THE HAGUE, Netherlands (AP) — Member states of the global chemical weapons watchdog have agreed to update their list of banned substances for the first time by adding the nerve agent used in the attempted assassination last year of a former Russian double agent.

The decision Wednesday to add Novichok nerve agents to the Chemical Weapons Convention was reached by consensus at the annual meeting of the 193 member states of the Organization for the Prohibition of Chemical Weapons.

Novichok joins agents including sarin, ricin and sulfur mustard on the convention’s so-called Schedule 1 of banned substances.

The convention, which outlaws the production and use of chemical weapons, came into force in 1997.