Registration Dossier

Classification & Labelling & PBT assessment

PBT assessment

Administrative data

PBT assessment: overall result

PBT status:
the substance is not PBT / vPvB
Justification:

Tetramethylsilane is not readily biodegradable and is not expected to hydrolyse, and therefore meets the criteria for persistence (P) (see Section 4.1.2.1.2). Although volatility is not usually considered in assessing the persistence, the boiling point of 27°C is so close to ambient temperature that it is unlikely that any substance would be found in aquatic or terrestrial compartments.

No data are available for the bioaccumulation of tetramethylsilane. However it has a predicted log Kow approx. 3 and so does not meet the criteria for bioaccumulation.

The substance is not classified for long-term human health effects (none of the following R phrases apply: R45, R46, R48, R49, R60 – R63). The substance is classified for aquatic toxicity, on the basis of effect concentration values for fish. However, all L(E)C50‟s for fish, daphnia and algae are >0.1 mg/l Therefore, the substance does not meet the criteria for toxicity; it is not T.

The substance may persist in the environment and meets the P screening criteria. However, it does not meet the criteria for B or T. Therefore, the substance does not meet the criteria for PBT or vPvB.

(Cf Chemical Safety Report §8)