They were designed as part of a Soviet programme codenamed '' ' FOLIANT ' '' . Five Novichok variants are believed to have been adapted for military use . The most versatile is A-232 ( Novichok-5 ) . Novichok agents have never been used on the battlefield . The UK government determined that a novichok agent was used in the poisoning of Sergei and Yulia Skripal in Salisbury , Wiltshire , England in March 2018 . It was unanimously confirmed by four laboratories around the world , according to the Organisation for the Prohibition of Chemical Weapons ( OPCW ) . Novichok was also involved in the poisoning of a British couple in Amesbury , Wiltshire , four months later , believed to have been discarded after the Salisbury attack . The attacks led to the death of one person , left three others in a critical condition from which they recovered , and briefly hospitalised a police officer . Russia denies producing or researching agents " under the title Novichok "
poisoning of a British couple
2018 Amesbury poisonings
Novichok agent