The 3-1-1 Rule Didn't Change. Here's What Actually Did.

Every year brings a headline saying the liquids rule is finally over. Every year, someone reads it, packs a full-size sunscreen, and watches it go into a bin at 5:45 in the morning.

Here's the straightforward version.

The rule stands

The TSA's 3-1-1 rule remains the federal standard at US checkpoints. Each container of liquid, gel, aerosol, cream or paste holds 3.4 ounces (100 ml) or less. All of them fit in one quart-size clear bag. One bag per traveller. Anything larger goes in checked baggage.

That has not changed, and nothing has been announced that changes it.

What did change: the process, not the limit

The confusion is real, and it comes from good news that got over-reported.

The TSA is replacing older X-ray machines with CT scanners, which build a three-dimensional image of your bag. At checkpoints where they're installed, you often no longer need to pull the liquids bag out into a separate bin — the scanner reads through it.

That's a genuine improvement. It's also only a change to how you're screened, not to what you may bring. The 3.4-ounce limit applies either way, and CT machines are at a minority of US checkpoints. Whether your lane has one is not something you can plan around.

The reliable approach, and the one the TSA's own guidance points to: follow 3-1-1 everywhere unless an officer at that specific checkpoint tells you otherwise. The cost of complying is nothing. The cost of gambling is your moisturiser.

Worth knowing regardless

• Security measures the container, not the contents. A half-empty 6-ounce bottle is still a 6-ounce bottle, and it's still refused.
• The definition of "liquid" is broader than people expect. Gels, creams, pastes, sprays and spreadable foods all count. Peanut butter counts. Sunscreen counts.
• Medications are exempt from the volume limit and don't need to fit in the quart bag. Declare them, keep the pharmacy labelling, and bring documentation for anything unusual. Never put essential medication in checked baggage.
• Duty-free liquids are fine in the sealed tamper-evident bag with the receipt inside — but don't open it before your final destination.
• Solid items are not liquids. Anything dry and solid sits outside the restriction entirely.

That last point is the one worth acting on.

If you're flying to or from Australia

The rules differ by direction, and the exception catches people out.

Domestic flights within Australia have no volume limit on liquids, aerosols and gels. Full-size shampoo travels in your carry-on, no bag required. Australians know this; visitors rarely do.

International departures follow the familiar standard: 100 ml per container, all of them inside one transparent resealable bag. Note that the bag is smaller than the US quart size — the limit is a sealed area of roughly 20 by 20 centimetres, one per passenger.

The exception that costs people their sunscreen: the international limit also applies to the domestic leg of an international journey. Fly Perth to Sydney and you can carry what you like. Fly Perth to Sydney as the first leg to Los Angeles and you're on 100 ml from the start.

Powders are regulated separately in Australia on international departures, with organic powders such as coffee, protein powder and baby formula exempt. Solid, dry items like sheets are not affected.

Either way, the outbound rule tells you nothing about the return, and a connection adds a third unknown. On a multi-stop trip, the only regime you can check with confidence is the first one.

The way to stop playing

There's a version of this problem you solve by research before every trip, and a version you solve once.

ÆRA sheets are dry and solid. There is no liquid in your bag to be measured, declared, decanted or confiscated — so it stops mattering which lane you're sent to, whether that airport has finished its scanner rollout, or which country's rules apply on the leg home. The pack goes in the bag and stays there between trips.

That covers the three heaviest liquids most people carry. Shampoo, conditioner and body wash come out of the quart bag entirely, which usually leaves enough room that the rest of your toiletries stop being a puzzle. Twenty-five sheets per pack, each one a full wash, dissolving in seconds into a rich lather at the other end.

You're not managing a rule anymore. You just don't have anything it applies to. If you're going further and trying to travel without a checked bag at all, the toiletry bag is usually where it falls apart — there's more on that in our guide to switching to carry-on only.

Two minutes before you fly

1. Check the official security page for every airport on your itinerary, including the return and any connection. News articles go stale; the official page is the source.
2. Pack as though the strictest applies. You're never penalised for being under.
3. Move whatever you can out of liquids entirely — starting with hair and body care, the heaviest and bulkiest category and the easiest to switch.

The rule is twenty years old and will change eventually. Until it does, the least stressful position is having nothing in your bag that it applies to.

Check the source before you fly

Security rules change, and this page is a summary rather than an official one. For the United States, the current rules are published by the Transportation Security Administration. For Australia, see the Department of Home Affairs guidance on what you can and can't bring through airport security.

Last reviewed: 21 August 2026.

Nothing to declare, nothing to decant. See the Complete Ritual →