O-ethylhydroxylamine

Endpoint summary

Description of key information

- Skin: not irritating (comparable to OECD guideline 404)
- Eye: irritating (comparable to OECD guideline 405)

Additional information

Skin Irritation (in vivo)

The key study for skin irritation was performed using a protocol equivalent and similar to OECD TG 404. In a primary dermal irritation study 6 New Zealand White Albino Rabbits weighing 2669 - 3245 g were dermally exposed to 0.5 ml of 50% aqueous solution of Substance H109360 (approx. 46.4% ethoxyamine and approx. 5% ethanol) for 4 hours. The test substance was applied to shaved intact skin under occlusive conditions. Before scoring, the incubation site was washed with water. Skin irritation was scored 30 minutes, 1, 2, 3 and 4 days after termination of exposure using the Draize scoring system. Adjacent areas of the untreated skin of each animal served as controls. Marked systemic toxicity prevented a full assessment of irritation potential. One animal was found dead and 3 others had to be killed in extremis one day after end of exposure. However, signs of no more than slight irritation were observed on the two remaining surviving animals following the single 4- hour application of the test substance on the skin. The signs of toxicity obsereved were cyanosis, decreased breathing rate and decreased activity (Central Toxicology Laboratories, 1987)

Eye Irritation

In a study performed using a protocol equivalent and similar to OECD TG 405, 0.1 ml of 50% aqueous solution of Substance H109360 (approx. 46.4% ethoxyamine and approx. 5% ethanol) was applied to the conjunctival sac of the eye of 6 New Zealand White Rabbits (2669 -3245 g). The other eye remained untreated and served as control. The eyes of 3 animals were flushed 30 -36 seconds post instillation while the eyes of the remaining 3 animals were unwashed. Observation and scoring of the effects to the eyes were performed approximately 1 hour, 1, 2, 3, 4 days, 6 days (only 3 animals) and 7 days (only 4 animals) after instillation using the Draize scoring system. No significant effect was observed for the parameters corneal opacity (mean score: 0.77 (washed); 0.66 (unwashed)), Iritis (mean score: 0.44 (washed and unwashed), Redness (mean score: 1.33 (washed); 0.89 (unwashed) and Chemosis (mean score: 1.1 (washed); 0.73 unwashed). These effects were all reversible within 7 days (Central Toxicology Laboratories, 1987)

Justification for classification or non-classification

Skin Irritation

Classification for skin irritation is not warranted according to the criteria of EU Directive 67/548/EEC and EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Eye Irritation:

The results of the studies carried out with a 50% aqueous solution of Substance H109360 (approx. 45% ethoxyamine and 5% ethanol) indicate that the criteria for classification according to Directive 67/548/EEC and Directive 1272/ 2008 EC are not met. However, in view of the observed responses, the possibility that the concentration of 100% may be potentially irritating to to the eye cannot be ruled out. For the sake of prudence, it is therefore proposed to maintain the current classification for ethoxyamine according to Annex I of Directive No. 67/548/EEC as "Irritating to eyes" (R36) and according to Annex VI of Directive No. 1272/2008 /EC as "causes serious eye irritation" (Cat 2)