1,3-Benzenediol, 4-butyl-

Skin irritation / corrosion

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Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No. 761/2009, Method B.46; 'In-vitro skin irritation : Reconstructed human epidermis model test' adopted 23 July 2009

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for the Testing of Chemicals, Draft Proposal for a New Guideline, In Vitro Skin Irritation : Reconstructed Human Epidermis (RhE) Test Method, Version 7.6, 9 September 2009

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: ECVAM international validation study on in vitro tests for acute skin irritation : Report on the validity of the EPISKIN and EpiDerm assays and on the Skin Integrity Function Test (Altern Lab Anim. 2007 Dec; 35 (6) : 559-601)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: Protocol for IN VITRO EpiDerm TM Skin Irritation Test (EPI-200-SIT), Rev. 3/23/2009, matTek Corporation, Ashland, MA 01721, USA

Deviations:

no

Test material

Test material information

Constituent 1

Test animals

Species:

other: In-vitro assessment using EpiDerm TM tissue

Strain:

other: In-vitro assessment using EpiDerm TM tissue

Test system

Type of coverage:

other: In-vitro assessment using EpiDerm TM tissue

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

other: other: Percentage value of formazan production in comparison to negative control

Value:

24.9

Remarks on result:

other:

Remarks:

Basis: other: Tissue 1. Time point: 60 minutes. (migrated information)

Results 2

Irritation / corrosion parameter:

other: other: Percentage value of formazan production in comparison to negative control

Value:

24.7

Remarks on result:

other:

Remarks:

Basis: other: Tissue 2. Time point: 60 minutes. (migrated information)

Results 3

Irritation / corrosion parameter:

other: other: Percentage value of formazan production in comparison to negative control

Value:

25.2

Remarks on result:

other:

Remarks:

Basis: other: Tissue 3. Time point: 60 minutes. (migrated information)

Any other information on results incl. tables

Findings and Results

Measured Values

As blank, the optical density of isopropanol was measured in eight wells of the 96 well plate. The measure values and their mean are given in the following table :

Replicate	Absorption
1	0.041
2	0.051
3	0.040
4	0.038
5	0.040
6	0.039
7	0.042
8	0.036
Mean	0.041

The absorption values of negative control, test item and positive control are given in the following table :

Designation	Measurement	Negative Control	4 -N-Butylresorcinol	Positive Control
Tissue 1	1	2.293	0.545	0.223
Tissue 1	2	2.273	0.538	0.225
Tissue 2	1	2.149	0.537	0.230
Tissue 2	2	1.986	0.536	0.235
Tissue 3	1	1.825	0.548	0.231
Tissue 3	2	1.776	0.548	0.235

From the measured absorptions, the mean of each tissue was calculated, subtracting the mean absorption of isopropanol. Mean and relative standard deviation (comparison of the three tissues) were also calculated.

Designation	Negative Control	4 -N-Butylresorcinol	Positive Control
Mean - blank (tissue 1)	2.242	0.501	0.183
Mean - blank (tissue 2)	2.027	0.496	0.192
Mean - blank (tissue 3)	1.760	0.507	0.192
Mean of the three tissues	2.010	0.501	0.189
Relative standard deviation of the three tissues	12.0%	1.1%	2.7%

Comparison of Formazan Production For the test item and the positive control, the following percentage values of formazan production were calculated in comparison to the negative control :

Designation	4 -N-butyl resorcinol	Positive Control
% Formazan production (tissue 1)	24.9%	9.1%
% Formazan production (tissue 2)	24.7%	9.6%
% Formazan production (tissue 3)	25.2%	9.6%
% Formazan production mean	24.9%	9.4%

Assessment and Validity. Irritation potential of the test item. The relative absorbance values were reduced to 24.9% after the treatment. This value is below the threshold for irritation (50%). Therefore, the test item is considered as irritant. Validity and acceptability. Validity criteria and results are stated in the following table :

Criterion	Demanded	Found
OD of negative control	between 1.0 and 2.5	2.010
% Formazan production of positive control	<=20% of negative control	9.4%
Variation within replicates (RSD)	<18%	12.0% (negative control)2.7% (positive control)1.1% (test item)

The value of the positive control was within the range of historical data.

The value for the negative control was not within the range of historical data of the test facility. This is considered as uncritical for the following reason : the deviation was only 0.6% above the respective range of the historical data. Variation of biological systems within this order of magnitude is not unusual ; furthermore, for the preparation of different batches of cell cultures, different cell donors may have been used. Therefore the experiment is considered valid.

The photometric absorption of the negative controls is considered as 100%. For the mean of the three replicates of the test item and positive control, formazan production is calculated as % photometric absorption compared with the negative control :

% Formazan production = [OD test item / OD negative control] x 100

Skin irritation potential of the test item is assessed as given in the following :

% Formazan production                                                 Assessment

<50% of negative control                                                 Irritant

>50% of negative control                                                 Non-irritant