Like all potentially hazardous materials, hydrogen peroxide is subject to shipping regulations and restrictions in the USA. It’s obviously vitally important to consider these carefully for the dual reasons of liability and of safety.
What follows is a guide to some of the regulations that operate in the USA, but this should not be considered to be formal safety or legal advice.
Hydrogen peroxide has a couple of hazardous traits as a chemical substance that make it subject to such regulations and restrictions. The first is its oxidizing power.
As an oxidizer
As one of the strongest oxidizing agents commonly encountered in various chemical environments, hydrogen peroxide is likely to react vigorously and violently with any number of substances with perhaps unpredictable results. As an oxidizer it will enhance the combustibility of many materials, including other chemicals, leading to severe fire risk.
Hydrogen peroxide is a little unpredictable too. It has a whole host of different reactions that at first glance might seem contradictory. For example, it can both encourage and hinder microbial growth. At first this seems like an odd combination, but hydrogen peroxide can be made surprisingly selective and specific just by controlling the conditions under which it is applied. For example, by the careful variation of pH, temperature, the addition of catalysts and by changing concentration, the action of H2O2 can be tailored to a given need. Indeed, concentration is a key factor in terms of its shipping.
One can purchase relatively dilute solutions at any local pharmacy without restriction, but higher concentrations are subject to limitations. As you’ll see below, the concentration of hydrogen peroxide solutions also drives some of the shipping restrictions (or lack thereof).
The second issue associated with hydrogen peroxide is one that is illustrated in the manner that it is often packaged. Hydrogen peroxide solutions of all concentrations tend to be shipped in opaque, plastic containers. You are likely familiar with the brown bottles that can be found in the local drug store. Those solutions are usually 3%, but when we get to 30% solutions an additional feature is added to the distinct bottle; it is concertinaed.
The reason for the opaque, plastic, and concertinaed nature of these bottles can be traced to a single reaction of hydrogen peroxide. In sunlight the solution will break down to form water and oxygen gas according to the reaction below.
2H2O2(aq) → 2H2O(l) + O2(g)
The breakdown of aqueous hydrogen peroxide to other products is a problem not only in terms of the loss of the original material, but beyond that, the creation of any gas in a closed vessel is extremely dangerous. As the pressure builds, the potential for explosion increases as the mechanical strength of the container will ultimately be exceeded. Limiting the exposure to sunlight (via the opaque nature of the bottle), reducing the danger of flying glass (by making the vessel from plastic), and using the concertinaed style to allow the bottle to expand if any gas is produced, all act as safety measures to prevent a dangerous situation.
Specific restrictions and regulations
The rules for shipping hydrogen peroxide are governed by the concentration of the solution. Hydrogen peroxide is readily miscible with water, and easily forms solutions from single digit percent by weight concentrations up to those that exceed 60% by weight.
Solutions of less than 8% by weight
Any hydrogen peroxide solution of less than 8% by weight is not subject to any shipping regulations, and can be shipped without special considerations.
Solutions of 8% to less than 20% by weight
These solutions are subject to labeling and restriction in accordance with UN 2984 (hydrogen peroxide), Class 5.1 (strong oxidizers), and packing group III (substances that represent a relatively minor danger). In this context, oxidizers are considered substances that may contribute to the combustion of other materials, often by the release of oxygen.
Solutions of 20% to less than 60% by weight
These solutions are subject to labeling and restriction in accordance with UN 2014 (hydrogen peroxide), Class 5.1 (8) (strong oxidizers and the additional designation of being a corrosive material) and packing group II (substances that represent a medium danger).
Solutions greater than 60% by weight
These solutions are subject to labeling and restriction in accordance with UN 2015 (hydrogen peroxide), Class 5.1 (8) (strong oxidizers with the additional designation of being a corrosive material) and packing group I (substances that represent a high danger).
As you can see the restrictions and danger both increase with increasing concentration of the hydrogen peroxide solution.
Transporting, loading, and storing
As a strong oxidizer, there are also significant restrictions regarding the substances that hydrogen peroxide can be transported, loaded, and stored with. For example, explosives in HAZMAT categories 1.1, 1.2 and 1.3 must be separated at all times from hydrogen peroxide. Many similar restrictions exist for hydrogen peroxide solutions in combination with other substances.
Packing for transportation
Without specific reference to hydrogen peroxide it may be useful to understand the type packing that is associated with each group mentioned above. What follows is a generic look at the types of packaging that may be required, and does not necessarily represent the specific types of packaging needed for the transportation of the various solutions of hydrogen peroxide.
- Packing group 1 may require a combination of inner and outer packaging, cushioning, and absorbent materials to prevent accidental reaction or spillage.
- Packing group II may require packaging that meets certain specifications in terms of the material it is made from (for example, metal or plastic) and may be limited in size.
- Packing group III may be similar to packing group II, but with less stringent restrictions in terms of material and size of container.