By Cameron Hunter - Standards Australia Committee Member for AS 2865-2009

The precise occupational definition of Confined Space varies from country to country and state to state.

The occupational definition is very different to the term "confined space" used in normal conversation. In normal conversation the term "confined space" means an area where a person is - 

• not free to move about
• enclosed by a confining fence
• deprived of liberty; especially placed under arrest or restraint, or
• captive: in captivity 

This is NOT the definition used in the workplace.  In the workplace a confined space may be large and have many entry / exit points.  In general a confined space may be physically difficult to enter or exit and may have a hazard (such as an unsafe atmosphere or engulfment) which is immediately dangerous to life or health. 

For a precise definition of a confined space please refer to your local regulations.

 Also see Article How to Classify Confined Spaces  and  Blog - AS2865-2009