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Last edited 17 Dec 2019
Working in confined conditions
A confined space is a space that is substantially enclosed, may have limited or restricted means of entry or exit, and poses a health hazard both from its spatially restricted nature and the access to and from it, or from the materials and objects that may be encountered. It hinders and potentially makes unsafe the activities of those inside. Confined spaces are not usually intended for continuous occupation.
 Types of confined space
- Low headroom basements.
- Crawl spaces.
- Catwalks, gantries and arbour pits.
- Lift and escalator pits.
- Attics and lofts.
- Storage bins.
- Open ditches.
- Poor air quality or insufficient oxygen for an entrant to breathe, or inhalation of stale or polluted air.
- Materials that could engulf a worker e.g a liquid or flowable solid substance.
- Total darkness.
- Atmospheric hazards, e.g flammable gas, airborne combustible/non-combustible gas.
- Entrapment hazards.
- Low bulkheads or very low ceiling heights that could cause head injuries.
- Sloping floors that could cause a slip.
- Walls that converge inward to a smaller cross-section.
- Very hot, unguarded heating or water pipes.
- Exposed live wires.
- Unguarded machinery.
- Chemical exposure.
If a confined space is so configured that it presents an entrapment hazard to entrants, they should be made aware of the fact prior to entering and should be required to have a permit to enter. They should also receive training to ensure they are aware of, and can deal with, the potential dangers. Pre-existing health problems should be identified or disclosed beforehand e.g workers who suffer from claustrophobia should not be allowed access to crawl spaces.
- The Confined Spaces Regulations 1997 which apply where the assessment identifies risks of serious injury from work in confined spaces. Critically, it mandates that entry to confined spaces should be avoided if the work can be undertaken another way, e.g by doing the work from the outside. But if unavoidable, a safe system of working should be chosen and adequate emergency measures should be in place before the work begins.
- The Management of Health and Safety at Work Regulations 1999. Under the MHSW Regulations, employers and self-employed people should carry out suitable and sufficient assessment of the risks for all work activities for the purpose of deciding what measures are necessary for safety. For confined spaces, this means identifying the hazards present, assessing the risks and determining what precautions to take.
Training will be required if workers are likely to have to work in confined spaces. The overall training objective is to protect those entering or working in or around a confined space. Such courses should teach the physical, chemical, and biological principles related to safe working within confined spaces. Potential entrants should be taught exactly what constitutes a confined space and the potential hazards they may encounter.
 Related articles on Designing Buildings Wiki
- Health and safety file.
- CDM Regulations.
- Deleterious materials.
- Fire and rescue service.
- Gas Safe.
- Health and safety.
- Health and safety inspector.
- Notify HSE.
- Occupational health.
- Reporting accidents and injuries on construction sites.
- Risk assessment under The Regulatory Reform (Fire Safety) Order 2005.
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