Decyl laurate

Endpoint summary

Additional information

There is only limited data available for the aquatic toxicity of decyl laurate (CAS 36528-28-6). Therefore, the aquatic toxicity of the target substance was assessed by means of a read-across approach, through which additional data for two structurally and chemically closely related source substances was compiled in order to fulfill the standard information requirements laid down in Annex VIII of REACh Regulation (EC) No 1907/2006. Read-across was performed in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5.

According to Article 13 (1) of this regulation, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” For aquatic toxicity in particular, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across). In regard to the general rules for grouping of substances and the read-across approach, the regulation specifies (Annex XI, Item 1.5) that substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. The selected source substances tetradecyl myristate (CAS 3234-85-3) and fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0) are characterized by similar fatty acid and alcohol components as the target substance. Based on the high degree of structural similarity as well as similar physico-chemical properties of the target and selected source substances, the target substance is expected to have a similar ecotoxicological profile as the selected source substances. A detailed analogue approach justification is provided in IUCLID section 13 of the technical dossier.

By means of the read-across approach, GLP guideline studies are available for the short-term aquatic toxicity of the target substance to two trophic levels (fish and aquatic algae) and the long-term aquatic toxicity to one trophic level (aquatic algae). Due to the extremely low water solubility of the target substance (< 0.528 µg/L, OECD 105), long-term testing on aquatic invertebrates was considered necessary to fully assess the potential aquatic hazard. Therefore, a testing proposal according to OECD 211 is included to cover the third trophic level represented by aquatic invertebrates. In addition, one experimental study is available for the toxicity to microorganisms.

 

For the short-term toxicity to fish, two experimental studies are available for the source substances

tetradecyl myristate (CAS 3234-85-3) and fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0), respectively. Both tests were performed according to according OECD guideline 203 and GLP. After 96 h of exposure of the model organism Danio rerio to water accommodated fractions of the respective test items, no mortality was observed and it was concluded that neither test item causes short-term toxic effects to fish up to the limit of water solubility.

For the toxicity to aquatic algae, an experimental study with the target substance itself is available, which was conducted according toOECD guideline 201 and GLP. After 72 h, inhibition of growth rate and yield was less than 50% and no significant inhibition was observed. Therefore, the ErC50 (72 h) and EyC50 (72 h) is considered to be greater than the highest concentration tested and is reported as > 1.3 mg/L. The reported NOEC is 1.3 mg/L for growth rate and yield inhibition and the ErC10 (72 h) and EyC10 (72 h) are both > 1.3 mg/L, respectively.

For the toxicityto activated sludge microorganisms, one experimental study with the source substancefatty acids, C8-10, C12-18-alky esters (CAS 95912-86-0) is available, which was performedaccording to OECD guideline 209 and GLP.After 3 h incubation, no effects were observed based on the respiration rate resulting in an EC10 (3 h) of > 1000 mg/L.

In summary, the compiled data for short-term toxicity (fish and aquatic algae) and long-term toxicity (aquatic algae) neither indicate any short-term nor long-term toxicity to aquatic organisms up to the limit of water solubility. Furthermore, no inhibitory effects towards microorganisms of activated sludge were recorded.

 

Due to the ready biodegradability (67% in 28 d, OECD 301 C) and the high adsorption potential (9.7, Meylan/Kowwin v1.1.4 calculation) of the target substance, the substance is expected to be eliminated from sewage treatment plants to a high extent. Release to the aquatic environment and subsequent exposure of sediment is therefore very unlikely. Furthermore, the substance is a long-chain aliphatic ester. Therefore, in the unexpected event where absorption of the substance by aquatic organisms should occur, it is expected to be rapidly metabolized via enzymatic hydrolysis into its corresponding fatty acids and fatty alcohols, which are known from literature to metabolize well in aquatic organisms. Against this background, the overall potential for chronic exposure and for bioaccumulation in aquatic organisms is judged to be very low.

Therefore, it can be concluded that the target substance decyl laurate (CAS 36528-28-6) presumably does not cause short-term or long-term toxicity to aquatic organisms up to the limit of water solubility (< 0.528 µg/L, OECD 105) and is not expected to affect the degradation process in commercial sewage treatment plants.