Certificate IV OHS – Glossary of Common OHS Terms

Developing a glossary of of commonly used OHS terms while attending the Certificate IV in OHS is a useful way to ensure that you have the basic terminology correct.

You should have begun your glossary when completing the unit of competency BSBOHS403 Identify hazards and assess OHS risk. We strongly recommend that you add to your glossary 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 Glossary of terms before going any further. When they are first used, glossary terms are indicated in the learning guide with an asterisk (*).

The definitions used in the glossary are taken from the Glossary of Basic OHS Terms complied by Safe Work Australia.

Change management

Making changes in a planned and systematic way to implement new methods and systems within an organisation.

Organisational and process change is a time when safety systems become vulnerable. Planning and monitoring processes need to ensure that when implementing change, new hazards are not created and existing control measures are not breached.

Code of practice

Gives practical guidance on how to comply with legal obligations. Codes of practice may be developed by legislators or industries. They are not mandatory in that a person cannot be prosecuted simply for failing to comply with a code of practice. However, they may be used as evidence in legal proceedings. Therefore, a code of practice should be followed where it is relevant and able to be implemented, unless there is an equal or better way of achieving compliance with legal obligations.

Exposure standard

A quantitative guideline, or level, set for concentrations of workplace contaminants, or physical agents, to which, according to current knowledge, most workers may be exposed without impairment to health or undue discomfort.

Fail-to-safe (Fail-safe)

Design feature of equipment that ensures any failure or defect, or another factor such as loss of power, results in the equipment being left in a safe condition.

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).


Usually used in reference to machine control or guarding where a device interacts with another mechanism to govern operations; eg an interlocked device that will prevent the machine from operating unless the guard is in place.

Lag indicator

Safety performance measure that assesses how successfully a workplace is developing or improving OHS by measuring outcomes, such as numbers or frequency of injuries or claims costs. As changes to these measures usually take considerable time (or ‘lag’) behind the implementation of any improvement strategy they are termed lag indicators.

Lag indicators are usually measures of loss and may also be called ’negative performance indicators’.

Lead indicator

Safety performance measure that assesses how successfully a workplace is developing or improving OHS by measuring the activities that drive or ‘lead’ the safety performance rather than examining the outputs. The results of such activities appear earlier in time to the ‘lag’ or outcome measures. They may be either:

  • a quantitative indicator that can be counted or measured and is described numerically (for example, number of safety audits conducted); or
  • a qualitative indicator that describes or assesses a quality or behaviour (such as rating of management commitment to achieving ‘best practice’ in OHS).

Also referred to as a ‘positive performance indicator’.

Personal Protective Equipment (PPE)

Equipment designed to be worn by a person to provide protection from hazards, by providing a physical barrier between the person and the hazard and may include:

  • head protection
  • face and eye protection
  • respiratory protection
  • hearing protection
  • hand protection
  • clothing and footwear.

Due to inherent design limitations of the equipment and the scope for wearers not to use or to use such equipment inappropriately, personal protective equipment is considered the least satisfactory control measure.

Safe design

A design process that generates options to eliminate hazards, or minimise potential risk to the health and safety of those who make the product and those that use it, by involving decision makers and considering OHS risks throughout the life cycle of the designed product. Safe design generally provides for the minimisation of risk through engineering rather than reliance on human behaviour.


An example or benchmark that defines the minimum acceptable level. Those relevant to OHS include:

  • OHS regulations and standards developed by OHS regulators
  • national standards (Safe Work Australia)
  • Australian standards
  • International standards
  • industry standards
  • codes of practice
  • exposure standards
  • guidance notes.

Unless incorporated by reference in legislation, the various standards, codes and guidance notes are optional only and need not be followed. However, they do form part of the body of knowledge by which what is reasonably practicable can be measured.

Read More OHS Terms

LMIT delivers the Certificate IV in OHS and the Diploma in Occupational Health & Safety Completely Online in Sydney, Melbourne, Brisbane, Perth, Adelaide and Canberra.  The Advanced Diploma in OHS is also available via RPL only.

Published by: LMIT

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