Chemical Sampling Information
	n-Butyl Lactate
Quick Links General Description Exposure Limits 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: Butyl alpha-hydroxypropionate; Butyl ester of 2-hydroxypropanoic acid; Butyl ester of lactic acid; Butyl lactate OSHA IMIS Code Number: 0478 Chemical Abstracts Service (CAS) Registry Number: 138-22-7 NIOSH, Registry of Toxic Effects (RTECS) Identification Number: OD4025000 Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1993 128 [27 KB, PDF] (combustible liquid, n.o.s.) NIOSH Pocket Guide to Chemical Hazards, n-Butyl lactate: chemical description, physical properties, potentially hazardous incompatibilities, and more Exposure Limits American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 5 ppm, 30 mg/m3 TWA National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 5 ppm, 25 mg/m3 TWA Health Factors Potential symptoms: Irritation of eyes, skin, nose, throat; cough, headache, drowsiness, CNS depression; nausea, vomiting. Health Effects: Irritation-Eye, Nose, Throat---Moderate (HE15); Headache (HE7) Affected organs: Eyes, skin, respiratory system, CNS Notes: OSHA does not have a PEL for n-butyl lactate. n-Butyl lactate is listed among FDA’s “food additives permitted for direct addition to food for human consumption” (21 CFR 172.515). n-Butyl lactate is metabolized in the body to lactic acid and sequentially to n-butanol, n-butyraldehyde, and n-butyric acid. Irritation is likely due to the lactic acid, which is metabolized to pyruvic acid and subsequently to CO2 during energy production. Butyric acid is a substrate for fatty acid synthesis via medium chain acyl-CoA synthetase. The odor and odor-nuisance thresholds of n-butyl lactate have been reported to be 0.095 and 9 mg/m3, respectively. Subacute (28-day) inhalation studies in rats indicated a NOAEL for n-butyl lactate of 200 mg/m3 (~33 ppm), with higher concentrations causing mild hyperplasia of nasal epithelium. Date Last Revised: 02/07/2007 Literature Basis: NIOSH Pocket Guide to Chemical Hazards: n-Butyl lactate. Clary, J.J., Feron, V.J. and van Velthuijsen, J.A.: Safety assessment of lactate esters. Regul. Toxicol. Pharmacol. 27(2): 88-97, 1998. Pohanish, R.P. (editor): Butyl Lactate. In, Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 416-418. Teeguarden, J.G., et al.: Derivation of a human equivalent concentration for n-butanol using a physiologically based pharmacokinetic model for n-butyl acetate and metabolites n-butanol and n-butyric acid. Toxicol. Sci. 85(1): 429-446, 2005. Monitoring Methods used by OSHA Laboratory Sampling/Analytical Method: sampling media: Charcoal Tube (100/50 mg sections, 20/40 mesh) analytical solvent: (95:5) Methylene Chloride:Methanol maximum volume: 10 Liters   maximum flow rate: 0.2 L/min current analytical method: Gas Chromatography; GC/FID method reference: OSHA Analytical Method (OSHA PV2080) method classification: Partially Validated 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.