Hydrogen sulfide

  • Sulfureted hydrogen
  • Sulfur hydride
  • Stink damp
Formula
H2S
Structure
Description
A colorless gas having a strong odor of rotten eggs. Fatigues the sense of smell which cannot be counted on to warn of the continued presence of the gas.
Uses
To produce elemental sulfur and sulfuric acid, in Manufacture of heavy water and other chemicals, in metallurgy, as analytical reagent.

Registry Numbers and Inventories.
CAS
7783-06-4
EC (EINECS/ELINCS)
231-977-3
EC Index Number
016-001-00-4
EC Class
Extremely flammable; Very toxic; Dangerous for the Environment
RTECS
MX1225000
RTECS class
Reproductive Effector; Human Data
UN (DOT)
1053
Merck
12,4843
Beilstein/Gmelin
303 (G)
RCRA
U135
Swiss Giftliste 1
G-2103
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
H2S
Formula mass
34.07
Melting point, °C
-85.5
Boiling point, °C
-60.3
Vapor pressure, mmHg
13426 (20 C)
Vapor density (air=1)
1.19
Odor Threshold Odor threshold 0.05 ppm
Critical temperature
100.4
Critical pressure
88.2
Density
1.1 g/cm3 (20 C)
Solubility in water
4 g/L
Viscosity
0.00143 P (6 C)
Surface tension
30 g/s2
Refractive index
1.3682 (20 C)
Dipole moment
0.974 D
Dielectric constant
1.00375 (14 C)
pKa/pKb
7.04 (pKa)
Thermal expansion
0.00174/K (-84 C)
Heat of fusion
2.4 kJ/mol
Heat of vaporization
17.7 kJ/mol
Heat of combustion
-519 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling
All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection
Wear appropriate protective gloves, clothing and goggles. Always wear thermal protective clothing when handling refrigerated/cryogenic liquids.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. Attempt to stop leak if without undue personnel hazard. Use water spray to knock-down vapors. Vapor knockdown water is corrosive or toxic and should be diked for containment. Land spill: Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. Absorb bulk liquid with fly ash or cement powder. Neutralize with agricultural lime (CaO), crushed limestone (CaCO3) or sodium bicarbonate (NaHCO3). Water spill: Neutralize with agricultural lime (CaO), crushed limestone (CaCO3), or sodium bicarbonate (NaHCO3).
Stability
Stable - explosive mixtures with air over a wide range. Dangerously reactive with fuming or strong nitric acid and strong oxidizing materials.
Incompatibilities
Reacts as an acid and as a reducing agent Explodes on contact with oxygen difluoride, bromine pentafluoride, chlorine trifluoride, dichlorine oxide, silver fulminate May react similarly with other powdered metals Reacts exothermically with bases.
Decomposition
When heated to decomposition it emits highly toxic fumes of sulfoxides.

Fire.
Flash Point,°C
-82.4
Autoignition, °C
260
Upper exp. limit, %
46
Lower exp. limit, %
4.3
Fire fighting
Stop flow of gas. Use water to keep fire-exposed containers cool and to protect men effecting the shut-off. Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Wear positive pressure breathing apparatus and special protective clothing. Evacuate area endangered by gas. Move container from fire area. Stay away from ends of tanks. Withdraw immediately in case of rising sound from venting safety device or any discoloration on tank due to fire. Cool containers with water using unmanned device until well after the fire is out. Isolate for one-half mile in all directions if tank car or truck is involved in fire.A very flammable gas. For small fires let burn unless leak can be stopped immediately. For large fires, use water spray, fog or foam.
Fire potential
Very flammable, combustion imminent. May travel considerable distance to a source of ignition and flash back.
Hazards
Compound is heavier than air and may travel a considerable distance to source of ignition and flash back. It forms explosive mixtures with air over a wide range. Also reacts explosively with bromine pentafluoride, chlorine trifluoride, nitrogen triiodide, nitrogen trichloride, oxygen difluoride, and phenyl diazonium chloride. When heated to decomposition, it emits highly toxic fumes of oxides of sulfur. Incompatible with many materials including strong oxidizers, metals, strong nitric acid, bromine pentafluoride, chlorine trifluoride, nitrogen triiodide, nitrogen trichloride, oxygen difluoride and phenyl diazonium chloride. Avoid physical damage to containers; sources of ignition; storage near nitric acid, strong oxidizing materials, and corrosive liquids or gases.
Combustion products
Fire will produce irritating, corrosive and/or toxic gases.
Health
4
 
Flammability
4
 
 
Reactivity
0
 

Health.
Exposure limit(s)
TLV: 10 ppm; 14 mg/m3 (as TWA); 15 ppm; 21 mg/m3 (STEL) (ACGIH 1997). OSHA PEL: C 20 ppm 50 ppm 10-minute maximum peak NIOSH REL: C 10 ppm (15 mg/m3) 10-minute NIOSH IDLH: 100 ppm
Poison_Class
2
Exposure effects
Patients may acutely present with low heart rate, rapid heart rate, hyperventilation, respiratory depression even to the point of apnea, and/or hypo-/elevated blood pressure. Asphyxial seizures, coma, and death associated with rapid respiratory paralysis may be noted following exposure to high concentrations. Headache, sweating, vertigo, anosmia, irritability, staggering gait, disorientation, somnolence, weakness, confusion, and delirium may be noted following exposure to non-fatal levels. Spontaneous abortions have occurred after exposure to life-threatening concentrations.
   Ingestion
Nausea and vomiting may be noted. Weight loss can be seen with chronic exposure.
   Inhalation
Respiratory depression, cyanosis, pulmonary edema, bronchitis, and dyspnea may be noted following exposure to non-fatal concentrations.
   Skin
Skin exposure may result in severe pain, itching, and erythema, especially in moist areas. Cyanosis may be noted following severe exposure.
   Eyes
May cause burns.

First aid
 
   Ingestion
Hydrogen sulfide is a gas at room temperature (harbison, 1998), making ingestion unlikely.
   Inhalation
Immediately move patient to fresh air and administer 100 percent oxygen. Prevent self-exposure and possible death by wearing a self-contained breathing apparatus to rescue the victim.
   Skin
Remove contaminated clothing and wash exposed area thoroughly with soap and water. A physician should examine the area if irritation or pain persists.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
1053
Response guide
Hazard class
2.3
PRTC
T
USCG CHRIS Code
HDS
 
Std. Transport #
4920513