'50 percent by weight' or '50 wt.% ' means that half of a given amount of this product (e.g. 500 g out of 1 kg) is hydrogen peroxide active ingredient (H2O2). The remainder is water plus small amounts of stabilizers.
Standard grades like our HYPROX® products are typically used for bleaching and other industrial processes. These grades contain sufficient stabilizers to keep decomposition under control in a wide variety of applications. Special grades for chemical synthesis contain less stabilizer compounds, which could interfere with synthetic reactions. Distilled grades include both highly stabilized grades and high purity grades. Cosmetic grades contain high levels of stabilizers for dilution, cosmetic and personal care applications. OXTERIL®, PERTRONIC® and PROPULSE® are all high purity, lightly stabilized grades for use in aseptic packaging, food industry, water treatment, electronic and propulsion applications, respectively.
Our standard procedure to determine the decomposition rate of hydrogen peroxide includes maintaining a sample for 16 hours at 96 °C. A decomposition rate of 5 percent means that after this treatment 5 percent of the original concentration is lost. Thus a 5 percent decomposition of a 50 percent peroxide sample would result in a final concentration of 47.5 percent.
Generally, the purer the dilution water, the better. When hydrogen peroxide is going to be stored or sold after dilution, only deionized water is of sufficient purity. In case of small amounts, diluted for immediate consumption, potable water from municipal water systems may be acceptable as well.
Compared to other chemicals even standard grades of hydrogen peroxide exhibit excellent purity (>99.9 percent). This is based on highly sophisticated production processes including purification steps. Other than the stabilizer package, impurities are mostly expressed as total organic carbon, at levels of milligrams per liter. Most other impurities like anions or heavy metals are well below standard detection limits.
Pressure causing drums to bulge or leak, as well as elevated temperature, usually indicate that peroxide is undergoing a rapid decomposition reaction. Rapid sustained bubbling in any storage vessel indicates a dangerous condition. Bulk storage tanks tend to maintain a relatively constant temperature unless they are close to empty. An internal tank temperature of 40 °C (104 °F) indicates that peroxide may be decomposing at an unacceptable rate so action should be taken to cool the tank. Higher temperatures indicate that cooling is insufficient and that the peroxide should be diluted and/or dumped. If the temperatures rapidly increases further, a catastrophic decomposition is possible, so all personnel should immediately evacuate to a safe area. These are general recommendations to be used as guidance; specific conditions at each customer's site may require other procedures.
Evonik hydrogen peroxide grades have excellent shelf life. If stored at an average temperature of 20 °C, decomposition is less than 2 percent per year based on active hydrogen peroxide. A 50% solution would be at least 49% H2O2 after one year of storage. Storage at higher temperatures can accelerate the decomposition reaction, however, actual experience shows that even lightly stabilized grades of peroxide undergo much less than 2 percent decomposition over a number of years if properly stored.
The main function of stabilizers is to reduce catalytic decomposition induced by transition metals and other contaminants. If the product is diluted, as in 3% topical solutions, or is used in formulations that could accelerate decomposition, a higher level of stabilization is required. If high purity is required, low levels of stabilizers must suffice. Stabilizers are traditionally metal chelating agents and colloids including stannates, pyrophosphates and organophosphonates. Stabilizer levels vary from 0 to several thousand mg/l each depending on the grade.
No, hydrogen peroxide itself does not burn. However, hydrogen peroxide above 60 wt.% is classified as an oxidizer. Hydrogen peroxide may cause a fire if it comes in contact with combustible material.
Stainless steels (304L, 316L, V2A, V4A) or high purity aluminum (5254, 1060) are recommended for permanent storage and delivery systems. Polyethylene (PE, HDPE) is also suitable for this service with certain limitations. PVC is only recommended for temporary use (less than 2 months). Suitable gasket materials are Teflon, Viton, EPDM and Gylon.
Catalase is an enzyme produced by many plants and animals, including all aerobic bacteria, many facultative anaerobes and fungi, that promotes the rapid decomposition of hydrogen peroxide into oxygen and water. When present in process waters containing hydrogen peroxide, it is most active at 21-38 °C (70 - 110 °F) but is deactivated after ten minutes at 77 °C (170 °F).
Hydrogen peroxide concentrations of 10 to 300 ppm under the right temperature conditions with the presence of bacteria will serve to promote the production of catalase (bacterial defenses produce catalase in the presence of peroxide). Peroxide concentrations of 400 ppm or more inhibit the activity of catalase.
Disposal should always conform to local, state, federal and provincial regulations. Depending upon concentration, some peroxide solutions are classified as oxidizers, and/or as corrosive, both with respect to pH and corrosivity. If this is the case, permits may be required to treat peroxide for subsequent safe disposal.
Some on-site biological waste treatment systems can easily tolerate levels up to 100 ppm of hydrogen peroxide, and in some cases the addition of peroxide can augment aeration systems. This process is accelerated by the presence of transition metals, bacteria, catalase and alkaline pH. Be aware, however, that through natural decomposition in some unusual cases, oxygen can build up within pipes and vessels, thus creating the potential for explosive mixtures with methane or other combustible gases.
Our MSDSs comply with international standards. They include information about the product, its classification, its properties, its toxicological data, as well as the recommended safety precautions, first aid procedures and national legislation details. They are available in several languages.
Evonik will only deliver to approved bulk storage locations. Several factors must be considered including proper materials of construction, adequate emergency equipment (eye wash, safety shower, water source etc.) and inclusion of other features such as a relief manway. Sizing of manways generally follows the guideline of 200 cm² per 1,000 kg of peroxide (as 100 percent) capacity. We recommend that all tanks include temperature sensors.
The most important points are proper materials of construction, use of valves approved for hydrogen peroxide service and not including any pipes or vessels that are not vented or otherwise protected against pressure build-up due to peroxide decomposition. Exterior piping may be painted white to avoid unnecessary pressure build-up and resulting discharge through pressure relief devices.
Depending on flow requirements, many different pumps are acceptable (gear, diaphragm, peristaltic). Fluids and diaphragm materials throughout the pump should be compatible with hydrogen peroxide.