Polypropylene Glycol (PPG) Buteths (PPG-12-Buteth-16, PPG-9-Buteth-12, PPG-26-Buteth-26, PPG-28-Buteth-35) are colorless or pale yellow, transparent liquids. In cosmetics and personal care products, PPG Buteth ingredients are used in the formulation of bubble baths and other bath products, shampoos and other hair products, skin fresheners, skin cleansers, and shaving products.
The safety of the PPG Buteth ingredients has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel (CIREP). The CIR Expert Panel evaluated the scientific data and concluded that PPG-9-Buteth-12, PPG-12-Buteth-16, PPG-26-Buteth-26 and PPG-28-Buteth-35 were safe as used in cosmetics and personal care products.
CIR Safety Review: Very little acute toxicity was seen after oral exposure to various PPG Buteth ingredients. Acute, short-term, and subchronic inhalation studies with various PPG Buteths were negative as well. Hepatic and renal lesions were observed in subchronic oral toxicity studies of PPG-24-Buteth-27 and PPG-33-Buteth-45. In chronic feeding studies, no significantly different incidences of neoplasms or other lesions were seen with PPG-7-Buteth-10 and PPG-33-Buteth-45. While PPG-24-Buteth-27 produced mild ocular toxicity, mixed results were seen with PPG-26-Buteth-26, and no irritation was observed with several other PPG Buteths. PPG Buteth ingredients produced skin irritation in some tests. In two lifetime skin painting studies, PPG-7-Buteth-10 and PPG-33-Buteth-45 did not induce papillomas or carcinomas.
Clinical testing of PPG-26-Buteth-26 produced no skin irritation or sensitization. Clinical testing of PPG-12-Buteth-16 likewise produced no skin irritation or sensitization. Based on its large molecular weight alone, it is unlikely that PPG-28-Buteth-35 would be associated with any skin irritation or sensitization. PPG-9-Buteth-12 has a lower molecular weight than the PPG Buteths for which there has been shown an absence of skin sensitization and irritation, but it is highly soluble in water and has a molecular weight over 1000. These factors suggest that skin absorption would be very limited and it would be unlikely that PPG-9-Buteth-12 would produce skin irritation or sensitization. Because PPG Buteths are butanol-initiated random linear copolymers, there was concern that a reproductive and developmental toxin, n-butyl alcohol, could be present. Data were provided showing the absence of n-butyl alcohol in PPG-26-Buteth-26 from which it was inferred that this compound is not found in other PPG Buteths.
Small amounts of 1,4-dioxane, a by-product of ethoxylation, may be found in the PPG Buteth ingredients. The potential presence of this material is well known and can be controlled through purification steps to remove it from the ingredients before blending into cosmetic formulations.
Link to more information about what the Food and Drug Administration (FDA) is doing to assure that cosmetics do not contain unsafe levels of 1,4-dioxane.
http://www.cfsan.fda.gov/~dms/cosdiox.html
Link to FDA Code of Federal Regulations for Poly (oxyethylene/oxypropylene)monobutylether (PPG Buteths)
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
PPG Buteths 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/enterprise/cosmetics/html/consolidated_d...