Schwarzkopf's Igora Zero Amm is a permanent hair coloration that is ammonia-free, offering natural-looking, true-to-tone results with up to 100% white hair coverage. features Amonia-free Odor-free Up to 3 levels of lift 28 shades available Improved coverage, neutralization and highlight performance 100% recyclable tubes and caps how to use Mix Zero Amm shade of your choice with developer at 1: 1 ratio Apply on hair Process for 30-45 minutes Rinse Style as desired