Yes, you can absolutely bring loose powder foundation on a plane in 2026. According to TSA and international aviation standards, dry powders are not subject to the 3-1-1 liquids rule, meaning you do not have to put them in your clear quart-sized bag. However, there is an important "quantity rule" for carry-on luggage: if you are carrying a container of powder larger than 12 ounces (350 ml)—roughly the size of a standard soda can—you must remove it from your bag at the security checkpoint for separate X-ray screening. This is because dense powders can obstruct the view of other items in the scanner. For standard makeup jars, which are typically much smaller, you can simply leave them in your makeup bag. To prevent a "powder explosion" due to cabin pressure changes, many travelers recommend placing a cotton pad inside the jar to take up extra space and keep the sifter closed. In checked baggage, there are no size or quantity restrictions at all, making it the safer bet for large "pro-size" setting powders.