The Katadyn Micropur Water Purification Tablets are only for emergency disinfection of drinking water. When used as directed, the tablets make contaminated water suitable for drinking. The Micropur tablets release chlorine dioxide which is effective against bacteria, viruses and cysts, such as Cryptosporidium and Giardia.FeaturesNo after tasteEasy-to-use tabletMeets EPA microbiological water purifier test standardsEffective against microorganismsSuitable for clear water, cloudy water, or extremely dirty waterLightweight and portable for on-the-go adventures1 Tablet treats 1 Liter of WaterActive ingredients: Sodium Chloride and Sodium Dichloroisocyanurate Dihydrate