Confined Spaces & Poorly Ventilated Areas

Confined spaces and poorly ventilated areas can be found in many workplaces. Incidents in such areas have resulted in serious injury, death and sometimes multiple fatalities.

Some of the hazards associated with entry and work in a confined space include: 

  • Hazardous substances and harmful atmospheric contaminants (causing dangerous fumes)
  • Flammable contaminants (potentially causing fire and leading to burns and/or suffocation)
  • Unsafe oxygen levels (suffocation)
  • Engulfment
  • Other hazards including mechanical, physical and biological

What you should do if you are concerned about entry or work in confined spaces or poorly ventilated spaces:

  • If you or the members of your designated work group are unsure about the dangers of a confined space or poorly ventilated area, advise them not to enter the space;
  • Go immediately to your employer (or employer's rep) and advise them of this;
  • Request that the employer, in consultation with you, undertake a hazard identification of the space;
  • According to the outcome of the hazard identification, ensure that the appropriate steps are taken to undertake risk assessment and control of the hazard.

Remember that if the space is found to be a "confined space" under the definition of Part 3.4 of the Occupational Health and Safety Regulations, the employer has some very specific duties. If the space is not a "confined space", but is poorly ventilated, it is still covered under Section 21 of the Occupational Health and Safety Act, 2004.

What is a "confined space"?

Confined spaces can be found in many workplaces. A confined space is determined by the hazards associated with a particular set of circumstances (restricted entry or exit, hazardous atmospheres or risk of engulfment). Therefore, a confined space exists when specific factors are present at the same time, and is not simply defined a confined space because work is performed in a physically restrictive location. (For the full regulatory definition of a confined space see the summary of Part 3.4 (Confined Spaces) of the Victorian Occupational Health and Safety Regulations, 2017)

Under the regulations the employer has certain duties with relation to confined spaces:

  • To consult the OHS rep/s when undertaking hazard identification, risk assessment or control of risk processes;
  • To undertake hazard identification;
  • To undertake risk control and record this (one identification and risk control can be done for a "class" of confined spaces);
  • To ensure that any risk associated with work in a confined space is eliminated; or if it is not practicable to eliminate the risk, reduced so far as is practicable; and
  • To take specific measures in relation to certain circumstances (eg in relation to the atmosphere in confined spaces; in relation to fire, explosions and flammable gases or vapours; and so on)

An employer must ensure that an employee does not enter a confined space unless the employer has issued a confined space entry permit complying with these regulations. The entry permit is for one confined space only and may permit one or more employees to enter it.

Remember though, that there are some places that aren't defined as "confined spaces" are dangerous because they may be poorly ventilated.

Poorly ventilated workplaces are not likely to fit the definition of confined spaces under the Regulations as they do not meet all the factors outlined in the definition (eg. they generally have large entrances and doorways that do not restrict entry). However, these types of places are covered under Section 21 of the Occupational Health and Safety Act 2004 which states that employers must provide and maintain so far as is practicable for employees a working environment that is safe and without risks to health. Safe systems of work must be in place.

Poorly ventilated places that are not defined as confined spaces include:

  • cool stores.
  • freezer rooms.
  • controlled atmosphere rooms (used for the long term storage of fruit).
  • rooms with poor ventilation.

Three factors can make a poorly ventilated place dangerous to employees:

  1. the characteristics of the workplace.
  2. the type of work they are carrying out.
  3. a hazard such as an atmosphere dangerous to life (eg: low oxygen, toxic substances).

A poorly ventilated place may become dangerous:

  • if there is an unsafe level of atmospheric contaminants or the oxygen level is unsafe.
  • if the ventilation is poor and will not remove contaminants or maintain oxygen at a safe level.

Some examples of dangerous work in poorly ventilated places include:

  • LPG (liquid petroleum gas) forklift trucks in cool stores. Carbon monoxide may build up where poorly tuned LPG forklift trucks operate and ventilation is insufficient
  • Petrol or diesel vehicles or machines in cool stores, freezer rooms or other rooms. The levels of carbon monoxide emitted from these vehicles or machines will generally be of more concern than those of LPG-fuelled engines.
  • Activation of controlled atmosphere rooms used for the long term storage of fruit. The oxygen level in controlled atmosphere rooms may be as low as 2% and exposure will be life-threatening.
  • The use of cleaning solvents such as degreasing agents in small poorly ventilated rooms.

See Also:

  • Summary of Part 3.4 Confined Spaces section of the Occupational Health and Safety Regulations 2017
  • The WorkSafe Victoria webpage on Confined Spaces. Also: Compliance Code for Confined Spaces
  • An Australian Standard AS 2865 - Confined Spaces
  • The UK's Health and Safety Executive Confined Spaces at Work  webpage.
  • A great resource from Work Safe BC (British Columbia): a e-book, Confined Space Hazards (2014) which has clear information on what are confined spaces, incidents, identifying and explaining the various hazards and necessary systems of work, and more. The resource has good photos and a variety of videos.  

Last amended June 2020