A confined space is large enough for a worker to enter and perform his/her job. It is limited in that the space has a restricted entry or exit. This space is only occupied for the purposes of performing work and only for the duration of the work activity.
Examples of confined spaces include, but are not limited to, silos, storage bins, pits, tanks, vaults, vessels, and similar structures. When a hazardous atmosphere or environment poses a serious threat, a permit is usually required. However, in certain circumstances, an employer may be exempt from a permit by having the worker use continuous forced air ventilation. It is always best to check with The U.S. Occupational and Safety Administration (OSHA).
Confined spaces are considered potentially hazardous since they are often poorly ventilated or may contain toxic gases. Moreover, a worker may find it difficult to maintain an assured distance from electrical wiring. Employers will be required to evaluate all potential hazards a confined space may pose to their workers.
A crawl space may also be defined as a confined space. OSHA is creating new requirements for those working in crawl spaces. This will entail assessing each jobsite for the location of all confined spaces and potential for hazardous situations.