Fatty acids, C18-unsatd., dimers, compds. with coco alkylamines

Endpoint summary

Additional information

If data forFatty acid C18- unsat, dimer compd. with coco alkylamineare compared with data for the individual components certain prominent features become obvious, which can be explained by the structureand which may have an impact on the further consideration of the substance in the environment.

 

The substanceFatty acids C18- unsat, dimers compd. with coco alkylamine is the salt of the components Fatty acids C18-unsat, dimers (C36) and coco alkylamine (CAS:61788-46-3). Fatty acids C18-unsat, dimers (C36) itself consists of 2 molecules Fatty acid C18-unsat, dimer (C18) (CAS: 61788-89-4). OnceFatty acids C18- unsat, dimers compd. with coco alkylamineis entering the aquatic environment it is expected that the substance with a surplus of water molecules dissociates into its two main components -Fatty acids C18- unsat, dimers (C36) and coco alkylamine. Based on this assumption the substance Fatty acids C18- unsat, dimers compd. with coco alkylamine will partly be evaluated on its both components with regard to its behaviour in the environment.

 

Available data for the Fatty acid C18- unsat, dimer compd. with coco alkylamine:

3 biodegradation studies are available for Fatty acids C18- unsat, dimers compd. with coco alkylamine: In a Manometric Respirometry Test (OECD 301F) the test item reached a biode-gradeation rate of 27% based on CO2 after 28d. In a second study an enhanced CO2-Head-space test (OECD 310) covering a period of 60 days, the test item reached a biodegradation rate of 27% based on CO2 after 28d and 39 % based on CO2 after 60d. In a third study, a BODIS test (ISO10708), the test item reached a biodegradation rate of 40% based on THOD after 28d.

 

Available data for the components:

 

Coco alkylamine:

Coco alkylamine is found to be readily biodegradable but failling the 10d- window under OECD 301 screening conditions. In an EU Risk assessment of primary alkylamines (Draft) it is concluded, that in the majority of the tests the pass level for ready biodegradability (60% CO2 evolution or O2 consumption) was reached within the test period (generally 28 days), but not within the 10-days window…. Based on the results of all tests the primary alkyl amines could be classified as “readily degradable, but failing the 10-days window”.

These findings are supported by Biowin vs. 4.10 calculations for the main C-chain component (C12) and the highest C-chain component (C18) of the coco alkylamine, all indicating that coco alkylamine is readily biodegradable.

 

Fatty acids C18- unsat, dimers (C36):

Fatty acids C18-unsat, dimers (C36) consist of 2 molecules Fatty acid C18-unsat, dimer. Fatty acids C18-unsat, dimers (C36) are not readily biodegradable under OECD 301 screening conditions. Different groups of fatty acids dimers were analysed for biodegradation by the HPV consortium “Fatty acids dimers and Trimers”. The biodegradation data show that none of these substances are substantially biodegradable in the environment with degradation rates of < 10% CO2. These findings are also supported by an ISO 10708 BODIS-Test, a biodegradation test for insoluble substances. The biodegradation rate for Fatty acids C18-unsat, dimers (C36) was found to be <17% ThOD. Based on the available information it is concluded that Fatty acids C18- unsat, dimers are not biodegradable.

 

 

Overall conclusion for Fatty acid C18- unsat, dimer compd. with coco alkylamine:

Comparing the test results ofFatty acid C18- unsat, dimer compd. with coco alkylaminefrom the biodegradation tests with test results for coco alkylamine on the one hand and with test results forFatty acids C18- unsat, dimerson the other hand is justified to conclude that biodegraded part of theFatty acidsC18 unsat compd. with coco alkylamine is the cocoalkylamine, whereas the poorly biodegraded part consists of theFatty acid C18- unsat, dimer (C36).

 

The conclusion that the coco alkyl part is readily biodegradable whereas theFatty acid C18- unsat, dimer (C36) is not, may trigger also further investigation on biodegradation:

 

Biodegradation in water and sediment: simulation tests

In accordance with column 2 of REACH Annex IX, the simulation testing on ultimate degradation in surface waters and sediment simulation testing does not need to be conducted if the substance is readily biodegradable or highly insoluble in water. As the substance is the salt of two components which are expected dissociate in water, both components are considered separately. One component (coco alkylamine) is readily biodegradable, the other (Fatty acid C18- unsat, dimer (C36)) is highly insoluble in water.

 

Biodegradation in soil

In accordance with column 2 of REACH annex IX, further degradation testing does not need to be conducted as the chemical safety assessment does not indicate a need for further investigation.This holds true for the component Fatty acid C18- unsat, dimer (C36).

 

Coco alkylamine is readily biodegradable. In Annex IX column 2 of the Regulation (EC) No 1907/2006 REACH concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), it is suggested, that a study on "soil simulation testing" does not need to be conducted if "the substance is readily biodegradable”.