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

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-03-14 to 2016-03-29

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 402 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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-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:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Germany
- Age at study initiation: males: 9-10 weeks old; females: 12-13 weeks old
- Weight at study initiation: males: 244 - 250 g; females: 208 - 216 g
- Housing: The animals were kept individually in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding.
- Diet: Altromin 1324 maintenance diet for rats and mice, ad libitum
- Water: tap water, sulphur acidified to a pH value of approximately 2.8, 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

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: the dorsal area of the trunk
- % coverage: 10 %
- Type of wrap if used: The dressing consisted of a gauze-dressing and non-irritating tape and was fixed with an additional dressing in a suitable manner.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): At the end of the exposure period the residual test item was removed using aqua ad injectionem
- Time after start of exposure: 24 hours

TEST MATERIAL
- Constant volume or concentration used: yes

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were weighed on days 1, 8 and 15. Clinical observations were made at 30 min, then at 4 hours post-application. Thereafter, the animals were examined daily for the rest of the 14-day study period.
- Necropsy of survivors performed: yes
- Other examinations performed: Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined. Attention was directed to observations of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma. All animals were subjected to gross necropsy. Cranial, thoracic and abdominal cavities were examined macroscopically. In absence of gross pathological changes no tissues were preserved for a possible histopathological evaluation.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the 14-day observation period.

Clinical signs:

other: No signs of systemic toxicity were noted in any of the test animals.

Gross pathology:

Focus, dark liver was noted in one female at necropsy, however these incidental findings are not considered to be test-item related. With the exception of acute injection of blood vessels in the abdominal region, which is due to the euthanasia injection, no specific gross pathological changes were recorded for any other animal.

Other findings:

No signs of dermal irritation were observed in any of the test animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

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