Respirator Types Overview

What it is

A respirator protects the wearer either by cleaning the air they breathe (air-purifying respirators: filtering facepieces, elastomeric half and full facepieces with filters or cartridges, and PAPRs) or by supplying breathable air from a clean source (supplied-air/airline respirators and SCBA). In the US, respirators must be NIOSH-approved under 42 CFR Part 84, and employers must run a written respiratory protection program under 29 CFR 1910.134 covering hazard evaluation, selection, medical evaluation, fit testing, training and maintenance.

How to identify

• NIOSH approval label with a TC number (e.g. TC-84A-xxxx for particulate filters). The full approval covers the specific facepiece and filter/cartridge combination listed by the manufacturer.
• Tight-fitting facepieces (quarter, half, full) seal to the face and require fit testing. Loose-fitting hoods, helmets and loose facepieces do not seal to the face.
• Air-purifying devices have filters or cartridges; atmosphere-supplying devices have an air hose or a cylinder.

OSHA assigned protection factors (29 CFR 1910.134(d)(3)(i)(A), Table 1)

Notes from the regulation: filtering facepieces (e.g. N95) are half masks with an APF of 10. The 25/1,000 helmet/hood value is 1,000 only where the manufacturer provides evidence of testing at that level; otherwise it is 25. APFs apply only within a complete program and do not apply to escape-only respirators.

Key points

• Maximum use concentration (MUC) = APF × the exposure limit, and never above the limit the manufacturer or a substance-specific OSHA standard sets (1910.134(d)(3)(i)(B)).
• IDLH atmospheres require a full facepiece pressure-demand SCBA certified for at least 30 minutes, or a full facepiece pressure-demand SAR with an auxiliary self-contained supply (1910.134(d)(2)).
• Air-purifying respirators do not supply oxygen and must not be used in oxygen-deficient atmospheres.
• Gas and vapor cartridges need an end-of-service-life indicator or a written change schedule (1910.134(d)(3)(iii)).
• Substance-specific OSHA standards (lead, asbestos, silica, others) can impose stricter requirements than Table 1.

Common mistakes

• Selling a respirator as a stand-alone product without the customer having a hazard evaluation, medical clearance and fit test.
• Mixing filters and facepieces from different manufacturers, which voids the NIOSH approval.
• Treating a surgical mask as a respirator.
• Using tight-fitting facepieces over facial hair at the seal.

Governing standards: 29 CFR 1910.134 (incl. (d)(3)(i)(A) Table 1); 42 CFR Part 84; NIOSH Respirator Selection Logic (Pub. 2005-100).

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.