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Toxicological information

Skin irritation / corrosion

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Administrative data

skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference Type:
study report
Report Date:

Materials and methods

Test guideline
according to
other: OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test) (2004)
GLP compliance:
yes (incl. certificate)

Test material


Test animals

other: Assessment of corrosive potential of the test substance by determination of its cytotoxic effect on an in vitro reconstructed human epidermis (exposure 3 min./rt and 60 min./37 °C, subsequently MTT).
Details on test animals and environmental conditions:
The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, St. Katharinen, Germany). Inserts were of 0.6 cm² size. The model has a functional stratum corneum with an underlying layer of living cells. The barrier function of the stratum corneum is adequate, as has been shown by the supplier.

Test system

unchanged (no vehicle)
other: as negative control: physiological saline solution (0.9 % NaCl, 50 µL)
Amount / concentration applied:
25 mg per insert
Duration of treatment / exposure:
3 min./room temperature or 60 min. in an incubator (37 °C, 5 % CO2, maximum humidity)
Observation period:
post-exposure incubation: none
Details on study design:
The corrosive potential of the test item is assessed by determination of its cytotoxic effect on an in vitro reconstructed human epidermis. The test principle is based on the MTT assay reflecting the cell viability after exposure of the epidermal equivalent to topically applied test item.
All tests were performed in triplets for each time point. The test item was applied at a 100 % concentration, i.e. 25 mg per insert (plus 50 µl 0.9 % NaCl-solution to moisten and ensure good contact to the tissue), for 3 min. (room temperature) or 60 min. (37 +/- 2 °C, 5 % CO2, maximum humidity). Cell viability was measured by the amount of MTT reduction, i.e. an OD value following exposure to the negative control substance or the test item.

Results and discussion

Any other information on results incl. tables

Substances are classified as „corrosive (R34)“, if the cell viability of the EST 1000 is decreased by more than 50 % after 3 min. of incubation to the test item, or if the cell viability is less than 15 % after 60 min. of exposure to the test item.

 Sample No.

 Test item

 Time [min.]

 % Viability

 1 -3

  control NaCl 0.9 %



 4 -6

test item



 13 -15

  control NaCl 0.9 %



 16 -18

  test item



The test item was characterized by no significant impact on cell viability after 3 min. or after the 60 min. period.

Applicant's summary and conclusion

Interpretation of results:
other: no corrosive property
Executive summary:

An in vitro study according to OECD TG 431, for predicting non specific, corrosive potential of substances was conducted. Undiluted test item was applied topically on a reconstructed human skin (25 mg per insert plus 50 µl saline solution to moisten and ensure good contact to the tissue; EST-1000, CellSystems, Germany). After an exposure period of 3 minutes at room temperature or 60 minutes in an incubator (37 °C, 5 % CO2, maximum humidity), the cell viability was 109 % and 87 %, respectively, as measured by a MTT conversion assay. It is therefore concluded that the test substance is not corrosive to the skin.