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] Can cause contact urticaria; [Kanerva 2004, p. 103] 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. 523] 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 2012] 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)

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]

Reference Link

ATSDR Medical Management - Ammonia

Flammability (NFPA)

1: Must be preheated

Adverse Effects
Chronic Bronchitis

Yes

Toxic Pneumonitis

Yes

Fibrogenic

Yes

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

Chemical Information

Search ChemIDplus

Biomedical References

Search PubMed

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure:

Activities

Activities with risk of exposure: