(E)-2-((4-(ethyl(2-hydroxyethyl)amino)phenyl)diazenyl)-6-methoxy-3-methylbenzo[d]thiazol-3-ium trichlorozincate

Endpoint summary

Description of key information

Non-skin irritant

Eye irritant

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:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

The skin and eye irritation potential of the substance was evaluated from available data on Similar Substances, due to the absence of data on Target Substance. Justification for Read Across is given in Section 13 of IUCLID.

Skin irritation

The key study [Huntsman Textile Effects (Germany) GmbH, 1989] on Similar Substance 01 is performed according to the OECD Guideline 404. Three female New Zealand White rabbits were dermally exposed to 0.5 g of the test item on a moistened gauze patch to the shaved flank. Test sites were covered with a semi-occlusive dressing for 4hours. Animals were then observed for 72 hours. Irritation was scored by the method of Draize. The test material did not produce any signs of erythema or edema.

Available data on other similar substances (attached) support the non-irritation potential of the Similar Substance 01. These substances present a different salification from the Target substance and are therefore considered that their irritation potential is similar to the one of the Target substance. It is notable that only one animal presented a significant irreversible edema (edema score=2.33) on the abraded skin after a 24 hr exposure to the substance. The key study is considered to be the most representative for the substance since it is performed according to an OECD Guideline, the test material's purity is considerably high and its test conditions permit the evaluation of its classification (exposure period, assessment of reversibility, no of animals used). Chemosis and/or reddening of the conjunctivae, hyperemia of the scleral blood vessels and discharge were reversible by day 14 after administration. It is therefore concluded that the substance is not a skin irritant.

Eye irritation

The key study [Huntsman Textile Effects (Germany) GmbH, 1995] on Similar Substance 01 is performed according to the OECD Guideline 405.

0.1 g of the test substance was instilled into the conjunctival sac of the left eye of 3 young adult New Zealand White rabbits. The treated eyes were not rinsed after application. Scoring of irritation effects was performed approximately 1, 24, 48 and 72 hours, as well as 7 and 14 days after test article application. Irritation was scored by the method of Draize. The scores of each animal at 24, 48 and 72 hours were used for calculating the respective mean values for each type of lesion. The primary irritation score was calculated by totalling the individual cumulative scores at 24, 48, and 72 hours and then dividing the resulting total by the number of figures.

The mean (24/48/72) iris score for two animals was 0 and 0.33 for one, the mean cornea opacity score was 0 for two animals and 1 for one, the mean conjuctivae redness was 2 for two animals and 1.67 for one animal. The mean score for conjuctiave chemosis was 1.33 for all the three animals.

Based on the available data the substance is considered as an eye irritant.

Further data (attached) on other analogue substances (different salification) is available and were also taken into consideration for the evaluation of the irritation potential of the substance. Three studies concluded that the analogue substances are not irritant. Other studies showed that the substance could have corrosive properties, however, these studies were disregarded due to the presence of some impurities in the test material that render the test substance as corrosive. In these cases, the toxic effects observed could be not due to the substance itself but due to the impurities present. The study used as a key study is performed following the OECD Guideline and under GLP conditions and is considered as the most rapresentative for the evaluation of the eye irritation. The fact that the eyes of the animals were not rinsed after the application of the substance (solid powder) could have contributed to the effects observed, however, considering also all the other data and following a precautionaty approach, the substance is considered as an eye irritant.

Justification for classification or non-classification

The classification of the substance is based on data on Similar Substances. Justification for Read Across is given in section 13 of IUCLID.

Skin Irritation

The key study and other available studies suggest that the substance is not a skin irritant. The mean score (24/48/72h) of erythema and edema was not in the range of ≥ 2.3 - ≤ 4.0 therefore the substance is not classified for skin irritation according to the CLP Regulation (EC) No. 1272/2008.

Eye irritation

The key study and other available studies suggest that the substance is an eye irritant. The mean score (24/48/72h) of conjuctivae redness is equal to 2 for two out of three animals therefore the substance is classified in Category 2 for eye irritation (H319) according to the CLP Regulation (EC) No. 1272/2008.