Hydrogen peroxide
![Phase diagram of H2O2 and water: Area above blue line is liquid. Dotted lines separate solid+liquid phases from solid+solid phases.](/Images/godic/202412/18/Phase_diagram_hydrogen_peroxide_water.svg2824.png")
![Structure and dimensions of H2O2 in the gas phaseStructure and dimensions of H2O2 in the solid (crystalline) phase](/Images/godic/202412/18/H2O2_gas_structure.svg2825.png")
![O−O bond length = 145.8 pm O−H bond length = 98.8 pm](/Images/godic/202412/18/H2O2_solid_structure.svg2825.png")
![](/Images/godic/202412/18/Riedl-Pfleiderer_process.svg2825.png")
Hydrogen peroxide is a chemical compound with the formula H
2O
2. In its pure form, it is a colourless liquid, slightly more viscous than water; however, for safety reasons it is normally used as an aqueous solution. Hydrogen peroxide is the simplest peroxide (a compound with an oxygen–oxygen single bond) and finds use as a strong oxidizer, bleaching agent and disinfectant. Concentrated hydrogen peroxide, or "high-test peroxide", is a reactive oxygen species and has been used as a propellant in rocketry.