When we talk about workplace safety, a lot of the discussion focuses on construction, manufacturing, and natural resource extraction workers and the hazards they face on the job. And while they might not be as evident at first sight, other fields have their own high-risk hazards too. Some so much so, that it wouldn’t be a stretch to say that their whole scope of work is the mitigation of hazards.
This is the case with the medical profession, which is focused on mitigating health hazards we’ve already been exposed to, and which, in the process of ridding us of our ailments, are producing medical waste. Those biohazardous materials have to be disposed of in very particular ways to avoid spreading infections and diseases.
What Is Medical Waste?
Medical waste represents a small proportion (10% to 15%) of the waste produced in healthcare facilities, medical research and training facilities, clinical testing or research laboratories, as well as vaccine production facilities.
For the purpose of this article, we can split medical waste into the following categories:
- Human anatomical waste, which consists of human tissues, organs, and body parts (excluding hair, nails, and teeth). This waste is produced as a result of medical procedures, such as surgeries.
- Microbiology laboratory waste, as the name suggests, is produced in clinical laboratory environments and consists of cultures, stocks, microorganism specimens, prions, toxins, live or attenuated vaccines, human cell cultures, and any material that has come in contact with one of these.
- Human blood and body fluid waste resulting from medical procedures consists of all human blood or blood products, all items saturated with blood, anybody fluid contaminated with blood, and body fluids removed for diagnosis during surgery, treatment, or autopsy. As per the Canadian Council of Environmental Ministers (CCME) guidelines, this excludes urine and feces.
- Sharps waste, such as needles, syringes, blades, or glass contaminated with infectious material that, besides the biohazardous risk, could also cause puncture wounds or cuts.
Disposing of Medical Waste
All medical facilities that create medical waste should have a medical waste management program; the program should not only be included in the healthcare facility’s policy and procedure manuals but should be delivered to all its employees through employee orientation and other in-house educational programs. These programs should include, among others, Workplace Hazardous Materials Information System (WHMIS/GHS) and Transportation of Dangerous Goods (TDG) training.
To avoid the risk of exposure to infections, the facilities generating, handling, and disposing of medical waste should establish written procedures. These facilities should include their employees in the content development process and ensure that employees are aware of and understand the content. Regular training sessions are recommended.
Additionally, all medical waste handlers should always wear adequate PPE to ensure that the harmful agents, being physical, chemical or infectious, are prevented from coming into contact with open cuts or being absorbed through the skin.
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All personnel handling medical waste should also receive a hepatitis B vaccine as well as up-to-date tetanus, diphtheria, and polio vaccines.
The following aspects should be considered when disposing of medical waste:
Due to its hazardous nature, medical waste has to be segregated at the point of generation from general waste and requires decontamination prior to its disposal, to render it harmless and dispose of it as general waste. The medical waste will be segregated into the four categories mentioned above.
While not considered medical waste, cytotoxic and pharmaceutical waste also have to be segregated from regular refuse.
For all categories, if the hazardous waste is mixed with nonhazardous refuse, then the whole batch has to be considered as hazardous waste and disposed of as such.
Medical waste has to be safely packaged at the point of collection. The packaging will protect the handler from contamination and injury when collecting, storing, transporting, and disposing of the medical waste.
Packaging containers can be classified as reusable or single-use containers.
These are intended to be cleaned through a variety of methods, and, as such, have to be sturdy enough to support such treatment. These containers are generally made of metal or rigid plastic and are color-coded, according to the type of medical waste.
|Waste Type||Color Coding|
|Microbiology laboratory waste||Yellow|
|Human blood and body fluid waste||Yellow|
To ensure they are structurally sound and acceptable for reuse, reusable containers should be inspected each time they are emptied, cleaned and, if necessary, their color coding and labeling should be renewed.
Depending on the waste stored, single-use containers can be categorized as:
- Sharps containers Must be solid enough to resist puncture/penetration by the sharp being stored and should be color-coded yellow and bear the biohazard symbol. If they also present a cytotoxic hazard, the cytotoxic symbol should be affixed on the container as well.
- These containers should also have a fill line, a handle to help with their handling, unauthorized access security features, and other measures to reduce the risk of injury. These containers should be placed at the location of sharps disposal, never be filled to over 75% of their usable volume, and sharps should not be pushed into the container by force if they do not easily slide in.
- All personnel collecting and replacing sharps containers need adequate training for the handling of sharps.
- Waste-holding plastic bags These bags have to be color-coded and be sturdy enough to resist puncture in normal operating conditions to contain the waste inside until reaching the point of disposal.
- Cardboard containers These have to be sealable, rigid, leak-resistant, and color-coded according to the waste being handled, and they must bear the biohazard symbol.
In-House Moving and Storage
From its point of generation, medical waste should be moved to a storage place. Moving medical waste increases the chances of container breakage and leakage. We should always strive to minimize the amount of handling, determining safe routes for in-house moving to avoid crossing patient care or clean areas. The carts used for moving medical waste should be designed to prevent spilling and to withstand the rigors of the cleaning treatment.
The in-house storage areas, where medical waste awaits collection, have to be specifically designated for this purpose and no other materials should be stored in the designated room. The room has to be refrigerated, as anatomical waste has to be stored at 4°C (39.2°F) or lower, regardless of the extent of the storage, while all medical waste has to be stored below 4°C if stored for more than four days.
There should be a cleaning procedure for the storage areas that ensures that all surfaces (ceilings, floors, and walls) can be thoroughly cleaned.
Some medical waste, such as human anatomical waste — even after disinfection and decontamination — is still considered medical waste and would require special means of disposal.
Transportation of Medical Waste
In most cases, the disposal of medical waste can’t be done at the source (except blood and body fluids), so medical waste must be transported to the disposal facility. Medical waste is considered to be a hazardous workplace product, and as such, falls under the incidence of Workplace Hazardous Materials Information System (WHMIS) when handled, and under the Transportation of Dangerous Goods (TDS) when transported.
Drivers transporting biohazardous waste should receive adequate training, to allow them to know and apply the regulations regarding:
- Proper loading, unloading, and cleaning procedures.
- The legislated requirements regarding the packaging, safety markings required on the vehicle, as well as the documentation required for each shipment.
- The risks associated with the hazardous waste being transported.
- The proper response to an emergency regarding the waste spill response, reporting requirements, etc.
The transportation of medical waste can’t be made with regular vehicles. The vehicle should have adequate storage compartments to securely hold the medical waste and prevent it from coming in contact with the driver and the general public. The storage area should have a sealed, leak-proof floor, with no window or ventilation opening, and it must be lockable. The storage should be refrigerated when the medical waste is transported over long distances.
Each waste type has to be disposed of in a manner acceptable to CCEM and local environmental regulations. The table below summarizes the disposal options for medical waste:
|Waste type||Landfill||Sanitary sewer||Incinerator||New technologies|
|Human anatomical waste||No||No||Yes||Regulatory approval required|
|Microbiology laboratory waste||No*||No*||Yes||Regulatory approval required|
|Human blood and body fluids||No||If allowed by regulatory authorities||Yes||Regulatory approval required|
|Waste sharps||No*||No||Yes||Regulatory approval required|
|* If decontaminated by a treatment acceptable to local authorities, waste sharps and microbiology laboratory waste can be disposed of in this manner.|
Disposal using new technologies requires regulatory approval before being used. The other three primary methods are as follows.
As shown above, sharps and microbiology laboratory waste can be disposed of in a landfill if local authorities allow this. However, assumptions should not be made and the waste generator should make arrangements beforehand with the landfill operator to determine what waste is acceptable, scheduling, possible limitations on quantity, or what evidence that the waste has been treated is required. Generally, this type of waste has to be buried under a layer of earth or other waste.
Under normal circumstances, blood, suctioned fluids, secretions, and excretions are not considered high hazards. Because of this, they can be safely discharged in a sanitary sewer without undergoing any other treatment.
Since state and municipal guidelines vary, it is recommended that the waste generator verifies with the authorities if this method is acceptable or if any limitations apply. Besides these regulatory variations, the waste generator should also be aware that if the fluids are potentially infected with exotic communicable diseases, this waste should be managed in consultation with the Laboratory Center for Disease Control.
It is also acceptable to dispose of microbiology laboratory waste in the sewer if the waste has been autoclaved or treated with other methods acceptable to the regulator.
Incineration is the only disposal method that can universally be applied to any type of waste. Besides destroying all pathogens due to high temperature, incineration also reduces the waste volume by 90% (or 75% by weight) by converting combustible materials into ash.
The incineration can be done in specially designed incinerators for medical waste, as well as in crematoria incinerators.
Mediating Medical Risk
While the medical profession is radically different from trade-oriented professions, it nonetheless has its own hazards that warrant a fairly similar approach to hazard mitigation. Medical waste is by no means similar to the hazardous products we generally find in construction sites, but because of the harm it can present to its handlers and the general public, its handling, transportation, and disposal must closely follow WHMIS and TDG regulations.
Although it sounds daunting for people outside the medical field, the reality is that the disposal of medical waste is a standard operating procedure for medical facilities. Adequate PPE, policies and procedures, training, containment methods, and means of transportation are required to ensure the safety of all employees involved in the process.