Remember the 3-1-1 rule. Those numbers stand for 3 oz. containers, 1 plastic bag and 1 bag per passenger. The U.S. Transportation Security Administration (TSA) implemented the 3-1-1 rule following the 2006 bomb plot.
Pack cosmetics, including liquids and gels, in the luggage that you are checking if you would rather not carry smaller containers on board. However, if you prefer to have your makeup with you to touch up after a long flight, or if you are concerned about your luggage being lost or delayed and don't want to spend time at your destination trying to replace foundation or mascara, you can bring small portions of those "must-haves" in your carry-on luggage.
Transfer your essential cosmetic liquids into 3 oz. bottles. Place all those 3 oz. or smaller bottles into a quart-sized clear plastic zip-top bag. The TSA allows one bag per passenger.
Place your plastic bag in the bin to go through security screening. The transparent bag makes it easier for customs inspectors to view the items. Once you pass through screening, you may put the plastic bag back into your carry-on luggage.
Buy liquid or gel cosmetics products of any size inside the terminal, once you have passed through the security checkpoint. You can take cosmetics and other items you buy within the secure area of the airline terminal on board the plane without further screening.
