A confined space has limited openings for entry or exit, is large enough for entering and working, and is not designed for continuous worker occupancy. Confined spaces include underground vaults, tanks, storage bins, manholes, pits, silos, underground utility vaults and pipelines.

Permit-required confined spaces are confined spaces that:

• May contain a hazardous or potentially hazardous atmosphere.
• May contain a material which can engulf an entrant.
• May contain walls that converge inward or floors that slope downward and taper into a smaller area which could trap or asphyxiate an entrant.
• May contain other serious physical hazards such as unguarded machines or exposed live wires.
• Must be identified by the employer who must inform exposed employees of the existence and location of such spaces and their hazards.

What to Do

• Do not enter permit-required confined spaces without being trained and without having a permit to enter.
• Review, understand and follow employer’s procedures before entering permit-required confined spaces and know how and when to exit.
• Before entry, identify any physical hazards.
• Before and during entry, test and monitor for oxygen content, flammability, toxicity or explosive hazards as necessary.
• Use employer’s fall protection, rescue, air monitoring, ventilation, lighting and communication equipment according to entry procedures.
• Maintain contact at all times with a trained attendant either visually, via phone, or by two-way radio. This monitoring system enables the attendant and entry supervisor to order you to evacuate and to alert appropriately trained rescue personnel to rescue entrants when needed.