Gaikowski, M.P. and J.J. Rach. 1996. Safety of hydrogen peroxide treatments on fish eggs. 
American Fisheries Society-Fish Health Section meeting in Madison, Wisconsin on August 6-9.

Hydrogen peroxide is considered a Low Regulatory Priority (LRP) compound by the U.S. Food 
and Drug Administration for control of fungal infections on fish eggs.  The LRP limit is currently 
500 uL/L with no specified exposure time limit.  We studied the treatment profiles of hydrogen 
peroxide in Heath, egg jar, and Clark-Williamson egg incubators during treatments intended to 
deliver an effective treatment regimen of > 500 uL/L (i.e., treatments of 500 and 1000 uL/L) for 
15 minutes.  Hydrogen peroxide concentrations decreased with increasing distance from the 
influent water in both Heath and Clark-Williamson incubators.  The top treatment tray (tray 2) of 
the Heath incubator received >90% of the intended regimen during the 500 uL/L treatment, 
whereas all trays had hydrogen peroxide concentrations > 500 uL/L for 15 min during treatment 
at 1000 uL/L.  None of the compartments in the Clark-Williamson incubator received the 
intended therapeutic regimen.  The egg jar incubator efficiently delivered the intended 
concentration for the designated treatment period in all jars except for those located directly 
below the influent water.  Our results indicate that dilution of therapeutants applied in certain 
hatchery incubators significantly decreases the efficacy of treatments and may render them 
ineffective.  We recommend that aquaculturists assess the dilution characteristics of their 
incubators in order to ensure proper delivery of all intended chemical concentrations and 
exposure regimens.  Suggestions for maintaining the minimum effective concentrations in 
evaluated incubators are included.