The image that many have of chemical warfare is one of mud encrusted soldiers, eyes bandaged, with one arm on the shoulder of the man in front, and all being led to what we hope is a first-aid station, en route to hospital. It is an enduring image and one that conveys something of the horror of chemical warfare. In the First World War attacks with chemicals caused about 1.3 million casualties of whom some 90,000 died fairly soon after their exposure. Many more will have died later on but their deaths will not have been attributed to chemical warfare.

Gas attacks started in 1915 with chlorine. As the war progressed different chemical agents were added to the inventory of those used. Today there are a whole range of chemical warfare agents which cause a wide range of symptoms and soldiers now have extremely sophisticated protective clothing and gas masks to protect them. Most hope that they will never have to wear these because chemical warfare is outlawed by international law. But from 1914 to 1918 , and even after this, there were many, both scientists and politicians , who argued that chemical warfare agents were less destructive than bombs and bullets. Some hoped that chemical warfare use might shorten wars and reduce casualties.

With advances in science offering opportunities to devise ever more sophisticated chemical agents with very precise effects on humans voices are again to be heard arguing that chemical warfare can be beneficial. Are they right?

Alastair Hay is Professor of Environmental Toxicology at the University of Leeds. He has worked on issues relating to chemical and biological warfare ( CBW ) for some 30 years. Much of his work has dealt with the need for workable, international treaties which outlaw the use of CBW. Professor Hay has been involved in field expeditions in Iraq and Bosnia to investigate the use of chemical warfare agents. He has written extensively on the subject and helped prepare the World Health Organisation’s 2004 manual ‘Public health response to biological and chemical agents’. Currently Professor Hay chairs a small international working group which is preparing educational material for chemists on multiple uses of chemicals, chemical warfare agents and codes of conduct.