Hydrogen sulfide
Synonyms & Trade Names
Hydrosulfuric acid, Sewer gas, Sulfuretted hydrogenExposure Limits
NIOSH REL
C 10 ppm (15 mg/m3) [10-minute]OSHA PEL
C 20 ppm 50 ppm [10-minute maximum peak] See Appendix GPhysical 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.]Molecular Weight
34.1Boiling Point
-77°FFreezing Point
-122°FSolubility
0.4%Vapor Pressure
17.6 atmIonization Potential
10.46 eVFlash Point
NA (Gas)Upper Exposive Limit
44.0%Lower Explosive Limit
4.0%Relative Gas Density
1.19Incompatibilities & Reactivities
Strong oxidizers, strong nitric acid, metalsExposure Routes
inhalation, skin and/or eye contactSymptoms
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: frostbiteTarget Organs
Eyes, respiratory system, central nervous systemPersonal Protection/Sanitation
(See protection codes)Skin:Frostbite
Eyes:Frostbite
Wash skin:No recommendation
Remove:When wet (flammable)
Change:No recommendation
Provide:Frostbite wash
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
- Page last reviewed:April 11, 2016
- Page last updated:April 11, 2016
- Content source:
- National Institute for Occupational Safety and Health (NIOSH) Education and Information Division