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Diss Factsheets

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
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

Constituent 1
Chemical structure
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  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).