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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:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP compliant OECD guideline 439 study. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Version / remarks:
(2010)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
semi-solid (amorphous): gel
Remarks:
migrated information: paste

Test system

Details on study design:
An in-vitro study with the EpiDermTM human skin model comprising a reconstructed epidermis with a functional stratum corneum was performed. The EpiDermTM tissues were obtained by MatTek. The tissue was moistened with 25 µL DPBS (Dulbecco`s Phosphate Buffered Saline) to ensure good skin contact before 25 mg of the test substance were applied directly atop the EpiDermTM tissue. DPBS was used as negative control while 5% SDS (Sodium dodecyl sulfate) was used as positive control. A total of 3 tissues per dose group were used in duplicate. Irritation properties of the test substance are identified by the decrease of cell viability after exposure as determined by using the MTT reduction assay.
The tissues were maintained at 37 °C in humidified atmosphere (5% CO2/95% air). All media used during the study (for instance the incubation medium and MTT medium) were pre-warmed. After treatment, tissues were incubated at 37 °C in humidified atmosphere for 35 min and placed at room temperature thereafter. After 60 min the tissues were washed with DPBS, placed in pre-warmed incubation medium and were further incubated for 24 h at 37 °C in humidified atmosphere. After a medium change the tissues were incubated for additional 18 h prior to incubation in MTT medium for 3 h. After incubation in MTT the tissues were three times rinsed with DPBS before extraction of the reduced MTT with isopropanol for 2 hours. Per each tissue two aliquots of the extract were transferred into 96-well plates and analysed in a plate spectrophotometer.
The MTT reducing potential and the coloring potential of the test substance as possible confounding factors were assessed.
A test substance is concluded to be irritating if the relative mean tissue viability after 60 minute exposure and 42 hours post-treatment incubation is below 50%.

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
other:
Value:
6.8
Remarks on result:
other:
Remarks:
Basis: mean all tissued. Time point: 60 min. Max. score: 100.0. Reversibility: other: not applicable. Remarks: A test substance is considered to be irritating if the viability after 60 minutes is at or below 50%.. (migrated information)
Other effects / acceptance of results:
The test item showed irritating potential. However, only two experiments with test item treated tissues instead of three were evaluated due to loss of one tissue during washing. As each experiment was performed in duplicate 4 tissues were assessed. The test mets the acceptance criteria (for details see any other information on results).

Any other information on results incl. tables

Table 1: Summary of results

Test group

n

Treatment period (min)

Mean OD550value

Viability (%)

Mean inter tissue viability difference (%)

Negative control

3

60

1.78

100

15.8

Test item

2*

60

0.12

6.8

0.8

Positive control

3

60

0.12

6.6

0.9

* Only two test item treated tissues instead of three were evaluated due to loss of one tissue during washing.

The test meets acceptance criteria if:

Mean OD of the three negative control tissues is above≥ 1 and ≤2.5

Mean relative tissue viability of the three positive controls is at or below 20%,

The maximum inter tissue viability difference (determined as SD) between tissues treated identically is at or below 18%.

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant)
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: Skin irrit 2, H315
DSD: Xi, R38