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Sulfur dioxide
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7446–09–5
NIOSH REL: 2 ppm (5 mg/m3) TWA, 5 ppm (13 mg/m3) STEL
Current OSHA PEL: 5 ppm (13 mg/m3) TWA
1989 OSHA PEL: 2 ppm (5 mg/m3) TWA, 5 ppm (13 mg/m3) STEL
1993-1994 ACGIH TLV: 2 ppm (5.2 mg/m3) TWA, 5 ppm (13 mg/m3) STEL
Description of substance: Colorless gas with a characteristic, irritating, pungent odor.
LEL: . . . Nonflammable Gas
Original (SCP) IDLH: 100 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by AIHA [1955] that 50 to 100 ppm is considered the maximum concentration for exposures of 0.5 to 1 hour [Henderson and Haggard 1943]. With regard to the atmospheric concentration immediately hazardous to life, AIHA [1955] reported that 400 to 500 ppm is considered dangerous for even short periods of exposure [Henderson and Haggard 1943] and that exposure to unendurable concentrations is not necessarily hazardous if escape is made within a few minutes.
Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):
10-minute EEGL: 30 ppm
30-minute EEGL: 20 ppm
60-minute EEGL: 10 ppm
24-hour EEGL: 5 ppm
ACUTE TOXICITY DATA:
Lethal concentration data:
| Species | Reference | LC50(ppm) | LCLo(ppm) | Time | Adjusted 0.5-hrLC (CF) | Derived value |
|---|---|---|---|---|---|---|
| Rat | Flury & Zernik 1935 | —– | 993 | 20 min | 864 ppm (0.87) | 86 ppm |
| Rat | Flury &Zernik 1935 | —– | 611 | 5 hr | 1,314 ppm (2.15) | 131 ppm |
| Mouse | Flury &Zernik 1935 | —– | 764 | 20 min | 665 ppm (0.87) | 67 ppm |
| Mouse | Hilado &Machado 1977 | 3,000 | —– | 30 min | 3,000 ppm (1.0) | 300 ppm |
| Rat | Kinkead & Einhaus 1984 | 2,520 | —– | 1 hr | 3,150 ppm (1.25) | 315 ppm |
| Human | Shupe et al. 1972 | —– | 1,000 | 10 min | 690 ppm (0.69) | 69 ppm |
| Human | Tab Biol Per 1933 | —– | 3,000 | 5 min | 1,500 ppm (0.5) | 150 ppm |
Other animal data: RD50 (mouse), 117 ppm [Alarie 1981].
Other human data: The maximum concentration for exposures of 0.5 to 1 hour is considered to be 50 to 100 ppm [Henderson and Haggard 1943]. It has been reported that 400 to 500 ppm is considered dangerous for even short periods of exposure [Henderson and Haggard 1943].
| Revised IDLH: 100 ppm [Unchanged]Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Henderson and Haggard 1943; Shupe et al. 1972; Tab Biol Per 1933], the original IDLH for sulfur dioxide (100 ppm) is not being revised at this time. |
REFERENCES:
1. AIHA [1955]. Sulfur dioxide. In: Hygienic guide series. Am Ind Hyg Assoc Q 16:332-333.
2. Alarie Y [1981]. Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.
3. Flury F, Zernik F [1935]. Zusammenstellung der toxischen und letalen dosen für die gebräuchlichsten gifte und versuchstiere. Abder Hand Biol Arbeitsmethod 4:1289-1422 (in German). [From Back KC, Thomas AA, MacEwen JD [1972]. Reclassification of materials listed as transportation health hazards. Wright-Patterson Air Force Base, OH: 6570th Aerospace Medical Research Laboratory, Report No. TSA-20-72-3, pp. A250 to A251.]
4. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 131.
5. Hilado CJ, Machado AM [1977]. Effect of sulfur dioxide on Swiss albino mice. J Combustion Toxicol 4:236-244.
6. Kinkead ER, Einhaus RL [1984]. Acute toxicity of thionyl chloride vapor for rats. Wright-Patterson Air Force Base, OH: Air Force Systems Command, Air Force Aerospace Medical Division, Aerospace Medical Research Laboratory, Technical Report AFAMRL-TR-84-069.
7. NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 2. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 95-102.
8. Shupe JL, Olson AE, Sharma RP [1972]. Fluoride toxicity in domestic and wild animals. Clin Toxicol 5:195-213.
9. Tab Biol Per [1933]; 3:231 (in German).