Disodium 2-[4-[[1-[[(2-methoxy-5-methyl-4-sulphonatophenyl)amino]carbonyl]-2-oxopropyl]azo]phenyl]-6-methylbenzothiazole-7-sulphonate

Endpoint summary

Description of key information

Skin irritation

The test substance does not show a skin irritation potential in the EpiDerm™ in vitro skin irritation and corrosion test strategy under the test conditions chosen.

Eye irritation

Based on the observed results for the EpiOcular Test alone and applying the evaluation criteria it was concluded, that the test substance does not show an eye irritation potential in the in vitro eye irritation test strategy under the test conditions chosen.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation study - in vitro

The test substance was tested in vitro in line with GLP for skin corrosion according OECD 431 and EU guideline B.40 and for skin irritation according OECD 439and EU guideline B.46.

However, in the current case the results derived with Skin Irritation Test (SIT) alone were sufficient for a final assessment. Therefore further testing in Skin Corrosion Test (SCT) SCT was waived.

 

The potential of the test substance to cause dermal corrosion/irritation was assessed by a single topical application of ca. 25 μL bulk volume (ca. 26 mg) of the undiluted test substance to a reconstructed three dimensional human epidermis model (EpiDerm™).

The irritation test was performed with three EpiDerm™ tissues, which were incubated with the test substance for 1 hour followed by a 42-hours post-incubation period.

Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test-substance treated epidermal tissues is compared to that of negative control tissues. The quotient of the values indicates the relative tissue viability.

The following results were obtained in the EpiDerm™ skin irritation test:

The test substance is not able to reduce MTT.

The mean viability of the test-substance treated tissues determined after an exposure period of 1 hour with about 42 hours post-incubation was 104.5%.

The test-substance treated tissues showed a slightly yellow discoloration after the washing procedure. However, this did not interfere with the colorimetric test as was demonstrated in a pretest prior to start of the GLP study.

The inter-tissue variability of the test-substance treated tissues (SD of %-viability) is minimally out of the acceptance range. Since the single viability values are well above the cut off for skin irritation and all other quality criteria of the test were met, this deviation is not considered to adversely affect the result of this study.

Based on the observed results and applying the evaluation criteria it was concluded, that the test substance does not show a skin irritation potential in the EpiDerm™ in vitro skin irritation and corrosion test strategy under the test conditions chosen.

Eye irritation study - in vitro

In the GLP and OECD 437 guideline compliant study the test substance was assessed for eye irritating potential with an EpiOcular Eye Irritation Test.

The potential of the test substance to cause ocular irritation was assessed by a single topical application of ca. 50 μL bulk volume (ca. 36 mg) of the undiluted test substance to a reconstructed three dimensional human cornea model (EpiOcular™).

Two EpiOcular™ tissues were incubated with the test substance for 6 hours followed by an 18-hours post-incubation period.

Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test-substance treated epidermal tissues is compared to that of negative control tissues. The ratio of the values indicates the relative tissue viability.

The following results were obtained in the EpiOcular™ eye irritation assay:

The test substance is not able to reduce MTT directly.

The mean viability of the test-substance treated tissues was 67.7%.

The test-substance treated tissues showed a yellow discoloration after the washing procedure. However, this did not interfere with the colorimetric test as was demonstrated in a pretest prior to start of the GLP study.

Based on the observed results for the EpiOcular Test alone and applying the evaluation criteria it was concluded, that the test substance does not show an eye irritation potential in the in vitro eye irritation test strategy under the test conditions chosen.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008 (CLP). As a result the test substance is not considered to be classified for skin irritation and eye irritation under Regulation (EC) No 1272/2008, as amended for the tenth time in Regulation (EU) No 2017/776