One of the most common questions asked while traveling — especially when it comes to bringing back souvenirs — is, “wait, am I allowed to take this through security?” The rules are strict and often variable, and it can be difficult to keep up, but it’s worth it if you want to be interrogated or blacklisted. So, from now on, add “powder products” to your don’t-pack-in-my-carry-on list. The Transportation Security Administration will soon implement a new procedure requiring fliers to remove any power substance from their bags, and any amount exceeding 12 ounces will undergo additional screening. If agents can’t identify what the powder is, it might get confiscated.

While the rule will go into effect domestically, TSA is also asking foreign airports with non-stop US flights to implement similar security measures, starting on June 30th. The new procedure is in response to an attempted plot last July to blow up a plane in Australia. Powders have been a concern even before this incident as they make it easier to smuggle improvised explosives, fentanyl, and pepper spray.

The new powder rule comes on the heels of expanded security measures last March which required passengers to remove snacks from their carry-on luggage during security screenings.

So, if you’re trying to bring some spices home from the Middle East, fine sand from the Mediterranean, or if you want to keep yourself looking fresh with some blush and bronzer, it might be safer to check your bag.

H/T: Condé Nast Traveler