Registration Dossier

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

The aquatic toxicity of fatty acids has been evaluated in studies on fish, daphnids and algae as well as microorganisms. Most of the studies were conducted with fatty acid homologues. Most tests are available for the soluble octanoic acid C8 (CAS 124 -07 -2), the azelaic acid C9 (CAS 123 -99 -9), the decanoic acid C10 (CAS 334 -48 -5) and the lauric acid C12 (CAS 143 -07 -7). In addition some studies were conducted with the insoluble pure homologues myristic acid C14 (CAS 544 -63 -8), palmic acid C16 (CAS 57 -10 -3) and stearic acid C18 (CAS 57 -11 -4) and certain mixtures.

In case of the mixture C14 -22 fatty acids (CAS 68424 -37 -3) read across is performed to the homologues C14, C16 and C18, which are the main components of the substance (content of C14: < 15%, content of C16: < 30% and content of C18: 5 -65%). In addition C20 and C22 are contained in the fatty acid mixture C14 - 22 with a content of 5 - 45% (C20) and 30 - 60 % (C22). Both homologues are insoluble in water and no aquatic tests are available. Aquatic toxicity of these substance is thus not expected.

Generally it could be stated that toxicity of fatty acids to aquatic organisms increases with increasing chain length up to the water solubility limit at a chain length of C12. For longer chains no effects at saturation are observed.

As the mixture C14 -22 fatty acids contains only poorly soluble homologues, for which absence of acute effects on aquatic organisms could be proved in several tests, no risk for fish, daphnids and algae, as well as microorganisms are expected. Concerning chronic toxicity no chronic effects in the range of water solubility were reported in the available tests for myristic acid (C14) and palmic acid (C16). Nevertheless in the study conducted with myristic acid (C14) significant chronic effects at concentrations slightly above the water solubility of the substance given in the report were described. By taking into account the experimentally determined solubility limits cited under the phys. -chem. chapter of the certain fatty acid pure homologues, chronic effects caused by myristic acid (C14) are unlikely.

Categories Display