 
 
As per ‘Almost Certain’ As per ‘Almost Certain’ 
Fully 
enclosed 
AIOH Risk Management Guidebook Page 46 
 
1 - Rare Trace quantities (<1 L or <1 kg) 
very dusty (fine light powder) 
highly volatile (boiling point <50 ºC) 
Natural 
 
Using small quantities (>1 L 
<20 L or >1 kg <20 kg) 
dusty (crystalline/granular solids) 
moderately volatile (e.g. boiling point 
>50 ºC <150 ºC) 
Natural 
 
Using small to medium 
quantities (>20 L <200 L or >20 
kg <200 kg) 
low dusting (e.g. pellet-like solids that 
don't break up) 
low volatility (e.g. boiling point >150 
ºC) material; or 
Natural 
 As per ‘Unlikely’; or As per ‘Unlikely’; or Dilution 
 As per ‘Possible’; or As per ‘Possible’; or Extraction 
 As per ‘Likely’ As per ‘Likely’ 
Fully 
enclosed 
 
 
ERGONOMIC exposure rating descriptors 
Table 3.11: Musculoskeletal exposure - Qualitative ergonomic exposure descriptor (based 
on descriptive terms for body movement) 
The risk of injury / illness rises with the increasing load or force, frequency, repetition and duration 
of manual handling activity by an employee in a work period. The risk increases when the load is 
located above shoulder height, below mid-thigh height, requires extended reach and requires 
manoeuvring to be placed accurately in position. Load characteristics of dimensions, stability, 
rigidity, predictability, surface texture, temperature, grips and handles should also be considered. 
Refer to ‘Hazardous manual tasks - Code of Practice’ (SWA, 2018b) for more detail on guidance for 
managing the risks associated with hazardous manual tasks and control of the risks of workers being 
affected by musculoskeletal disorders. 
5 – Almost 
Certain 
Continuous or frequently repetitive movement exerting extreme stress on 
muscle groups and / or involving excessive load-forces on muscle groups. 
Movements are contrary to normal musculoskeletal structure. May include 
bending and twisting of body significantly out of natural alignment. 
4 – Likely Infrequent repetitive movement exerting extreme stress on muscle groups and 
/ or involving excessive load-forces on muscle groups. Movements are contrary 
to normal musculoskeletal structure. May include bending and twisting of 
body significantly out of natural alignment. 
AIOH Risk Management Guidebook Page 47 
 
Frequent repetitive movement exerting moderate stress on muscle groups and 
/ or involving moderate load-forces on muscle groups. May include bending 
and twisting of body out of natural alignment. 
Sitting at a computer for extended periods of time or standing still in one 
position for extended periods of time. 
3 – Possible Infrequent repetitive movement exerting moderate stress on muscle groups 
and / or involving moderate load-forces on muscle groups. May include 
bending and twisting of body out of natural alignment. 
Frequent use of muscle groups for movement & control of small, lightweight 
loads or tasks. 
2 – Unlikely Infrequent use of muscle groups for movement & control of small, lightweight 
loads or tasks. 
1 - Rare Natural movements of the body. No exertion or movement of the body out of 
natural alignment required. 
 
Table 3.12: Musculoskeletal exposure - Qualitative ergonomic exposure descriptor (based 
on descriptive terms for loads and adverse factors) 
The ‘Almost Certain’ section lists all those manual handling loads and factors that adversely affect 
the musculoskeletal system. Refer to ‘Hazardous manual tasks - Code of Practice’ (SWA, 2018b) for 
more detail on guidance for managing the risks associated with hazardous manual tasks and control 
of the risks of workers being affected by musculoskeletal disorders. 
5 – Almost 
Certain 
Frequent or excessive handling of heavy or awkward loads; 
 Other factors to consider: difficult to hold loads held away from the front of 
the body; load held above shoulder height; twisting of body; reaching for 
load below mid-thigh height; sideways bending and load handling with one 
hand; long load carrying distances; strenuous pushing or pulling; sudden or 
jerky movements; heavy, large, bulky or awkward load; load difficult to 
grasp;unstable and unpredictable load; intrinsically harmful load; handling 
a person or animal; constraints on posture; rough or slippery floors; 
variation in floor levels; adverse climatic conditions; poor lighting; age; 
pregnancy; physical ability; complexity of task; PPE that hinders movement. 
4 – Likely Infrequent handling of heavy or awkward loads; 
Frequent handling of heavy loads; 
 Other factors to consider: difficult to hold loads held away from the front of 
the body; load held above shoulder height; twisting of body; reaching for 
load below mid-thigh height; sideways bending or load handling with one 
hand; long load carrying distances; strenuous pushing or pulling; sudden or 
jerky movements; heavy, large, bulky or awkward load; load difficult to 
AIOH Risk Management Guidebook Page 48 
 
grasp; unstable or unpredictable load; intrinsically harmful load; handling a 
person or animal; constraints on posture; rough or slippery floors; variation 
in floor levels; adverse climatic conditions; poor lighting; age; pregnancy; 
physical ability; complexity of task; PPE that hinders movement. 
3 – Possible Infrequent handling of heavy loads; 
Frequent handling of moderate loads; 
 Other factors to consider: loads held away from the front of the body; 
working with loads above shoulder height; reaching for load below mid-
thigh height; sideways bending or load handling with one hand; pushing or 
pulling; sudden or jerky movements; large and awkward load; unstable load; 
handling a person or animal; constraints on posture; age; complexity of task. 
2 – Unlikely Infrequent handling of moderate loads; 
Frequent handling of small, lightweight loads; 
 Other factors to consider: loads held close to the front of the body; working 
with loads at waist or chest height; load handling with both hands; no 
pushing or pulling; small easy to move loads; good handles to hold load; 
stable load; no constraints on posture; simple task. 
1 - Rare Infrequent handling of small, lightweight loads; 
 Other factors to consider: waste or chest height close to and in front of the 
body; no repetitive movement; simple task. 
 
Table 3.13: Vibration exposure – Qualitative hand-arm vibration exposure descriptor 
Adapted from information in Faulkner (2003). Refer to ‘Guide to Managing Risks of Exposure to 
Hand-Arm Vibration in Workplaces’ (SWA, 2015a) and UK HSE ‘Vibration at Work’ website17 for more 
detail on guidance for managing the risks associated with HAV. 
5 – Almost 
Certain 
Continuous use of high-risk tools and machinery (pneumatic drills, riveting 
tools, impact wrenches, grinders, electric drills, fettling tools); 
Also: exposure to cold, wet and / or damp working conditions; use of PPE that 
diminishes grip; excessive vibration from floor mounted machinery; poorly 
maintained tools; use of force to hold and operate tool; smoker; medical 
condition (Raynaud’s Disease); and / or no scheduled work breaks. 
4 – Likely Frequent use of high-risk tools and machinery; numbness or tingling after 10 
minutes of continuous use; 
Also: exposure to cold, wet and / or damp working conditions; use of PPE that 
diminishes grip; excessive vibration from floor mounted machinery; poorly 
 
17 UK HSE ‘Vibration at Work’ website - http://www.hse.gov.uk/vibration/index.htm (accessed 7/01/2020). 
http://www.hse.gov.uk/vibration/index.htm
AIOH Risk Management Guidebook Page 49 
 
maintained tools; use of force to hold and operate tool; smoker; and / or 
infrequent work breaks. 
3 – Possible Infrequent use of high-risk tools and machinery; 
Also: use of PPE that diminishes grip; cold and dry working conditions; vibration 
from floor mounted machinery; moderately heavy tools; and / or regular work 
breaks. 
2 – Unlikely Frequent use of light weight and well maintained tools; 
Also: easy to grip tools; minimal vibration from floor mounted machinery; dry 
working conditions; frequent rest breaks. 
1 - Rare Infrequent use of light weight tools; 
Also: well maintained tools; dry, warm work conditions; supported or 
suspended tools not requiring force to hold or operate; non-smoker; young, fit 
and healthy worker. 
 
Table 3.14: Vibration exposure – Quantitative hand-arm vibration exposure descriptor 
(based on SEG mean 8hr TWA exposure) 
There are no OEL’s for hand-arm vibration (HAV) provided in Australia. This descriptor is based on 
an estimate of the mean of the exposure profile for a SEG relative to an OEL derived from European 
Union Directive 2002/44/EC, as adapted from the UK HSE ‘Vibration at Work’ website17. 
5 - Almost 
Certain 
A(8) > 5.0 m/s² rms on a continuous basis; also exposure to cold, wet and 
/ or damp working conditions; use of PPE that diminishes grip; poorly 
maintained tools; use of force to hold and operate tool; smoker; medical 
condition (Raynaud’s Disease); and / or no scheduled work breaks. 
4 - Likely A(8) > 5.0 m/s² rms. 
3 - Possible A(8) > 2.5 but < 5.0 m/s² rms. 
2 - Unlikely A(8) < 2.5 m/s² rms. 
1 - Rare 
A(8) < 2.5 m/s² rms; also well maintained tools; dry, warm work 
conditions; supported or suspended tools not requiring force to hold or 
operate; non-smoker; young, fit and healthy worker. 
 
 
AIOH Risk Management Guidebook Page 50 
 
Table 3.15: Vibration exposure – Qualitative whole-body vibration exposure descriptor 
Refer to ‘Guide to Managing Risks of Exposure to Whole Body Vibration in Workplaces’ (SWA, 2015b) 
and UK HSE ‘Vibration at Work’ website17 for more detail on guidance for managing the risks 
associated with WBV. 
5 - Almost 
Certain 
Continuous or frequent exposure to vibration transmitted via the seat (or 
floor) to the operator where seat bottoms out; 
Also: predisposing back injury; frequent turning of the body; no vehicle 
suspension; no cab suspension; rough & poorly maintained roads; 
infrequent rest breaks; and / or under-inflated tyres. 
4 - Likely Frequent exposure to vibration transmitted via the seat (or floor) to the 
operator where seat bottoms out; 
Also: no vehicle suspension; no cab suspension; rough & poorly 
maintained roads; infrequent rest breaks; and / or under-inflated tyres. 
3 - Possible Infrequent exposure to vibration transmitted via the seat (or floor) to the 
operator where seat bottoms out; 
Also: moderate vehicle suspension; no cab suspension; and / or rough & 
poorly maintained roads. 
2 - Unlikely Frequent to vibration transmitted via the seat (or floor) to the operator 
with good seat suspension; 
Also: good cab and vehicle suspension; well maintained and smooth 
roads; frequent rest breaks. 
1 - Rare Infrequent exposure to vibration transmitted via the seat (or floor) to the 
operator; 
Also: well maintained and smooth roads; good vehicle, cab and seat 
suspension; frequent rest breaks. 
 
Table 3.16: Vibration exposure – Quantitative whole-body vibration exposure descriptor 
(based on SEG mean 8hr TWA exposure) 
There are no OEL’s for whole-body vibration (WBV) provided in Australia. This descriptor is based on 
an estimate of the mean of the exposure profile for a SEG relative to an OEL derived from European 
Union Directive 2002/44/EC, as adapted from the UK HSE ‘Vibration at Work’ website17. AS 2670.1-
2013 ‘Evaluation of human exposure to whole-body vibration Part1: General requirements’, provides 
a graph with a health guidance caution zone for comparison with monitoring data. 
5 - Almost 
Certain 
A(8) > 1.15 m/s2 or eVDV > 21 m/s1.75 on a continuous basis; 
Also: predisposing back injury; frequent turning of the body; and / or 
infrequent rest breaks. 
4 - Likely A(8) > 1.15 m/s2 or eVDV > 21 m/s1.75. 
AIOH Risk Management Guidebook Page 51 
 
3 - Possible A(8) > 0.5 but < 1.15 m/s2 or eVDV > 9.1 but < 21 m/s1.75. 
2 - Unlikely A(8) < 0.5 m/s2 and eVDV < 9.1 m/s1.75. 
1 - Rare 
A(8) < 0.5 m/s2 and eVDV < 9.1 m/s1.75; 
Also: no predisposing back injury; frequent rest breaks. 
 
 
NOISE exposurerating descriptors 
While sound pressure levels provide an estimate of the degree of noise exposure, representative full 
shift personal noise dose (estimate of the mean shift exposure) needs to be determined to 
adequately define the risk of noise induced hearing loss. 
Table 3.17: Noise exposure – Quantitative noise exposure descriptor (Based on sound 
pressure levels) 
5 - Almost 
Certain 
Several areas of workplace > 100 dB(A) (must forcibly shout to be heard) 
4 - Likely 
Several areas of workplace between 90 and 100 dB(A) (must shout to be 
heard) 
3 - Possible 
Several areas of workplace between 85 and 90 dB(A) (must use a raised 
voice to be heard) 
2 - Unlikely Several areas of workplace between 80 and 85 dB(A) 
1 - Rare All areas of workplace < 80 dB(A) 
 
Table 3.18: Noise exposure – Quantitative noise exposure descriptor (Based on SEG mean 
8hr TWA exposure18) 
Compares an estimation of the mean of the exposure profile for a SEG relative to recognised noise 
exposure limit values. 
A - Almost 
Certain 
Mean LA eq, 8hr > 96 dB(A) 
Many L Peak > 140 dB(C) 
B - Likely 
Mean LA eq, 8hr > 85 and < 96 dB(A) 
Any L Peak > 140 dB(C) 
C - Possible Mean LA eq, 8hr > 82 and < 85 dB(A) 
 
18 For shifts longer than 8 hours, normalise noise levels according to the Australian standard before using in 
this table. 
AIOH Risk Management Guidebook Page 52 
 
D - Unlikely Mean LA eq, 8hr > 79 and < 82dB(A) 
E - Rare Mean LA eq, 8hr < 79dB(A) 
 
 
RADIATION exposure rating descriptors 
Table 3.19: Ionising radiation – Quantitative physical exposure descriptor 
Adapted from Australian Radiation Protection and Nuclear Agency (ARPANSA) publications ‘Code of 
Practice and Safety Guide for Radiation Protection and Radioactive Waste Management in Mining 
and Mineral Processing’ (ARPANSA, 2005) and ‘Fundamentals – Protection Against Ionising 
Radiation’ (ARPANSA, 2016). 
Dose limits are designed to protect persons from Deterministic and Stochastic effects. Disease such 
as cancer may be caused by stochastic effects of radiation. 
The risk from radiation is dependent on the accumulated dose over long periods of time. This is 
reflected in the limitation system which specifies averaging periods from 1 to 5-year periods. 
Shorter dose rates are considered important in control and management issues rather than risk. 
5 - Certain Exposure to all sources above natural background radiation resulting in an 
Effective Dose which is greater than 50 mSv over a calendar year. 
4 – Likely Exposure to all sources above natural background radiation resulting in an 
Effective Dose which is greater than 20 mSv per year, averaged over a period of 
5 consecutive calendar years. 
3 – Possible Exposure to all sources above natural background radiation resulting in an 
Effective Dose which is greater than 10 mSv, but less than 20 mSv per year, 
averaged over a period of 5 consecutive calendar years. 
2 – Unlikely Exposure to all sources above natural background radiation resulting in an 
Effective Dose which is greater than 2 mSv, but less than 10 mSv per year, 
averaged over a period of 5 consecutive calendar years. 
1 - Rare Exposure to all sources above natural background radiation resulting in an 
Effective Dose which is less than 2 mSv per calendar year 
 
 
AIOH Risk Management Guidebook Page 53 
 
Table 3.20: UV light - Qualitative physical exposure descriptor 
Adapted from ‘Guide on exposure to solar ultraviolet radiation (UVR)’ (SWA, 2013b) and ‘Ultraviolet 
radiation exposure and dose explained’ from the ARPANSA website19. 
5 - Certain Workers whose skin tans poorly or burns easily doing unprotected outdoor 
work in the sun and / or welding aluminium and / or working at high altitude 
where the UV index is 9-10 
4 – Likely Workers whose skin tans poorly or burns easily doing moderately protected 
outdoor work in the sun where the UV index is 7-8 
3 – Possible Workers whose skin tans well or does not burn easily doing outdoor work in 
the sun while wearing moderately protective clothing where the UV index is 5-
6 
2 – Unlikely Workers whose skin tans well or does not burn easily doing outdoor work in 
the sun while wearing full protective clothing (sunglasses, wide-brim hat, long 
sleeves & trousers) and using sunscreen (SPF >30) where the UV index is 3-4 
1 - Rare Workers whose skin tans well or does not burn easily wearing full protective 
clothing, avoiding the mid-day sun and using sunscreen (SPF >30) where the UV 
index is 0-2 
 
 
THERMAL exposure rating descriptors 
Table 3.21: Heat stress - Qualitative physical exposure descriptor 
There are numerous variables to consider when determining the heat stress descriptors. They may 
fall into the category of task, environment or individual physiological condition, or any combination 
of these. For that reason, the AIOH guidance in this area recommends the use of a basic thermal risk 
assessment (BTRA) which does not require extensive monitoring (Di Corleto et al, 2013). More 
complex methodology such as the Thermal Work Limit (TWL) or the Predicted Heat Strain (PHS) can 
also be utilised for greater accuracy but will require access to additional monitoring data. Examples 
below are only a small selection of possible scenarios and do not include the impact of the use of 
encapsulating PPE (i.e. a Haz mat suit). 
5 - Certain BTRA > 80 - for example: An acclimated untrained worker in the sun wearing 
multiple layer clothing with full PPE (e.g. full face respirator) doing heavy work 
at an apparent temperature of >41˚C in conditions of no wind, poor access to a 
cool rest area and drinking water, and hot surfaces (burn on contact) for more 
than 2 hours at a time. 
 
19 ARPANSA website - https://www.arpansa.gov.au/services/monitoring/ultraviolet-radiation-
monitoring/ultraviolet-radiation-dose/ultraviolet (accessed 7/01/2020). 
https://www.arpansa.gov.au/services/monitoring/ultraviolet-radiation-monitoring/ultraviolet-radiation-dose/ultraviolet
https://www.arpansa.gov.au/services/monitoring/ultraviolet-radiation-monitoring/ultraviolet-radiation-dose/ultraviolet
AIOH Risk Management Guidebook Page 54 
 
4 – Likely BTRA > 60 < 80 - for example: An acclimated, trained worker wearing PPE (e.g. 
rubber half-face respirator) and multiple layer clothing while doing simple 
heavy work at an apparent temperature of > 33 <41˚C in conditions of 
moderate wind, poor access to a cool rest area and drinking water, and for not 
more than 1 hour at a time. 
3 – Possible BTRA > 40 < 60 – for example: An acclimated worker wearing no respirator and 
moderately heavy single layer clothing while doing complex moderate work in 
a part shaded area at an apparent temperature of > 33 <41˚C in conditions of 
moderate wind, poor access to a cool rest area and drinking water, and contact 
with neutral surfaces for more than 30 minutes to 1 hour at a time. 
2 – Unlikely BTRA > 28 < 40 – for example: An acclimated, untrained worker wearing no 
respirator and single layer light clothing while doing simple moderate work in 
the full sun at an apparent temperature of >27 <33˚C in conditions of moderate 
wind, good access to a cool rest area and drinking water, and no hot surfaces 
(contact neutral) for less than 2 hours at a time. 
1 - Rare BTRA< 28 – for example: An acclimated worker wearing no respirator and 
single layer light clothing while doing simple light work at an apparent 
temperature of <27˚C in conditions of wind / good ventilation, good access to a 
cool rest area and drinking water, and no hot surfaces (contact neutral) for less 
than 30 minutes. 
 
 
AIOH Risk Management Guidebook Page 55 
 
Appendix 4: Risk Assessment, Action Identification and Prioritisation 
The following figure provides an example of a consequence and likelihood matrix. Health risk is a 
function of consequence (health effect) and likelihood (exposure). The matrix thereforegives a 
health risk rating for each combination of these. The higher the health risk rating, indicated by four 
bands of risk severity, ‘Low’ (L), ‘Medium’ (M), ‘High’ (H) and ‘Extreme’ (E), the higher the priority for 
action. 
 
Consequence Rating (health effect) 
 1 
Negligible 
2 
Minor 
3 
Moderate 
4 
Major 
5 
Severe 
A 
Almost 
certain 
M H H E E 
B 
Likely 
M M H H E 
C 
Possible 
L M M H H 
D 
Unlikely 
L L M M H 
E 
Rare 
L L L M M 
 
Whether the action needed is control, information gathering, or a combination of the two depends 
on the extent of the potential health risk and the certainty of the exposure assessment, as indicated 
by the figure below. 
H
ea
lt
h
 R
is
k 
R
at
in
g 
E 
Urgent and immediate 
control or mitigation 
needed 
Proactive control / 
mitigation & information 
gathering needed 
Proactive control / 
mitigation & information 
gathering needed 
H 
Proactive control / 
mitigation needed 
Proactive control / 
mitigation & information 
gathering needed 
Proactive control / 
mitigation & information 
gathering needed 
M 
Active monitoring 
needed 
Information gathering 
needed 
Proactive control / 
mitigation & information 
gathering needed 
L No action needed 
Information gathering 
needed 
Information gathering 
needed 
 Certain Uncertain Highly Uncertain 
 Uncertainty Rating 
 
 
Li
ke
lih
o
o
d
 R
at
in
g 
(e
xp
o
su
re
) 
AIOH Risk Management Guidebook Page 56 
Appendix 5: SEG / Location / Equipment / Task Appraisal Form 
Complete for each SEG, location, equipment or task, with exposure risk identified, as there may be more than one hazardous agent per SEG / location / 
equipment / task. 
HHI NO…… : SEG / Location / Equipment / Task Name 
AGENT Exposure Route & Form Existing 
Controls 
(footnote 1) 
Controls 
Effective - 
Y/N 
(footnote 2) 
Frequency of 
Exposure 
Duration of 
Exposure 
Estimated or 
Measured 
Exposure 
Level 
Consequence 
Rating 
(health 
effect) 
(Append 2) 
Likelihood 
Rating 
(exposure) 
(Append 3) 
Health Risk 
(Appendix 4) 
Action 
Required Y/N 
(footnote 3) 
e.g. Lead Breathing; dust & fume in air 
Yes – Type 
D 
N Daily ~ 8 hrs 0.09 mg/m3 5 B Extreme Y - c 
 
 
 
 
 
 
 
1. A. Control measures dependent on adequate plant maintenance to be effective. 
 B. Control measures dependent on activation of a device (e.g. extraction fan) to be effective. 
C. Control measures dependent on correct work practices and supervision to be effective. 
D. Control measures dependent on correct wearing of appropriate personal protective equipment (PPE). 
2. If answer is No, action required will always be Yes. 
3. If answer is No, a conclusion as follows must be reached: 
a - The risk is controlled by engineering standards; or 
b - The risk is mitigated only by the use of PPE or administrative controls. Substitution / engineering controls must be considered and any reasons for their not being adopted documented (Attachment 6). 
If answer is Yes, a conclusion as follows must be reached: 
c - There are insufficient data to make a valid assessment – assign a responsible person and action date to conduct an assessment of the exposure, where exposure was only estimated; or 
d - There is a health risk at current exposures - complete a remedial action table (Appendix 7), using the checklist for control according to the hierarchy of controls (Appendix 6) to determine the control that 
will result in a health risk that is ‘As Low as Reasonably Practicable’ (ALARP). 
 
AIOH Risk Management Guidebook Page 57 
Appendix 6: Checklist for Risk Reduction Controls Form * 
SEG / Location: Task: Agent: HHI No: 
General recommendations: Resp. Person: Action date: 
Further information required? 
Y/N 
Details: Resp Person: Action date: 
Can the agent be 
eliminated? 
Yes No 
If yes, remedial action is elimination. Transfer action to remedial action table, with name of person to action. 
If no, give reasons according to principle of ALARP. 
Can the agent be substituted 
with a less hazardous agent? 
Yes No 
If yes, remedial action is substitution. Transfer action to remedial action table, with name of person to action. 
If no, give reasons according to principle of ALARP. 
Can the agent be isolated to 
reduce the risk? 
Yes No 
If yes, remedial action is isolation. Transfer action to remedial action table, with name of person to action. 
If no, give reasons according to principle of ALARP. 
Can engineering controls be 
used to reduce the risk? 
Yes No 
If yes, remedial action is engineering controls. Transfer action to remedial action table, with name of person to 
action. 
If no, give reasons according to principle of ALARP. 
Can administrative controls 
be used to reduce the risk? 
Yes No 
If yes, remedial action is administrative controls. Transfer action to remedial action table, with name of person to 
action. 
If no, give reasons according to principle of ALARP. 
Can personal protective 
equipment be used to 
reduce the risk (consider 
long term)? 
Yes No 
If yes, remedial action is Personal protective equipment. Transfer action to remedial action table with name of 
person to action. 
If no, repeat the assessment of achieving ALARP starting at the top of the hierarchy of controls. 
Assessment of control options carried out by: 
Approved by: 
Date: 
Date: 
 
* The assessment of the practicability of the control measures to achieve control of risk to ALARP, must be carried out according to the hierarchy of controls. The first control measure in the hierarchy that is 
deemed to be practicable must be the one that is chosen as the remedial action. 
 
AIOH Risk Management Guidebook Page 58 
Appendix 7: Remedial Action Table 
HHI 
No. 
SEG / Job / Location / Task for 
improvement 
 
Hazard 
Risk level 
(see 
Appendix 5) 
Remedial action decided 
(using hierarchy of controls, principle of 
ALARP & Appendix 6) 
Responsible 
person 
Due 
date 
target 
Date 
completed 
Residual 
risk