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Environmental fate & pathways

Endpoint summary

Administrative data

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Additional information

The registered compound shows a fast hydrolysis under environmental conditions. The half-life of the registered substance is << 2 min at pH 7 and room temperature (measured). Therefore, hydrolysis is a relevant pathway for the degradation of the parent compound in the environment. The resulting hydrolysis products are hydrochloric acid and hexadecylsilanetriol. Photolysis cannot be expected to contribute to the overall degradation of trichloro(hexadecyl)silane (CAS No. 5894-60-0) in air. Trichloro(hexadecyl)silane and its silanol hydrolysis product do not contain chromophores that would absorb visible or UV radiation, so direct photolysis is not likely to be significant. Indirect photolysis resulting from gas-phase reaction with photochemically-produced hydroxyl radicals may occur. The calculated photodegradation half-life based on the reaction with hydroxyl radicals is 3.5 days for the registered compound and 0.5 days for its silanol hydrolysis product. Therefore, photodegradation could contribute to the degradation of the silanol hydrolysis product in the environment. Because the estimated vapour pressure of the silanol hydrolysis product is low (< 1.0E-05 Pa at 25 °C (QSAR)), however, photodegradation in air is not a relevant pathway for degradation of the silanol hydrolysis product hexadecylsilanetriol.