Bio - medical Waste Management

Dr.Preyas Joshi

Rajasthan Dental College

05/02/2023 2

LET THE WASTEs OF THE “SICK” NOT

CONTAMINATE THE LIVES OF

“THE HEALTHY”

K.park

CONTENTS

• Definition of Bio medical waste

• Classification of Health Care Waste (WHO)

• Source of Health Care Waste

•Generation/Segregation/Storage/Transportation/

Treatment & Disposal of waste

Treatment technique & categorical treatment.

DEFINITION

• According to Bio-Medical Waste Rules, 1998 of

India, "Bio-medical waste" means any waste,

which is generated during the diagnosis, treatment

or immunization of human-beings or animals, or in

research activities pertaining thereto or in the

production or testing of biological.

Biological Health Hazards

• Dentists constitute a group of professionals who are likely to become exposed to biological health hazards.

• These hazards are constituted by infectious agents of human origin and include viruses, bacteria and fungi.

• From the occupational view point percutaneous exposure incidents particularly needlestick and sharp instrument injuries represents the most efficient method for transmitting blood born infections between patients and health care workers.

• This exposure is related to the fact that dentists work in a limited-

access and restricted-visibility field and frequently use sharp devices.

Percutaneous exposure incidents facilitate transmission of

bloodborne pathogens such as human immunodeficiency virus [HIV],

hepatitis C virus [HCV] and hepatitis B virus [HBV].

• Needles and drilling instruments such as burs represented the most

common devices as the cause of exposure and injury.

• Shah SM et al carried out a study in Washington which revealed that

66.7% of the percutaneous injuries are sustained by dentists and most

of the injuries (70%) occurred during administration of local

anesthesia, recapping a needle and performing surgical procedures.

• In a epidemiological study of needle stick and sharp instrument

accidents in a Nigerian hospital it was found that needle stick accidents

during the previous year were reported by 27% of 474 HCWs,

including 100% of dentists, 81% of surgeons, 32% of nonsurgical

physicians, and 31% of nursing staff. The rate of needle stick injuries

was 2.3 per person-year for dentists.• Shah SM et al. Percutaneous injuries among dental professionals in Washington State. BMC Public Health

2006; 6: 269.• Adegboye AA et al. The epidemiology of needlestick and sharp instrument accidents in a Nigerian hospital.

Infect Control Hosp Epidemiol 1994 ;15(1):27-31.

• Dental environment is also associated with a significant risk of

exposure to various micro-organisms.

• Agents may be present in blood or saliva, as a consequence of

bacterimia or viremia associated with systemic infections.

• Dental patients and Dental Health Care Workers [DHCW] may be

exposed to variety of microorganisms via blood or oral or respiratory

secretions.

• These micro-organisms may include:

Cytomegalo virus

Hepatitis B virus

Hepatitis C virus

Herpes simplex virus types 1 and 2

HIV

Mycobacterium tuberculosis

Other viruses and bacteria, especially those that infect the upper

respiratory tract.

• A DIRECT INFECTION occurs when:

Microorganisms enter through a cut on the skin of hand while performimg a

dental procedure.

Any dental procedure resulting in an accidental biting of the patient.

By the patient, or through a needle wound created while imparting anaesthesia.

• An indirect infection occurs when an infectious agent is transmitted

into the dental care giver through the so-called carrier.

• The following are the main sources of INDIRECT INFECTION:

Aerosols of saliva

Gingival fluid

Natural organic dust particles (dental caries tissue) mixed with air

and water

Accidental breakage of dental instruments and devices

• The following are the main entry points of infection:

Epidermis of hands

Oral epithelium

Nasal epithelium

Epithelium of upper airways

Bronchial tubes

Alveoli

Conjunctival epithelium

• All members of the dental dental personnel team are at risk of

exposure to Hepatitis B virus (HBV), HIV infection, and other types

of communicable infections.

• In the United Kingdom for example, the carrier rate of HBV in the

general population is 0.5%, while dentists have a carrier rate of

approximately 1.6%.

CLASSIFICATION OF HEALTH-CARE WASTEWASTE CATEGORIES DESCRIPTION AND EXAMPLES1.Infectious waste Waste suspected to contain pathogens e.g.

laboratory cultures; waste from isolation wards; tissues (swabs), materials, or equipments that have been in contact with infected patients; excreta.

2.Pathological Waste Human tissues or fluids e.g. body parts; blood and other body fluids.

3.Sharps Sharp waste e.g.: Needle, Scalpels, knives, Blades etc.

4.Pharmacutical Waste Waste containing pharmaceuticals e.g. pharmaceuticals that are expired or no longer needed; items contaminated by or containingpharmaceuticals (bottles, boxes).

5. Genotoxic waste Waste containing substances with genotoxicproperties e.g. waste containing cytostatic drugs(often used in cancer therapy); genotoxicchemicals.

WASTE CATEGORIES DESCRIPTION WITH EXAMPLES

6.Radio-active waste Waste containing radioactive

substances. E.g.: Unused liquid from

radiotherapy or lab research,

contaminated glassware etc.5.Chemical waste Waste containing chemical substances

E.g.: Laboratory reagents; Film

developer; Disinfectants that are

expired or no longer needed etc.8.Pressurized container Gas cylinder, Aerosol cans etc9. Waste with high content of heavy metals.

Batteries; Broken thermometers etc.

SOURCE OF HEALTH CARE WASTE

• Governmental Hospital

• Private Hospital

• Nursing Homes

• Physician’s Office

• Dentist Office

• Dispensaries

• Mortuaries

• Blood Bank and collection center

• Animal Houses

• Laboratories

• Research Organizations

GENERATION,SEGREGATION,COLLECTION,STORA

GE, TRANSPORTATION AND TREATMENT OF WASTE 1.GENERATION:

TYPE SITE OF GENERATION

DISPOSAL BY

Non-Hazardous waste/General waste

Office, Kitchen, Administration, Hostels, Stores,Rest rooms etc

Municipal/Public Authority

Hazardous (Infectious & toxic waste)

Wards, Treatment room, Dressing room, OT, ICU, Labour room, Laboratory, Dialysis room, CT scan, Radio-imaging etc

Hospital itself

2.SEGREGATION:

• Done at point of generation of waste and put in separate

colored bags. Color coding varies from nation to nation. In

India following color code bags are practiced.

a) Yellow

b) Red

c) Blue/ White Translucent

d) Black

Colour coding and type of container for disposal of bio-

medical waste

Yellow

Plastic Bag

•Human Anatomical

waste (Human tissues, Organs,

Body parts)

•Animal waste

•Microbiology and

biotechnology waste (Cultures, Dishes, Vaccines,

Toxins)

•Solid waste (contaminated with

blood - cotton, dressings

Red Disinfected

container/

Plastic Bag

•Microbiology and

biotechnology waste

(Cultures, Dishes, Vaccines, Toxins)

•Solid waste (Disposable items

Tubings, catheters, IV sets)

•Solid waste (contaminated with

blood - cotton, dressings,

beddings, linen)

Blue/

White transluc

ent

Puncture Proof

container/

Plastic Bag

•Waste sharps (Needles, Syringes,

Scalpels, Blades,

Glass )

•Solid waste (Disposable items

Tubings, catheters,

IV sets)

Black Plastic Bag

•Discarded

medicines and

cytotoxic drugs( outdated,

contaminated and

discarded

medicines )

•Incineration

ash

•Chemicals used

in disinfection

and as

insecticides

3.COLLECTION OF WASTE:

• Centralized sanitation staffs or any other sanitation staffs

should collect the waste during morning, afternoon or evening

under the supervision of nursing staff and sanitation

supervisor; documentation should be done in register

• The garbage bin should be cleaned and disinfected regularly.

4. STORAGE OF WASTE:

• Waste should be stored in separate area, room or building of a

size appropriate to the quantity of waste produced.

5. TRANSPORTATION:

• Wastes should be transported by means of wheeled trolley,

containers or carts making sure that they are not being used for

any other purposes.

LABEL FOR BIO-MEDICAL WASTE CONTAINERS/BAGS

Note : Label shall be non-washable and prominently visible.

HANDLE WITH CARE BIOHAZARD CYTOTOXIC

BIOHAZARD SYMBOL CYTOTOXIC HAZARD SYMBOL

6. TREATMENT & DISPOSAL TECHNOLOGIES:

A. Incineration:- Double chamber pyrolytic incinerators- Single chamber furnaces with static grate- Rotary Kilns

B. Chemical Disinfection:- Formaldehyde-Ethylene oxide- Sodium Hypochlorite-Glutaraldehyde

C. Wet thermal treatment

D. Microwave irradiation

E. Burial

F. Encapsulation

G. Inertization

A. Incineration:

• Incineration is a high temperature dry oxidation process, that

reduces organic and combustible waste to inorganic

incombustible matter and results in a very significant reduction

of waste-volume and weight.

ORGANIC INORGANIC

Matter from a once-living organism

Not consisting of or deriving from living matter

Capable of decay or the product of decay

Able to break down into smaller components

Chemical compounds whose molecules

contain carbon

Chemical compounds that do not contain carbon

BiomedicalWaste Incineration

HeatFlue Gas

Ash

Gas exiting to the atmosphere via a flue (pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator).

• Waste types not to be incinerated are :

(a) Pressurized gas containers.

(b) Large amount of reactive chemical

wastes.

(c) Silver salts and photographic or

radiographic wastes.

(d) Halogenated plastics / Chlorine based

plastics such as PVC

(e) Waste with high mercury or cadmium content, such as broken

thermometers, used batteries.

• Types of incinerators:

1. Double chamber pyrolytic incinerators.

2. Single chamber furnaces with static grate

3. Rotary Kilns

I. Double chamber pyrolytic incinerators:

• Also called as pyrolytic incinerators or controlled air

incineration.

• This is the most common and reliable used process for health

care waste.

• It comprises of two parts:

- Pyrolytic chamber

- A post combustion chamber

PYROLYSIS Chemical reaction that

occurs in the burning of solid organics.

In pyrolysis there is a gas phase present. (wood fire - visible flames -gases released)

flame-less burning of a solid – smouldering - combustion of the solid residue (charcoal) left behind by pyrolysis.

• Firstly, the waste is loaded in to waste bags or containers.

• Then in the pyrolytic chamber the waste is thermally

decomposed by the combustion process leading to solid ashes

and gases formation.Holes in

the grate supplyin

g the primary

combustion air

• Incineration plants must be designed to ensure that the flue gases reach a temperature of at least 850 °C (1,560 °F) for 2 seconds in order to ensure proper breakdown of toxic organic substances. In order to comply with this at all times, it is required to install backup auxiliary burners (often fueled by oil), which are fired into the boiler in case the heating value of the waste becomes too low to reach this temperature alone.

• This process is suitable for:

- Infectious waste (including sharps) and pathological waste.

- Pharmaceutical and chemical residues.

• Inadequate for:

- Non-risk health care waste

- Genotoxic waste

- Radioactive waste

• Drawbacks:

- Requires expensive equipment

- Well trained personnel

II. Single – chamber incinerator

• Used if a pyrolytic incinerator can’t br afforded.

• Treats waste in batches.

• A good fire should first be established on the ground underneath the drum / brick-lined cell.

• Wood should be added to the fire until the waste is completely burnt.

• After burning, the ashes should be collected and buried safely.

• The rotary-kiln incinerator has 2 chambers:

primary chamber:

consists of an inclined refractory lined cylindrical tube. The refractory lining is a protective layer installed inside the kiln or furnace to insulate the furnace steel structure from high temperatures. It also protects it from thermal shocks and chemical attack, and abrasion wears. Movement of the cylinder on its axis facilitates movement of waste.

 Conversion of solid fraction to gases

Secondary chamber:The secondary chamber is necessary to complete gas phase combustion reactions.

CTF or Common Treatment Facilities

The CTFs are responsible for waste

collection and transportation from

the hospitals site, followed by

treatment and destruction as

necessary and finally disposal at the

site of CTF.

2.Chemical disinfection:

• In this process chemicals are added to waste to kill or inactivate

the pathogens.

• This treatment usually results in disinfection rather than

sterilization.

• Chemical disinfection is most suitable for treating liquid waste

such as blood, urine, stools or hospital sewage.

• However, solid wastes including microbiological cultures,

sharps etc. may also be disinfected chemically with certain

limitations.

• Types of disinfectants:

- Formaldehyde

- Glutaraldelhyde

- Sodium hypochlorite

- Ethylene oxide

- Chlorine dioxide

3.Wet Thermal treatment:

• Wet thermal treatment/steam disinfection is based on exposure of

infectious waste to high temperature and high pressure steam

similar to process of autoclaving.

• This process is inappropriate for treating anatomical waste,

chemical and pharmaceutical waste.

Biomedical Waste Autoclave

4. Microwave irradiation:

• Most microorganisms are destroyed by the action of microwave

of a frequency of about 2450 MHz and a wave length of 12.24

nm.

• The water contained within the waste is rapidly heated by the

microwaves and the infectious components are destroyed by heat

conduction.

• But since due to its high operational cost it is not yet

recommended in developing countries.

5. Land Disposal:

• There are two types of disposal land:

(a) Open dumps

(b) Sanitary landfills

• Health-care waste should not be deposited on or around open

dumps.

• Because of the risk of either people or animals coming into

contact with infectious pathogens.

• Sanitary landfills are designed to have many advantages over

open dumps :

(a) Geological isolation of waste from the environment.

(b) Appropriate engineering preparation before the site is ready

to accept waste.

(c) Staff is present on the site to control operations.

Deep Burial Pits for Disposal of Bio-medical waste

6. Inertization:

• The process of "inertization" involves mixing waste with cement

and other substances before disposal, in order to minimize the

risk of toxic substances contained in the wastes migrating into the

surface water or ground water.

• A typical proportion of the mixture is: 65 per cent pharmaceutical

waste, 15 per cent lime, 15 per cent cement and 5 per cent water.

A homogenous mass is formed

(on site) and cubes or pellets are

then transported to suitable

storage sites.

7. Encapsulation:

• This procedure involves filling containers made of high density

polyethylene or metal drums, with waste.

• These containers are then filled up with a medium of

immobilizing material such as cement mortar or clay.

• When the medium has dried, the containers are sealed and

disposed off in a landfill sites.

Advantages:

i. It is a simple, low-cost and safe method

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WASTE CATEGORY TYPE OF WASTE TREATMENT AND

DISPOSAL OPTION

Category No. 1 Human Anatomical Waste (Human tissues, organs, body parts)

Incineration@ / deep burial*

Category No. 2

Animal Waste(Animal tissues, organs, body parts, carcasses, bleeding parts, fluid, blood and experimental animals used in research, waste generated by veterinary hospitals and colleges, discharge from hospitals, animal houses)

Incineration@ / deep burial*

Category No. 3

Microbiology & Biotechnology Waste (Wastes from laboratory cultures, stocks or specimen of live micro organisms or attenuated vaccines, human and animal cell cultures used in research and infectious agents from research and industrial laboratories, wastes from production of biological, toxins and devices used for transfer of cultures)

Local autoclaving/ microwaving / incineration@

CATEGORIES OF BIOMEDICAL WASTE SCHEDULE

69

Category No. 4

Waste Sharps (Needles, syringes, scalpels, blades, glass, etc. that may cause puncture and cuts. This includes both used and unused sharps)

Disinfecting (chemical treatment@@ / autoclaving / microwaving

Category No. 5Discarded Medicine and Cytotoxic drugs (Wastes comprising of outdated, contaminated and discarded medicines)

Incineration@ / destruction and drugs disposal in secured landfills

Category No. 6

Soiled Waste (Items contaminated with body fluids including cotton, dressings, soiled plaster casts, lines, bedding and other materials contaminated with blood.)

Incineration@ / autoclaving / microwaving

Category No. 7

Solid Waste (Waste generated from disposable items other than the waste sharps such as tubing, catheters, intravenous sets, etc.)

Disinfecting by chemical treatment@@ / autoclaving / microwaving

70

Category No. 8

Liquid Waste (Waste generated from the laboratory and washing, cleaning, house keeping and disinfecting activities)

Disinfecting by chemical treatment@@ and discharge into drains

Category No. 9 Incineration Ash (Ash from incineration of any biomedical waste)

Disposal in municipal landfill

Category No.10

Chemical Waste (Chemicals used in production of biological, chemicals used in disinfecting, as insecticides, etc.)

Chemical treatment @@ and discharge into drains for liquids and secured landfill for solids.

Sometimes people just need to sleep!!

..Thanks anyways!