A/HRC/18/31 7. The remaining 20 to 25 per cent of health-care waste includes that part of the healthcare waste that is generated as a result of patient diagnosis, treatment or immunization. It is regarded as hazardous and may create a variety of health risks if not managed and disposed of in an appropriate manner. Hazardous medical waste may be classified into different types of waste according to the source, type and risk factors associated with its handling, storage, transport and ultimate disposal. These include (a) infectious health-care waste; (b) sharps; (c) anatomical and pathological waste; (d) chemical and pharmaceutical waste; and (e) radioactive waste. 8. Infectious health-care waste includes all biomedical and health-care waste, such as discarded materials or equipment contaminated with blood and other body fluids, contaminated waste from patients known to have blood-borne infections, and laboratory waste, which has the potential of transmitting infectious agents to humans or animals. Infectious waste constitutes from 15 to 20 per cent of all health-care waste. It must either be incinerated or be disinfected prior to final disposal through non-burn technologies, such as autoclaving and microwave treatment.2 Incineration is the method most commonly used in developing countries to dispose of infectious waste. 9. Sharps include needles, syringes, blades, scalpels and other discarded objects with sharp or pointed parts able to cause injury. Since they can pierce the skin and are often contaminated with blood or other body fluids of patients with hazardous communicable diseases, sharps must be categorized as infectious waste. Sharps constitute approximately 1 per cent of all health-care waste. In order to prevent needle-stick injuries, used syringes and needles must be collected in puncture-resistant plastic containers. Treatment options include steam, heat or chemical disinfection, burial in a concrete pit on the health-care premises or incineration at a high temperature and with appropriate air pollution control to ensure minimal emission of toxic gases. Needles can be separated from the plastic syringe with a needle remover or cutter and placed in puncture-proof plastic or metal boxes for disposal in a sharps pit or other controlled on-site burial location. 10. Pathological waste is waste containing pathogens that could cause disease to humans and animals. It includes blood, mucus and anatomical parts or tissues removed during surgery or autopsy, as well as other materials, such as laboratory cultures and stocks requiring special handling and disposal procedures. Anatomical waste is a subgroup of pathological waste and consists of human body parts, including amputated body parts and other anatomical waste that is recognizable by the public or health-care staff and that demand, for ethical reasons, special disposal requirements. Anatomical and pathological waste represents 1 per cent of total health-care waste, and is always treated as potential infectious waste for precautionary reasons. In many countries, this waste is incinerated, but non-technologies can also be applied. Infectious laboratory waste should be autoclaved at the point of generation to reduce its hazardousness. 11. Chemical waste includes discarded chemicals that are generated during disinfecting procedures or cleaning processes. Pharmaceutical waste consists of expired, unused, spilt and contaminated pharmaceutical products, drugs and vaccines, as well as discarded items used in the handling of pharmaceuticals (such as bottles or vials). Waste in this category includes a multitude of preparations ranging from pharmaceuticals and cleaning agents not posing any risk to human health and the environment to disinfectants containing heavy metals and specific medicines containing a large variety of hazardous substances. Chemical and pharmaceutical waste constitutes 3 per cent of all medical waste. It should be disposed of in an appropriate waste disposal facility, according to the risk it poses. Whenever 2 Non-burn technologies employ heat to destroy disease-causing micro-organisms in waste. These technologies operate at temperatures that are high enough to kill micro-organisms but insufficient to cause combustion, thereby avoiding the creation of toxic by-products, like dioxins. Chemical and biological processes can also be used to digest tissue, pathological waste and anatomical parts. 5