Don't Lose Your Cosmetics at the Airport — The 100ml Rule Is About the Bottle, Not the Liquid
I had a lotion confiscated at airport security once. I'd packed it in my carry-on, and it got caught at the screening line. The frustrating part? The bottle was still pretty full. It was a fairly expensive lotion, so it really stung to just toss it. I ended up buying a new one once I got to my destination.
It turned out the issue wasn't how much was left inside — it was the bottle itself. It was a 120ml bottle. I hadn't traveled abroad much back then, so I had no idea about the 100ml limit. If the bottle says 120ml, it's out. Doesn't matter how much is left inside.
But here's the thing — if you put it in your suitcase as checked baggage, you can bring liters of liquid without any problem. If you're reading this, don't make my mistake. Big bottles go in your suitcase as checked baggage!
There are way more things classified as "liquid" than you'd expect, beyond just lotion and cosmetics. So here's everything I dug up, so you don't end up panicking at security.
The 100ml rule is based on what's printed on the bottle
For people heading abroad for the first time — you might think "if there's less than 100ml inside, I'm fine." Not the case. The label on the bottle is what counts. A 120ml bottle with only 30ml left is still confiscated. Same with a 200ml shampoo bottle that's nearly empty.
Why so strict? Because security officers can't open and measure every bottle. They make the call based purely on the printed capacity. So if the bottle itself exceeds 100ml, nothing inside it matters — it's out.
The fix is simple. Either pack it in your checked baggage, or transfer it into a sub-100ml travel bottle. You can grab travel bottle sets at any Daiso or beauty store and decant your products into them. Big bottles are non-negotiable, no matter how empty — small containers are the only way through.
You need to meet 3 conditions at the same time
Just keeping bottles under 100ml isn't enough. There are three rules you need to satisfy simultaneously.
- Each container 100ml or less — required
- All contained in one clear zip bag of 1L or less — about 20cm x 20cm in size
- One zip bag per person — multiple bags aren't allowed
Break any one of these and the items can be confiscated. Even if you've nailed the under-100ml rule, skipping the zip bag can still get you caught. At the security check, pulling out the zip bag and showing it separately speeds things up.
A lot more things count as "liquid" than you'd think
There are more "liquids" than people realize. Not knowing this is how you get blindsided at security.
Sheet masks, sunscreen, lip gloss, mascara — all liquids. Sheet masks especially trip people up when they get tossed casually into a bag. Surprisingly, gochujang, doenjang, honey, jam all fall under "gels" and follow the exact same 100ml rule. I've seen people get pulled aside heading to Southeast Asia with gochujang. Toothpaste and shampoo — obviously liquid.
Solids, on the other hand, have no volume limit. Lipsticks, pressed powders, stick-form products go straight through. There are way more shampoo bars, solid toothpaste, stick-form lotions on the market now — if you switch to those, you skip the 100ml rule entirely. If only I'd known about travel stick lotions back then, I wouldn't have lost mine.
Medications are an exception
Medication is treated differently. Prescription and over-the-counter meds are allowed even if over 100ml. That said, liquid medications over 100ml (cough syrup, insulin, etc.) require a prescription or doctor's note. Just declare them separately at the security check.
Pills and capsules aren't liquids, so there's no issue. Motion sickness pills, headache meds — all fine to bring.
Duty-free liquids work differently
This one trips people up too. Once you've gone through departure, liquids bought at duty-free can come on board even if over 100ml. Perfume, liquor, all fine. But there's a catch — they have to stay sealed inside the STEB (Security Tamper-Evident Bag) the store provides.
This becomes critical when you have a layover. If you open that bag before your connecting security check, you'll get flagged. Keep it sealed all the way to your final destination.
So what's the actual plan?
For everyday skincare, decant into travel bottles under 100ml. Daiso has solid travel bottle sets. Larger lotions and shampoos — you're not using them at the airport, so check them in with your suitcase. Checked baggage has no volume limit.
The most common mistake is what I did — tossing the original full-size bottle into the carry-on. No matter how much is left, an oversized bottle has to be tossed. Pack a zip bag in advance, keep prescriptions with your meds, don't open duty-free bags. That's really all there is to it.
One last thing
The 100ml rule is about what's printed on the bottle, not how much is left inside. Like I mentioned, I didn't know this on my early trips and ended up throwing out a perfectly good lotion just to buy a new one overseas.
Big bottles in your suitcase. Anything you need before boarding goes in sub-100ml travel bottles. Just remember meds and duty-free are exceptions.