Reaction Mass of (1R)-1-[(1S)-3,3-dimethylcyclohexyl]ethyl formate and (1R,2S)-2,6,6-trimethylcycloheptyl formate

Biodegradation in water: screening tests

Description of key information

The substance cannot be classified as readily biodegradable as it shows 0% degradation after 28 days in an OECD TG 301D test. The biodegradation behaviour of the substance was investigated in a study according to OECD TG 301D (closed bottle test) and conducted in compliance with GLP (AkzoNobel, 2012). In this study secondary activated sludge from a STP treating predominantly domestic wastewater was exposed to 2 mg/L the substance for 28 days. The test was prolonged up to 120 days because the pass level was not reached at Day 28. Prolongation of the test did not occur under GLP conditions. The substance did not cause a reduction in the endogenous respiration nor inhibited the microorganisms degrading acetate and toxicity to micro-organisms was not a result of the substance being not readily biodegradable. The substance was biodegraded by 8% at day 28 in the standard Closed Bottle screening test. In the prolonged test, the substance was biodegraded to a maximum of 48% after 120 days. The substance should therefore not be classified as readily biodegradable. The lack of biodegradation in the Closed Bottle test does not mean that the substance is recalcitrant in nature because the stringency of the test procedures could account for the recalcitrance in the Closed Bottle test.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

In an earlier biodegradation test, according to OECD TG 301C (Modified MITI test) 14% biodegradation was found after 28-days, supporting the value for the risk assessment that the substance is not readily biodegradable. In this test the concentration of the substance was 100 mg/L, exceeding the water solubility with a factor of 10. The test was repeated because a higher biodegradation value was expected.