a brief introduction to biohazard disposal in the US

Dealing with biohazard waste is a part of working in many areas of research. How much do you know about what happens to that waste when it leaves your facilities? This brief introduction explores biohazard disposal and highlights why proper packaging and treatment of biohazard waste are essential.

Biohazard Waste Disposal

Once generated, such waste goes through a specific cycle determined by the guidelines from the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA). The Center for Disease Control (CDC) also offers guidelines for the removal and treatment of biohazard waste that are implemented within the standards and practices of each state, center, university, facility, company, or organization.

Packaging, Classification and Storage

First, you must separate and discard non-hazardous material, such as general healthcare waste. If you cannot avoid mixing non-hazardous and hazardous waste, everything is classified as hazardous and must be dispatched accordingly.

You also need to sort out needles and sharp objects and put them in puncture-proof, tamper-proof containers. It is essential that sharp object containers are not overfilled. Generally, containers should only be filled to three-quarters' capacity.

For infectious waste, as well as small amounts of chemical and pharmaceutical waste, you need to use leak-proof plastic bags or containers bearing the international infectious substance symbol. You can also include low-level radioactive infectious waste if the waste is due for incineration.

Highly infectious waste must be sterilized using autoclaving (high temperatures and high pressures). The containers need to be strong enough to support the process, while highly radioactive waste must be sealed in a labeled lead box that bears the international ionizing radiation symbol. When the waste is in decay, the labeling must include the type of radionuclide, the date of packaging and required storage conditions.

If you are dealing with large quantities of chemical waste, you must collect it in a labeled container that can resist reaction with the chemicals it contains. Chemicals should never be mixed, and should ideally be sent to specialized treatment facilities. However, you need to store anything containing high levels of heavy metals (like cadmium and mercury) separately to other waste.

You need to place cytotoxic waste, waste that has a toxic effect on living cells, in clearly labeled, robust, and leak-proof containers. The containers must then be stored completely separate from any other biohazard waste.

Regardless of the type of waste, all containers and bags should be appropriately labeled with the following information:

• Clear description of the waste
• Appropriate internationally recognized symbols
• Quantity of the waste by volume or weight
• Name of generating facility or organization
• Date of the container’s production

As with sharp-object boxes, you should only fill waste bags to three-quarters capacity. All bags and containers should be sealed tightly (not stapled) and be ready for transport by suitable means to their end destination. When you need to transport waste internally for storage, modes of transportation should be cleaned, disinfected and checked for sharp edges that could damage the waste containers.

Internal storage areas should be separate from areas used for other activities. Non-hazardous waste should not be stored for more than 48 hours in the summer and 72 hours in the winter, depending on the climate. Longer storage is permissible if space is refrigerated. The flooring of the storage room needs to be impermeable, easy to clean and have excellent drainage.

Collection and Transportation

You need easy access to the storage facility for collection, as well as a plan for regular collection of waste with all precautions and transport arrangements in place. The company collecting the waste must meet local regulations, be duly registered and have all required licenses and paperwork. The vehicles themselves should close and lock, and be designed to reduce the risk of damage to the bags or containers. Staff should have suitable protective clothing and the necessary equipment to deal with spills or leaks.

Treatment and Disposal

Biohazard waste is treated to eliminate, or at least reduce, the risks to people and the environment. Treatment must be carried out by a registered company and follow set procedures to ensure there are no adverse effects. Once treated, waste can be transported to a landfill.

There are several ways in which biohazard waste can be treated. One of the most common is through incineration, which involves exposing the waste to temperatures that are high enough to kill any organic substances that may be found in the waste. That includes viruses, bacteria, and other pathogens. The waste is usually converted into ash and gas, and this often needs to be cleansed further before it can be considered harmless and be released.

Autoclaving can also be used to treat biohazard waste. This process uses a chamber that is steam-heated and highly pressurized to sterilize the waste. When used on plastic, the waste can be entirely melted down and completely free of pathogens.

Bleach is also used to disinfect biohazard waste, particularly chlorine-containing compounds. The chemicals in bleach (hydroxy peroxide) start a redox chemical reaction in the chemicals in the waste, rendering the waste non-hazardous (the process is called dichlorination).

Finally, the process of alkaline hydrolysis (more commonly known as biocremation or resomation) can be used. The process is generally carried out by funeral homes as an alternative to cremation or burial. It reduces the emissions of carbon dioxide and other pollutants found in more traditional processes.