1,3,5-Triazine-2,4,6-triamine, N2,N2'-1,6-hexanediylbis[N4,N6-dibutyl-N2,N4,N6-tris(2,2,6,6-tetramethyl-4-piperidinyl)-

Endpoint summary

Description of key information

The test article was not irritating to the skin when tested in vivo and in vitro. An in vitro eye irritation test battery found the test item to be irritating to the eye.

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

The potential of the test article to cause acute dermal irritation or corrosivity was assessed by a single topical application of an amount of 0.5 g of the test item for 4 hours to the intact skin of three New Zealand White rabbits (stepwise procedure starting with one animal and supplementing two additional animals), using a patch of 2.5 cm x 2.5 cm, covered with semi- occlusive dressing. After removal of the patch the application area was washed off. The cutaneous reactions were assessed immediately after removal of the patch, and approximately 1, 24, 48 and 72 hours after removal of the patch. In two out of three animals very slight erythema (grade 1) was noted either immediately after removal the patch or at hour 1 and persisted until hour 48. The cutaneous reactions were reversible in two animals within 72 hours after removal of the patch. The third animal did not show any local skin effects during the observation period. Mean scores over 24, 48 and 72 hours for each animal were 0.0, 0.7 and 0.7 for erythema and 0.0, 0.0 and 0.0 for edema. Considering the described cutaneous reactions as well as the average score for irritation, the test item does not show a skin irritating potential under the test conditions chosen.

This finding is supported by the findings of an in vitro dermal irritation test battery, which also showed a lack of dermal irritation potential for the test item.

Eye irritation

In order to assess the ocular irritation potential of the test item, an in vitro testing approach was performed. Using the currently available methods a single in vitro assay may not always be sufficient to cover the full range of eye irritating potential. Therefore, two in vitro assays were part of this in vitro eye irritation test strategy: The Bovine Corneal Opacity and Permeability Test (BCOP Test) and EpiOcular Eye Irritation Test.

In the BCOP assay, the potential of the test item 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 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; de-ionized water) and a positive control (PC; 20% imidazole in de-ionized water) were applied to three corneas each.

Corneal opacity was measured quantitatively as the amount of light transmitted through the cornea. Permeability was measured quantitatively 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.

In the EpiOcular assay, the potential of the test item to cause ocular irritation was assessed by a single topical application of 50 μL bulk volume (about 20 mg) of the undiluted test substance to a reconstructed three dimensional human cornea model (EpiOcular™).

Two EpiOcular™ tissue samples were incubated with the test substance for 6 hours followed by a 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 testsubstance treated epidermal tissues is compared to that of negative control tissues. The ratio of the values indicates the relative tissue viability.

Summary of the individual test results of the in vitro eye irritation turnkey testing strategy:

Test Method	Test Result	Test Evaluation	Evaluation Test Strategy
BCOP Test	The mean IVIS of the test-substance treated corneas was 135	ocular corrosive/ severe irritant	ocular corrosive/ severe irritant
EpiOcular	Mean viability of the test-substance treated tissues was 2%	Irritant

Based on the results for BCOP and EpiOcular Test the test article causes ocular corrosion or severe irritation in the in vitro eye irritation test strategy under the test conditions chosen.

Justification for classification or non-classification

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

The available experimental test data are reliable and suitable for the purpose of classification under Regulation (EC) No.1272/2008. Based on the data, the test item is considered severly irritating to the eye and classified with Eye Irritation Cat 1 under Regulation (EC) No.1272/2008.