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Chemical Sampling Information (CSI)
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General Description

Synonym: 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 2012 Emergency Response Guidebook [4 MB PDF, 392 pages]: 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 and Health Effects

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 [2 MB PDF, 269 pages]. 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

Laboratory Sampling/Analytical Method:

  • sampling media: 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:

  • device: 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)

  • device: 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)

  • device: 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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