Wednesday, February 25, 2009

3 oz or 3.4 oz? What gives???

Short answer: 3.4 oz. For more details, read on…

OK, here’s the scoop. If the U.S. would have switched to the metrics system in the 70s, this wouldn’t be an issue. How many of you out there had to learn the metric system in school only to never use it…

When TSA lifted the total liquid ban and implemented the 3-1-1 program, the permissible amount of liquids, aerosols and gels was 3oz. Press releases went out, WebPages were updated, and signs were printed and shipped out nationwide to 457 airports.

When TSA rolled out 3-1-1, the European Union was not on board yet. When the EU decided to lift the ban and allow liquids to travel, the amount permitted was 100ml. Well, as those of you who like me had to learn metric conversion in grade school, youmight remember that 100ml = 3.4oz. not 3 oz. In order to align with the EU, we decided to allow liquids in containers up to 3.4oz. We also decided to keep our signage the same to maintain consistency. (Besides, 3.4-1-1 just doesn’t have the same ring to it.)

From a marketing perspective, 3 ounces was easier to remember than 3.4. For the European Union, 100 milliliters was easier to remember than 89. So, behind the scenes, we’ve been allowing up to 3.4 ounces, but it hasn’t been reflected on the web or in signage.

We’ve read your concerns here on the blog, so from now on, we’ll use 3.4 on the blog when talking about liquid limits, and also make changes (as soon as possible) to the TSA web site. I worked with Lynn on this and she has crafted a new response for the contact center to use when communicating with the public. We are also going to send a message to the workforce as a reminder.

Some people have asked why we don’t convert the net weight of the toothpaste to volume since they are different. Good question. The 3.4 container/volume rule was created to make it simple and streamlined for both passengers and our officers. As you could imagine, taking weight into consideration would be a wrench in the spokes. I’m sure the public doesn’t want our officers using scales or conversion charts, etc.

I hope this has helped you better understand the 3.0/3.4 oz. conundrum.



EoS Blog Team


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BWL Studenten said...

Wow, between this and the fact that some TSA guys call Saline medicine and some don't, the liquids rule just gets more and more confusing. Thanks for making it all clear as mud!

Michael said...

Why is TSA still using signs that say the limit is 3 ounces.
If you go to, you see the limit is 3.4 oz, but if you look at the files in the .pdf links on that page, they point to 3 ounce signage.

Keep the 3-1-1 slogan if you must, but put "3.4" on the sign. I was forced to throw away a 95ml bottle of Listerine at LAX a few weeks ago because it was also labeled as 3.2 ounces.

Anonymous said...

I wish they could raise it to 4 oz. which is the size of mini-yogurts and a few other food items.

Come on. How is that extra 0.6 ounce dangerous?

No one sells yogurts in 3.4 ounce containers. I suppose one could find little plastic containers that are less than 3.4 oz. and fill them from a larger yogurt container but you know, air travelers are usually in a hurry to catch their plane and don't always have the time for such things.

Thanks for considering my suggestion!

Anonymous said...

Wow so the TSA changed policy and didn't tell the public? Why am I not surprised by this. Security Theater nonsense.

Graham Gallagher said...

Why are people concerned about the difference between US measurements and the rest of the world?

I just know when I visit the USA and fill my car up it costs less than any where else - now why is that?

Cody Taylor said...

Conversion charts would be an easy solution. Weight Down
When it doubt just look.

After a while the most common sizes and weights would become second nature to the TSOs.

Anonymous said...

I love how this was posted in 2009, it is now 6 years later, and from someone who travels 4-6 flights per week, it seems like TSA EMPLOYEES STILL DON'T KNOW THE RULES.

A few experiences...
1- Confiscated my plastic butter knife, yes the same kind you get at McDonalds that couldn't cut through actual butter (maybe margarine but that's about it). I later saw one on the floor inside security and thought about shouting "Ahh! A knife!" but then thought better of it...
2- Found someone else's jewelry in my checked bag... didn't know they like to play musical bags with other people's stuff
3- Had a locked gun case stolen by a TSA agent who obviously handled all of the firearms before putting them back in the case... (they put them back wrong and had their fingerprints over all of them). Btw, the guns were missing for 2 days and then they arrived UNLOCKED where anyone could access them.
4- Witnessed someone take pepper spray through security
5- Witnessed someone take out large quilting shears from their bag in an airport (read: large sharp, knife-like item)

And for the ridiculous person who says "don't you ever make mistakes? don't you understand that TSA employees are human?" Well, let's see... actually no, some things you NEVER make a mistake on, particularly if that's your only job. For example, never have I accidentally gone to my neighbor's house instead of my own. Never in my adult life have I put my shoes on the wrong feet. I don't spell any letters backwards when I write. I don't accidentally break laws like forgetting I'm not supposed to murder someone or steal their stuff. So yes, if your only job is to enforce a finite (they are finite, right?) set of rules, I'm pretty sure you should know each and every one of them. Or that shouldn't be your job.

Anonymous said...

"How many of you out there had to learn the metric system in school only to never use it…"

I'm pretty sure there are plenty of Americans in the U.S.A. who actually use the metric system (SI). Despite that, this article made it easier to determine if it was 3 fl oz. or 3.4 fl oz. (90 mL or 100 mL). Thank-you TSA!

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