NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Hydrogen sulfide

CAS
7783-06-4

H2S

RTECS
MX1225000
Synonyms & Trade Names

Hydrosulfuric acid, Sewer gas, Sulfuretted hydrogen
DOT ID & Guide
1053 / 117

Exposure
Limits

NIOSH REL: C 10 ppm (15 mg/m3) [10-minute]
OSHA PEL: C 20 ppm 50 ppm [10-minute maximum peak]
IDLH
100 ppm See: 7783064
Conversion
1 ppm = 1.40 mg/m3
Physical Description
Colorless gas with a strong odor of rotten eggs. [Note: Sense of smell becomes rapidly fatigued & can NOT be relied upon to warn of the continuous presence of H2S. Shipped as a liquefied compressed gas.]
MW: 34.1
BP: -77°F
FRZ: -122°F
Sol: 0.4%
VP: 17.6 atm
IP: 10.46 eV
RGasD: 1.19

Fl.P: NA (Gas)
UEL: 44.0%
LEL: 4.0%

Flammable Gas
Incompatibilities & Reactivities

Strong oxidizers, strong nitric acid, metals
Measurement Methods
NIOSH 6013; OSHA ID141
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Frostbite
Eyes: Frostbite
Wash skin: No recommendation
Remove: When wet (flammable)
Change: No recommendation
Provide: Frostbite wash
First Aid
(See procedures)
Eye: Frostbite
Skin: Frostbite
Breathing: Respiratory support

Respirator Recommendations
NIOSH
Up to 100 ppm:
(APF = 25) Any powered, air-purifying respirator with cartridge(s) providing protection against the compound of concern
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern
(APF = 10) Any supplied-air respirator*
(APF = 50) Any self-contained breathing apparatus with a full facepiece
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 canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Important additional information about respirator selection
Exposure Routes
inhalation, skin and/or eye contact
Symptoms
Irritation eyes, respiratory system; apnea, coma, convulsions; conjunctivitis, eye pain, lacrimation (discharge of tears), photophobia (abnormal visual intolerance to light), corneal vesiculation; dizziness, headache, lassitude (weakness, exhaustion), irritability, insomnia; gastrointestinal disturbance; liquid: frostbite
Target Organs
Eyes, respiratory system, central nervous system
See also: INTRODUCTION   See ICSC CARD: 0165   See MEDICAL TESTS: 0119