Dimethyl itaconate

Short-term toxicity to aquatic invertebrates

Description of key information

Considered “slightly toxic” based on pre-test data 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

27 mg/L

Additional information

Experimental data on short-term effects to aquatic invertebrates are available from a pre-test to a long-term toxicity test on daphnid reproduction. Testing for short-term effects, required in Annex VII, column 1, section 9.1.1., has been waived in accordance with the column 1 suggestion to consider long-term testing instead.

The acute primary consumer ecotoxicity of the submission item Dimethyl itaconate (CAS 617-52-7) to aquatic invertebrates (Daphnia magna) was measured in a non-GLP pre-test to a “Daphnia magna Reproduction Test” (Harris 2014, Harlan Laboratories Report no. 41301814). The applied protocol was comparable to OECD TG 202 (2004) standards, but a test concentration spacing factor of 10 was used. The experiment is sufficiently documented and can be considered relevant, but not fully adequate for the endpoint. Therefore it is deemed conclusive and was rated „reliable with restrictions“, i.e. “Klimisch 2”.

One replicate of ten first instar larvae was for 48 h under static conditions exposed to nominal test item concentrations of 0.10, 1.0, 10 and 100 mg/L. The analytical determination of the 10 and 100 mg/L nominal concentrations revealed recoveries of 67 and 86 % of nominal, respectively. Therefore the effects had to be assigned to measured concentrations.

Equally at 24 and 48 h, all test organisms survived at nominal 10 mg/L while all individuals were immobilized at nominal 100 mg/L. These concentrations correspond to geometric mean measured concentrations of 7.9 and 94.1 mg/L, respectively. Accordingly the LC0 and LC100 were assigned to these concentrations. The approximated LC50 was calculated as the geometric mean of LC0 and LC100 resulting in ca. 27 mg/L.

According to a scheme, available from U.S. EPA (1994, p 10) the observed LC50 falls into the > 10 to 100 mg/L category of substances considered “slightly toxic” to aquatic invertebrates represented by daphnids. On the basis of this study alone no classification is indicated according to CLP (5th ATP of Regulation (EC) No 1272/2008 of the European Parliament and of the Council) as implementation of UN-GHS in the EU. It is known that the test material is subject to ready biodegradation by micro-organisms under non-sterile conditions. Eisner (2011, Harlan Laboratories study report no. D32045), found 17 % degradation until day 3 in a OECD TG 301 A study. Under the non-sterile conditions of this study the observed depletion of the test item can be attributed to bacterial biodegradation know to reach relevant levels in the time frame of the incubation periods (see section on biodegradation in water: screening tests).

• Klimisch HJ, Andreae M, Tillmann U (1997). A Systematic Approach for Evaluating the Quality of Experimental Toxicological and Ecotoxicological Data. DOI 10.1006/rtph.1996.1076 PMID 9056496 Regul Toxicol Pharmacol 25:1-5.
• U.S. EPA United States Environmental Protection Agency (1994). Pesticide Reregistration Rejection Rate Analysis, Ecological Effects. Self-published EPA, Office of Prevention, Pesticides and Toxic Substances (OPPTS), Washington, DC, U.S.A., document number 738-R-94-035. 188 p.