Simple and effective purification of drinking water. Effervescent chlorine tablets for emergency purification of drinking water. Water purification tablets make water safe for drinking, cleaning teeth, washing wounds, washing fruit and vegetables etc, by killing the water-borne organisms that cause stomach disorders such as diarrhoea, cholera, typhoid etc.These Oasis Water Purification Tablets are manufactured to an effervescent formulation containing sodium dichloroisocyanurate (NaDCC) - an organic chlorine donor with a superior disinfection capacity to sodium hypochlorite, a near neutral pH and a simple, easy to understand closing system for added safety. Effervescent chlorine tablets are recommended by various aid organizations including the World Health Organisation who include them in their Interagency Health Kit. Simply add one tablet to one litre (1000 millilitre) of suspect water for rapid disinfection. Use when on holiday or travelling on business, camping or in emergencies. Pack contains 50 effervescent tablets. Active ingredient: Sodium Dichloroisocyanurate (NaDCC) 8.5 milligrams per tablet. 5 year shelf life. Dry and non-hazardous to transport. Water Purification Tablets kill bacteria, bacterial spores, cysts, algae, fungi, protozoa and viruses.