Hydrogen peroxide is a powerful oxidizing agent in concentrations over 3%. It is commonly used to treat wounds, but can be decomposed by tissue-based peroxidase enzymes such as catalase. Calcium peroxide is an ingredient in bleaching toothpastes.
Aerobes and many facultative anaerobes produce catalase, which breaks hydrogen peroxide down into water and molecular oxygen, but if enough peroxide is used, it can overwhelm the enzyme and still kill the microbe. The presence or absence of catalase can also be used as a means of separating many cluster-forming and chain-forming cocci, since many members of the Family Micrococciaceae (cluster formers such as micrococci and staphylococci) produce catalase, while the streptococci and enterococci (chain-formers) do not.
Ozone (O3) is a more powerful oxidizing agent than peroxide and can be used to disinfect items such as matresses and water in place of chlorine. Ozone leaves no residue when used and is not carcinogenic, but is more expensive to produce.
Peracetic acid is a liquid oxidizing agent used to sterilize food processing equipment. It is sporocidal and leaves no residue.