1-Propanethiol, 3-(trimethoxysilyl)-, adduct with 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (1:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation / corrosion

Remarks:

in vitro

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-05-14 to 2009-05-15

Reliability:

1 (reliable without restriction)

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: OECD Guidelines for the Testing of Chemicals Part 431, adopted 13. Apr. 2004, In vitro Skin Corrosion: Human Skin Model Test

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3,3,12,12-tetramethoxy-2,13-dioxa-7,8-dithia-3,12-disilatetradecane; 5-(7,7-dimethoxy-2-oxo-8-oxa-3-thia-1-aza-7-silanonan-1-yl)-1-[(7,7-dimethoxy-2-oxo-8-oxa-3-thia-1-aza-7-silanonan-1-yl)methyl]-1,3,3-trimethylcyclohexane; [3-({[(3-isocyanato-3,5,5-trimethylcyclohexyl)methyl]carbamoyl}sulfanyl)propyl]trimethoxysilane; [3-({[(5-isocyanato-1,3,3-trimethylcyclohexyl)methyl]carbamoyl}sulfanyl)propyl]trimethoxysilane

EC Number:

700-534-0

Cas Number:

117172-56-2

Molecular formula:

Not applicable: UVCB substance, see section 1.2 and 1.4. The UVCB substance consits of differnt products consiting of differnt isomers: Product I and Product II cannot analytically be distinguished and moreover, Product I-III are expected to consist of isomers that can neither analytically be identified nor quantified.

IUPAC Name:

3,3,12,12-tetramethoxy-2,13-dioxa-7,8-dithia-3,12-disilatetradecane; 5-(7,7-dimethoxy-2-oxo-8-oxa-3-thia-1-aza-7-silanonan-1-yl)-1-[(7,7-dimethoxy-2-oxo-8-oxa-3-thia-1-aza-7-silanonan-1-yl)methyl]-1,3,3-trimethylcyclohexane; [3-({[(3-isocyanato-3,5,5-trimethylcyclohexyl)methyl]carbamoyl}sulfanyl)propyl]trimethoxysilane; [3-({[(5-isocyanato-1,3,3-trimethylcyclohexyl)methyl]carbamoyl}sulfanyl)propyl]trimethoxysilane

Constituent 2

Reference substance name:

Reaction products of 3- (trimethoxysilyl)propane-1-thiol and 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (1:1)

IUPAC Name:

Reaction products of 3- (trimethoxysilyl)propane-1-thiol and 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane (1:1)

Details on test material:

- Name of test material: Intermediate 36
- Colour: light yellow
- Physical state: liquid
- Purity: >99%

Test animals

Species:

human

Test system

Type of coverage:

open

Preparation of test site:

other: EpiDerm Skin Model (EPI-200)

Vehicle:

unchanged (no vehicle)

Controls:

other: not applicable

Duration of treatment / exposure:

3 minutes and one hour

Observation period:

not applicable

Number of animals:

not applicable

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: cell viability

Basis:

mean

Time point:

other: 3 minutes

Remarks on result:

other: 83.6 % referring to negative control

Results 2

Irritation parameter:

other: cell viability

Basis:

mean

Time point:

other: 1 hour

Remarks on result:

other: 92.8 % referring to negative control

Other effects:

not applicable

Any other information on results incl. tables

Irritant / Corrosive response data:

The value of the positive control induced a decrease in the relative absorbance as com-pared to the negative control to 24.5% for the three minutes treatment interval and 14.9% for the one hour treatment interval thus ensuring the validity of the test system. For these reasons, the result of the test is considered valid.

The values of the negative control were well above the required acceptability criterion of mean OD > 0.8 for both treatment interval thus showing the quality of the tissues.

After three minutes treatment, the relative absorbance values were decreased to 83.6%. This value is well above the threshold for corrosivity (50%). After one hour treatment rela-tive absorbance values were reduced to 92.8%. This value is well above the threshold for corrosivity (15%). Thus, the test item is considered as not corrosive.

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive / irritant

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Due to the absence of corrosive effects in this in vitro study, Intermediate 36 is considered not corrosive. In general, this in vitro study type does neither provide adequate information on skin irritation, nor allow the subcategorisation of corrosive substances as permitted in the Globally Harmonised Classification System (GHS). Because of the lack of irritating potential in the actual study, an in vivo study on skin irritation according to EU method B.4 resp. OECD 404 was performed additionally.

Executive summary:

The study procedure employed a human skin model and was based on the following guidelines - Organisation for Economic Co-operation and Development (OECD), OECD Guidelines for Testing of Chemicals, Draft Proposal for a new guideline no. 431: In Vitro Skin Corrosion: Human Skin Model Test (Draft 20 February 2004). - European Economic Community (EEC). Adapting to technical progress for the twenty-sixth time Annex V of the EEC Directive 67/548/EEC, Part B: Methods for the Determination of Toxicity; B.40: "Skin corrosion". EEC Publication Commission Directive (08-06-2000). The study evaluates the corrosive properties of test substance on a human three dimensional epidermal model (EpiDerm (EPI- 200)). The possible corrosive potential of the test substance was tested through topical application for 3 minutes and 1 hour exposure. 50 µL of Intermediate 36 was applied unchanged (undiluted) directly on top of the skin tissue. The test substance was dissolved in the H2O demin and spread over the tissue. The positive control (Potassium hydroxide, 8.0 mol/L) induced a decrease in the relative absorbance as compared to the negative control to 24.5% for the three minutes treatment interval and 14.9% for the one hour treatment interval thus ensuring the validity of the test system. For these reasons, the result of the test is considered valid. The values of the negative control were well above the required acceptability criterion of mean OD > 0.8 for both treatment interval thus showing the quality of the tissues. Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3 minutes and 1 hour treatment with the test substance compared to the negative control tissues was 83.6 % and 92.8 %, respectively. Since the mean relative tissue viability for the test substance was not below 50 % after 3 minutes treatment and not below 15 % after 1 hour treatment the test substance is considered to be not corrosive.