Household Water Treatment: Flocculant/Disinfectant Powder, 2011. CDC.
The Procter & Gamble Company developed PUR Purifier of Water™ in conjunction with the Centers for Disease Control and Prevention. PUR sachets are now centrally produced in Pakistan, and sold to nongovernmental organizations (NGOs) worldwide at a cost of 3.5 US cents per sachet. The PUR product is a small sachet containing powdered ferric sulfate (a flocculant) and calcium hypochlorite (a disinfectant). PUR was designed to reverse-engineer a water treatment plant, incorporating the multiple barrier processes of removal of particles and disinfection. To treat water with PUR, users open the sachet, add the contents to an open bucket containing 10 liters of water, stir for 5 minutes, let the solids settle to the bottom of the bucket, strain the water through a cotton cloth into a second container, and wait 20 minutes for the hypochlorite to inactivate the microorganisms.
