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

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 March to 25 March 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

17 December 2001

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Version / remarks:

30 September 1996

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

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

Details on test material:

Other name: Baysilone TP 3886

Specific details on test material used for the study:

Specific density: 828 g/L at 20°C
Storage condition: ambient temperature

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Crl: (WI) WU BR

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 7 - 8 weeks
- Weight at study initiation: 166 -180 g
- Fasting period before study: Prior to dosing, fasted overnight until approx. 4h after dosing
- Housing: maximum of six animals per macrolon cage
- Diet (e.g. ad libitum): standard laboratory diet ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/-3°C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12h/12h

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

Administered dose volume: 2.42 mL/kg bw

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observations 1h, 4h after dosing, subsequently daily; weighing on day 0, 3, 7 and 14
- Necropsy of survivors performed: yes

Statistics:

Not conducted

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

no mortality

Clinical signs:

other: no clinical signs (with exception of tremors in 3 animals 1 hour after dosing only)

Gross pathology:

no findings

Any other information on results incl. tables

Table 1: Acute oral toxicity of the test item in rats, individual and mean body weights, doses amounts applied and mortality

Animal no	Dose applied [mL]	Body weights [g] recorded on day:				Mortality [dead/survived]
		0	3	7	14
2000mg/kg bw (first group)
41	0.43	180	195	197	207	--
43	0.42	174	186	194	212	--
45	0.41	169	186	189	201	--
mean		174	189	193	203	0/3
2000mg/kg bw second group)
59	0.4	166	183	187	198	--
61	0.41	170	190	197	213	--
63	0.43	180	196	205	210	--
		172	190	196	207	0/3

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LD50 for oral toxicity to female rats was determined to be > 2000 mg/kg bw. The substance is not classified according to CLP criteria.

Executive summary:

The acute oral (gavage) toxicitity of heptamethylethyltrisiloxane was investigated in female Wistar derived rats at a dose level of 2000 mg/kg bw followed by a 14 day observation period. The test substance was dosed undiluted. There were no deaths at 2000 mg/kg bw, therefore no further testing was required. There were no treatment related clinical signs, and all animals gained bodyweight during the observation period. Examination at necropsy revealed no effects of the test substance.

The acute oral median lethal dose (LD₅₀) of heptamethylethyltrisiloxane in rats was found to be greater than 2000 mg/kg bw therefore the substance is not classified according to CLP criteria.