Yes, you must remove liquids from your carry-on at security
TSA requires you to take out all liquids, gels, and aerosols from your carry-on bag and place them in a separate bin at the security checkpoint. This applies to any container larger than 3.4 ounces (100 milliliters), even if the container is not completely full. The rule exists because these substances can be used to conceal explosive materials.
You do not need to remove liquids from checked baggage — only from carry-on bags. If you pack liquids in your checked suitcase, they can stay there throughout security screening. The 3.4-ounce limit applies only to carry-on; checked bags have no liquid restrictions, though some items like flammables have their own rules.
The TSA calls this the 3-1-1 rule: 3.4 ounces per container, 1 quart-sized clear plastic bag, 1 bag per passenger. All your liquid containers must fit inside a single quart-sized bag, and that bag must be clear so officers can see inside without opening it.
Key Takeaways
- Remove all liquids, gels, and aerosols larger than 3.4 ounces from your carry-on and place them in a clear quart-sized bag at security.
- Liquids in checked baggage do not need to be removed or follow the 3.4-ounce limit, though some items like flammables are still restricted.
- Common items that count as liquids include shampoo, conditioner, lotion, toothpaste, peanut butter, yogurt, and spray deodorant.
- You can bring one clear quart-sized bag per person; if your liquids do not fit, move the extras to checked baggage or leave them behind.
What counts as a liquid, gel, or aerosol
TSA defines liquids broadly to include anything that flows, spreads, or sprays. This covers obvious items like water, juice, and shampoo, but also includes things that are solid at room temperature but flow when heated or squeezed. Peanut butter, yogurt, honey, and jam all count. Toothpaste, deodorant, and lotion count. Spray sunscreen, hairspray, and spray deodorant count.
Solid items do not count as liquids, even if they are wet or sticky. A bar of soap is fine. A tube of lipstick is fine. A stick of deodorant is fine. Mascara is fine. The distinction is whether the substance flows or spreads on its own — if it does, it is treated as a liquid.
Medications in liquid or gel form follow the same 3.4-ounce limit, but you can bring them in a separate bag if you need to. Frozen items are allowed in carry-on only if they are completely solid when you reach the checkpoint; if they have any liquid or gel texture, they must follow the 3-1-1 rule.
How to pack liquids for the security line
Buy a clear quart-sized plastic bag or use one you already have at home. A quart is 32 ounces, so it is roughly the size of a sandwich bag, though slightly larger. Place all your liquid containers inside, making sure each individual container is 3.4 ounces or smaller. The total amount of liquid across all containers does not matter — only the size of each individual container.
Pack your liquid bag where you can reach it easily, usually near the top of your carry-on or in an outside pocket. At the security checkpoint, remove the bag and place it in the bin with your shoes, belt, and jacket. Do not open the bag unless an officer asks you to. After you pass through the scanner, put the bag back in your carry-on.
If you forget to remove your liquids, the officer will catch them at the scanner. You will then have to step aside, remove the bag, and resubmit it. This slows down your line, so removing liquids before you reach the conveyor belt is faster for everyone.
What happens if your liquids are too large
If a container is larger than 3.4 ounces, you cannot bring it in your carry-on under any circumstances. You have three options: move it to checked baggage, buy a smaller container and transfer the liquid, or leave it behind.
Moving it to checked baggage is the easiest option if you are checking a suitcase. Most liquids are allowed in checked bags without the 3.4-ounce limit, though flammable items like lighter fluid and certain cleaning products are prohibited in both carry-on and checked baggage. If you are unsure whether a specific item is allowed in checked baggage, check the TSA website or ask an officer before you pack.
Buying a smaller container at your destination is often cheaper than throwing away a full-sized bottle. Many travelers buy travel-sized bottles at drugstores, fill them from their full-sized bottles at home, and pack those instead. This works for shampoo, lotion, and other toiletries.
Duty-free and airport purchases
Liquids you buy at a duty-free shop or airport store after you pass through security can be brought on the plane in your carry-on, even if they are larger than 3.4 ounces. The store will place your purchase in a sealed, tamper-evident bag. Keep that bag sealed and unopened until you are off the plane.
If you open the bag before boarding or during the flight, the liquid becomes subject to the 3-1-1 rule again, and an officer can confiscate it. Some travelers buy alcohol or perfume at duty-free specifically because they want to bring a full-sized bottle on the plane without the size restriction.
International flights and connecting flights
If you are flying internationally or connecting through another airport, the 3-1-1 rule applies at every security checkpoint. If you buy liquids at duty-free on an international flight and then connect through a U.S. airport, keep the sealed bag closed. If you open it or repack it, you will need to follow the 3-1-1 rule again at the connecting airport.
Some countries have different liquid rules than the United States. If you are flying out of the U.S. to another country, follow U.S. TSA rules for your carry-on. When you arrive at your destination and fly back, follow that country's rules. Check the airport website or your airline's website before you travel if you are unsure.
Frequently Asked Questions
Can I bring a full water bottle through security?
No. An empty water bottle is fine, but a full one must be emptied before you reach the checkpoint. You can fill it at a water fountain or bottle-filling station after you pass through security. Many airports have these stations near the gates.
Does toothpaste count as a liquid?
Yes. Toothpaste is a gel and follows the 3.4-ounce limit. A standard tube of toothpaste is usually 4.6 to 6 ounces, so you would need to buy a travel-sized tube or move it to checked baggage.
What if I have a prescription liquid medication?
Prescription liquids and gels are allowed in carry-on bags and do not have to follow the 3.4-ounce limit. However, you should carry the original prescription bottle with your name on it. If an officer questions it, you can show the label as proof it is medication.
Can I bring baby formula or breast milk?
Yes. Baby formula, breast milk, and baby food are allowed in carry-on bags and do not follow the 3-1-1 rule. You do not need to put them in a quart-sized bag. Inform the officer that you are carrying these items when you reach the checkpoint.
Do I need to remove my liquid bag if I have TSA PreCheck?
No. TSA PreCheck members do not have to remove liquids, shoes, belts, or light jackets from their carry-on bags. You will go through a dedicated PreCheck lane where the screening is faster. You still cannot bring liquids larger than 3.4 ounces in carry-on, but you do not have to remove the bag from your luggage.