Reaction mass of sulfonium, dodecylethyl[1-(2-methoxy-2-oxoethyl)-3-oxo-3-(pentyloxy)propyl]-, tetrafluoroborate(1-)(1:1) and sulfonium, dodecylethyl[3-methoxy-1-(2-methoxy-2-oxoethyl)-3-oxopropyl]-, tetrafluoroborate(1-)(1:1) and sulfonium, dodecylethyl[3-oxo-1-[2-oxo-2-(pentyloxy)ethyl]-3-(pentyloxy)propyl]-, tetrafluoroborate(1-)(1:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

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:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(1,5-dimethoxy-1,5-dioxopentan-3-yl)(dodecyl)ethylsulfanium; [1,5-dioxo-1,5-bis(pentyloxy)pentan-3-yl](dodecyl)ethylsulfanium; dodecyl(ethyl)[1-methoxy-1,5-dioxo-5-(pentyloxy)pentan-3-yl]sulfanium; tris(tetrafluoroboranuide)

EC Number:

943-993-4

Cas Number:

2220260-54-6

Molecular formula:

not applicable for multi-constituent.

IUPAC Name:

(1,5-dimethoxy-1,5-dioxopentan-3-yl)(dodecyl)ethylsulfanium; [1,5-dioxo-1,5-bis(pentyloxy)pentan-3-yl](dodecyl)ethylsulfanium; dodecyl(ethyl)[1-methoxy-1,5-dioxo-5-(pentyloxy)pentan-3-yl]sulfanium; tris(tetrafluoroboranuide)

Test material form:

liquid

Details on test material:

Multi-constituent substance.
degree of purity: >=94%

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Batch 624730
- Expiration date of the lot/batch: 2017-12
- Purity test date: 05 May, 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Stability under test conditions: No data
- Solubility and stability of the test substance in the solvent/vehicle: Dosed neat

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Dosed neat

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: No data

Source strain:

other: Not applicable

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: MatTek EpiDerm
- Tissue batch number(s): Lot No. 26717 Kit D and Lot No. 24973 Kit D (Frozen cells)
- Production date:
- Shipping date: No data
- Delivery date: 25 July, 2017
- Date of initiation of testing: 25 July, 2017

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37 C
- Temperature of post-treatment incubation (if applicable): 37 C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: Each tissue was rinsed with phosphate buffered saline (volume and number of steps were not specified).
- Observable damage in the tissue due to washing: No data

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL MTT in DMEM
- Incubation time: 3 hours
- Spectrophotometer: uQuant Plate Reader, Bio-Tek Instruments, Winooski, VT
- Wavelength: 540 nm

NUMBER OF REPLICATE TISSUES: 2 per treatment

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues / killed tissues: Frozen tissues were run concurently at the 60 minute timepoint for the test article as it reduced MTT. Control frozen tissues were run in parallel.
- Procedure used to prepare the killed tissues (if applicable): No data
- N. of replicates : 2
- Method of calculation used: Corrected Viability = VA – VB - VC
Where:
VA = Mean Viability of live tissues treated with the test article
VB = Mean Apparent Viability of frozen (dead) tissues treated with the test article
VC = Mean Apparent Viability of frozen (dead) tissues treated with TCH2O

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: The average of the values from the duplicate runs were used.

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if the viability after 3 minutes exposure is less than 50%, or if the viability after 3 minutes exposure is greater than or equal to 50 % and the viability after 1 hour exposure is less than 15%.
- The test substance is considered to be non-corrosive to skin if the viability after 3 minutes exposure is greater than or equal to 50% and the viability after 1 hour exposure is greater than or equal to 15%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 uL

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 uL

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 uL
- Concentration (if solution): 8.0 N

Duration of treatment / exposure:

3, 60 minutes

Duration of post-treatment incubation (if applicable):

3 hour MTT incubation, overnight extractant incubation.

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minute exposure

Value:

88.9

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 minutes exposure

Value:

77.6

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Based on the results of the study, MTDID 47403 is non-corrosive.

Executive summary:

The in vitro skin irritation/corrosion potential of the test article was evaluated using the MatTek EpiDerm Skin Corrosivity Test. The study was performed in compliance with GLP. The study design was based on the MatTek MTT Effective Time-50 (ET-50) Protocol (protocol no. 711-02) and OECD 431. The test article was dosed neat. Since the test article reduced MTT, frozen (dead) tissues were tested concurrently at 60 minutes and a corrected tissue viablility was calculated. EpiDerm samples were incubated in 6-well tissue culture plates containing Dulbecco's Modified Eagle's Medium (DMEM) for 1 hour. After incubation, 50 uL of the test article was applied to the tissues on top of a mesh spreading aid. The test article remained in contact with the tissue for 3 and 60 minutes. A negative control (50 uL of TCH2O) and a positive control (50 uL of potassium hydroxide solution, 8.0 N) were tested in parallel. Each treatment with test article or control was conducted in duplicate. At the end of the exposure period, each EpiDerm tissue was rinsed with phosphate buffer saline (PBS) and transferred to a 24-well microplate containing 300 uL of MTT solution (1 mg/mL MTT in Dulbecco's Modified Eagle's Medium (DMEM); a negative control, 100 uL of TCH2O was tested concurrently. Tissues were then returned to the incubator for a 3-hour MTT incubation period. Following the MTT incubation period, each EpiDerm™ tissue was rinsed with PBS and then treated overnight with 2.0 ml of extractant solution (isopropanol) per well. The absorbency of an aliquot of the extracted MTT formazan was measured in triplicate at 540 nm using a microplate reader. The mean absorbance value for each time point was calculated from the optical density (OD) of the duplicate tissues and expressed as percent viability for each sample. A mean viability at 3 minutes of greater than or equal to 50% and a mean viability at 60 minutes greater than or equal to 15% indicates the material was non-corrosive. The positive and negative controls performed as expected which indicated test validity. The corrected cell viability for tissue treated with the test material was 88.9% and 77.6% at 3 and 60 minutes, respectively.  A skin irritation potential cannot be excluded by this test and therefore the substance was classified as a Category 2 skin irritant according to the GHS criteria.