For the better part of two decades, we’ve limited the liquids we carry through airport security. The magic number settled upon was 3.4 ounces, or 100 milliliters, of liquid in a container—an amount that became an international standard developed by explosives experts.
As frequent travelers are well aware, bottles that are 3.4 ounces or less can be stashed into a single one-quart plastic bag, and each traveler is allowed one—in a rule that’s been dubbed the 3-1-1 liquids rule. Oversized liquids can still be packed, but need to go into checked-in baggage.
But as screening devices have become more savvy, there has been talk of those limits being eliminated, especially as a recent report said the UK will scrap the rules by 2024. “The introduction of new technologies has played a significant role in how aviation security has evolved over the past 20 years, thanks to strong industry partnerships and TSA’s agility in adopting technology that enhances security and improves the passenger experience,” a TSA spokesperson says. While there’s no timeline in place yet, the agency “anticipates the limit on liquids will be lifted in the coming years.”
So in the short run, travelers still need to limit the fluids they pack in carry-ons. But, as with all rules, there are exceptions. “TSA requires additional screening to ensure the safety of these liquids,” the spokesperson says of the items. “Travelers in this group should notify security of their medically-necessary liquids.”
In general, those exceptions need to pass a three-prong test. They need to be required during the duration of your flight or at your destination, they can’t be available at the airport in the area past security, and they can’t be available at the destination. But when it comes down to it, the TSA says on its site, “The final decision rests with the TSA officer on whether an item is allowed through the checkpoint.”
Here are some of the most common exceptions of oversized liquids that can be taken through security.
Prescription liquids, creams, and gels
Medication that has been prescribed specifically for you is perhaps the most common item that qualifies as an exception. TSA recommends that it’s clearly labeled so there’s no question about what is inside. “You are responsible for displaying, handling, and repacking the medication when screening is required,” the agency’s site dictates. Depending on the situation, medication can either be screened visually or with an x-ray machine. It may also be tested for traces of explosives.
In some situations where the officers aren’t able to properly screen the item, you may be asked to open the container and transfer it to an empty container to test, or possibly dispose of a small quantity.
In cases where you would like to make sure the medication isn’t opened or X-rayed, simply inform the TSA officer. “Additional steps will be taken to clear the liquid and you will undergo additional screening procedures to include a pat-down and screening of other carry-on property,” the site says.
Liquid medications and contact lens solution
In general, liquid medications that are not prescriptions and contact lens solutions are limited to 3.4 ounces, but TSA does allow “larger amounts of medically necessary liquids, gels, and aerosols in reasonable quantities for your trip,” with the caveat you must declare them to security officers first.
Breast milk and infant formula
Passengers traveling with infants have enough to worry about on their flights—and being able to provide the little ones with the proper nourishment should not be one of those concerns. Technically, TSA categorizes breast milk and baby formula as “medically necessary liquids.” The child doesn’t need to be present for the exception.