[[4-[[2-(4-cyclohexylphenoxy)ethyl]ethylamino]-2-methylphenyl]methylene]malononitrile

Endpoint summary

Description of key information

Bioaccumulation in aquatic/sediments:

The observed BMF was 0.0026 of test chemical on fish Danio rerio  in 20 days. On the basis of this BMF value it is concluded that this test chemical is non bioaccumuative in nature.

Additional information

Bioaccumulation in aquatic/sediments:

For determination bioaccumulation factor an experiment was conducted with food instead of water as the exposure route (Experimental study report, 2009). Apart from that, the general provisions of OECD TG 305 – Bioconcentration: Flow-through Fish Test (June 1996) which is equivalent to the Council regulation (EG) 440/2008 EU method C.13, Bioconcentration: Flow-Through Fish Test (2008) were used to conduct the study. The “Background document to the Fish Dietary Study-Protocol” and “Fish Dietary Bioaccumulation Study - Basic Protocol” was used as guidance. This study consists of two phases the exposure phase and post exposure phase(depuration).During the uptake phase, separate groups of fish of one species are fed with a special diet of fish food mixed with at least two concentrations (100 and 1000 μg/g fish food) of the test item. As a reference compound hexachlorobenzene is also added to the fish diet at a nominal concentration of 100 μg/g. The uptake phase is run for 20 days. The concentration of the test item in control and test diets are analysed one day prior to the uptake phase, at the beginning of the uptake phase and 10 days thereafter. The test item and reference compound concentration in fish is followed by HPLC analysis and UV/VIS-detection 10 days after beginning of the uptake phase and at the end of the uptake phase. A tissue specific analysis was also carried out on dissected fish and the separated guts of the fish at the end of the uptake phase. The test dilution water was measured one day prior to the beginning of the uptake phase and on day 10 and 20 of the uptake phase for the control and both test item concentrations. After 20 days the depuration period is begun by feeding the fish with a diet free from the test item and the reference compound. During the depuration phase fish samples were taken at several times for analysis. Fish for tissue specific analysis were also taken, the guts were removed and both, dissected fish and guts were analysed separately. After a period of 28 days, the concentration of test item in fish was below the LOQ of of test chemical of 0.401 μg/g fish wet weight and that was the last data point to be included in the regression to estimate the depuration rate constant. The lipid cocntent of fish at start of exposure was 8.5 % and at end of exposure was 13.1 %. The test item was shown to be stable in spiked fish food with recoveries ranging from 97.5 to 99.8% at the test item concentration 100 μg/g and 99.2 to 105.2% at the test item concentration 1000 μg/g (3 repeat determinations during uptake phase). The recoveries for the reference compound hexachlorobenzene in spiked fish food ranged from 86.9 to 97.1% at the test item concentration 100 μg/g and from 70.3 to 106.7% at the test item concentration 1000 μg/g, respectively. The uptake efficiency (α) for HCB was 0.548 (54.8%) at a HCB concentration of 100 μg/g (and a test item concentration 1000 μg/g) indicating suitability of the test system. For the test item an uptake efficiency of 0.063 (6.3%) for the test item concentration 1000 μg/g was calculated. Because of limited uptake, at a test item concentration of 100 μg/g the concentration in fish tissue after 20 days uptake was below the LOQ and therefore no assimilation efficiency could be determined. The mean recovery of test item from spiked fish tissue was 97.5%, while the mean recovery of the reference compound hexachlorobenzene was 93.2%. Some fish were dissected and fish tissue and gut samples were analysed separately. From the data, correcting for fish growth during the test, a BMF of 0.0026 was determined for the test item concentration 1000 μg/g. After 28 days of depuration (i.e. feeding unspiked food), no test chemical could be determined any more. At a concentration of 100 μg/g the bioaccumulation was too low to allow quantification. The calculated half life of the test item from the above data was 9.706 days. The observed BMF was 0.0026 of test chemical on fish Danio rerio  in 20 days. On the basis of this BMF value it is concluded that this test chemical is non bioaccumuative in nature.