The treaty lists the agents and precursor chemicals that will be subject to control.

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Last week, troops from the 101st Airborne found a stash of chemicals, which was investigated as possible nerve agents, but the material turned out to be pesticides, Freakly said.

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The solution (pun intended) involved tacking sodium dithionite and hydro-chloride onto the antibiotic, making it into a water-soluble salt. (Drugs prepared as hydrochlorides are commonplace.) To keep the chemicals from oxidizing, Adams tested 50 different agents, such as citric acid and ascorbic acid, and played with various ratios until he got the right pH balance.

FORBES: Magazine Article

In 2011, the US director of national intelligence concluded that Syria remained "dependent on foreign sources for key elements" of its chemical weapons programme, including precursor chemicals, which are generally dual-use chemicals that can be combined to produce blister or nerve agents.

BBC: Syria's chemical weapons stockpile

In 2003, federal agents discovered "nearly two pounds of a cyanide compound and other chemicals that could create enough poisonous gas to kill everyone inside a space as large as a big-chain bookstore or a small-town civic center" at the home of Judith Bruey and her husband, William Krar, according to an Associated Press report.

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The problem is that anyone who can produce modern drugs, vaccines and chemicals for agricultural and industrial use also can produce deadly viruses, toxins and nerve agents.

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But many are anxious about chemicals--acids to dissolve minerals and create cracks, surfactants to make fluids more slippery, agents to prevent bacteria that corrode pipes.

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This, he believes, will make it possible to work out which country, even which factory, supplied the original chemicals for the mustard gas - it will not be possible to trace the source of the nerve agents.

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