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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

An EC50 of 6670 mg/L for the toxicity to microorganisms of the hydrolysis product (hydroxytrimethylsilane, CAS 1066-40-6) of chlorotrimethylsilane (CAS 75-77-4) was used as the read-across substance.   This result was determined in a reliable study conducted according to an appropriate test protocol (OECD 209), and in compliance with GLP.

Key value for chemical safety assessment

EC50 for microorganisms:
6 670 mg/L

Additional information

An EC50 of 6670 mg/L for the toxicity to microorganisms of the read-across substance hydroxytrimethylsilane (CAS 1066 -40 -6) were determined in a reliable study conducted according to an appropriate test protocol (OECD 209), and in compliance with GLP.  Microorganism toxicity studies were also available for dichloro(dimethyl)silane (EC50 = 160 mg/L / NOEC = 32) and trichlorovinylsilane (EC50 > 100 mg/L).  However, the hydrolysis half-life of chlorosilanes indicate that, under conditions relevant to ecotoxicity assessment, they will rapidly hydrolyze to siilanol. The other hydrolysis product is hydrogen chloride; the properties of this substance are well characterized. Its effects on aquatic organisms are limited to those that result from changes to pH in unbuffered media and are discussed in the CSR. Therefore, the value for the hydrolysis product of chlorotrimethylsilane (hydroxytrimethylsilane) was used for read-across to MS-Silane.

 

The following information is taken into account for effects on aquatic micro-organisms for the derivation of PNEC:

Value used for CSA: EC50: 6670 mg/L

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