Viability of commercially available bleach for water treatment in developing countries.

Treating household water with low-cost, widely available commercial bleach is recommended by some organizations to improve water quality and reduce disease in developing countries. I analyzed the chlorine concentration of 32 bleaches from 12 developing countries; the average error between advertised and measured concentration was 35% (range = -45%-100%; standard deviation = 40%). Because of disparities between advertised and actual concentration, the use of commercial bleach for water treatment in developing countries is not recommended without ongoing quality control testing.