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Toxicological information

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
Study period:
Apr 8-9, 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The present study was performed within the framework of toxicity studies of chemicals required by regulatory authorities in accordance with the presently valid OECD Guideline 431 and the Council Regulation (EC) No. 440/2008 and was performed in compliance with the Good Laboratory Practice (GLP) regulations.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD Guideline 431
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test system

Type of coverage:
other: in vitro human skin model
Preparation of test site:
other: in vitro human skin model
Vehicle:
water
Amount / concentration applied:
For the test item 20 mg, for positive and negative controls 40 µL were dosed per tissue
Observation period:
3 min, 1 h
Details on study design:
Positive control: Potassium hydroxide (8N)
Negative control: Distilled water

Results and discussion

Any other information on results incl. tables

The results obtained after treatment with Phenolphthalein are given in the following table:

dose group treatment interval mean optical density mean relative viability [%]
neg. control 3 min 1.668 100.0
1 h 2.045 100.0
pos. control 3 min 0.310 18.60
1 h 0.374 18.30
Phenolphthalein 3 min 1.935 116.04
1 h 1.687 82.47


Treatment with the positive control induced a sufficient decrease in the relative absorbance as compared to the negative control for the treatment interval thus ensuring the validity of the test system.

After treatment with the negative control the absorbance values reached the required acceptability criterion of an OD >0.8 for the treatment interval thus showing the quality of the tissues.

The mean relative tissue viability after treatment with the test item was not significantly decreased after treatment. Therefore, the test item is not considered to possess a corrosive potential.

Applicant's summary and conclusion

Interpretation of results:
other: not corrosive
Conclusions:
Under the experimental conditions reported, phenolphthalein is not corrosive to skin.
Executive summary:
Purpose
The purpose of this assay was to identify potential of phenolphthalein for skin corrosion using an in vitro in vitro method as defined by the OECD Technical Guideline for Testing of Chemicals no 431.

Study Design
The test consisted of a topical exposure of the test item to a human reconstructed model followed by a cell viability test. Cell viability was measured by dehydrogenase conversion of MTT into a blue formazan salt, that was quantitatively measured after extraction from tissues. The percent reduction of cell viability in comparison to untreated negative controls was used to predict skin corrosion.
Triplicates of the human skin model RHE were treated either with the negative or the positive control for 3 minutes and 1 hour. 40 µL of the negative control (distilled water) or 40 µL of the positive control (potassium hydroxide, 8N) were applied to three tissues, respectively. For the test item, phenolphthalein, three tissue per time point (3 minutes and 1 hour) was used. 20 mg of the test item were applied to each tissue, spread to match the tissue size.


Results

Treatment with the positive control induced a sufficient decrease in the relative absorbance as compared to the negative control for the treatment interval thus ensuring the validity of the test system.
After treatment with the negative control the absorbance values reached the required acceptability criterion of an optical density (OD) >0.8 for the treatment interval thus showing the quality of the tissues.
The mean relative tissue viability after treatment with the test item (phenolphthalein) was not significantly decreased after treatment. Therefore, the test item is not considered to possess a corrosive potential.


Conclusion
Under the experimental conditions reported, phenolphthalein is not corrosive to skin.