EHS Topic of the Month: Confined Space

OSHA regulation 29 CFR 1910.146 covers "permit-required confined spaces." This regulation provides rules regarding practices and procedures designed to protect workers in confined spaces.

A confined space:

• Is large enough and so configured that an employee can bodily enter and perform assigned work;
• Has limited or restricted means for entry or exit (for example, tanks, vessels, silos, storage bins, hoppers, vaults, and pits are spaces that may have limited means of entry); and
• Is not designed for continuous employee occupancy.

A permit-required confined space (permit space) is a confined space that has one or more of the following characteristics:

• Contains or has a potential to contain a hazardous atmosphere;
• Contains a material that has the potential for engulfing an entrant;
• Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or
• Contains any other recognized serious safety or health hazard.

A non-permit confined space is a confined space that does not contain or, with respect to atmospheric hazards, have the potential to contain, any hazard capable of causing death or serious physical harm.

OSHA requires employers to evaluate their workplaces to determine if they include any permit-required confined spaces. The decision flow chart below, found in Appendix A of the OSHA confined space regulation, is a useful to for employers to determine when a confined space requires a permit.

If a workplace includes permit-required confined spaces, the employer must inform employees by posting signs warning about the existence, location, and hazards of these spaces. 

If an employer determines that their employees may need to enter a permit-required confined space, OSHA requires that they prepare a written Confined Space Program. 

A customizable template of a written Confined Space Program can be downloaded by NFFS members at www.nffs.org/osha-templates.