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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:
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

Constituent 1
Chemical structure
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 levelsopen allclose all
Sex:
male/female
Dose descriptor:
LD50
Effect level:
< 0.25 mL/kg bw
Remarks on result:
other: undiluted
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
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:
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; survivor recovered at 1.5 hr.
At 2.0 mL/kg bw: None noted

Females: At 8.0 mL/kg bw: Sluggishness at 5 min; death of 5 within 2 hr.
At 5.7 mL/kg bw: Sluggishness, unsteady gait at 3 min; prostration at 15 min; death of 5 at 30 to 45 min.
At 4.0 mL/kg bw: None noted
Body weight:
Undiluted: Males: In the one survivor: 7 days = 47 g; 14 days = 103 g
Females: No survivors

25% oil solution:
Males: At 8.0 mL/kg bw: In 2 survivors: at 7 days = 66 and 72; at 14 days = 97 and 111
At 4.0 mL/kg bw: In one survivor: at 7 days = -9; at 14 days = 59
At 2.0 mL/kg bw: In survivors: at 7 days = 60 to 91; at 14 days = 82 to 132

Females: At 8.0 mL/kg bw: No survivors
At 5.7 mL/kg bw: No survivors
At 4.0 mL/kg bw: In survivors: at 7 days = 18 to 34; at 14 days = 24 to 41
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).