First of all, forget all your preconceptions of what a confined space is; forget about the size of the space, forget about how difficult or risky it is to get in to or out of a confined space.
A Confined space is by nature a substantially enclosed space, though not always entirely, that has certain hazards within that space that could cause harm. So, to summarise, for a space to be a confined space it needs to be:
The specified risks are:
Further Reading
“Under domestic law (the Health and Safety at Work etc Act 1974) employers are responsible for ensuring the safety of their employees and others. This responsibility is reinforced by regulations.”
These regulations contain the following key duties:
The Management of Health and Safety at Work Regulations 1999 [2]
“Require employers and self-employed people to carry out a suitable and sufficient assessment of the risks for all work activities for the purpose of deciding what measures are necessary for safety. For work in confined spaces this means identifying the hazards present, assessing the risks and determining what precautions to take.” Health and Safety Executive http://www.hse.gov.uk/confinedspace/legislation.htm