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Ammonia

General Description

  • Synonyms: Anhydrous ammonia
  • OSHA IMIS Code Number: 0170
  • Chemical Abstracts Service (CAS) Registry Number: 7664-41-7
  • NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: BO0875000
  • Department of Transportation Regulation Number (49 CFR 172.101) and Emergency Response Guidebook: 1005 125 (anhydrous); 2672 154 (10-35% solution); 2073 125 (>35-50% solution); 3318 125 (>50% solution)
  • NIOSH Pocket Guide to Chemical Hazards, Ammonia: Physical description, chemical properties, potentially hazardous incompatibilities, and more

Exposure Limits

Exposure Limit Limit Values HE Codes Health Factors and Target Organs

OSHA Permissible Exposure Limit (PEL) - General Industry
See 29 CFR 1910.1000 Table Z-1

50 ppm
(35 mg/m3) TWA

HE4

Temporary blindness

HE11

Pulmonary edema

HE14

Marked eye, skin, and respiratory irritation

OSHA PEL – Construction Industry
See 29 CFR 1926.55 Appendix A

50 ppm
(35 mg/m3) TWA

HE4

Temporary blindness

HE11

Pulmonary edema

HE14

Marked eye, skin, and respiratory irritation

OSHA PEL – Shipyard Employment
See 29 CFR 1915.1000 Table Z-Shipyards

50 ppm
(35 mg/m3) TWA

HE4

Temporary blindness

HE11

Pulmonary edema

HE14

Marked eye, skin, and respiratory irritation

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL)

25 ppm
(18 mg/m3) TWA

35 ppm
(27 mg/m3) STEL

HE14

Marked eye, skin, and respiratory irritation

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2001)

25 ppm
(17 mg/m3) TWA

35 ppm
(24 mg/m3) STEL

HE14

Marked eye, skin, and respiratory irritation

CAL/OSHA PELs

25 ppm
(18 mg/m3) TWA

35 ppm
(27 mg/m3) STEL

HE14

Marked eye, skin, and respiratory irritation

  • National Toxicology Program (NTP) carcinogenic classification: Not listed
  • International Agency for Research on Cancer (IARC) carcinogenic classification: Not listed
  • U.S. Environmental Protection Agency (EPA) carcinogenic classification: Not listed
  • EPA Inhalation Reference Concentration (RfC): 1x10-1 mg/m3
  • Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Level (MRL): 1.7 ppm (acute); 0.1 ppm (chronic)
  • NIOSH Immediately Dangerous to Life or Health (IDLH) concentration: 300 ppm
  • Notes on Other Potential Health Effects and Hazards
    1. Although ammonia does not meet DOT's definition of a flammable gas, it should be treated as one for precautionary reasons (NIOSH [n.d.]).
    2. Exposure to elevated levels of ammonia can also cause hoarseness, violent coughing, painful breathing, impaired vision/blindness, dyspnea, and cyanosis (NIOSH 1992).
    3. Dermal exposure to liquid ammonia or to concentrated forms of ammonia can lead to cutaneous burns of varying severity. Severe burns can result in the liquefication of tissue and can penetrate deeply, resulting in the need for skin grafts (ATSDR 2004).
    4. Firefighters who were exposed to ammonia had 1.7 times the rate of decline in lung function than non-exposed firefighters over a period of 6 to 10 years (ATSDR 2004).
    5. There have been several reports of occupational asthma after exposure to ammonia-containing aerosols (ATSDR 2004).
    6. Sensitization to several allergens and decreased lung function were found in residents neighboring a concentrated animal feeding operation, where elevated levels of ammonia were emitted. Mean annual ammonia levels varied between 16 and 24 mg/m3 (Schulze et al. 2011).
    7. An occupational study that investigated production workers exposed to ammonia in a soda ash facility established an adjusted NOAEL (HEC) of 2.3 mg/m3 (Holness et al. 1989).

Literature Basis

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Ammonia. 2001.
  • ATSDR: Toxicological Profile for Ammonia (PDF). September 2004.
  • Holness, D.L., J.T. Purdham and J.R. Nethercott: Acute and chronic respiratory effects of occupational exposure to ammonia. Am. Ind. Hyg. Assoc. J. 50: 646-650, 1989.
  • NIOSH: Pocket Guide to Chemical Hazards - Ammonia.
  • NIOSH: Occupational Safety and Health Guideline - Ammonia. 1992.
  • NIOSH/IPCS: International Chemical Safety Cards - Ammonia. March 27, 1998.
  • Schulze, A et al.: Effects on pulmonary health of neighboring residents of concentrated animal feeding operations: exposure assessed using optimized estimation technique. Arch Environ Occup Health. 66(3): 146-154, 2011.

Date Last Revised: 9/6/2012

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method:
  • Sulfuric Acid impregnated Carbon Bead (Supelco ORB0-77 tube or equivalent)
  • maximum volume: 24.0 Liters
  • maximum flow rate: 0.1 L/min TWA
  • maximum volume: 7.5 Liters
  • maximum flow rate: 0.5 L/min STEL
  • current analytical method: Ion Chromatography; IC/Conductivity
  • method reference: OSHA Manual of Analytical Methods (OSHA ID-188)
  • method classification: Fully Validated
On-Site Sampling Techniques/Methods:
  • Detector Tube
  • manufacturer: Gastec
  • model/type: 3La
  • sampling information: 0.5 to 2 strokes
  • upper measurement limit: 200 ppm
  • detection limit: 0.5 ppm
  • overall uncertainty: 16.4% for 5 to 20 ppm, 8.2% for 20 to 100 ppm
  • method reference: on-site air secondary (SEI Certified)
  • Detector Tube
  • manufacturer: Matheson-Kitagawa
  • model/type: 8014-105SC
  • sampling information: follow manufacturer's instructions
  • upper measurement limit: 260 ppm
  • detection limit: approximately 1 ppm
  • overall uncertainty: unknown
  • method reference: on-site air secondary (SEI Certified)
  • Detector Tube
  • manufacturer: Dräger
  • model/type: Ammonia 5/a, order no. CH 20501
  • sampling information: 10 strokes
  • upper measurement limit: 70 ppm
  • detection limit: approximately 1 ppm
  • overall uncertainty: 25%
  • method reference: on-site air secondary (manufacturer)

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