1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-03-01 to 2016-03-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane

EC Number:

241-881-3

EC Name:

1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane

Cas Number:

17955-88-3

Molecular formula:

C15H38O2Si3

IUPAC Name:

2,2,4,6,6-pentamethyl-4-octyl-3,5-dioxa-2,4,6-trisilaheptane

Test material form:

other: liquid

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Germany
- Age at study initiation: 9-10 weeks old
- Weight at study initiation: 160-174 g
- Fasting period before study: Prior to the administration food was withheld from the test animals for 16 to 19 hours. Food was provided again approximately 4 hours post dosing.
- Housing: The animals were kept in groups in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding
- Diet: food, ad libitum
- Water: water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3 °C
- Humidity (%): 55 +/- 10%
- Air changes (per hr): 10 x / hour
- Photoperiod (hrs dark / hrs light): 12 hours light, 12 hours dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: The starting dose was selected to be 2000 mg/kg body weight.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Step 1: 3 females
Step 2: 3 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals were weighed on days 1, 8 and 15. Clinical examinations were made at 30 min, 4 hours post-administration, then daily until the end of the study observation period.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight and macroscopic examinations at necropsy

Results and discussion

Preliminary study:

Following oral administration of 2000 mg/kg bw test substance to 3 female rats, no mortality occurred and no clinical signs of toxicity were observed in any of the animals.

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the 14-day study period.

Clinical signs:

other: No signs of clinical toxicity were observed during the 14-day study period.

Gross pathology:

No specific gross pathological changes were noted for any of the animals.

Other findings:

Acute injection of blood vessels in the abdominal region, which is due to the euthanasia injection

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute oral toxicity study, the reported LD50 value for test substance, 1,1,1,3,5,5,5-heptamethyl-3-octyltrisiloxane, was > 2000 mg/kg bw.