Any passenger on an international flight bound for the United States and carrying 12 ounces or more of cosmetics or talcum powder, dry spices, or protein mix is advised to place powders in checked luggage, as they may be subject to additional security screening. Passengers who do not comply may be subject to additional screening. And if agents can’t identify the substance, it may get tossed in the trash.

TSA’s heightened scrutiny comes after agents foiled a plan last July to blow up an Etihad Airways passenger flight in Australia with a powder-based explosive. TSA spokesman Michael England said that wasn’t the only reason for heightened focus on powders, which have long been seen as a threat when it comes to improvised explosives. Many international airlines started voluntarily screening for powders last year, England told CNN.

TSA has also cracked down on other types of carry-on items in the past year, expanding the list of electronic devices that must be removed from cabin baggage last summer.