TSA Liquid Rules

Updated August 2026 · Vacation Checklists

Every liquid in your carry-on has to be in a container of 3.4 ounces (100 ml) or less, all of those containers have to fit in one quart-sized clear resealable bag, and you get one bag per passenger. That's the 3-1-1 rule, and the part almost everyone gets wrong is that the number on the container is what counts, not how much is left inside it. A half-empty 8 oz bottle of shampoo gets taken at the checkpoint even though it only holds 4 oz of shampoo.

Not sure about a specific item? Run it through our free TSA item checker before you pack it, not after you're in line.

Updated August 2026. TSA rules change, sometimes without much notice, and the officer at the checkpoint has the final say on any item. Confirm current rules at tsa.gov before you fly.

A note on numbers. No dollar figures on this page. Airport shop pricing and travel-size toiletries vary by terminal and by retailer, and we do not set any of it. What you get instead is the 3-1-1 rule as written, the exemptions that are easy to miss, the surprises that get bags pulled, and how to pack the quart bag so it zips.

The 3-1-1 Rule, Exactly

Three numbers, and each one trips up different people.

The container size is the rule. TSA screens by the labeled or embossed capacity of the container. If the bottle says 8 oz, it's an 8 oz container, and pouring half of it out changes nothing. This is the single most common reason a carry-on gets pulled aside. If you want to bring a partial bottle of something, decant it into a travel bottle that's labeled 3.4 oz or smaller.

The bag has to close. A quart bag is roughly 7 by 8 inches. Officers expect it to seal without straining. If it's bulging open, expect it to get pulled. There's no official rule about how many containers fit, because the bag itself is the limit. Most people manage 6 to 9 travel-size bottles.

Everyone gets their own bag. A family of four can bring four quart bags, which is a genuinely useful amount of liquid. What you can't do is put four people's liquids into one gallon bag and call it even.

Metric shoppers, read this. The 3.4 oz limit exists because it's the closest ounce equivalent of 100 ml, which is the international standard. A bottle sold as 100 ml is fine. A bottle sold as 4 oz (118 ml) is not, even though it looks nearly identical on the shelf. Check the number before you buy the travel-size kit.

Checked bags are a different world. The 3-1-1 rule applies to carry-on only. Full-size shampoo, a liter of contact solution, a big bottle of sunscreen: all fine in a checked bag. Alcohol is the exception with its own limits, covered further down.

What Counts as a Liquid (This Is the Surprising Part)

TSA's category is bigger than "liquid." It covers liquids, gels, aerosols, creams, pastes, and anything that can be spilled, spread, sprayed, pumped, or poured. That definition catches a lot of things people don't think of as liquid at all.

Foods that are legally liquids:

• Peanut butter and any other nut butter
• Hummus, guacamole, salsa, queso
• Yogurt, sour cream, cream cheese, soft cheese
• Jam, jelly, honey, maple syrup
• Soup and broth, including in a thermos
• Canned goods packed in liquid (tuna, fruit, beans)
• Gravy, salad dressing, dips of any kind
• Icing, frosting, and cake batter
• Anything you'd describe as spreadable or scoopable

Solid food follows different rules, which our guide to bringing food through airport security covers.

Toiletries that are legally liquids:

• Mascara, liquid foundation, concealer, liquid eyeliner
• Lip gloss and lip balm in a pot (a solid stick balm is fine)
• Gel and cream deodorant (a solid stick is not a liquid)
• Toothpaste, shaving cream, hair gel, hair spray
• Sunscreen in every form except a true solid stick
• Perfume and cologne
• Contact lens solution (with an important exception below)
• Nail polish and polish remover

Everything else that catches people out:

• Snow globes: the liquid inside counts, so a globe that would fit inside a 3.4 oz container can go in the quart bag. Bigger ones go in checked luggage.
• Aerosols of any kind, including dry shampoo and spray sunscreen
• Wet wipes and makeup remover pads: usually fine, since TSA treats them as damp rather than liquid, though a very saturated pack can be questioned
• Bug spray in a pump or aerosol
• Alcohol-based hand sanitizer: TSA allows a larger container than 3.4 oz for hand sanitizer, currently up to 12 oz per passenger, and it gets screened separately
• Powdered substances over 12 oz (about 350 ml): not liquids, but they get extra screening in carry-on and may need to come out of the bag

The frozen loophole is real. If an item is completely frozen solid when it goes through screening, it's not a liquid. Slushy or partially melted means it's a liquid again and the 3-1-1 rule applies. Ice packs count too, with the same solid-or-nothing test. This works well for a short morning flight and badly for a long connection.

Anything you're genuinely unsure about is worth 20 seconds in the TSA item checker, which is faster than arguing about a jar of hummus at the belt.

TSA Liquid Rules Exemptions Most Travelers Don't Know About

This is the part that actually saves people money and stress. Several categories are exempt from 3-1-1 entirely, meaning reasonable quantities in containers larger than 3.4 oz, and they do not go in the quart bag.

Medications

Both liquid and solid medications are exempt. This includes prescription and over the counter, and it covers the related supplies: gel ice packs to keep insulin cold, IV bags, pumps, syringes, freezer packs, and any accessories they need.

How it works at the checkpoint:

1. Take medications out of your carry-on before you reach the belt.
2. Tell the officer you have medically necessary liquids. Say it out loud rather than hoping they notice.
3. They go in a separate bin, not the quart bag.
4. They may be opened, tested, or screened by other means. You can request that they not be X-rayed and ask for alternate screening instead, which usually means a visual inspection and a swab.

You do not need a doctor's note. TSA does not require prescription labels or documentation for medically necessary liquids. Original labeled containers make everything faster and are strongly recommended for international travel, where destination countries have their own rules, but TSA itself doesn't require them.

Related: our travel document checklist covers the prescription paperwork that some countries do ask for at the border.

Breast Milk, Formula, and Toddler Drinks

Breast milk, formula, toddler drinks, and baby and toddler food (including puree pouches) are exempt from 3-1-1 in reasonable quantities, and here's the part people miss: the child does not have to be traveling with you. A parent flying home alone can carry pumped milk.

Ice packs, freezer packs, gel packs, and cooler bags used to keep these cool are also allowed, and they're allowed even if they're partially melted or slushy, which is a real exception to the frozen-solid rule everywhere else.

The process is the same as medications: remove them, declare them, separate bin, expect screening. Testing may include opening containers or using a bottle liquid scanner. If you'd rather they not be opened, say so, and TSA will do additional screening of you and your other items instead.

Other Medically Necessary Liquids

The exemption isn't just pills and milk. It also covers:

• Contact lens solution when it's medically necessary in a larger quantity
• Liquid nutrition, feeding supplies, and prescribed formula for adults
• Distilled water for a CPAP machine
• Gel or liquid items related to a disability or medical condition

The common thread is "medically necessary in reasonable quantity," which TSA interprets sensibly in practice. The failure mode isn't usually rejection, it's time. Declaring these items adds a few minutes, so factor them into how early you arrive at the airport.

Duty-Free and Connecting Flights

Buying a liter of gin at the airport and then boarding a connecting flight is where a lot of alcohol gets confiscated, and the rule that saves it is specific.

Liquids over 3.4 oz bought at duty-free can go through a security checkpoint again only if:

1. They're sealed in a secure tamper-evident bag (STEB) by the retailer, and the bag is undamaged and unopened.
2. The receipt is visible inside the bag and shows the purchase was made in the last 48 hours.

If you open the bag to check something, or it tears in transit, the contents become ordinary liquids and the 3-1-1 rule applies again. Don't open it until you're at your final destination.

International arrivals into the US are the classic trap. If you land in the US, clear customs, collect your checked bag, and then re-clear security for a domestic connection, that duty-free bottle goes back through a checkpoint. If it's properly sealed in a STEB with the receipt, it survives. If it isn't, your options are to move it into your checked bag before you re-check it (which you can usually do at that point) or surrender it.

Worth knowing: not every country's duty-free uses STEBs the same way, and some destinations don't recognize another country's bags. When in doubt, check your bottle into your checked luggage on the last leg where you have the chance.

The CT Scanner Reality Nobody Explains Clearly

You've probably seen a lane where nobody was pulling out laptops or liquid bags, and then hit a different lane the next week where you had to. Both were correct.

TSA has been rolling out computed tomography (CT) scanners, which produce a 3D image an officer can rotate and inspect. At a CT lane, you can usually leave liquids and laptops inside your bag, which is faster and less annoying. At an older 2D X-ray lane, everything comes out as usual.

Here's the honest version, as of August 2026:

• CT machines are in many major airports, but not in every lane at every airport. A large hub can have CT in one checkpoint and older equipment in another, or CT in some lanes of the same checkpoint.
• The 3-1-1 rule itself has not changed. CT changes how your bag is screened, not what you're allowed to bring. Your liquids still need to be 3.4 oz or less, still need to fit a quart bag.
• Signage and officer instructions at your specific lane override everything, including this article.

There has been ongoing discussion about relaxing the liquid limit as CT deployment expands, and some airports in other countries have moved and then reversed on exactly that. Nothing has changed the US 3-1-1 limit as of August 2026. Pack to the 3-1-1 rule every time, and treat "you can leave it in the bag" as a pleasant surprise rather than a plan.

Practical takeaway: keep your liquids bag somewhere you can reach in three seconds, even if you're hoping you won't need to. The cost of being ready is nothing. The cost of digging through a packed bag while the line waits is real.

Alcohol Rules by Proof

Alcohol has its own tier system, and it's based on alcohol by volume, not on the type of drink.

Notes that matter:

• The 5 liter limit applies per passenger, and the bottles must be in unopened retail packaging. Homemade spirits and decanted bottles don't qualify.
• Over 70% ABV is banned outright, checked included. That's the reason certain overproof rums and grain spirits can't fly at all.
• FAA rules separately prohibit drinking your own alcohol on board, even if it's legally in your carry-on quart bag.
• Airlines can add their own restrictions, and destination countries have import limits that are entirely separate from TSA. Check both before you buy a case of wine.

Worked Example: Packing Liquids for a One-Week Trip

Here's the real math for a traveler with a carry-on only, flying domestically for seven days.

What's in her regular bathroom bag:

Result: nine containers in the quart bag, which zips flat. The eye drops go in a separate bin and get declared. The shampoo bar and toothpaste tabs aren't liquids at all, so they free up two slots for anything else.

What she saved: four full-size containers that would have been surrendered at the checkpoint, plus the 10 minutes of a bag search, plus the specific misery of replacing sunscreen at an airport shop, which is the single worst place in the world to buy sunscreen.

The solid-swap trick generalizes well. Bar shampoo, conditioner bars, solid sunscreen sticks, toothpaste tabs, stick deodorant, and solid perfume are all not liquids, which means they don't touch your quart bag at all. Our packing list generator builds this out for your trip length automatically.

What Happens If You Get It Wrong

The realistic outcome is boring, and that's worth knowing.

Your bag gets pulled. The officer opens it, finds the oversize bottle, and gives you options. Depending on the airport and the timing, those usually include: surrender the item, return to the lobby and check the bag, take it back to someone seeing you off, or mail it from an airport shipping counter if one exists.

You surrender the item. You do not get a fine for an honest liquid mistake. Bringing a 6 oz lotion is not an offense, it's just a thing you can't take past the checkpoint. Surrendered items are disposed of, not stored, so there's nothing to reclaim later.

Time is the real cost. A bag search costs 5 to 15 minutes and it happens at the worst possible moment. Two or three flagged items in a family's bags can turn into half an hour.

Where it stops being routine: deliberately concealing a prohibited item, or bringing something genuinely dangerous, is a different situation with real civil penalties. That's not a shampoo bottle. Honest mistakes with toiletries get handled at the belt and forgotten.

One more small thing: an empty water bottle is always allowed. Fill it after security at a fountain or bottle station. Over a family of four that is four bottles of airside water you never buy, on every single flight, and airside water is priced the way airside anything is priced.

Frequently Asked Questions

What is the TSA liquid size limit?

3.4 fluid ounces, which is 100 ml, per container. That's the size of the container itself, printed on the bottle, not the amount of liquid in it. All containers must fit in one quart-sized clear resealable bag, one bag per passenger.

Can I bring liquids on a plane in my checked bag?

Yes, with almost no restrictions. The 3-1-1 rule applies to carry-on only, so full-size shampoo, sunscreen, and contact solution can all go in a checked bag. The main exceptions are alcohol over 70% ABV, which is banned entirely, and spirits between 24% and 70%, which are capped at 5 liters per passenger.

Does the 3-1-1 rule apply to medication?

No. Medically necessary liquids, including prescription and over the counter medications, are exempt from both the 3.4 oz limit and the quart bag. Take them out of your bag, tell the officer you have medication, and put them in a separate bin. You don't need a doctor's note, though original labeled containers help, especially internationally.

What is the travel size of liquids I should buy?

Look for containers labeled 3.4 oz, 100 ml, or smaller. Be careful with 4 oz bottles, which look nearly the same on the shelf and are over the limit. Refillable silicone travel bottles in the 2 to 3 oz range are the reliable option, since the printed size is what gets judged.

Can I bring a full-size stick deodorant?

Yes. Solid stick deodorant isn't a liquid, gel, or aerosol, so there's no size limit and it doesn't go in your quart bag. Gel deodorant, cream deodorant, and aerosol spray deodorant all do count as liquids and follow the 3-1-1 rule.

Do liquids still have to come out of my bag at security?

It depends on the lane. At checkpoints with CT scanners, liquids and laptops can usually stay in your bag. At older X-ray lanes, they come out. CT is in many major airports as of August 2026 but not in every lane at every airport, so follow the signs and the officer's instructions at your specific lane. Pack your quart bag somewhere easy to reach either way.

Can I bring duty-free alcohol through a connecting flight?

Yes, if it's still sealed in the retailer's tamper-evident bag with the receipt visible inside, dated within the last 48 hours. Open or damaged bags lose the exemption and the bottle becomes an ordinary liquid subject to 3-1-1. If you're clearing customs and re-checking bags on a US connection, moving the bottle into your checked bag is the safest play.

What happens if TSA finds an oversize liquid in my carry-on?

Your bag gets opened and searched, and you'll be offered the choice to surrender the item, check the bag, or hand it to someone outside security. There's no fine for an honest liquid mistake, and surrendered items are disposed of rather than held. The cost is time, usually 5 to 15 minutes, which is why it's worth checking before you leave home.

Sort the questionable items first, then pack. Our TSA item checker answers the specific "can I bring this" questions in seconds, the packing list generator builds the rest of your bag around the 3-1-1 rule, and the carry-on size checker confirms the bag itself will fit before you get to the gate.