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respiratorcalc

Respirator selection

Hydrogen fluoride respirator selectionHF

Aluminum production, glass/semiconductor etching, stainless-steel pickling, petroleum alkylation catalyst, fluorochemical manufacture.

OSHA PEL
3 ppm
TWA 8-hr (Table Z-2)
NIOSH REL
3 ppm
TWA 8-hr (also 15-min Ceiling 6 ppm)
IDLH
30 ppm
Molecular weight
20.01 g/mol

These are federal OSHA limits. The PEL shown is the federal OSHA value. About two dozen states run their own OSHA-approved plans, and some — notably California (Cal/OSHA) — enforce lower or additional exposure limits. If you work under a state plan, check your state's PEL and enter it as a custom limit in the calculator.

Cartridge (limited use): Acid Gas (AG) — HF-specific NIOSH approval required — White band

An APR fitted with the correct cartridge is only adequate up to its MUC (below) — the cartridge must be able to capture hydrogen fluoride. HF is a severe systemic/percutaneous poison; use only a cartridge NIOSH-approved specifically for hydrogen fluoride. IDLH 30 ppm caps use; above it supplied air/SCBA required. Skin/eye protection is critical because HF penetrates tissue. You must establish a change-out schedule; never rely on taste or smell. See the cartridge & filter guide.

⚠ Skin absorption hazard: a respirator alone is not enough

Hydrogen fluoride penetrates skin and causes deep, delayed burns plus systemic fluoride toxicity, so skin and eye protection are essential in addition to a respirator. Wear chemical-protective gloves and clothing rated for this substance, plus eye and face protection. Flame-resistant (FR) clothing guards against flash fire, not chemical permeation, so it is not a substitute for a chemical-protective suit.

⚠ Skin absorption hazard: a respirator alone is not enough

Hydrogen fluoride penetrates skin and causes deep, delayed burns plus systemic fluoride toxicity, so skin and eye protection are essential in addition to a respirator. Choose gloves and protective clothing rated against this chemical (check the Safety Data Sheet for permeation data), and use eye protection.

Calculator for Hydrogen fluoride

Inputs

Hydrogen fluoride exposure

Unit
ppm

This is the measured airborne level from air monitoring / an exposure assessment by a qualified person — not a guess. No sampling data yet? See how to get an exposure concentration.

ppm

Presets fill the OSHA PEL. Many IH programs use the most protective of the OSHA PEL, NIOSH REL, or ACGIH TLV — enter whichever limit you use and the calculator applies it.

ppm

Enter molecular weight to convert values when you switch between ppm and mg/m³.

Result

Enter a concentration and an exposure limit to see the compliant respirators and their Maximum Use Concentration.

Hazard ratio = concentration ÷ OEL · Minimum APF must meet or exceed it · MUC = APF × OEL (capped at IDLH). Source: OSHA 29 CFR 1910.134(d)(3)(i)(A), Table 1 — Assigned Protection Factors. Last verified 2026-07-16.

Maximum use concentration for Hydrogen fluoride by respirator

MUC = APF × the OSHA PEL (3 ppm), capped at the IDLH (30 ppm). Use this as a reference for the highest concentration each respirator class may be used at.

RespiratorAPFMUC (ppm)
Air-Purifying Respirator · Quarter mask515
Air-Purifying Respirator · Half mask1030
Supplied-Air Respirator (Airline) · Half mask · Demand1030
Self-Contained Breathing Apparatus · Half mask · Demand1030
Powered Air-Purifying Respirator · Helmet / hood2530IDLH
Powered Air-Purifying Respirator · Loose-fitting facepiece2530IDLH
Supplied-Air Respirator (Airline) · Helmet / hood · Continuous flow2530IDLH
Supplied-Air Respirator (Airline) · Loose-fitting facepiece · Continuous flow2530IDLH
Air-Purifying Respirator · Full facepiece5030IDLH
Powered Air-Purifying Respirator · Half mask5030IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Demand5030IDLH
Supplied-Air Respirator (Airline) · Half mask · Continuous flow5030IDLH
Supplied-Air Respirator (Airline) · Half mask · Pressure-demand / positive-pressure5030IDLH
Self-Contained Breathing Apparatus · Full facepiece · Demand5030IDLH
Powered Air-Purifying Respirator · Full facepiece1,00030IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Continuous flow1,00030IDLH
Supplied-Air Respirator (Airline) · Full facepiece · Pressure-demand / positive-pressure1,00030IDLH
Self-Contained Breathing Apparatus · Full facepiece · Pressure-demand / positive-pressure10,00030IDLH

Notes

NIOSH REL TWA 3 ppm (2.5 mg/m3) AND 15-min Ceiling 6 ppm (5 mg/m3). OSHA PEL (Table Z-2) TWA 3 ppm. Values expressed as HF. IDLH 30 ppm. Conversion 1 ppm = 0.82 mg/m3; MW 20.0.

Sources

Data confidence: high. Values are cited from OSHA and NIOSH but should be verified against the current source and a qualified professional before use. See how this works.

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