When you're going through airport security on your next vacation or business flight, you might notice that there's a posted rule by the Transportation Security Administration called the 3-1-1 Rule, which dictates how much liquid travelers are allowed in their carry-on bags, but you might not understand exactly what this regulation means for your traveling needs.
The 3-1-1 Rule refers to three core components that govern how many liquids you can bring in your carry-on bags: Each liquid must be in a 3.4-ounce or less container ("3"), all containers must be placed inside one clear quart-sized plastic bag ("1"), and each passenger is only allowed one plastic bag ("1").
In sum, the 3-1-1 Rule states that you can carry as much liquid as can fit inside 3.4-ounce containers that fit inside one plastic quart-sized bag; however, you can carry as much liquid as you feel comfortable carrying in your checked bags as long as these liquids do not violate other TSA regulations that dictate what you can and cannot fly with in general.
How to Pack Your Liquids in Carry-Ons
Whether you're hoping to bring your favorite shampoo or conditioner on your weekend trip or need to take contact solution with you on your flight, you'll need to properly pack liquids to get them through the TSA security checkpoint without hassle.
You'll want to start by either buying travel-size bottles of your favorite products or by purchasing three-ounce empty bottles, which you can find at most supermarkets and home goods stores, and filling them with enough of your favorite products to get you through your trip. Then pack each of these inside a quart-sized ziplock (or other sealable) plastic bag—you should be able to fit four or five.
It's recommended that you pack this bag of bottles in your carry-on last, on top of your clothing and other times, because you'll need to pull the bag itself out and put it in one of the security checkpoint bins to pass through the X-ray machine. You can also stow it conveniently in an outside zip pocket for easy access.
Liquids That Are and Aren't Allowed
You might be surprised to learn that you can actually bring travel-size bottles of alcohol in your carry-on or that you can't carry creamy dips or spread as a snack in your carry-on if it exceeds 3.4 ounces, but knowing these rules will help you avoid additional screening at the TSA checkpoint.
You can bring blenders (with blades removed), alcoholic beverages less than 3.4 ounces that do not exceed 70 percent in alcohol content, baby food, some canned foods, and even live lobsters, but you cannot bring gel heating pads, any wet foods that exceed 3.4 ounces, ice cream of any quantity, or firearms of any type.
For a complete list of all items that are forbidden and permitted through TSA security checkpoints at airports, make sure to check out the TSA website before your flight—you can even snap a picture of an item you're questioning and ask them on the TSA Facebook page whether or not it is allowed.