The restriction came into effect on June 30, 2018 by the TSA (Transport Segurity Administration), the agency responsible for airport security in the United States... (cmsherbert.blogspot.com) さらに...
A blog post and NOT an official source. Powders are OK except for one obvious one... https://www.tsa.gov/travel/security-screening/whatcanibring/items/baby-powder
https://www.tsa.gov/travel/security-screening/whatcanibring/items/baby-powder