Its a question we are often asked. According to the Safe work in confined spaces.
Confined Space Regulation’s 1997.
Approved Code Of Practice (ACOP L101)
Under these Regulations a ‘confined space’ must have both of the following
defining features:
- (a) it must be a space which is substantially (though not always entirely) enclosed and
- (b) one or more of the specified risks must be present or reasonably foreseeable.
There are five specified risks which we must take into careful consideration.
“specified risk” means a risk of –
- Serious injury to any person at work arising from a fire or explosion;
- Loss of consciousness of any person at work arising from an increase in body temperature;
- Loss of consciousness or asphyxiation of any person at work arising from gas, fume, vapour or the lack of oxygen;
- Drowning of any person at work arising from an increase in the level of liquid;
- Asphyxiation of any person at work arising from a free flowing solid or the inability to reach a respirable environment due to entrapment by a free flowing solid.
Below is a flowchart extracted from the ACOP L101.
This can help you with the decision-making process.
It describes the specified risks – there must be at least one of these present or reasonably foreseeable to make any enclosed space a confined space within the 1997 Confined Space Regulations.
Confined space training should always be taken seriously and all entrants should be competent to the level of confined space that they will be required to enter, Low risk, Medium risk, High risk. This also include confined space supervisors who are non entrants, they require suitable training to oversee confined space operations.


