Each year a number people are killed across Australia and internationally while working in confined spaces.

Confined space related injury or death occurs in a wide range of industries and confined spaces are considered to be high-risk, high-consequence environments. With the addition of chemicals and gases into these places, those risks are magnified.  Many deaths in confined spaces occur because people who are attempting to rescue someone else are neither trained nor equipped to do so. In more than 60% of reported confined space fatalities, the would-be rescuer also loses their life.

What is a confined space?

Confined spaces include spaces such as those in a vat, tank, pit, pipe, duct, flue, oven, chimney, silo, reaction vessel, container, receptacle, underground sewer, well, shaft, trench, tunnel or other similar enclosed or partially enclosed structure, which meet certain conditions.

However, many other types of structures may also meet the definition of a confined space provided in the Regulations.

Some structures may become confined spaces when work that generates atmospheric contaminants is carried out or during their construction, fabrication or subsequent modification.

A confined space is determined by the hazards associated with a set of defined circumstances (restricted entry or exit, hazardous atmospheres or risk of engulfment) and not just by the fact that work is performed in a physically restrictive location. The effect of physical or chemical agents may be exacerbated in a confined space.

The description of a confined space by Australian Workplace Health and Safety legislation is a space that:

  • Is at atmospheric pressure when anyone is in the space; and
  • Is not intended or designed primarily as a workplace; and
  • Could have restricted entry to, or exit from, the place; and
  • Is, or is likely to be entered by a person to work; and
  • At any time, contains, or is likely to contain, any of the following:
    • an atmosphere that has potentially harmful levels of a contaminant;
    • an atmosphere that does not have a safe oxygen level;
    • anything that could cause engulfment

What are the risks of working in confined space?

There are many risks of working in confined spaces including:

  • loss of consciousness, injury or death due to the immediate effects of airborne contaminants
  • fire or explosion from the ignition of flammable contaminants
  • asphyxiation resulting from oxygen deficiency
  • asphyxiation resulting from engulfment by stored material, including grain, sand, flour or fertiliser.

Confined space and the Law

The WHS/ OHS Legislation within Australia imposes a general duty on persons with management control to ensure, so far as is reasonably practicable, that workers and other persons are not exposed to health and safety risks arising from the business or undertaking. The legislation also includes specific obligations on a regarding confined spaces.

This duties extends to Designers, manufacturers and suppliers of plant or structures that include a space that is intended, or is likely to become, a confined space.  This duty requires that the designers, manufacturers and suppliers must eliminate the need for any person to enter a confined space and eliminate the risk of inadvertent entry or, if this is not reasonably practicable, ensure safe means of entry and exit and minimise risks to the health and safety of any person who enters the confined space.

Additional duty holder include Officers, such as company directors, who are required to exercise due diligence to ensure that the business or undertaking complies with the WHS Act and Regulations. As well as to ensure that the appropriate resources and processes to eliminate or minimise risks that arise from entry into confined spaces.

Workers must take reasonable care for their own health and safety and that their work does not adversely affect the health and safety of other persons. Workers must comply with any reasonable instructions given relating to confined space entry permits, risk control measures and emergency procedures, and should carry out work in a confined space in accordance with any relevant information and training provided to them.

The OHS / WHS legislation also set out requirements for specific controls measures including communication and safety monitoring, signs, isolation of connected plant and services, and controls to maintain a safe atmosphere within the confined space.

Manage the risks

The most important step in the risk management process involves controlling risks by eliminating them so far as is reasonably practicable, or if that is not possible, by minimising the risks so far as is reasonably practicable

If entering a confined space cannot be avoided, then a safe system for working inside the space must be implemented. Using the risk management process of identifying, assessing and controlling the hazards of working in a confined space should be adopted in order to ensure that the risks are minimised.

The identified hazards will dictate what controls are needed to minimise any risk associated with work in the confined space. The following item must be considered:

  • The nature of the space
  • The concentration of oxygen or airborne contaminants
  • The work and work method
  • Emergency procedures


By: Andrew Angelides