Can You Bring Water on a Plane?
You cannot bring water through TSA security checkpoints (containers over 3.4 oz are prohibited). However, you can bring an empty water bottle through security and fill it at a water fountain or bottle-filling station after the checkpoint. You can also buy water after security and bring it on the plane.
Key Takeaways
- TSA prohibits all liquids over 3.
- Frozen water is technically solid and may pass security if completely frozen, but this is not reliable.
- Prescription liquid medications in reasonable quantities are exempt from the 3.
Explanation
TSA prohibits all liquids over 3.4 ounces (100ml) from passing through security checkpoints. This includes water, regardless of whether it is opened or sealed. The rule stems from 2006 security concerns about liquid explosives. Water purchased before security will be confiscated if you try to bring it through.
The best strategy is to bring an empty reusable water bottle. Most airports have water fountains and bottle-filling stations throughout terminals, especially post-security. Filling your own bottle is cheaper than buying bottled water and more environmentally friendly.
Once past security, you can purchase beverages or fill your bottle and bring them onto the plane. Flight attendants will also provide water during the flight, though staying hydrated on long flights may require more than what is offered. Some airports have filtered water stations that are clearly marked.
Cabin humidity on commercial flights drops to around 10-20%, compared to the typical 30-60% in homes. This dry air accelerates dehydration, and the Aerospace Medical Association recommends drinking about 8 ounces of water per hour of flight time. On a 5-hour transcontinental flight, that means roughly 40 ounces—more than a typical airline service provides. Bringing your own filled bottle ensures adequate hydration.
All liquids carried through security must fit in containers of 3.4 ounces (100ml) or smaller, and all containers must fit in a single quart-sized clear plastic bag. This applies to water, juice, shampoo, toothpaste, and any other liquid or gel. Baby formula, breast milk, and medically necessary liquids are exempt but must be declared to TSA officers at the checkpoint for inspection.
Things to Know
- Frozen water is technically solid and may pass security if completely frozen, but this is not reliable.
- Prescription liquid medications in reasonable quantities are exempt from the 3.4 oz rule.
- TSA PreCheck and Global Entry members follow the same liquid rules.
- Some international airports have different liquid rules—certain European airports now allow liquids over 100ml through security using advanced CT scanning technology.