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

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03.06.80 to 05.08.80

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline. It was not compliant with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

Study was conducted prior to the adoption of OECD test guidelines and GLP

GLP compliance:

no

Remarks:

Pre-GLP

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:

bis(trimethylsilyl)amine

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: No data
- Weight at study initiation: No data
- Fasting period before study: Yes, but period not given.
- Housing: Groups of 5 in Makrolon Type II cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: No data


ENVIRONMENTAL CONDITIONS
- Temperature (°C):22 ±2
- Humidity (%): 60 ±5
- Air changes (per hr): about 10
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 03.06.80 To: 05.08.80

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 1.5 ml/kg bw

Doses:

0.1, 1.0, 1.2, 1.4 and 1.5 ml/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: Daily observations and weighing once per week.
- Necropsy of survivors performed: yes
- Other examinations performed: Not clear

Statistics:

The acute oral LD50 was determined by probit-regression analysis.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1.1 mL/kg bw

95% CL:

>= 1 - <= 1.2

Remarks on result:

other: equivalent to 847 mg/kg bw based on a density of 0.77 g/cm³

Mortality:

See Table 1.

Clinical signs:

other: At doses of 1.0 ml/kg bw and above paralysis of hind limbs, sedation, anaesthesia and poor general condition were observed.

Gross pathology:

Redness of the stomach mucosal membrane among animals that died during the study and those sacrificed at the end of the observation period.

Other findings:

None reported

Any other information on results incl. tables

Table 1 Summary of mortality

Dose (ml/kg bw)	Dead/dosed	Days to death	Mortality (%)
Males
0.1	0/5	-	0
1.0	2/5	3	40
1.2	1/5	2	20
1.4	5/5	4	100
1.5	5/5	2	100
Females
0.1	0/5	-	0
1.0	2/5	3	40
1.2	4/5	4	80
1.4	4/5	7	80
1.5	5/5	2	100

 

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In an acute oral toxicity study with 1,1,1,3,3,3-hexamethyldisilazane (CAS 999-97-3), conducted according to a protocol comparable to the now-deleted OECD Test Guideline 401 but without information on GLP compliance, the LD50 was concluded to be 1.1 ml/kg bw/day (equivalent to 847 mg/kg bw based on a density of 0.77 g/cm³).