Starting June 30, 2018, if you are traveling from an International last-point-of-departure to the U.S., powder-based substances in carry-on baggage greater than 350mL or 12 oz. may require additional screening at the Boarding Gates. Powder-like substances over 12 oz. or 350mL in carry-on that cannot be resolved at the Boarding Gates will not be allowed into the cabin of the aircraft and will be confiscated and disposed of.
For your convenience, place powders in your checked bag.