Safety and environmental requirements continue to have a dramatic impact on the methods used to treat recirculating cooling waters. Legislation such as that prohibiting the use of hexavalent chrome, the "Clean Water Act" and the Superfund Amendments Reauthorization Act (SARA) have all represented strong driving forces to consider alternative treatment technologies. These changes have had a direct impact on the choice and application of oxidizing biocides. Safer alternatives to gaseous chlorine and better application technology for oxidizing biocide alternatives have become major topics of concern.

This document will cover the use and application of the four major oxidizing biocides used in treating cooling waters: chlorine, bromine, chlorine dioxide, and ozone. The document will help end users and all personnel involved in treating cooling systems to better understand the chemistry, the application methods and the safety and environmental issues concerning oxidizing biocides.