A method of preventing contact allergies includes using at least one amphoteric chelating agent which includes a complex based on aluminium and on ethylenediaminetetraacetic acid or the trisodium salt thereof, having the general formula [Al(Y)Bn]c&prime；Dc with B being OH&minus；, BO2&minus； or H+, Y being a tetracarboxylate which can be protonated four times to form ethylenediaminetetraacetic acid, n being an integer equal to 0, 1, 2 or 3, D being a counterion, preferably Na+, c being an integer equal to 0, 1, 2 or 3 and c&prime； being a relative number having the same absolute value as c. A device, a part of which includes the amphoteric chelating agent, is also described.
