Diethoxy(dimethyl)silane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

No test material purity is stated in the study report.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

no

Test type:

other: no standard protocol

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diethoxy(dimethyl)silane

EC Number:

201-127-6

EC Name:

Diethoxy(dimethyl)silane

Cas Number:

78-62-6

Molecular formula:

C6H16O2Si

IUPAC Name:

diethoxydimethylsilane

Details on test material:

- Name of test material (as cited in study report): Silicone A-164
- Physical state: light yellow liquid

Test animals

Species:

rat

Strain:

other: Wistar-derived

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 3 - 4 weeks
- Weight at study initiation: 90 - 120 g
- Fasting period before study: none
- Diet: ad libitum (not further specified)
- Water: ad libitum (not further specified)

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

A substantially saturated vapor is prepared by spreading 50 to 100 g of the test material over 200 cm² area on shallow tray placed near the top of a 120 L Plexiglas chamber which is then sealed for at least 16 h while an intermittently operated fan agitates the internal chamber atmosphere. Rats are then introduced in a gasketed drawer-type cage designed and operated to minimize vapor loss.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

29 - 225 min

Concentrations:

saturated vapor

No. of animals per sex per dose:

6 males

Control animals:

no

Details on study design:

- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

other: LT50

Effect level:

54 other: min

Based on:

test mat.

Remarks on result:

other: Exposure duration: 29 - 225 min

Mortality:

Mortality occurred 29 min (1/6), 57 min (3/6), 113 min (6/6) and 225 min (6/6) after exposure to a saturated vapor of the test material.

Clinical signs:

other: Clinical signs such as lacrimation, ataxia, dyspnea, prostration and audible respiration were recorded in all exposure groups.

Body weight:

Mean body weight changes seen throughout the study period were:
29 min: 56 - 79 g
57 min: 57 - 64 g
113 min: 5/6 animals died during the exposure period, 1/6 animal died 1.25 h after the exposure period
225 min: 6/6 animals died during the exposure period

Gross pathology:

Gross pathology of dead animals revealed dark red lungs and gas-filled stomachs and intestines. No abnormalities were found in surviving animals.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

An LC50 could not be established in an acute inhalation toxicity study, in which rats were exposed to a saturated vapor (concentration not report) for 29 to 225 minutes. Mortality did occur as follows at all exposure time points: 1/6 at 29 min; 3/6 at 57 min; 6/6 at 113 min; and 6/6 at 225 min. Because of the lack of data on concentration, this study cannot be used for classification.