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.

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)).

∎ All employees using a negative or positive pressure tight-fitting facepiece respirator must pass an appropriate qualitative fit test (QLFT) or quantitative fit test (QNFT). ∎ Fit testing is required prior to initial use, whenever a different respirator facepiece is used, and at least annually thereafter.

If a respirator does not pass an inspection and/or seal check, it must be repaired, discarded, or removed from service. This is important because a respirator that does not pass inspection may not provide adequate protection against harmful particles or substances.