CFR › Title 21 › Part 346 › §346.1821 CFR §346.18Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkThe active ingredient of the product consists of any of the following when used within the concentration range established for each ingredient:(a)Calamine, within a concentration range of 5 to 25 percent by weight per dosage unit (based on the zinc oxide content of calamine).(b)Witch hazel, 10 to 50 percent.(c)Zinc oxide, within a concentration range of 5 to 25 percent by weight per dosage unit.