Calcium disulphamate

Endpoint summary

Description of key information

Results from in vitro skin irritation test (Reconstructed Human Epidermis Test according to OECD TG 439): Mean tissue viability after an exposure period of 1 hour with an about 42-hour post-incubation was 95.3% --> not irritating.

Results from in vitro eye irritation test (OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage) -->

mean viability of the tissues treated with the test substance 5.1% --> irritating to eyes.

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)

Additional information

Skin irritation:

The skin irritation and corrosion potential of Calcium disulphamate was assessed in an in vitro skin irritation and corrosion test strategy: The Skin Corrosion Test (SCT) and Skin Irritation Test (SIT).

However, in the current case for Calcium disulphamate the results derived with SIT alone were sufficient for a final assessment. Therefore, further testing in SCT was waived. The potential of the test substance to cause dermal irritation was assessed by a single topical application of ca. 25 μL bulk volume (about 8 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-hour post-incubation period. Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation by 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 directly reduce MTT.

The final mean viability of the tissues treated with the test substance determined after an exposure period of 1 hour with an about 42-hour post-incubation was 95.3%.

Based on the results observed it was concluded that Calcium disulphamate 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:

The potential of Calcium disulphamate to cause ocular irritation was assessed by a single topical application of ca. 50 μL bulk volume (about 12 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 -hour post-incubation period.

Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post-incubation by 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 epidermal tissues treated with the test substance 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 directly reduce MTT.

The final mean viability of the tissues treated with the test substance was 5.1%.

Based on these results, the substance was concluded to show an eye irritation potential.

The potential of the test substance to cause ocular irritation or serious damage to the eyes was assessed by a single topical application of 750 μL of a 20% test-substance preparation in deionized water to the epithelial surface of isolated bovine corneas. Three corneas were treated with the test substance preparation for an exposure period of 4 hours.

In addition to the test substance, a negative control (NC; deionized water) and a positive control (PC; 20% imidazole in deionized water) were applied to three corneas each. Corneal opacity was quantitatively measured as the amount of light transmitted through the cornea. Permeability was quantitatively measured as the amount of sodium fluorescein dye

that passes across the full thickness of the cornea. Both measurements were used to calculate an In Vitro Irritancy Score of the test substance. The mean IVIS for the test substance, the negative and the positive control was 0.1, 14.1, and 160.3, respectively. The substance was therefore not identified as corrosive or severe irritant.

Justification for classification or non-classification

The results from skin irritation and eye irritation studies were evaluated according to the Classification, Labelling and Packaging Regulation (CLP).

Skin irritation: The test item does not meet the criteria for classification according to CLP.

Eye irritation: The test item is classified into Category 2 (irritating to eyes) based on CLP criteria.