dialuminium manganese tetraoxide, spinel type

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 Guideline for the Testing of Chemicals, Draft proposal for a New Guideline, In Vitro Skin Irritation: Human Skin Model Test, December 2007.

Deviations:

yes

Remarks:

In the first pre-test for colour formation, 1 mL H2O demin. was used instead of 0.3 mL H2O demin. This deviation was assessed as uncritical; no formation of colour was observed after the incubation time.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Ceramic materials and wares, chemicals

EC Number:

266-340-9

EC Name:

Ceramic materials and wares, chemicals

Cas Number:

66402-68-4

Molecular formula:

MnAl2O4

IUPAC Name:

dialuminium manganese tetraoxide, spinel type

Test animals

Species:

other: Human Skin

Strain:

other: not applicable

Test system

Type of coverage:

open

Preparation of test site:

other: not applicable

Vehicle:

unchanged (no vehicle)

Controls:

other: 3 tissues as positive, 3 tissues as negative control

Amount / concentration applied:

Tissue Amount
1 24.3 mg
2 24.9 mg
3 24.3 mg

Duration of treatment / exposure:

60 min

Observation period:

42 h

Number of animals:

3 tissues

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: %Formazan Production

Value:

88.5

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 42 hours. Max. score: 100.0. Reversibility: no data. (migrated information)

Any other information on results incl. tables

Evaluation

The values of the 96-plate-reader were transferred into a spreadsheet (Microsoft Excel®).

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

 Calculations

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

% Formazan production = (ODtest item/ODnegative control) * 100

Assessment

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

Assessment of Irritation Potential

% Formazan production	Assessment
< 50% of negative control	Irritant
> 50% of negative control	Non-irritant

Findings and Results

Measured Values

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

Absorption values negative control, test item and positive control (OD at 570 nm)    

Designation	Negative Control			Positive Control			Galaxite
Replicate	1	2	3	1	2	3	1	2	3
Absorption 1	2.355	1.855	1.926	0.199	0.208	0.223	1.724	1.777	1.940
Absorption 2	2.344	1.818	1.928	0.201	0.206	0.189	1.709	1.784	1.911
Following calculation of the mean, the mean absorption value of isopropanol was subtracted.
Absorption Mean - Blank	2.307	1.794	1.884	0.157	0.164	0.163	1.674	1.738	1.883
Absorption Total Mean	1.995			0.161			1.765
Absorption RSD	13.7 %			2.4%			6.1%

Comparison of Formazan Production

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

% Formazan Production

Test Item	Positive Control
88.5%	8.1%

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 88.5%. 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 88.5%. 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.