A/HRC/18/31 Parties adopted a guidance paper on hazard characteristic H6.2 (infectious substances), which is intended to assist in determining whether a given waste displays the characteristic to a degree sufficient to render it hazardous.23 68. In practice, the Basel Convention is rarely invoked to ensure the sound management and disposal of hazardous medical waste, since this type of waste is mostly treated within the country where it is generated. B. Stockholm Convention 69. The Stockholm Convention seeks to protect human health and the environment from the harmful impact of persistent organic pollutants. It was adopted on 22 May 2001 and entered into force on 17 May 2004. As at 10 June 2011, 173 parties had adhered to the Convention. 70. Persistent organic pollutants (POPs) are highly hazardous chemical pollutants that remain intact in the environment for long periods, become widely distributed throughout the environment, accumulate in the fatty tissue of living organisms and are found at higher concentrations at higher levels in the food chain. They can be divided into three categories: (a) pesticides; (b) industrial chemicals; and (c) by-products. They are toxic to both humans and wildlife. Specific effects of these pollutants can include cancer, damage to the nervous system, reproductive disorders and disruption to the immune system. 71. Article 5 of the Stockholm Convention requires parties to take all appropriate measures to reduce the unintentional release of the chemicals listed in annex C, with the goal of continuing minimization and, where feasible, their ultimate elimination. The annex applies to dioxins and furans that are unintentionally formed and released from thermal processes as a result of incomplete combustion or chemical reactions. Medical waste incinerators are included in the list of industrial source categories that can result in significant emissions of these chemicals into the environment. Open burning of waste, including burning of landfill sites, is included in the list of other source categories that may generate dioxins and furans. 72. In 2007, at the third meeting of the Conference of the Parties to the Stockholm Convention, participants adopted guidelines on the best available techniques and provisional guidance on best environmental practices relevant to article 5 and annex C to the Convention (decision SC-3/5). According to the guidelines, dioxin emission levels in the air no higher than 0,1 ng/m3 are associated with best available techniques. Under normal operating conditions, emissions lower than this level can be achieved with a welldesigned waste incineration plant equipped with appropriate air pollution control devices. C. World Health Organization 73. WHO has elaborated a number of policy, management and advocacy tools to minimize the risks that the improper management of health-care waste pose to health-care workers, patients, waste handlers, the community at large and the environment, and to facilitate the establishment and sustained maintenance of a sound system of health-care waste management. These include a policy paper on safe health-care waste management (2004)24 and core principles for achieving safe and sustainable management of health-care waste (2007).25 WHO has also developed a handbook on the safe management of health- 23 24 25 16 See UNEP/CHW.7/33, decision VII/17. World Health Organization, Safe health-care waste management (see footnote 5). World Health Organization, WHO core principles (see footnote 8).