H2O2 is the chemical formula for which common antiseptic compound?

H₂O₂ is the chemical formula for hydrogen peroxide, a compound commonly used in dilute solutions as an antiseptic, disinfectant, and bleaching agent.

Each molecule contains two hydrogen atoms and two oxygen atoms. Unlike water, whose formula is H₂O, hydrogen peroxide contains an oxygen–oxygen bond. That bond makes it relatively reactive and allows the compound to decompose into water and oxygen, especially in the presence of heat, light, or catalysts such as the enzyme catalase.

Household hydrogen peroxide is commonly sold as an approximately 3% solution in water. Historically, people used it to clean wounds because it was inexpensive and its bubbling action appeared to lift debris. However, modern wound-care guidance often discourages routine use on open wounds because concentrated or repeated applications can damage tissue and delay healing.

Hydrogen peroxide is also used in surface disinfection, hair bleaching, paper bleaching, wastewater treatment, and industrial chemistry. Concentrated solutions are substantially more hazardous than the dilute product sold for household use.