Even though only 10% to 25% of health care waste, also known as medical waste, is considered to be hazardous, this small fraction nevertheless requires specialized care. That’s because, depending on where it originated, hazardous health care waste can be toxic, radioactive, or infectious. In order to protect against health and safety risks and to more clearly identify appropriate treatment options, hazardous health care waste is further classified into 10 distinct waste groups. These categories include:
Any waste item that might contain a sufficient concentration of pathogens or toxins to cause disease in a potential host is considered to be infectious waste. Typical examples of infectious waste include dressings or bandages, blood bags, swabs, or any other materials or equipment that have or may have come into contact with body fluids. Body fluids themselves, including urine and blood, are also considered to be infectious waste.
Pathological and anatomical waste
Originating from surgical procedures or research work, pathological and anatomical waste consists primarily of recognizable body parts, organs, and tissues. While these body parts may be perfectly healthy, they are always treated as potentially infectious for precautionary reasons. While the majority of pathological and anatomical waste comes from humans, body parts from other vertebrate animals are included in this category as well. These may come from veterinary hospitals or research facilities that use animal testing.
Hazardous pharmaceutical waste
Any pharmaceutical products, such as drugs and vaccines, that are unused, expired, spilt, or contaminated will fall into the category of hazardous pharmaceutical waste. The hazardous pharmaceutical waste group also includes any discarded items that were used to handle or store pharmaceuticals, like pill bottles or vials, or to connecting tubing from IV drips. Somewhat surprisingly, however, most health care facilities deal with quite small quantities of pharmaceutical waste. This is typically due to country-specific measures implemented by most ministries or health departments that were designed to reduce costly and inefficient drug waste.
Hazardous chemical waste
Hazardous chemical waste is not specifically medical in origin, but it is generated in significant quantities by health care facilities given their rigorous standards of cleanliness. Any discarded chemicals, whether in solid, liquid, or gaseous form, generated during disinfection or cleaning procedures are classified as hazardous chemical waste. Furthermore, such waste items may be corrosive, flammable, or explosive, and they must be disposed of carefully according to their product-specific instructions.
Waste with high heavy metal content
Technically a sub-group of chemical waste, waste items containing significant quantities of heavy metal or heavy metal derivatives nevertheless require special handling and are treated as a separate category. The largest sources of this type of waste in health care facilities are clinical equipment such as thermometers and manometers (blood pressure gauges), which can contain highly toxic amounts of cadmium or mercury.
Aerosol cans or other cartridges or containers of pressurized liquids, gases, or powdered materials are handled in a special way, whether the contents are inert or potentially harmful, due to the chance that such containers may explode if they are accidentally punctured or incinerated. Some of the most common examples of pressurized containers in health care include anesthetic gases; oxygen; and ethylene oxide, which is used to sterilize surgical equipment and other medical devices.
The final four categories of hazardous health care waste are deemed to be highly hazardous and therefore require even more specialized attention and treatment. These waste groups include:
Any items that are capable of causing cuts or puncture wounds are classified as sharps for waste disposal purposes, regardless of whether or not they are infected. With syringes and injection devices, blades, and shards of glass or plastic serving as the most common examples, sharps are considered highly dangerous. Sharps, which are handled as little as possible once they are generated, are packed and handled completely separately from other medical waste in order to ensure personnel safety. Most people who have visited a hospital or medical clinic would recognize a specially designated sharps disposal container: a self-locking and sealable plastic unit, typically red or bright yellow in color.
Highly infectious waste
In addition to body fluids from patients with highly infectious diseases (such as HIV/AIDS), as well as items which may have come into contact with these fluids as described in category 1 above, the highly infectious waste group also includes microbial cultures or stocks of highly infectious agents. Such waste cultures or stocks are typically generated by medical analysis laboratories or testing facilities.
Genotoxic and cytotoxic waste
Many of the drugs used in oncology or radiotherapy units have a high cytotoxic or mutagenic effect. That is, they can increase or influence the frequency of mutations in genetic material. As a result, they pose a significant health and safety risk, particularly in specialized cancer hospitals where they are found in large quantities. Any waste derived from these drugs, as well as bodily discharges from patients being treated with such drugs, requires extremely sensitive handling and disposal.
Radioactive waste is produced through procedures including in vitro organ imaging and tumor localization, in vitro analyses of body tissue or fluids, and other investigative and therapeutic practices. This waste is broadly defined as any substance contaminated with radionuclides. For the most part, health care facilities only generate low-level radioactive waste. That is, the radionuclides in the waste have short half-lives and lose their potency relatively quickly.