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The biodegradability of Butanedioic acid, 2,3-dihydroxy- [R-(R*,R*)]-, C12-13-branched alkyl esters was assessed in a CO2 -evolution test according to the OECD 301B guideline (July 1992). The degradation extent of the test item was 64.2 % within 35 days after acidification. The degradation after 28 days was 54.0%. According to the Revised Introduction to the OECD Guidelines for Testing of Chemicals, Section 3 the test item can be classified as inherently biodegradable.

The BCFBAF version 3.01 programme of the EPI Suite software (v 4.10) was used to predict either a log BCF of 2.19 (BCF of 153 L/kg wet-wt) (linear C12 -component), 2.26 (BCF 181 L/kg wet-wet) (branched C12 -component), 1.78 (BCF 59.7 L/kg wet-wt) based on a regression estimate or a log BAF of - 0.01 (BAF of 0.966 L/kg wet-wt) (linear C12 -component), log BAF -0.01 (BAF = 0.972 L/kg wet-wt) (branched C12 - component), log BAF -0.04 (BAF = 0.91 L/kg wet-wt) (branched C13 - component) based on the Arnot-Gobas upper trophic model both using the smiles codes of Butanedioic acid, 2,3 -dihydroxy-[R-(R*,R*)]-C12 -linear alkyl esters, Butanedioic acid, 2,3 -dihydroxy-[R-(R*,R*)]-C12 -branched alkyl esters and Butanedioic acid, 2,3 -dihydroxy-[R-(R*,R*)]-C13 -branched alkyl ester representing Butanedioic acid, 2,3 -dihydroxy-[R-(R*,R*)]-C12 -13 -branched alkyl ester. Because the Arnot-Gobas upper trophic model takes also into account metabolism of the substance by the organism it is lower. The QSAR-data are supported by the results of the pharmacokinetics. Butanedioic acid, 2,3 -dihydroxy-[R-(R*,R*)]-C12 -13 -branched alkyl esters will be hydrolysed, absorbed and efficiently metabolised into water soluble metabolites, which is supported by the molecular structure of Butanedioic acid, 2,3 -dihydroxy-[R-(R*,R*)]-C12 -13 -branched alkyl esters and its physico-chemical properties.

The log Kocs of the test substance were estimated with the program US EPA EPI Suite (v 4.10), program component KOCWIN (v 2.00). Using a correlation based on molecular connectivity index, the log Koc were determined to be 3.8619 - 4.3832. Using a correlation based on Kow, the log Koc was 5.2755 and 5.8176. The high Koc values indicate a distinct potential of the test substance to accumulate in soil and sediment.The McCall classification scheme classifies the substances as immobile in soil (Koc > 5000).

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