Phosphorus

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Similar to Buehler test red phosphorus was applied topically 10 times to the skin of guinea pigs at a concentration of 10% (w/w). 15 days after the last application the challenge was conducted and the skin scored according to the Draize scale:

The skin and surrounding hair were stained the same red shade as red phosphorus which was not the same colour as erythema.There was no response to the challenge dose of red phosphorus.

Migrated from Short description of key information:
Red Phosphorus was tested for sensitizing properties in guinea pigs similar to the Bühler method. The test substance did not show any sensitizing potential.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

There are no respiratory sensitization properties of the substance known in literature. Beyond this there is no hint of any sensitization property of the compound from the available skin sensitization study. Therefore, it is concluded that the subsance is not a respiratory sensitizer.

Migrated from Short description of key information:
Based on the existing data it is concluded that the substance is not a respiratory sensitizer.

Justification for classification or non-classification

Red Phosphorus has been tested in a skin sensitization study similar to the Bühler method to assess the sensitizing potential of the test item. In this test Red Phosphorus did not induce allergic reactions and therefore did not reveal any allergic response. Though the described study has some restrictions in reporting, sufficient detail is available to be able to judge it as reliable for this endpoint.

 

Furthermore, the substance is considered to have no sensitizing potential for the following reasons:

- In a bioaccessibility study (please refer to chapter 7.1) it was clearly demonstrated that elemental Red Phosphorus is not bioaccessible via membranes. A dermal absorption is also very unlikely to occur.

- The only bioavailable compounds are oxidized Phosphorus species ((Hypophosphite, Phosphite, and Phosphate) which themselves are essential for several biochemical/metabolic mechanisms and do not have any sensitizing property.

- In literature and QSAR programs there is no hint that elemental Red Phosphorus has any binding tendency to biochemical macromolecules such as proteins and DNA. The initiation of a reaction cascade resulting in an allergenic reaction is very unlikely to occur.

 

Considering all above mentioned data, the substance does not have to be classified as a skin sensitizer.

A classification concerning respiratory sensitizing properties is not warranted as the classification criteria according to EU regulation 1272/2008 and 67/548 are not met.