Confined space
An enclosed or partly enclosed space with limited access in which there is a risk of specified hazards such as harmful gases, lack of oxygen or flooding. Each jurisdiction defines confined space and its most hazardous category differently.
Also known as
By jurisdiction
UK HSE
“confined space”Exact equivalentDefined in the Confined Spaces Regulations 1997 (SI 1997/1713) as any place including any chamber, tank, vat, silo, pit, trench, pipe, sewer, flue, well or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk.
Irish HSA
“confined space”Close equivalentThe Safety, Health and Welfare at Work (General Application) Regulations 2007 (SI 299/2007), Part 7, sets requirements for work in confined spaces. Ireland defines confined space broadly and requires risk assessment, safe work procedures and rescue planning.
US OSHA
“confined space”Close equivalent“29 CFR 1910.146(b) defines confined space as a space large enough for an employee to enter, with limited means of entry or exit, not designed for continuous employee occupancy. A permit-required confined space additionally contains or has the potential to contain a serious safety or health hazard.”
Note: OSHA distinguishes permit-required from non-permit-required confined spaces; this split does not exist in GB or Irish law.
Practitioner note: UK/Irish definition focuses on reasonably foreseeable specified risk, not just physical size. OSHA distinguishes permit-required and non-permit-required confined spaces based on whether serious hazards are present.