Due to their excellent temperature retention, hydroflasks are a must if you travel often.

So you no doubt want to know if you can bring a hydroflask on your next flight or not.

According to TSA regulations, you can bring a hydroflask on a plane in both your carry on and checked bags, though the hydroflask should be empty if packed in your carry on.

Can You Bring a Hydroflask on a Plane?

Carry on Bags

The TSA have a rule in place called the 3-1-1 Rule.

The 3-1-1 Rule states that passengers are only allowed to bring water, gels and liquids in containers that are no larger than 3.4oz/100ml.

Note that it doesn’t matter how much liquid is inside your hydroflask, it is the size of the hydroflask itself that is important.

So, if your hydroflask is at least 3.4oz/100ml in size, it should be empty.

As the smallest hydroflask you can buy is usually at least 12 ounces in size, this won’t apply.

But it’s good to know the 3.4oz/100ml limit if you want to bring other liquids (as well as gels and aerosols) on a plane.

Checked Bags

You are allowed to pack your hydroflask in your checked bag regardless of how much liquid it contains.

Domestic vs. International Flights

The 3-1-1 Rule is not limited to just flights within and from the USA.

As this rule applies worldwide, it means that you can only bring a hydroflask in your carry on if it is empty.

By Airline

Airlines follow TSA regulations.

This means that you can pack your hydroflask in your carry on if it is empty, and in your checked bags when it is either empty or contains liquid.

Will a Hydroflask Explode on a Plane?

Despite the changes in air pressure when flying, you don’t have to worry about your hydroflask exploding.

We do recommend slowing releasing the pressure by opening it up slowly if you filled your hydroflask before your step onto the plane.

Also, if your hydroflask has a straw and a flip-up mouthpiece, make sure that you slightly twist open the lid a bit before flipping the mouthpiece.

If you do this, the liquid inside the hydroflask won’t turn into a supersoaker and spray on your fellow passengers.

Can You Fill Up Your Hydroflask After Airport Security?

Once you have passed airport security, you are allowed to fill a hydroflask and then bring it onto the plane.

Can You Bring a Water Bottle on a Plane?

You are allowed to bring an empty water bottle on a plane in both your carry on and checked bags.

If the water bottle is larger than 3.4oz/100ml and contains liquid, you are not allowed to pack it in your carry on.

Can You Bring Coffee on a Plane?

According to TSA regulations, you are allowed to bring coffee beans, ground coffee, and single-serve coffee capsules and pods on a plane in both your carry on and checked bags.

We go in much more detail in our can you bring coffee on a plane article.

See Also: What Size Liquid Can You Take on a Plane?