Trimethylvinylsilane

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in chemico

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 442C (In Chemico Skin Sensitisation: Direct Peptide Reactivity Assay (DPRA))

Version / remarks:

Feb. 4, 2015

GLP compliance:

yes (incl. QA statement)

Type of study:

direct peptide reactivity assay (DPRA)

Test material

Test material information

Constituent 1

Reference substance name:

Trimethylvinylsilane

EC Number:

212-042-9

EC Name:

Trimethylvinylsilane

Cas Number:

754-05-2

Molecular formula:

C5H12Si

IUPAC Name:

trimethylvinylsilane

Specific details on test material used for the study:

purity: 99.59%

In chemico test system

Details on the study design:

TEST-SUBSTANCE PREPARATION
- Stock solution: 100 mM
- Vehicle: acetonitrile
- Reason for the vehicle: The test substance is soluble in acetonitrile

CONTROLS
- Reference controls: acetonitrile
- Co-elution control: buffer and test substance without the peptide
- Positive control: cinnamic aldehyde in acetonitrile

PEPTIDES
Synthetic peptides:
- Cysteine- (C-) containing peptide: Ac-RFAACAA
- Lysine- (K-) containing peptide: Ac-RFAAKAA
Stock solution:
- C-containing peptide: 0.667 mM of peptide in pH 7.5 phosphate buffer
- K-containing peptide: 0.667 mM of peptide in pH 10.2 ammonium acetate buffer
Ratios
- C-containing peptide: ratio of 1:10
- K-containing peptide: ratio of 1:50

EXPERIMENTAL PROCEDURE
- Replicates: 3 for each peptide
- Determination remaining non-depleted peptide concentration: HPLC at 220nm: HPLC analysis st
arted 24 to 26 hours after sample preparation and the analysis time was less than 30 hours.
- Calibration samples: samples of a known peptide concentration are measured in parallel

PREPARATIONS SAMPLES
- Calibration sample was prepared from the peptide stock solution (0.667 mM) in acetonitrile in the respective buffer using serial concentrations of 0.534 - 0.017 mM peptide.
- Test-substance samples: samples were incubated at 25°C +/- 2.5°C in the dark for 24 +/- 2 hours and visually investigated for any precipitate that may occur during the exposure period.
- Preparation of vehicle control: in triplicated in the same way as the test-substance samples described above but with acetonitrile instead of the test substance.
- Preparation of co-elution control: in the same way as the test-substance sampled described above but without the peptide, instead buffer was used.

MEASUREMENT PEPTIDE CONCENTRATIONS
- Method: HPLC Agilent 1200 Series
- Wavelength: 220 nm and 258 nm
- Detection: UV Detector

DATA EVALUATION
The concentration of the cysteine an lysine peptide is determined in each sample from absorbance at 220 nm, measuring the area of the appropriate peaks (peak area (PA)) and calculating the concentration of peptide using the linear calibration curves derived from the standard solutions. The percent peptide depletion (PPD) is calculated as:
(1- (Peptide Peak Area in the Replicate Injection/Mean Peptide Peak Area in the Reference Control C))*100

ACCEPTANCE CRITERIA
- the standard calibration curve should have an r2 > 0.99
- the mean PPD value of the three replicates for the positive control is between 60.8% and 100% for the cysteine peptide and the maximum standard deviation (SD) for the positive control replicates is < 14.9%
- the mean PPD value of the three replicates for the positive control is between 40.2% and 69.0% for the lysine peptide and the maximum SD for the positive control replicates is < 11.6%
- the mean peptide concentration of the three reference control A replicatres is 0.50 +/- 0.05 mM
- the coefficient of variation (CV) of nine vehicle controls B and C should be < 15%

EVALUATION RESULTS
Chemical reactivity was determined by mean peptide depletion [%] and was rated as
- high: mean peptide depletion > 42.47
- moderate: mean peptide depletion > 22.62 ≤ 42.47
- low: mean peptide depletion > 6.38 ≤ 22.62
- minimal: mean peptide depletion ≤ 6.38
High, moderate and low reactivity are evaluated as positive.

In case the mean peptide depletion cannot be determined due to invalid K-peptide depletion the evaluation is performed as follows:
- high: mean peptide depletion > 98.24
- moderate: mean peptide depletion > 23.09 ≤ 98.24
- low: mean peptide depletion > 13.89 ≤ 23.09
- minimal: mean peptide depletion ≤ 13.89
High, moderate and low reactivity are evaluated as positive.

Results and discussion

In vitro / in chemico

Results

Results 1

Key result

Run / experiment:

mean

Parameter:

other: Lysine peptide depletion

Value:

0

Negative controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Run / experiment:

mean

Parameter:

other: Cysteine peptide depletion

Value:

0

Negative controls validity:

valid

Remarks on result:

no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:

other: No indication of skin sensitisation potential.

Executive summary:

The skin sensitisation potential of trimethylvinylsilane was assessed via the in vitro DPRA assessment in accordance with OECD guideline 442C.

The test item exhibited a mean lysine peptide depletion of 0% and a mean cysteine peptide depletion of 0%.

Hence, the DPRA assessment does not indicate for the substance to have a potential for skins sensitisation.