Bromine is an oxidizing chemical that is used for antifouling purposes in such forms as activated bromine, sodium bromide, bromine chloride, and mixtures of bromine and chlorine or other chemicals (Claudi and Mackie 1994), and it is approved for use in the United States for zebra mussel control. It is more effective as an oxidizing agent when water pH is above 8.0 (Fellers, Flock, and Conley 1988). Bromine is also used as a chlorine enhancer designed to minimize the amount of chlorine required to prevent macrofouling, and the proprietary ACTI-BROM® compounds are used in this way. BROMICIDE® and LIQUIBROM™ are other examples of bromine, marketed by Great Lakes Chemical Corporation, West Lafayette, IN.
In the past it was suggested that bromine was less toxic than chlorine to nontarget species, but this has been shown not to be the case (Howe et al. 1994). Total amount of oxidant required for mussel control is approximately the same as chlorine (Claudi and Mackie 1994).
Zebra Mussel Chemical Control Guide
Nonchlorine Oxidizing Chemicals