Dicyclopentyldimethoxysilane

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

short-term repeated dose toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

06.11.1992 to 11.06.1993

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

documentation insufficient for assessment

Remarks:

The study did not meet current guideline requirements for repeated dose toxicity studies. It does, however, add weight of evidence for this endpoint.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

yes

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

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Remarks on MMAD:

MMAD / GSD: N/A

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

6 hours

Frequency of treatment:

Daily for four days

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
1, 5 or 24 ppm
Basis:
analytical conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
1, 5 or 30 ppm
Basis:
other: Target conc.

No. of animals per sex per dose:

FIve

Control animals:

yes, concurrent vehicle

Results and discussion

Effect levels

1

Dose descriptor:

NOAEC

Effect level:

>= 24 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Based on there being no systemic effects.

2

Dose descriptor:

NOAEC

Effect level:

5 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Based on local effects on the lung.

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

No mortality or overt signs of toxicity observed during exposure or observation periods. Terminal sacrifice did not reveal any test substance related effects. There were no effects on absolute or relative organ weights. Microscopic examination of the tissues and organs revealed a weak treatment-related effect consisting of chronic inflammation characterised by alveolar infiltrates of macrophages and minor involvement of the trachea in the rats exposed to 24 ppm. In the 1 and 5 ppm groups there was a less frequent incidence of chronic inflammation and less severity of the lesion, which was similar to the control lungs.

Applicant's summary and conclusion

Conclusions:

Following a four-day repeated inhalation of dicyclopenty(ldimethoxy)silane up to a maximum attainable vapour concentration of 24 ppm, there were no systemic effects in rats. There were local effects on the lungs at 24 ppm, which consisted of chronic inflammation characterised by alveolar infiltrates of macrophages and minor involvement of the trachea (reliability score 4).