The Quest Aqua Tabs have a formulation containing dichloroisocyanurate, an organic chlorine donor with superior disinfection capacity.Effervescent water purifying tablets, each tablet will purify 5 gallons/25 litres of water. Approved by the WHO for drinking water purification.Purifies water - rapid dissolvingFoil wrapped - for protection when not in useOrganic chlorine donorSuperior disinfection capacityEach tablet purifies 25L of waterRemain stable for 5 years plusCertified to NSF/ANSI 60 Standards