Triethoxyhexadecylsilane

Repeated dose toxicity: oral

Administrative data

Endpoint:

sub-chronic toxicity: oral

Type of information:

experimental study planned (based on read-across)

Study period:

The test will be conducted after a decision on the requirement to carry out the proposed test has been taken according to the procedure laid down in Regulation (EC) 1907/2006 and a deadline to submit the information required has been set by the Agency.

Justification for type of information:

TESTING PROPOSAL ON VERTEBRATE ANIMALS
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity in Rodents) with a read-across substance. The testing proposal for the read-across substance is already submitted.

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out: hexadecyl(trimethoxy)silane / CAS 16415-12-6 / EC 240-464-3
- Name of the substance for which the testing proposal will be used: triethoxyhexadecylsilane / CAS 16415-13-7 / EC 240-465-9

CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION
- Available GLP studies: No adequate and reliable GLP studies addressing repeated dose toxicity are available with the test substance itself or similar substances defined according to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No. 1907/2006.
- Available non-GLP studies: No adequate and reliable non-GLP studies addressing repeated dose toxicity are available with the test substance or similar substances.
- Historical human data: not available
- (Q)SAR: Q(SAR) methods are not applicable to assess the full scope of repeated dose toxicity
- In vitro methods: No validated in vitro methods to assess repeated dose toxicity are available so far.
- Weight of evidence: So far there is no information (QSAR, in vitro data, repeated dose or fertility data) available which is suitable to assess repeated dose toxicity in a weight of evidence approach.
- Grouping and read-across: The proposed test is part of a sequential testing strategy program for alkoxysilanes which is developed in close collaboration with ECHA to minimise the need for additional animal testing.

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X (AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
In order to fulfil the standard information requirements, a GLP-compliant sub-chronic toxicity study (90-day) in rats via the oral route following OECD guideline 408 is proposed according to Annex IX, Column 1, Section 8.6.2.
Column 2 adaption possibilities at the Annex IX level where considered as follows: No reliable short term to chronic toxicity studies are available that could be used to assess repeated dose toxicity. In addition the test substance is not classified for specific target organ toxicity after repeated exposure (STOT-RE) Cat 1 or 2 in accordance with Regulation (EC) No. 1272/2008. The substance does not undergo immediate disintegration and therefore data on the cleavage products are not suitable for toxicity assessment. No adverse effects were observed in acute oral and dermal studies and no indication for irritating or sensitising properties is given. Considering the low vapour pressure of 1E-04 Pa at 20 °C (calculated) the oral route is the most suitable route to assess systemic effects.

FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
- Additional reproductive endpoints will be covered. These could include but are not limited to "Examination of reproductive organs, sperm parameters, and oestrus cycle

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

(Additional reproductive endpoints will be covered. These could include but are not limited to "Examination of reproductive organs, sperm parameters, and oestrus cycle".)

Test material

Test material information

Constituent 1

Reference substance name:

Hexadecyltrimethoxysilane

EC Number:

240-464-3

EC Name:

Hexadecyltrimethoxysilane

Cas Number:

16415-12-6

Molecular formula:

C19H42O3Si

IUPAC Name:

hexadecyl(trimethoxy)silane