Many airports, particularly in the United States, have begun to require passengers to put their toiletries in a plastic bag for security reasons, because the plastic bag allows for easy, clear visibility of its contents. Putting items in a plastic bag will greatly decrease the amount of time spent in airport security, and in some cases, toiletries will not be allowed on the aircraft if they are not bagged. In areas where security is tight or personnel are concerned about a threat, toiletries packed in this way may be the only thing you are permitted to bring on board an aircraft, and you will be notified of this at the check-in counter so that you can arrange your checked luggage.
In addition to putting toiletries in a plastic bag, you must also make sure that the amounts are not over the limits set by the Transportation Safety Administration (TSA). Any type of liquid, from sunscreen to mascara, must be 3.4 ounces (100 ml) or less, as larger amounts raise concerns about explosives. Most travelers use travel size containers if they will urgently need a toiletry on the plane, and will check the rest for collection at their destination.
When packing, make sure that the plastic bag also meets TSA requirements. In the United States, a 1 quart (about 1 liter) bag should be used, and everything should fit comfortably and be clearly visible in the bag. If toiletries are tightly packed or obscuring each other, the bag will be subject to inspection by TSA personnel to ensure that it does not contain any contraband items.
Putting toiletries in a plastic bag will allow for a quick transit through airport security, as will other measures like wearing shoes that slip on and off easily, minimizing carry on luggage, and carrying few metal items. If TSA staff do ask to inspect your belongings, be courteous and cooperative so that the process will be short and easy for everyone involved, and repack your toiletries if requested.
While storing toiletries in a plastic bag to board an aircraft may seem onerous, the TSA believes that it reduces the risk of smuggled explosives and other contraband items. Prepare before you get to the airport by packing all of your items neatly and carefully, and make sure that you have room in your checked luggage in case you need to move things around at the last minute: if you are unsure about what types of items are allowed on aircraft, consult your airline.