An official website of the United States government
Hydrogen chloride
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7647–01–0
NIOSH REL: 5 ppm (7 mg/m3) CEILING
Current OSHA PEL: 5 ppm (7 mg/m3) CEILING
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 5 ppm (7.5 mg/m3) CEILING
Description of Substance: Colorless to slightly yellow gas with a pungent, irritating odor.
LEL:. . Nonflammable Gas
Original (SCP) IDLH: 100 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statements by Patty [1963] that according to Matt [1889] as cited in Flury and Zernik [1931], work is impossible when one inhales air containing hydrogen chloride in concentrations of 75 to 150 mg/m3 (50 to 100 ppm); work is difficult but possible when the air contains concentrations of 15 to 75 mg/m3 (10 to 50 ppm); and work is undisturbed at the concentration of 15 mg/m3 (10 ppm).
Existing short-term exposure guidelines: National Research Council [NRC 1987] Emergency Exposure Guidance Levels (EEGLs) and Short-term Public Emergency Guidance Levels (SPEGLs):
10-minute EEGL: 100 ppm
1-hour EEGL: 20 ppm
24-hour EEGL: 20 ppm
1-hour SPEGL: 1 ppm
24-hour SPEGL: 1 ppm
ACUTE TOXICITY DATA
Lethal concentration data:
| Species | Reference | LC50(ppm) | LCLo(ppm) | Time | Adjusted 0.5-hrLC (CF*) | Derivedvalue |
|---|---|---|---|---|---|---|
| HumanRat
Rabbit G. pig Human Mouse |
Lefaux 1968MacEwen and Vernot 1974
Machle et al. 1942 Machle et al. 1942 Tab Biol Per 1933 Wohlslagel et al. 1976 |
—–3,124
—– —– —– 1,108 |
1,300—–
4,416 4,416 3,000 —– |
30 min1 hr
30 min 30 min 5 min 1 hr |
1,300 ppm (1.0)6,248 ppm (2.0)
4,416 ppm (1.0) 4,416 ppm (1.0) 500 ppm (0.17) 2,216 ppm (2.0) |
130 ppm625 ppm
442 ppm 442 ppm 50 ppm 222 ppm |
*Note: Conversion factor (CF) was determined with “n” = 1.0 [ten Berge et al. 1986].
Other animal data: RD50 (mouse), 309 ppm [Alarie 1981].
Other human data: It has been reported that 50 to 100 ppm for 1 hour is barely tolerable and that 35 ppm causes irritation of the throat [Henderson and Haggard 1943]. It has also been reported that work is impossible at 50 to 100 ppm but is difficult but possible at 10 to 50 ppm [Flury and Zernik 1931].
| Revised IDLH: 50 ppmBasis for revised IDLH: The revised IDLH for hydrogen chloride is 50 ppm based on acute inhalation toxicity data in humans [Flury and Zernik 1931; Henderson and Haggard 1943; Tab Biol Per 1933]. |
REFERENCES:
1. Alarie Y [1981]. Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.
2. Flury F, Zernik F [1931]. Schädliche gase dämpfe, nebel, rauch- und staubarten. Berlin, Germany: Verlag von Julius Springer, p. 128 (in German).
3. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Co., p. 126.
4. Lefaux R [1968]. Practical toxicology of plastics. Cleveland, OH: Chemical Rubber Co., p. 207.
5. MacEwen JD, Vernot EH [1974]. Toxic Hazards Research Unit annual report: 1974. Wright-Patterson Air Force Base, OH: Air Force Systems Command, Aerospace Medical Division, Aerospace Medical Research Laboratory Report, AMRL-TR-74-78.
6. Machle W, Kitzmiller KV, Scott EW, Treon JF [1942]. The effect of the inhalation of hydrogen chloride. J Ind Hyg Toxicol 24:222-225.
7. Matt L [1889]. Doctoral dissertation. Wurzburg, Germany: Julius Maximillian University (in German). [From Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 851.]
8. NRC [1987]. Emergency and continuous exposure guidance levels for selected airborne contaminants. Vol. 7. Ammonia, hydrogen chloride, lithium bromide, and toluene. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 17-30.
9. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 851.
10. Tab Biol Per [1933]; 3:231 (in German).
11. ten Berge WF, Zwart A, Appelman LM [1986]. Concentration-time mortality response relationship of irritant and systematically acting vapours and gases. J Haz Mat 13:301-309.
12. Wohlslagel J, Dipasquale LC, Vernot EH [1976]. Toxicity of solid rocket motor exhaust: effects of Hcl, HF, and alumina on rodents. J Combustion Toxicol 3:61-70.