What is a confined space?
A confined space is not defined by its size but rather the hazards associated with a set of specific circumstances, which are:
- physical characteristic of the space
- inherent hazards associated with the space
- type of work being conducted inside or around the space.
A confined space means an enclosed or partially enclosed space that is not intended or designed primarily for human occupancy, within which there is a risk of one or more of the following:
- an oxygen concentration outside the safe oxygen range
- a concentration of airborne contaminants that may cause impairment, loss of consciousness or asphyxiation
- a concentration of flammable airborne contaminants that may cause injury from fire or explosion
- engulfment in a stored free-flowing solid or a rising level of liquid that may cause suffocation or drowning.
Other hazards in confined spaces may include:
- limited or restricted access, making it difficult in an emergency to rescue a worker
- hazards associated with the tasks being conducted inside or around the space
- hazards associated with other tasks being conducted inside or around the space
- hazardous contaminants that may be trapped in sludge, scale or other deposits, brickwork or behind loose linings, in liquid traps, or in instrument fittings, and may be released only when, for example, it is disturbed or heat is applied.
Where are confined spaces found?
Examples of potential confined spaces include:
- storage tanks and bins
- process vessels
- sumps and pump hoppers
- abandoned tunnels or shafts
- degreasing pits
- excavation holes and trenches
- refrigeration units
- tanks or vats
- wheel motor housings.
Requirements for work undertaken in a confined space
Regulation 4.2 of the Mines Safety and Inspection Regulations 1995 requires compliance with the Australian Standard AS 2865 Confined spaces in relation to work carried out in a confined space at the mine.
Refer to r. 4.2 of the Mines Safety and Inspection Regulations 1995
Australian Standards are available from Standards Australia.
Reclassifying a confined space
While the process of reclassification is possible under the definition of AS 2865, it is extremely important that reclassification of confined spaces is undertaken with full consideration of all inherent and introduced hazards, and the risks associated with these spaces.
Mines Safety Bulletin 111 When can a confined space be reclassified? outlines what needs to be considered before reclassifying a confined space.
You can search for mines safety bulletins and other safety alerts in the Publications and resources area and download them as a PDF.
Below is the list of documents and links that you may find useful.
Safe Work Australia’s Model code of practice - Confined spaces was developed to assist with the identification and management of risks associated with confined spaces in the workplace.