Water purification tablets kill bacteria, viruses & giardia-makes water safe for drinking, brushing teeth, cooking and washing fruits, vegetables and produce.  No unpleasant taste or colour.  Iodine free! Active ingredient (per tablet)is 8.5 mg US EPA approved Sodium Dichloroisocyanurate (NaDCC) equivalent to 5mg/L free available chlorine.  Bilingual package.