The TSA 3-1-1 rule is the single rule that trips up more travelers than any other, and it is simpler than it looks. In your carry-on, every liquid, gel, aerosol, cream, or paste must be in a container of 3.4 ounces (100 milliliters) or less, all your containers must fit inside one quart-sized resealable bag, and you get one bag per passenger. That is the whole rule: 3.4 ounces, 1 bag, 1 passenger. Everything below is the detail that decides your specific item.
Last checked: July 2026 — sourced against the TSA “What Can I Bring?” liquids guidance. Rules change; we re-verify quarterly.
The verdict, in one line
Carry-on: allowed, but only in containers of 3.4 oz / 100 ml or less, all inside one quart bag. Checked bag: no meaningful liquid limit for ordinary toiletries — put the big bottles there. The 3-1-1 rule exists only for the carry-on cabin; your checked suitcase is where full-size shampoo, mouthwash, and sunscreen belong.
What each number actually means
The “3” — 3.4 oz (100 ml) per container. This is the size printed on the bottle, not how full it is. A 6 oz bottle that is half empty is still a 6 oz container and will be pulled, even with 2 oz of liquid inside. Officers judge the container, not the contents. Buy travel-size bottles or decant into ones labeled 100 ml or under.
The first “1” — one quart-sized bag. Roughly 6 x 9 inches, resealable, and transparent. Everything liquid, gel, or aerosol goes inside it and the bag must close. If it does not zip shut, you are carrying too much.
The last “1” — one bag per passenger. Each traveler, including children, is entitled to their own quart bag, which is how families spread toiletries across people rather than bottles.
Is my item a “liquid”? The gray zone
TSA reads “liquid” broadly: if it can be poured, pumped, smeared, sprayed, or squeezed, it counts. That sweeps in a lot of solids people do not expect — peanut butter, yogurt, jam, mascara, deodorant in gel or spray form, and even snow globes. The reliable workarounds are to go solid (bar soap, stick deodorant, and solid perfume are not liquids and skip the bag entirely) or to check the full-size version.
| Item | Counts as a liquid? | Carry-on rule |
|---|---|---|
| Toothpaste, sunscreen, shaving cream | Yes (paste / gel / aerosol) | 3.4 oz max, in the bag |
| Stick deodorant, bar soap, solid perfume | No | No size limit, skip the bag |
| Peanut butter, yogurt, jam, hummus | Yes (spreadable / pourable) | 3.4 oz max, in the bag |
| Mascara, liquid foundation, lip gloss | Yes | 3.4 oz max, in the bag |
| Powders (over 12 oz / 350 ml) | No, but may need extra screening | May be asked to remove for a separate check |
The exceptions: what escapes 3-1-1
Several categories are exempt from the 3.4 oz limit and do not have to go in the quart bag, though you should declare them at the checkpoint and expect extra screening:
- Medications — prescription and over-the-counter liquids, gels, and creams are allowed in “reasonable quantities” above 3.4 oz. Declare them; see flying with medication for the full procedure.
- Baby formula, breast milk, and baby food — permitted in reasonable quantities; you do not need a baby with you to carry breast milk.
- Ice, gel packs, and freezer packs — allowed when needed to keep exempt items like medication or breast milk cold.
The layer TSA.gov skips: airlines and other countries
The 100 ml container / 1-liter bag standard is near-universal across the EU, UK, Canada, and Australia, so a 3-1-1-compliant bag clears most international checkpoints. Two divergences matter. First, some major airports — parts of the UK and EU — have installed next-generation CT scanners and quietly lifted the liquids restriction, letting you leave liquids in your bag; but the old 100 ml rule still applies at airports without the new machines, and you rarely know which you will hit, so pack to the strict standard. Second, duty-free liquids bought after security are allowed over 100 ml but must stay sealed in the tamper-evident bag with the receipt; on a connecting international flight, a second checkpoint may confiscate them, so check your transfer airport’s rules.
Airlines themselves rarely change the liquids rule — that is set by the security authority, not the carrier — but they set the checked-bag weight limits that decide how many full-size bottles you can stash. Confirm your fare’s checked allowance on the airline’s own baggage page before relying on it.
The final word
Follow 3-1-1 and you will almost always clear the checkpoint without a second look. But the officer at the lane has the final say and can deny, test, or require you to surrender any item, even a compliant one. When in doubt, put the liquid in your checked bag.
Related rules: lithium batteries & power banks · sharp objects & tools · flying with medication
FAQ
Does the container have to be full or can it be a big bottle with a little left?
The printed container size is what counts, not how full it is. A 6 oz bottle with 2 oz remaining is still over the 3.4 oz limit and will be removed. Decant into travel bottles labeled 100 ml or less.
Can I bring more than one quart bag if I have a lot of toiletries?
One bag per passenger. Each traveler on your booking — including children — gets their own quart bag, so families can spread items across people. For everything else, use your checked luggage, which has no 3-1-1 limit.
Are frozen liquids allowed through security?
If a liquid is frozen solid at screening, it is treated as a solid and is allowed over 3.4 oz. If it has started to melt and is slushy or partially liquid, it falls back under the 3-1-1 limit.
Do wipes, sticks, and powders count toward 3-1-1?
Wet wipes, solid stick deodorant, and bar soap are not liquids and skip the bag. Powders are solids too, but quantities over 12 oz (350 ml) may be pulled for separate screening.
Is the rule different in Europe or the UK?
The 100 ml / 1-liter-bag standard is the same across the EU, UK, Canada, and Australia. Some airports with new CT scanners have relaxed it, but because you cannot count on which machine you will meet, pack to the strict 100 ml standard every time.