The Food and Drug Administration (FDA) permits butylene glycol to be used as a synthetic flavoring and adjuvant for direct addition to food. Butylene glycol, hexylene glycol and dipropylene glycol are allowed to be used as indirect food additives. For example, butylene glcyol may be used in polymeric coatings in contact with food, and hexylene glycol and dipropylene glycol may be used in adhesives in contact with food.
The safety of butylene glycol and related ingredients has been assessed by the Expert Panel on Ingredient Safety. The Expert Panel evaluated the scientific data and concluded that butylene glycol, hexylene glycol, ethoxydiglycol and dipropylene glycol are safe for use in cosmetics and personal care products.
In 2004, the Expert Panel considered available new data on butylene glycol and the related ingredients and reaffirmed the above conclusion.
The 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 Code of Federal Regulations for butylene glycol
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 Regulation of the European Union.