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Author: Dr.Sujata.M.Byahatti.

Hospital is one of the complex institutions which are frequently visited by people from every standard of life without any distinction between age, sex, race and religion. Most of these hospitals and health clinics produce a waste which is increasing in its amount and type and leading to risk for patients and personnel who handle these wastes and poses a threat to public health and environment. Keeping in view inappropriate biomedical waste management, the Ministry of Environment and Forests notified the “Biomedical Waste (management and handling) Rules, 1998” in July 1998. In accordance with these Rules, it is the duty of every “occupier” i.e a person who has the control over the institution and or its premises, to take all steps to ensure that waste generated is handled without any adverse effect to human health and environment. The hospitals, nursing homes, clinics, dispensary, animal house, pathological lab etc., are therefore required to set in place where the biological waste treatment facilities are available. It is however not incumbent that every institution and health clinics has to have its own waste treatment facility. However it is incumbent on the occupier to ensure that the waste is treated within a period of 48 hours. The aim of the present article is to enlighten in detail regarding the different types of wastes, the side effects from these wastes and different modalities of their management.


Bio-Medical Waste is any waste generated during the diagnosis, treatment or immunization of human beings or in research activity1. The waste produced in the course of health care activities carries a higher potential for infection and injury than any other type of waste2. Bio-Medical waste generated in the hospital falls under two major Categories – Non Hazardous and Bio Hazardous. Constituents of Non Hazardous waste are Non-infected plastic, cardboard, packaging material, paper etc. Bio hazardous waste again falls into two types (a) Infectious waste- sharps, non sharps, plastics disposables, liquid waste, etc. (b) Non infectious waste-radioactive waste, discarded glass, chemical waste, cytotoxic waste, incinerated waste etc Approximately 75-90% of the Bio-Medical waste is non-hazardous and as harmless as any other municipal waste. The remaining 10-25% is hazardous and can be injurious to humans or animals and deleterious to environment. It is important to realize that if both these types are mixed together then the whole waste becomes harmful3.

Hospital is one of the complex institutions which are frequently visited by people from every standard of life without any distinction between age, sex, race and religion4. The hospital waste, in addition to the risk for patients and personnel who handle these wastes poses a threat to public health and environment5. The hospitals, nursing homes, clinic, dispensary, animal house, pathological lab etc., are therefore required to set in place the biological waste treatment facilities. It is however not incumbent that every institution has to have its own waste treatment facility. The rules also envisage that common facility or any other facilities can be used for waste treatment. However it is incumbent on the occupier to ensure that the waste should be treated within a period of 48 hours.

Bio-Medical Waste Rules, 1998
Keeping in view inappropriate Bio-Medical waste management, the Ministry of Environment and Forests notified the “Bio-Medical Waste (management and handling) Rules, 1998” in July 1998. In accordance with these Rules (Rule 4), it is the duty of every “occupier” i.e. a person who has the control over the institution and or its premises, to take all steps to ensure that waste generated is handled without any adverse effect to human health and environment. Handling, segregation, mutilation, disinfection, storage, transportation and final disposal are vital steps for safe and scientific management of BMW in any establishment3.Schedule I of the Bio-Medical rules contains the categories of Bio-Medical Waste5 (Refer to Table1). Schedule II contains the Colour coding and the type of container for disposal of different Bio Medical waste categories 6. (Refer to Table2).

The classification of health-care waste is summarized in Table 1.

Waste category


Infectious waste
15 per cent

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

Pathological waste
15 per cent

Human tissues or fluids e.g. body parts; blood and other body fluids; fetuses

1 per cent

Sharp waste e.g. needles: infusion sets; scalpels; knives; blades; broken glass

Pharmaceutical waste
3 per cent

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

Genotoxic waste

Waste containing substances with genotoxic properties e.g. waste containing cytostatic drugs (often used in cancer therapy); genotoxic chemicals

Chemical waste

Waste containing chemical substances e.g. laboratory reagents; film developer; disinfectants that are expired or no longer needed; solvents

Wastes with the high content of heavy chemicals

Batteries; broken thermometers; blood -pressure
gauges; etc.

Pressurized containers

Gas cylinders: gas cartridges.
aerosol cans

Radioactive waste
< than 1percent

Waste containing radioactive substances e.g. unused liquids from radiotherapy or laboratory research; contaminated glassware, packages, or absorbent paper; urine and excreta from patients treated or tested with unsealed radionuclides; sealed sources

(Courtesy: Park K editor. Park’s textbook of preventive and social medicine, 18th edition.)

Table 2. Colour coding and type of container for disposal of biomedical waste.

Colour coding

Type of container

Waste category

Treatment options


Plastic bag

Cat. 1, Cat. 2, and Cat.3,Cat.6

Incineration/deep burial


Disinfected container/ plastic bag

Cat. 3, Cat. 6, Cat. 7

Autoclaving/Microwaving/Chemical Treatment

Blue / White translucent

Plastic bag/puncture proof container

Cat. 4 and Cat. 7

Autoclaving/Microwaving/Chemical Treatment and Destruction/Shredding


Plastic bag

Cat. 5 and Cat. 9 and Cat. 10 (solid)

Disposal in secured landfill

(Courtesy: Park K editor. Park’s textbook of preventive and social medicine, 18th edition.)

Bio-Medical Waste: Management Issues
A major issue related to current Bio-Medical waste management in many hospitals is that the implementation of Bio-Waste regulation is unsatisfactory as some hospitals are disposing of waste in a haphazard, improper and indiscriminate manner. Lack of segregation practices, results in mixing of hospital wastes with general waste making the whole waste stream hazardous. Inappropriate segregation ultimately results in an incorrect method of waste disposal. A bag not securely tied results in scattering of Bio-Medical waste. Bio-Medical waste scattered in and around hospitals invites flies, insects, rodents, cats and dogs that are responsible for spread of communicable diseases like plague and rabies. Most importantly there is no mechanism to ensure that all waste collected and segregated, reaches its final destination without any pilferage. Additional hazard includes recycling of disposables without even being washed7.

Biomedical Waste Management Process
Handling, segregation, mutilation, disinfection, storage, transportation and final disposal are vital steps for safe and scientific management of biomedial waste in any8,9. The key to minimization and effective management of biomedical waste is segregation (separation) and identification of the waste. The most appropriate way of identifying the categories of biomedical waste is by sorting the waste into colour coded plastic bags or containers. Biomedical waste should be segregated into containers/ bags at the point of generation in accordance with Schedule II of Biomedical Waste (management and handling) Rules 1998 as given in Table 1.

General waste like garbage, garden refuse etc. should join the stream of domestic refuse. Sharps should be collected in puncture proof containers. Bags and containers for infectious waste should be marked with Biohazard symbol. Highly infectious waste should be sterilized by autoclaving. Cytotoxic wastes are to be collected in leak proof containers clearly labelled as cytotoxic waste 8. Needles and syringes should be destroyed with the help of needle destroyer and syringe cutters provided at the point of generation. Infusion sets, bottles and gloves should be cut with curved scissors. Disinfection of sharps, soiled linen, plastic and rubber goods is to be achieved at point of generation by usage of sodium hypochlorite with minimum contact of 1 hour. Fresh solution should be made in each shift. On site collection requires staff to close the waste bags when they are three quarters full either by tying the neck or by sealing the bag. Kerb side storage area needs to be impermeable and hard standing with good drainage. It should provide an easy access to waste collection vehicle9.
Biomedical waste should be transported within the hospital by means of wheeled trolleys, containers or carts that are not used for any other purpose. The trolleys have to be cleaned daily. Off site transportation vehicle should be marked with the name and address of carrier. Biohazard symbol should be painted. Suitable system for securing the load during transport should be ensured. Such a vehicle should be easily cleanable with rounded corners. All disposable plastic should be subjected to shredding before disposing off to vendor. Final treatment of biomedical waste can be done by technologies like incineration, autoclave, hydroclave or microwave9.

Common Regional Facility For Final Disposal of Infectious BMW
Hospitals, private practitioners, emergency care centers though aware of the rules do not have the time or resources to arrange satisfactory disposal of biomedical waste. Self contained on site treatment methods may be desirable and feasible for large healthcare facilities10. They will not be practical or economical for smaller institutes. An acceptable common system should be in place which will provide free supply of colour coded bags, daily collection of infectious waste, safe transportation of waste to off site treatment facility and final disposal with suitable technology.
Every hospital generating Bio-Medical waste needs to set up requisite Bio-Medical waste treatment facilities to ensure proper treatment of waste. As per the guidelines no untreated Bio-Medical waste is to be kept stored beyond a period of 48 hours. The BMWM module handles all aspects related to fuel filling, complaints lodging, etc of the Waste disposal equipments for ensuring smooth functioning of the Bio-Medical waste treatment facilities. The module is also able to generate alerts under exceptional conditions such as waste not treated with in stipulated time10.

Cost of Biomedical Waste Management

The cost of construction, operation and maintenance of system for managing biomedical waste represents a significant part of overall budget of a hospital if the BMW handling rules 1998 have to be implemented in their true spirit. Govt of India in its pilot project for hospital waste management in Govt hospitals has estimated Rs.85 lakh as capital cost in 1000 bedded super speciality teaching hospital which includes on site final disposal of BMW. Two types of costs are required to be incurred by hospitals for BMW management, internal and external. Internal cost is the cost for segregation, mutilation, disinfection, internal storage and transportation including hidden cost of protective equipment. External cost involves off site transport of waste, treatment and final disposal 11.

Dental Waste Management
Currently, it has been estimated that dentists contribute between 3% and 70% 12-16 of the total mercury load entering wastewater treatment facilities. Practitioners are encouraged to follow “best management practices” in the handling and disposal of dental amalgam 17-21 to limit its potential environmental effects. Best management practices apply to a variety of hazardous wastes and depend on the type of waste in question. They are designed to provide guidelines to practitioners to limit the occupational and environmental hazards of a particular substance17. Practitioners are advised to use precapsulated dental amalgam to reduce the risk of liquid mercury spill or clinic–environmental contamination. Alternative restorative materials (i.e., composite resin, ceramic or other metal alloys) can be used, when indicated. Limiting the amount of dental amalgam triturated for a procedure also reduces the amount of waste generated17-21. Practitioners are legally responsible for the collection, storage and disposal of both gross debris and fine amalgam particles removed via high-volume suction22-25. Chair-side traps have been found to be approximately 68% effective in their removal of amalgam particles from dental wastewater, while the average vacuum filter is approximately 40% effective26. Dental amalgam scrap as well as amalgam waste gathered by filters and separation devices should be collected periodically and stored in a labelled, leak-proof container 13,19,22 (e.g., in a dry mercury-vapour suppressant system27). The proper storage of dental amalgam will also reduce the amount of elemental mercury vapour that enters the work environment. As dental practitioners, we are responsible for ensuring that the waste carriers we use are registered and qualified to handle the wastes we produce. Regardless of the means of disposal of dental amalgam, practitioners should not flush contaminated wastewater down sinks, rinse chair-side traps or vacuum filters in sinks, nor place material containing dental amalgam in general garbage or waste to be incinerated12,13,18,22,28,29,30,31. These practices release mercury into the environment and negate the profession’s efforts to reduce environmental mercury contamination. Several reports outline these considerations and list the questions that should be posed when selecting a unit for a particular dental office17,19,32.

Amalgam Separators
Separation technology is based on sedimentation, filtration or centrifugation of the dental amalgam particles from wastewater12,13,17,26,31,32,33. The proper amalgam separation unit must be selected carefully as not all units are able to work efficiently in every physical arrangement32,34. Some units are placed before vacuum pumps, others after. Some require considerable space to house the unit, while others are compact. Costs of the device include not only the purchase price and installation costs, but also the cost of maintenance, replacement of filters and canisters and waste disposal19,32.


Silver is another heavy metal that can enter our water system via improper disposal of dental office waste. Although silver is a component of dental amalgam, the silver thiosulfate in radiographic fixer (a solution normally used in the processing of dental radiographs) presents a greater environmental concern 13,19. Some forms of silver are more toxic than others; for example, silver thiosulfate is less toxic than free silver ions13,19. Again, limits for silver concentration in wastewater are set by individual municipalities and jurisdictions and can be obtained through local environment authorities. Used radiographic fixer must not be washed down the drain. The best way to manage silver waste is through recovery and recycling. Dentists can install in-house silver recovery units to salvage the silver themselves, allowing for some monetary return on the equipment investment when the silver is later sold. 13,19. These units generally recover silver ions from the waste solution through displacement of iron ions or through a closed-loop electrolytic system that recovers not only silver for reuse, but also the radiographic fixer. Alternatively, the waste can be collected by a registered agency certified to carry and manage the waste13,19,35. Another common waste product in the dental office, unused film should also not be placed in the general waste. Unused films contain unreacted silver that can be toxic in the environment. Safe disposal can generally be accomplished by simply contacting the supplier of the product and returning the waste for recycling. Alternatively, a certified waste carrier can be contacted to dispose of the waste, ideally by recycling13,19. With recent advances in radiographic technology, digital imaging is becoming a popular means of obtaining dental radiographs. Among its advantages are reduced radiation exposure and the absence of chemical image processing13. Therefore, incorporation of digital imaging within the dental office can greatly reduce the amount of silver waste generated.


An additional by product of traditional radiography is the lead shields contained in each film packet. Although the lead shields themselves are relatively small, the cumulative waste produced can be considerable36. An added benefit of digital radiography is the reduction in lead waste production. Lead, like mercury and silver, is toxic and persists in the environment13,36. Even at low levels of exposure, lead exerts adverse health effects on both children 37,38. and adults39,40. Reducing environmental lead contamination by dental practitioners is an inexpensive and easy task13,36. The lead shields from film packets merely have to be collected and returned periodically to the manufacturer for recycling13,19,36. The only cost is for postage. Unfortunately, some manufacturing companies report that only about 5% of products sold are returned. In part, it appears that this is due to a lack of awareness of the offered service36.

Biomedical Waste

Biomedical waste encompasses materials capable of causing disease or suspected of harbouring pathogenic organisms60; it includes blood-soaked gauze, tissues and syringes, 41,42. although not extracted teeth. Non-sharp biomedical waste products should be stored in a yellow bag that is properly labelled with a biohazard symbol. Sharps (i.e., syringes, suture needles) should not be included in the bagged general or biomedical waste, but should be stored in a puncture-resistant, leak-proof, properly labelled container until collection and incineration19. Currently, Canadian guidelines 42,43 for the storage and management of biomedical wastes are under revision. These practices can be modified by provincial and territorial governments and municipalities; therefore, it is best to contact local environment and waste transport authorities to ensure that proper procedures and regulations are followed within each jurisdiction.

General Office Waste
Purchase of products with minimal packaging and use of reusable plastic containers (e.g., for cleaning and disinfecting solutions) can reduce general waste production19. Products made from recycled or partly recycled materials can also be used (e.g., cotton or wool rolls, paper towels) 13,19. Energy efficient lighting and temperature regulation can limit office energy use. Single-spaced printing and use of both sides of pages can decrease the amount of paper used in the dental office13.

Used X-ray fixer: Collect and store used fixer in a closed plastic container labeled with the words, “Hazardous Waste-Used Fixer,” and the date that the fixer was first added. When enough fixer has accumulated (usually 5-10 gallons), contact a recycling service to pick-up the used fixer. These service companies will reclaim the silver present in the used fixer. Do not mix fixer and developer. The other option for disposing of used X-ray fixer is to install a silver recovery unit at the end of the X-ray processing unit. The recovered silver can be sold to a metal reclaimer, and the treated fixer can be disposed of down a drain. However, if you are connected to a septic system, do not dispose of treated fixer down a drain. It is important to note that the silver recovery unit must be designed to handle small quantities of fixer waste. Most units are designed to handle larger and continuous quantities of waste. Be sure to follow the proper equipment operating and maintenance procedures. However, if there is a connection to a septic system, do not dispose of this waste water down a drain44.
X-ray film: Silver can be reclaimed from X-ray film. Reclamation companies that accept used fixer will often take X-ray film as well. Label the container as hazardous waste.
Lead foil: Reclamation companies that accept used fixer also may accept lead foil. Another possible outlet for recycling lead foil is through your dental supply company. Label the container as hazardous waste44.
Amalgam: These particles are a possible source of mercury in the sewer system. Amalgam particles should be captured on screens or in traps and recycled. Store waste amalgam in a closed container that is labeled as hazardous waste and list the contents and the date. Used and empty amalgam capsules may be disposed of as solid waste since they are nonhazardous.

Managing Other Wastes:
Blood: Swabs or dressings that are dripping blood are regulated by infectious waste rules. Those materials that contain only small quantities of blood may be placed in the garbage.
Sharps: Scalpels, needles and other sharp objects that could puncture the skin are regulated by infectious waste rules. These materials must be placed in a puncture proof container, labeled as used sharps and properly disposed of by a medical waste service.
Developer: Used developer can be disposed of down a drain (sewered) that is connected to a publicly owned treatment works.
Cleaners for developer systems: If cleaners contain chromium, they MUST be manifested and disposed of as hazardous waste. It may be easier and cheaper to use cleaners that do not contain chromium. Or, find a cleaning service that will clean the developing unit at your clinic and properly dispose of the chromium-containing cleaner44.
Vapor sterilizer chemicals: If it is necessary to dispose of small quantities of these chemicals, see if the sewage treatment system can handle the amount you have. If not, these chemicals must be disposed of as hazardous waste.
Traps and Filters: First, disinfect a disposable trap by soaking it for 24 hours in a minimum amount of disinfectant. Then, remove all visible amalgam and store it in a dry, covered container. Wear a mask and gloves during this process. The disinfected trap then should be autoclaved and disposed of as solid waste. If it is not autoclaved, it must be disposed of as infectious waste.
Reusable traps: Like the disposable traps, first disinfect a reusable trap by soaking it for 24 hours in a minimum amount of disinfectant. Then remove all visible amalgam and store it in a dry, covered container. Wear a mask and gloves during this process. The disinfected trap then should be autoclaved. After autoclaving, dispose of the contents as solid waste and reuse the trap44.
Secondary filters: Change these filters at least once a month, or more frequently if needed. Do not dispose of as infectious waste. As of the date of this printing, these filters can be disposed of as solid waste; however, this is subject to change44.

  1. Govt of India, Ministry of Environment and Forests Gazette notification No 460 dated July 27, New Delhi: 1998:10-20
  2. Park K. Hospital Waste Management. Park’s Textbook of Preventive and Social Medicine. M/s Banarasidas Bhanot Publications, New Delhi. 18th Edn, 2005: 595-598.
  3. Virendar Pal Singh, Gautam Biswas, Jag Jiv Sharma. Biomedical Waste Management - An Emerging Concern in Indian Hospitals. 2007-07 - 2007-12) Vol. 1, No. 1 (.http://www.indmedica.com/journals.php?journalid=11&issueid=98&articleid=1324&action=article.
  4. Rao SKM, Garg RK. A study of Hospital Waste Disposal System in Service Hospital. Journal of Academy of Hospital Administration July 1994; 6(2):27-31.
  5. Singh IB, Sarma RK. Hospital Waste Disposal System and Technology. Journal of Academy of Hospital Administration, July 1996;8(2):44-8.
  6. Website of the MINISTRY OF ENVIRONMENT & FORESTS. Last accessed on 6th February 2009.
  7. National AIDS Control Organization. Manual of Hospital infection control, New Delhi, 1998; 50-66.
  8. Acharya DB, Singh M. The book of Hospital Waste Management. Minerva Press, New Delhi 2000;15:47.
  9. Srivastava JN. Hospital Waste Management project at Command Hospital, Air Force, Bangalore. National Seminar on Hospital waste Management: A report 27 May 2000.
  10. Priti Razdan, Amarjeet Singh Cheema Bio-Medical Waste Management System. Proceedings of ASCNT – 2009, CDAC, Noida, India, pp. 26 – 31.
  11. A study of Hospital Waste Management System in Command Hospital (Southern Command), Pune; A dissertation submitted to University of Pune. WG CDR RK Ranyal Dec 2001; page 37.
  12. Chin G, Chong A, Kluczewska A, Lau A, Gorjy S, Tennant M. The environmental effects of dental amalgam. Aust Dent J 2000; 45(4):246–9.
  13. Anderson K. Creating an environmentally friendly dental practice. CDS Rev 1999; p. 12–18.
  14. Jones DW. Putting dental mercury pollution into perspective. Br Dent J 2004; 197(4):175–7.

More References are available on request