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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
08.08.1989 to 22.08.1989
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: 1a The study was conducted according to the appropriate OECD test guideline, and in compliance with GLP.

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:
OECD Guideline 401 (Acute Oral Toxicity)
Principles of method if other than guideline:
Needs proper translation as key study
GLP compliance:
yes
Test type:
standard acute method

Test material

Reference
Name:
Unnamed
Type:
Constituent
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 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:
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.
Body weight:
Needs translation
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:
harmful
Remarks:
Migrated information Criteria used for interpretation of results: EU
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.