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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
not in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1982
Report date:
1982

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Principles of method if other than guideline:
Hilltop-Wistar albino rats, weighing between 200 and 300 g, received the test material by stomach intubation with a ball-end stainless steel needle.  The sample was injected through the needle by means of a syringe and doses were varied by adjusting the volume of the test material.  The rats were fasted overnight before dosing.  Five males and 5 females were included on each level (16.0 and 8.0 ml/kg). 
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Hexamethyldisiloxane
EC Number:
203-492-7
EC Name:
Hexamethyldisiloxane
Cas Number:
107-46-0
Molecular formula:
C6H18OSi2
IUPAC Name:
trimethyl[(trimethylsilyl)oxy]silane

Test animals

Species:
rat
Strain:
other: Hilltop-Wistar albino
Sex:
male/female
Details on test animals or test system and environmental conditions:
weighing between 200 and 300 g

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
VEHICLE: Not applicable

MAXIMUM DOSE VOLUME APPLIED: Not stated
Doses:
8.0 and 16.0 ml/kg
No. of animals per sex per dose:
5/sex/group
Control animals:
no
Details on study design:
Hilltop-Wistar albino rats, weighing between 200 and 300 g, received the test material by stomach intubation with a ball-end stainless steel needle.  The sample was injected through the needle by means of a syringe and doses were varied by adjusting the volume of the test material.  The rats were fasted overnight before dosing.  Five males and 5 females were included on each level (16.0 and 8.0 ml/kg).  The animals were maintained on appropriate commercial diet and municipal water.  Both were available ad libitum except during period of fasting, manipulation or restraint.   Animal weights were recorded at 0 days (before dose), 7 days and 14 days (just prior to sacrifice).  At death or sacrifice, each animal was subjected to gross pathologic evaluation.
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
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 16 mL/kg bw
Based on:
test mat.
Remarks on result:
other: corresponding to 12.16 g/kg
Mortality:
MALES:
 16.0 ml/kg Dead/Dosed: 0/5
8.0 ml/kg Dead/dosed: 1/5

FEMALES:
 16.0 ml/kg Dead/Dosed: 0/5
8.0 ml/kg Dead/Dosed: 0/5
Clinical signs:
other: MALES: 16.0 ml/kg  None noted.  8.0 ml/kg: In the animal that died, sluggishness, unsteady gait at 4 min; death at 15 min.  In survivors, none noted. FEMALES:  16.0 ml/kg None noted. 8.0 ml/kg  None noted.
Gross pathology:
MALES:
 16.0 ml/kg : Nothing remarkable.
 8.0 ml/kg  In animal that died, lungs with dark spots; liver dark; stomach liquid-filled, injected; intestines and kidneys red.  In survivors, nothing remarkable.

FEMALES:
 16.0 ml/kg : Nothing remarkable.
8.0 ml/kg  Nothing remarkable.
Other findings:
No other findings reported.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The acute oral LD50 was determined to be > 16.0 ml/kg, dosed as received, in both male and female rats.