What It Means If A TSA Agent Swabs Your Hands

Going through security at an airport can be a little nerve-racking. Even if you do your best to follow the 3-1-1 liquids rule, take your shoes off, and pack nothing that isn't allowed, even normal behaviors at the TSA security checkpoints can get you flagged, like being overly chatty or keeping your eyes downcast. Sometimes you may be pulled aside for additional TSA screenings, which can include having your bags and hands swabbed to detect explosive material. If you've only had your bags swabbed, that usually feels like a routine procedure. However, when it's your hands, you may wonder why you were singled out and start to feel nervous. It can you feel like you did something wrong, even if you haven't. 

What the TSA is doing when it swabs your possessions, hands, or other items, is looking for trace amounts of materials that can be explosive, like glycerin, nitroglycerin, and nitrates. They swab the item or your hands, and then put the swab into an ion-mobility spectrometer, and if they detect anything, they may pull you aside for a secondary screening and ask you some questions. That can simply mean you've touched something that contains those materials, and there are quite a few non-nefarious reasons that they may be on your items and/or your person.

If you do test positive for trace amounts of materials that can be used in explosives, there could be a very normal reason for it. There is no need to worry. First, there can be false positives, and answering a few questions and a bag search may be all it takes to get you on your way. However, materials like glycerin and nitrates are both common in things like cosmetics, soaps, and shampoos. If you stopped in a restroom and didn't rinse your hands well enough, that may leave traces on your hands. They also may check your shoes and medical devices like wheelchairs or canes, as stepping or moving through things like fertilizer that stays on those items can set it off as well. They may find it on golf clubs or hiking poles for the same reason; you may use these materials for a hobby and retain trace amounts. 

Not rinsing your hands well enough, or bringing in shoes with fertilizer can be an airport mistake that can slow you down, but they're fairly easy to prevent. First, if you're washing your hands, it's a good idea to rinse thoroughly, and you can also use a hand sanitizer that doesn't have glycerin as an ingredient. If you're going through fields or places that use fertilizer, wash off your shoes. However, a secondary screening isn't something to worry about. It may add a bit of time to your travel, though, which is why it's a good idea to leave yourself plenty of time to get through security before your flight.