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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation / corrosion
Remarks:
other: in vitro
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012-02-13 to 2012-02-17
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study.

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:
other: EU Method b.46 (Skin Irritation)
Deviations:
no
Qualifier:
according to
Guideline:
other: OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, München, Germany

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Name: Sodium methyl-4-hydroxybenzoate
CAS No.: 5026-62-0
Chemical Name: sodium 4-(methoxycarbonyl)phenolate
Physical State/Colour: solid/white
Storage Conditions: room temperature

Test animals

Species:
human
Strain:
other: EpiDerm reconstructed human epidermis model (MatTek Corp.)
Details on test animals and environmental conditions:
organotypic reconstructed three-dimensional model of the human epidermis

Test system

Type of coverage:
other: in vitro system; direct application
Preparation of test site:
other: intact reconstructed human epidermis
Vehicle:
other: DPBS (Dulbecco's Phosphate Buffered Saline)
Controls:
other: Concurrent control tissues treated with the vehicle served as negative controls, positive controls were exposed to 5% SDS.
Amount / concentration applied:
25 mg test substance in 25 µL DPBS
Duration of treatment / exposure:
60 ± 1 min
Observation period:
Not applicable. Post-treatment incubation period: 42 ± 4 h
Number of animals:
Not applicable. The test was performed in triplicates for each treatment and control group.
Details on study design:
3 replicate tissues are dosed with the test item, the negative control (DPBS) and the positive control (5% SDS), respectively. The tissues are incubated for 35 ± 1 minutes in a humidified incubator (37 ± 1 °C, 5 ± 1% CO2, 95% RH) and further 25 minutes at room temperature. Then the test item and the controls are rinsed off with DPBS and the tissues are post-incubated for 24 ± 2 h and, after medium renewal, for further 18 ± 2 h. Then the tissues are stained via MTT for 3 hours. Isopropanol extracts are measured photometrically at 550 nm.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
other: cell viability (%)
Basis:
other: mean value of negative controls (DPBS)
Time point:
other: 60 min
Score:
100
Reversibility:
other: not applicable
Irritation parameter:
other: cell viability (% of negative control)
Basis:
other: mean value of positive controls (5% SDS)
Time point:
other: 60 min
Score:
2.2
Reversibility:
other: not applicable
Irritation parameter:
other: cell viability (% of negative control)
Basis:
other: mean value of test substance
Time point:
other: 60 min
Score:
6.2
Reversibility:
other: not applicable
Other effects:
The test item showed no direct MTT reducing capability and no colouring potential.

Any other information on results incl. tables

Name

Negative Control

Positive Control

Test Item

Tissue

1

2

3

1

2

3

1

2

3

corrected OD550

2.171

2.167

2.186

0.052

0.048

0.044

0.094

0.172

0.132

2.111

2.203

2.114

0.050

0.046

0.048

0.099

0.176

0.134

mean corrected OD550
of the duplicates

2.141

2.185

2.150

0.051

0.047

0.046

0.097

0.174

0.133

mean corrected OD550
of 3 replicate tissues

2.159*

0.048

0.134

mean SD OD550

0.038

0.003

0.035

tissue viability [%]

99.2

101.2

99.6

2.4

2.2

2.1

4.5

8.1

6.2

SD tissue viability [%]***

1.1

0.1

1.8

CV [% viability]

1.1

5.5

28.7

mean tissue viability [%]

100.0

2.2**

6.2

*       Corrected mean OD550 of the negative control corresponds to 100% absolute tissue viability.

**      mean relative tissue viability of the three positive control tissues is  20%

***    standard deviation (SD) obtained from the three concurrently tested tissues is < 18%

Applicant's summary and conclusion

Interpretation of results:
irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
CLP: Skin Irrit. 2, H315
DSD: Xi, R38