Ammonia

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] Vapor density = 0.59 (lighter than air); [HSDB]
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] Also used in illicit methamphetamine labs; Anhydrous ammonia is the most commonly reported agent in accidental spill or release incidents. [PMID 19225422]
Comments
Liquid causes first degree burns on short exposure; [CHRIS] Ammonia gas and liquid are corrosive to skin. [Quick CPC] Ingestion of industrial strength ammonia (27-30%) causes esophageal burns with liquefaction necrosis and the possibility of later perforation and stricture formation. Inhalation of concentrated ammonia can cause acute lung injury. Household ammonia (5-10%) is not likely to cause serious burns. [HSDB] "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. 563] The following chemicals can release ammonia when spilled in water: Lithium nitride & Magnesium diamide. Ammonia solutions with more than 50% ammonia are classified as TIH (Toxic Inhalation Hazard). [ERG 2016] Ammonia is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans.
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
Insufficient data
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 (rat) = 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]
NFPA
must be preheated
ERPG-1
25 ppm
ERPG-2
150 ppm
ERPG-3
1500 ppm

Adverse Effects

Chronic Bronchitis
Yes
Toxic Pneumonitis
Yes
Fibrogenic
Yes

Diseases, Processes, and Activities Linked to This Agent

Diseases

Occupational diseases associated with exposure to this agent:

Activities