The TSA 3-1-1 Liquids Rule Explained: What Actually Gets Confiscated in 2026

The TSA 3-1-1 liquids rule is the single most misunderstood line of fine print in air travel. It has been on airport signage for nearly two decades, and still — every day — around 3,000 U.S. travelers have something confiscated at security because of it. A full-size sunscreen on the way to Hawaii. A jar of honey bought as a gift in Greece. A snow globe from a cruise port. A yogurt the parent forgot was technically a liquid.

I fly roughly 40 times a year for work and travel writing, and I have watched this happen dozens of times. It is never the obvious item — no one tries to bring a 1-liter shampoo through TSA on purpose. It is always the thing the traveler did not realize was a liquid, or a container the traveler thought was under the limit because it was half-empty. The 3-1-1 rule does not care what is inside. It cares what is printed on the label.

This guide is the plain-English, 2026-current explanation I wish every first-time international traveler had before their first flight. It covers what 3-1-1 actually means, what gets confiscated most often, the medical and infant exceptions most people never learn about, and the quiet CT-scanner rollout that is reshaping airport security lines right now. We will also look at how it compares to UK, EU, and Asian rules — because with ongoing travel-industry disruptions in April 2026 (the European jet fuel shortage, Beond Airlines suspending service through October, and a wave of carry-on-only travelers chasing Chase Travel Points Boost deals), more travelers than ever are flying through unfamiliar checkpoints on short notice.

What Is the TSA 3-1-1 Rule? (In 50 Words)

The TSA 3-1-1 rule limits carry-on liquids, gels, aerosols, creams, and pastes to containers of 3.4 ounces (100 milliliters) or less. All containers must fit inside 1 quart-size clear zip-top bag. Each traveler is allowed 1 such bag. Anything larger gets confiscated, even partially empty.

Why TSA writes it as "3.4 oz" not "100 ml"

The International Civil Aviation Organization standard is 100 ml. That converts to 3.3814 fl oz. TSA rounds up to 3.4 for U.S. consumer labeling, but the legal check is still 100 ml. In practice, this means a bottle labeled "3.4 fl oz" is compliant, but a bottle labeled "4 fl oz" is not — even if it is two-thirds empty. Officers do not pour liquid into measuring beakers; they read the number on the container.

The bag size matters as much as the bottle size

A quart is 946 ml, or about 1 liter. The bag must be transparent, resealable, and about the size of a standard sandwich bag. If the zip cannot fully close because you have overstuffed it, the bag is non-compliant — even if every individual container is under 100 ml. This is the rule that catches people carrying "enough bottles for two weeks" into a single zip bag.

Why the 3-1-1 Rule Exists (and Why It Has Not Died)

The rule traces back to August 2006, when UK authorities disrupted a plot involving liquid explosives that were to be smuggled on board transatlantic flights disguised as sports drinks. Within days, U.S. authorities banned all liquids in carry-ons. Six weeks later, TSA introduced the 3-1-1 framework — a compromise between "no liquids at all" and unrestricted travel.

The 100 ml limit was not picked at random. Explosive chemists at the time calculated that a single person carrying 100 ml of a specific liquid explosive could not cause catastrophic cabin damage alone — the risk profile drops significantly below that volume. The quart-bag requirement forces all liquids into a small, inspectable space, which makes manual review fast.

Why it survived when other rules did not

Shoe removal rules changed. Laptop bin rules changed. But 3-1-1 has survived because the underlying chemistry did not change — a motivated attacker still cannot fit enough volume of the relevant chemicals into 100 ml. What is changing (slowly) is detection technology, not the rule itself. Which is why the CT scanner rollout is the biggest story in airport security since 2006. More on that in a moment.

What Actually Counts as a "Liquid"

The TSA's working definition is broader than most travelers realize. If it can be poured, pumped, squeezed, spread, smeared, sprayed, or spooned, it counts as a liquid, gel, aerosol, cream, or paste — and it is subject to 3-1-1.

The rule of thumb: "if it would spill"

Imagine dropping the container. If something would leak, ooze, or pour out, TSA treats it as a liquid. If the container breaks and you would just pick it up, it is a solid. This one mental model resolves 95% of the edge cases people get tripped up on.

The weird cases that still confuse people

Wet wipes are technically a gel-impregnated product, but TSA generally allows reasonable quantities in carry-on. Mascara counts as a liquid (small tubes are usually fine). Deodorant sticks are exempt, but roll-on and aerosol are not. Powdered laundry detergent is fine; liquid detergent is not. Solid food is always fine; wet food with any sauce is not.

The 12 Most Commonly Confiscated Items in 2026

TSA publishes statistics and "prohibited items of the week" on their social accounts. Having tracked them for over two years, here are the items confiscated every single day at major U.S. airports:

1. Full-size water bottles. The number one item. Travelers forget to empty before the checkpoint.
2. Oversized sunscreen. Beach and resort travelers, consistently — Hawaii, Florida, the Caribbean routes are the worst offenders.
3. Peanut butter. Parents with kids, flight attendants on international routes. Peanut butter is a liquid.
4. Yogurt and cream cheese. Airport food bought before security — if you forget to eat it, TSA takes it.
5. Snow globes and decorative water-filled souvenirs. Holiday season spike. Most are well over 100 ml.
6. Full-size shampoo and conditioner. Hotel amenities purchased as gifts. Almost always over 100 ml.
7. Honey, maple syrup, olive oil, and jam. Gifts from travel destinations. Confiscated even when sealed.
8. Hummus, salsa, and hot sauce. Airport-purchased snack trays — especially over 3.4 oz.
9. Perfume and cologne gift sets. Duty-free from an earlier trip, now being carried on again.
10. Homemade sauces. Often carried in mason jars, often well above the limit.
11. Wine and spirits over 100 ml. Note: Southwest and Alaska Airlines now let travelers fly wine free in checked luggage, which is the right solution here — not smuggling bottles into carry-ons.
12. Aerosol deodorant and hairspray. Most travel-size aerosols are still labeled over 100 ml.

Exceptions: Medication, Baby Supplies, and Duty-Free

There are three legitimate exceptions to the 3-1-1 rule. If any of these apply to you, you are allowed to exceed 100 ml — but you must declare them at the checkpoint.

Medication (prescription and OTC)

Liquid medication — prescription or over-the-counter — is allowed in "reasonable quantities for the duration of your trip." No 3.4 oz limit. No quart bag requirement. Declare at the checkpoint, place in a separate bin, and expect extra screening (often a swab test for explosive trace, or a vapor chamber). Insulin, liquid antibiotics, eye drops, contact lens solution, and inhalers all qualify. You do not need a prescription label, but a label speeds up screening.

Breast milk, formula, and infant juice

Reasonable quantities are allowed, regardless of whether the child is present. Breast milk, formula, pumped breast milk in cooler packs, juice for infants, and cooler accessories (ice packs, freezer gels) are all exempt. Declare at the checkpoint; expect a separate bin.

Duty-free purchases (with caveats)

Liquids purchased duty-free after security are exempt — as long as they remain sealed in the STEB (Security Tamper-Evident Bag) with the receipt visible. The STEB must stay sealed until your final destination. If you have a connecting flight in the U.S. and need to re-clear security (common for international arrivals), the STEB is usually still valid, but only if the receipt is from the same day or the previous day. Older receipts invalidate the exemption.

Medical devices and nonstandard items

CPAP machines, nebulizers, prosthetics, and medical cooling packs are all exempt from 3-1-1 but subject to their own inspection routines. Declare at the checkpoint.

How CT Scanners Are Quietly Rewriting the Rules

The biggest shift in TSA liquids rules since 2006 is not a policy change — it is a technology change. Computed Tomography (CT) scanners are replacing the old X-ray machines at U.S. checkpoints. They produce 3D images instead of 2D, which allows security software to identify liquid volume and composition without the traveler removing anything.

At airports with CT scanners (as of April 2026, roughly 35% of U.S. checkpoints), travelers are no longer required to remove their liquids bag from the carry-on. In some lanes, the quart-bag requirement has been quietly dropped — you can put individually-sized containers loose in your bag, and the scanner handles identification.

What has NOT changed

The 100 ml per-container limit is still strictly enforced. CT scanners can measure volume, and anything flagged as over 100 ml gets pulled for manual inspection — and confiscated if the container is indeed oversized.

What HAS changed

• Quart-bag removal: Not required at CT-scanner lanes.
• Laptop removal: Usually not required.
• Shoe removal: Being phased out separately.
• Speed: CT lanes move roughly 30–40% faster than legacy X-ray lanes.

The catch: you cannot tell which lane you will get

CT scanners are rolling out unevenly — major hubs first, smaller airports last. Even within a single terminal, some lanes are CT and others are legacy. Always prepare your bag as if the rule applies. Keep your quart bag packable and accessible, and be ready to remove it if directed.

TSA vs. UK, EU, and Asia Liquids Rules

The 100 ml per-container limit is globally aligned. How the rule is applied varies significantly — and if you are flying internationally, the departure airport's rule is what matters, not your home country's.

United Kingdom

UK airports have been aggressive about deploying CT scanners and, in 2023, started lifting the 100 ml limit to 2 liters at retrofitted airports (Birmingham, London City, Teesside). In mid-2024, the UK Department for Transport reinstated the 100 ml limit at some lanes after scanner reliability issues. As of 2026, assume 100 ml at UK airports unless posted otherwise at your specific checkpoint.

European Union (Schengen)

Strict 100 ml per container, one transparent resealable bag of no more than 1 liter, one bag per passenger. Identical in substance to TSA 3-1-1. Amsterdam Schiphol, Paris CDG, and Madrid Barajas have partial CT rollouts; Frankfurt and Rome Fiumicino still require full compliance. Review our Europe packing list for country-specific travel tips.

Asia

Most East Asian hubs (Tokyo Narita, Seoul Incheon, Singapore Changi, Hong Kong) follow 100 ml strictly, with clear quart-bag inspection at most lanes. Japan requires especially thorough compliance; our Japan packing list and Korea packing list cover the most common confiscations at those airports. Southeast Asian hubs vary — our Thailand and Southeast Asia guides address the regional quirks.

The Middle East and Gulf hubs

Dubai (DXB), Doha (DOH), and Abu Dhabi (AUH) enforce 100 ml strictly but have some of the fastest CT lanes in the world. Duty-free purchases at these airports are especially generous — many travelers buy spirits and cosmetics here on connections. See our Dubai packing list for regional-specific packing guidance.

How to Pack Your Quart Bag Correctly

A compliant 3-1-1 quart bag takes five minutes to assemble. Done well, you never think about it again during your trip. Done poorly, it is the single most likely cause of a checkpoint delay.

Step 1: Inventory

List every liquid, gel, aerosol, cream, and paste you plan to bring. Walk through your bathroom routine mentally: wake up → face wash → moisturizer → sunscreen → deodorant → toothpaste → contacts → perfume. Anything on that list over 100 ml needs a solution (decant, buy travel-size, switch to solid, or check the bag).

Step 2: Decant into 100 ml containers

Buy a set of silicone or BPA-free plastic travel bottles (100 ml, about $8 for a 4-pack). Transfer only what you need for the trip duration — two weeks of shampoo is about 60 ml, not the full 100 ml bottle. Leave 10% headspace for cabin pressure expansion. Label each with a permanent marker.

Step 3: Swap for solids where possible

Solids are unrestricted, so the more liquids you replace with solids, the more space you free up in the quart bag. Shampoo bars, conditioner bars, toothpaste tabs, sunscreen sticks, solid deodorant, and bar soap all bypass 3-1-1 entirely. A shampoo bar alone saves you 50 ml of quart-bag space.

Step 4: Pack into one clear quart bag

A zip-top sandwich bag (quart size, about 7×8 inches / 18×20 cm) works. All containers must fit with the bag fully closable. If the zip bulges, you have too much in it. Each traveler gets one bag — children can have their own. Families cannot consolidate into a gallon bag.

Step 5: Place in an accessible outer pocket

At legacy X-ray lanes, you will remove the bag and put it in a bin. Store it in an external pocket of your carry-on so you do not have to dig through clothes to find it. This is the single biggest time saver at a crowded checkpoint.

The Solid-Alternative Cheat Sheet

Every liquid you replace with a solid is one less item in your quart bag, one less thing TSA can confiscate, and usually lighter and longer-lasting too. Here is the swap list I use for every trip:

If you are committed to carry-on-only travel — see our full carry-on packing list and our detailed guide on how to pack for 2 weeks in a carry-on — solid swaps are the single highest-leverage change you can make. It is how experienced travelers fit two weeks of toiletries into one quart bag.

What Happens If You Forget

You are in the security line. You realize you have a 250 ml shampoo bottle in your carry-on. Options:

Option 1: Return to check the bag

If time permits (ideally 60+ minutes before boarding), leave the line, return to your airline counter, and check the carry-on. This costs a baggage fee at most carriers. Not all terminals allow re-entry — confirm before leaving.

Option 2: Mail it to yourself

Some larger airports (ATL, LAX, JFK, ORD, DFW) have mail-back services or self-service Amazon lockers inside the secure zone. For expensive items (designer perfume, prescription cosmetics), this can be worth the $10–20 shipping fee. Most airports do not offer this.

Option 3: Surrender and accept the loss

This is what most travelers do. TSA discards the item; there is no "return later" option. Items in good condition are often sold through state surplus programs — the agency does not return them to travelers.

Option 4: Consume on the spot

For water bottles and drinks, chug and recycle. For food (yogurt, hummus), eat it. For cosmetics, you cannot apply-and-go reliably — surrender.

PreCheck, Global Entry, and CLEAR — Does It Change the Rule?

Short answer: PreCheck and Global Entry do not change the 3-1-1 rule itself. The 100 ml per-container limit still applies. What changes is the process.

PreCheck

You do not need to remove your liquids bag from your carry-on at PreCheck lanes. You can leave shoes, light jacket, and laptop on/in. But the bottles still must be 100 ml or less. If TSA scans your bag and sees an oversized container, you will be pulled for inspection same as any other traveler.

Global Entry

Global Entry is a customs/immigration program for re-entry to the U.S. It includes TSA PreCheck benefits for domestic flights. Same rule: 100 ml limits unchanged; liquids bag does not need removal; CT-scanner benefits apply where available.

CLEAR

CLEAR speeds up the identity-check portion of security (biometric verification). It does not affect liquids at all — you still go through the same scanner process with the same 100 ml limit. CLEAR + PreCheck is the fastest combination at eligible airports.

The "trusted traveler" tradeoff

For travelers who fly internationally more than 2–3 times a year, Global Entry ($100 for 5 years) is almost always worth it. The TSA PreCheck benefit bundled in means less liquid-bag fumbling, faster lines, and fewer chances of a distracted mistake at the checkpoint. This matters more in 2026 as points programs like Atmos Rewards and Chase Travel Points Boost push more travelers to international routes.

Frequently Asked Questions

⚠️ TSA and international aviation security rules change regularly. Always verify with the TSA website and your departure airport 1 week before your flight. Information last reviewed: 2026-04.