Yes, you can travel with powdered milk, but it is subject to specific TSA and international security rules regarding powders. For domestic US flights, powdered milk in your carry-on that is larger than 12 ounces (350ml)—roughly the size of a soda can—may be subject to additional screening at the checkpoint. Security officers may ask to open the container or use an X-ray to ensure the substance is safe. To make the process smoother, it is recommended to keep the powdered milk in its original, unopened packaging or a clear, labeled container. If you are traveling with an infant, powdered baby formula is considered a "medically necessary liquid/powder" and is exempt from the standard 3.4oz liquid rule; however, you should still inform the officer at the start of screening. For international travel, be aware of customs regulations; many countries (like Australia or those in the EU) have strict rules about importing dairy products to prevent the spread of animal diseases, so always declare it on your customs form to avoid fines.