Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

(Chloromethyl)diethoxymethylsilane was examined in the fiveSalmonella typhimurium strains TA98, TA100, TA102, TA1535 and TA1537 in two independent experiments, each carried out without and with metabolic activation (a microsomal preparation derived from Aroclor 1254-induced rat liver). The first experiment was carried out as a plate incorporation test and the second as a preincubation test.

(Chloromethyl)diethoxymethylsilane was completely dissolved in dimethyl sulfoxide (DMSO). The vehicle DMSO was employed as the negative control.

The test item was examined in two preliminary cytotoxicity tests (plate incorporation test without and with metabolic activation) in theSalmonella typhimurium test strain TA100. Ten concentrations ranging from 0.316 to 5000μg/plate were tested.

Pronounced cytotoxicity (scarce background lawn and reduction of the number of revertants by more than 50%) was noted at concentrations of 3160μg/plate onwards in the test without metabolic activation.

Hence, 3160μg (Chloromethyl)diethoxymethylsilane/plate were chosen as top concentration for the main study in the experiments without metabolic activation and 5000μg/plate in the experiments with metabolic activation.

Six concentrations ranging from 10 to 3160μg (Chloromethyl)diethoxymethyl-silane/plate were tested in the plate incorporation and the preincubation test in the absence of metabolic activation and from 31.6 to 5000μg (Chloromethyl)-diethoxymethylsilane/plate in the plate incorporation and the preincubation test in the presence of metabolic activation.

Cytotoxicity (scarce background lawn and/or reduction of the number of revertants by more than 50%) was noted at the top concentration of 3160μg (Chloromethyl)-diethoxymethylsilane/plate in the plate incorporation test and in the preincubation test, each carried out without metabolic activation, in all test strains and, in addition, in the preincubation test with metabolic activation at the top concentration of 5000μg/plate in test strain TA1535.

No increase in revertant colony numbers as compared with control counts was observed for (Chloromethyl)diethoxymethylsilane, tested up to the cytotoxic concentration of 3160 (without activation) or the top concentration of 5000μg/plate (with activation), in any of the 5 test strains in two independent experiments without and with metabolic activation, respectively (plate incorporation test and preincubation test).

The positive control items showed a significant increase in the number of revertant colonies of the respective test strain and confirmed the validity of the conditions and the sensitivity of the test system.

In conclusion, under the present test conditions, (Chloromethyl)diethoxymethylsilane tested up to the cytotoxic concentration of 3160 µg/plate (without activation) or the top concentration of 5000 µg/plate (with activation) caused no mutagenic effect in the Salmonella typhimurium strains TA 98; TA1 00, TA 1535, TA 1537 and TA 102, neither in the plate incorporation nor in the preincubation test, each carried out without and with metabolic activation.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Additional information

Justification for classification or non-classification

Data are insufficient for classification or non-classification.