TSA 3-1-1 Rule for Toothpasteis important to know before packing your carry-on. Since toothpaste is classified as a gel, it must follow the TSA's liquid restrictions. You can bring toothpaste in your cabin bag only if the tube is 3.4 ounces (100 ml) or smaller and fits inside one clear, quart-sized, resealable bag with your other liquids. Tubes larger than the allowed limit should be packed in checked baggage. Following the TSA 3-1-1 Rule for Toothpaste helps you avoid delays, discarded items, and unnecessary stress at airport security, making your travel experience smoother.