Hydrogen peroxide is a chemical compound composed of two hydrogen atoms and two oxygen atoms. It appears as a pale blue liquid in its pure form but is usually available as a colorless liquid when diluted with water. It is known for its strong oxidizing properties, which makes it a powerful disinfectant, bleaching agent, and antiseptic. Hydrogen peroxide decomposes into water and oxygen, especially when exposed to light, heat, or certain catalysts. Because of this, it’s often stored in dark, airtight containers.