saizai

Going through 800+ pages of FOIA/PA docs looking for interesting bits etc, I came across two interesting quotes responding to two different complaints:

"… the contact lens referred to is a product called "ClearCare" which contains hydrogen peroxide. This can be used together with other ingredients as an explosive material."

"However there has been an ongoing debate about this particular type of contact lens solution. Some airports allow and some don't."

Evidently they think someone's going to manufacture acetone peroxide on a plane. Or maybe not. Evidently they don't even have an agency-wide decision about whether hydrogen peroxide is or isn't an "explosive material".

ETA, yet another complaint: "Contact lens solutions are considered over-the-counter medications and are allowed in carry-on bags."

… in other words, they have a deliberate and inconsistent policy of violating their own medical liquids policy. How. Interesting.

shenxing

So are you going to post the docs for us to see or not?

catandmouse

Hydrogen peroxide has two types of use.

• Rocket fuel
• Cleaner or bleach

As rocket fuel, the hydrogen peroxide is at a high concentration, is highly explosive and needs a large, complicated chemical plant to manage it. It is highly unstable.
As a cleaner, bleach, it is highly diluted. It is mildly corrosive, so if you do end up being in contact with it, you need to wash it off with water. It is non-explosive, stable and can be stored in pretty much anything (plastic bottles for example). It isn't dangerous.
Unfortunately some people mix the two uses up and think that contact lens solution made up of hydrogen peroxide can be used as rocket fuel.

Dovster

Hydrogen peroxide in contact lens solution is prohibited out of an abundance of caution.

There have been reports that terrorists are planning to hijack a plane, turn it into a rocket, and take all the passengers to Mars.

saizai

Yes, once I've finished redacting them for my own privacy (various private contact info etc is scattered throughout).

FliesWay2Much

H2O2 was used as a "monoprop" aircraft (X-15) and satellite thruster up until the early 1970s. The Germans invented this type of attitude control thruster back in the 1930s. The peroxide had to be 90% pure and relied on a catalyst bed to break it down into its components. The chemical reaction produced a gas (ordinary steam) that was compressed through a nozzle. To demonstrate how toxic 90% pure H2O2 is, the space industry replaced these thrusters with hydrazine (one whiff and you're dead before your brain comprehends you sniffed it). I suppose you could use the steam from your carry-on H2O2 thruster to scald the crew, take over the airplane, and steam-iron everyone's clothes while you were at it.

During most waking hours, the TSA is just plain stupid.

saizai

OP ETA, yet another complaint: "Contact lens solutions are considered over-the-counter medications and are allowed in carry-on bags."

eastport

Hydrogen peroxide is also used in the "jet pack" device.

It's major advantage is that it's a very reliable propellant. Just put it in contact with a catalyst and it degrades into steam. It's major disadvantage is that there are many catalysts, and your container full might just spontaneously degrade into steam.

The way to avoid this is to dilute the hydrogen peroxide with water. But a safe-to-handle-unsealed concentration is pretty much useless as a precursor for making (more) dangerous compounds.

Oh, and the energy density isn't great. The "jet pack" only has fuel for 30 seconds to 4 minutes of flight -- barely enough for a carefully planned stunt.

FliesWay2Much

Yep -- that's why the space-faring nations stopped using peroxide thrusters in about 1970. But, alas, the TSA never met a threat it didn't like.

Loren Pechtel

I[sub]SP[/sub] of hydrogen peroxide is 161 seconds.
I[sub]SP[/sub] of hydrazine is 220 seconds.

That's a very big reason to use hydrazine.

MSDS:
Hydrogen peroxide, 60%: http://msdsviewer.fmc.com/private/do...YPURE%20BULK~~
Hydrazine: http://www.sciencelab.com/msds.php?msdsId=9924279

I'm having a hard time comparing them (and I can't find a MSDS for the 90% stuff) but the hydrazine looks a lot nastier.

84fiero

The ClearCare solution contains only 3% hydrogen peroxide, similar to the bottles sold in the drug store for other health and beauty uses. The most dangerous thing about the solution is, if one is still half asleep and accidentally uses liquid directly from the ClearCare bottle thinking it's regular saline.

Not that I would know from experience.

FliesWay2Much

You have to handle hydrazine in full SCAPE suits. They told us in the launch complex safety training that it smells like decaying fish. They also told us that this would be the last thing we would smell.

shenxing

The government, from their completely implausible, manufactured liquid bombing plot from 2006, claim that hydrogen peroxide is of importance in bombing planes. Their chemical detectors necessarily measure traces of substances, meaning that the detection threshold is very low. They cannot tell a trace originating from a benign 3% solution from a trace from a 90% solution.

RadioGirl

That "%" symbol mean "percent", don't it? Isn't that, like, you know, math? TSA don't do math. People that are good at math are definitely spicious.

Y'all use a lot of big words in this thread too. That's spicious too.

saizai

That itself seems like a serious security problem worth Congressional investigation.