2,2,4,4,6,6-hexamethylcyclotrisilazane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1988-08-11 to 1989-02-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The restrictions were that the test concentration was not the maximum concentration for vapours and no analythical verification of the test concentration was performed.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1989

Report date:

1989

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

1981

Deviations:

yes

Remarks:

The study does not meet current guideline requirements.

GLP compliance:

yes

Test type:

traditional method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2,4,4,6,6-hexamethylcyclotrisilazane

EC Number:

213-773-6

EC Name:

2,2,4,4,6,6-hexamethylcyclotrisilazane

Cas Number:

1009-93-4

Molecular formula:

C6H21N3Si3

IUPAC Name:

2,2,4,4,6,6-hexamethyl-1,3,5,2,4,6-triazatrisilinane

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Basic Material Business, BB058016

FORM AS APPLIED IN THE TEST (if different from that of starting material): vapour

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, USA
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: no data
- Weight at study initiation: 175 - 200 g
- Fasting period before study: no data
- Housing: In stainless steel, wire mesh bottomed cages of convensional design
- Diet: ad libitum except during the exposure period
- Water: ad libitum except during the exposure period
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30 - 50 %
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Remark on MMAD/GSD:

No data

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Stainless steel and glass chamber
- Exposure chamber volume: 450-liter
- Method of holding animals in test chamber: no data
- Source and rate of air: Air passed through a J-tube and rate of the airflow was monitored by Magnehelic gauges. A glass J-tube with a low flow FMI Lab pump was used to introduce test material into the chamber. Filtered laboratory air passed through the J-tube. The air/ vapour mixture entered the top of the chamber where it was diluted with room air. Heating tape was used to heat the air which passed through the J-tube, and glass beads were used to help vaporise the test material.
- Method of conditioning air: Matheson 462 cartridge filter
- Treatment of exhaust air: the exhaust air was filtered (hepa and carbon), cleaned with a water cyclone, then exhausted from the roof of the building.
- Temperature, humidity, pressure in air chamber: Chamber temperature and relative humidity were monitored with Cole-Primer Model No. 3310-40 (certified) temperature and humidity gauges.
- A glass J-tube with a low flow FMI Lab pump was used to introduce test material into the chamber. Filtered laboratory air passed through the J-tube. The air/ vapour mixture entered the top of the chamber where it was diluted with room air. Heating tape was used to heat the air which passed through the J-tube, and glass beads were used to help vaporise the test material.

TEST ATMOSPHERE
- Brief description of analytical method used: no data
- Samples taken from breathing zone: no


TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: no data
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): no data

Analytical verification of test atmosphere concentrations:

not specified

Remarks:

The calculated nominal concentration was 4.9 mg/L. The actual exposure concentration was slightly less than the calculated value due to condensation of the test material.

Duration of exposure:

4 h

Remarks on duration:

The exposure period lasted 4 hours after chamber equilibration.

Concentrations:

5.0 mg/L

No. of animals per sex per dose:

5 males and 5 females

Control animals:

yes

Remarks:

The control group was exposed to filtered room air.

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed once a day during weekdays. Individual animal body weights were measured prior to the treatment, then on days 7 and 14 after exposure. - Necropsy of survivors performed: no data
- Other examinations performed: clinical signs and body weight

Statistics:

Not used

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

>= 4.9 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No mortality occurred during the 14-day study period.

Clinical signs:

other: No clinical signs of toxicity were observed in any of the test animals.

Body weight:

No test-materal related effects on body weights.

Gross pathology:

No data.

Other findings:

No other findings were reported.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In the acute inhalation toxicity study, conducted according to a former version of OECD test guideline, and in compliance with GLP, no LC50 value was reported due to lack of toxic effect observed in any of the test animals.