Dimethyl itaconate

Biodegradation in water: screening tests

Description of key information

Readily and rapidly biodegradable (90 % degradation at day 7, thus 10-day window met); concentration of 55 mg/L not inhibitory to activated sludge

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The Ready Biodegradability of the submission item Dimethyl itaconate (CAS 617-52-7) was measured in a GLP-compliant study (Eisner 2011, Harlan Laboratories Report no. D32045) using the “Dissolved Organic Carbon (DOC) Die-Away Test” compliant with EU Method C.4-A (Commission Regulation (EC) No. 440/2008), OECD TG 301A (1992) and US EPA OCSPP (former OPPTS) 835.3110 paragraph l (1998) protocols. The validity criteria were met and the experiment can be considered relevant and adequate for the endpoint. Therefore it is deemed conclusive and was rated „reliable without restrictions“, i.e. “Klimisch 1” according to the scale of Klimisch et al. (1997).

The reference item sodium benzoate was completely (>90 %) biodegraded within seven days of exposure, thus confirming suitability of the activated sludge. In the test flasks, containing the test item and activated sludge (inoculum), the mean concentrations of dissolved organic carbon (DOC) rapidly decreased by 17 % of the initial value at the first sampling point (day 3) and reached 90 % at day 7, 96 % at day 10, 91 % at day 14 and eventually 95 % at day 21. In accordance with the testing guidelines the test was ended after 21 days since the biodegradation curves of the test and the reference item had reached a plateau over at least three determinations. The pass level for ready biodegradability (i.e. 70 % removal of DOC in a 10-day window within a 28-day period) was clearly reached. Therefore, the test item was found to be readily biodegradable under the test conditions. In the toxicity control, containing the test item, the reference item sodium benzoate and activated sludge (inoculum), the initial DOC decreased by 96 % within 14 days of exposure. Thus, according to the test guidelines the test item was not inhibitory to activated sludge at the tested concentration of 55 mg/L because degradation was >35 % within 14 days.

In conclusion the submission item was readily and rapidly biodegradable with 90 % degradation at day 7. Thus the 10-day window was met. The concentration of 55 mg submission item/L was not inhibitory to activated sludge metabolism.

• 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.