# NIOSH Pocket Guide to Chemical Hazards
Ethyl mercaptan | CAS 75-08-1
CH3CH2SH | RTECS K19625000
Synonyms & Trade Names Ethanethiol, Ethyl sulfhydrate, Mercaptoethane | DOT ID & Guide 2363 130
Exposure Limits | NIOSH REL: C 0.5 ppm (1.3 mg/m3) [15-minute]
OSHA PEL†: C 10 ppm (25 mg/m3)
IDLH 500 ppm | Conversion 1 ppm = 2.54 mg/m3
Physical Description Colorless liquid with a strong, skunk-like odor. [Note: A gas above 95°F.]
MW: 62.1 | BP: 95°F | FRZ: -228°F | Sol: 0.7%
VP: 442 mmHg | IP: 9.29 eV |  | Sp.Gr: 0.84
Fl.P: -55°F | UEL: 18.0% | LEL: 2.8% |
Class IA Flammable Liquid: Fl.P. below 73°F and BP below 100°F.
Incompatibilities & Reactivities Strong oxidizers [Note: Reacts violently with calcium hypochlorite.]
Measurement Methods NIOSH 2542
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH Up to 5 ppm: (APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s)/(APF = 10) Any supplied-air respirator Up to 12.5 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s) Up to 25 ppm: (APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 500 ppm: (APF = 1000) Any supplied-air respirator operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation mucous membrane; headache, nausea; in animals: incoordination, lassitude (weakness, exhaustion); liver, kidney damage; cyanosis; narcosis
Target Organs Eyes, respiratory system, liver, kidneys, blood
See also: INTRODUCTION