TSA Liquid Rules 2026: The 3-1-1 Rule, CT Scanners & Everything You Need to Know
The TSA liquid rule hasn't fundamentally changed, but what counts as a liquid, what's exempt, and where exemptions actually apply has created enough confusion that most travelers pack their carry-on bags wrong. The 3-1-1 rule still exists. But CT scanning, medication exemptions, and the duty-free alcohol loophole mean the rules are far more nuanced than "one quart bag" in 2026.
This guide cuts through the confusion. It covers what TSA actually enforces, what airports let you bypass the rule, which items are exempt, and what happens when you get stopped.
The Core Rule: The 3-1-1 Standard
The TSA 3-1-1 rule is the foundation of the liquid restriction. Despite over two decades of travel security evolution, TSA still enforces this formula at most major airports:
- 3: Each container holds 3.4 ounces (100 milliliters) or less. This includes travel-size shampoo, lotion, perfume, toothpaste, peanut butter, hummus, and most substances with a consistency thicker than water.
- 1: All containers fit inside one quart-sized clear plastic bag. A quart bag measures roughly 6 inches by 9 inches. You get exactly one bag per person.
- 1: One bag per passenger. You cannot combine multiple bags or ask for exceptions. The officer will ask you for the single bag and inspect it.
TSA agents at checkpoint lanes count containers and weigh them. A container labeled "100ml" but actually containing 101ml gets confiscated. A second quart bag gets rejected. The rule is mechanical and leaves zero room for negotiation at most airports.
What Counts as a Liquid (And What Doesn't)
The definition of "liquid" is broader than you think. TSA classifies liquids as anything with a consistency thinner than a solid paste. This includes obvious items and surprising ones:
Definitely liquids: Water, juice, coffee, alcohol, shampoo, conditioner, lotion, sunscreen, perfume, cologne, deodorant spray, gel, hair gel, wet food (yogurt, peanut butter, hummus), baby food, and baby formula.
Surprising liquids: Aloe vera gel, lip balm, toothpaste (over 3.4 ounces), mascara, liquid eyeliner, and cheese spreads count as liquids. Frozen items are okay until they thaw into liquid form. Creamy items in solid form (like a stick of deodorant) are fine. Spray deodorant is a liquid. Solid deodorant is not.
Not liquids: Solid cosmetics (lipstick, eyeshadow, pressed powder), nail clippers, nail files, deodorant sticks, and dry goods (protein powder, vitamins) do not count as liquids.
When in doubt, assume TSA will classify it as a liquid. Oversizing the product (more than 3.4 ounces) automatically violates the rule.
The Medication Exemption (No Size Limit)
Medications—prescription and over-the-counter—are completely exempt from the 3-1-1 rule. This exemption applies to liquid medications of any size. You do not need to place them in your quart bag. You can bring a full-size bottle of prescription cough syrup, insulin, or liquid vitamins without restriction.
How to pass through security with medications:
- Keep medications in their original labeled containers if possible. If they're in a different container, have a copy of the prescription or the original label available.
- Declare medications to the TSA officer before screening. Tell the officer "I have liquid medications in my bag." They will know what you mean.
- The officer may swab the container or test the substance to verify it is actually medication. This takes 30 seconds. You will not be delayed significantly.
- Once verified, the medication goes back in your bag and you proceed. No quart bag required.
Essential medical devices (EpiPens, inhalers, and emergency medications) are similarly exempt.
Baby Formula, Breast Milk & Baby Food (No Limit)
Baby formula, breast milk, and baby food are exempt from the 3-1-1 rule. You can bring as much as you need for your flight and any connection. No size restriction. No quart bag required.
TSA agents understand that parents traveling with infants need to bring feeding supplies. Expect the officer to:
- Ask you to identify which items are baby liquids.
- Possibly open a container and smell it or test it with a swab to verify it is actually baby formula or food.
- Allow the items through without further questioning.
The testing takes time but is routine. Bring baby items in clearly labeled containers. A bottle labeled "Enfamil 6oz" will be waved through faster than an unlabeled container that "might be formula."
Note: Breast milk expressed before the trip is treated as a liquid under the exemption. Breast milk pumped at the airport after security is allowed on the aircraft as well. TSA updated guidance in 2024 to clarify that mothers can bring as much expressed breast milk as needed.
CT Scanners and the 3-1-1 Rule Bypass
Some US airports now have CT scanning technology (Advanced Imaging Technology) that can detect threats in liquids. At these airports, the 3-1-1 rule is optional. You can leave liquids in your carry-on bag. You do not need to remove them or place them in a quart bag.
Which airports use CT scanning in 2026:
- Denver (DEN) — most PreCheck lanes and main security areas.
- San Francisco (SFO) — pilot program in select lanes.
- Phoenix (PHX) — expanded deployment since late 2025.
- Additional airports are adding CT scanners through 2026, but rollout is slow.
If your home airport has CT scanning, you do not need a quart bag for that flight. However, if you connect through an airport without CT scanning, you will need to comply with 3-1-1 at the connecting airport. Many travelers pack two quart bags to be safe—one for domestic carry-on, one for international flights or connections.
Check the TSA website for your specific airport before your flight. If your airport uses CT scanning, the information is displayed prominently.
Duty-Free Alcohol: The Loophole
Alcohol purchased at duty-free shops after passing through security is treated differently than other liquids. Here are the rules:
- Domestic connecting flights: A duty-free alcohol bottle must be placed in your checked bag for the connecting flight. You cannot carry it through the security checkpoint at the connecting airport.
- International flights: Duty-free alcohol purchased after security is allowed on the aircraft. It remains sealed in the duty-free bag. You cannot open it or consume it until you land.
- Size limit: Alcohol bottles over 5 liters are not allowed in carry-on bags. Bottles over 70% ABV (140 proof) are not allowed in checked bags on passenger aircraft.
- Multiple bottles: You can purchase multiple duty-free bottles but only if you're checking all but one. On your final flight leg, you can have only one duty-free bottle in hand when boarding.
The duty-free loophole works because the alcohol is sealed after purchase and you're not carrying it through security a second time. TSA trusts duty-free retailers to screen the items. This is why many international travelers stock up on alcohol at the airport—it's the only place you can bring a bottle larger than 3.4 ounces on an aircraft.
Tip: If you purchase duty-free alcohol on a connecting flight, ask the retailer for a duty-free sticker or receipt. Some airports require proof that the bottle was purchased after security. Keeping the duty-free bag sealed helps as well.
Gels, Pastes & Cream Ambiguities
Gels and pastes create the most confusion at security. Here are the most common items and what TSA actually requires:
Deodorant: Solid stick deodorant is allowed without limit. Spray and gel deodorant count as liquids and must be 3.4 ounces or less in your quart bag. Antiperspirant gel also falls under the liquid rule.
Hair gel: Hair gel, hair paste, pomade, and wax are all classified as liquids. If your container says more than 3.4 ounces, it needs to go in the checked bag or be left home.
Lip balm: If it's solid (stick), it's allowed. If it's in a tube or pot and has a creamy consistency, TSA may classify it as a liquid. To be safe, pack gel-type lip balms in a checked bag or in your quart bag if you have room.
Sunscreen: All sunscreen—spray, lotion, and gel—counts as a liquid. Only 3.4 ounces is allowed in your carry-on. Many travelers buy full-size sunscreen bottles for their destination rather than traveling with them.
Peanut butter, hummus & cheese spreads: These are classified as food spreads and treated as liquids by TSA. A container over 3.4 ounces must go in checked luggage or your quart bag.
Powders and the New Powder Rule
In 2022, TSA updated powder rules due to detection limitations. Powders over 12 ounces in carry-on bags require additional screening. Powders under 12 ounces are allowed freely. This applies to protein powder, makeup powder, baby powder, talc, and any similar substance.
If your container of protein powder or baby powder is over 12 ounces, expect the following:
- TSA will open the container and test it with a swab.
- The swab is placed in a machine that checks for explosive residue.
- If the test passes, you're allowed to take the powder.
- Screening takes 2–5 minutes.
Pack powders in carry-on bags if they're under 12 ounces. Larger containers should go in checked baggage.
The Consequences of Violating the Liquid Rule
What happens if TSA finds a violation:
- Over-sized container: The item is confiscated. You cannot pour it into a smaller container at security. It's gone.
- Multiple bags: TSA will reject the second bag and ask you to discard the contents or check the bag. Most travelers abandon items rather than check luggage.
- Prohibited liquid: Items like fresh fruit juices or unknown substances are confiscated immediately. No exceptions.
- Repeated violations: TSA does not issue fines for first-time liquid violations. However, repeated violations or attempts to circumvent screening may result in additional inspection or questioning.
The best approach: pack conservatively. Bring a quart bag with fewer items than it can hold. Buy toiletries at your destination if you're unsure of sizes.
Final Checklist for 2026
- Pack a single clear quart-sized bag for liquids unless your airport has CT scanning.
- Each liquid container must be 3.4 ounces (100ml) or smaller.
- Medications and baby formula have no size limit and do not require a quart bag.
- Duty-free alcohol purchased after security is allowed on international flights but must be checked on domestic connections.
- Powders over 12 ounces require additional screening.
- Gel products, hair products, and food spreads count as liquids.
- Tell the TSA officer if you have medications or baby items before screening.
- Check your airport's website to see if CT scanning is available—it may exempt you from the 3-1-1 rule.
Understanding the 3-1-1 rule and its exceptions saves time and stress. Most delays happen because travelers violate the rule or don't know the exemptions. With this knowledge, you'll pack faster and clear security smoother.
FAQ: TSA Liquid Rules
Can I bring a full-size bottle of shampoo in my checked bag?
Yes. The 3-1-1 rule applies only to carry-on bags. Checked luggage has no liquid restrictions by TSA (though airlines may have their own rules for hazardous materials). Pack full-size bottles in your checked bag.
Is hand sanitizer allowed in carry-on?
Hand sanitizer is a liquid and must follow the 3-1-1 rule. A 3.4-ounce bottle of hand sanitizer is allowed in your quart bag. Larger bottles must be checked.
What about poured liquids in small bottles?
If you transfer your own toiletries to smaller bottles, each container still must be 3.4 ounces or smaller. Unlabeled containers are more likely to be confiscated because TSA cannot verify the contents.
Can I bring water through security?
No. Empty water bottles are allowed, but bringing a filled water bottle through security violates the liquid rule. Water counts as a liquid. You can fill your bottle after passing through security.
Are perfume and cologne liquids?
Yes, they are classified as liquids. A 3.4-ounce bottle of perfume is allowed. Travel sizes of cologne are fine. Full-size bottles (over 3.4 ounces) must be checked.