US Dept of Labor

Occupational Safety & Health AdministrationWe Can Help

Butyric acid

General Description

  • Synonyms: Butanic acid; n-Butanoic Acid; Ethylacetic Acid; 1-Propanecarboxylic acid; Propylformic Acid
  • OSHA IMIS Code Number: B709
  • Chemical Abstracts Service (CAS) Registry Number: 107-92-6
  • NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: ES5425000
  • Chemical Description and Physical Properties:
    • colorless oily liquid, with characteristic odor
    • molecular weight: 88.12
    • vapor pressure: 57 Pa at 20°C
    • molecular formula: C4H8O2
    • boiling point: 164°C
    • melting point: -7.9°C
    • flash point: 72°C closed cup

Health Factors

  • Potential Symptoms: Irritation of eyes, skin, throat; skin redness, pain, burns, blisters (from contact with liquid); cough, shortness of breath, labored breathing; eye redness, pain, burns, loss of vision (from liquid); Acute ingestion: Burning sensation, abdominal pain; shock or collapse.
  • Health Effects: Irritation-Eyes, Nose, Throat, Skin---Marked (HE14)
  • Affected Organs: Eyes, skin, respiratory system
  • Notes:
    1. OSHA does not have a PEL for butyric acid.
    2. Explosive vapor/air mixtures of butyric acid may be formed at temperatures above 72°C.
    3. Butyric acid is listed by the FDA as a synthetic flavoring substance that is generally recognized as safe (GRAS) for its intended use (21 CFR 182.60).
    4. NIOSH reported butyric acid to be among the prominent volatile organic compounds (VOC) found in a commercial paste form of butter flavoring when heated to 50°C. VOC from butter flavorings have been causally implicated in occupational lung disease, including bronchiolitis obliterans (see also Diacetyl). However, no information was found regarding the health effects of chronic low-level inhalational exposure to butyric acid.
    5. Butyric acid is a potent uncompetitive inhibitor of human diacetyl reductase (IC50, 64 µM), a ubiquitous enzyme that has the capability of detoxifying diacetyl.
  • Literature Basis:
    • International Chemical Safety Cards (WHO/IPCS/ILO): Butyric acid.
    • Boylstein, R., Piacitelli, C., Grote, A., Kanwal, R., Kullman, G. and Kreiss, K.: Diacetyl emissions and airborne dust from butter flavorings used in microwave popcorn production. J. Occup. Environ. Hyg. 3(10): 530-535, 2006.
    • Nakagawa, J., et al.: Molecular characterization of mammalian dicarbonyl/L-xylulose reductase and its localization in kidney. J. Biol. Chem. 277(20): 17883-17891, 2002.
    • Pohanish, R.P. (editor): Butyric Acid. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 429-431.
  • Date Last Revised: 05/02/2007

Monitoring Methods used by OSHA

Primary Laboratory Sampling/Analytical Method (SLC1):
  • Silica Gel Tube (520/260 mg sections; 20/40 mesh)
  • maximum volume: 18 Liters
  • maximum flow rate: 0.1 L/min
  • current analytical method: Gas Chromatography; GC/FID
  • analytical solvent: (1:99) Formic Acid:Water
  • method reference: OSHA Salt Lake Technical (SLTC) Center In-House File
  • method classification: Not Validated
Articles:

Gilland, James C.; Johnson, Gary T.; McGee, William A. American Industrial Hygiene Association Journal Vol 42, 8, 630-2

** All Trademarks are the property of their respective owners.

Search Chemical Sampling Information

Index

By Name

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

By CAS Number
collage image - OSHA Salt Lake Technical Center
Back to Top

Thank You for Visiting Our Website

You are exiting the Department of Labor's Web server.

The Department of Labor does not endorse, takes no responsibility for, and exercises no control over the linked organization or its views, or contents, nor does it vouch for the accuracy or accessibility of the information contained on the destination server. The Department of Labor also cannot authorize the use of copyrighted materials contained in linked Web sites. Users must request such authorization from the sponsor of the linked Web site. Thank you for visiting our site. Please click the button below to continue.

Close