🥤 Can you bring Vacuum flask / tumbler on a plane?
Cabin and checked, as long as it is empty
As of 2026-08-21
The rule in detail
The flask or tumbler itself is unrestricted and may go in the cabin or in checked baggage. What is restricted is the liquid inside: with water in it, the 100ml rule applies and security will ask you to empty it. A stainless vacuum wall is opaque to X-ray, so hand inspection is common — arriving with it empty and the lid easy to open is simply faster. Refill it at a water fountain once you are through.
Why the rule is written this way
It is classified as Carry-on or checked because it counts as an ordinary travel item, so there is no restriction on where it goes.
Either bag is fine. If its shape is the kind that invites a question at the checkpoint, keep it in an outer pocket of your cabin bag so you can produce it quickly.
The rules this verdict comes from
The verdict above follows from 1 Korean rule listed below, named in the original Korean because that is how they are indexed at the national law database. These are the rules themselves, not an airline summary — when screening staff disagree, this is the text that decides. Rules are amended; anything changed after the review date above follows the original.
What actually happens at the airport
- Check-in desk — this is the point of no return for your suitcase. Anything that may only travel in the cabin cannot be retrieved after this step.
- Security screening — if the X-ray flags a shape, the bag is opened. Most problem items are caught here.
- Extra check at the gate — on some routes there is one more inspection.
Confiscated items are rarely returned. If you are unsure, confirm the specification before you leave home.
A carbonated drink will force its way out as pressure drops — empty the flask completely before you check it
Other items in the same class
The items below are also classified as Carry-on or checked. Quantity and volume limits differ per item, so check each rule separately.
| Item | Rule |
|---|---|
| 🔌 Corded hair straightener / hairdryer | Yes (cabin and checked) |
| ✂️ Nail clippers / tweezers / eyebrow razor | Cabin: yes / checked: yes |
| 💊 Medicine / prescriptions / supplements | Cabin: yes / checked: yes (prescriptions on you) |
| 📷 Tripod / selfie stick | Cabin: yes / checked: yes (length limits apply) |
| 🍜 Instant noodles | Cabin: yes / checked: yes (declare at customs) |
| ☂️ Umbrella / parasol | Cabin: yes / checked: yes (check length for long ones) |
| 🍼 Baby formula / baby food | Cabin: yes / checked: yes (100ml waived with an infant) |
| 🐟 Dried seaweed / dried fish | Cabin: yes / checked: yes (declare at customs) |
| 📷 Photographic film | Cabin advised (checked scanners fog film) |
Trips that pack this item
2 packing lists on this site carry an item governed by this rule. Open one to see what goes in the same bag alongside it.
Frequently asked questions
- Vacuum flask / tumbler — can I take it in the cabin?
- Cabin and checked, as long as it is empty. The flask or tumbler itself is unrestricted and may go in the cabin or in checked baggage. What is restricted is the liquid inside: with water in it, the 100ml rule applies and security will ask you to empty it. A stainless vacuum wall is opaque to X-ray, so hand inspection is common — arriving with it empty and the lid easy to open is simply faster. Refill it at a water fountain once you are through.
- Vacuum flask / tumbler — can I put it in checked baggage?
- Yes. Neither bag breaks the rules, so decide on weight and on whether you will need it right after landing.
- Is there anything else to watch out for with Vacuum flask / tumbler?
- A carbonated drink will force its way out as pressure drops — empty the flask completely before you check it