Dichloro(dimethyl)silane

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08.08.1989 to 22.08.1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Test material

Test material information

Constituent 1

Reference substance name:

Dichloro(dimethyl)silane

EC Number:

200-901-0

EC Name:

Dichloro(dimethyl)silane

Cas Number:

75-78-5

Molecular formula:

C2H6Cl2Si

IUPAC Name:

dichlorodimethylsilane

Details on test material:

- Name of test material (as cited in study report): Dimethyldichlorsilan
- Substance type: chlorosilane
- Physical state: Colourless 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: 7-10 weeks
- Weight at study initiation: Average maximum weights: Males 174 g; females 167 g
- Fasting period before study:
- Housing: Type III Macrolon cages (5 per cage)
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Four days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22± 2
- Humidity (%): 50±10
- Air changes (per hr): approximately 10
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: Not clear - needs translation

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

paraffin oil

Details on oral exposure:

VEHICLE - might be more information, but cannot translate
- Concentration in vehicle: No data
- Amount of vehicle (if gavage): No data
- Justification for choice of vehicle: No data
- Lot/batch no. (if required): No data
- Purity: No data


MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg bw


DOSAGE PREPARATION (if unusual): Not clear from German report

Doses:

125, 500, 707 and 1000 mg/kg bw

No. of animals per sex per dose:

Five

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observed twice daily, body weights measured before dosing, and on day 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed:gross examinations performed

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

595 mg/kg bw

Mortality:

All animals in the 1000 mg/kg bw group died approximately one hour after application. After 707 mg/kg bw animals died between three hours and five days. No animals died in the 125 and 500 mg/kg bw group.

Clinical signs:

other: Clinical signs for the 500 and 707 mg/kg bw were ruffled coat and general poor condition. At 1000 mg/kg bw rats showed ruffled fur, laboured breathing and sedation. The symptoms were mild to moderate, occurred approximately 30 minutes after dosing, and la

Gross pathology:

Gastrointestinal tract dark red or black, red pancreas, brown mottled liver in the 707 and 1000 mg/kg bw.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In an acute oral toxicity study (reliability score 1) conducted to the now deleted OECD 401 and GLP, the LD50 for dichloro(dimethyl)silane was 595 mg/kg bw in rats.

Executive summary:

In an acute oral toxicity study (reliability score 1) conducted to the now deleted OECD 401 and GLP, dichloro(dimethyl)silane (in paraffin oil) was administered by oral gavage to Wistar rats (five/sex/dose) at doses of 125, 500, 707 and 1000 mg/kg bw. Animals were then observed for 14 days, twice daily. Body weights were measured before dosing, and on days 7 and 14. All animals were examined macroscopically. All animals in the 1000 mg/kg bw group died approximately one hour after application. After 707 mg/kg bw animals died between three hours and five days. No animals died in the 125 and 500 mg/kg bw group. Clinical signs for the 500 and 707 mg/kg bw were ruffled coat and general poor condition. At 1000 mg/kg bw rats showed ruffled fur, laboured breathing and sedation. The symptoms were mild to moderate, occurred approximately 30 minutes after dosing, and lasted for up to three days or until death. After 125 mg/kg bw ruffled fur was the only clinical sign observed. All surviving animals were asymptomatic by day 4. Necropsy revealed dark red or black gastrointestinal tract, red pancreas, brown mottled liver in the 707 and 1000 mg/kg bw. The LD₅₀ was calculated to be 595 mg/kg bw.