The Transportation Security Administration (TSA) recently issued a bulletin warning its agents of the danger of thermite-based incendiary devices.

Thermite is a mixture of rust and aluminum that can elude bomb detectors. When ignited, it produces a toxic gas that can act as a nerve poison, in addition to creating thick black smoke.

The warning stated that thermite "could result in catastrophic damage and the death of every person onboard."

Commercial pilot and publisher of JetWhine.com, Robert Mark, appeared on "Fox and Friends Weekend" to share insight on thermite and other threats to air travel.

"If one were able to be smuggled onto an airplane, it would be pretty disastrous," Mark said. "Because the heat that is produced by one of these things is so intense it would probably melt right through the airplane alone."

Mark said that when he tried to talk to some of his contacts at the Department of Homeland Security about the threat posed by thermite, they told him the issue was classified.

Mark also weighed in on the troubling report that 1,400 TSA security badges have gone missing at some of America's biggest airports.

He revealed this isn't as big a threat as some might fear, because the badges can be deactivated, much like a stolen ATM card. Plus, he said, another layer of security is a PIN ID that an employee must punch in as they swipe their card.

FoxNews.com reported:

Neither the FBI nor TSA said there was a specific threat by terrorists involving thermite, and a source “with knowledge of current threats” overseas told The Intercept that extremists are currently interested in other incendiary devices that do not involve the deadly chemical combo.

In addition, while it would be difficult to spot in metal detectors, experts it would be an unwieldy weapon: a terrorist would have to bring a lot of it on board to do any real damage – which would raise suspicion -- and they would have to find a way to both place it and ignite it.

Still, TSA officials who spoke with The Intercept expressed frustration that while they were provided the intelligence, they weren’t given much guidance on what to do with it. For example, they were told they had to use a non-water or non-halon extinguisher against a thermite reaction, but offered no instructions onhow, or what to use otherwise.

Aviation officials concurred. “They say to identify something we don’t know how to identify and say there is nothing we can do,” one federal air marshal said. “So basically, we hope it’s placed somewhere it does minimal damage, but basically we’re [screwed].”

Watch more above.