2,2,6,6-Tetramethylpiperidin-4-yl dodecanoate

Short-term toxicity to aquatic invertebrates

Description of key information

In a semi-static acute toxicity test, young Daphnia magna (< 24 h old) were exposed to the test item for 48 hours according to OECD 202. The effect concentrations are based on the measured concentration (geometric mean) as following: NOEC = 0.15 mg/L, LOEC = 0.315 mg/L and EC50 = 0.383 mg/L. 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.383 mg/L

Additional information

The acute toxicity of the test substance to the freshwater crustacean Daphnia magna was assessed in a key study according OECD Guideline for Testing of Chemicals No. 202, Daphnia sp., Acute Immobilisation Test. The toxicity evaluation of the test item for Daphnia magna (< 24 hour old) was performed in the semi-static test in a closed design with 48 h of exposure. The test was performed using Elendt M7 medium for culturing and as diluent for preparing the test concentrations.The nominal test concentrations were 0.06, 0.12, 0.24, 0.48, 0.95 and 1.9 mg/L (geometric mean: 0.035, 0.077, 0.150, 0.315, 0.541, 1.035 mg/L). The effect concentrations (mg/L) after 48 h based on the measured concentration was EC50 = 0.383 mg/L, LOEC = 0.315 mg/L, and NOEC = 0.15 mg/L.  

In addition to that a supporting study was performed to evaluate the acute toxicity of the test substance with a low level of humid acid. This study investigated the effect of the test substance on the immobilisation of Daphnia magna according also to OECD Guideline for Testing of Chemicals No. 202, Daphnia sp., Acute Immobilisation Test (2004). Juvenile daphnids (< 24 hour old) were exposed to various concentrations of the test substance and compared to a control. The test concentrations were 0 (control), 0+ (control + humid acid as 1 mg TOC/L), 0.06, 0.12, 0.24, 0.48, 0.95, 1.90 mg/L as nominal concentrations based on test substance mass without a correction for purity. Analytical monitoring was not conducted. Immobilisation of daphnids was determined after 24 and 48 hours of exposure under semi-static conditions. The M4 test medium used in this study was amended with a low level of humic acid equivalent to 1 mg/L total organic carbon in order to better approximate a natural surface water and still represent a worst case scenario exposure. A range of 10 – 20 mg/L of humic acid has been suggested as a suitable level for aquatic testing and being representative of surface water levels.The water parameters oxygen content and pH were recorded at start and end of the exposure period. The water parameters were within the ranges required by the OECD.  The NOEC was determined to be 0.95 mg/L and the EC50 was determined to be higher than 1.90 mg/L