PROPIONIC ACID

Chemical Identification
CAS #	79-09-4
Formula	C₃H₆O₂
Synonyms	carboxyethane; ethanecarboxylic acid; ethylformic acid; metacetonic acid; methyl acetic acid

Physical Properties
Physical description	Colorless, oily liquid with a pungent, disagreeable, rancid odor.
Boiling point	286°F	Molecular weight	74.1
Freezing point/melting point	-6.7°F	Vapor pressure	3 mmHg
Flash point	126°F	Vapor density	2.56
Specific gravity	0.99	Ionization potential	10.24 eV
Lower explosive limit (LEL)	2.9%	Upper explosive limit (UEL)	14.8%
NFPA health rating	3	NFPA fire rating	2
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.)	2168
Sampling group
Sampler/Sampling media	Silica gel tube (520/260 mg) [SKC 226-15]
Sampling time^*	90 min
Sampling volume (TWA)^*	18 L
Sampling flow rate (TWA)^*	2 L/min
Sampling volume (STEL/Peak/C)^*
Sampling flow rate (STEL/Peak/C)^*
Analytical method instruments	IC
Method reference	OSHA PV2293 (partially validated)
Notes
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
Model/Type
Sampling information (see manufacturer instructions)

**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		REL-TWA	10 ppm (30 mg/m³)	TLV-TWA	10 ppm [1977]	PEL-TWA	10 ppm (30 mg/m³)
PEL-STEL		REL-STEL	15 ppm (45 mg/m³)	TLV-STEL		PEL-STEL
PEL-C		REL-C		TLV-C		PEL-C
Skin notation	NA	Skin notation	N	Skin notation	N	Skin notation	N
Notes: Not established		Notes:		Notes:		Notes:
Health factors: See NIH-NLM PubChem.		IDLH
Carcinogenic classifications: Not listed		Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:

Additional Resources and Literature References

NOAA: CAMEO Chemicals - Propionic acid

NIOSH: Pocket Guide to Chemical Hazards - Propionic acid

Literature References

ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Propionic acid. See annual publication for most recent information.
Harrison, P.T.: Propionic acid and the phenomenon of rodent forestomach tumorigenesis: a review. Food Chem. Toxicol. 30(4): 333-340, 1992.
Henschel, R., Agathos, M. and Breit, R.: Acute irritant contact dermatitis from propionic acid used in animal feed preservation. Contact Dermatitis 40(6): 328, 1999.
Lehnert, W., Sperl, W., Suormala, T. and Baumgartner, E.R.: Propionic academia: clinical, biochemical and therapeutic aspects. Experience in 30 patients. Eur. J. Pediatr. 153(7 Suppl. 1): S-68-S80.
Pohanish, R.P. (editor): Propionic Acid. In, Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1955-1957.
Walker, J.C., Kendal-Reed, M., Hall, S.B., Morgan, W.T., Polyakov, V.V. and Lutz, R.W.: Human responses to propionic acid. II. Quantification of breathing responses and their relationship to perception. Chem. Senses 26(4): 351-358, 2001.

Last Updated Date : 01/08/2021

PROPIONIC ACID

Chemical Identification

Physical Properties

Monitoring Methods Used by OSHA

Bulk/Wipe Method

On-Site Screening Techniques

Exposure Limits

Additional Resources and Literature References