Bis(2,4,4-trimethylpentyl)phosphinic acid

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

Skin irritation/corrosion

A primary dermal irritation study is available. In this study performed similarly to the OECD guideline No. 404, 6 male New Zealand White rabbits, were dermally exposed to 0.5 ml of undiluted test substance.

Prior to the topical application, the skin of the rabbit was prepared with an electric clipper to remove the hair. After clipping, the left side of the animal was prepared by making epidermal abrasions, while the right site remained intact (clipped but unabraded). The test substance was then applied on the skin (abraded or not) on two different application sites (site 1 and 2). Then the test sites were covered with an occlusive dressing for 24 hours. Those exposure conditions correspond to a worst case approach as the test guidance recommends an exposure under semi-occlusive patch and for 4h. Skin irritation was assessed and scored according to the Draize scale at 24 and 72 hrs after the topical application of the test patch. The mean individual scores calculated within 2 scoring times (24 and 72 hrs) for the unabraded skin were 0.5/0.5/0.5/1.0/1.0/1.0 for erythema and 1.5/1.0/1.0/1.0/1.5/1.5 for edema. Therefore the registered substance is considered as slightly irritating to the rabbit skin.

Severe skin irritation was observed in one of the two acute dermal toxicity studies. However, worst case conditions were used such as an occlusive patch, a 24h exposure period and a large amount of test substance (approximately 10 times higher than the volume required in a specific skin irritation study (5 ml vs 0.5 ml). Such severe conditions could explain the observed skin irritation in the dermal acute toxicity tests.

Eye irritation

Two studies were available and both studies were of the same Klimisch validity, but the study considered as the key study in a worst case approach as the results of the study permit to classify the substance as irritating to eyes. In this study performed similarly to the OECD No. 405 guideline and in compliance with the GLP, 0.1 ml of undiluted test material was instilled into the conjunctival sac of left eye of male Albino New Zealand Rabbits. After the instillation the substance was not remained for 6 animals while for the three others the treated eye was washed with water 20 to 30 seconds after the instillation. Animals were then observed for 7 days for eye edema and erythema of the conjunctive, corneal opacity and iris lesion. Eye irritation was assessed and scored according to the Draize scale at 24, 48 and 72 hrs after the instillation of the substance and then at days 4 and 7. The mean individual score were calculated within 3 scoring times (24, 48 and 72 hrs).For the animals whose eye was not rinsed, the mean individual scores were 1.7/2.3/1.7/2.0/2.0/3.3 for chemosis, 1.3/2.0/1.7/1.7/1.0/2.0 for conjunctival erythema, and 0.7/0.7/0.7/0.7/1.7/2.0 for corneal opacity. All of these effects were not totally reversible within the termination of the study (7 days) in all animals. Indeed, cornea opacity was still observed by day 7 in 2 animals, redness and chemosis of the conjunctivae were still observed in 3 animals. However there is a tendency to reversibility. In addition, there was no effect on the iris of all unirrigated animals. For the animals, whose eye was washed after the instillation, slight and transient effects of the conjunctivae were observed within the first 3 days after the instillation.

Justification for classification or non-classification

Based on the available data (erythema and edema scores are lower than 2.3), the test substance is not classified for skin irritation according to the criteria indicated in the CLP Regulation (EC) No 1272/2008.

Based on the chemosis scores (≥2) obseved in 4 out of 6 animals in the key study, the substance is classified in Category 2 for Eye irritation (H319) according to the CLP Regulation (EC) No.1272/2008.