4-Butoxy-2,3-difluor-4'-methyl-1,1'-biphenyl

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

March 6, 2017 - May 22, 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

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

Commission Regulation (EU) No. 640/2012 amending, for the purpose of its adaption to technical progress, Regulations (EC) No. 440/2008 laying down test methods pursuant to Regulation (EC) No. 1907/2006 of the European Parliament and the council on the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH).

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

July 28, 2015

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: Skinethic skin irritation test -42bis Standard operating procedure (SOP) 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-Butoxy-2,3-difluor-4'-methyl-1,1'-biphenyl

EC Number:

938-422-0

Cas Number:

1443311-78-1

Molecular formula:

C17H18F2O

IUPAC Name:

4-Butoxy-2,3-difluor-4'-methyl-1,1'-biphenyl

Test material form:

solid

Specific details on test material used for the study:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
No pre-treatment ;The test item was applied neat to the tissues.

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

foreskin from a single donor

Justification for test system used:

standard model

Vehicle:

unchanged (no vehicle)

Remarks:

No vehicle used in this study; The test item was applied neat to the tissues.

Details on test system:

CELL CULTURE
- Supplier: EpiSkin/SkinEthic Laboratories, Lyon, France)
- Source: human keratinocytes cultured on a polycarbonate filter in conditions which permit their terminal differentiation
- Format: 24 well plate
- Batch: 17-RHE-038
- Expires: April 3, 2017

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment: room temperature
- Temperature of post-treatment incubation: 37°C

REMOVAL OF THE TEST MATERIAL AND CONTROL
After the end of the treatment interval, the residual test item was removed immediately by gently rinsing with a minimum volume of 25 mL DPBS using a pipette. Excess DPBS was removed by gently shaking the inserts and blotting the bottom with blotting paper.

DYE BINDING METHOD
- Dye used in the dye-binding assay: MTT
- Spectrophotometer:ELx800, BioTek Instruments GmbH, Bad Friedrichshall, Germany at 570 nm

Control samples:

yes, concurrent negative control

Amount/concentration applied:

TEST MATERIAL: 16 mg of solid test material
NEGATIVE CONTROL: 16 µL (Dulbecco`s Phosphate-Buffered Saline)
POSITIVE CONTROL: 16 µL (5% aqueous solution of sodium dodecyl sulfate in deionised water)

Duration of treatment / exposure:

42 min (± 1 minute)

Duration of post-treatment incubation (if applicable):

42 hours (± 1 hour)

Number of replicates:

3

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Experiment 1 / Run 1

Value:

96.2

Vehicle controls validity:

not applicable

Remarks:

The test item was applied neat to the tissues

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system: none
- Direct-MTT reduction: none
- Colour interference with MTT: none

ACCEPTANCE OF RESULTS:

Acceptability of the Quality Control Data of the Skin Model with Reference to Historical Batch Data:
The negative control OD values were 1.906, 1.663 and 1.766 and, thus, in the range of ≥0.8 and ≤3.0.

Acceptability of the Positive and Negative Control Data:
After treatment with the positive control (5% aqueous solution of sodium dodecyl sulfate) the mean viability value was 1.4% (standard deviation: 21.4%) and, thus, lower than the historically established threshold of 3.03%.
After treatment with the negative control (DPBS-buffer) the mean OD was 1.778 (standard deviation: 6.9%) and, thus, higher than the historically established threshold of 1.459.
Variability of the Data:

The standard deviation between the three tissues replicates treated with the test item was 9.9% and, thus, ≤18%. The standard deviation between the three tissue replicates of the negative control was 6.9%.
The standard deviation between the three tissues replicates treated with the positive control was 21.4% and, thus, >18%. Due to the very irritant potential of the positive control very low viabilities were obtained. Little differences between very low viabilities resulted in a high standard deviation >18%. However, this does not influence the outcome or validity of the study.


The study met all acceptance criteria.

Any other information on results incl. tables

Group	Time / [min]	Mean OD	Mean Relative viability / [%]
Negative Control	42	1.778	100
Positive Control	42	0.025	1.4
Test Material	42	1.710	96.2

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Remarks:

UN GHS: No Caterory (according to OECD TG 439)

Conclusions:

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 439. Under the conditions of the present study, the test item is not considered to possess an irritant potential to skin (UN GHS: No Category).

Executive summary:

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 439. Under the conditions of the present study, the test item is not considered to possess an irritant potential to skin (UN GHS: No Category).