Registration Dossier

Administrative data

Description of key information

The key acute oral toxicity study, conducted according to OECD TG 423, and in compliance with GLP, reports an LD50 value of >2000 mg/kg bw for 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane (LPT, 2002).

The key acute dermal toxicity study, conducted according to OECD TG 402, and in compliance with GLP, reports an LD50 value of >2000 mg/kg bw for 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane (DCC, 2000).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
LD50
2 000 mg/kg bw

Additional information

The key acute oral toxicity study, conducted according to OECD TG 423, and in compliance with GLP, reports an LD50 value of >2000 mg/kg bw for 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane (LPT, 2002). The key study was selected, because it was the most recent study available.

Following oral administration of 1.9 mL of 2000 mg/kg bw/day of test material to 3 male and 3 female rats, no mortality or signs of systemic toxicity were observed during the 14-day observation period. No changes in body weight gain were noted. At the end of the observation period, necropsy was performed and there was no evidence for macroscopic abnormalities in any of the test animals.

There was a supporting acute oral study available, conducted according to OECD TG 401, and in compliance with GLP, which also reports an LD50 value of >2000 mg/kg bw in rats for 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane (DCC, 2001).

Following oral administration of 2000 mg/kg bw of test material to 5 male and 5 female rats, no mortality or signs of systemic toxicity were observed during the 14 -day study period. No changes in body weight gain were noted. No macroscopic abnormalities were noted at necropsy.

The key acute dermal toxicity study, conducted according to OECD TG 402, and in compliance with GLP, reports an LD50 value of >2000 mg/kg bw for 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane (DCC, 2000).

Following 24-hour dermal application of 1.87 ml/kg of 2000 mg/kg bw of test substance to the skin of 5 male and 5 female rabbits, no mortality or signs of systemic toxicity were observed during the 14 -day study period. Body weight loss was noted in two females on day 8, and in another female on days 8 and 15. The expected body weight gain was observed in the rest of the test animals. Gaseous distension in the large intestine was noted in one animal at necropsy, while no macroscopic abnormalities were observed in the rest of the animals.


Justification for classification or non-classification

Based on the available data for 1,3,3,5-tetramethyl-1,1,5,5-tetraphenyltrisiloxane, no classification for acute toxicity is required according to Regulation (EC) No 1272/2008.