Concentration of hydrogen peroxide :
The concentration of hydrogen peroxide varies according to the application. However, the maximum permissible oxidation value of 12% should not be exceeded in order to protect skin and hair. To avoid uneven color results, a lower concentration should be chosen in the area of the hairline, i.e. the scalp, because the heat of the scalp accelerates the oxidation process.
Concentrations can be classified as follows:
1% - 2%: very low concentration.
3% - 4%: low concentration.
6%: medium concentration.
9%: high concentration up to.
12% and higher : very high concentration.