You can't bring knitting needles on board an aircraft either, 'cause you might knit an Afghan.

Seriously though, you can be searched if any nitrates are detected on you or your baggage. Which means that if you've visited a farm (including "organic" ones), handled any fireworks, fired a rifle as a hunter or as a member of an Olympic shooting team, use nitroglycerin for angina, or, I suppose, squash a hot dog on yourself, you'll set off the detectors.

There's a difference between "reasonable precautions" and "official paranoia."