CEPRA performs analysis on cosmetic products to indicate on the label "Nickel Tested (or Nickel Tested)".
The law does not indicate limits for the presence of nickel in cosmetics. But it is believed that people allergic to nickel do not have allergic reactions due to exposure to cosmetics with nickel concentrations lower than 1 ppm, that is to one part per million.
The recommended tolerance limit is 1 ppm (1 mg / kg = 0.000001).