1,1,5,5,5-hexamethyl-3,3-bis[(trimethylsilyl)oxy]trisiloxane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 30 2001 - July 23 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Study was not conducted in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Guidance on Safety Assessment of New Cosmetics (Japan Cosmetic Industry Association, technical materials No.92, 1991

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy]trisiloxane

EC Number:

241-867-7

EC Name:

1,1,1,3,5,5,5-heptamethyl-3-[(trimethylsilyl)oxy]trisiloxane

Cas Number:

17928-28-8

Molecular formula:

C10H30O3Si4

IUPAC Name:

trimethyl-[methyl-bis(trimethylsilyloxy)silyl]oxysilane

Test material form:

other: liquid

Test animals

Species:

rat

Strain:

other: Crj:CD(SD)IGS

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Atsugi Breeding Center, Charles River Japan Inc.
- Age at study initiation:6 weeks
- Weight at study initiation: male 193-212 g, female 131-151 g
- Fasting period before study: ca. 18 hours
- Housing: Individually housed, in stainless steel bracket cages for rats
- Diet : ad libitum
- Water: ad libitum
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 50 +/- 20
- Air changes (per hr): minimum 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 100 or 200 mg/mL


MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg


CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: According to the Guidance on Safety Assessment of New Cosmetics, 2000 mg/kg was set for the high dose group, 1000 mg/kg for the low dose group, and olive oil for the control group.

Doses:

vehicle at 0 mg/kg, 1000 and 2000 mg/kg

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for clinical signs and mortality at 15, 30 minutes, 1, 3 and 6 hours after treatment on the day of treatment and thereafter once daily. Animals were weighed on the day of treatment and on days 2, 3, 4, 8, 11 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other: The body surface and the intracranial, intrathoracic and intra-abdominal organs were macroscopically examined. Histopathological examination was not performed because necropsy did not reveal any abnormal changes.

Statistics:

The body weight measurements obtained in the study were averaged and standard deviation was calculated for each group, which were analysed for homogeneity of variance by F-test. Since the results showed homogenous variance, Student t-test was performed. There was no statistical significance noted.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths occurred through the observation period in either males or females in all the groups including the control group in response to test article administration.

Clinical signs:

No clinical signs caused by the test substance were observed. Watery diarrhoea was observed in males and females in all groups, which ceased by day 2 of treatment, after which no special changes were observed.

Body weight:

During the observation period, there was no statistical difference in body weight measurements between the groups. The body weight of each group increased favourably.

Gross pathology:

There were no remarkable findings at necropsy in any group of animals.

Other findings:

None reported.

Applicant's summary and conclusion

Interpretation of results:

Category 5 based on GHS criteria

Remarks:

Not classified according to Regulation (EC) No 1272/2008

Conclusions:

An LD50 value of >2000 mg/kg bw in rats of both sexes is reported in a study equivalent to the now-deleted OECD 401 Guideline, which was not GLP compliant.