In 1999 the Conference of the Parties to the Basel Convention adopted the Technical Guidelines on Physico-Chemical Treatment (D9)/Biological Treatment (D8) available in the following page.
Following the OEWG-12 meeting, online segment in 2020 Parties and Observers were invited to provide comments on whether the Technical Guidelines on Physico-Chemical Treatment (D9)/Biological Treatment (D8) should be updated by 30 November 2020. No comments were received to that effect.