Hydroxytrimethylsilane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12.03.1985 to 06.05.1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1985

Report date:

1985

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

No information on test substance purity.

GLP compliance:

not specified

Remarks:

Therefore assumed not to GLP

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hydroxytrimethylsilane

EC Number:

213-914-1

EC Name:

Hydroxytrimethylsilane

Cas Number:

1066-40-6

Molecular formula:

C3H10OSi

IUPAC Name:

hydroxytrimethylsilane

Details on test material:

- Name of test material (as cited in study report): Trimethylsilanol
- Substance type: Alkylsilane
- Physical state: Liquid

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, Borchen
- Age at study initiation: Nine weeks for males and 14 weeks for females.
- Weight at study initiation: Male had an average weight of 174g and the females 169g.
- Fasting period before study: 16 hours before treatment until 4 hours after.
- Housing: No data
- Diet (e.g. ad libitum): Withdrawn approximately 16 hours before until four hours after treatment. Otherwise assumed to be ad libitum.
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: No data


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22± 1.5
- Humidity (%): 60± 5
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: Not included, but study dates were 12.03.1985 to 06.05.1985

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 6.3 ml/kg bw

Doses:

0.5, 1.0, 2.0, 3.1, 5.0, 6.3 ml/kg bw

No. of animals per sex per dose:

Five

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations twice daily, and weighing before treatment, and at the end of the 14 day observation period.
- Necropsy of survivors performed: yes
- Other examinations performed: histopathology of all animals.

Statistics:

LD50 with confidence limit of p<0.05 was calculated.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

3.5 mL/kg bw

Based on:

test mat.

95% CL:

>= 2.9 - <= 4.2

Mortality:

0, 0, 10, 40, 70 and 100 %, respectively.

Clinical signs:

General deterioration in health, anaesthesia, lateral position, ruffled fur. All surviving animals appeared symptom-free after ten days.

Body weight:

There was a reduction in body weight gain.

Gross pathology:

In animals that died 'elapsed' gastric mucosa was observed (this is direct Google translation, not sure what this actually means - maybe eroded?). No other findings.

Other findings:

None reported.

Applicant's summary and conclusion

Interpretation of results:

Category 5 based on GHS criteria

Remarks:

The substance is not classified for acute oral toxicity according to Regulation (EC) No 1272/2008

Conclusions:

In an acute oral toxicity study conducted using a protocol comparable to the now deleted OECD 401, but not to GLP (reliability score 2) the LD50 for trimethylsilanol was 3.5 ml/kg bw (2835 mg/kg bw based on a density of 0.81 g/cm3) in rats (0, 0, 10, 40, 70 and 100% mortality at 0.5, 1.0, 2.0, 3.1, 5.0, 6.3 ml/kg bw). There was a general deterioration in the animals' health, anaesthesia, lateral position, ruffled fur. All surviving animals appeared symptom-free after ten days.