Confined Spaces
Confined spaces include manholes, sewers, vaults, tanks, and boilers encountered during new construction or repair and maintenance work. Exposure to chemicals or a lack of oxygen in confined spaces can be deadly. Airborne chemicals can quickly reach dangerous levels in confined spaces that are not ventilated. Typical hazardous atmospheres within confined spaces include:
- lack of oxygen,
- carbon monoxide,
- hydrogen sulfide,
- welding fumes, and
- solvent vapors.
Oxygen deficiency is especially dangerous because workers cannot reliably detect it without atmospheric testing. At very low oxygen levels, a worker entering a confined space may quickly become impaired or collapse.
For more information on confined spaces in general industry, see course 713 Confined Space Program and course 816 Confined Space Safety in Construction.
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1-10. Why is oxygen deficiency so dangerous in confined spaces?
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