Skip directly to local search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Enter search terms separated by spaces.

Hydrogen sulfide

Synonyms & Trade Names
Hydrosulfuric acid, Sewer gas, Sulfuretted hydrogen
CAS No.
7783-06-4
RTECS No.
MX1225000
DOT ID & Guide
1053 117
Formula
H2S
Conversion
1 ppm = 1.40 mg/m3
IDLH
100 ppm
See: 7783064
Exposure Limits
NIOSH REL
: C 10 ppm (15 mg/m3) [10-minute]
OSHA PEL
: C 20 ppm 50 ppm [10-minute maximum peak]
Measurement Methods

NIOSH 6013;
OSHA ID141
See: NMAM or OSHA Methods
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
Fl.P:
NA (Gas)
UEL:
44.0%
LEL:
4.0%
RGasD:
1.19
Flammable Gas
Incompatibilities & Reactivities
Strong oxidizers, strong nitric acid, metals
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
Personal Protection/Sanitation
(See protection codes)
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

See also: INTRODUCTION   See ICSC CARD: 0165
 
Contact Us:
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Road Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO