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Ammonia

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number: 7664-41-7

NIOSH REL: 25 ppm (18 mg/m3) TWA, 35 ppm (27 mg/m3) STEL

Current OSHA PEL: 50 ppm (35 mg/m3) TWA

1989 OSHA PEL: 35 ppm (27 mg/m3) STEL

1993-1994 ACGIH TLV: 25 ppm (17 mg/m3) TWA, 35 ppm (24 mg/m3) STEL

Description of substance: Colorless gas with a pungent, suffocating odor.

LEL: 15% (10% LEL, 15,000 ppm)

Original (SCP) IDLH: 500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by AIHA [1971] that 300 to 500 ppm for 30 to 60 minutes have been reported as a maximum short exposure tolerance [Henderson and Haggard 1943]. AIHA [1971] also reported that 5,000 to 10,000 ppm are reported to be fatal [Mulder and Van der Zahm 1967] and exposures for 30 minutes to 2,500 to 6,000 ppm are considered dangerous to life [Smyth 1956].

Existing short-term exposure:
1988 American Industrial Hygiene Association (AIHA) Emergency Response Planning Guidelines (ERPGs)

  • ERPG-1: 25 ppm
  • ERPG-2: 200 ppm
  • ERPG-3: 1,000 ppm

National Research Council [NRC 1987] Emergency Exposure Guidance Levels (EEGLs)

  • 1-hour EEGL: 100 ppm
  • 24-hour EEGL: 100 ppm

U.S. Navy Standards [U.S. Bureau of Ships 1962] Maximum allowable concentrations (MACs):

  • Continuous exposure (60 days): 25 ppm
  • 1 hour: 400 ppm

ACUTE TOXICITY DATA

Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hr LC (CF) Derived Value
Rat Alarie 1981 40,300 —– 10 min 23,374 ppm (0.58) 2,337 ppm
Rat Alarie 1981 28,595 —– 20 min 23,448 ppm (0.82) 2,335 ppm
Rat Alarie 1981 20,300 —– 40 min 23,345 ppm (1.15) 2,335 ppm
Rat Alarie 1981 11,590 —– 1 hr 16,342 ppm (1.41) 1,634 ppm
Rat Back et al. 1972 7,338 —– 1 hr 10,347 ppm (1.41) 1,035 ppm
Mouse Back et al. 1972 4,837 —– 1 hr 6,820 ppm (1.41) 682 ppm
Rabbit Boyd et al. 1944 9,859 —– 1 hr 13,901 ppm (1.41) 1,309 ppm
Cat Boyd et al. 1944 9,859 —– 1 hr 13,901 ppm (1.41) 1,309 ppm
Rat Deichmann and Gerarde 1969 2,000 —– 4 hr 5,660 ppm (2.83) 566 ppm
Mammal Flury 1928 —– 5,000 5 min 2,050 ppm (0.41) 205 ppm
Mouse Kapeghian et al. 1982 4,230 —– 1 hr 5,964 ppm (1.41) 596 ppm
Human Tab Biol Per 1933 —– 5,000 5 min 2,050 ppm (0.41) 205 ppm

*Note: Conversion factor (CF) was determined with “n” = 2.0 [ten Berge et al. 1986].

Other animal data:RD50 (mouse), 303 ppm [Appelman et al. 1982].

Other human data: The maximum short exposure tolerance has been reported as being 300 to 500 ppm for 0.5 to 1 hour [Henderson and Haggard 1943]. A change in respiration rate and moderate to severe irritation has been reported in 7 subjects exposed to 500 ppm for 30 minutes [Silverman et al. 1946].

Revised IDLH: 300 ppm
Basis for revised IDLH: The revised IDLH for ammonia is 300 ppm based on acute inhalation toxicity data in humans [Henderson and Haggard 1943; Silverman et al. 1946].

REFERENCES:

  1. AIHA [1971]. Anhydrous ammonia. In: Hygienic guide series. Am Ind Hyg Assoc J 32:139-142.
  2. Alarie Y [1981]. Dose-response analysis in animal studies: prediction of human responses. Environ Health Perspect 42:9-13.
  3. Appelman LM, ten Barge WF, Reuzel PGJ [1982]. Acute inhalation toxicity study of ammonia in rats with variable exposure periods. Am Ind Hyg Assoc J 43:662-665.
  4. 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. A-172 to A-173.
  5. Boyd EM, MacLachlan ML, Perry WF [1944]. Experimental ammonia gas poisoning in rabbits and cats. J Ind Hyg Toxicol 26:29-34.
  6. Deichmann WB, Gerarde HW [1969]. Trifluoroacetic acid (3FA). In: Toxicology of drugs and chemicals. New York, NY: Academic Press, Inc., p. 607.
  7. Flury F [1928]. Moderne gewerbliche vergiftungen in pharmakologisch-toxikologischer hinsicht (Pharmacological-toxicological aspects of intoxicants in modern industry). Arch Exp Pathol Pharmakol 138:65-82 (translated).
  8. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, p. 126.
  9. Kapeghian JC, Jones AB, Mincer HH, Verlangieri AJ, Waters IW [1982]. The toxicity of ammonia gas in the mouse. Fed Proc 41:1568 [Abstract #7586].
  10. Mulder JS, Van der Zahm HO [1967]. Fatal case of ammonium poisoning. Tydschrift Voor Sociale Geneeskunde (Amsterdam) 45:458-460 (translated).
  11. 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. 7-15.
  12. Silverman L, Whittenberger JL, Muller J [1946]. Physiological response of man to ammonia in low concentrations. J Ind Hyg Toxicol 31:74-78.
  13. Smyth HF Jr [1956]. Improved communication: hygienic standards for daily inhalation. Am Ind Hyg Assoc Q 17(2):129-185.
  14. Tab Biol Per [1933]; 3:231-296 (in German).
  15. 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.
  16. U.S. Bureau of Ships [1962]. Submarine atmosphere habitability data book. AVSHIPS 250-649-1. Rev. 1. Washington, DC: U.S. Department of the Navy, U.S. Bureau of Ships, p. 629.
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