How It’s Used Hydrogen peroxide (H2O2) in its pure form it is a colorless liquid, slightly more viscous than water; however, for safety reasons it is normally used as an aqueous solution. The compound is thermodynamically unstable, decomposing to oxygen and water, especially at higher concentrations and temperatures (it has been used as a rocket … Continue reading Hydrogen Peroxide—and Hydrogen Peroxide Monitoring Instrumentation