The TSA 3-1-1 Liquids Rule Explained: What You Can Pack in Carry On
What counts as a liquid, how much you can carry through US airport security, and which items are exempt from the limit.
The short answer: at US airports, liquids, aerosols, gels, creams and pastes in your carry on bag must be in containers of 3.4 ounces (100 milliliters) or less. All of those containers must fit in one clear, quart sized bag, and each passenger may carry one bag. That is the 3-1-1 rule. Larger amounts go in checked baggage.
What 3-1-1 means
| Number | Meaning |
|---|---|
| 3 | Each container holds 3.4 ounces (100 milliliters) or less |
| 1 | All containers fit in one quart sized, resealable bag |
| 1 | One bag per passenger |
The limit applies to the size of the container, not the amount inside it. A 6 ounce bottle that is half empty is still not allowed in carry on luggage.
What counts as a liquid
The rule covers more than drinks. Treat anything you could pour, pump, spread, spray or squeeze as a liquid, including:
- shampoo, conditioner, lotion and sunscreen
- toothpaste, gel deodorant and hair gel
- liquid makeup, mascara and lip gloss
- aerosol sprays
- peanut butter, yogurt, dips and sauces
If you are unsure about a specific item, the TSA website has a search tool where you can type in an item and see whether it is allowed in carry on or checked bags.
Exceptions to the rule
Some liquids are allowed in amounts larger than 3.4 ounces in carry on luggage. You must tell the officer about them at the start of screening, and they will usually be screened separately.
- Medically necessary liquids, such as prescription and over the counter medication, in reasonable quantities for your trip.
- Baby formula, breast milk and juice for infants and toddlers, in reasonable quantities.
- Ice packs and freezer packs used to keep medication, formula or breast milk cool.
You do not need to put these items in your quart bag, but expect additional screening.
Duty free liquids
Liquids bought in duty free shops after security, packed in a secure, tamper evident bag with the receipt and bought within the last 48 hours, are generally allowed on connecting flights in the US if the bag stays sealed. If the bag has been opened or the receipt is missing, the 3.4 ounce limit applies again at your next screening.
Is the rule the same outside the US?
The 100 milliliter limit is widely used around the world, including in the UK and EU, but airports are introducing new scanners that can allow larger containers. Rules differ by airport and can change during rollout, so check the airport you are departing from before you pack. Do not assume the rule at your outbound airport also applies on your return.
How to pack your liquids bag
- Use travel size containers you can refill, and label them.
- Put your quart bag at the top of your carry on so you can remove it quickly if asked.
- Pack solid alternatives where possible, such as bar soap, solid shampoo and stick deodorant, which are not limited.
- Put anything larger than 3.4 ounces in your checked bag.
For the rest of your pre trip preparation, see our international travel checklist.
Frequently asked questions
Can I bring an empty water bottle through security?
Yes. Empty bottles are allowed through screening, and you can fill them after security.
Do I need a specific brand of quart bag?
No. Any clear, resealable bag of about one quart (roughly one liter) works, as long as everything fits and the bag closes.
Are solid items like lipstick or bar soap limited?
No. Solid items are not covered by the liquids rule. Lipstick, solid deodorant and bar soap can go anywhere in your carry on.
Sources
- Transportation Security Administration, liquids, aerosols and gels rule and "What Can I Bring?" item search: tsa.gov