Sunday, August 16, 2009

Speed Smells: CSI Molecular Edition

From a late February edition of the Evansville Courier & Press:

Chemical smell leads deputies to meth lab.

Two Mount Vernon, Ind. residents are facing numerous charges after police traced a chemical smell to a meth lab in their yard barn . . .
Last week the action moved to Mississippi:
Authorities say a foul smell on Lovers Lane in Vicksburg led police to a methamphetamine lab.
As we’ve pointed out more than once, no matter how well-disguised the lab it’s always the smell that gives away the location.

But what exactly does a meth lab smell like? Local press accounts are maddeningly vague when it comes to describing the telltale aroma. It’s clearly unpleasant, but in what sort of way: Skunky? Barfy? Smoky?

Driven by a intellectual need to pin culturally important odors to specific molecules—plus an annoying bloated feeling from watching too many CSI reruns recently—First Nerve did a little googelizing and discovered “The Meth Lab Menace: What responders should know about these dangerous environments.” Written by Doug Hanson, PhD, this harrowing account originally appeared in EMS Magazine and is more compelling than any TV cop show.

Among other things, Hanson lays out the classes of chemicals likely to be found in a makeshift meth lab—the ingredients vary by recipe and by whether the final product is powder, rock or crystal. Common to all variations of the procedure, however, are powerful solvents and acids, gases, metallic salts, and a handful of other inorganic compounds.

From an olfactory POV the solvents are major contributors. According to Hanson these might include:
acetone, methanol, isopropanol, benzene, toluene, Freon and ether. These can come from common sources like nail polish remover (acetone), fuel additives like HEET (methanol), rubbing alcohol (isopropanol), scientific supply houses (benzene, toluene, diethyl ether) and old air conditioners (Freon). Other solvents that might be present include kerosene, petroleum ether and chloroform.
This covers a fat slice of the olfactory spectrum: from the sweetness of ether and benzene, to the harsher impact of isopropanol and methanol, to the engine room ambience of kerosene.

Add to these the gases such anhydrous ammonia and methylamine, and acids such as sulfuric acid and hydrochloric acid, and you have an olfactory hammer waiting to drop on the unwary intruder. No wonder the neighbors notice. And no wonder local reporters have a hard time describing it.

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