Dodecaaluminium calcium nonadecaoxide

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-07-14 - 2009-09-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD , Draft Proposal for a New Guideline, In Vitro Skin Irritation: Human Skin Model Test, 12/2007

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dodecaaluminium calcium nonadecaoxide

EC Number:

234-468-4

EC Name:

Dodecaaluminium calcium nonadecaoxide

Cas Number:

12005-50-4

Molecular formula:

Al12O19.Ca

IUPAC Name:

dodecaaluminium(3+) calcium nonadecaoxidandiide

Test system

Type of coverage:

open

Preparation of test site:

not specified

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

Tissue 1: 24.4 mg
Tissue 2: 24.5 mg
Tissue 3: 24.8 mg

Duration of treatment / exposure:

60 min

Number of animals:

3 tissues

Details on study design:

PURPOSE OF THE STUDY
This in-vitro study was performed in order to evaluate the potential of Dodecaaluminium calcium nonadecaoxide, Al12O19Ca (Calciumhexaluminate, CA6) to evoke skin irritation in a human-skin-model.
The test consists of a topical exposure of the neat test item to a human reconstructed epidermis model followed by a cell viability test. Cell viability is measured by dehydrogenase conversion of MTT [(3-4,5-dimethyl thiazole 2-yl) 2,5-diphenyl-tetrazoliumbromide], present in cell mitochondria, into a blue formazan salt that is quantitatively measured after extraction from tissues. The percent reduction of cell viability in comparison of untreated negative controls is used to predict skin irritation potential.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: mean formazan production

Value:

94.6

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 60 min. Reversibility: no data. (migrated information)

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item is considered not irritant.
After the treatment, the relative absorbance values were decreased to 94.6%. This value is well above the threshold for irritation (50%).
The optical density of the negative control was well within the required acceptability criterion of 1.0 < mean OD < 2.5. The positive control induced a decrease in the relative absorbance as compared to the negative control to 8.1 % (required:  20%) for thus ensuring the validity of the test system. Variation within replicates was within the accepted range for negative control, positive control and test item.
For these reasons, the result of the test is considered valid.

Executive summary:

The test item is considered not irritant.

After the treatment, the relative absorbance values were decreased to 94.6%. This value is well above the threshold for irritation (50%).

The optical density of the negative control was well within the required acceptability criterion of 1.0 < mean OD < 2.5. The positive control induced a decrease in the relative absorbance as compared to the negative control to 8.1 % (required:£20%) for thus ensuring the validity of the test system. Variation within replicates was within the accepted range for negative control, positive control and test item.

For these reasons, the result of the test is considered valid.