Potable Aqua Drinking Water Germicidal Tablets are intended for emergency disinfection of drinking water. When used as directed, they make most water bacteriologically suitable for drinking. Used worldwide by campers, hikers, militaries, emergency organizations and anyone needing to drink water of questionable bacteriological quality. Potable Aqua is for use only when drinking water is suspected or known to be bacteriologically substandard. Not to be used on a continuous basis. For short term or limited emergency use only.