chloro(methyl)silanes and tetramethylsilane and trichlorosilane from the fractionated distillation of the reaction products of silicon and chloromethane

Acute Toxicity: oral

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:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: 2e The study was well documented and meets generally accepted scientific principles, but was not conducted in compliance with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

not specified

Remarks:

Although a GLP statement was not included with the report, it is known that Bushy Run Research Center (BRRC) operated as a GLP facility at the time the testing was conducted.

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dichloro(methyl)silane

EC Number:

200-877-1

EC Name:

Dichloro(methyl)silane

Cas Number:

75-54-7

Molecular formula:

CH4Cl2Si

IUPAC Name:

dichloro(methyl)silane

Details on test material:

- Name of test material (as cited in study report): Organochlorosilane A-155
- Substance type: chlorosilane
- Physical state: clear yellow liquid
- Expiration date of the lot/batch: No data
- Stability under test conditions: No data
- Storage condition of test material: No data

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Weight at study initiation: 200 and 300 g
- Fasting period before study: overnight prior to dosing
No further details available

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: some undiluted, some in L-45 oil

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 8.0 ml/kg

Doses:

0.25 (undiluted), 2.0 (males), 4.0, 5.7 (females), 8.0 (25% diluted in L-45 oil) ml/kg

No. of animals per sex per dose:

5/sex/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Weights were recorded immediately prior to dosing and on days 7 and/or 14 of the observation period.
- Necropsy of survivors performed: yes

Statistics:

LD50s were calculated by the moving average method (Thompson, 1947) and were based on a 14-day observation period.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

< 0.25 mL/kg bw

Remarks on result:

other: undiluted

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

2.83 mL/kg bw

95% CL:

>= 1.85 - <= 4.32

Remarks on result:

other: 25% solution in L-45 oil

Effect levels 3

Sex:

female

Dose descriptor:

LD50

Effect level:

4.73 mL/kg bw

95% CL:

>= 4.05 - <= 5.53

Remarks on result:

other: 25% solution in L-45 oil

Mortality:

Undiluted: Dead/Dosed: Males: 4/5; Females: 5/5

25% oil solution: Males: 3/5, 4/5, and 0/5 at 8.0, 4.0, and 2.0 mL/kg bw
Females: 5/5, 5/5, and 0/5 at 8.0, 5.7, and 4.0 mL/kg bw

Clinical signs:

other: Undiluted: Males: Death of 1 rat within 3.5 hours Females: Sluggishness at 3 hr 25% oil solution: Males: At 8.0 mL/kg bw:: Breathing difficulty at 2 min; death of 3 at 12 to 20 min. At 4.0 mL/kg bw:: Sluggishness at 10 min; death of 3 at 1.5 hr; survi

Gross pathology:

Undiluted: Males: In animals that died, livers dark; spleens enlarged; stomachs black; intestines red; adrenals red or black. In survivor, kidneys fluid-filled.
Females: In animals that died, Lungs dark red; livers black; stomachs black or red; kidneys dark; intestines blod-filled; adrenals red.

25% solution:
Males: At 8.0 mL/kg bw: In animals that died, stomachs distended, walls brittle, liquid-filled, glandular portions injected; livers brown-red; intestines brown with hardened areas; kidneys hard and brown; spleens enlarged.  In survivors, nothing remarkable.
At 4.0 mL/kg bw: In animals that died, stomachs liquid-filled, injected, glandular portions black; livers dark near stomach; intestines red, injected; kidneys tan near stomach; spleens enlarged; pancreata red.  In survivor, pancreatic lymph nodes enlarged; stomach adhered to liver and abdominal wall.
At 2.0 mL/kg bw: Nothing remarkable

Females: At 8.0 mL/kg bw: Stomachs liquid-filled, injected, glandular portions black; livers pale, hard in sections near stomach; intestines red, injected; kidneys tan, hard near stomach; spleens enlarged; pancreata tan.
At 5.7 mL/kg bw: Mucosal surface of stomachs smooth; livers mottled maroon, gray and brown; cortical surfaces of kidneys mottled maroon, gray and brown.
At 4.0 mL/kg bw: Nothing remarkable

Any other information on results incl. tables

Based on the results of this study, a subsequent study using a dilution of the test material was conducted.

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 in rats (reliability score 2), which was comparable to OECD 401, the LD50 for undiluted organochlorosilane A-155 was less than 0.25 ml/kg bw. The LD50s for a 25% dilution of organochlorosilane in L-45 oil were 2.83 ml/kg bw and 4.73 for males and females, respectively.

Executive summary:

In an acute oral toxicity study in Wistar rats (reliability score 2), which was comparable to OECD 401, the LD₅₀ for undiluted organochlorosilane A-155 was less than 0.25 ml/kg bw. The LD₅₀s for a 25% dilution of organochlorosilane in L-45 oil were 2.83 ml/kg bw and 4.73 for males and females, respectively. Following an oral gavage dose of undiluted test substance all animals died within 3.5 hours. All deaths following administration of diluted test substance occurred within two hours. Sluggishness was the main clinical sign of toxicty, but there were also some instances of dyspnea, unsteady gait and prostration. Gross necropsy mainly revealed discoloured, fluid-filled and/or enlarged organs (liver, spleen, intestines, stomach, kidneys).