For more than 100 years chemical weapons have terrorised, maimed and killed soldiers and civilians alike. As a chemist, the part his profession has played in the development of these weapons has long concerned Andrea Sella, professor of chemistry at University College London.

In this programme he examines the motivation of chemists like Dr Fritz Haber, who first encouraged the German military to deploy chlorine gas in World War One for the sake of “The Fatherland” and of Dr Gerhard Schrader, who, in his hunt for an effective pesticide, accidentally discovered a new class of lethal nerve agents for Nazi Germany.

From chlorine, phosgene and the mustard gases, to tabun, sarin, soman, VX and the novichok agents used to target former Soviet agent Sergei Skipal in England, Andrea weaves archive with interviews with key figures in the ongoing campaign to control and ban the use of such weapons and he asks how science educators can prepare young chemists for the moral hazard posed by this particular class of weapon.

(Photo: Mock up of Novichok agent (A-234), Credit: WoodyAlec/Getty Images)