Different types of confined spaces exist, and some of them pose dangers that necessarily require the use of a permit. A confined space, according to OSHA 29 CFR 1910.146 “Permit-required confined spaces”, is a space that is sufficiently large and configured to enable an individual to access in full body to execute project tasks, the point of entry and/or exit is limited or constrained, as in the case of a vessel or tank, and the space was not constructed for employee occupancy for an extended period of time.
The main risks of entering a permit-required confined space can be described, according to OSHA, as follows:
- Exposure to hazardous atmosphere.
- Exposure to materials with potential for engulfing.
- Possible entrapment or asphyxiation.
OSHA's 1910.146 standard lists certain preventative steps that apply to both the primary employer and any contractor doing asset inspections, including but not limited to:
- Pre-entry hazard evaluations.
- Specification of acceptable entry conditions.
- Verification of the conditions as acceptable.
- Coordination of entry operations.
- Isolation of the confined space.
- Usage of forced ventilation.
- Purging, inerting, flushing, or ventilating the permit space as necessary to eliminate or control atmospheric hazards.
- Provision of personal protective equipment, lightning equipment and communication equipment for the person entering the confined space.