Chapter 2:
Hydrogen Peroxide Hazard Classifications
• Various governmental agencies have established rules and regulations covering the transportation, storage and handling of hazardous materials such as H2O2. The rules are based on a classification rating system which considers many factors, such as risks to employees, the public, the environment, and property. You should check with your local fire department and environmental health agency for specific guidance.
• Depending on its concentration, H2O2 may be considered an Oxidizer (fire hazard), a Corrosive (health hazard), and/or Unstable/Reactive (explosion hazard). Also H2O2, concentration can mean the difference between toothpaste and rocket fuel. In general, small quantities of high strength H2O2 may present a greater hazard than large quantities of low strength H2O2.
• Less than 8% concentration H2O2is considered a non-hazardous substance. Typically encountered versions
are baking soda-peroxide toothpaste (0.5%), contact lens sterilizer (2%), over-the-counter drug store
Hydrogen Peroxide (3%), liquid detergent non-chlorine bleach (5%) and hair bleach (7.5%).
• At 8% to 28% H2O2 is rated as a Class 1 Oxidizer. At these concentrations H2O2is usually encountered as a
swimming pool chemical used for pool shock treatments.
• In the range of 28.1% to 52% concentrations, H2O2is rated as a Class 2 Oxidizer, a Corrosive and a Class 1
Unstable (reactive) substance. At these concentrations, H2O2
is considered industrial strength grade.
• Concentrations from 52.1% to 91% are rated as Class 3 Oxidizers, Corrosive and Class 3 Unstable (reactive)
substances. H2O2at these concentrations are used for specialty chemical processes.
• At concentrations above 70%, H2O2 is usually designated as high test peroxide (HTP).
• Concentrations of H2O2 greater than 91% are currently used as rocket propellent. At these concentrations,
H2O2 is rated as a Class 4 Oxidizer, Corrosive and a Class 3 Unstable (reactive) substance.
Federal Hazard Ratings
The following entry lists the hazard ratings of various strengths of H2O2, according to the Code of Federal Regulations, Title 29. Where numerical classifications are included, they are in accordance with nationally recognized standards.
| <8% | Examples: | Baking soda - peroxide toothpaste (0.5%) Contact lens sterilizer (2%) Over-the-counter drug store Hydrogen Peroxide (3%) Liquid detergent bleach (5%) Hair bleach (7.5%) |
|---|---|---|
| Rating(s): | Non-hazardous | |
| 8%-28% | Examples: | Pool shock (27%) |
| Rating(s): | Oxidizer - Class 1. An oxidizer whose primary hazard is that it slightly increases the burning rate but does not cause spontaneous ignition when it comes into contact with combustible materials. | |
| 28.1%-52% | Examples: | Most industrial strength grades. |
| Rating(s): | Oxidizer - Class 2. An oxidizer that will cause a moderate increase in the burning rate or that may cause spontaneous ignition of combustible materials with which it comes into contact. Corrosive. A substance that "burns" skin and tissue when it comes into contact with them. Unstable (reactive) - Class 1.(35 - 52% H2O2). Materials which in themselves are normally stable but which can become unstable at elevated temperatures and pressures. |
|
| 52.1%-91% | Examples: | Specialty chemical processes, shipping to very large users (70% shipped and diluted/stored onsite at < 52%). |
| Rating(s): | Oxidizer - Class 3. An oxidizer that will cause a severe increase in the burning rate of combustible materials with which it comes in contact or that will undergo vigorous self-sustained decomposition due to contamination or exposure to heat. Corrosive. A substance that "burns" skin and tissue when it comes into contact with them. Unstable (reactive) - Class 3. Materials which in themselves are capable of detonation or of explosive decomposition or explosive reaction but which require a strong initiating source or which must be heated under confinement before initiation. This degree includes materials which are sensitive to thermal or mechanical shock at elevated temperatures. |
|
| >91% | Examples: | Rocket propellant |
| Rating(s): | Oxidizer - Class 4. An oxidizer that can undergo an explosive reaction due to contamination or exposure to thermal or physical shock. In addition, the oxidizer will enhance the burning rate and may cause spontaneous ignition of combustibles. Corrosive. A substance that "burns" skin and tissue when it comes into contact with them. Unstable (reactive) - Class 3. Materials which in themselves are capable of detonation or of explosive decomposition or explosive reaction but which require a strong initiating source or which must be heated under confinement before initiation. This degree includes materials which are sensitive to thermal or mechanical shock at elevated temperatures. |
NFPA Hazard Ratings
A companion rating system has been devised by the National Fire Protection Association (NFPA) to assist emergency responders - NFPA 704 - 1990. The system has also been incorporated into the Uniform Fire Code, Standard 79 - 3. This program utilizes a color-coded tank/site placarding system that visually alerts first responders to the types of hazards associated with the material (e.g., health, flammability, and reactivity). The appropriate labellings for various H2O2 concentrations follow. Note that the subsequent explanations include only those relevant to H2O2 - users should consult the actual regulations (or their local fire department) in determining all the compliance requirements).
| H2O2 Conc. wt.% | Health | Flammability | Reactivity |
|---|---|---|---|
| < 8 | 0 | 0 | 0 |
| 8 - 20 | 1 | 0 | 1 |
| 20 - 52 | 3 | 0 | 1 |
| 52 - 91 | 3 | 0 | 2 |
| > 91 | 3 | 0 | 3 |
Health
0 - Materials that on exposure under fire conditions would offer no hazard beyond that of ordinary combustible material.
1 - Materials that on exposure would cause irritation but only minor injury.
2 - Materials that on intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury.
3 - Materials that on short exposure could cause serious temporary or residual injury.
4 - Materials that on very short exposure could cause death or major residual injury.
Flammability
0 - Materials that will not burn.
Reactivity
0 - Materials that in themselves are normally stable, even under fire exposure condition, and which are not reactive with water.
1 - Materials that in themselves are normally stable, but which can become unstable at elevated temperatures and pressures.
2 - Materials that readily undergo violent chemicals change at elevated temperatures and pressures or which react violently with water or which may form explosive mixtures with water.
3 - Materials that in themselves are capable of detonation or explosive decomposition or reaction but require a strong initiating source or which must be heated under confinement before initiation or which react explosively with water.
Significantly, no concentration of H2O2 is listed as a CERCLA-regulated substance (i.e., a persistent environmental hazard). If released to the environment, H2O2 will decompose to oxygen and water with concurrent generation of heat. Nor are the standard industrial strengths of H2O2 (those < 52% wt.%) covered under the Federal Risk Management guidelines. However, a hazardous material permit - termed a Hazardous Materials Inventory Statement (HMIS) - may be required by local response agencies, depending on the concentration, volume, and location of H2O2 stored. Again, you should check with your local fire department and environmental health agency for specific guidance.