29 CFR 1910.134 Appendix D Sometimes, workers may wear respirators to avoid exposures to hazards, even if the amount of hazardous substance does not exceed the limits set by OSHA standards.

Respirator hose-line pressures must typically be maintained in the 65-100 pounds per square inch gauge (psig) range. The Occupational Safety and Health Administration (OSHA) and NIOSH regulations prohibit the actual hose length from the respirator manifold to exceed 300 feet in length.

A non-rebreather mask is a type of oxygen mask that gives a person a lot of oxygen, typically in an emergency. There's a risk of suffocation since it doesn't allow you to breathe in any outside or room air. For this reason, non-rebreather masks are typically for hospital or emergency department use only.

The OSHA Respiratory Protection standard (29 CFR 1910.134) requires employees to be fit tested prior to the initial use of a respirator, and whenever a different respirator facepiece (i.e., of a different size, style, model or make) is used (see 29 CFR 1910.134(f)(2)).