Originally Posted by average_passenger

I keep reading and hearing about false positives on explosives. How do you avoid them? I heard that even lotion and toothpaste can alarm the test. I guess you can ask them for new gloves from the box and a new swab but then you get branded as "difficult" for even thinking of asking.

Seriously, if the current testing method keeps giving false results, shouldn't they find a better method that is more accurate? Could the current methods be also giving false negatives?!

In the end, I guess it doesn't really matter, it's all security theatre. But what if I don't want to play along?