Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Absorption rate - oral (%):
100
Absorption rate - dermal (%):
10

Additional information

Introduction

Butyl glycollate (Polysolvan O,CAS 7397-62-8) is a colourless liquid with a slightly light ester like odour. Chemically, it is an ester of n-butyl alcohol (BA, butanol, CAS 71-36-3) and glycolic acid (GA, CAS 79-14-1), which is also reflected in one of the common chemical name (Glycolic acid-n-butyl ester). The compound has a molecular weight of 132.16 g/mol, is hardly miscible in water (46 g/L at 20 °C) and has a log Pow value of 0.38.

Discussion

No in vitro or in vivo studies are available on toxicokinetics or metabolism of Butyl glycollate (Polysolvan O),if administered orally, dermally or by inhalation.

However, the available data on single or repeated oral administration by gavage of up to 28 days in rats indicated that the compound was well absorbed and distributed. Although the acute oral toxicity was very low (LD50in rats of key study: 4595 mg/kg bw), there was a dose-related increased mortality at and above 4000 mg/kg bw as an indication for systemic uptake and distribution (Scholz and Weigand, 1968). In addition, mild and reversible findings were also observed after repeated application of 1000 mg/kg bw/day in the 28-day study indicating again systemic bioavailability (Hofmann T, Mayer D, Langer KH, 1990).

Based on the physical-chemical properties and especially of the low molecular weight and very low log Pow of 0.38, it is suggested that the uptake and systemic bioavailability of Butyl glycollate (Polysolvan O) after oral exposure is 100%. Based on the wide-spread systemic occurrence of esterases, it is assumed that it is rapidly hydrolyzed to n-butyl alcohol (BA) and glycolic acid (GA). For both compounds, sufficient data on toxicokinetics and metabolism are known available.

With regards to dermal penetration and in case of missing data, the physical chemical properties and especially the log Pow provide valuable information on possible skin penetration behaviour. The log Pow of Butyl glycollate (Polysolvan O) is 0.38, which indicates a hydrophobic behaviour most probably due to the polar structure of the molecule. Compounds with a similar log Pow as e.g. 2-butoxyethanol (BE, butyl glycol, CAS 111-76-2, log Pow 0.81) are known to penetrate sufficiently through the skin. However, BE is chemically an ether, slightly more hydrophobic and therefore will penetrate much better than Butyl glycollate (Polysolvan O). In addition, the log Pow of the breakdown product n-butyl alcohol (BA) is 0.88 and thus in the same order as Butyl glycollate (Polysolvan O), while the other breakdown product glycolic acid (GA) has a log Pow -1.11. BA is known to be readily absorbed through the skin. For GA a comprehensive data base on dermal penetration is available, which indicated that the penetration behaviour depends also on pH and composition of formulation. Generally, the observed skin penetration rates of GA ranged between about 2 – 30%, with higher penetration at lower pH. Finally, considering the slightly acidic physiological skin pH in the range of 5 -6 and with regards to the Log Pow, physical chemical properties and data on its principle metabolites, the dermal penetration of Butyl glycollate (Polysolvan O) is assumed as 10%. With regards to the activity of esterases in the skin as well as systemically in the body, the toxicokinetics and metabolic fate is considered as comparable as after oral intake.

Conclusions

The systemic bioavailability of Butyl glycollate (Polysolvan O) after oral uptake is assumed as 100% with rapid absorption, distribution and elimination based on its physical-chemical properties, low molecular weight and log Pow of 0.38 as well as on data of its principle main metabolites n-butyl alcohol and glycolic acid.

The dermal absorption is suggested to amount to about 10% followed by wide-spread distribution and rapid elimination with regards to the log Pow of Butyl glycollate (Polysolvan O) of 0.38, the data on the hydrolysis products and compounds with comparable log Pows.