Can I Bring Liquids on a Plane?

Key restrictions

Carry-on containers limited to 3.4oz (100ml) each, regardless of how full they are.

All carry-on liquids must fit in one quart-size (about 1 liter) clear resealable bag.

One liquids bag per passenger, removed from your bag at screening unless told otherwise.

Medications, infant formula, and breast milk are exempt in reasonable quantities — declare them at the checkpoint.

Duty-free liquids are allowed past the limit only in a sealed tamper-evident bag with receipt.

Checked luggage has no general liquid size limit (alcohol and aerosols have their own rules).

Why this matters

The liquids rule is the single most common reason travelers lose items at security. It was introduced in 2006 after a plot involving liquid explosives, and it has been enforced at virtually every airport in the world since. Because the rule applies to the container size, not the amount inside, travelers are routinely surprised when a nearly empty full-size shampoo bottle gets pulled.

If you pack carry-on only, this rule shapes your whole toiletry bag. If you check a bag, most of the problem disappears.

Restrictions

In carry-on baggage, the 3-1-1 rule applies:

3.4oz (100ml) maximum per container.
1 quart-size clear, resealable bag holds all of them.
1 bag per passenger.

The main exemptions are medically necessary liquids, infant formula, breast milk, and baby food, which may exceed 100ml in reasonable quantities. Tell the officer at the start of screening; expect the items to be inspected separately.

Duty-free purchases above 100ml can travel in the cabin only when sealed in the store's tamper-evident bag with the receipt visible — and connecting through another country can still get them confiscated at a second screening.

Checked luggage is far more forgiving: ordinary toiletries and drinks have no general size cap, though alcohol over 24% ABV and aerosols carry their own limits.

Some airports with newer CT scanners now let liquids stay in your bag or trial larger limits, but rules differ airport by airport — pack to the 100ml standard and you will clear security anywhere.

What the official guidance says

TSA's liquids rule page sets out the 3-1-1 framework and lists the medical and infant exemptions, noting that exempt liquids must be declared and may be screened separately. The final decision on any container always rests with the officer at the checkpoint, so when in doubt, check it or leave it.

Frequently asked questions

Does the 3.4oz limit apply to the container or the contents?

The container. A half-empty 6oz bottle fails screening even though it holds less than 3.4oz of liquid. Decant into travel-size bottles of 100ml or less, or put the full-size bottle in checked luggage.

What counts as a liquid at security?

Anything you can pour, pump, spread, or spray: drinks, creams, gels, pastes, aerosols, and many foods like yogurt, peanut butter, and soup. If you can squeeze it out of the container, assume the 3-1-1 rule applies.

Can I bring a full water bottle through security?

Not full. Empty bottles of any size are fine, and you can refill them after the checkpoint. Water bought inside the secure area can be carried onto the plane normally.