Liquids in Your Carry-On: The 100 ml Rule Explained Simply

Hardly any rule causes as many surrendered water bottles, perfumes and creams at security as the 100 ml rule. Yet it is simple — once you have understood it. Here is everything you need to know so your carry-on goes through the scanner without discussion.

What does the 100 ml rule actually say?

In the EU (and in most countries worldwide), the following applies to liquids in carry-on luggage:

• Each individual container may hold no more than 100 ml — what counts is the container size printed on it, not how much is inside. A half-empty 200 ml tube will be taken away.
• All containers must fit into a resealable, transparent bag of no more than 1 litre (roughly 20 × 20 cm).
• One bag per person is allowed.

What counts as a liquid?

More than most people think. Alongside water and shampoo, these products also count as liquids or gels:

• Toothpaste, creams, lotions and sunscreen
• Perfume and spray deodorant
• Mascara, lip gloss and liquid make-up
• Chocolate spread, honey, yoghurt and soft cheese — yes, food too
• Snow globes (a classic among confiscated souvenirs)

Solid products such as bar soap, solid shampoo or stick deodorant do not fall under the rule — a simple trick for saving space in the bag.

The most important exceptions

Two categories have special rules that apply even beyond 100 ml:

• Medication you need during the flight — if in doubt, bring a prescription or a doctor’s note.
• Baby food and breast milk, if you are travelling with an infant.

Present both separately at the checkpoint. Duty-free purchases in a sealed bag with a receipt are also permitted — do not break the seal until you reach your destination, especially when connecting.

New CT scanners: is the rule about to go?

More and more airports have modern CT scanners that let liquids and electronics stay in your bag. Do not rely on it, though: the rules differ from airport to airport, and a classic checkpoint may be waiting on the return leg. Our advice: keep packing to the 100 ml rule — then you are on the safe side everywhere.

How to pack liquids cleverly

The biggest stress factor is not the rule itself but rummaging through your bag at the belt. Here is how to avoid it:

• Keep the 1-litre bag within easy reach in the top compartment or front pocket — not underneath your clothes.
• Use travel sizes and refillable silicone bottles instead of original packaging.
• A well-designed toiletry bag makes the difference: the Altair toiletry bag keeps liquids, brush and razor separated and upright — so you find everything in seconds at security.
• In the Altair Original Cabin, the toiletry bag has its fixed place in the organiser compartment: bag out, through the scanner, bag back in. Done.

Pre-departure checklist

• ✔ All containers ≤ 100 ml?
• ✔ Everything in one 1-litre zip bag?
• ✔ Medication and baby food separate and within reach?
• ✔ Bag stowed at the top of your case?

With these four points, security is no longer an obstacle — just a formality on the way to the gate.