Final report on the safety assessment of PPG-12-Buteth-16, PPG-9-Buteth-12, PPG-26-Buteth-26, and PPG-28-Buteth-35
Currently, PPG-12-Buteth-16, PPG-9-Buteth-12, PPG-26 Buteth-26, and PPG-28-Buteth-35 are reported to be used in cosmetic formulations. PPG is the
acronym used by the cosmetics industry for polypropylene glycol. Very little acute toxicity was
seen in rats, mice, and rabbits with oral exposure to various PPG Buteths, Hepatic and renal
lesions were observed in subchronic oral toxicity studies of PPG-24-Buteth-27 and PPG-33-Buteth-
45 in rats. In a chronic feeding study involving rats and one involving dogs, no significantly
different incidence of neoplasms or other lesions were seen with PPG-7-Buteth-10 and PPG-33-
Buteth-45. Acute, shortterm, and subchronic inhalation studies with various PPG Buteths were
negative. Some deaths were seen in acute dermal toxicity studies in rabbits using various PPG
Buteths, but even the surviving animals exhibited erythema, edema, ecchymosis, and desquamation,
Although PPG-24-Buteth-27 produced mild ocular toxicity, mixed results were seen with PPG-26-
Buteth-26, and no irritation with several other PPG Buteths, PPG Buteths produce skin irritation
in animal tests. In two lifetime skin painting studies in mice, PPG-7-Buteth-10 and PPG-33-
Buteth-45 did not induce papillomas or carcinomas. Some evidence was found that PPG-24-Buteth-27
could act as a tumor promotor, but only at high concentrations. Clinical testing of PPG-26-
Buteth-26 produced no skin irritation or sensitization, Because PPG Buteths are butanol-initiated
random linear copolymers, there is a 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 may be inferred that this compound is not found in other PPG Buteths,
Although the available data on skin irritation and sensitization of PPG-26-Buteth-26 were
considered applicable to the larger molecular weight PPG-28-Buteth-35, these data were not
considered applicable to PPG Buteths with molecular weights lower than that of PPG-26- Buteth-26,
Experience suggested to the CIR Expert Panel that lower molecular weight members of a chemical
family can be absorbed through the skin differently compared to higher molecular weight
compounds. Absent any data on the dermal absorption of a low-molecular-weight PPG Buteth, or
actual data on skin irritation and sensitization, it was concluded that the available data are
insufficient to support the safety of PPG-9-Buteth-12 or PPG-12-Buteth-16 in cosmetic products.
Based on the available data, PPG-26-Buteth-26 and PPG-28-Buteth-35 are considered safe as used in
cosmetic products.