# WTF, TSA? Is it 3 oz or 3.4? **URL:** \ **Category:** The BBQ Pit\ **Created:** [December 21, 2010, 9:37pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006 "2010-12-21T21:37:54Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Fell\_through\_the\_Ice](https://avatars.discourse-cdn.com/v4/letter/f/a9adbd/32.png) [@Fell\_through\_the\_Ice](https://boards.straightdope.com/u/Fell_through_the_Ice)\ **Post date:** [December 21, 2010, 9:37pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/1 "2010-12-21T21:37:54Z")
From your own website: [Liquids Rule | Transportation Security Administration](http://www.tsa.gov/311/index.shtm) Which is it? 3 ounces of liquids permitted in carry-on or 3.4. Your stupid website says both. I just bought bunch of 3.2-oz plastic bottles for our family’s upcoming trip. The package said “TSA approved size”. Idiots. :mad: ---
**Author:** ![stpauler](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@stpauler](https://boards.straightdope.com/u/stpauler)\ **Post date:** [December 21, 2010, 9:41pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/2 "2010-12-21T21:41:23Z")
I’m pretty sure it’s the 3.4 and that 3-1-1 is just trying to be cutesy. If it all fits in the ziploc, they’re not going to get picky. Personally, I just try and fly without liquids ([Lush’s bar shampoo with conditioner is actually really good](http://www.lushusa.com/shop/products/haircare/solid-shampoos/)). ---
**Author:** ![tumbleddown](https://avatars.discourse-cdn.com/v4/letter/t/e9bcb4/32.png) [@tumbleddown](https://boards.straightdope.com/u/tumbleddown)\ **Post date:** [December 21, 2010, 9:58pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/3 "2010-12-21T21:58:50Z")
It’s 3.4 ounces, which happens to be 100ml, which is nice and standard for the rest of the civilized world. This is another time when our insistence upon jettisoning the metric system is biting us in the behind. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [December 21, 2010, 11:28pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/4 "2010-12-21T23:28:58Z")
> [@tumbleddown](#): > > It’s 3.4 ounces, which happens to be 100ml, which is nice and standard for the rest of the civilized world. This is another time when our insistence upon jettisoning the metric system is biting us in the behind. You know what’s crazy? All American units are officially defined in terms of their metric conversion factors. WE WENT METRIC YEARS AGO AND NOBODY NOTICED! AAAAHHHHH!!! ---
**Author:** ![Arnold\_Winkelried](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@Arnold\_Winkelried](https://boards.straightdope.com/u/Arnold_Winkelried)\ **Post date:** [December 21, 2010, 11:48pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/5 "2010-12-21T23:48:45Z")
Hold on just one second there, pilgrim! When they say “1 quart-sized, clear, plastic, zip-top bag” do they mean a US liquid quart (0.946352946 litres) or a US dry quart (1.101220942715 litres) or an Imperial quart (1.1365225 litres)? I don’t want to hold up that line! ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [December 21, 2010, 11:52pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/6 "2010-12-21T23:52:36Z")
Quart bag is a defined size. 7 inches by 7 11/16 inches. Hmm, let’s see if it makes more sense in metric? 17.7 cm by 19.5 cm. Nope. > **[Amazon.com: Ziploc Double Zipper Quart Freezer Bags, 216 Count : Health &...](https://www.amazon.com/Ziploc-Double-Zipper-Quart-Freezer/dp/B002GJO6R6)** > > Double Zipper closure helps seal in freshness and lock out freezer burn with two zippers to close easily together for a secure seal. Extra thick plastic protects food in harsh freezer environment. What if you have gallon bags, but only fill a quart’s worth? Or cut it down to size? Will that get me a cavity search? ---
**Author:** ![Fell\_through\_the\_Ice](https://avatars.discourse-cdn.com/v4/letter/f/a9adbd/32.png) [@Fell\_through\_the\_Ice](https://boards.straightdope.com/u/Fell_through_the_Ice)\ **Post date:** [December 22, 2010, 12:37am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/7 "2010-12-22T00:37:02Z")
> [@stpauler](#): > > I’m pretty sure it’s the 3.4 and that 3-1-1 is just trying to be cutesy. If it all fits in the ziploc, they’re not going to get picky. Personally, I just try and fly without liquids ([Lush’s bar shampoo with conditioner is actually really good](http://www.lushusa.com/shop/products/haircare/solid-shampoos/)). Yeah I know, but you’d think with all the flack they’re getting right now these incompetent idiots would at least spend the 10 seconds to get it right _on their own fucking website_. “No more than three ounces” should mean exactly that if that is what they are declaring. 3.4 ounces is more than 3.0 ounces. So stupid in any case. Anyone could easily pack enough 3-ounce containers in a quart ziplock to equal 12 or 16 ounces. Get together with a few other terrorists who brought the same on board and they’ve got plenty of liquids to blow up a plane. It’s all just so fucking stupid. ---
**Author:** ![Isamu](https://avatars.discourse-cdn.com/v4/letter/i/7c8e57/32.png) [@Isamu](https://boards.straightdope.com/u/Isamu)\ **Post date:** [December 22, 2010, 2:14am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/8 "2010-12-22T02:14:01Z")
They also say “no liquids, aerosols or gels”. But in fact, “pastes” are also a no-no.\* \*They took my vegemite. ☹ ---
**Author:** ![Raygun99](https://avatars.discourse-cdn.com/v4/letter/r/6f9a4e/32.png) [@Raygun99](https://boards.straightdope.com/u/Raygun99)\ **Post date:** [December 22, 2010, 2:34am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/9 "2010-12-22T02:34:03Z")
Well if vegemite isn’t a controlled substance, it should be. ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [December 22, 2010, 2:55am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/10 "2010-12-22T02:55:57Z")
> [@Isamu](#): > > …They took my vegemite. ☹ I think vegemite looks more like an explosive than shampoo or body wash. But I’d be pissed. Mate. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [December 22, 2010, 3:01am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/11 "2010-12-22T03:01:05Z")
> [@Isamu](#): > > They also say “no liquids, aerosols or gels”. But in fact, “pastes” are also a no-no.\* > > \*They took my vegemite. ☹ There’s probably something in the regulations prohibiting dangerous and noxious substances. ---
**Author:** ![Darth\_Nader](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Darth\_Nader](https://boards.straightdope.com/u/Darth_Nader)\ **Post date:** [December 22, 2010, 4:33am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/12 "2010-12-22T04:33:22Z")
I would have just dug out big wads of vegemite with my finger and ate them 'til it was okay. Yum. Yes, I know that doesn’t work in the real world. I learned my lesson a decade ago when I had to dispose of excess vodka while re-entering the US. “But it’s the good stuff…” “Yeah, go ahead and lick it up.” ---
**Author:** ![Enderw24](https://avatars.discourse-cdn.com/v4/letter/e/ba9def/32.png) [@Enderw24](https://boards.straightdope.com/u/Enderw24)\ **Post date:** [December 22, 2010, 5:11am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/13 "2010-12-22T05:11:23Z")
Wait, according to the TSA, joking about terrorism while in line will lead to a metric ass ton of hurt. How much pain am I looking at? ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [December 22, 2010, 5:39am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/14 "2010-12-22T05:39:12Z")
> [@Darth\_Nader](#): > > Yes, I know that doesn’t work in the real world. I learned my lesson a decade ago when I had to dispose of excess vodka while re-entering the US. Really? They called you on it and dumped it? How much extra did you have? The few times I’ve been through customs with an excess haul of alcohol nobody seemed to care. ---
**Author:** ![digs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/digs/32/14889_2.png) [@digs](https://boards.straightdope.com/u/digs)\ **Post date:** [December 22, 2010, 6:03am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/15 "2010-12-22T06:03:06Z")
I have students that had no trouble buying large quantities of alcohol in… Mexico, I think it was, but had to give it up when they got to the USofA. Just because they forgot they were only 19… ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [December 22, 2010, 7:44am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/16 "2010-12-22T07:44:28Z")
> [@stpauler](#): > > I’m pretty sure it’s the 3.4 and that 3-1-1 is just trying to be cutesy. If it all fits in the ziploc, they’re not going to get picky. Except that they do. I once had a TSA agent insist on confiscating a 2.8 oz bottle because…well, because she wasn’t literate enough to fucking read the “2.8 OZ” that was molded into the bottle. > [@stpauler](#): > > Personally, I just try and fly without liquids ([Lush’s bar shampoo with conditioner is actually really good](http://www.lushusa.com/shop/products/haircare/solid-shampoos/)). Which is its own special form of insane, insofar as the preferred explosive formulations of truly professional terrorists, like Semtex, Composition C, and Torpex all all solid plastique-type explosives. I guess if you form it into a mold that imprints the word “LUSH” on it, it must be safe. > [@Isamu](#): > > They also say “no liquids, aerosols or gels”. But in fact, “pastes” are also a no-no.\* I’m increasingly tempted to bring a block of dry ice on board (in an FAA-approved vented container) and argue that because it sublimates it not a liquid or gel and therefore within their permitted regulations, despite the fact that it appears to be smoking like Humphrey Bogart. Stranger ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [December 22, 2010, 11:22am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/17 "2010-12-22T11:22:06Z")
Last I checked, the definition of “solid” didn’t include any information about its possible changes of physical state: dry ice is as solid as your clothes. The thing that gets me every time is that, since rechargeable lighters must now be in hand luggage (why? Too many complaints of “some asshole stole Grandad’s gold-plated lighter!”?), and given what you can buy in the duty-free, you’ve got the ingredients for a Very Traditional Incendiary Hand-Grenade right there. No need to bring them through customs, just buy them between security and boarding. ---
**Author:** ![dasmili](https://avatars.discourse-cdn.com/v4/letter/d/df788c/32.png) [@dasmili](https://boards.straightdope.com/u/dasmili)\ **Post date:** [December 22, 2010, 11:28am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/18 "2010-12-22T11:28:58Z")
When the the 3-1-1 rule first came out, it actually was 3 oz, not 3.4. They told us that it was equivalent to about 90 ml. We used to throw out a lot of 100 ml perfumes and things until they decided to get on the same page as the rest of the world. > [@Stranger\_On\_A\_Train](#): > > Which is its own special form of insane, insofar as the preferred explosive formulations of truly professional terrorists, like Semtex, Composition C, and Torpex all all solid plastique-type explosives. I guess if you form it into a mold that imprints the word “LUSH” on it, it must be safe. In my opinion, the extreme focus we have on liquids is counter-productive for this very reason. Our testers love putting a simulated IED in a test bag and watching the officers go right for the unrelated bottle of water. The rumor going around now is that the rules may be loosening up next year, and they are deploying a whole bunch of new bottle scanners. Fingers crossed. ---
**Author:** ![Muffin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muffin/32/4341_2.png) [@Muffin](https://boards.straightdope.com/u/Muffin)\ **Post date:** [December 22, 2010, 11:30am UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/19 "2010-12-22T11:30:46Z")
> [@tumbleddown](#): > > It’s 3.4 ounces, which happens to be 100ml, which is nice and standard for the rest of the civilized world. Which is communistic and therefore terroristic, thus 3 rather than 3.4 regardless of the regs. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [December 22, 2010, 5:06pm UTC](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006/20 "2010-12-22T17:06:48Z")
> [@Nava](#): > > The thing that gets me every time is that, since rechargeable lighters must now be in hand luggage (why? Too many complaints of “some asshole stole Grandad’s gold-plated lighter!”?), and given what you can buy in the duty-free, you’ve got the ingredients for a Very Traditional Incendiary Hand-Grenade right there. No need to bring them through customs, just buy them between security and boarding. Been hitting the _MacGyver_ box set pretty heavily, haven’t you? 😉 > [@dasmili](#): > > In my opinion, the extreme focus we have on liquids is counter-productive for this very reason. Our testers love putting a simulated IED in a test bag and watching the officers go right for the unrelated bottle of water. Indeed. Any security or analysis system that generates a large number of artificial false positives, e.g. searching grandma because her number came up in the lottery is going to dull the effectiveness of the actual system. I would be better to have testers going through security on a regular basis with simulated IEDs and/or displaying suspicious behavior than to impose blanket regulations of questionable effectiveness against any actual threats for the sake of “doing something”. Stranger [Next page](https://boards.straightdope.com/t/wtf-tsa-is-it-3-oz-or-3-4/565006.md?page=2)