The 3-1-1 Rule — In Plain English
The TSA liquids rule is simple once you break it down:
- 3.4 oz (100ml) — Each liquid container must be 3.4 oz or smaller
- 1 quart-sized bag — All liquids must fit in one clear, zip-top quart bag
- 1 bag per person — Each traveler gets one quart bag
💡 Quick check: If your bottle is bigger than 100ml — even if it's mostly empty — it will be confiscated at security. Buy travel-size or use refillable bottles.
What Counts as a Liquid?
More things than you'd expect. The TSA defines "liquids" broadly to include:
- Water, juice, soda, coffee, alcohol
- Shampoo, conditioner, body wash
- Toothpaste, mouthwash
- Sunscreen and lotions
- Makeup: foundation, mascara, lip gloss, concealer
- Gel deodorant (stick deodorant is fine)
- Hair gel, mousse, hairspray
- Peanut butter, jam, hummus, yogurt
- Snow globes (yes, really)
⚠️ Surprising ones: Peanut butter, hummus, salsa, and jam are all considered liquids by TSA and must follow the 3-1-1 rule if in your carry-on.
What Is NOT a Liquid (and Can Go in Your Carry-On Freely)
- Solid deodorant (stick or powder)
- Bar soap and solid shampoo bars
- Powder makeup (eyeshadow, blush, powder foundation)
- Solid lip balm (ChapStick, etc.)
- Dry food items (nuts, crackers, granola bars)
- Solid perfume
What's Exempt from the 3-1-1 Rule
Some liquids are allowed in larger quantities and don't need to go in your quart bag:
- Medications — prescription and OTC, in reasonable quantities. Declare them at screening.
- Baby formula and breast milk — reasonable quantities, even without a baby present.
- Baby food and juice — for infants and toddlers.
- Insulin and other medical liquids — must declare and may require documentation.
Tips to Get Through Security Faster
- Put your quart bag on top of your carry-on so it's easy to pull out at the checkpoint
- Use TSA-approved reusable travel bottles — 3 oz size fills your quart bag efficiently
- Switch to solid versions where possible: shampoo bars, solid moisturizer, bar soap
- Buy full-size toiletries at your destination and check them on the way back
- If you have a large amount of liquid medication, arrive earlier and use a dedicated lane if available
✅ Pro move: Switch to a solid shampoo bar, solid conditioner bar, and solid moisturizer. You'll free up most of your quart bag for things you can't replace with solid versions.
International Flights: Same Rule?
Most countries follow the same 100ml / 1 liter bag standard (based on international aviation guidelines), but enforcement varies. EU airports, UK, Canada, and Australia all enforce similar rules. Always check specific country rules for your route.
What Happens If You Get It Wrong?
If you bring a liquid that's over 100ml, TSA will ask you to either check your bag, put the item in a checked bag at the gate, or discard it. They will not make exceptions for partially full bottles over the size limit. The safest approach: when in doubt, pack it in your checked bag.