Registration Dossier

Administrative data

Description of key information

The dermal and ocular irritant potential of Sodium hypophosphite was assessed using:
- an in vivo dermal irritation test in rabbits ( performed according to 49 CFR Part 173.240 method from the US Hazardous Materials Regulations. This method was comparable to the OECD 404 guideline issued in 1981. The study predates GLP requirements).
- an in vivo eye irritation test in rabbits (method comparable to EPA 870.2400 and OECD 405 guidelines, GLP compliance not stated in the study
report).
Based on these studies, Sodium hypophosphite is considered to be non-irritant for skin an 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/corrosion:

One valid study is recorded for this endpoint and was chosen as key study (Wilson, 1977).

The potential of sodium hypophosphite to induce skin irritation or corrosion was assessed in rabbits using the 49 CFR Part 173.240 method from the US Hazardous Materials Regulations. This method was comparable to the OECD 404 guideline issued in 1981. The study was performed before the implementation of GLP.

Six rabbits were dermally exposed to 500 mg of sodium hypophosphite for 4 hours. 3 received the test item onto an intact skin while the remaining received the test item onto an abraded area. The test substance was held in contact with the skin by means of an occlusive dressing. Cutaneous reactions were observed 24, 48 and 72 hours after removal of the dressing. No observation and no scoring were performed after 72 hours.

A slight erythema (scoring value 1) was observed in all animals at the 24 -hour reading and was still persistent in 1out 3 animals treated onto an intact skin and 2 out 3 animals treated on an abraded area at the 72 -hour reading. Only one animal with intact skin showed a slight oedema (scoring value 1) at the 72 -hour reading.

Based on these results and according to the criteria laid down in EC regulation 1272/2008/EC and EU directive 67/548/EEC, Sodium hypophosphite is considered as non-irritant to the skin and is not classified.

Eye irritation:

One study is recorded for this endpoint and was chosen as a key study.

The potential of Sodium hypophosphite to induce eye irritation was assessed in 9 rabbits according to methods similar to OPPTS 870.2400 and OECD 405 guidelines. There were no information in the report about GLP compliance.

A single dose of 100 mg of the test item was instilled into one eye, the other eye was not treated and served as control. For 6 rabbits, the eyes were not rinsed after administration of the test item while a washing procedure was applied for 3 other animals .Ocular reactions were observed 24, 48 and 72 hours after the administration and then daily until reversibility of the ocular reactions. The values of the scores for chemosis, redness of the conjunctiva, iris lesions and corneal opacity were noted for each animal.

Mean scores calculated over 24, 48 and 72 hours for the 6 animals without rinsing were 0.33 for chemosis, 0.89 for redness of the conjunctiva, 0 for iris lesions and 0 for corneal opacity. Redness and chemosis were fully reversible within 10 and 3 days respectively.

Washing procedure did not change the ocular reactions.

Based on these results and according to the criteria laid down in EC regulation 1272/2008/EC and EU directive 67/548/EEC, Sodium hypophosphite is considered as non-irritant when administered by ocular route and is not classified.

Justification for classification or non-classification

According to the criteria laid down in EU regulation (EC) n°1272/2008 (CLP) and EU Directive 67/548/EEC, sodium hypophosphite is neither classified for skin irritation/corrosion nor eye irritation.