There is no such thing as “away”. When we throw anything away it must go somewhere.
As you have read about biomedical waste in my previous blog. So this is my second blog on procedure, treatment and disposal of biomedical waste management. We have to think of suitable alternatives to tackle this problem. Proper management of biomedical waste ensures safety and hygiene of institutions and communities.
Improper management can cause various viral or bacterial infections. This can lead to form resistant organisms or pathogens. This further leads the organisms to our door steps. So, prime attention should be on proper and safe disposal of these wastes.
There’s a lot of confusion among different levels of management. It can be due to inappropriate awareness. It’s mentioned in the Springer journal, in 2002, an assessment ran by W.H.O in 22 developing countries. It found that 18% to 64% of healthcare facilities don’t use proper disposal methods.
The Biomedical Waste (Management and Handling) July 1998 is the guideline issued by Indian government. That is for safe management from storage to disposal of the biomedical wastes. This rule has undergone revision and modification. Biomedical Waste Management in March 2016 is the latest amended edition. Under this rule steps are defined for the proper management of biomedical wastes. I have mentioned these steps in detail below :
Procedure of Biomedical Waste Management
The crucial steps for scientific and proper management of biomedical wastes are:
- Accumulation and storage
- Disposal of waste
I have mentioned these steps in detail below :
Observation of Biomedical Waste
Observation of waste
Waste should be observed carefully,from the point of generation to type of waste. Level of generation and disinfection determines the process of treatment of waste.
Segregation of waste
Separation of different types of waste is essential. It reduces the risk of infection among workers and the public. In addition, it avoids physical injury. Color coding is not only for us. It represents the basic principle that all the waste is not the same so they will not end up in the same place. Different kinds of waste means their treatment process is also not the same. For the intention of segregation colour coded bins are used. Every bin has a distinct waste base on their treatment process and their quality.
It is used to store contaminated wastes that can be recycled. These bags or bins should be non chlorinated since chlorinated bags can react with the waste. These are used for collection of following:
- Plastic IV bottles and sets
- Rubber gloves
- Specimen containers
- Infected plastics
- Lab wastes
- Microbiology culture
- Used discarded blood bags/ blood products
- Vaccines, etc.
The yellow coloured bins are used to store many type of wastes like:
- Pathological waste
- Solid (infectious) waste
- Medical Chemical waste
- Clinical Lab wastes
- Pharmaceutical waste
These waste are stored in differently marked bins. Biohazard, radioactive, and cytotoxic marks are some examples of different marks. Some examples that comes under this category are mentioned below :
- Human anatomical wastes
- Expired medicine waste like cytotoxic drugs along with vials
- Liquid wastes
- Disinfectant wastes
- Silver X- ray liquid
- Formalin solutions
- Infected secretions
- Aspirated body fluids
- Floor washing liquids
- Liquids from laboratories
- Soiled cotton swabs, bandages, dressing pads, contaminated gauze piece
- Discarded linen beddings and mattress
- Biotechnological or microbiological lab wastes, etc.
White Bins :-
These are white or translucent puncture proof bags. These bags are used to store sharps like :
- Syringes with fixed needles
- Needle from needle cutter or burner
- Contaminated sharp metal objects, etc.
Blue bins are used to store glassware whether medicinal or general. Some example are like:
- Infected broken glass/ bottle
- Broken or unbroken glass
- Glass IV bottles
- Glass injections
- Metallic body implants
- Glassware used in wards
- Glass injections or syringes, etc.
Accumulation and Storage
Storing waste is for collection purposes. Accumulation stands for holding of waste for a short time near the point of waste generation. Storage stands for long term storing of wastes near the waste treatment or disposal site.
Transportation of waste
Wastes are mobilized from generation point to treatment, disposal site via designated vehicle. To avoid public exposure, smell and microbes, containers must always be covered. All the vehicles used by CBWTF operators should not be sub-letters. Operators cannot use a contract vehicle. CBWTF operator’s vehicles should only be used for waste collection purposes. CBWTF operators vehicles should be registered under Motor Vehicle Act with the R.T.O/ Transport Department. Such vehicle numbers should be registered with respective SPCB/ PCC. Closed vehicles should be used.
Treatment of waste
Treatment signifies the modification of waste before sending it to its final resting place. Treatment should be at the source of generation. Treatment is making waste safe, through some process to make it no longer a source of pathogen. Some of the processes are like bleaching, shredding, and chemical disinfecting. Indian govt. has issued a set of guidelines for waste treatment. After treatment the residual can be transported to their disposal site. Some common treatments of waste are:
- Needles and syringes nozzles should shred into a needle destroyer or syringe cutter.
- Glassware should be clean, disinfected and sterilized.
- Scalpel, razor, blades, broken glass should be stored in a puncture proof container with bleach. Then transferred into labelled plastic or cardboard box . These boxes should be sealed to prevent spillage, and further send it to incubators.
- Culture plates are disposed of into appropriate bags. And plates should be autoclave and then sterilized. Sterilized plates can be reused.
- Gloves must be shredded, mutilated, cut and destroyed; before disposal.
- If swabs contain only a small amount of blood that doesn’t drip they can be put into dustbins.
- If swabs contain infected blood it should be disinfected through chemicals. Then proceed to the incinerator.
- Disposable items should be dipped into 1% solution of sodium hypochlorite for 30 mins to 1 hour. Then mutilated and proceed for further disposal.
- Non- infectious liquid waste are neutralize with reagents and then disposed off.
- Liquid infectious wastes are treated with chemical disinfectant and neutralized.
Disposal of Biomedical Wastes
Disposal methods differ in availability, efficiency, cost effectiveness and impacts on the environment. Biomedical waste should be pathogen free before disposal. This should ensure utmost public health and hygiene.
Less developed countries are advised to use solar heating systems for disinfecting infectious wastes. This method results in considerable reduction in the number of viable bacteria but not completely. That still poses a threat. Disposal without treatment is non- advisable for anatomical, sharps and waste from labs. Various disposal methods are:
This is a process of burning of waste at a high temperature. Temperature in incinerators ranges from 1,800 degree F to 2,000 degree F (982 degree C to 1093 degree C). Incinerators have advantage of quick, easy disposal methods.
But their major concern is due to emission. Many states and localities have postponed the use of incinerators for the time being. Until further information on safety options are available.
Autoclaving is comparable to steam sterilization. It is the most commonly used alternative to incineration. It is cost effective as well as has no reported health impacts. Waste is sterilized or disinfected before dumped in landfills. Waste bags are placed in chambers. Then steam is started for a specific time at definite temperature and pressure.
This method has assurity in destruction of microorganisms. Approx 90% of biomedical wastes are suitable for autoclaving particularly microbiological wastes. Autoclaving is not suitable for cytotoxic, pathological, radiotoxic or other toxic chemical wastes.
In this process, medical waste is placed into an empty air-tight chamber. Treated with a sterilizing agent (such as ethylene oxide or formaldehyde). Gas emitted from these chemicals comes in contact with waste. In turn it kills harmful, infectious agents.
EPA does not recommend ethylene oxide for infectious waste because of its toxicity.
4). Chemical disinfection:
This method is preferred for liquid waste; it can also be used for solid waste. In this method chemical agents are use for disinfection of wastes like chlorine.
There are various factors considered about the effectiveness including :
- Type of disinfectant used
- Degree of contamination
- Type and morphology of microorganisms
- Chemical’s concentration, quantity, contact time and requirements for mixing
Alternatives are grinding of wastes before introduction with liquid chemical disinfectant. Grinding confirms sufficient subjection of chemical disinfectant to all parts of waste. That aids in easy disposal of residues. The resulting liquid is drained into sewers and solids are dumped into landfills.
Microwave technology can also disinfect wastes. Wastes are first placed into a shredder. This wastes are mixed with water and internally heated that neutralizes present biologicals. Microwave units are controlled through computers. That ensures least parameters of infection and proper equipment function. 90% of medical wastes can be autoclaved.
Amount of residue produced is low because of shredding. Requires less energy than incinerators.
This method involves waste sterilization by exposing waste to cobalt sources. Cobalt emits gamma rays that kill all the microbes in wastes.
Commercial companies don’t use this technology due to high cobalt cost and operating cost. Some queries are on efficiency on proper disinfecting and radiating materials with rays. It is not recommended for pathological wastes.
7). Thermal Inactivation:
This process involves heat waste at high temperature resulting in killing of microbes. These methods are advised for treating large amounts of liquid wastes. A chamber is preheated to an intense specific temperature at a specific amount of time and then released.
Safe and effective management of biomedical waste is not only a lawful obligation but also a civil duty. Appropriate gathering and segregation of biomedical wastes are vital. The quantity of waste generated is also critical. Lesser quantity of biomedical waste signifies less burden on disposal work. That would be more money and labour saving and a more well structured waste disposal system.
We should step up effort to reduce the waste generation in day to day work in clinics and hospitals.
In my next blog i will be covering biomedical waste management problems and their solutions. If you want legal procedure in handling of biomedical waste you can see our blog Disposing Biomedical Waste: Authorities’ Guidelines
The benefits of biomedical progress are obvious, clear and powerful. The hazards are much less appreciated.
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