Trisiloxane, 3-ethyl-1,1,1,3,5,5,5-heptamethyl-

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 Oct 2016 - 17 Oct 2016

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:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

24 February 1987

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

469-070-1

EC Name:

-

Cas Number:

17861-60-8

Molecular formula:

C9H26O2Si3

IUPAC Name:

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

Test material form:

liquid

Remarks:

Clear colourless liquid

Test animals

Species:

rat

Strain:

Wistar

Remarks:

RccHAN (TM); WIST

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 to 12 weeks
- Weight at study initiation: at least 200g, weight variation did not exceed +/- 20% of the mean weight for each sex
- Housing: individually during 24h exposure period, in groups of 5, by sex, for the remainder of the study
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19 - 25°C
- Humidity: 30 - 70%
- Air changes (per hr): 15
- Photoperiod (dark / hrs light): 12h/12h

IN-LIFE DATES: From: 03 Oct 2016 To: 17 Oct 2016

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: back and flanks
- % coverage: approx. 10%

REMOVAL OF TEST SUBSTANCE
- Washing (if done): treated skin and surrounding hair wiped with cotton wool moistened with distilled water
- Time after start of exposure: 24h

TEST MATERIAL
- Amount applied: 2.44mL/kg bw

Duration of exposure:

24h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Duration of observation period following administration: 14 days
Frequency of observations and weighing observation after dosing: 30min, 1, 2, 3 and 4 h and subsequently daily for 14 days, body weights recorded on days 0, 7 and 14
Evaluation of skin reactions: after removal of dressing and subsequently once daily for 14 days
- Necropsy of survivors performed: yes

Statistics:

Not performed

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

no mortality observed

Clinical signs:

other: no signs of systemic toxicity observed

Gross pathology:

no abnormalities were noted at necropsy

Any other information on results incl. tables

table1: results male

male animal nr		observation time
		1-7d	8-14d
1-0	erythema	0	0
	edema	0	0
1-1	erythema	0	0
	edema	0	0
1-2	erythema	0	0
	edema	0	0
1-3	erythema	0	0
	edema	0	0
1-4	erythema	0	0
	edema	0	0

table 2: results female

female animal nr		observation time
		1-7d	8-14d
2-0	erythema	0	0
	edema	0	0
2-1	erythema	0	0
	edema	0	0
2-2	erythema	0	0
	edema	0	0
2-3	erythema	0	0
	edema	0	0
2-4	erythema	0	0
	edema	0	0

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute dermal median lethal dose (LD50) of the test item in the Wistar strain rat was found to be greater than 2000 mg/kg bw.
The test item does not meet the criteria for classification according to the Globally Harminized System of Classification and labelling of Chemicals.

Executive summary:

The acute dermal toxicity of heptamethylethyltrisiloxane was investigated in male and female RccHan:WIST rats at a dose level of 2000 mg/kg bw (24 hour exposure) followed by a 14 day observation period. There were no deaths at 2000 mg/kg bw. There were no treatment related clinical signs, nor effects on bodyweight gain with the exception of 2 females during the first week of observation. Histopathological examination revealed no effects of the test substance.

The acute dermal median lethal dose (LD₅₀) of heptamethylethyltrisiloxane in rats was found to be greater than 2000 mg/kg bw