The effectiveness of an oxidative sterilization process is determined by exposing a known amount of a primary amine or aldehyde indicator chemical to an oxidative germicide. The oxidative germicide reacts with the indicator chemical. The amount of indicator chemical remaining after exposure to the germicide is determined by reacting the indicator chemical with a dye precursor chemical to form a colored product. The amount of indicator chemical remaining is determined from the intensity of the color of the colored product. The amount of indicator chemical remaining on the substrate is a measure of the effectiveness of the germicidal treatment. The dye precursor is an aldehyde when the indicator chemical is a primary amine and a primary amine when the indicator chemical is an aldehyde. An integrator for determining the effectiveness of the germicidal process includes an indicator chemical, where the indicator chemical is a primary amine or an aldehyde.