Can You Bring a Thermos On a Plane? TSA Rules 2024

Traveling with a thermos can be a great way to enjoy your favorite hot or cold beverage on the go. But can you take it with you on a flight? What are the TSA rules for thermoses? And how do you pack a thermos for travel?


  • All types of empty thermoses are allowed in both carry-on and checked baggage.
  • You can fill up your thermos with water, coffee or other drinks after you pass the security checkpoint.
  • A thermos flask filled with solid food is good to go through the security checkpoint.
  • You can take a thermos filled with baby formula or medication through the TSA security, these items are exempt from the TSA liquid rule.

Keep reading to know more about traveling with a thermos in both hand and checked luggage.

Let’s dive right in.

A thermos

Thermos TSA Rules

The Transportation Security Administration (TSA) are the folks that control airport security in the United States.

It’s their duty to prevent any prohibited or dangerous items from getting into the airplanes. They have a list of what you can and can’t bring on a plane, which you can check on their website.

Here is what they have to say about traveling with an empty thermos.

All the marks are green for an empty thermos in both carry-on and checked baggage.

But If you are planning to bring a cold or hot drink on board the airplane, then you need to consider the TSA 3-1-1 liquid rule.

Liquids must be in containers that are 3.4 fl oz (100 ml) or less, placed in a clear quart-sized plastic bag, and each passenger is allowed only one quart sized bag.

This liquid rule applies to hand luggage only.

So, what does this mean for your thermos? It means that you can bring an empty thermos through the security, but not a full one.

You can also bring solid foods in a thermos, as long as they are not soups or stews.

But you can fill your thermos after you clear the security, with whatever you want, either at a water fountain, a coffee shop, or a restaurant.

But wait, there’s more. The TSA has some exceptions to their liquid rule. You can bring liquids over 3.4 ounces if they are:

  • Medications
  • Baby formula, breast milk, or juice for infants or toddlers
  • Frozen liquids, as long as they are completely solid when you go through security

So, if you have a medical condition, a baby, or a frozen drink, you can bring your thermos on a plane with more than 3.4 ounces of liquid.

Just ensure that you inform the TSA officer to have it screened separately.

Can you take a smart thermos in carry-on baggage?

Yes, you can take a smart thermos in carry-on baggage, as long as it is empty or contains only solid foods or liquids that are exempt from the liquid rule.

The advantage of taking a thermos in carry-on baggage is that you can enjoy your drink during the flight or at your destination.

You can also avoid the risk of your thermos leaking or breaking in your checked baggage.

The downside of taking a thermos in carry-on baggage is that you have to deal with the security screening.

You may have to open your thermos and show its contents to the TSA officer. You may also have to wait in line to fill your thermos after security.

And you have to make sure that your thermos fits in your carry-on bag and meets the size and weight limits of your airline.

Can you take a food thermos in checked baggage?

You can take both solid and liquid food thermoses that are larger than 3.4 fl oz in checked baggage, as long as it is sealed and wrapped properly.

The good thing about taking a thermos in checked baggage is that you don’t have to worry about the security screening.

You can pack your thermos with any amount of liquids and you do not have to declare it or show it to anyone. You can also take a larger thermos that can hold extras of your drink.

The drawbacks of taking a thermos in checked baggage is that you can’t access your drink or food during the flight or at the airport.

You also have to trust that your thermos will survive the rough handling of the prompt luggage handlers.

I also searched the TSA social media to find some answers.

Jason (@duvkc) wanted to bring this Yeti empty metal thermos in his carry-on.

The TSA customer service confirmed that empty metal beverage containers are allowed in carry-on bags.

Thanh-Thuy (@snoopybleah) wanted to know if an insulated food thermos is allowed through the TSA security checkpoint.

The TSA team reiterates the same response.

A thermos must be empty from any liquids at the time of the security screening, solid food are good to go through the security checkpoint without any limits

How to pack a thermos for travel

Whether you take your thermos in carry-on or checked baggage, you want to make sure that it is neatly protected.

Here is some tips to consider:

1. Take a thermos that is durable and easy to clean.

You don’t want a thermos that will break, spill, or stain your clothes or other items in your bag.

2. Empty your thermos before you go through airport security.

You don’t want to waste your drink or cause a delay at the security line. You can always fill up your thermos afterward.

3. When packed in your checked bag wrap your thermos in a plastic bag or a towel.

This will prevent any leaks from getting on your clothes or other items in your bag. It will also protect your thermos from scratches or dents.

Last Few Words

It’s all good to bring an empty thermos on a plane, but not a full one.

You can also bring solid foods or exempt liquids in a thermos like medication and baby formula.

Choose a thermos that is durable, leak-proof, and easy to clean, and wrap it and place it in a secure and accessible spot in your bag.

Hope this helps

Happy travels

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