Registration Dossier

Administrative data

Description of key information

In the key acute oral toxicity study, conducted according to OECD 401 and in compliance with GLP, the LD50 for male and female rats was >2000 mg/kg (Huls, 1998). Clinical symptoms were noticed 30 minutes to six hours after treatment. Abnormal gait, squatting position, sedation, paddling movements, piloerection, diarrhea and diuresis were observed. From day one until the end of the study (day 14) no other clinical signs were observed. No abnormalities were detected at necropsy.
In the acute inhalation study, conducted in accordance with OECD 403 and in compliance with GLP, the LC50 was determined to be >21.3 mg/l in male and female rats (Muijer, 1998). There were no mortalities or clinical signs of toxicity. Findings at necropsy consisted of abnormalities in the lungs, intestines and testes. Abnormalities of the lungs consisted of petechiae and/or hyalin spots or areas on one or more lobes in most animals. Pale discolouration of the lungs was seen in one male animal.
In the key acute dermal toxicity study, conducted according to OECD 402 and in compliance with GLP, the LD50 for male and female rats was determined to be >2000 mg/kg. (Huls, 1998). There were no clinical signs, signs of local irritation or abnormalities at necropsy.

Key value for chemical safety assessment

Additional information

The key acute oral and dermal toxicity studies (Huls, 1998a and Huls, 1998b) were the only available data for those endpoints. The studies were conducted in accordance with appropriate OECD test guidelines and in compliance with GLP, and were therefore assigned Reliability 1.

The key acute inhalation toxicity study (Muijer, 1998) was selected as the most reliable study available for this endpoint. It was conducted according to OECD 403 and in compliance with GLP, and was therefore assigned Reliability 1. An additional non-standard inhalation study is available in which the exposure duration was only 30 minutes.

Justification for classification or non-classification

Based on reliable measured data for the oral, inhalation and dermal routes, tetramethylsilane is not classified for acute toxicity according to EU Directive 67/548/EEC and Regulation 1272/2008.