AMMONIA | Occupational Safety and Health Administration

AMMONIA†

Chemical Identification
CAS #	7664-41-7
Formula	NH₃
Synonyms	anhydrous ammonia, aqua ammonia

Physical Properties
Physical description	Colorless gas with a pungent, suffocating odor. Often used in aqueous solution.
Boiling point	-28°F	Molecular weight	17
Freezing point/melting point	-107.9°F	Vapor pressure	8.5 atm
Flash point		Vapor density	0.6
Specific gravity	0.6818 at -28.03°F	Ionization potential	10.18 eV
Lower explosive limit (LEL)	15%	Upper explosive limit (UEL)	28%
NFPA health rating	3	NFPA fire rating	1
NFPA reactivity rating	0	NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.)	0170
Sampling group
Sampler/Sampling media	Sulfuric acid impregnated carbon bead tube [Supelco 20036]
Sampling time^*	240 min
Sampling volume (TWA)^*	24 L
Sampling flow rate (TWA)^*	0.1 L/min
Sampling volume (STEL/Peak/C)^*	7.5 L
Sampling flow rate (STEL/Peak/C)^*	0.5 L/min
Analytical method instruments	IC
Method reference	OSHA ID-188 (fully validated)
Notes	Known interferences with the ammonium ion by IC with the current conditions: Methyl- and dimethylamine, mono- and diethanolamine, iso- and propanolamine
Special requirements

^* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Bulk/Wipe Method
Wipe Sampler/Sampling media
Bulk Method

On-Site Screening Techniques
Device	Detector tube	Detector tube	Detector tube	CMS Chip	CMS Chip	CMS Chip
Model/Type	Gastec 3LA	Matheson-Kitagawa 8014-105SC	Dräger - Ammonia 5/a, CH20501	Ammonia, 0.2-5 ppm range; Ammonia, 2-50 ppm range	Ammonia, 10-150 ppm range	Ammonia, 100-2000 ppm range
Sampling information (see manufacturer instructions)	0.5-2 strokes, 0.5-200 ppm range, 16.4% for 5-20 ppm, 8.2%; for 20-100 ppm uncertainty	10-260 ppm range, follow mfr instructions	10 strokes, 1-70 ppm range, 25% uncertainty

**Exposure Limits**
OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak		NIOSH REL Up to 10-hour TWA (ST) STEL (C) Ceiling		ACGIH TLV© 8-hour TWA (ST) STEL (C) Ceiling		CAL/OSHA PEL 8-hour TWA (ST) STEL (C) Ceiling Peak
PEL-TWA	50 ppm (35 mg/m³)	REL-TWA	25 ppm (18 mg/m³)	TLV-TWA		PEL-TWA	25 ppm (17 mg/m³)
PEL-STEL		REL-STEL	35 ppm (27 mg/m³)	TLV-STEL		PEL-STEL	35 ppm (27 mg/m³)
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	N	Skin notation	N	Skin notation	N	Skin notation	N
Notes: See 29 CFR 1910.1000 Table Z-1.		Notes:		Notes: Visit the ACGIH TLV site for specific data		Notes:
Health factors: See NIH-NLM PubChem.		IDLH	300 ppm
Carcinogenic classifications: Not listed		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3: 25 ppm/150 ppm/1500 ppm

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Ammonia

NIOSH: Pocket Guide to Chemical Hazards - Ammonia

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Ammonia. See annual publication for most recent information.
ATSDR: Toxicological Profile for Ammonia. 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: Occupational Safety and Health Guideline for Ammonia. 1992.
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.

Last Updated Date : 03/28/2024

AMMONIA†

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References