Examples of Confined Spaces
Confined spaces can include any existing tank, tower, sewer, sewer station, manhole, sump, vault, vat, grease pit, tunnel, or other similar confined space.
Hazards
Due to the nature of a confined space's shape, size, lack of ventilation, proximity to toxic gases, and other contributing substances, confined spaces present many hazards to employees. Potential confined space hazards include hazardous atmospheres, and general safety hazards.
Hazardous atmospheres expose employees to the risk of death, incapacitation, injury, or acute illness. Hazardous atmospheres include:
- A flammable gas, vapor, or mist in excess of ten percent (10%) of its lower flammable limit (LFL)
- An airborne combustible dust at a concentration that obscures vision at a distance of five feet or less
- An atmospheric oxygen concentration below 19.5 percent or above 23.5 percent
- An atmospheric concentration of any substance for which a permissible exposure limit is published in Subpart Z of 29 CFR Part 1910 and could result in employee exposure in excess of its permissible limit(s)
- Any atmospheric condition recognized as immediately dangerous to life or health (IDLH)
General safety hazards include but are not limited to:
- Physical hazards
- Structural hazards
- Electrical hazards
- Mechanical hazards
- Biological hazards
- Radiation hazards
