CIR Safety Review: The CIR Expert Panel noted that Butylene Glycol can be metabolized and used as a source of calories. The results of acute, subchronic, and chronic oral toxicity studies indicated a low order of toxicity for these glycols. Results of parenteral injection, inhalation, and acute and subchronic cutaneous toxicity studies likewise supported a low order of toxicity. Butylene Glycol caused minimal to mild skin irritation but no evidence of sensitization. The glycols produced mild to severe ocular irritation with Hexylene Glycol producing the most severe irritation.

A number of product formulations containing these glycols at concentrations up to 21.4% have been tested in various human skin irritation and sensitization assays. The degree of irritation produced depended upon the particular product. There was no correlation between the degree of irritation and the concentration of the glycol present in the product. There were no reactions indicative of skin sensitization to these glycols in any skin sensitization assays and no suggestions of phototoxicity or photosensitization.

FDA: Link to Code of Federal Regulations for Butylene Glycol
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...

FDA: Link to Code of Federal Regulations for Hexylene Glycol and Dipropylene Glycol
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...

Butylene Glycol, Hexylene Glycol, Ethoxydiglycol and Dipropylene Glycol may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Directive of the European Union.
Link to the EU Cosmetics Directive:
http://ec.europa.eu/consumers/sectors/cosmetics/documents/di...

Butylene Glycol, Hexylene Glycol and Dipropylene Glycol are aliphatic diols that function as solvents and viscosity decreasing agents in cosmetics and personal care products. Ethoxydiglycol, the ethyl ether of diethylene glycol, contains only one hydroxyl group. It also functions as a solvent and viscosity decreasing agent.