4-bromobenzyl alcohol

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

from 2017-11-21 to 2017-12-19

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:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: INVITTOX Protocol SkinEthic™ Skin Corrosivity Test

Version / remarks:

2012

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

4-bromobenzyl alcohol

EC Number:

212-851-7

EC Name:

4-bromobenzyl alcohol

Cas Number:

873-75-6

Molecular formula:

C7H7BrO

IUPAC Name:

(4-bromophenyl)methanol

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

The reconstructed human epidermis model in vitro method is an accepted in vitro method to replace animal testing. The human skin RHE™ model closely mimics the biochemical and physiological properties of the upper parts of the human skin, i.e the epidermis.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: SkinEthic™ RHE-model RHE/S/17
- Tissue batch number: 17-RHE-118
- Date of initiation of testing: 2017-11-21

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: Room temperature

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: rinsing with a minimum volume of 20 mL DPBS using a pipette
- Observable damage in the tissue due to washing: No
- Modifications to validated SOP: No

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h ± 15 min
- Spectrophotometer: microplate reader (ELx800, BioTek Instruments GmbH, Bad Friedrichshall, Germany)
- Wavelength: 570 nm
- Filter: filter test plate

NUMBER OF REPLICATE TISSUES: 2

NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 1

PREDICTION MODEL / DECISION CRITERIA
- 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 applied: 20 ± 3 mg per tissue

NEGATIVE CONTROL
- Amount applied: 40 ± 3 µL per tissue


POSITIVE CONTROL
- Amount applied: 40 ± 3 µL per tissue
- Concentration: 8N

Duration of treatment / exposure:

3 min or 1 h

Number of replicates:

2

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min

Value:

104.7

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 h

Value:

87.7

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

- OTHER EFFECTS:
- Visible damage on test system: No
- Direct-MTT reduction: No
- Colour interference with MTT: No

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: Yes
- Acceptance criteria met for positive control: Yes
- Acceptance criteria met for variability between replicate measurements: Yes

Any other information on results incl. tables

Table 1: Summary of the results

Group		Tissue 1		Tissue 2		Mean		CV
		OD	Viability	OD	Viability	OD	Viability	Viability
Negative Control	3 min	1.849	98.4%	1.908	101.5%	1.879	100.0%	2.2%
	1 hour	1.820	99.7%	1.832	100.3%	1.826	100.0%	0.4%
Positive Control	1 hour	0.008	0.4%	0.011	0.6%	0.010	0.5%	20.0%
Test Item	3 min	1.884	100.3%	2.048	109.0%	1.966	104.7%	5.9%
	1 hour	1.550	84.9%	1.651	90.4%	1.601	87.7%	4.4%

Applicant's summary and conclusion

Interpretation of results:

other: Not category 1 (corrosive) based on GHS criteria

Conclusions:

In an in vitro skin corrosion test (reconstructed human epidermis model, RHE), a cell viability of 104.7 % after 3 min incubation and 87.7 % after 1 h incubation was determined. According to the evaluation criteria, the test substance did not show skin corrosive properties.

Executive summary:

The corrosive potential of the test item was determined in a skin corrosion assay (RhE) according to OECD Guideline 431. The test item was applied topically to a human reconstructed skin model followed by determination of the cell viability. Cell viability was determined by enzymatic conversion of vital dye MTT into a blue formazan salt and measurement of the formazan salt after extraction from tissues. The percent reduction of cell viability in comparison to untreated negative controls was used to predict the skin corrosion potential. Duplicates of the human skin RHE-model were treated with the test item or the negative control for 3 minutes and additional 1 hour. Duplicates with the positive control were only treated for 1 hour. 40 ± 3 µL of either the negative control (deionised water) or the positive control (potassium hydroxide, 8N) were applied to the tissues. Before application of 20 ± 3 mg of the solid test item, 20 ± 2 µL of deionised water was spread to the epidermis surface to improve the contact between the test item and the epidermis. Positive and negative controls were valid. Following treatment with the test item the tissue viability was >50 % after 3 minutes exposure (mean viability: 104.7 %) and >15 % after 1 hour exposure (mean viability: 87.7 %). Thus, the test item is not considered as corrosive to skin.