All About Hydrogen Peroxide
Discovered in 1818, hydrogen peroxide (H2O2) became commercially available in the 1880s. An early application was bleaching straw "boaters," the hats so popular around the turn of the century. Over 100 years later it is still widely used as a bleaching and brightening agent for natural fibers such as straw, cotton, silk, and even human hair, but mostly wood pulp and paper.
Hydrogen peroxide has many diverse applications outside of textile and paper production including mining, the manufacture of chemicals and semiconductors, the operation of cooling towers and once-through cooling water systems, food processing, pollution control, and pool/spa water-maintenance programs. More preparations are found in toothpaste and mouthwash, antiseptic swabs, and household cleaners. One attraction is that H2O2 is an oxidizing biocide. It will kill bacteria, fungi, and viruses. While less effective on its own than chlorine or bromine, it has the advantage of decomposing to water and oxygen without adding dissolved solids to the system.
Taylor offers simple drop tests for monitoring hydrogen peroxide at both low and high concentrations. Choose K-1825 (2 oz. reagents) or K-1826 (.75 oz. reagents) for a drop equivalency of 5 ppm. For testing higher levels choose K-1443 (2 oz. reagents), where 1 drop = 0.5% or 1%, depending on the sample size. In these titrations, the color change is from yellow/orange to colorless at the endpoint. Remember: 1% of any solution is 10,000 ppm.