TSA Liquid Exemption: What You Can Bring on Planes and How to Avoid Security Issues

When you're flying, the TSA liquid exemption, the set of rules allowing travelers to carry limited liquids in carry-on bags under specific conditions. Also known as the 3-1-1 rule, it's not a loophole—it's a safety standard designed to prevent threats while still letting you bring essentials like toothpaste, lotion, and medication. Most people think it's just about bottle size, but the real trick is understanding how the rules apply to your specific items and what counts as an exception.

The TSA 3-1-1 rule, the standard for carry-on liquids that limits each container to 3.4 ounces (100 milliliters), allows all containers to fit in one clear, quart-sized plastic bag. That’s it: three ounces, one bag, one per passenger. But here’s what no one tells you: prescription meds, baby formula, and insulin don’t count toward that limit. You can bring a full bottle of insulin or a gallon of formula if you need it—you just have to declare it at the checkpoint. Same goes for liquid medications for diabetes, epilepsy, or other chronic conditions. You don’t need a doctor’s note, but having one helps if they ask. And don’t assume your pill bottle with liquid inside counts as a solid—those need to follow the 3-1-1 rule too.

Then there’s the TSA compliant containers, containers specifically designed to meet the 3.4-ounce limit and fit neatly in the clear bag. These aren’t magic—they’re just smaller bottles. But if you’re packing shampoo, you can buy travel-sized ones or use silicone squeeze bottles to avoid leaks. A lot of people waste time because they bring a full-size bottle in their carry-on, thinking they’ll check it later. That’s a mistake. If it’s not in the clear bag and over 3.4 ounces, it gets thrown out—even if it’s sealed. And yes, that includes your favorite face serum or hand sanitizer. You can bring one 12-ounce bottle of hand sanitizer now, but only one, and it has to be screened separately.

What about duty-free liquids? You can bring them on board if they’re in a sealed tamper-evident bag with the receipt inside, and you’re flying internationally. But if you have a layover in the U.S., you’ll need to pack them in checked luggage unless you’re flying direct to your final destination. Same goes for alcohol—anything over 140 proof is banned, and anything over 3.4 ounces needs to go in checked bags, no exceptions.

And here’s the thing: the rules don’t change based on the airline. United, Delta, Southwest—they all follow TSA rules. So if you’re flying out of Chicago, Orlando, or LAX, it’s the same. What changes is how strict the agents are. Some let you slide with a 4-ounce bottle if it’s barely over. Others confiscate it on sight. Don’t gamble. Stick to the limit.

There’s no way around it: if you want to avoid the stress of losing your favorite moisturizer or your kid’s formula, you need to plan ahead. Use a checklist. Buy travel sizes. Keep meds separate. And always put the clear bag where you can grab it fast—no digging through your purse at the belt. The TSA liquid exemption isn’t about restriction—it’s about making security faster and safer for everyone. Get it right, and you’ll breeze through. Get it wrong, and you’ll be standing there while your stuff gets tossed. You’ve got the info. Now use it.

Below, you’ll find real-world guides that show you how to pack liquids safely, handle medication exceptions, and avoid the most common mistakes that turn airport security into a nightmare.