N-sodiohexamethyldisilazane

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Information from published industry source (USEPA), limitations in design and/or reporting but otherwise adequate for assessment

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1965

Report date:

1965

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Two New-Zealand White rabbits per sex per dose group were exposed by occlusive dermal application to the test substance for 24 hours. During the observation period of 14 days, animals were examined for mortality, local reactions, and behavioral abnormalties.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,1,1,3,3,3-hexamethyldisilazane

EC Number:

213-668-5

EC Name:

1,1,1,3,3,3-hexamethyldisilazane

Cas Number:

999-97-3

Molecular formula:

C6H19NSi2

IUPAC Name:

1,1,1-trimethyl-N-(trimethylsilyl)silanamine

Details on test material:

- Name of test material (as cited in study report): Hexamethyldisilazane
- Molecular formula (if other than submission substance): C6H19NSi2

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 2.5 kg
- Housing: individual, stainless steel cages
- Diet: ad libitum Wayne Rabbit Ration, Allied Mills, Chicago, Illinois
- Water: ad libitum
- Acclimation period: 7 days

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: back, shaved with electric clippers
- % coverage: 10% of the total body
- Type of wrap if used: impervious plastic sheet, secured with taped

Duration of exposure:

24 hours

Doses:

900, 1350, 2025, 3038 mg/kg

No. of animals per sex per dose:

2

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs

Statistics:

To calculate the LD50 of the test material the techniques of Weil (Weil, Carrol S.: Tables for Convenient Calculation of Median-Effective Dose (LD50 or ED50) and Instructions in Their Use. Biometrics, Sept. 1952), Thompson (Thompson, William R.: Use of Moving Averages and Interpolation to Estimate Median-Effective Dose. Bact. Rev., Nov. 1947.), and Thompson and Weil (Thompson, William R. and Weil, Carrol S.: On the Construction of Tables for Moving Average Interpolation. Biometrics, March, 1952.) were used

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 350 mg/kg bw

Based on:

test mat.

Remarks on result:

other: Standard deviation is ±158 mg/kg

Mortality:

- No mortality observed in animals exposed to 900 mg/kg
- 2 out of 4 animals died exposed to 1350 mg/kg, which occured 8 to 16 hours after exposure
- All animals exposed to 2025 or 3038 mg/kg died, which occured 3 to 8 hours after exposure

Clinical signs:

other: - Severe tremors and salivation were exhibited by all animals exposed to 2025 or 3038 mg/kg, starting at 10 minutes after exposure and continued until death. In addition, extreme erythema and edema were noted at the 2 hour point. - Moderate tremors and sa

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information