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Environmental fate & pathways

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There was early on evidence that Tert-butyl-4-methoxy-4'-dibenzoylmethane (BMDBM) would not be readily biodegradable under aerobic conditions. Therefore, an anaerobic biodegradation study was conducted, using digested sludge from a municipal wastewater treatment facility. The test result was also negative. The following study on inherent biodegradability revealed that the test item is not biodegradable.

Ultimate degradation in surface water (OECD 309)

The half-life, DT50, of the parent compound in natural water was determined to be 11.9 days at high dose (0.015 mg/L) and 11.2 days at low dose (0.005 mg/L). Under sterile conditions the parent compound degraded slower than in a non-sterile conditions. The half-life was 60.2 days at a concentration of 0.015 mg/L. The parent compound degraded to two major metabolites, depending on the placement of the radiolabel and a common metabolite for both labels.

Biodegradation in sediment (OECD 308)

The half-life, DT50, of the parent compound in freshwater sediment was determined to be 124 days at 12 °C in a river water/sediment system. The half-life in the water phase was 3.5 days at 12 °C and from the entire river water/sediment system the DT50 was determined to be 83 days at 12 °C.

Using a pond water/sediment system, the DT50 for the parent compound in the sediment phase was 152 days at 12 °C, for the pond water phase 2.4 days at 12 °C and for the entire pond water/sediment system, the DT50 was 113 days at 12 °C.

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