Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

There are no chronic test results available. However, acute toxicity tests for the 3 trophic levels are available.

For the acute toxicity towards fish there is one study available according to the OECD guideline 203 under semi-static conditions. During 96 hours 7 test organisms were exposed to 0.529 - 1.07 - 2.27 - 4.55 - 9.58 mg/L (geometric mean measured concentrations). The LC50 after 96 hours was 3.21 mg test item/L.

In an OECD 202 study under static conditions over a duration of 48 hours the acute toxicity of the test item to Daphnia magna was evaluated. The test concentrations were 88.4, 46.5, 21.9, 10.2 and 4.42 mg/L (measured concentrations).

After 48 hours the EC50 was 12.1 mg/L.

For the toxicity to algae a publication is available in which the effects of the test item on the growth and physiological characteristics of Chlorella pyrenoidosa were assessed. The test organisms were exposed to 2.0, 4.0, 8.0 and 10.0 mg/L (nominal concentrations). Although the test concentrations were not analytically verified, the exposure concentrations were stable during the test as both effects based on inhibition of the growth rate and the level of chlorophyll tend to increase with increasing concentration levels and exposure time. The EC50 at 96 h was determined to be 5.45 mg/L.

Additionally, read-across was done from the source substane methyl cinnamate. On this source substance a study with Pseudokirchneriella subcapitata was performed in accordance with OECD guideline 201 and EU guideline C.3. In this study, significant inhibitory effect on the growth rate and yield of the algae after 48 and 72h was observed, yielding a 72h ErC50 of 7.6 mg/L and a 72h ErC10 of 4.0 mg/L. Based on these results, and on the structural, chemical and toxicological similarities between the source and target substance, the 72h ErC50 for algae in the target substance ethyl cinnamate is calculated to be 8.26 mg/L and the ErC10 is 5.00 mg/L, taking into account the difference in molecular weight between source and target substance.

In conclusion, based on the available information, it can be assumed that fish are the most sensitive species and therefore an LC50 of 3.21 mg/L is used in the hazard assessment and derivation of aquatic PNECs.

Additional information