Detecting Explosives and Drugs

Ever wonder what government agents are checking for with their swabs at airports? We are told that it is a check for explosives, but, since there is no single chemical that defines “explosive,” they are necessarily checking for certain chemicals that are found in some explosives but may also be found in other benign materials. Among the common items that might set off an alarm at an airport when they swab for explosives are heart medicine (those containing nitroglycerin) and fertilizer. This latter one may explain why that poor baby’s stroller set off an alarm a few weeks ago, leading unthinking and uneducated TSA goons to search the baby’s diaper.

(Of course, all of this ignores that (1) there are legitimate reasons that one may actually be handling explosives and have the residue on there person or belongings and (2) not all explosives will be detected this way.)

This reminds me of a story I heard about automatic drug sniffers that US Customs used (I don’t know if they still do). The sniffers can’t detect drugs directly, so instead they are programmed to detect the chemicals that are used to process drugs. But, the “smell” of lighter fluid overlaps with some of these chemicals, so when a person is carrying a Zippo in their pocket, the alarm would go off. The story I heard was that a man was detained and searched when the alarm went off, but Customs couldn’t find anything. So they called the company manufacturing them (guess which tax-feeding company was manufacturing the sniffers!), who sent an expert who quickly realized the source of the error. The mundane was presumably free to go afterwards.


8:22 am on June 6, 2011