As part of a broader security push last summer, the Transportation Security Administration began scrutinizing containers of powders in travelers’ carry-on luggage, and the TSA will soon ask foreign airports sending flights directly to the U.S. to do the same, USA Today reports.

The focus is on containers holding at least 350ml of powder – about the size of a can of soda. Last week, TSA and airlines started stepping up awareness efforts about the change, urging passengers to pack larger containers in checked luggage and remove smaller containers from carry-ons for screening, similar to the current guidance for liquids.

The security effort is not a ban, but travelers with large containers of spices, cosmetics, baby power, protein mixes or other powders in a carry-on could risk losing them if a checkpoint officer deems it suspicious. The main concern is from improvised explosives, but TSA is also concerned about fentanyl or pepper spray in the cabin, the article says.