Medical Waste Management
• Hospital waste is defined as all waste
generated from medical facilities including
office and kitchen wastes
• Medical Waste Management is of utmost
importance for the safety of the laboratory
personnel as well as the community
Concerns about transmission of HBV and HIV
led to the introduction of ‘universal
precautions’, to minimize the infections in
medical laboratory workers and health care
personnel. These universal precautions
include:
1. Assume that all specimens/patients are 6. Decontaminate the laboratory work
potentially infectious for HIV and other surfaces with an appropriate disinfectant
blood borne pathogens after the spillage of blood or other body
fluids and when the procedures are
completed.
2. All blood specimens or body fluids 7. Limit use of needles and syringes to
should be placed in a leak-proof situations for which there are no other
impervious bags for transportation to the alternatives.
laboratory
3. Use gloves while handling blood and 8. Biological safety hoods should be used
body fluid specimens and other objects for laboratory work.
exposed to them. If there is a likelihood of
splattering, use face masks
4. Wear laboratory coats while working in 9. All the potentially contaminated
the laboratory. Wrap-around gowns materials of the laboratory should be
should be preferred. These should not be decontaminated before disposal or
taken outside. reprocessing.
5. Never pipette by mouth. Mechanical 10. Always wash hands after completing
pipetting devices should be used. laboratory work and remove all protective
clothing before leaving the laboratory.
Biomedial waste
• 80 – 85 % is non-infected waste
• 10 % is infectious
• 5 % is other hazardous waste
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Types of Infectious Waste:
Blood and blood
products in a free flowing,
unabsorbed state
Sharp objects
Laboratory wastes
Unfixed pathological
tissues
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Human Blood & Blood Products
• Any products from the blood; wet or dry
• Universal Precautions: Treat all human blood
and byproducts as if it is contaminated
• Diseases Caused by Blood borne Pathogens:
– HIV / AIDS
– Hepatitis B
– Arboviral infections
– Brucellosis
– Creutzfeldt-Jakob Disease
– Hepatitis C
– Leptospirosis ….. Etc.
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Sharps
• Item that can cause puncture or cut, and
that which has been used in animal/human
patient care or treatment
• Ex. needles, glass, syringes, razors
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Laboratory wastes:
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Laboratory wastes:
• Cultures
• Etiological agents
• Specimens
• Stocks
• Vaccine vials
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Pathological Wastes
• Human pathological wastes - tissues, organs,
body parts, containers of body fluids
– Fixed Pathological wastes are not Infectious
Medical Waste
– Unfixed Pathological wastes must be
incinerated
• wastes containing pathological items must
be appropriately labeled to ensure they are
incinerated
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Animal Waste
• Contaminated animal carcasses, body parts,
animal bedding known to have been
exposed to infectious agents during research
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Other Potentially Infectious
Material
• Any body fluid with visible blood
• Amniotic fluid
• Cerebrospinal fluid
• Pericardial fluid
• Peritoneal fluid
• Pleural fluid
• Saliva in dental procedures
• Semen/vaginal secretions
• Synovial fluid
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• Source Reduction - ways to lessen the
amount of disposal material
– Segregation - keeping noninfectious
waste out of the infectious waste stream
– Minimization - reduce or eliminate waste
at the source
– Engineering controls - methods to reduce
quantity of waste(smaller containers)
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Segregate
• which waste stream an item goes in every
time wastes are disposed
• By properly segregating medical wastes, the
weight of infectious waste can be drastically
reduced in every facility
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Broad Guidelines for use of colour
coded plastic bags:
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Segregation, Packaging,
Transportation & Storage
Bio-medical Wastes:
- Shall not be mixed with other wastes
- Segregated into containers / bags at the
point of generation
- Suitably labeled
- Suitably transported
- Not stored beyond 48 hrs
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Treatment Methods
• 1. Chemical processes - use chemicals that act as
disinfectants. Ex. Sodium hypochlorite
2. Thermal processes – Autoclave
3. Mechanical processes - compaction and shredding
4. Irradiation processes- ultraviolet or ionizing
radiation
5. Biological processes- biological enzymes for
treating medical waste
• 6. Incineration - primary method of treatment
and disposal for biohazardous material
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Waste Treatment
Following techniques are in use for treatment
of infected material.
1. Double Chambered Incineration
2. Autoclaving
3. Microwaving
4. Hydroclaving
5. Plasma torch
6. Chemical treatment
1.Double Chambered Incineration
Contains 2 chambers:
Waste is burnt in one chamber (primary
chamber) at 800°C
Combustion of gases emitted from the 1st
chamber, occurs in the secondary chamber
The negative pressure is maintained inside the
incinerator system, thereby forcing the end-
gases out of the chimney
Advantages:
The incinerator deals with all pathological and
cytotoxic wastes, body parts, animal waste,
microbiological waste and solid dressings
Disadvantages:
• Generates highly toxic gases
• Recyclng and reprocessing of materials cannot
be done
2. Autoclaving
Relies on the circulation of steam through the
infectious waste to decontaminate it.
• two types depending on the method they use
for removal of air pockets: gravity flow
autoclave and vacuum autoclave.
• 121 C and pressure of about 15 pounds per
square inch (psi) for more than 60 minutes
• 135 C and a pressure of 31 psi for more than
45 minutes
• 149 C and a pressure of 52 psi for more than
30 minutes
• Uses- microbiological waste, blood and blood
products, body fluids and used sharps
• Disadvantages:
– Not recommended for pathological waste
– Has a large strain on landfill capacity
3. Microwaving
• Radiations produced by the microwave are
involved to break apart molecular chemical
bonds and thus disinfect infectious waste
• Microwaves heat the waste to 97° to 100°C for
40-46 minutes
Advantage:
Disinfects waste without hazardous emissions
Disadvantage:
Cannot be used to treat body parts and tissues
4. Hydroclaving
• high heat process (800-1000 C) for 1 hour
• steam treatment with fragmentation and
drying of waste
• Advantage:
– waste can be safely recycled or land filled
– all items including pathological wastes can be treated
5. Plasma Torch
• very high temperature
• expensive but safe
Advantage:
no need for segregation
6. Chemical Treatment
Use chemicals that act as disinfectants.
Sodium hypochlorite, dissolved chlorine
dioxide, peracetic acid, hydrogen peroxide,
dry inorganic chemical and ozone are
examples of such chemical
Treatment Methods Used for
Infectious Wastes
Type of infectious Steam Incineration Chemical
waste (autoclave)
Microbiological Waste + + +
Human blood, blood + + _
products, body fluids
Pathological waste _ + _
Used Sharps + + _
Clean up of infectious + + _
waste spill
Animal Carcasses _ + _
Disposal
• Infectious wastes after treatment can be
disposed of by land-filling or deep burial
• Liquid waste can be disposed in sewage drains
• Beside treatment incineration is also a
method of disposal
Disposal of Sharps
• Blades and needles waste after disinfection should
be disposed in circular or rectangular pits.
• pits can be dug and lined with brick, masonry, or
concrete rings
• covered with a heavy concrete slab, of upto 20 mm.
• When the pipe is full it can be sealed completely
after another has been prepared
Improper Management due to:
a) Improper handling; Unsafe actions: handling
without personal protective equipment (PPE),
b) Poor storage (e.g. high temperature conditions
combined with prolonged storage time before
treatment),
c) Manual Transportation for longer distances.
d) Use of uncovered containers instead of closed
plastic bags
e) Exposure times beyond acceptable limits and
f) Lack of adequate worker and equipment
decontamination process/procedures
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Guidelines to reduce the risk of exposure:
• Frequent hand washing
• Use of standard barrier precautions
• Regular cleaning and decontamination of
work surfaces with a cleaning agent labeled
as effective against Mycobacterium/TB
• Vaccination against Hepatitis-B
• Proper infectious waste disposal
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Improper Disposal May Lead to:
• rag pickers may repack waste or left over
drugs and sell them
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