TSA Liquid Rules

For Australians flying to or through the United States, understanding TSA liquid rules is essential.

The U.S. applies its own strict security standards, which differ from what you may be used to at Australian airports. Not knowing the details can lead to delays at screening—or having to surrender items you’d planned to bring along.

This guide breaks down the TSA’s 3-1-1 rule in simple terms, explains what the TSA considers a liquid, highlights key exceptions, and shares practical packing tips to help you get through security smoothly. 

What Is the TSA 3-1-1 Rule?

The TSA’s 3-1-1 rule sets strict limits on the liquids, gels, and aerosols you can carry in your hand luggage when flying to or through the United States. It’s easy to remember because of the numbers:

3

Each container can hold a maximum of 3.4 ounces (oz), which is about 100 millilitres (ml). For Australians used to metric, think of this as those small travel-sized bottles you often see in chemists or airport shops.

1

All of your liquid containers must fit inside one quart-sized bag. A quart is just under a litre (about 0.95 L), so for practical purposes, Australians can treat it as a standard 1-litre clear resealable bag.

1

You’re only allowed one bag per passenger, no matter how many carry-on pieces you’re bringing.

In short: decant your liquids into 100 ml bottles, place them in a single 1-litre zip-lock bag, and keep that bag ready to present at security. This simple formula helps TSA officers process passengers quickly while keeping the rules uniform.

Packing Tip for Australians

Keep your carry-on hassle-free by making sure all liquid containers are 100 ml or less, packed into a clear 1-litre resealable bag that’s easy to grab at security.

Keep everything together and accessible, and stash larger items like full-size sunscreen or jars of Vegemite in your checked luggage.

Common Mistakes to Avoid

• Forgetting to transfer toiletries into TSA-compliant bottles
• Assuming “solid” items like lip balm or lipstick are restricted (they’re not)
• Packing oversized sunscreen or cosmetic bottles in carry-on
• Mixing duty-free liquids with other items before connecting flights 

Key Exceptions to the 3-1-1 Rule

• Medical needs: prescriptions, contact lens solution, liquid medication (declare at security)
• Baby and infant products: formula, breast milk, baby food, ice packs
• Duty-free purchases: liquids over 100 ml allowed if sealed in tamper-evident bags with receipt
• Reminder: always declare exceptions at the checkpoint

Summing Up

For Australians travelling to or through the United States, knowing the TSA’s 3-1-1 liquid rule is the key to avoiding delays and keeping your essentials with you.

By packing smart—using 100 ml containers, a single 1-litre resealable bag, and checking ahead for exceptions—you’ll breeze through U.S. security with confidence.

A little preparation goes a long way in making your journey smoother and stress-free.