Something as simple as glycerine in your lotion could trigger a false positive when it's swabbed and put through trace detectors at airports. Photo / iStock
Something as simple as glycerine in your lotion could trigger a false positive when it's swabbed and put through trace detectors at airports. Photo / iStock
Going through airport security can be stressful enough, just separating your liquids and creams and removing your laptops and tablets at speed.
But did you know you could be pulled aside for something as harmless as having recently applied hand cream?
A common ingredient in lotion - glycerine- could trigger a false positive when it's swabbed and put through trace detectors at airports around the world. And in fact, several instances have been reported in the USA in the past.
The explosive trace detectors (ETD) at airports are designed to screen for all sorts of trace materials, including chemicals used to create explosives.
However, the list of substances that the ETDs are screening for is not public information according to Nik Karnik, senior director of product management and strategy at Morpho Detection.
Morpho Detection is one of several companies that manufacture ETDs used in the UK and elsewhere.
Karnik told MailOnline Travel: "As opposed to explosive devices of decades past, today those seeking to do harm are often turning to homemade explosives (HME) - that can often be created with items purchased at Tesco or Wal-Mart.
"These devices, and their precursors, contain chemicals and substances that can create an explosion."
He added: "Explosive trace detectors (ETD) by definition are looking for microscopic traces of explosives, too small for the human eye, and is based on contamination.
"Contamination means that if you handle or are in close proximity to suspect chemicals or substances, tiny particles can live on your hands, clothes and baggage for days."
For instance, ingredients such as glycerine are occasionally found in beauty products and household items like soap, can both be used for making bombs.
And in turn, they could cause the explosives detector to read a false positive.
But it's not just beauty products that can set the alarm bells ringing - even heart medication can trigger a false positive.
Some heart medication contains nitroglycerine, which is another chemical found in some explosives.
This means that those who take the medication and those who might regularly use it, like paramedics, could also inadvertently set off the sensors.
The same chemical can also be found on fertilisers, which makes items such as golf clubs and shoes another place where explosive material can be detected - especially since the particles can stick around for days.
For security, the regulated acceptable false alarm rates are not available to the public but the guidelines are constantly updated and varies from region to region. Photo / 123RF
For security, the regulated acceptable false alarm rates are not available to the public but the guidelines are constantly updated and varies from region to region.
Instances of false triggers are rare but they have been reported at larger airports in the US, including Dallas-Fort Worth International Airport where an NBC 5 employee was stopped in 2013 after glycerine was detected during a screening.
US Transportation Security Administration (TSA) spokesman Ross Feinstein told NBC 5 that the problem with false positives is "not uncommon".
He said: '(The technology) must be sensitive enough to detect even the slightest presence of explosives on a passenger or a piece of luggage.
"Due to this sensitivity, on occasion, commonly used items can render a false positive alarm during screening."
Another passenger was travelling through Columbus in Ohio when she tested positive for nitrates after slathering on hand cream according to news9.
She was pulled aside into a private room for additional checks but was eventually allowed to leave 15 minutes later.
A UK Department of Transport spokesperson said: "The safety of passengers is of paramount importance and it is right that strict security procedures are in place for the protection of air travellers.
