Cert IV OHS/WHS – Glossary of Common OHS Terms

Glossary of Common OHS/WHS Terminology

When you enroll in the Certificate IV in OHS or WHS with LMIT, you’ll be asked to develop and study a glossary of safety industry related terms.

This document is a useful way to ensure that you have the basic terminology correct. We strongly recommend that you develop your own glossary and add to it throughout this unit and the rest of your study.


Some terms relevant to this unit are defined below. Make sure that you are familiar with the smaller Glossary of OHS terms before going any further. When they are first used, glossary terms are indicated in the learning guide with an asterisk (*).

ALARP (As Low As Reasonably Practicable)

A basic concept where risks are kept as low as is ‘reasonably’ practicable where reasonable is determined taking account of social, technical, economic and public policy factors.

ALARP is not an exposure limit but a best practice approach that has the objective of attaining exposure levels as low as possible.


The injury, ill-health or damage resulting from an event, or sequence of events, which may be expressed quantitatively or qualitatively. There may be a range of possible consequences for a specific event or scenario.


A process of seeking information or the informed opinions from one or more people before making a decision. It is important that the process includes those who may affect the outcomes or be affected by the decisions made; but may also include specialist sources. Consultation does not necessarily mean reaching agreement.

Due diligence

The taking of all reasonable precautions in the circumstances to protect the health and safety of employees and others who may be affected by actions or omissions of the individual or corporation.


The point in time when a particular set of circumstances occur that result in loss of control of a hazard.


A source of potential harm in terms of human injury, ill-heath, damage to property, the environment or a combination of these.

A source of potentially damaging energy.

Hazard identification

The process of identifying sources of harm.

Hazards of long latency

Sources of harm such as chemicals, noise, radiation and psychosocial factors that may result in illnesses and other risks to health; but for which the appearance of signs and symptoms of ill-health take a long time to be expressed.

Hierarchy of control

The priority order in which hazard and risk controls should be considered, with the eventual outcome often being a combination of measures. The prime emphasis is on:

  • elimination
  • and where this is not practicable, minimisation of risk by:
  • substitution
  • engineering controls, including isolating the hazard from personnel then, when these options have been implemented as far as is practicable
  • administrative controls (eg procedures, training)
  • personal protective equipment (PPE).


An event that has caused or has the potential to cause injury, ill-health or damage. (Note that ‘incident’ is the preferred term rather than ‘accident’).

Refer also to ‘occurrence’.

Job Safety Analysis (JSA)

Process of breaking a task down into its key components and examining the hazards of each component to identify the required controls. The output of a JSA can be used in developing written job instructions.

Similar processes may have a number of terms such as HIRA (Hazard Identification & Risk Assessment) or JSEA (Job Safety Environmental Analysis).

Key personnel

People involved in OHS decision-making or those who are affected by OHS decisions.


A colloquial term for ‘probability’. When related to risk it is the probability of the stated consequence occurring, not the likelihood of the hazard or the particular scenario.

Likelihood is affected by how often and how long the person (or structure etc) is exposed to the hazard and the reliability of the controls in place.

Near miss

A potential or actual loss of control of a hazard that does not result in injury or damage (use of this term is decreasing in favour or either ‘incident’ or ‘occurrence’).


An alignment chart arranged so that the value of a variable can be found without calculation from the value of one or two other variables that are known.


Process(es) that give(s) rise to damage, injury or ill-health.

Policies and procedures

Documents that describe an approach and method for undertaking certain activities or processes. Those relevant to OHS may include:

  • hazard and incident reporting, OHS communication, consultation, issue resolution and risk management;
  • standard operating procedures, work instructions;
  • operators’ manuals;
  • employee and contractor handbooks;
  • job/task statements;
  • documents describing how tasks, projects, inspections, jobs and processes are to be undertaken;
  • quality system documentation; and
  • purchasing and contracting procedures.


The potential for unwanted, negative consequences of an event.

Risk assessment

A process to develop an understanding of the hazard and its associated risk involving analysing a hazard to:

  • identify factors influencing the risk and the range of potential consequences;
  • evaluate the effectiveness of existing controls;
  • estimate the likelihood of the consequence, considering exposure and hazard level;
  • and combining these in some way to obtain a level of risk or to prioritise the risk for action.


A process of rating risks according to their severity and likelihood to determine the priority for treatment or control of risks. Also known as ‘prioritisation’. Risk-ranking processes range from quantitative to highly subjective.

Risk register

A document detailing:

  • a list of hazards, their location and people exposed;
  • a range of possible scenarios or circumstances under which these hazards may cause injury or damage;
  • nature of injury or damage caused;
  • the results of the risk assessment; and
  • (may also include) possible control measures and dates for implementation.

Sometimes called a ‘Hazard Register’, but this is a narrow term implying the inclusion of only limited information relating to the sources of risk, rather than the consequences and control measures.

Root cause

Condition or circumstance that leads to an event which is identified by following the chain of causation back to the most distant cause that is controllable.


An often misused term as no activity or environment can be 100 per cent risk free. Generally taken to mean that the level of risk is as low as is reasonably practicable, does not breach any OHS legislation, is equitable and has the informed approval of those exposed to the risk.


Those people or organisations who may be affected by, or perceive themselves to be affected by, an activity or decision. In workplace OHS, stakeholders include:

  • managers;
  • supervisors;
  • health and safety and other employee representatives;
  • OHS committees;
  • employees and contractors; and

Read More OHS Terms

LMIT delivers the Certificate IV in OHS and the Diploma in Occupational Health & Safety Completely Online.  The Advanced Diploma in OHS is also available via RPL only.

Published by: LMIT

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