Bombs laced with chlorine, which is available to buy in large quantities in Britain, has become the "chemical weapon of choice" for IS fighters, security experts warned.
Colonel Hamish de Bretton-Gordon, a leading expert on chemical warfare, has called on the British government to tighten controls on chlorine sales in Britain.
"As more jihadists return to this country there is a growing chance (of a chlorine bomb attack). That to me puts it through the threshold where we should look into this seriously," he was quoted as saying by The Times newspaper.
An improvised chlorine bomb would cause carnage if detonated on the London Underground network, on the mainline railway network or in a shopping centre.
The chlorine that is often used in bombs in Iraq comes from the cylinders on the back of household fridges.
Militants strip off the steel bottle and attach an explosive charge to make a simple improvised chlorine device - something that could be repeated in Britain.
"Somebody could go to a waste site where people chuck away fridges (in Britain) and get a whole bunch of these things and blow them up," Colonel de Bretton-Gordon said.
There are tight controls in Iraq over the purchase of chlorine. In Britain, by contrast, anyone is allowed to buy 90 tonnes of the substance without a license.
It is understood that the authorities monitor the purchase of chlorine and other materials that could be used in bomb-making, to uncover any stockpiling.
However, as chlorine is freely available across the country, security sources conceded that it posed a risk.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
