Chinomethionate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 to 31 August 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: Human Skin Model Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Chinomethionate

EC Number:

219-455-3

EC Name:

Chinomethionate

Cas Number:

2439-01-2

Molecular formula:

C10H6N2OS2

IUPAC Name:

6-methyl-2H-[1,3]dithiolo[4,5-b]quinoxalin-2-one

Test material form:

solid: particulate/powder

Remarks:

Yellow powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Bx 160722-01
- Expiration date of the lot/batch: 22 July 2018
- Purity test date: no data

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: 15 - 25°C below 70% RH.
- Stability under test conditions: no data
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing:
- Preliminary purification step (if any):
- Final dilution of a dissolved solid, stock liquid or gel:
- Final preparation of a solid:

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Adult human-derived epidermal keratinocytes are seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen.

Justification for test system used:

The EPISKINTM(SM) model has been validated for corrosivity testing in an international trial (Fentem, 1998) and its use is recommended by the relevant OECD guideline for corrosivity testing (OECD No. 431); therefore, it was considered to be suitable for this study.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: Adult human derived epidermal keratinocytes
- Tissue batch number(s):
- Production date:
- Shipping date:
- Delivery date:
- Date of initiation of testing:

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

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps:
- Observable damage in the tissue due to washing:
- Modifications to validated SOP:

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration:
- Incubation time:
- Spectrophotometer:
- Wavelength:
- Filter:
- Filter bandwidth:
- Linear OD range of spectrophotometer:

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability:
- Barrier function:
- Morphology:
- Contamination:
- Reproducibility:

NUMBER OF REPLICATE TISSUES:

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues / killed tissues
- Procedure used to prepare the killed tissues (if applicable):
- N. of replicates :
- Method of calculation used:

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION:

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if [complete, e.g. 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 [complete, e.g. 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%.]
- Justification for the selection of the cut-off point(s) if different than recommended in TG 431 and 439:

Control samples:

yes, concurrent no treatment

Duration of treatment / exposure:

4 hours

Duration of post-treatment incubation (if applicable):

The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution.

Number of replicates:

6

Test system

Type of coverage:

occlusive

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: Optical density

Run / experiment:

Mean

Value:

0.727

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The results of this study indicate that chinomethionate is not corrosive to skin.