Liquid Rules for Carry-On: Containers, Exceptions and Transit

Plan liquids for departure, every transfer checkpoint and the return trip. There is no single worldwide 100ml rule, and an advanced scanner does not by itself establish the permitted volume. Check the airport’s current instructions before packing.

General EU rule: container first, bag second

The European Commission’s general EU-departure guidance allows ordinary liquids in containers of at most 100ml capacity, together in one transparent resealable bag of at most 1 litre. The container’s capacity matters: a half-empty 200ml bottle remains a 200ml container. All containers must actually fit with the bag closed; adding their contents is not a fit test. Use the specified bag rather than buying a larger one when it will not close.

Local example: Heathrow

Heathrow currently allows containers up to 2 litres each and liquids/large electronics to stay in the cabin bag. Empty metal and insulated bottles before its checkpoint; refill after screening where facilities are available. These instructions do not certify another UK airport, your connection or the return journey. Follow checkpoint instructions about separate presentation.

Medicines and baby food

General EU guidance permits essential medicines and baby food/milk above 100ml when needed during the trip; staff may ask for proof and screen them. This is not unlimited quantity, a blanket 350ml insulin limit, automatic acceptance of any supplement or a worldwide prescription rule. Confirm the procedure and keep identifying information available. Security permission is separate from importing medicines into the destination; check the exact product and route.

Duty-free and a second checkpoint

For the EU rule described by Your Europe, the purchase and receipt must remain sealed inside the security bag until the final destination. Security staff may open it for screening; tell them about a further connection so it can be resealed in a new security bag. Do not rely on blue/white bag colour, buying near the gate, or an intact shop bag alone as guaranteed transit acceptance. Check every connecting airport before purchase. See the dedicated transit guide.

Checked baggage has other limits

The cabin screening limit does not make the hold unlimited or every chemical safe. US FAA guidance limits qualifying personal medicinal/toiletry articles, including perfume and sunscreen, to 2kg or 2 litres combined per person and each container to 0.5kg or 500ml; aerosol nozzles need protection. Its checkpoint footnote states the separate US TSA 100ml container restriction. Check operator and route requirements too.

Alcohol is a different category: the cited FAA allowance for unopened retail drinks above 24% and at most 70% ABV is 5 litres per package and 5 litres total per passenger. It is not a 5-litre perfume allowance or universal 1-litre bottle limit. Customs and cabin screening remain separate. Check hazardous products against the exact regulator/operator list instead of putting an uncertain chemical in the hold.

Before leaving, check container labels, the closed bag, identified exceptions, duty-free receipt/seal, leakage protection and each airport’s instructions. Preparation reduces avoidable repacking; it cannot guarantee no extra screening or confiscation.