It's really not a big deal. On my shift at my checkpoint, we get an average of about 3 alarms a day total between our 3 ETD machines. Sometimes more, sometimes less. We average about 350-400 total samples in a normal 8 hour shift. Normal meaning average passenger load.

"Eventually"? Nice word. "Rationale" and "TSA" in the same thought? Oxymoron.

All metal and glass is a frozen liquid. Hard to believe, but true.

Eventually, either in five billion years when the sun expands, or next week if the global warming alarmists are correct, the earth's surface temperature will reach 1221 degrees F and the aluminum frame of my suitcase will melt into a forbidden liquid. For the sake of the children, TSA must ban all metal from aircraft immediately as potential eventual liquids.

right, to you its not a big deal. but imagine you don't work for the TSA--and youve just been told you tested positive for explosives...

i see where you're coming from. i used to work in an OR. we had routine, no big deal surgeries every day, unless you're the patient, then that routine appendectomy is scary as hell!

Hg?

The rationale that water ice in its various forms should be banned because it will eventually turn liquid presupposes that the liquid form is dangerous in some way. It is not. Water's supposed danger lies in the inability of TSA screeners to differentiate between water and dangerous liquids. The fact that a block of water is frozen at a non-extreme temperature demonstrates quite well that it is water and not something dangerous. Water melts at 0C (or a little colder), something easily checked by touching the container or using a thermometer.

It would therefore make a great deal of sense to allow solid, but not liquid, water.

Banning solid water because it can potentially turn to liquid water is like arguing that metal should be banned because it could be forged into a knife, except that knives are dangerous, while liquid water is not.

The technology exists; it's called a thermometer. Human hands will probably work just as well on non-insulated containers. Are there any practical "dangerous liquids" that have melting points near the melting point of water?

My point was that since frozen water will almost always be close to 0°C, it's trivial to identify it, much more so than as a liquid. Just touch the container (as long as it's not highly insulated) or use a thermometer.

Think of the children. Sand can be used in sandboxes, and children could possibly get hurt playing in sandboxes, so it makes perfect sense to ban sand.

(hey, that logic is just as good as any other TSA logic)

Child terrorists use sand to hide their toxic liquids.

Risk Management vs. 100% Risk Avoidance.

Since 2001 how many tons of unscreened cargo has been flown with no contraband taking down a plane? Did TSA just get lucky?

There was the one 1996 incident with nitroglycerine. The one incident with a shoe. (both outside the US and both pre TSA) Now the whole TSA is Obsessive Compulsive for shoes and liquids and now you feel the Biggest Threat to Aviation is FROZEN NITROGLYCERINE.

When every pound of cargo is screened as good as a passenger, then worry about FROZEN NITROGLYCERINE.

If future terrorists as dedicated as the 9/11 crew then the easiest way to evade current security is to surgically implant 10 pounds of C4 inside the body. NONE of the current measures will find it. Only a full body X ray will find it. If your Goal is 100% Risk Avoidance of ALL POSSIBLE threats then ALL passengers and ALL cargo is X-rayed starting Tomorrow. Period.

Then worry about Hollywood plots involving FROZEN NITROGLYCERINE.

PS: Don't eat or pound the yellow sand.

PPS: Actually sand should be banned. Sand can carry microbes and spores and invasive weed seeds. People should not bring home sand samples especially from overseas as it is a real threat to domestic agriculture.

Awesome advice! ^

Keeping solids solid is not sufficient to prove they are harmless. So what?

Frozen water will be in the process of melting, so it will be at 0°C. Nitroglycerin melts at 13°C. That being said, nitroglycerin mixed with other compounds can have a lower melting point. However, do you guys have ETD machines? Don't they detect nitroglycerin?

I still fail to understand the logic here. Dynamite, TNT, and many other explosives that are far more dangerous to aircraft (by merit being safe to transport) are solid, yet the TSA allows solids. Why? There is no way to differentiate between many solid explosives and [insert benign material here]. Of course this ignores ETD, which the TSA seems to ignore for liquids.

But isn't swabbing the container the liquid is in sufficient to take care of this issue?

Really?

So leaving your bags out during a rainstorm (i.e. dunking them in a bathtub) and arriving at the checkpoint after a shower or while covered in sweat are the tricks to getting explosives past the ETD?

My point was serious. The inability of ETD machines to work with wet swabs seems like both a vulnerability and a potential problem for innocent passengers.

For example, I would like to know if I might be stopped from bringing a soaked bag past security.

Just remember fellow FTers, request a private screening for all secondaries.

Thanks, that's very interesting (well, maybe only to science geeks). What I had in mind was more like a dispersion problem, where a small amount of it piles up someplace and affects a pet or baby on the floor, machinery, etc.

Seems to me the newer widebodies, which have no pax-adjustable airflow, already contribute to discomfort/illness in sensitive pax. Several times in the past couple years I've seen pax given O2 on long (>10-hour) flights, once on waking suddenly with a raging headache and nausea myself. The cabin temp was oddly high also, in that case.