Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7783–06–4
NIOSH REL: 10 ppm (15 mg/m3) 10-minute CEILING
Current OSHA PEL: 20 ppm CEILING, 50 ppm 10-minute MAXIMUM PEAK
1989 OSHA PEL: 10 ppm (14 mg/m3) TWA, 15 ppm (21 mg/m3) STEL
1993-1994 ACGIH TLV: 10 ppm (14 mg/m3) TWA, 15 ppm (21 mg/m3) STEL
Description of Substance: Colorless gas with a strong odor of rotten eggs.
LEL: 4.0% (10% LEL, 4,000 ppm)
Original (SCP) IDLH: 300 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Patty  that 170 to 300 ppm is the maximum concentration that can be endured for 1 hour without serious consequences; 400 to 700 ppm is dangerous after exposure of 0.5 to 1 hour [Henderson and Haggard 1943]. AIHA  reported that 400 to 700 ppm caused loss of consciousness and possible death in 0.5 to 1 hour [MCA 1950].
Existing short-term exposure guidelines: 1991 American Industrial Hygiene Association (AIHA) Emergency Response Planning Guidelines (ERPGs):
ERPG-1: 0.1 ppm (60-minute)
ERPG-2: 30 ppm (60-minute)
ERPG-3: 100 ppm (60-minute)
National Research Council [NRC 1985] Emergency Exposure Guidance Levels (EEGLs):
10-minute EEGL: 50 ppm
24-hour EEGL: 10 ppm
ACUTE TOXICITY DATA:
Lethal concentration data:
|Species||Reference||LC50(ppm)||LCLo(ppm)||Time||Adjusted 0.5-hrLC (CF*)||Derived value|
|Rat||Back et al. 1972||713||—–||1 hr||977 ppm (1.37)||98 ppm|
|Mouse||Back et al. 1972||673||—–||1 hr||922 ppm (1.37)||92 ppm|
|Human||Lefaux 1968||—–||600||30 min||600 ppm (1.0)||60 ppm|
|Mouse||MacEwen and Vernot 1972||634||—–||1 hr||869 ppm (1.37)||87 ppm|
|Human||Tab Biol Per 1933||—–||800||5 min||354 ppm (0.44)||35 ppm|
|Rat||Tansey et al. 1981||444||—–||4 hr||1,141 ppm (2.57)||114 ppm|
*Note: Conversion factor (CF) was determined with “n” = 2.2 [ten Berge et al. 1986].
Other human data: It has been reported that 170 to 300 ppm is the maximum concentration that can be endured for 1 hour without serious consequences [Henderson and Haggard 1943] and that olfactory fatigue occurs at 100 ppm [Poda 1966]. It has also been reported that 50 to 100 ppm causes mild conjunctivitis and respiratory irritation after 1 hour; 500 to 700 ppm may be dangerous in 0.5 to 1 hour; 700 to 1,000 ppm results in rapid unconsciousness, cessation of respiration, and death; and 1,000 to 2,000 ppm results in unconsciousness, cessation of respiration, and death in a few minutes [Yant 1930].
|Revised IDLH: 100 ppmBasis for revised IDLH: The revised IDLH for hydrogen sulfide is 100 ppm based on acute inhalation toxicity data in humans [Henderson and Haggard 1943; Poda 1966; Yant 1930] and animals [Back et al. 1972; MacEwen and Vernot 1972; Tansey et al. 1981].|
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3. Henderson Y, Haggard HW . Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 245.
4. Lefaux R . Practical toxicology of plastics. Cleveland, OH: Chemical Rubber Co., p. 207.
5. MacEwen JD, Vernot EH . Toxic Hazards Research Unit annual report: 1972. Wright-Patterson Air Force Base, OH: Air Force Systems Command, Aerospace Medical Division, Aerospace Medical Research Laboratory Report, AMRL-TR-72-62.
6. MCA . Chemical safety data sheet SD-36: properties and essential information for safe handling and use of hydrogen sulfide. Washington, DC: Manufacturing Chemists Association, pp. 1-13.
7. NRC . Emergency and continuous exposure guidance levels for selected airborne contaminants. Vol. 4. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 55-68.
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9. Poda GA . Hydrogen sulfide can be handled safety. Arch Environ Health 12:795-800.
10. Tab Biol Per ; 3:231 (in German).
11. Tansey MF, Kendall FM, Fantasia J, Landin WE, Oberly R . Acute and subchronic toxicity studies of rats exposed to vapors of methyl mercaptan and other reduced sulfur compounds. J Toxicol Environ Health 8:71-88.
12. ten Berge WF, Zwart A, Appelman LM . Concentration-time mortality response relationship of irritant and systematically acting vapours and gases. J Haz Mat 13:301-309.
13. Yant WP . Hydrogen sulfide in industry: occurrence, effects and treatment. Am J Public Health 20:598-608.