Editore"s Note
Tilting at Windmills

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April 30, 2007
By: Kevin Drum

PROBLEMS WITH THE METRIC SYSTEM....Megan complains today about the rigidity of TSA regulations for carrying small bottles of liquid onto airplanes. That's nothing. A reader who works as a TSA screener emailed me a couple of weeks ago to say that he has had "easily dozens of run-ins with passengers (and other screeners)" about whether it's legal to carry on a 100 gram bottle. You see, 100 grams is 3.52 ounces by weight (just over the limit!). But, by volume, 100 grams of water = 100 milliliters, and 100 ml is 3.38 fluid ounces (just under the limit!). So that 100 gram bottle probably contains 3.38 fluid ounces of stuff, but 3.52 avoirdupois ounces. What to do?

Just thought you'd all like to know.

Kevin Drum 12:58 PM Permalink | Trackbacks | Comments (36)

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...so are "barrels" metric, English ...or uniquely "USA"?

World wide oil production has already peaked. It's pretty convincing to me," says T Boone Pickens.

Posted by: Darryl Pearce on April 30, 2007 at 1:15 PM | PERMALINK

That's funny considering the EU and all other countries to adopt similar regulations as us use 100 mL (not mg) as the standard measure. How the hell does 3.5 ounces by weight even come into it? Doesn't that depend on the dnesity of the material? I'm sure toothpaste weighs more than lotion. So how can you have a 3.5 ounce container BY WEIGHT?

Posted by: Armen on April 30, 2007 at 1:18 PM | PERMALINK

What to do?

Write laws using metric measurements so we don't have these problems. The law should have said nothing over 100 ml, if that was the intent. Writing laws based on ounces, which can represent weight or volume, is just stupid.

Posted by: Wapiti on April 30, 2007 at 1:22 PM | PERMALINK

What to do?

What to do? Get rid of the ridiculous regulation that was based on a pie-in-the-sky fantasy plot that would have never worked in the first place.

Posted by: trex on April 30, 2007 at 1:22 PM | PERMALINK

Where are the Christian fundamentalists who believe that we should be using cubits as a standard unit of measure? I predict that they must exist, somewhere.

Posted by: lampwick on April 30, 2007 at 1:23 PM | PERMALINK

Ah hell - do it all by moles. That'll make heads explode at the very least (now off to chem lab...)

Everyone has Avogadro's number, after all.

Posted by: Blue Girl, Red State (aka G.C.) on April 30, 2007 at 1:25 PM | PERMALINK

I'm as confused as Armen. I've never seen a fluid container measured by weight. It's always volume. Loose solid product are measured by wieght, because of settling issues but not liquds. I also wonder: is this net weight or gross weight? That would make a big difference if it's a glass bottle.

Posted by: fostert on April 30, 2007 at 1:25 PM | PERMALINK

This isn't a problem with the metric system, it's a problem with the English system.

Posted by: GSmith on April 30, 2007 at 1:29 PM | PERMALINK

Get rid of the TSA & all the rest of this stupid fascist police state stuff. Oh and show all the junior high school bureaucrats the door.

Idiots to the left of me, idiots to the right of me.

"...The American fascist would prefer not to use violence. His method is to poison the channels of public information..." - Henry Wallace

Posted by: daCascadian on April 30, 2007 at 1:32 PM | PERMALINK

We can muck about with Social Security, continue to throw money at SDI, even privatize the post office at some point.

Why. The. HELL. Do we still use the godddamn English system that even the English themselves no longer use?

Just do this one thing, Dub. Executive Order. All measurements in the country to be in metric only by 1 May 2008. You want a legacy, there ya go.

Posted by: Matt on April 30, 2007 at 1:34 PM | PERMALINK

Is this regulation still in effect? I thought it was cancelled once the "binary bomb" intelligence was revealed to be politicized crap and impossible to carry out anyway. Besides, if you really need a 1 liter bomb, you just have a team of 10 people.
Uh, excuse me, there are some men in black suits knocking on my door...

Posted by: SP on April 30, 2007 at 1:43 PM | PERMALINK

Time to go metric: Oct 10, 2010

10 by 10 by 10-10-10!!

Posted by: Laura on April 30, 2007 at 1:45 PM | PERMALINK

zimple rule change:
Scary Brown People: no liquids
Others: anything they want

Posted by: thersites on April 30, 2007 at 1:48 PM | PERMALINK

The metric system is the tool of the devil! My car gets 40 rods to the hogshead, and thats the way I likes it!

Posted by: Brian on April 30, 2007 at 1:58 PM | PERMALINK

I recently had to explain to my 3 year old daughter why I was borrowing her toothpaste - someone at the airport took mine, and they were wearing a jacket marked TSA.

Does anyone in their right mind think that these idiotic show policies do any good? They confiscate tooth paste, but leaving chemical plants and cargo containers wide open. Maybe their hope is that would-be-terrorists will find the security holes so blatant, that they'll figure that there has to be a catch.

Posted by: alex on April 30, 2007 at 2:02 PM | PERMALINK


Those little rodents are good for nothing.

Avogadro? Is that you lawn doctor?

Posted by: Yancey Ward on April 30, 2007 at 2:02 PM | PERMALINK

Ounces are not a metric unit of measurement.

Posted by: neil on April 30, 2007 at 2:08 PM | PERMALINK

This is a little too complicated for faith based thinking.

Posted by: Brojo on April 30, 2007 at 2:09 PM | PERMALINK

simpler rule change:

metric = foreign = bad

Posted by: thersites on April 30, 2007 at 2:15 PM | PERMALINK

what if it's 3.38 fluid ounces of mercury (or nitroglycerine for that matter)? isn't security theater fun?

Posted by: supersaurus on April 30, 2007 at 2:16 PM | PERMALINK

> 100 grams is 3.52 ounces by weight

For water maybe. Milk, hand lotion, cough syrup, barium-based medication: all have different densities.


Posted by: Cranky Observer on April 30, 2007 at 3:06 PM | PERMALINK

Cranky got there before I got back. The AMUs of the constituent elements determine weight. This reg is just...ignorant.

Posted by: Blue Girl, Red State (aka G.C.) on April 30, 2007 at 3:21 PM | PERMALINK

Somebody is actually calling people on .02 of an ounce?

Heck, just remove the cap and take a good whiff. You could probably inhale .02 of an ounce.

Posted by: Quaker in a Basement on April 30, 2007 at 3:37 PM | PERMALINK

Shouldn't a post entitled "Problems with the metric system" be about, you know, a problem with the metric system.

Posted by: Ben V-L on April 30, 2007 at 3:37 PM | PERMALINK

What to do? When you're at the airport look very earnest and pretend very hard that you care about this minute difference. Then do whatever the TSA person tells you to do, because being right isn't satisfying enough to put up with full body cavity searches and missing your flight.

Posted by: cowalker on April 30, 2007 at 3:51 PM | PERMALINK

Brian (like Grampa Simpson) needs a new car - I think even the new Army tanks get at least 40 rods to the hogshead! Why, that's a mere 6 furlongs per firkin!

I've never understood the combination of the small bottle rule with the ziploc bag rule. If you needed more than 3.5 oz of magic exploding fluid to be dangerous, just put two small bottle in your ziploc. If it takes more than will fit in a ziploc, why bother with the 3.5 oz rule? I'm sure Top Minds familiar with the chemistry of magic exploding fluids know the answer, but it is of course classified, and just for asking the question I'd be put on the no-fly list, but like the thousands of other Americans with my perfectly normal Anglo-Saxon name, I'm already there.

Posted by: biggerbox on April 30, 2007 at 3:53 PM | PERMALINK

It isn't about security, though, is it ? It's about the role of state being taken to ridiculous extremes by those with diametrically opposite simultaneous prejudice : the state has too much power, I want more power than I've been given.

Posted by: opit on April 30, 2007 at 4:16 PM | PERMALINK

Where are the Christian fundamentalists who believe that we should be using cubits as a standard unit of measure?

They can't even agree how long a day was.

Posted by: Nemo on April 30, 2007 at 4:48 PM | PERMALINK

Jesus fuck. Just imagine that whining Ayn Rand wannabe bitching to security personnel because she's too fucking cheap to toss a shampoo that she never used anyway.

Time to issue billy clubs and tasers to airport screeners.

Posted by: Howard Doark on April 30, 2007 at 5:07 PM | PERMALINK

The English measurement system is good for something though, namely building.

A base twelve system leaves you with the smallest unit the most divisors. I.E., 1, 2, 3, 4, 6, and 12.

Even countries like Canada and England, both metric countries, continue to mark their building supplies with English measurement because of this.

Posted by: Dr. Morpheus on April 30, 2007 at 5:11 PM | PERMALINK

The regs are about fluids. Therefore, the reg isn't ambiguous; ounces should be construed to mean fluid ounces to internally make sense.

Therefore, a 100g bottle of any liquid as dense as water or more dense (lotion, etc.) should come in at 100ml or less, and therefore be permissible.

Posted by: asdf on April 30, 2007 at 5:53 PM | PERMALINK

TSA is so useless. I travel about once a week on business and the invasion one suffers entering the airport is always the worst part of the trip. It makes me sad to see the TSA thugs patting down old women in wheel chairs and elderly gents with canes.

There are lots of ways to get what you want past these guys. You just have to know a little physics. The purpose of the TSA is not to protect our safety. Their purpose is to educate the citizenry to be comfortable with giving up their rights and complying with government "authority figures."

The simplest way to get past them would be to put your own labels on the bottles and tubes. Unless you are off by a factor of five or ten I doubt they would tell whether your container was really 3 ounces or 5 ounces, especially if it was an odd shaped container. They don't care how much material is in the container. If it is half full and the label says 4 ounces they take it away. They only know what the label says.

Posted by: JohnK on April 30, 2007 at 7:13 PM | PERMALINK

I had a screener in at a CA airport gleefully remove and discard a toothpaste tube in my luggage. The tube was one I regularly took with me for travel and had been rolled down until all that was left in it was a dab of paste about sufficient to make a mound about the size of a quarter if fully discharged.

It was confiscated because the tube, when full, contains 14 oz. of toothpaste. Same thing happened with a small 4 oz bottle of hair creme containing enough of the product to coat the outside lower edge of the jar bottom. Jar was too large.

They asked if I wanted to take my carry on back out to the check in counter and check it through and then return.

After asking if I had STUPID printed on my forehead, I told them, "Please take these items and send them to the TSA Hall of Fame to demonstrate that the world is now a safer place." I had steam coming out my ears. Probably lucky I didn't get arrested for being impolite or sent to Syria for a few months of isolation and "we do not torture."

Posted by: dweb on April 30, 2007 at 7:46 PM | PERMALINK

Isn't the federal government supposed to use the metric system as a matter of law ?

Posted by: Fifi on May 1, 2007 at 1:42 AM | PERMALINK

Kevin and many of the commenters are confusing volume with mass with weight.

The volume of a bottle is given in volumetric ounces. If you put a denser liquid in it, it will weigh more (in weight ounces), and if you put a less dense liquid in it, it will weigh less (in weight ounces).

It's confusing that both weight and volume use the same term. One virtue of the metric system is that it clearly distinguishes between mass and volume. And no, I'm not going into the difference between mass and weight here.

But, figuring back from the TSA regs, it's volume they seem to be concerned about, not weight or mass, so most of Kevin's post is irrelevant.

Let's not add this confusion to that which already reigns at airport screening.

Posted by: CKR on May 1, 2007 at 10:19 AM | PERMALINK

The TSA limits containers to 3 ounces, not 3.5 ounces. 100ml is .38oz over the limit. Also, it's pretty clear from the TSA website that they're referring to volume - the amount the container can hold - and not weight of the item it contains.

Posted by: fl on May 1, 2007 at 11:47 AM | PERMALINK



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