What are the new TSA powder rules for flights?

U.S. security officials will require more screening of powdered substances in carry-on bags on international flights headed to the United States starting June 30.

A Transportation Security Administration spokesman said Wednesday that the change applies to more than 350 milliliters of powder, about the same as a soda can.

Passengers carrying larger amounts of powders including food, ground coffee or cosmetics could have their bags opened and the powder subjected to a test for explosives. TSA says it already requires the extra screening before domestic flights.

American Airlines is telling international passengers who have more than a soda-can amount of powder to put it in checked baggage, which undergoes more sophisticated scanning to detect explosives. TSA wants to expand CT technology to airport security checkpoints where carry-on bags are screened.

The Transportation Security Administration has been focusing on containers of powders at checkpoints since last summer.

So who will this impact?

According to USA Today, the TSA will request foreign airports with non-stop flights to the U.S. to start taking a closer look at powders starting on June 30. That'll be everything from cosmetics to baby power to protein or energy mixes.

The main security concern is from improvised explosives, but the TSA is also concerned about powdery substances that might be a hazard, like fentanyl or pepper spray.

TSA officials told USA Today this isn't a ban, but they gave this example, they don't want travelers returning with a large container of Moroccan spice in a carry-on bag rather than checked luggage and a checkpoint officer throws away the powder before the person boards the plane.

KGO-TV contributed to this report.