Permit-Required Confined Space
A confined space with hazards requiring a permit before entry, per 29 CFR 1910.146.
What it is
A Permit-Required Confined Space (PRCS) is a confined space that, in addition to meeting the basic confined-space definition (limited entry/egress, not designed for continuous occupancy), contains or has the potential to contain a hazardous atmosphere, an engulfment hazard, an inwardly-converging configuration, or any other recognized serious hazard.
Plain-English explanation
Not every confined space is a PRCS. A PRCS is a confined space that’s actively dangerous, requiring a written entry permit, an attendant outside the space, and a rescue plan.
The standard governing PRCS is 29 CFR 1910.146 in General Industry, with parallel rules in Construction (1926 Subpart AA).
Why it matters
PRCS entry incidents are a leading cause of workplace fatalities. The standard is one of the most frequently cited in General Industry inspections.