How to Dispose of Hydrogen Peroxide

Hydrogen peroxide is a common household disinfectant, sold in dilute concentrations of 3% or less. However, at higher concentrations, common in laboratory and industrial settings, hydrogen peroxide has several associated hazards. Proper disposal of hydrogen peroxide, particularly at higher concentrations, is a critical health and safety concern.
In this article, we’ll outline some general guidelines for safe disposal of chemical waste products, and explain how these pertain specifically to hydrogen peroxide. By the end of this article, you’ll understand what hydrogen peroxide is, how it’s used, and how to safely dispose of it.

General guidelines for chemical waste

There are guidelines in place for safe disposal of chemical waste, although these may vary by jurisdiction. For example, in certain jurisdictions, it may be acceptable to dispose of a certain chemical down the drain, while other areas require the same chemical be picked up by a waste management company.

Chemical waste is easily generated due to surplus, expired, or contaminated chemicals. As a laboratory or company working with large amounts of chemicals, you’ll quickly learn to be efficient and minimize chemical waste. Not only is chemical waste hazardous, but disposal can be expensive and resource-consuming.
In general, chemicals need to be placed in a clearly labeled container for hazardous waste. In laboratory settings, this is often an empty solvent jug that has been relabeled according to regulations. Care must be taken to ensure that no incompatible chemicals are mixed together in the waste container, and that all chemicals are labeled on the regulation tag.

Certain chemicals can be neutralized, decomposed, or deactivated prior to waste disposal. In some cases, this chemical process results in an end product that is technically no longer hazardous waste – and is thus much safer and cheaper to dispose of. For example, corrosive acids can be diluted and neutralized with a base to obtain a neutral pH, non-hazardous salt solution. Similarly, concentrated hydrogen peroxide can be diluted and decomposed to break it down into innocuous water and oxygen – leaving you with a much safer material.

What is hydrogen peroxide?

Hydrogen peroxide, or H2O2, is best known to the lay man by its household label – a clear, colorless solution of just 3% hydrogen peroxide in water. Hydrogen peroxide is also found naturally within our cells.

When exposed to heat or light, hydrogen peroxide breaks down to form water and oxygen. This is one of the reasons that hydrogen peroxide is considered an environmentally benign chemical – at least at low concentrations. The chemical reaction looks like this:

2H2O2 -> O2 (g) + 2H2O (l)

What is hydrogen peroxide used for?

At dilute household concentrations, hydrogen peroxide is a household disinfectant that is used in cleaning products or as an antiseptic for wounds.

However, hydrogen peroxide is also sold in much higher concentrations, for a multitude of industrial or business applications. These concentrations pose a much greater hazardous risk, especially for prolonged worker exposure. Some examples of applications using hydrogen peroxide include:

• Food grade surface disinfectant, for example, in a poultry plant
• Coloring products in beauty salons
• Surface disinfectant in hospitals and health care settings
• Manufacture of foam rubber

How to dispose of hydrogen peroxide safely

At low concentrations sold in drug stores – or in general, less than 8% – it is usually permissible to simply flush hydrogen peroxide down the drain.
If you are dealing with higher concentrations of hydrogen peroxide, greater than 5-8%, you will first need to dilute hydrogen peroxide to about 5%. If you are dealing with small quantities, it is usually acceptable to simply flush hydrogen peroxide down the drain.

However, if you are a business who works with large quantities of hydrogen peroxide, and you have somehow generated an excessive amount of waste, you may need to take an additional step following dilution. Remember that hydrogen peroxide can break down into water and oxygen. We can decompose hydrogen peroxide by adding a chemical reagent such as sodium sulfite, sodium metabisulfite, or a related chemical. Once the hydrogen peroxide has been made inert, it is no longer considered hazardous waste and can be safely disposed of. Always check with the chemical waste disposal guidelines in your local jurisdiction to be sure you are complying with regulations in your area.

Lab Alley is pleased to provide you with the highest quality hydrogen peroxide for your industry and laboratory needs. We offer multiple concentrations and sizes, including bulk sizing, and a streamlined online ordering process for your convenience. If you have questions regarding hydrogen peroxide or any of our products, please feel free to contact us for more information.