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Air Monitoring Applications - Petrochemical

Mercaptans Air Sampling

Petrochemical Applications main pageMethyl-, Ethyl-, Butyl- Mercaptans
Mercaptans are a group of sulfur containing organic compounds that impart a cabbage-like odor into the environment. Mercaptans are found in crude petroleum. Mercaptan is a non-toxic chemical added to natural gas to make it easier to detect in case of a gas leak because of the foul smell. Mercaptans are also found in jet fuels.


Exposure Limits
Contaminant/
Agency
Exposure Limit
Methyl Mercaptan
OSHA (PEL) for General Industry: 10 ppm (20 mg/m³) Ceiling
for Construction Industry: 0.5 ppm (1.0 mg/m³) TWA
for Maritime: 0.5 ppm (1.0 mg/m³) TWA
ACGIH (TLV) 0.5 ppm, (0.98 mg/m³) TWA
NIOSH (REL) 0.5 ppm (1.0 mg/m³) Ceiling (15 Minutes)
NIOSH (IDHL) 150 ppm
Butyl Mercaptan
OSHA (PEL) for General Industry: 10 ppm (35 mg/m³) TWA
for Construction Industry: 0.5 ppm (1.5 mg/m³) TWA
for Maritime: 0.5 ppm (1.5 mg/m³) TWA
ACGIH (TLV) 0.5 ppm, (1.8 mg/m³) TWA
NIOSH (REL) 0.5 ppm (1.8 mg/m³) Ceiling (15 Minutes)
NIOSH (IDHL) 500 ppm
Ethyl Mercaptan
OSHA (PEL) for General Industry: 10 ppm (25 mg/m³) Ceiling
for Construction Industry: 0.5 ppm (1.0 mg/m³) TWA
for Maritime: 0.5 ppm (1.0 mg/m³) TWA
ACGIH (TLV) 0.5 ppm, (1.3 mg/m³) TWA
NIOSH (REL) 0.5 ppm (1.0 mg/m³) Ceiling (15 Minutes)
NIOSH (IDHL) 500 ppm
(TWA=Time-weighted average; TLV=Threshold Limit Value; PEL=Personal Exposure Limit, REL=Recommended Exposure Limit; IDHL=Immediately Dangerous to Life and Health concentration)

References
ATSDR Methyl Mercaptan Medical Management Guidelines (MMG) (PDF)