No, carbonated drinks don’t explode on planes. They can fizz over more aggressively than usual when you open them, but the sealed can or bottle itself won’t burst. The lower cabin pressure at altitude makes the CO2 gas come out of solution faster once you crack the seal, which is why your soda might overflow if you open it too quickly. The drink itself is under the same pressure as always inside the sealed container.
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Why Soda Fizzes Over on Planes
Aircraft cabins are pressurized, but not to sea level. Most commercial flights maintain cabin pressure equivalent to 6,000 to 8,000 feet above sea level. At that pressure, the air in the cabin is thinner than it is on the ground.
At ground level, the pressure inside your soda can and the ambient air are roughly in balance. The CO2 dissolved in the liquid stays dissolved because the external pressure keeps it there. In a lower-pressure cabin environment, the moment you crack the seal, the CO2 escapes more aggressively than it would at sea level, because there’s less atmospheric pressure keeping it in solution. The result: a faster, messier fizz when opening.
The can itself doesn’t build up extra pressure. A sealed soda can has the same internal pressure whether you’re at 35,000 feet or at sea level, because the gas inside is already sealed in and doesn’t respond to external pressure changes until you open it. This is why your can won’t spontaneously burst, but it might spray you when you open it.
Why Chip Bags Puff Up (But Soda Cans Don’t)
One thing that does expand visibly at altitude: sealed chip bags and other snack bags with air inside. Those bags have flexible walls, so the lower external pressure lets the internal air push the bag outward. You’ve probably seen this on flights: your bag of pretzels looks like it’s about to pop.
Soda cans are rigid and can withstand the pressure differential without deforming. A 2-liter plastic bottle left on a plane might look slightly more taut at altitude, but it won’t burst either.
Can You Bring Carbonated Drinks on a Plane?
Yes, but the TSA liquid rule applies:
- Sealed cans or bottles bought before security: Must be 3.4 oz (100 ml) or less to go in carry-on. A standard 12 oz soda can is too large. These have to go in checked baggage, or you have to buy after the security checkpoint.
- Drinks bought after security: You can bring any size drink through the gate and onto the plane. Drinks purchased inside the secure area are exempt from the 3-1-1 rule.
- Checked baggage: Any size, any amount. Sealed carbonated drinks are fine in checked bags.
One note for checked baggage: carbonation doesn’t cause cans to explode in the cargo hold, but poorly packed carbonated cans can occasionally leak if the pop-top gets caught on something. Pack them in a sealed bag as insurance.
How to Open a Carbonated Drink on a Plane Without a Mess
- Open slowly. Let the seal break gradually rather than snapping the tab in one motion. Let the pressure equalize before opening it fully.
- Don’t shake it first. Shaking disrupts CO2 bubbles and makes the overflow significantly worse. Let it sit completely still for a minute before opening.
- Keep it cool. Cold drinks hold carbonation better. A warm can releases more CO2 when opened. The drinks on the flight attendant’s cart are typically cold, which is why they usually don’t overflow.
- Use the pour method. If you’re pouring into a cup, pour slowly at an angle. The cup’s surface helps release carbonation before it can overflow.
What About Sparkling Water Bottles?
Same rules as soda. The CO2 comes out faster when you open sparkling water on a plane, but it won’t spontaneously burst. Plastic sparkling water bottles bought before security can’t go through in carry-on if they’re over 3.4 oz. Bring them in checked, or buy a bottle of sparkling water in the terminal.
Frequently Asked Questions
Do carbonated drinks explode on planes?
No. Sealed cans and bottles don’t burst. The lower cabin pressure causes CO2 to escape faster when you open the drink, which can cause overflow, but not an explosion.
Can I bring soda cans in my carry-on?
Only if they’re 3.4 oz or under (which essentially no standard soda can is). A 12 oz can must go in checked baggage. Buy soda after you pass through security to bring it in the cabin.
Why does my soda fizz more on a plane than at home?
The cabin is pressurized to about 6,000 to 8,000 feet above sea level, not to sea level pressure. At that lower pressure, CO2 gas comes out of solution more readily when you open the container, causing faster fizzing.
Can I take a 2-liter bottle of soda on a plane?
Not in carry-on. It’s over the 3.4 oz TSA limit. It can go in checked baggage without any problem. It won’t explode in the cargo hold.