Liquids, Aerosols & 3-1-1 Rule Hub
The complete reference on 100 ml (3.4 oz) bottle limits, clear quart bag geometry, medical and baby exemptions, and duty-free transit scanning.
1. Interactive 3-1-1 Liquids Volume Checker
Check if your specific container volume (in ml, fl oz, or liters) is legal for carry-on luggage:
💧 3-1-1 liquids rule checker
One quart-size (≈1 L) bag per passenger; every container must be 3.4 oz (100 ml) or less.
Fit is approximate — container shape decides real-world packing. Medically necessary liquids and infant food are exempt: declare them. Packing a whole bag? Plan it container by container →
2. Deconstructing the 3-1-1 Rule
100 ml Container Limit
Each liquid, aerosol, or gel container must be manufactured with a marked capacity of 100 ml (3.4 oz) or smaller.
Clear Zip-Top Bag
All 100 ml bottles must fit comfortably inside one transparent 1-quart (1-liter) resealable plastic bag.
Per Ticketed Passenger
Only one 3-1-1 liquids bag is allowed per traveler in carry-on luggage. Excess liquids must go into checked bags.
3. Statutory Exemptions from the 3-1-1 Rule
Under TSA and CATSA regulations, the following categories are strictly exempt from the 100 ml (3.4 oz) size limit and quart bag requirement in reasonable travel quantities:
💊 Medically Necessary Liquids & Gels
Prescription medications, insulin, saline solution, eye drops, cough syrup, and gel cooling packs used to preserve medication. Declare these items to the screening officer before screening starts.
👶 Baby Formula, Breast Milk & Toddler Juices
Breast milk, infant formula, purified water for baby food, and pureed baby pouches. Allowed even if traveling without your infant. Officers will screen bottles using Bottled Liquid Scanners (BLS).
🛍️ Duty-Free STEB Bags on International Connections
Liquids over 100 ml purchased at airport duty-free shops are permitted on connecting flights ONLY if packed in an unbroken Secure Tamper-Evident Bag (STEB) with the receipt clearly displayed and scanned via an optical liquid scanner.