I know as a fact that I've gotten liquids larger than 3 ounces through the TSA scanner systems (such as sunscreen). I was scolded one time for bringing a shampoo container, but I was still ultimately allowed to bring that container through.

In any case, how often are liquids larger than 3 ounces ultimately confisticated, if I put them in a ziploc bag where they can be clearly seen?

  • 4
    So to clarify, you're asking how to break the law?? My understanding is that it's a legal requirement that you don't take liquids larger than 3 ounces through. I am, however, not American, so am not certain on this.
    – Mark Mayo
    Jun 22, 2012 at 4:27
  • 7
    Arbitrarily imposed and poorly enforced TSA regulations are very far from "the law" -- the worst they'll do is confiscate the offending item. Jun 22, 2012 at 13:15
  • 1
    @jpatokal - related question then
    – Mark Mayo
    Jun 22, 2012 at 21:47
  • 5
    To the close voters - a comment explaining your vote would help us mods a lot.
    – Mark Mayo
    Jun 22, 2012 at 21:48

6 Answers 6


For the most part, the 3.4oz rule isn't strictly enforced, in the sense that they don't normally physically check ever single container you have to make sure that it's less than 3.4oz. If it's significantly larger than 3.4oz they will normally be able to see that on the X-ray, and will physically inspect it.

As an example, I travel with a can of spray deodorant that is around 4oz, but is only labeled with "100g", where other cans of the same product are labeled as "4oz (100g)". To date, having gone through airport security probably over 100 times (incl 5 times in the past 3 days) I've had them manually inspect it exactly twice.

So if what you're traveling with is close to 3.4oz, you're probably fine. However, if they decide to look at it, and it's over 3.4oz, then you'll almost certainly lose it. It's up to you whether it's worth the risk/cost of losing whatever it is you're trying to take through. If it's a 4oz tube of toothpaste it's a different answer than if it's a 5oz bottle of $200 perfume!

  • 1
    Remark: 100g is a measure of mass, not volume. For instance, 100g of Plutonium occupy 0.17oz and 100g of flour occupy 5.7oz. So the label "100g" tells nothing about whether a container can go through TSA. Oct 23, 2017 at 8:05
  • @FedericoPoloni - agreed, but chances are the OP (@Doc) is misreading "100 ml" as "100 mg" as I haven't seen any spray deodorants bottles that are measured in grams.
    – RoboKaren
    Jul 7, 2018 at 9:48
  • Many spray deodorants are labeled in grams. For example, amzn.to/2zgUNi9
    – Doc
    Jul 7, 2018 at 15:35

Simple: Label them as saline solution.

We took our shoes off and placed our laptops in bins. Schneier took from his bag a 12-ounce container labeled "saline solution."

"It's allowed," he said. Medical supplies, such as saline solution for contact-lens cleaning, don't fall under the TSA's three-ounce rule.

"What's allowed?" I asked. "Saline solution, or bottles labeled saline solution?"

"Bottles labeled saline solution. They won't check what's in it, trust me."

They did not check. As we gathered our belongings, Schneier held up the bottle and said to the nearest security officer, "This is okay, right?" "Yep," the officer said. "Just have to put it in the tray."

"Maybe if you lit it on fire, he'd pay attention," I said, risking arrest for making a joke at airport security. (Later, Schneier would carry two bottles labeled saline solution—24 ounces in total—through security. An officer asked him why he needed two bottles. "Two eyes," he said. He was allowed to keep the bottles.)

Travel tip courtesy of security guru and merciless TSA critic Bruce Schneier. Probably not worth trying with a green goopy bottle of shampoo though.

  • 4
    I would think you might get into a lot of trouble for lying
    – Casebash
    Jun 23, 2012 at 11:32
  • 2
    @Casebash In the above story, where is the lie? Reusing old bottles (such as empty saline containers) is called recycling and is environmentally friendly.
    – emory
    Jun 25, 2012 at 23:40
  • That's interesting, given what's happened previously - en.wikipedia.org/wiki/Philippine_Airlines_Flight_434. I'd like to see someone go through with a nicely-shaped bottle of perfume with a sticker on it labelled 'saline solution' though :)
    – Sam
    Nov 28, 2013 at 0:55
  • 1
    I can confirm this answer. I walked through with a full 500mL bottle of it once, and was merely waved through when the agent asked what it was. Generally, if it's medical supplies (such as this), and you don't act too sketchy, the security agent will not bother.
    – Nix
    Feb 25, 2014 at 11:31

The best way for TSA agents (or any other airport security in the world) not confiscating liquids larger than 3 ounces is to not carry them.

You can replace toothpaste by tooth powder.

You can replace shampoo by Aleppo soap.

You can replace shave cream by shave soap (or Aleppo soap if you don't mind travelling light with one multiusage item).

You can replace after shave and deodorant by potassium alum.

  • 3
    So what happens when any given security agent is not familiar with tooth powder and confiscates it as a "mysterious powder"?
    – Freiheit
    Jun 22, 2012 at 21:51
  • 1
    I don't know how to handle arbitrary decisions from security agents. I guess that it depends on the legal status of such agents and on your willingness to impose your rights. No powder (even mysterious one) is on the list of carry-on prohibited items. Mysterious powders may be a problem with custom but not with security.
    – mouviciel
    Jun 23, 2012 at 8:51

They usually tell you to throw them away. I had to throw away a brand new tube of toothpaste that I have mistakenly left in my bag.

But they do miss occasionally, or rather "look the other way", and it happened to me as well a couple of times. I wouldn't count on it. I believe its more of a common-sense-bend-the-rules discretion of an individual officer, rather than a matter of policy. And while common sense is something we all like, it is apparently something frown upon at TSA.

Legally they're required not to let you in with too big a jar of liquids.

  • I for one don't like (other people's) common sense. If there need to be restrictions on liquids (which is debatable), then I would much rather have clear rules than common sense. In practice, the most likely alternative is not between rules and good decision making or freedom, it's between rules and arbitrariness. Bureaucracy is a good thing.
    – Relaxed
    Nov 28, 2013 at 14:25

For short-term travel, I often bring small reusable nondescript containers which can be bought from your favourite make-up store, and fill them with any lotions, ointments, balms, unguents, pastes and other colloids I might need.

Obviously you can't use this method for products which are pressurized (shaving cream/gel), as well as fragrances. For the former, you might consider replacing with soft soap (which works well unless your beard has the density and abrasiveness of a metal brush), and for the latter, non-liquid sticks kind of work.


Unmarked containers that are of reasonable size can get through, too. I've been using Crest toothpaste that comes in a blue plastic flip-top bottle that is 5 or 6 ounces. The label is shrinkwrapped around it, and removing that removes the size marking, making it an unmarked, but oversize, container. I've flown enough to go through three of them in the past few years.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .