Products
Hydrogen peroxide solutions are available in pharmacies and drugstores as open-use products in medical or technical grade up to 35%. Concentrated solutions (30%) are usually in stock, and common dilutions (e.g., 3%, 6%, 10%) can be prepared or ordered ad hoc in the facility’s laboratory. The specialized trade purchases hydrogen peroxide from specialized suppliers. Hydrogen peroxide is also found in finished pharmaceuticals, cosmetics, hair dyes, tooth whiteners (in the form of carbamide peroxide), toothpaste, contact lens solution, stain removers, specialty detergents, and other parapharmaceuticals.
Structure and properties
Hydrogen peroxide (H2O2, Mr = 34.0 g/mol) exists as a clear, colorless liquid and as an aqueous solution in various concentrations. It is arbitrarily miscible with water, odorless or may have a slight to pungent odor of ozone. It is the simplest and best known representative of the peroxides. The European Pharmacopoeia defines two concentrations:
- Hydrogen peroxide solution 30% contains not less than 29.0 and not more than 31.0 percent (/) H2O2.
- Hydrogen peroxide solution 3% contains a minimum of 2.5 and a maximum of 3.5 percent (/) H2O2.
Effects
Hydrogen peroxide (ATC D08AX01) has antiseptic and antibacterial properties against germs. It is irritant, oxidizing (partly reducing), bleaching and odor eliminating. It also foams and cleans wounds mechanically. The effects last only a short time, depend on the concentration and are based on the release of oxygen. Hydrogen peroxide is broken down to water and oxygen:
- 2 H2O2 (hydrogen peroxide) 2 H2O (water) + O2 (oxygen)
Decomposition occurs via oxygen radicals. It is reactive and decomposes or reacts on contact with oxidizable, organic substances or metals (eg copper, iron) and in alkaline solution. Metals, metal salts, carbon, catalysts (catalase), light, agitation, and heat promote decomposition. Therefore, stabilizers such as acids (phosphoric acid) or metal chelators are added to the solutions. The solutions should be stored protected from light, contaminants, and heat. If they do not contain a stabilizer, they should be stored below 15°C. According to DMS, hydrogen peroxide 3% stabilized with phosphoric acid has a shelf life of 12 months. Hänseler indicates an expiration of approximately 3 years for the stabilized concentrated solution.
Areas of application
Hydrogen peroxide is used medically as a disinfectant and for wound cleansing in concentrations ranging from 1.5 to 6%. Its use is controversial, especially in chronic wounds, because it may delay wound healing. On the other hand, hydrogen peroxide is an endogenous substance with numerous positive effects. It is also used, among other things, as a mouthwash (e.g. 1.5%) and for teeth whitening. These uses are also not undisputed due to the possible undesirable effects. Technically or cosmetically, it is used, for example, as a cleaning agent, as a chemical, for water treatment, as a bleaching agent for paper, hair, furs and textiles. In hunting areas, it is a popular agent for bleaching antlers and bones.
Dosage
According to the package insert or professional instructions. Because concentrated hydrogen peroxide causes burns, it is important to use the proper dilution.
Precautions and adverse effects.
Concentrated solutions are irritating and harmful, causing burning burns to the skin, mucous membranes, and respiratory tract with a white crust. In case of skin or eye contact, rinse immediately with plenty of water. The solutions must not be ingested or inhaled and may cause severe eye damage on contact. Because they release oxygen when heated, they may cause fires or explosions and should not be heated. Hydrogen peroxide is one of the precursors to explosives. When mixed with incompatible substances, explosive decomposition may occur. Refer to the Material Safety Data Sheet and directions for use for complete precautions. When handling concentrated solutions, the precautions mentioned in the Safety Data Sheet must be consistently observed and work must be carried out carefully and cleanly. Always wear gloves and protective goggles.Mouth rinses with H2O2 may cause irritation, oedema, elongation of the filiform papillae of the tongue (black hair tongue), taste disturbance, ulceration, and dry mouth.
