Dimethoxymethylsilane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 Aug - 30 Dec 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

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 403 (Acute Inhalation Toxicity)

Version / remarks:

(1981)

Deviations:

yes

Remarks:

(no gross necropsy was done at the end of the observation period, no justification for the use of a whole-body inhalation system is given)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dimethoxymethylsilane

EC Number:

240-914-9

EC Name:

Dimethoxymethylsilane

Cas Number:

16881-77-9

Molecular formula:

C3H10O2Si

IUPAC Name:

Dimethoxy(methyl)silane

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Methyldimethoxysilane
- Lot/batch No.: A80530

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
- Weight at study initiation: 175 - 200 g
- Housing: in stainless steel wire mesh bottomed cages
- Diet: Purina rodent chow, ad libitum, except during exposure
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30 - 50
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

clean air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: stainless steel and glass exposure chamber under dynamic conditions. Airflow rates through the chambers were monitored continously by calibrated Magnehelic gauges connected across orifices at the chamber inlets. Chamber temperature and relative humidity were monitored with cole-Parmer Model No. 3310-40 (certified) temperature and humidity gauges. Gauge readings were recorded hourly during the exposure period.
- Exposure chamber volume: 450 L
- Source and rate of air: laboratory air
- Method of conditioning air: the test material was introduced into the test chamber through a specially designed glass J-tube with a flow FMI Lab pump. Laboratory air filtered and dried with Matheson #462 cartridge filter passed through the J-tube. The air/vapor 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 further help vaporize the test material.
- Treatment of exhaust air: the exhaust air was filtered (hepa and carbon) cleaned with water cyclone and then exhausted from the roof of the building.

TEST ATMOSPHERE
- Brief description of analytical method used: airflow rates through the chambers were monitored continuously by calibrated Magnehelic gauges connected across orifices at the chamber inlets. Gauge readings were recorded hourly during the exposure period. Chamber temperature and relative humidity were monitored with Cole-Parmer Model No. 3310-40 (certified) temperature and humidity gauges. Gauge readings were recorded hourly during the exposure period.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

calculated by weight

Duration of exposure:

4 h

Concentrations:

5000 mg/m³ (nominal), 4600 mg/m³ (analytical)

No. of animals per sex per dose:

5 males and females

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: animals observed daily on weekdays, body weight was determined prior to exposure and on Day 7 and 14 post exposure
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4 600 mg/m³ air (analytical)

Based on:

test mat.

Remarks:

calculated by weight

Exp. duration:

4 h

Remarks on result:

other: no adverse effects or mortalities were observed

Mortality:

No mortalities were observed during the study period.

Clinical signs:

other: No other clinical signs were observed during the study period.

Body weight:

No effects on body weight were observed during the study period.

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008

Conclusions:

In conclusion, under the conditions chosen for this experiment (according to OECD 403), the test substance was found not to be toxic by inhalation, since no mortalities or clinical signs of toxicity were observed at the maximum attainable concentration.