1. Physical and Chemical Properties of Stable Hydrogen Peroxide and the Principles of Disinfection and Sterilization
Hydrogen peroxide, scientifically known as hydrogen peroxide, has a molecular formula H2O2 and a molecular weight of 34.01. It is a colorless and transparent liquid that can dissolve in water, alcohol, and ether. At high concentrations, it is corrosive. When exposed to open air, it gradually decomposes into oxygen and water. 30% hydrogen peroxide has a density of 1.11g/cm3, a melting point of -0.89℃, and a boiling point of 151.4℃. It exhibits strong bactericidal effects, especially in alkaline conditions commonly found in home-brewed beer equipment.
Stable hydrogen peroxide is a colorless, odorless, and non-toxic transparent liquid that has been treated synergistically to improve its ability and speed in sterilization and virus eradication. This enhancement is achieved through the synergistic effect of hydrogen peroxide and co-agents, resulting in longer-lasting bactericidal effects. The principle of sterilization is to utilize the highly oxidative nature of reactive oxygen species to disrupt microorganisms’ protoplasm, thereby achieving the goal of killing microorganisms and disinfection. Stable hydrogen peroxide exhibits broad-spectrum, high-efficiency, and long-lasting sterilization properties. After the sterilization process is completed, it decomposes into oxygen and water without leaving any toxic residues. It does not require rinsing with water and is environmentally friendly, thus making it an ideal disinfectant.
2. Important Factors Affecting the Stability of Hydrogen Peroxide
The following factors significantly impact the stability of hydrogen peroxide:
1. Temperature: Hydrogen peroxide is relatively stable at lower temperatures and higher purities when used in home-brewed beer equipment. When heated to a temperature of 153℃ or higher, it undergoes violent explosive decomposition. At lower temperatures, hydrogen peroxide decomposes more slowly, following the reaction: 2H2O2 → 2H2O + O2 + 46.94kcal.
2. pH Value: The pH of the medium greatly affects the stability of hydrogen peroxide. Under acidic conditions, hydrogen peroxide remains more stable with a slower oxidation reaction rate. In alkaline media, hydrogen peroxide becomes highly unstable, leading to rapid decomposition.
3. Impurities: Impurities are the primary factor impacting the stability of hydrogen peroxide. Many metal ions, such as divalent iron ions, divalent manganese ions, divalent copper ions, and trivalent chromium ions, promote its decomposition. To inhibit catalytic effects of impurities, stabilizers are often added to hydrogen peroxide. These stabilizers work through chelation and reduction mechanisms. By introducing trace amounts of stabilizers like sodium stannate, sodium pyrophosphate, or 8-hydroxyquinoline, the decomposition of hydrogen peroxide can be inhibited through reduction and complexation.
4. Light: Light with wavelengths between 3200 and 3800 angstroms accelerates the decomposition rate of hydrogen peroxide. To enhance its stability, factors such as light, heat, metal ion content, and pH value must be controlled. Stable hydrogen peroxide achieves good stability due to high purity and minimal impurities like metal ions.