The plan was to smuggle bomb materials onto planes using plastic drink bottles. Since then, the TSA has limited the amount of liquid passengers can bring onto planes to containers no larger than 3.4 ounces, a regulation commonly called the 3-1-1 rule.
Why is it called the 3-1-1 rule?
The 3-1-1 Rule refers to three core components that govern how many liquids you can bring in your carry-on bags: Each liquid must be in a 3.4-ounce or less container ("3"), all containers must be placed inside one clear quart-sized plastic bag ("1"), and each passenger is only allowed one plastic bag ("1").
Why can’t you bring full size shampoo on a plane?
What are the rules for flying with shampoo?
It's called the 3-1-1 liquids rule. Each item must be 3.4 ounces or less and must be able to fit inside a one-quart size clear zip-top bag. The limit is one bag per person. Typically, travelers put their toiletries in the bag such as shampoo, hair products, make-up and toothpaste.
Can I take normal size shampoo in my suitcase?
All liquid toiletry and cosmetic items such as shampoo, sun cream, perfumes and aftershaves in containers over 100 ml must be packed in hold baggage. Where oversize liquids are found inside cabin baggage, passengers will always have to abandon them at security, or make use of a 'mail and fly' service if available.