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Bioaccumulation: terrestrial

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Butyl 3,5 -bis(1,1 -dimethylethyl)-4 -hydroxybenzenepropanoate (CAS 52449-44-2): The test substance was degraded in the test species (earthworms) before it could have been accumulated (Schmidt, 2010). Hence, by read across to CAS 52449-44-2, no bioaccumulation in terrestrial organisms is expected for Z72.

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Additional information

The bioaccumulation potential in terrestrial organisms for the substance Butyl 3,5 -bis(1,1 -dimethylethyl)-4 -hydroxybenzenepropanoate (CAS 52449 -44 -2)

was assessed in the earthworm species Eisenia fetida during 21 days of exposure followed by an elimination phase (Schmidt, 2010). The study is based on the Proposal for a New OECD Guideline: Bioaccumulation, Soil Test Using Terrestrial Oligochaetes, First Draft May 2001.The test item was homogeneously mixed into artificial soil at two concentrations: 0.32 mg/kg dry soil and 3.2 mg/kg dry soil. A control group was run in parallel. Adult earthworms were exposed to the treated soils for 21 days (uptake phase). After the uptake phase, the worms were transferred to untreated artificial soil for an additional 21 days (elimination phase). Six samplings were spaced throughout the uptake and elimination phases. The concentrations of the test substance were determined in the artificial soil of both test concentrations and in the worms of the high dose test concentration.The measured concentration, corrected for the recovery in the soils at the start of the uptake phase, was 72 % of the nominal low dose test concentration and 89 % of nominal high dose test concentration. During the uptake phase, the measured concentration of the test item in soil decreased over time. The measured corrected concentrations at the end of the uptake phase (Day 21) were 8 and 11 % of the nominal values at the low dose and the high dose test concentration, respectively. No test item was detected in the worm samples of the high dose test item treatment one day after introduction of the worms (i.e., five days after application) to 21 days after application. Therefore, no samples of the low dose test item treatment were analyzed. The lack of test item detection in the worms was attributed to rapid degradation of the test item within the worms. In conclusion, the test item showed no bioaccumulation potential in earthworms under the conditions of the study. For all the other substances of concern, Benzenepropanoic acid, 3,5 -bis(1,1 -dimethylethyl)-4 -hydroxy-,C7 -9 branched alkyl esters (Z72) and Benzenepropanoic acid 3,5 -bis(1,1 -dimethylethyl)-4 -hydroxy-2 -ethylhexylester (Z77) neither experimental nor predicted data are available.