💼 Cabin bag
Empty: permitted. Contains liquid: must be under 100ml or emptied before the checkpoint.
✈️ Hold (checked)
Permitted whether empty or full.
Food flask / thermos
Common questions
Screeners will detect liquid inside the flask on the X-ray and stop you. You will be given the option to drink the contents, pour them out at the checkpoint, or return to check-in to store the flask. A hot drink in a sealed thermos is treated the same as any other liquid over 100ml — it will not be allowed through full.
The empty-is-fine, full-must-comply-with-100ml rule applies across virtually all major regions including the US, EU, UK, Canada, and Australia. Some airports in the Middle East and Southeast Asia use additional liquid screening technology that may test the contents of a flask even when declared empty, so rinsing it out beforehand saves time.
If the X-ray shows liquid inside an opaque flask, a screener may ask you to open it so they can verify the contents or run a trace detection swab on it. This is routine and not cause for concern. An empty, visibly clean flask will rarely be opened.
Empty and rinse your flask at home before you leave, then carry it empty through security. Most major airports have hot water stations or cafes airside where you can fill it after the checkpoint. If you want to carry soup or another drink inside 100ml, use a small flask that holds exactly that amount.
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Browse all Food →Based on official United States security guidelines. Rules vary by airline and route — always verify with your carrier before travel. · Rules last verified May 2026.