NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Ethyl mercaptan

CAS
75-08-1

CH3CH2SH

RTECS
KI9625000
Synonyms & Trade Names

Ethanethiol, Ethyl sulfhydrate, Mercaptoethane
DOT ID & Guide
2363 / 129

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 See: 75081
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
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
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
Important additional information about respirator selection
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   See ICSC CARD: 0470   See MEDICAL TESTS: 0099