Guide
TSA liquids rule (3-1-1) explained: what you can bring in 2026
Short answer: in your carry-on, every liquid, gel, cream, paste and aerosol has to be in a container of 3.4 ounces (100 ml) or less, and they all have to fit in one quart-size bag. One bag per person. Anything bigger goes in your checked bag.
The main exceptions are medicine, baby formula and breast milk, and duty-free liquids in a sealed bag on an international connection. As of October 2026, TSA hasn't changed the size limit.
The rule fits in three numbers, but the questions it raises don't. Is peanut butter a liquid? Is mascara? What about the ice pack in your lunch bag? Here's the rule as TSA writes it, the exceptions, and TSA's own rulings on the items people argue about at the checkpoint.
The rule, in plain words
TSA lets you carry "a quart-sized bag of liquids, aerosols, gels, creams and pastes" through the checkpoint. Each item has to be in a container of 3.4 oz or 100 ml or less. You can carry as many small containers as fit in that one bag.
Two things catch people out:
- It's the container size that counts, not what's left in it. A 200 ml tube of sunscreen with a little left at the bottom isn't allowed. The label has to say 3.4 oz / 100 ml or less.
- "Liquid" is broader than you think. If you can spread it, pump it, spray it or squeeze it, treat it as a liquid. That includes toothpaste, hummus and peanut butter.
Anything that sets off an alarm during screening gets extra screening, even if it's within the limit. Take the bag out of your carry-on at the checkpoint unless you're in a PreCheck lane (more on that below).
Is it a liquid? TSA's own answers
TSA's "What Can I Bring?" pages give a ruling for each item. These are the ones people ask about most.
| Item | In your carry-on |
|---|---|
| Toothpaste, shampoo, lotion | 3.4 oz or less, in the bag |
| Mascara | 3.4 oz or less, in the bag |
| Sunscreen, perfume, aerosol deodorant | 3.4 oz or less, in the bag |
| Peanut butter | 3.4 oz or less, in the bag |
| Hummus, yogurt, creamy dips and spreads | 3.4 oz or less, in the bag |
| Alcoholic drinks | 3.4 oz or less, in the bag. FAA rules don't let you drink your own alcohol on board. |
| Solid makeup and powders | Allowed. Powders over 12 oz (350 ml) go in a separate bin and may be opened. |
| Solid food | Allowed |
| Wet wipes, baby wipes | Allowed |
| Empty water bottle | Allowed. Fill it once you're through. |
| Ice and frozen liquids | Allowed if frozen solid at screening. If they're slushy or have liquid at the bottom, the 3.4 oz limit applies. |
| Contact lens solution | Over 3.4 oz is allowed as medically necessary, but some solutions set off alarms. TSA suggests checking big bottles. |
On every item page, TSA adds that the final decision rests with the officer at the checkpoint. If you're unsure, put it in your checked bag or buy it after security.
The exceptions
1Medicine
TSA allows "larger amounts of medically necessary liquids, gels, and aerosols in reasonable quantities for your flight". These don't have to fit in the quart bag. The catch: you have to declare them. Tell the officer before screening starts, and put them in a separate bin, along with things like freezer packs, IV bags, pumps and syringes. Liquids for a nebulizer are exempt too.
Officers may test the liquid, but screening "will never include placing anything into" it. If you don't want it X-rayed or opened, say so, and expect other checks instead, such as a pat-down.
2Baby formula, breast milk and baby food
Formula, breast milk, toddler drinks and baby food (including puree pouches) are allowed over 3.4 oz, and don't need to fit in the quart bag. Ice packs, freezer packs and gel packs to keep them cold are allowed too, even without breast milk in the bag. Your child doesn't need to be travelling with you to bring breast milk.
As with medicine, tell the officer at the start of screening and take these items out for separate screening. TSA suggests clear bottles where you can, because liquid in pouches may need extra testing.
3Duty-free on an international connection
Bought a big bottle of something duty-free abroad and connecting onto another flight in the US? You can carry it on if all three are true:
- you bought it internationally and you're flying to the US with a connecting flight
- the shop packed it in a clear, sealed, tamper-evident bag, and the bag hasn't been opened
- you have the original receipt, and you bought it within the last 48 hours
It still has to be screened, and anything that alarms won't be allowed. TSA itself recommends packing big duty-free liquids in your checked bag, even when they're in a sealed bag.
Did the rule change in 2026?
Not the size limit. The rule dates from 2006, after a foiled plot to bring liquid explosives onto planes. In July 2025, a week after ending the shoes-off rule, Homeland Security Secretary Kristi Noem said liquids "may be the next big announcement", and plenty of articles since have said the rule was being scrapped. But TSA's own liquids page, checked on 30 October 2026, still says 3.4 oz (100 ml) per container, in a quart-size bag.
What is changing is how you're screened. TSA is rolling out CT scanners at checkpoints, which make a 3-D image of your bag. With them, you can leave your laptop in your bag, and TSA says its goal is for 3-1-1 liquids to stay in the bag too. That's about whether you take the bag out, not how big the bottles can be.
And in TSA PreCheck lanes, you already don't have to take out your 3-1-1 liquids, your laptop, shoes, belt or light jacket. The 3.4 oz limit still applies.
Packing the bag so you're not pulled aside
- Check the size printed on each container, not how full it is
- Use a clear quart-size bag that closes with everything inside
- Put the bag at the top of your carry-on so it comes out in one go
- Pack medicine and baby milk separately, and tell the officer before screening
- Move anything you're unsure about (big sunscreen, contact lens solution) to your checked bag
- Flying home from abroad? Check the rules where you're departing from. Other countries set their own limits.
This covers US TSA checkpoints. Rules are set by each country, and the TSA officer has the final say on any item. Check tsa.gov's "What Can I Bring?" tool for anything not listed here.
Questions people ask
Can I bring a half-empty large bottle if there's less than 3.4 oz left in it?
No. The limit is on the size of the container, not how much is inside. A 6 oz bottle with 2 oz left in it still goes in your checked bag. Decant into a travel bottle instead.
Can I bring an empty water bottle through security?
Yes. TSA allows empty bottles in carry-ons. Fill it up at a fountain once you're through the checkpoint.
Does the 3-1-1 rule apply to checked bags?
No, checked bags have no 3.4 oz limit. The FAA does cap toiletries like aerosols, perfume and nail polish in checked bags at 2 litres (68 fl oz) in total per person, with no single container over 500 ml (17 fl oz).
Do I still need to take my liquids out with TSA PreCheck?
No. In PreCheck lanes you can leave 3-1-1 liquids in your bag, along with your laptop, shoes, belt and light jacket. The size limit itself is the same.
Sources
- TSA: Liquids, aerosols, and gels rule (checked 30 October 2026)
- TSA: Disabilities and medical conditions (medically necessary liquids, PreCheck)
- TSA: Traveling with children (formula, breast milk, cooling packs)
- TSA: Computed tomography
- TSA "What Can I Bring?" item rulings: peanut butter, ice and frozen liquids, contact lens solution, solid makeup, sunscreen, alcoholic beverages, empty water bottle
- Fortune: Homeland Security on shoes and liquids (July 2025)