Potassium (Z)-N-methyl-N-(1-oxo-9-octadecenyl)aminoacetate

Short-term toxicity to aquatic invertebrates

Description of key information

EC50 (48 h) = 0.43 mg/L (measured, geometric mean, OECD 202, D. magna), read-across

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.43 mg/L

Additional information

There is no study available investigating the short-term toxicity of Potassium (Z)-N-methyl-N-(1-oxo-9-octadecenyl) aminoacetate (CAS 76622-74-7) to aquatic invertebrates. Therefore, read-across was conducted to the related source substances (Z)-N-methyl-N-(1-oxo-9-octadecenyl)glycine (CAS 110-25-8) and Sodium N-methyl-N-(1-oxo-9-octadecenyl)aminoacetate (CAS 3624-77-9) in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. Based on the high degree of similarity between the structural and physico-chemical properties of the target and source substances, the source substances are considered suitable representatives for the assessment of the short-term toxicity of the target substance to aquatic invertebrates. The read-across approach is justified in detail within the analogue justification in IUCLID section 13.

Three studies are available of which two studies investigated the acute toxicity of (Z)-N-methyl-N-(1-oxo-9-octadecenyl)glycine (CAS 110-25-8) to aquatic invertebrates.

In the first study, conducted according to the OECD guideline 202 and GLP with the source substance Z)-N-methyl-N-(1-oxo-9-octadecenyl)glycine (CAS 110-25-8), D. magna was exposed to the nominal concentrations of 0.1, 0.22, 0.46, 1.0, 2.2, 4.6, 10, 22, 46, and 100 mg/L (for 48 h under static conditions. Test item concentrations were analytically verified by HPLC at the beginning and end of the test. In treatments < 1 mg/L no test item could be analyzed after 48 h. The recovery after 48 h for treatments 1 – 100 mg/L was in the range of 44 – 128% of the nominal concentrations. Therefore, the determination of the biological results was based on the mean measured concentration for the test concentrations 1 – 100 mg/L and on the initial measured concentration for the test concentration 0.46 mg/L. After 48 h, an EC50 of 0.43 mg/L (geometric mean measured) was obtained.

In the second study conducted according to EU method C.2 with the substance (Z)-N-methyl-N-(1-oxo-9-octadecenyl)glycine (CAS 110-25-8), D. magna was exposed to 0.098, 0.195, 0.39, 0.781, 1.56, 3.12, 6.25, 12.5, 25.0, and 50.0 mg/L nominal test item concentrations for 48 h under static conditions. Tween 80 was used as vehicle at equal concentrations as the test item at every treatment level. The test item concentrations were not analytically verified. The obtained EC50 after 48 h was 0.53 mg/L (nominal).

In the third study conducted according to OECD 202 and GLP with the substance Sodium N-methyl-N-(1-oxo-9-octadecenyl)aminoacetate (CAS 3624-77-9), D. magna was exposed to 0.5, 1.0, 2.5, 5.0, 10, and 25 mg/L test item for 48 h under static conditions. The test item concentrations were not analytically verified. The reported EC50 (48 h) is 1.4 mg/L (nominal).

Based on the available results from the structurally related source substances (in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5), which are characterized by a similar ecotoxicological profile and comparable structure, an EC50 (48 h) of 0.43 mg/L (geom. mean measured) is retained as effect concentration for the acute toxicity of the target substance Potassium (Z)-N-methyl-N-(1-oxo-9-octadecenyl) aminoacetate (CAS 76622-74-7) to aquatic invertebrates.