Ammonia

 
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:

                                                     Adjusted               
                             LC50   LCLo              0.5-hr          Derived
Species     Reference       (ppm)  (ppm)   Time       LC (CF)          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      2,000  -----   4 hr    5,660 ppm (2.83)    566 ppm
         Gerarde 1969
Mammal   Flury 1928         -----  5,000   5 min   2,050 ppm (0.41)    205 ppm
Mouse    Kapeghian et al.   4,230  -----   1 hr    5,964 ppm (1.41)    596 ppm
         1982 
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.