Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The registered substance, (-)-(3aR,5aS,9aS,9bR)-3a,6,6,9a-Tetramethyldodecahydronaphtho[2,1-b]furan, contains no organic functional groups that may hydrolyse under environmental condition like alkyl halides, amides, amines, epoxides, esters. This substance consists only of organic functional groups that are relatively or completely inert with respect of hydrolysis. Based on the chemical structure an estimation of the hydrolysis rate is not possible. This statement is supported by one study showing that the registered substance is hydrolytically stable under the conditions of the test (the disappearance of the substance after 5 days as well as after 28 days is less than 10% at any pH (from 2 to 12) at 40°C). Therefore, the registered substance is assumed to be hydrolytically stable under the study conditions of the OECD 111 test guideline at pH 4, 7 and 9.

Based on the key biodegradation study, the registered substance is readily biodegradable and therefore is not considered persistent in the environment. Finally, based on data on a source substance (which is the racemic form of the registered substance), (±)-(3aR*,5aS*,9aS*,9bR*)-3a,6,6,9a-Tetramethyldodecahydronaphtho[2,1-b]furan , the adsorption coefficient (Koc) of the registered substance can be determined at 5250, corresponding to a log Koc at 3.72. Based on structural similarity and common physico-chemical properties between these isomers, this source substance is considered adequate for read-across purposes (see IUCLID section 13 for justification). The result indicates that the registered substance is environmentally immobile in soils, according to P.J. McCall et al., 1980. Indeed, given the high log Kow value (5.09) and log Koc value, this is theoretically high adsorption to sewage sludge, which is then transferable to soil, and adsorption to sediment. However, according to the ready biodegradability study, the substance will already be biodegraded in the Sewage Treatment Plant (STP) prior to dispersion into the environment. In addition to the metabolism by bacteria, the substance is metabolised by higher vertebrates (liver activity). Indeed, the results of the combined repeated dose toxicity with the reproduction/developmental screening test repeated oral toxicity study in the rat performed on the racemate form of the registered substance (EC# 223 -118 -6) showed liver changes that are consistent with the increased metabolism associated with detoxification of a xenobiotic. Moreover, the liver induction suggests that a limited amount of the test substance can be absorbed in the gastrointestinal tract. Therefore, the same metabolism pathway is expected to be followed for the registered substance.

In conclusion, no exposure of aquatic and terrestrial organisms are expected.

Additional information