The TSA Liquid Regulations limit you to 3.4 ounces of bottles or containers.
This is because 3.4 ounces is equivalent to 100 ml, which is consistent with TSA in other parts of the world using milliliters and the metric system.
But what if your bottle is 4 ounces? That’s only 0.6 ounces more, but does TSA allow 4 ounces of bottles over security?
What if the bottle isn’t full and contains less than 3 ounces of liquid? Is it a 4 ounce container travel size?
Let’s check.
Can you take 4 ounces by plane?
Simply put, it’s not!
The TSA is very strict about this. If the bottle or bottle label says 4 ounces, do not pass it.
If a small, almost travel-sized bottle is in a quart-sized plastic toiletry bag, TSA often doesn’t realize it’s a little too big.
But when they notice, you check your bag or hand over the product, that is, throw it in the trash.
You can’t even ingest 3.5 ounces of liquid by plane. The rule is the rule.
But are there any exceptions that allow 4 ounce bottles on an airplane?
Take a look at @AskTSA on Twitter.
Jeff was able to bring in 4 ounces of bottled water that he used to make powdered milk:
Lori was able to bring 4 ounces of cough medicine:
The 3.4 ounce fluid ounce rule does not apply to taking medicines by plane, whether prescription or over-the-counter.
Malinda tries to consume 4 ounces of yogurt during the flight, but TSA says it is not allowed:
Tabisa has discovered that she can take 4 ounces of contact lens solution.
The Verdict
Most types of liquids do not pass through a 4 ounce bottle. Security guards do not allow 4 ounce bottles through security.
Exceptions apply to pharmaceuticals or medically required liquids.
You can also bring breast milk, baby food and baby juice.
If you purchased the liquid after security, you can bring a larger bottle.
If the liquid container is too large, just transfer a portion of it to a small bottle. For this reason, travel-sized silicone bottles are great.
Travel-sized products are very expensive in drugstores, which can save you money in the long run.