Anhydrous Ammonia

Anhydrous Ammonia Summary

Expected Concentrations:

Anhydrous ammonia is a relatively volatile chemical that quickly vaporizes at room temperature. For this reason, exposures to anhydrous ammonia can reach extremely high levels, especially if the solution is agitated. Three simulated clandestine cooks using anhydrous ammonia were conducted by National Jewish Medical and Research Center. During the initial cook using the anhydrous ammonia method, the researchers measured levels of anhydrous ammonia that exceeded 3000 ppm in the area of the cook. The average exposure levels in the cook area during the entire period of time that the cook was conducted ranged from 190 ppm to 410 ppm. The exposures in the breathing zone of the individuals conducting the cook ranged from 130 ppm to 370 ppm during the cook. In general, measurements at the cooks range from 500 ppm to 2000 ppm depending upon the stage of the cook and the amount of agitation.

Current standards for anhydrous ammonia exposures are as follows:

OSHA PEL

NIOSH REL

ACGIH TLV

NIOSH IDLH

50 ppm

25 ppm
(Short Term = 35 ppm)

25 ppm
(STEL = 35 ppm)

300 ppm

General Health Effects:

The concentration of ammonia measured during anhydrous ammonia "cooks" can approach or exceeded the Immediately Dangerous to Life and Health Levels (IDLH) published by NIOSH. (1)   Anhydrous ammonia is an extremely irritating compound that poses an inhalation hazard, a dermal hazard, an ingestion hazard, and an ocular and mucous membrane hazard. As a liquid, it is capable of causing skin, eye, and digestive system damage from contact. As a gas, it has a very pungent and suffocating odor that typically drives exposed individuals from the area. It is possible, however, that olfactory fatigue can set in quickly allowing increased exposures to individuals. At concentrations exceeding 50 ppm, individuals may experience nose, throat, eye, mucous membrane, and airway irritation. Extended exposure may cause wheezing, shortness of breath, and chest pain as well as tearing and ocular damage. (2)  Inhalation may also cause burns to the respiratory tract and may result in a chronic bronchitis. Chronic obstructive pulmonary disease may also develop from fibrous obstruction of the smaller always.

Exposure to high levels of anhydrous ammonia (levels exceeding 2500 ppm) have been found to cause severe corneal irritation, difficulty breathing, bronchospasm, chest pain and pulmonary edema in otherwise healthy adults. The pulmonary edema associated with these exposures has been fatal in some instances. Repeated exposure to high levels of anhydrous ammonia may cause chronic cough, bronchitis, asthma, vocal cord dysfunction, reactive airways disease, and lung fibrosis. In some cases, a permanent decrement in pulmonary function has occurred due to anhydrous ammonia exposures. Contact with the liquid state may also cause serious eye injury or blindness as well as skin burns. (3)

The current OSHA Permissible Exposure Level (PEL) is 50 ppm and the ACGIH Threshold Limit Value (TLV) for ammonia is 25 ppm as an eight-hour time-weighted average and 35 ppm as a Short-term exposure level (15 minutes or less no more than 4 times per day). (4,5)  The AIHA Emergency Response Guidelines (6) suggest that most individuals can be exposed to 25 ppm of ammonia for at least one hour without suffering more than mild, transient health effects (ERPG-1). At 150 ppm, most individuals can be exposed for up to one hour without experiencing any irreversible or serious health effects (ERPG - 2). At an exposure level of less than 750 ppm, most individuals could be exposed for up to one hour and not experience any life threatening health effects. The current NIOSH Immediately Dangerous to Life and Health Level (IDLH) is listed as 300 ppm. (1)

Health Risks to Children:

Children with exposures to hydrogen chloride are likely to have similar symptoms as do adults. Children may be more susceptible to pulmonary damage due to a greater lung surface area per body weight and a more rapid breathing rate. The health effects may also be more pronounced due to narrower air passages in the lungs.

Fetal Health Effects:

None Reported.

Supporting Documents

Technical Support Document: Toxicology
Clandestine Drug Labs: Meth
AMMONIA
Office of Environmental Health Hazard Assessment

Ammonia: Fact Sheet
Office of Environmental Health Hazard Assessment

References:

  1. NIOSH. 2005. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 2005-149. Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health. Cincinnati, OH  424 pp.
  2. Salocks, C. and Kaley, K. 2003. Technical Support Document:  Toxicology,  Clandestine Drug Labs:  Methamphetamine. Volume 1, Number 1 Ammonia. Office of Environmental Health Hazard Assessment. Department of Toxic Substances Control. Sacramento, CA. 11 pp.
  3. Proctor, N.H. , Hughes, J.P. 1978. Chemical Hazards of the Workplace. J.B. Lippincott Co. Philadelphia, PA  533 pp.
  4. ACGIH. 2006 TLV’s and BEI’s:  Based on the Documentation of the Threshold Limit Values for Chemical Substances and Physical Agents & Biological Exposure Indices. American Conference of Governmental Hygienists. Cincinnati, OH. 2006. 236 pp.
  5. NIOSH. 2005. NIOSH Pocket Guide to Chemical Hazards. DHHS (NIOSH) Publication No. 2005-149. Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health. Cincinnati, OH  424 pp.
  6. AIHA. 2001. Emergency Response Planning Guidelines and Workplace Environmental Exposure Level Guides Handbook. AIHA  Fairfax, VA. 63 pp.