About Healthcare Waste Treatment

This page discusses healthcare waste treatment processes used for reducing potential hazards to public health and the environment.

Healthcare Waste, and Why it Needs Treatment.

Health care waste is a by-product of health care. It includes sharps, non-sharp blood contaminated items, blood, body parts and tissues, chemicals, pharmaceuticals and radioactive materials. Poor management of health care waste exposes health care workers, waste handlers, patients, families and the greater community to preventable infections, toxic effects and injuries.

Health-care waste contains potentially harmful microorganisms that can infect hospital patients, health workers and the general public. Other potential hazards may include drug-resistant microorganisms which spread from health facilities into the environment.

Effect of Exposure to HCW through improper management

Clinical Waste Exposure

According to the “Conclusion of the United Nations Special Rapporteur, July 2011”, improper management and disposal of medical waste is a threat to the enjoyment of human rights, including the rights to:

  • ✓ Life,
  • ✓ Highest attainable standard of physical and mental health,
  • ✓ Safe and healthy working conditions,
  • ✓ Adequate standard of living.

Those affected include medical staff, patients, support service workers, waste workers, recyclers, scavengers and the public.

Infectious waste should always be assumed to contain pathogenic microorganisms. This poses a severe risk for the environment and the population with different pathogenic ways of transmission for different types of diseases.

Safe management of health care waste involves five guiding principles:

  1. Reduce the potential hazard posed by healthcare waste in order to protect public health and the environment.
  2. Treatment of health-care waste should be considered in the context of the waste management hierarchy.
  3. Take measures to minimise wastes. Segregate and reuse non-infectious waste items wherever possible.
  4. Following minimisation, treat the remaining waste materials to reduce the health and environmental hazards,
  5. Proper disposal of residues.

Approaches to Healthcare Waste Treatment

1. On-site Treatment of Healthcare Waste:

Healthcare facility treats it's own waste.

2. Cluster Treatment of Healthcare Waste:

Hospital treats own waste plus the infectious waste from other healthcare facilities in the immediate local community.

3. Central Treatment of Healthcare Waste:

Dedicated treatment plant that provides collection and treatment of clinical waste from many health centres and medical facilities within an urban centre.

Health Care Waste Treatment Processes

Treatment Processes

Thermal Heat Treatment

Thermal heat treatment processes use heat generated, thermal energy to destroy pathogens in the waste. Heat based processes are used in most treatment facilities around the world.

Depending on the temperature used, this category is further subdivided into low-heat (operating between 100°C and 180°C ) and high-heat (operating above 180°C.) variants of the process.

  • High heat thermal processes use combustion and/or pyrolysis; or
  • Low heat thermal processes, also known as non-burn or non-incineration treatment technologies.
Chemical Treatment Processes

Chemical treatment of infectious healthcare waste typically uses chemical disinfectants such as dissolved chlorine dioxide, bleach (sodium hypochlorite), peracetic acid, lime solution, ozone gas, or dry inorganic chemicals.

  • Often involves shredding, grinding, or mixing to increase exposure of waste to the chemical agent.
  • Treatment usually results in disinfection rather than sterilisation.
  • For liquid systems, wastes may go through a dewatering stage to remove and recycle the disinfectant.
Irradiation Treatment Process

  • Uses irradiation from electron beams, Cobalt-60, or ultraviolet sources to destroy pathogens.
  • Effectiveness of pathogen destruction depends on absorbed dose by mass of waste.
  • Requires shielding to prevent occupational exposures.
  • Not widely used for treating healthcare waste due to the high investment cost.
Biological Treatment Process

Specifically refers to the degradation of organic matter through processes occurring in nature. Examples include composting, vermiculture, bio-digestion, and natural decomposition through burial of cadavers, tissues and anatomical parts.

  • Some technologies add enzymes to speed up decomposition of organic waste.
  • Composting and vermiculture have been successfully used for placenta and hospital kitchen waste.
Mechanical Processes

Mechanical Treatment processes generally supplement other treatment methods.

  • Includes shredding, grinding, mixing, and compaction which reduce waste volume, but are unable to destroy pathogens
  • Shredders and mixers can improve rate of heat transfer and expose more surface area of wastes for treatment
  • Mechanical methods should not be utilised before the waste is disinfected (unless the mechanical process is part of a closed system that disinfects air before it is released to the surrounding environment)
  • Workers could be at an increased risk of exposure to pathogens in the air if infectious waste is shredded or mixed in an open system before treatment