Agent Name |
Ammonia |
CAS Number |
7664-41-7 |
Formula |
H3-N |
Major Category |
Toxic Gases & Vapors |
Synonyms |
Anhydrous ammonia; Aqua ammonia; Aqueous ammonia [Note: Often used in an aqueous solution.] [NIOSH] UN1005 |
Category |
Corrosive Gases |
Description |
Colorless gas with a pungent, suffocating odor. [Note: Shipped as a liquefied compressed gas. Easily liquefied under pressure.] [NIOSH] |
Sources/Uses |
"About 80% is used in fertilizers; it also is used as a refrigerant gas, and in the manufacture of plastics, explosives, pesticides, detergents, and other chemicals. Small amounts of ammonia occur naturally from decomposition of organic matter." [ATSDR Medical Management] |
Comments |
Liquid causes first degree burns on short exposure; [CHRIS] Ammonia gas and liquid are corrosive to skin. [Quick CPC] Can cause contact urticaria; [Kanerva 2004, p. 103] "The concentration of aqueous ammonia solutions for household use is typically 5% to 10% (weight:volume), but solutions for commercial use may be 25% (weight:volume) or more and are corrosive." [ATSDR Medical Management] Listed as one of "major irritant airborne toxicants"; [LaDou, p. 523] The following chemicals can release ammonia when spilled in water: Lithium amide, Lithium nitride & Magnesium diamide. Ammonia solutions with more than 50% ammonia are classified as TIH (Toxic Inhalation Hazard). [ERG 2008] Ammonia is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans. |
Reference Link |
OSHA Technical Links: Ammonia Refrigeration |
Exposure Assessment |
Skin Designation (ACGIH) |
No |
TIH |
Yes |
TLV (ACGIH) |
25 ppm |
STEL (ACGIH) |
35 ppm |
PEL (OSHA) |
50 ppm |
MAK |
20 ppm |
IDLH (NIOSH) |
300 ppm |
Excerpts from Documentation for IDLHs |
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]. |
Odor Threshold Low |
0.04 ppm |
Odor Threshold High |
53 ppm |
RD50 |
303 ppm |
Lethal Concentration |
LC50 (rats) = 2,000 ppm/4H |
Explanatory Notes |
Detection odor threshold from AIHA (mean = 17 ppm); The Guide from the Emergency Response Guidebook is for "Anhydrous ammonia" or "Ammonia solution, with more than 50% Ammonia." |
Half Life |
Whole body (following ingestion): 1-2 days; [TDR, p. 88] |
Reference Link |
ATSDR - Medical Management Guidelines |
Flammability (NFPA) |
1: must be preheated |
Adverse Effects |
Toxic Pneumonitis |
Yes |
Fibrogenic |
Yes |
Chronic Bronchitis |
Yes |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: AMMONIA
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