The term “confined space” can be used to describe a wide variety of work areas – underground utility vaults, storage containers, manholes, silos, mines, railroad cars or pipelines. Any space that is large enough to enter but not designed for continuous occupancy falls under the category of a confined space.
Permit-required confined spaces present additional risks. According to OSHA, permit-required confined spaces include areas that:
- May contain a hazardous or potentially hazardous atmosphere
- May contain a material that could engulf an occupant
- May contain walls that converge inward or slope downward into a smaller area that could trap or asphyxiate an occupant
- May contain physical hazards, such as unguarded machines or exposed live wires
These areas should always be clearly identified by the employer, and only those who are properly trained should be allowed entry.
To safely work in a permit-required confined space, OSHA suggests workers:
- Understand and follow the employer’s procedures about when and how to exit the space.
- Identify any physical hazards prior to entry.
- Before and during entry, monitor and test for oxygen content, flammability, toxicity or explosive hazards, as necessary.
- Use fall protection, rescue, air monitoring, ventilation, lighting and communication equipment according to entry procedures.
- Maintain constant contact with a trained attendant either visually, via phone or with a two-way radio. This allows supervisors to call for an evacuation or send in a rescue team as soon as possible.