Hydrogen peroxide (H₂O₂) is a clear, colorless, inorganic liquid chemical compound with an acidic pH and in its pure form a pale blue liquid. Because of the complete solubility of hydrogen peroxide in water, solutions of a wide range of concentrations can be made. The amount of H₂O₂ present is expressed as a percent of the solutions weight. Thus, 10 kilograms of a 35% solution contains 3.5 kilograms of hydrogen peroxide and 6.5 kilograms of water.

The chemical peroxide hydrogen is produced today almost exclusively according to the anthraquinone-autoxidation (AO) process. In this AO process, hydrogen peroxide is produced from hydrogen and atmospheric oxygen, whereby an anthraquinone derivative, which is circulated, acts as "reaction carrier". The crude hydrogen peroxide derived through the AO process is then purified and concentrated. After appropriate stabilization, it is marketed as an aqueous solution, usually in concentrations of 35, 50, and 70 percent by weight. Other concentrations or special grades, the purity and stabilization of which are matched to special requirements, are likewise available.