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The following remarks on the toxicokinetics of Castor Oil, reaction product with Soybean Oil are based on physico-chemical properties of the compound and on toxicological data. Experimental toxicokinetic studies were not performed.

The substance is a light yellow liquid with a very low vapour pressure under normal ambient conditions (1.6 x 10-5 hPa at 25 °C), therefore inhalation exposure to the vapour is expected to be negligible.

The physico-chemical characteristics of the substance (limited water solubility of 5.8 mg/L at 20°C, log Pow of 13.3 - 27.5 at 25 °C and a molecular mass of 1322 g/mol) suggest a low intestinal absorption after oral intake. This assumption is confirmed by the data on acute oral toxicity in rats (LD50 > 5000 mg/kg bw). In this study a dose of 2000 mg/kg bw was tolerated without mortalities, clinical signs, effects on body weight development or gross pathological findings (Gillissen, 2010a).

Because of the high lipophilicity of the substance accumulation of the unchanged compound in fatty tissues might be possible depending on both the absorption in the GI tract as well as the efficiency of metabolic and excretory processes.

Due to the limited water solubility, a log Pow of > 13.3 at 25 °C and a molecular mass of 1322 g/mol no appreciable dermal or mucosal absorption is anticipated. This is confirmed by the studies on acute dermal toxicity (rat, LD50 > 2000 mg/kg bw; Gillissen, 2010b) and on skin sensitization (LLNA; Vohr, 2011) in which no signs of systemic toxicity were observed. As the skin sensitisation study revealed a moderate skin sensitising potential after dermal contact of the substance formulated in methyl ethyl ketone, at least for a solution of the substance in methyl ethyl ketone some dermal absorption has to be assumed.

Based on the results of three in vitro genotoxicity tests (negative with and without metabolic activation in an Ames test (Nern, 2011), in a HPRT test (Hall, 2011) as well as in a mammalian cell micronucleus test (Sutter and Jung, 2011) it is concluded that DNA-reactive metabolites of the substance will most probably not be generated in mammals in the course of hepatic biotransformation.