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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

In the combined 28-day repeated dose toxicity study with the reproduction/ developmental toxicity screening test, the reported NOAEL was greater than 1000 mg/kg bw. No treatment-related changes were observed in any of the test animals (Charles River, 2016).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

In the combined 28-day repeated dose toxicity study with the reproduction/ developmental toxicity screening test, the reported NOAEL was greater than 1000 mg/kg bw. No treatment-related changes were observed in any of the test animals (Charles River, 2016).

The test item, 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane, was formulated in dried and deacidified corn oil and administered orally (gavage) to 10 male and 10 female rats per group. An extra 5 animals per sex in the control and high dose group were included and allowed 14 days of recovery. All the animals were treated daily, for at least 28 days. Main group males and recovery males were exposed to the test substance for 29 days. Main females were treated for 41 to 47 days. Recovery females were exposed for 43 days. The selected doses were 100, 300 and 1000 mg/kg bw/day, based on toxicity results from a 14-day dose range-finding study.

The following observations and examinations were evaluated: mortality / viability, clinical signs (daily), functional observations and locomotor activity (end of treatment), body weight and food consumption (at least at weekly intervals), clinical pathology (end of treatment), macroscopy at termination, organ weights and histopathology on a selection of tissues. In addition, the following reproduction/developmental parameters were determined: mating, fertility and conception indices, precoital time, number of corpora lutea and implantation sites, gestation index and duration, parturition, maternal care, sex ratio and early postnatal pup development (mortality, clinical signs, body weights, sex and macroscopy). Formulations were analysed once during the study to assess accuracy and homogeneity.

Another 28-day repeated dose oral toxicity study was available, which reported no adverse effects observed at the highest dose tested (CVH, 1995).

Justification for classification or non-classification

Based on the available data for 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane, no classification is required for repeated dose toxicity according to Regulation (EC) No. 1272/2008.