According to 2026 TSA and international "3-1-1" guidelines, roll-on deodorant is considered a liquid (or gel/paste). This is because it contains a fluid that can be poured or smeared, unlike a "solid stick" or "dry" deodorant. If your roll-on is larger than 3.4 ounces (100ml), it must be packed in your checked luggage. If it is under the limit, it must fit inside your single, quart-sized clear plastic bag. For "high-value" travel efficiency, many "pro-travelers" switch to solid stick deodorant for their carry-on, as these are classified as "solids" and do not have to be placed in the liquids bag at all. Note that "spray" or "aerosol" deodorants are also strictly part of the 3-1-1 liquids rule. In 2026, even with the rollout of "Next-Gen" CT scanners in many airports that allow liquids to stay in bags, the volume limit (100ml) for roll-ons still applies to the majority of international security checkpoints.