What is mustard gas?

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Three people have been arrested by police after stockpile of potentially deadly mustard gas was discovered near Woodhall Spa. The find triggered a major incident, extensive police searches and injured two people – but what is mustard gas, and where has is come from?

Mustard gas, otherwise known as sulphur mustard, is a chemical agent first used in World War One. It can be a potentially lethal substance which causes severe burning and blisters on the skin, eyes, lungs and respiratory tract.

Sulphur mustard was used at war to incapacitate victims in large numbers. It can be absorbed through inhalation or by coming into contact with skin or eyes.

The gas strips away any moisture such as the mucous membranes of the eyes, nose and throat. It causes redness and itching skin that leads to yellow pus-filled blisters.

Early gas masks offered little protection and chemical suits did not come onto the scene until after World War One.

The Geneva Protocol banned the use of poisonous gas as biological weapons in war in 1925.

Roughton Woods has been cordoned off by police since the canisters of gas were found on Sunday, October 1 and investigators have been conducting sweeps of the area, as well as extensive searches of properties in Lincoln and in Woodhall Spa.

The site where the canisters were found was formerly known as RAF Woodhall Spa. The base was opened in February 1942 as a satellite of RAF Coningsby and closed in the mid 1960s.

Lincolnshire Police said they do not believe the incident poses a risk to the public.