The list of carry-on limits airline passengers can carry in their cabin baggage on international flights — which currently includes liquids, gels, aerosols and creams — will soon include powdered material, the Transportation Security Administration has announced.

The limit on powders to 350 milliliters, or roughly 12 ounces, the size of a can of soda, has been enforced since last summer on domestic flights when the agency began enhanced security screening procedures, including requiring fliers to place all personal electronics larger than a cellphone in a separate bin for screening. Beginning June 30, it will ask international screeners to adopt the limits on powders for fliers coming into the United States.

“These measures are part of T.S.A.’s efforts to stay ahead of threats, keep passengers safe and constantly increase capabilities through a layered approach to security,” Mike England, a spokesman for the agency, wrote in an email.

He identified powders including fentanyl and pepper powder “that could be used to irritate or harm aircraft passengers and aircrew if released during flight.”