Planning a trip to or within the U.S. or Europe? Then it’s time to get familiar with one of the most important — and often overlooked — travel rules: the quart-size liquid bag policy. This guide explains how to pack your toiletries properly and comply with carry-on liquid rules enforced across airports in Western countries.
What Is a "Quart-Size Bag" for Air Travel?
In aviation, a quart-size bag refers to a transparent, resealable pouch that holds small liquid items during security screening. It’s required under the U.S. TSA 3-1-1 rule and similar regulations in the European Union.
While no specific dimensions are legally mandated, a practical quart-size bag typically measures about 6 by 9 inches (15 x 23 cm) when flat. It comfortably fits 6 to 10 bottles (each under 100ml) and must remain slim enough to zip shut without straining.
What Is the 3-1-1 Rule (and Its European Equivalent)?
To enhance passenger safety, most Western airports enforce limits on liquids in carry-on luggage. Here’s how the U.S. 3-1-1 guideline breaks down — and the EU follows suit with similar rules:
- 3 = Each liquid item must be no more than 3.4 oz / 100 ml
- 1 = All containers must fit in one clear, zippered, quart-size pouch
- 1 = Each person may bring only one such pouch
Covered items include liquids, gels, pastes, creams, sprays — think shampoo, sunscreen, face wash, or lip gloss.
What Can You Pack in a Quart Bag?
Your travel-sized toiletry kit might include:
ProductCapacitySuggested ContainerShampoo3 ozSqueezable travel tubeMoisturizer3 ozRefillable TSA bottleSunscreen3 ozTSA-friendly squeeze packToothpaste1 ozTubeFace serumSmallDropper bottleHand sanitizer3 ozFlip-top travel bottle
Tip: Prioritize what you use daily and double-check that the pouch zips closed without bulging.
Common Pitfalls to Avoid at Security
Don’t risk delays or disposal of your items. Avoid:
- Bottles over 100ml, even if partially filled
- Packing more than one quart bag per traveler
- Using opaque, bulky, or rigid cases
- Overstuffing — your pouch must close flat
- Forgetting to declare exempt items like medicine or baby formula
Choosing the Right Bag: Materials That Work
To pass airport checks with ease, your bag must be:
- Fully see-through
- Made from soft, flexible material
- Zipper-sealed (not snap or drawstring)
Best materials include:
- PVC: Clear, durable, and printable
- TPU: Eco-conscious and sleek
- PEVA: Lightweight and cost-effective
Avoid mesh, cloth, or solid-colored pouches that hide the contents.
