Waste generated in medical establishments such as hospitals, clinics, pathological and medical research laboratories has three major components:

• ordinary refuse (e.g. refuse from administrative offices, kitchen waste);
• chemical waste (e.g. some used/expired drugs or chemicals);
• clinical waste (e.g. pathogenic or infectious waste, used or contaminated sharps).

Clinical waste is defined under the Waste Disposal (Amendment) Ordinance 2006 as waste consisting of any substance, matter or thing belonging to any of the following 6 groups that is generated in connection with -

• a dental, medical, nursing or veterinary practice;
• any other practice, or establishment that provides medical care or services for the sick, injured, infirm or those who require medical treatment;
• dental, medical, nursing, veterinary, pathological or pharmaceutical research; or
• a dental, medical, veterinary, or pathological laboratory practice.

• Group 1 - Used or Contaminated Sharps
  Syringes, needles, cartridges, ampoules and other sharp instruments which have been used or which have become contaminated with any other group of clinical waste.
• Group 2 - Laboratory Waste
  Unsterilized laboratory stock cultures, or cultures of infectious agents and potentially infectious waste with significant health risk from dental, medical, veterinary or pathological laboratories.
• Group 3 - Human and Animal Tissues
  All human and animal tissues, organs and body parts as well as dead animals, but excluding dead animals, animal tissues, organs and body parts arising from a veterinary practice or a Chinese medicine practice, and teeth arising from a dental practice.
• Group 4 - Infectious Materials
  Infectious materials from patients with the following pathogens: Crimean/Congo hemorrhagic fever, Ebola, Guanarito, Hendra, Herpesvirus simiae (B virus), Junin, Kyasanur forest disease, Lassa fever, Machupo, Marburg, Nipah, Omsk, Russian spring-summer encephalitis, Sabia and Variola viruses, and Severe Acute Respiratory Syndrome Coronavirus. Any materials contaminated by the above infectious materials are also classified as Group 4 waste.
• Group 5 - Dressings
  Surgical dressings, swabs and all other waste dribbling with blood, caked with blood or containing free-flowing blood.
• Group 6 - Other Wastes
  Such other wastes as specified by the Director of Environmental Protection by notice published in the Gazette if in his opinion such wastes are likely to be contaminated with infectious materials from patients falling within such case definition as specified in the notice and may pose a significant health risk.

Based on a survey conducted in 1999, the generation rate of clinical waste in public hospitals is 0.12 kg/bed/day, which is much lower than the rates of 5.5, 2.2 and 0.6 kg/bed/day of clinical waste in UK, USA and the Netherlands respectively. It is estimated that about 7 to 8 tonnes of clinical waste are produced in Hong Kong daily. [Source: Proceedings of the ISWA International Symposium & Exhibition on Waste Management in Asian Cities, Vol. 1, pp. 84-89.]

The majority of clinical waste generated in Hong Kong is disposed of in special pre-excavated trenches at the landfills. The disposal of clinical waste at the landfills is an interim arrangement and is not the best environmental option, since the infectious agents and residual amount of cytotoxic drugs still remain in the waste.

Besides, a small amount of clinical waste consisting of human tissues and amputated organs are incinerated at the four pathological incinerators at the Tuen Mun Hospital and Yan Chai Hospital. These incineration facilities are expected to stop handling clinical waste when the clinical waste control legislation is in place.

Clinical waste is potentially dangerous either because of its infectious nature or its potential to cause injury through the presence of sharps such as needles. Based on the US statistics, about 15% or less of the overall waste from medical establishment is infectious.

The present co-disposal of clinical waste and municipal solid waste in landfills is not the best environmental option. The infectious agents and residual amount of cytotoxic drugs present in the waste might pose a hazard to the environment and to those who come in contact with the waste.

The Waste Disposal Ordinance has been amended in March 2006 to introduce the framework for controlling the collection and disposal of clinical waste by means of licence. More specific controls, which will be introduced through the subsidiary regulation, will set out the requirement for clinical waste producers to arrange for delivery of their waste by a licensed collector to a licensed facility for proper disposal. The legislative control will be complemented by Codes of Practice to provide guidance on the proper management of clinical waste.

At present, waste producers are free to engage the services of any waste collectors. Either the waste producer or collector has to obtain a Clinical Waste Disposal Permit from the EPD if he wishes to dispose of clinical waste at landfills. The EPD maintains a list of commercial clinical waste collectors for reference by the public. The list is compiled based on the latest information available to the department but it does not constitute any recommendation by the department.

• Thermal treatment technologies
  High-temperature incineration is the predominant and most well proven technology adopted in Europe, Australia and the Asian regions. Other thermal treatment technologies include pyrolysis and gasification in which wastes are heated in the presence of little or no oxygen. Pyrolysis is a relatively new technology which has only limited application in clinical waste treatment at present.
  
  
• Alternative and other novel treatment technologies
  Alternative treatment technologies broadly include microwave treatment, autoclaving and some proprietary chemical disinfection technologies, which are becoming more common in the U.S. and some European countries in recent years. Novel treatment technologies include plasma based systems and irradiation. However, clinical waste after treatment by alternative technologies and irradiation still requires ultimate disposal or incineration to dispose of the residual amounts of cytotoxic drugs that may be present in the clinical waste.
  

Q8.

The Government has engaged an international expert on clinical waste management to evaluate the available treatment technologies worldwide, and advise on the application of such technologies in Hong Kong, with due reference to practices adopted by other developed countries. The review has examined a number of technologies, including chemical disinfection, thermal treatment and novel technologies.

The review indicated that alternative technologies cannot properly handle all kinds of clinical waste generated in Hong Kong and would require stringent segregation to separate residual chemicals and drugs from the waste prior to treatment. Most of the alternative technologies require shredding which may pose occupational health hazards to workers. Moreover, residual chemicals and volatile organic compounds in the clinical waste that cannot be destroyed under low temperature will enter into the environment as aerial emission.

The review compares the alternative technologies with the proven technology of high temperature incineration based on various considerations : health, safety and environmental impacts, efficacy in killing infectious microorganisms, reliability and ease of maintenance, weight and volume reduction of waste, handling of residues and further treatment requirement, space requirement, public perception of risk, as well as their costs and financial implications. The review findings conclude that alternative treatment technology is not the most effective arrangement for local application at the moment.

Since the Chemical Waste Treatment Centre (CWTC) has a high temperature incinerator which is fully equipped with advanced pollution abatement devices, the review recommended that it should be modified to treat clinical waste. The Government has consulted with the Advisory Council for the Environment, the Legislative Council and various stakeholders on the review findings. To complement the legislative control, the CWTC will be modified to treat clinical waste in accordance with the new disposal arrangement. At the same time, the Government will continue to monitor the development of alternative treatment technologies for clinical waste, since some of the technologies may have potential for local application in the longer term.