In 2006, the United States, Canada, the European Union, Iceland, Norway and Switzerland began a policy requiring all passengers to adhere to rules regarding the amount of liquid that could be carried on planes. To reduce the risk of having liquid explosives brought on board, all passengers are now limited as to the amount and size of permitted carry-on items, such as cosmetics, toiletries, food and beverages. Since then, many other countries have also enacted the policy.
Travel containers vary by shape, capacity and material. Bottles and jars come in a range of sizes based on the number of ounces they can hold. In the past, most travelers bought round 4- or 8-oz. bottles; however, with restrictions on what you can carry on a plane, 2- and 3-oz. containers have gained popularity. Although most containers are made of tough, reusable plastic, you can also get glass, aluminum or other metal containers.
The size limits on travel containers extends only to carry-on luggage, not to checked luggage. For a checked suitcase, only overall weight and dimension limitations of the bag matter. Liquids, gels and aerosols may only be carried into the cabin of a plane if they are in containers with a capacity of 100 ml or 3 oz. In addition, all the containers must be sealed in a 1-qt. zip-top plastic bag. This bag must seal completely with all the containers inside.
Travel sized bottles and jars may leak, especially when subjected to jostling in a carry-on bag and the increased pressure of flying at high altitudes. In addition, some security agents may confiscate containers that do not have the volume capacity printed by the manufacturers. Although most agents will examine and allow all small containers, a few sticklers will only accept containers imprinted with the size, and they have to be 3 oz. or less.
To prevent leaking, you can seal bottles and jars tightly and place adhesive tape over the tops to prevent them from becoming loose. Most savvy travelers also keep their liquid items sealed in zip-top plastic bags to contain leakage and protect clothing and other contents of their luggage. To insure against agents confiscating unmarked bottles, some travelers have started to carry on only manufactured travel-sized products instead of refillable plastic travel containers.
