article_snippet: Chlorine was used 100 years ago during the 2nd Battle of Ypres in April 1915, where the gas was vapourised into a cloud.
article_snippet: Chlorine is classified as a 'choking agent', burning the lungs when inhaled in large quantities.
article_snippet: But Chlorine is nowhere near as dangerous as nerve gases like sarin.
article_snippet: Mr de Bretton-Gordon says that chlorine is being used on an 'industrial scale' in Syria and Iraq but that taking simple steps would help people survive an attack.
article_snippet: Chlorine is readily available in Britain, used in swimming pools and decontamination in industry. '
article_snippet: My working with UK charity Syria Relief has focused in Syria on giving civilians the basic know-how to avoid chlorine.
article_snippet: Chlorine is not very toxic and the green and yellow clouds are easy to see and avoid.
article_snippet: Chlorine is very non-persistent only lasting for a few minutes.
article_snippet: Chlorine was used in the First World War but dropped because Chlorine did not work very well. '
article_snippet: Also urinating on a cloth and holding a cloth to your mouth will help because urine kills chlorine. '
article_snippet: I train people in Syria to be aware of which way the wind is blowing because chlorine can travel quickly on the wind, but the wind also means you can avoid the wind. '
article_snippet: Chlorine attacks are very survivable and a lot less dangerous than bombs and bullets, if you use simple procedures.
article_snippet: Jennifer Cole, Senior Research Fellow at defence think-tank Royal United Services Institute, told MailOnline that although chlorine can be lethal, it does appear that it's being used to spread fear by IS.
article_snippet: Jennifer Cole, Senior Research Fellow at defence think-tank Royal United Services Institute said: 'Chlorine is easily available from a number of industrial sources and is very hazardous – causing breathing difficulties in particular and in extreme cases prolonged exposure can kill. '
article_snippet: Chlorine was first used in the First World War and because it is heavier than air the clouds of killer gas would drop into trenches and wipe out troops .
article_snippet: Chlorine was used by the British in the First World War, but Chlorine proved to be unreliable.
article_snippet: Chlorine, a chemical used in industry and water purification process, was first introduced as a chemical weapon at Ypres in World War