Dicyclopentyldimethoxysilane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06.11.1992 to 11.06.1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Only one dose tested

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dicyclopentyldimethoxysilane

EC Number:

404-370-8

EC Name:

Dicyclopentyldimethoxysilane

Cas Number:

126990-35-0

Molecular formula:

C12H24O2Si

IUPAC Name:

dicyclopentyldimethoxysilane

Test material form:

liquid

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data
- Age at study initiation: 6-8 weeks
- Weight at study initiation: 155-195 g
- Fasting period before study: No
- Housing: Stainless steel cages
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Seven days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22± 2
- Humidity (%): 50± 20
- Air changes (per hr): No data
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 19.11.1992 To: 07.12.1992

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus and chamber volume: 450 litre stainless steel and glass exposure chambers.
- Method of holding animals in test chamber: None
- Source and rate of air: Ambient filtered with hepa and charcoal filters. 12-15 air changes per hour.
- Treatment of exhaust air: No data
- Temperature, humidity, pressure in air chamber: Recorded every five minutes during the exposure period.

TEST ATMOSPHERE
- Brief description of analytical method used: Chamber concentrations were measured at least once per hour by a Varian 3400 Gas Chromatography.
- Samples taken from breathing zone: No data

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Nominal: 33 ppm
Actual: 22 ppm
The saturated vapour concentration is approximately 52 ppm. The target exposure concentration of 30 ppm appears to have been unattainable under the conditions of this study as evidenced by the test substance deposition within the vapour generating and the gas chromatography sampling system.

No. of animals per sex per dose:

Five

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observed daily during the post-exposure period for clinical signs, mortality, general appearance and any evidence of respiratory, dermal, behavioural, nasal or ocular changes. Animals were weighed on days 1, 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: Gross pathological examination was conducted on all animals. The kidneys were examined microscopically.

Statistics:

Statistical analyses were conducted on body weights. Data were analysed by a two-sided Welch Trend Test. All tests were conducted at the P≤ 0.05 level of significance.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 22 ppm

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: No deaths.

Mortality:

No animals died.

Clinical signs:

other: None

Body weight:

No effects on body weights.

Gross pathology:

Pale kidneys were observed in 9/10 animals.

Other findings:

Histopathological examination of pale kidneys did not reveal any correlative microscopic lesions.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

In an acute inhalation study conducted using a protocol similar to OECD Test Guideline 403 and in compliance with GLP, the LD50 for dicyclopentyl(dimethoxy)silane was greater than 22 ppm, as no deaths occurred following a 4-hour exposure to this concentration. This concentration appeared to be the highest attainable under the conditions of this study.