Easiest Way to Beat Carry-On Liquid Restrictions (100ml Rule)

We’ve all been there. You’re in the airport security line, systematically taking off your belt and shoes, and then you see it: the checkpoint for the 3-1-1 liquids bag. It’s the single biggest point of friction for one-bag minimalist travelers. That feeling of your stomach dropping when the security agent pulls your 40L backpack aside for a manual check is a travel day-ruiner.

This used to be my single biggest headache. After spending the last five years or so refining my minimalist travel system for Travel with dp, I realized that the liquids bag is the final hurdle for true one-bag freedom. My breakthrough wasn’t finding the perfect 100ml bottle; it was realizing, in most cases, I didn’t need the liquid at all. I’ve since developed a “solid-first” toiletries kit that has passed through security in more than 15 countries without a second glance. I’m here to share that tested, practical system so you can skip the trial-and-error (and the security trash bin).

What Exactly Is the 3-1-1 Liquid Rule?

Before we can “beat” the rule, we have to know it inside and out. It’s simple, but the details are what trip people up. The 3-1-1 rule is the name for the security protocol used in the US and adopted by most airports worldwide.

Here’s the breakdown:

• 3: All liquids, gels, and aerosols must be in containers of 3.4 ounces (100 milliliters) or less.
• 1: All these containers must fit into one clear, quart-sized (or one-liter) bag.
• 1: Only one such bag is allowed per passenger.

This bag must be removed from your carry-on and placed in a bin for separate screening. The purpose is to allow security officers to get a clear, quick look at your liquids.

The “Common Culprits” People Forget Are Liquids

The biggest mistake I see (and one I made myself) is misunderstanding what airports consider a liquid. It’s not just water. The rule applies to anything you can spread, smear, spray, or spill.

My mental checklist for “Is this a liquid?” is simple: if it’s not a true, dry solid, it’s a liquid.

Here’s a quick reference I’ve built from experience to help you sort your gear.

The key takeaway is that the container size matters, not the amount of liquid inside. I’ll cover that common mistake a bit later.

The Ultimate Strategy: Replacing Liquids with Solids

Here’s the honest truth: the easiest way to “beat” the 100ml rule is to not play the game at all. My entire travel philosophy is built on removing points of failure, and that 1-quart bag is the weakest link. Every solid item you pack is one less thing to worry about, one less potential spill, and one less item in that cramped plastic bag.

My goal is to get my clear liquids bag as empty as possible. For a two-week trip, I can now regularly travel with only two or three tiny 100ml-or-less items, with the rest of my toiletries being solid. This strategy is the core of minimalist, stress-free packing.

Solid Toiletries That Genuinely Work (My Tested Kit)

I’ve spent years testing solid alternatives. Some are amazing, and some are… not. Here is a breakdown of the items that have earned a permanent spot in my travel kit.

1. Solid Shampoo & Conditioner Bars

This is the biggest game-changer. A single shampoo bar can replace two to three full-sized bottles of liquid shampoo.

• Pros: They last an incredibly long time (often 60-80 washes), they can’t spill in your bag, and they save a huge amount of space.
• Cons: They need to be stored properly. If you pack them wet, they turn into a soggy mess.
• My Experience: I learned this the hard way. My first bar disintegrated in its tin. The trick is to buy a dedicated travel tin or soap dish with drainage. After my shower, I pat the bar dry with a towel before putting it away. This keeps it solid and makes it last.

2. Solid Soap / Body Wash Bars

This one is obvious—it’s the classic bar of soap. But many people still pack liquid body wash. I stick to a simple, scent-free bar.

• Pro Tip: You can find multi-purpose bars that work for body, face, and even shaving. This “all-in-one” approach is the peak of packing minimalism. I look for brands that use natural oils, as they don’t dry out my skin like some hotel soaps.

3. Toothpaste Tablets & Powders

This was the weirdest switch for me, but now I’m a total convert. Toothpaste tablets are small, chewable pellets that you bite down on and then brush with a wet toothbrush.

• Pros: They are incredibly lightweight, and you can pack the exact amount you need for your trip (e.g., 28 tablets for a 14-day trip). They are 100% dry and take up almost no space.
• Cons: The texture is strange at first. It takes a few days to get used to chewing your toothpaste.
• My Experience: I tried three different brands before I found one I liked. Some don’t foam up well. But once I found a good one (look for ones with fluoride, if that’s important to you), I never looked back. It feels fantastic to completely remove the largest tube from my liquid bag.

4. Solid Deodorant

Most travelers already use this, but it’s worth mentioning. A solid stick deodorant does not count as a liquid. However, gel, roll-on, and spray deodorants do. If you use one of those, switching to a solid stick is an easy win.

5. Solid Skincare & Sunscreen

This category has exploded in a great way.

• Solid Moisturizer: These come as bars or in tins (like a hard balm). You rub them on your hands and then apply to your face or body. They are often very concentrated and great for dry skin after a long flight.
• Solid Sunscreen: This is my favorite one. A sunscreen stick is a lifesaver. It doesn’t count as a liquid, it’s easy to apply (and re-apply) on the go, and you don’t have to worry about a greasy 100ml bottle. I carry one in my pocket, not even in my main bag.
• Solid Face Wash: Just like shampoo bars, these are concentrated, long-lasting, and easy to travel with.

A Quick Comparison: Solid vs. Liquid Toiletries

When I’m deciding whether to find a solid alternative, I run through this mental checklist. The benefits almost always outweigh the convenience of liquids.

What If You Must Bring a Liquid?

Sometimes, you just can’t find a solid version. This might be for a specific prescription, a high-end face serum, or a contact lens solution. In this case, your goal is to have the most organized, compliant, and hassle-free 3-1-1 bag possible.

Choosing the Right 3-1-1 Bag

The free Ziploc bag from the airport works, but it’s a terrible long-term solution. They rip, the zipper fails, and they are hard to pack.

After my second Ziploc failure, I invested about $15 in a reusable, TSA-compliant bag. Here’s what to look for:

• Clear Material: It must be transparent. TPU (a durable plastic) is better than flimsy PVC.
• 1-Quart/1-Liter Size: Don’t go bigger. A bag that is clearly over-sized invites scrutiny.
• Good Zipper: A strong, sturdy zipper is non-negotiable.
• Shape: I prefer bags that have a flat bottom and can “stand up” on their own. It makes them so much easier to pack and to use on a hotel counter.

Finding the Best Reusable 100ml Bottles

Stop buying those cheap, hard plastic bottles from the dollar store. They are brittle, they crack, and you can never get the last 20% of the product out.

The answer is silicone bottles.

• They are squeezable, so you can get every last drop.
• They are durable and won’t crack under pressure in your bag.
• They often have wider mouths, making them much easier to fill.

My Pro Tip: You probably don’t need 100ml. For a two-week trip, I found I was only using a fraction of my 100ml bottles. I now use smaller 50ml or even 30ml bottles. They save a huge amount of space in that tiny quart bag. For things like eye cream or a tiny bit of foundation, I use a clean, empty contact lens case. Each side holds a few days’ worth perfectly.

How I Pack My Compliant Liquid Bag (Step-by-Step)

When I do have to carry liquids, I follow this exact process:

1. Audit: I lay out only the absolute essential liquids. I ask myself, “Can I buy this there? Can I live without it? Is there a solid version?”
2. Decant: I fill my silicone bottles. I leave a little air at the top. This prevents them from bursting when air pressure changes on the plane.
3. Label: I use a simple piece of masking tape and a marker to label each bottle. Don’t assume you’ll remember what’s in the blue bottle.
4. Pack: I place the bottles vertically in my clear, stand-up bag. Taller bottles go in the back, shorter ones in the front.
5. Access: This is the most important step. The bag goes in an easy-to-reach outside pocket of my 40L backpack. I never, ever pack it deep inside. This way, I can pull it out at security without having to dig through my packing cubes.

Common Mistakes That Get Your Liquids Tossed

I’ve watched so many travelers argue with security agents. It never works. 99% of the time, it’s because they made one of these avoidable mistakes.

• The “Almost Empty” Trap: This is the big one. You have a 200ml (6.8oz) bottle of sunscreen that is almost empty. You think, “There’s only 50ml of liquid in here.” This does not matter. Security agents look at the container size, not the liquid amount. A 200ml container is a 200ml container. It will be tossed. I learned this the hard way in Berlin with a half-empty bottle of moisturizer.
• The “Oops, I Forgot” Bottle: You breeze through security, and then the scanner flags your bag. Buried at the bottom is a 16oz water bottle you forgot to empty, or a can of soda. Always do a final check for stray bottles.
• The “Is This a Liquid?” Gamble: You try to bring a jar of jam, a snow globe, or a tub of cream cheese. As we covered, if you can spread it, it’s a liquid. Don’t gamble if you’re not prepared to lose it.
• The Hidden Bag: You have your main 3-1-1 bag, but you forgot about the small tube of hand lotion in your purse or the lip gloss in your jacket pocket. All liquids must be in that single bag.

Don’t just take my word for it. The rules can be specific by country, though the 100ml rule is nearly universal. I always recommend a quick check of the official guidelines before a trip. For flights in or from the US, the TSA liquids rule page is the final authority.

Beyond the Basics: Special Considerations

There are a few important exceptions to the 3-1-1 rule that every traveler should know.

• Medications: Liquid medications (prescription and over-the-counter) are exempt from the 100ml limit. You do not have to put them in your 3-1-1 bag. However, you must declare them to the security officer at the checkpoint. I find it’s best to keep them in their original packaging with the prescription label, if possible.
• Baby Food and Milk: Formula, breast milk, and juice for infants or toddlers are also exempt. Again, you must remove them from your bag and declare them to an officer for separate screening.
• Duty-Free: If you buy a bottle of alcohol or perfume in the duty-free shop after you pass security, you can bring it on the plane. It must be in the sealed, tamper-evident bag the store provides. If you have a connecting flight, you may have to go through security again, so check the rules for your connecting airport.

FAQs: Your Quick Questions Answered

1. Can I bring a completely empty water bottle through security?

Yes, absolutely. This is a key part of my travel kit. I bring a 20oz empty, reusable water bottle and fill it up at a fountain on the other side of security.

2. Does solid stick deodorant count towards my liquid limit?

No. A solid stick or a dry powder deodorant is not a liquid and can be packed anywhere in your carry-on. A gel, roll-on, or aerosol/spray deodorant is a liquid and must follow the 3-1-1 rule.

3. What’s the exact size for the 3-1-1 bag?

It should be a one-quart (in the US) or one-liter (in Europe/Asia) bag. The sizes are very similar, and I’ve never had an issue using my 1-quart bag globally. The key is that it’s in that ballpark and has a zip-top.

4. Are makeup items like mascara and lip gloss considered liquids?

Yes. Any makeup that is a liquid, gel, or cream (like mascara, liquid eyeliner, lip gloss, liquid foundation, or cream blush) must be under 100ml and fit inside your single clear bag. Solid lipstick, powder blush, and eyeshadows are not liquids.

Conclusion: The Real Freedom of a Liquid-Free Bag

Navigating the 3-1-1 rule can feel like a chore, but it’s just another system to optimize. The real goal of minimalist travel isn’t just to follow the rules, but to create a system that makes the rules irrelevant.

By shifting your mindset from “how do I pack my liquids?” to “how do I replace my liquids?” you reclaim control. You remove the single biggest source of stress at the airport. The freedom of packing your bag, knowing it will sail through security without a second glance, is worth far more than any brand of liquid shampoo. It lets you stop thinking about the checkpoint and start thinking about the trip ahead.