Islamic State forces control large swathes of territory in Syria and Iraq
There
is a growing belief within the US government that the Islamic State
militant group is making and using crude chemical weapons in Iraq and
Syria, a US official has told the BBC.
The US has identified at
least four occasions on both sides of the Iraq-Syria border where IS has
used mustard agents, the official said.
The official said the chemical was being used in powder form.
A BBC team on the Turkey-Syria border has seen
evidence backing these claims.
The US believes the group has a cell dedicated to building these weapons.
"They're using mustard," the individual said of IS. "We know they are."
The
mustard agent was probably being used in powder form and packed into
traditional explosives like mortar rounds, the official said.
"We've seen them use it on at least four separate occasions on both sides of the border - both Iraq and Syria."
When these weapons explode the mustard-laced dust blisters those who are exposed to it.
What is mustard agent?
The term "mustard gas" is commonly used to describe the agent, but it is liquid at ambient temperature.
Sulphur
mustard sometimes smells - like garlic, onions, or mustard - and
sometimes has no odour. It can be clear to yellow or brown.
People
can be exposed through skin contact, eye contact or breathing if it is
released into the air as a vapour, or by consuming it or getting it on
their skin if it is in liquid or solid form. It causes blistering of the
skin and mucous membranes on contact.
Though exposure to sulphur
mustard usually is not fatal, there is no treatment or antidote to
mustard which means the agent must be removed entirely from the body.
How Syria's chemical weapons were destroyed
The official said the intelligence community believes the most plausible explanation is that they are manufacturing it.
"We
assess that they have an active chemical weapons little research cell
that they're working on to try and get better at it," the official said.
The official said knowledge to make the mustard agent is widely available, and it is not a complex chemical to produce.
The alternative theories are that IS militants found chemical weapons caches in Iraq or in Syria.
It
is unlikely that militants found the chemical agent in Iraq, the
official said, because the US military would have probably discovered it
during the military campaign it waged in the country for about a
decade.
The official said that militants were unlikely to have
seized the chemical agent from the Syrian regime before the regime was
forced to hand over its stockpile under the threat of US air strikes in
2013.
The US government's position continues to be that it is
investigating claims of chemical weapons use in Iraq and Syria, but the
official speaking to the BBC said that many intelligence agencies now
believe there is now enough evidence to back up these claims.
The official requested anonymity because that person was not authorised to speak about it publicly.
Special care must be taking when handling sulphur
mustard, because contact causes blistering of the skin, eyes and
respiratory tract
In recent days, the BBC's Ian Pannell, working from the Turkey-Syria border, has seen
new evidence of chemical attacks being carried out in Syria - potentially by the regime and rebels.
Syria
is supposed to be free of chemical weapons after a UN-backed deal that
saw the Syrian government hand over 1,180 tonnes of declared toxic
agents and precursor chemicals to the Organisation for the Prohibition
of Chemical Weapons (OPCW).
That process began in October 2013, and was completed by June of the following year.
More
than 200,000 people have died since the Syrian civil war began
following anti-government protests in early 2011, but only a tiny
percentage are believed to have died as a result of chemical weapons.
Last
month, the UN launched an investigation to determine which individuals,
groups or governments are involved in the use of chemicals as weapons
in Syria.
And that same month, the US military said tests on IS mortar fragments from fighting in Iraq showed traces of chemical arms.
US
Brig Gen Kevin Killea said in late August that the US had found traces
of the chemical agent sulphur mustard on mortars used by IS to attack
Kurdish forces in northern Iraq.
At the time, however, he also said that the tests were not conclusive and final testing was needed.
He described sulphur mustard as a Class 1 chemical agent, one that is rarely used outside of chemical warfare.
