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

Bioaccumulation: aquatic / sediment

Description of key information

The substance Fatty 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). BCF values are estimated for the two  main components . Therefore the BCF values for Cocoalkylamine and Fatty acids C18- unsat, dimers (C36) are estimated. The highest BCF was estimated for a substructure of Coco alylamine to be 886L/Kg w.w., whereas Fatty acids C18- unsat, dimers (C36) revealed no bioaccumulation potential (BCF: 3.162).

Key value for chemical safety assessment

BCF (aquatic species):

886 L/kg ww

Additional information

Fatty acid C18- unsat, dimer compd. with coco alkylamine

The substance Fatty 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). Once Fatty acids C18-unsat, dimers compd. with coco alkylamine is entering the aquatic environment it is expected that the substance with a great surplus of water molecules dissociates into its two main components Fatty acids C18- unsat, dimers (C36) and coco alkylamine. Based on this assumption it is justified to evaluate both components with regard to their behavior in the environment individually.

 

Coco alkylamine:

No bioaccumulation data are available for the Coco alkylamine. However, data are available in fish for a related member of the alkyamine family- Hexadecylamine. In a summarizing RAC opinion (2011) for Cocoalkyl amine, BCF values between 200 and 2400 are discussed, however, in the final conclusion a value of 500 L/kg or slightly higher is assumed.

Additionally, in a weight of evidence approach calculations for Coco alkylamine were performed. For components of Coco alkylamine estimations were performed using 3 different QSAR models, Catalogic vs. 5.11.9 (base-line model 2.05), the BCFBAF vs.3.01 using the “regression-base model” and the “Arnot-Gobas model for upper trophic” taking into account metabolism.

 

Catalogic vs. 5.11.9 (Base line model 2.05):

BCF estimations were modeled by Catalogic vs. 5.11.9 (Base line model 2.05) for the main component of coco alkylamine, Dodecylamine (C12), and the component with the longest C-chain, Octadecyl-amine (C18). The model takes into account the influence of mitigating factors like ionization of the molecule, water solubility, size and metabolism. The molecular size was calculated to be in a range of 14.7 – 17.8Å. Based on the estimations for the two components of coco alkylamine with BCF values in the range of 539-753 L/kg, it is concluded that Coco alkylamine has a limited potential to bioaccumulate in organism.

 

EPISuite v4.1/BCFBAFv3.01: The BCF was estimated to be in a range of 27-1510 L/kg (Log BCF: 1.44-3) based on the regression-based method whereas the BCF estimation based on Arnot-Gobas upper trophic predict a BCF of 549-886 L/kg (Log BCF: 2.74-2.94) for the uncharged molecule. Metabolism in fish was predicted to produce 4 types of primary metabolites. 

 

For the ionic molecule of coco alkylamine EPISuite v4.1/BCFBAFv3.01 predicts a BCF in the range of 3.16- 56 L/kg, indicating a low bioaccumulation rate. Coco alkyl amine is covered by the applicability domain.

 

CONCLUSIONS

The used models predicted a limited bioaccumulation potential in organisms. In a weight of evidence it is concluded that Coco alkylamine has a low to moderate bioaccumulation potential, but a classification with regard to bioaccumulation in terms of the PBT-assessment is not necessary. This conclusion in line with the findings for the BCF in fish for hexadecylamine of the RAC opinion.

 

 

Fatty acids C18-unsat, dimers (C36)

EPISuite v4.1/BCFBAFv3.01:BCF estimations using BCFBAF vs. 3.01 are performed for the main confirmations of Fatty acids C18-unsat, dimers (C36). The BCF values are in a range of 0.89-0.94 (Log BCF:-0.027 - -0.048) for the Arnot-Gobas method on upper trophic and 3.162 (Log BCF: 0.5) for the regression based method. Based on the BCF estimates it is concluded that the Fatty acids C18-unsat. dimers, (C36) display no significant bioaccumulation potential.

 

Fatty acids C18-unsat, dimers (C36)

EPISuite v4.1/BCFBAFv3.01:BCF estimations using BCFBAF vs. 3.01 are performed for the main confirmations of Fatty acids C18-unsat, dimers (C36). A Fatty acids C18-unsat, dimers (C36) molecule consits of 2 molecules Fatty acid, C18-unst. dimer (C18). The BCF values are in a range of 0.89-0.94 (Log BCF:-0.027 - -0.048) for the Arnot-Gobas method on upper trophic and 3.162 (Log BCF: 0.5) for the regression based method. Based on the BCF estimates it is concluded that the Fatty acids C18-unsat. dimers, (C36) display no significant bioaccumulation potential.

CATALOGIC v.5.11.9:BCF calculations using the CATALOGIC v.5.11.9 BCF base-line model for four conformations of Fatty acids C18-unsat, dimers (C36) are performed. The BCF model calculates the BCF implicating the estimated log Kow value of 13.1-14.7. Furthermore, the influence of mitigating factors like ionization of the molecule, water solubility, size and metabolism are also considered by the model. Besides metabolism also the relatively low water solubility and the molecular size reduce the log BCF as estimated by the model. Both parameters are discussed within the literature whether certain threshold values are suitable as cut-off criteria for indication of limited bioaccumulation. 

 

Regarding molecular size, the PBT working group on hazardous substances discussed a maximum diameter of > 17.4 Å (Comber et al., 2006). The average diameter of the isomers are determined to be 24.6 - 28.9 Å (DiamMax-Average), depending on its conformation. When used as single mitigating factors (no combination with other factors), metabolism and size reduce the overall bioaccumulation. All in all, based on the predicted BCF of 0.873, a significant bioaccumulation is not expected in animal tissues. The structure of the main components of the test item is covered by 100 % by the mechanistic applicability domain.

 

Conclusion:

For four conformation isomere of Fatty acids C18-unsat, dimers, (C36) estimations were performed using 3 different QSAR models, Catalogic vs. 5.11.9 (base-line model 2.05) and BCFBAF vs. 3.01 using the “regression-base model” as well the “Arnot-Gobas model for upper trophic” taking into account metabolism. Based on the estimation results it is concluded that Fatty acids C18-unsat, dimers, (C36) do not bioaccumulate in organism.

 

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

The substance Fatty 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). Once the substance has entered the aquatic environment, it is expected that the substance dissociates into its components coco alkylamine and Fatty acids C18-unsat, dimers, (C36). For both components individual simulations have been performed with regard to bioaccumulation. Whereas for Fatty acids C18-unsat, dimers, (C36) there is no indication to bioaccumulate, there is a low to moderate potential for bioaccumulation for Coco alkylamine.

 

Based on the results for the individual components it is concluded that for Fatty acid C18-unsat, dimer compd. with coco alkylamine in the aquatic environment there is only a limited potential for bioaccumulation.