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Administrative data

skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
13 june 2017 to 20 July 2017
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
The In vitro Skin Corrosion: Human Skin Model Test is based on the observation that skin corrosion (necrotic damage of viable skin cells) shows a high correlation with skin cell cytotoxicity, occurring rapidly after brief exposure of the skin barrier (stratum corneum) to a corrosive chemical. It is designed to predict and classify the skin corrosivity potential of a chemical by using a three-dimensional human epidermis model. The epidermis model (e.g. EpiDermTM) is derived from human keratinocytes and consists of normal, human-derived epidermal keratinocytes (NHEK) which have been cultured to form a multilayered, highly differentiated model of the human epidermis. The NHEK, which are cultured on specially prepared cell culture inserts using serum free medium, attain levels of differentiation at the cutting edge of in vitro skin technology. Ultrastructurally, the skin models closely parallel human skin. The In vitro Skin Corrosion: Human Skin Model Test consists of topical application of the test material to the tissue for 3 minutes and 1 hour, followed by immediate determination of the cytotoxic effect. Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the exposure period.

Data source

Reference Type:
study report
Report Date:

Materials and methods

Test guideline
according to
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
GLP compliance:
yes (incl. certificate)

Test material

Test material form:
solid: crystalline
Details on test material:
White powder
Specific details on test material used for the study:
Batch: 18128093
Purity: 100.5%

In vitro test system

Test system:
human skin model
Source species:
Cell type:
non-transformed keratinocytes
Cell source:
foreskin from multiple donors
Amount/concentration applied:
25 ± 2 mg (39.7 mg/cm2 according to guideline) of the test item were applied onto the surface of duplicate EpiDermTM tissue. The test item was wetted with 25 μL of deionised water.
Duration of treatment / exposure:
Duplicate EpiDermTM tissues were treated with the test item, positive control or negative
control for the following exposure times:
• Test Item: 3 ± 0.5 minutes, 60 ± 5 minutes
• Negative Control: 3 ± 0.5 minutes, 60 ± 5 minutes
• Positive Control: 3 ± 0.5 minutes, 60 ± 5 minutes

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
other: Relative absorbance
Run / experiment:
3 min
Vehicle controls validity:
Negative controls validity:
Positive controls validity:
Irritation / corrosion parameter:
other: Relative absorbance
Run / experiment:
60 min
Vehicle controls validity:
Negative controls validity:
Positive controls validity:

Any other information on results incl. tables

This in vitro study was performed to assess the corrosive potential of CARBANINE CRIST by means of the Human Skin Model Test with EpiDerm™ tissues models.

The test item passed the MTT- and the colour interference pre-tests.

Independent duplicate tissues of EpiDermTM were exposed to the test item, the negative control (deionised water) or the positive control (8.0 N KOH) for 3 minutes and 1 hour, respectively.

Afterwards, the test and the control items were rinsed off the tissues, and a 3 hour incubation period (37 ± 1 °C, 5 ± 0.5 % CO2) with MTT solution followed. MTT solution was then rinsed from the wells and the wells were rinsed with DPBS. Inserts were transferred into new 24 well plates. The formazan salt was extracted for about 19.5 hours at room temperature.

The required acceptability criteria were met.

Exposure to the positive control induced a decrease in the relative absorbance as compared to the negative control, both for the 3 minutes exposure period (21.4%) and for the 1 hour exposure period 4.8%) thus confirming the validity of the test system and the specific batch of tissue models.

After 3 minutes exposure to the test item CARBANINE CRIST the relative absorbance value was not reduced (103.2%). After 1 hour exposure the relative absorbance value decreased to 88.8%. Both values did not exceed the threshold for corrosivity which is defined to be 50% after the 3 minutes exposure and 15% after the 1 hour exposure. Therefore, the test item is not considered to be corrosive.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
In conclusion, it can be stated that in this study and under the reported experimental conditions, CARBANINE CRIST is non corrosive to skin according to EU CLP and UN GHS.