A few banned chemicals in pesticides like imazalil are still being used by the U.K., while propiconazole is not.
The EU has published a list of active substances, safeners, and synergists under the EU's pesticide regulations (EC No. 1107/2009), also known as plant protection products (PPPs). The list shows that imazalil is an active substance approved for use until 2024, manufactured and marketed in EU countries. Under the same regulation, propiconazole was approved on June 1, 2004, but this expired on December 19, 2018. Thus, Imazalil is still in use in the EU, while propiconazole is not.
According to the Health and Safety Executive, after Brexit, an independent pesticide regulatory regime took effect in the U.K. on January 1, 2021, meaning new decisions made in relation to existing EU regulations do not apply in the U.K. This includes decisions on active substances, maximum residue levels (MRL), and any new EU PPP legislation. According to the U.K.'s Health and Safety Executive, Imazalil was renewed from December 31, 2021, to December 31, 2024. However, the list does not include propiconazole.
EU PPP legislation continues to apply in Northern Ireland under the Withdrawal Agreement and Northern Ireland Protocol. Furthermore, existing PPP authorizations issued under the EU pesticides regulations remain valid in the U.K. PPPs that have been authorized can be placed on the market and used in the same way as before.