Chemical Sampling Information
	Isobutyraldehyde
Quick Links General Description Health Factors Monitoring Search    [use word(s)/phrase] Table of Contents 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 General Description Synonyms: Isobutaldehyde; Isobutanal; Isobutyl aldehyde; Isobutyric Aldehyde; Isopropylformaldehyde; Methyl Propanal; 2-Methyl-1-propanol; 2-Methylpropanal; 2-Methylpropionaldehyde; Valine Aldehyde OSHA IMIS Code Number: R237 Chemical Abstracts Service (CAS) Registry Number: 78-84-2 NIOSH, Registry of Toxic Effects (RTECS) Identification Number: NQ4025000 Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 2045 130 [27 KB, PDF] Chemical Description and Physical Properties: colorless liquid with pungent odor molecular formula: C4H8O molecular weight: 72.1 boiling point: 63-64°C flash point: -40°C closed cup; -23.9°C open cup melting point: -65°C vapor pressure: 15.3 kPa @ 20°C Potentially hazardous incompatibilities: very dangerous fire hazard when exposed to heat, flame, or oxidizers - reacts with oxidants, strong reductants and strong bases Health Factors Potential symptoms: Irritation of eyes, skin, nose, throat; cough, sore throat, shortness of breath, labored breathing, pulmonary edema (may be delayed); eye and skin pain, redness, burns; skin blisters; contact dermatitis; loss of vision; INGES. ACUTE: Burning sensation, abdominal cramps; shock or collapse. Health Effects: Irritation-Eyes, Nose, Throat, Skin---Marked (HE14); Pulmonary edema (HE4) Affected organs: Eyes, skin, respiratory system Notes: OSHA does not have a PEL for isobutyraldehyde. Vapor/air mixtures of isobutryaldehyde may be explosive. Isobutyraldehyde occurs naturally in some foods, such as white bread, beer, and chocolate, and it is listed by the FDA as a synthetic flavoring substance that is permitted for direct addition to food for human consumption (21 CFR 172.515). Two-year carcinogenicity studies were negative for cancer, but non-neoplastic nasal lesions were caused at inhaled isobutyraldehyde concentrations of 1000 and 2000 ppm in rats and mice. Higher concentrations (4000 and 8000 ppm) were lethal to some rats and mice in 13-week inhalation studies. Several cytochrome P-450 isozymes have been identified in rabbit liver, which can metabolize isobutyraldehyde to propylene. Date Last Revised: 02/05/2007 Literature Basis: International Chemical Safety Cards (WHO/IPCS/ILO): Isobutyraldehyde. Abdo, K.M., Haseman, J.K. and Nyska, A.: Isobutyraldehyde administered by inhalation (whole body exposure) for up to thirteen weeks or two years was a respiratory tract toxicant but was not carcinogenic in F344/N rats and B6C3F1 mice. Toxicol. Sci. 42(2): 136-151, 1998. Counet, C., Callemien, D., Ouwerx, C. and Collin, S.: Use of gas chromatography-olfactometry to identify key odorant compounds in dark chocolate. Comparison of samples before and after conching. J. Agric. Food Chem. 50(8): 2385-2391, 2002. Pohanish, R.P. (editor): Isobutyraldehyde. In, Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 2. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 1329-1330. Roberts, E.S., Vaz, A.D.N. and Coon, M.J.: Catalysis by cytochrome P-450 of an oxidative reaction in xenobiotic aldehyde metabolism: deformylation with olefin formation. Proc. Natl. Acad. Sci. U.S.A. 88(20): 8963-8966, 1991. Monitoring Methods used by OSHA Laboratory Sampling/Analytical Method: sampling media: Coated XAD-2 Tube (150/75 mg sections, 20/60 mesh); coating is 10% (w/w) 2-(Hydroxymethyl)piperidine analytical solvent: Toluene maximum volume: 5 Liters   maximum flow rate: 0.05 L/min current analytical method: Gas Chromatography; GC/NPD with GC/MS identification method reference: OSHA Modified NIOSH Analytical Method (NIOSH 2539) [255 KB, PDF] method classification: Partially Validated note: OSHA modification is use of GC/NPD in place of GC/FID. This is a screening method and is not quantitative. All Trademarks are the property of their respective owners. Accessibility Assistance: Contact the OSHA Directorate of Science, Technology and Medicine at 202-693-2300 for assistance accessing PDF materials.