On Saturday, March 9, FBI and Chicago police bomb techs located the secret underground hideout of would-be archvillain Joseph “Dr. Chaos” Konopka, who’d stashed more than a pound of sodium and potassium cyanide in a CTA passageway below Dearborn and Washington. Chemists warned that mixing readily available acids with such a poisonous payload would produce a cloud of hydrogen cyanide so toxic it could drop unsuspecting commuters in their tracks–in an enclosed space. Fortunately, in the well-ventilated Blue Line tunnels it couldn’t gas the rats. But Dr. Chaos wasn’t stocking just cyanide. After his 15-year-old minion squawked, the feds discovered a powered-up laptop–allegedly stolen from Ameritech–and a box of seven different compounds, all easily purchased from chemical-supply companies. Could those powders and crystals have been used to engineer a massacre? “I don’t see any interesting chemical pattern there,” says Wade Freeman, a chemistry professor at the University of Illinois at Chicago. “I see somebody roaming around a disused laboratory and taking things that look interesting.” Besides the cyanide, here are the chemicals Chaos was playing with:

Mercuric sulfate or HgSO4 A highly toxic, water-soluble white crystalline powder with numerous industrial applications, including removing mercury from gases and liquids. Can burn the skin but is most dangerous if mixed with an acid, because it gives off poisonous mercury gas.

Salicylic acid or C6H4(OH)CO2H A colorless, crystalline mild corrosive, extremely common in topical preparations used to treat acne, dandruff, cold sores, and warts. Also the analgesic from which aspirin is derived. Used in the production of a pleasant-smelling compound called methyl salicylate or “oil of wintergreen.” Could be mixed with sodium or potassium cyanide to produce hydrogen cyanide, but it’s so weak you’d need a lot of it. “You could probably pull that off with vinegar,” says Seth Darling of the University of Chicago’s Materials Research Science & Engineering Center. “There are much easier and more logical acids to use for that purpose.”

Phenolphthalein or C20H14O4 A white or yellowish white crystalline compound, found in any high school chemistry lab and used primarily to indicate whether a solution is an acid or a base. Laxative properties also make it an indispensable ingredient in a classic laboratory prank.

Potassium chlorate or KClO3 A colorless crystalline salt used as an oxidizing agent in the production of matches, fireworks, and explosives. Reacts violently with sugar or carbon. “One of the cool demonstrations that’s done in the chemistry classroom is to take potassium chlorate and melt it,” says UIC’s Freeman. “Then you drop a Gummi Bear in it and, man, do they react. The Gummi Bear burns to a little crispy critter in a big hurry with a lot of light and heat given off.”

Potassium ferricyanide or K3Fe(CN)6 Bright red crystals or powder, also known as “red prussiate of potash.” A common nonpoisonous laboratory reagent also used for tempering steel and electroplating and at one time for producing blueprints.

Art accompanying story in printed newspaper (not available in this archive): illustration/Carl Kock.