Quick answer: in the US, breast milk, formula, and baby food are exempt from the standard 3.4 oz liquid limit and don't need to fit in a quart-sized bag — but you do need to declare them separately at security. Ice packs and gel packs for cooling are allowed too, even partially melted. Rules are broadly similar in the UK, EU, and Australia, though it's worth checking your specific airport and airline in advance.
What TSA Actually Allows (US Flights)
According to the TSA, formula, breast milk, toddler drinks, and baby food in quantities greater than 3.4 ounces are allowed in carry-on baggage and don't need to fit within the standard quart-sized liquids bag. These are classified as medically necessary liquids, and your baby doesn't need to be traveling with you for this exemption to apply.
How to Get Through Security Smoothly
- Declare it upfront: tell the TSA officer at the start of screening that you're carrying formula, breast milk, or baby food over 3.4 oz
- Remove it from your bag: these items get screened separately from the rest of your carry-on
- Use clear, translucent bottles where possible: not required, but it speeds up screening compared to opaque containers or pouches
- Ice packs and gel packs are allowed, regardless of whether they're partially melted or slushy
If you'd rather not have these items X-rayed or opened, you can say so — additional screening steps (like advanced imaging or alternate testing) will be used instead.
Strollers, Carriers, and Car Seats at Security
Per TSA guidance, strollers, baby carriers, and car/booster seats must be screened by X-ray. You'll generally need to remove your baby from the stroller or carrier and carry them through the walk-through metal detector — infants in a sling or carrier can typically go through together with you, though this may be subject to additional screening.
Packing Your Diaper Bag for the Flight
Beyond the liquids rule, a few travel-specific additions are worth packing:
- Extra diapers and wipes — more than your usual day-out amount, in case of delays
- A change of clothes for both baby and yourself (turbulence and blowouts have bad timing)
- A pacifier or comfort item for takeoff and landing
- If your bag has a USB port, a portable charger or your bottle warmer for in-flight feeds
A bag with a built-in changing station, like the happibag™ or happibag luxe™, is particularly useful for flights, since airplane lavatories rarely have a reliable changing surface.
International Travel Notes
The UK, EU, and Australia generally follow similar principles for breast milk and formula as medically necessary liquids, though specific procedures and exemption thresholds can vary by airport and airline. It's worth checking your departure airport's specific guidance and calling your airline in advance if you're uncertain, particularly for connecting flights through multiple security checkpoints.
Frequently Asked Questions
Do I need to declare breast milk if my baby isn't traveling with me?
No — per TSA guidance, you don't need to be traveling with your child to bring breast milk through security in the US.
Can TSA make me open or taste-test breast milk?
Screening will not involve placing anything into the liquid itself. You may be asked to allow X-ray, alternate testing like explosive trace detection, or additional screening, and you can request alternatives if you prefer not to have the liquid X-rayed.
Are baby food pouches allowed through security?
Yes, puree pouches and jarred or canned baby food are included in the same medically necessary liquid exemption as formula and breast milk.
Do I need to remove my baby from a carrier at security?
The carrier itself needs to be screened by X-ray, but infants can often go through the walk-through metal detector while being worn in a sling or carrier, subject to additional screening at the officer's discretion.
The Bottom Line
Flying with a baby comes with real exemptions that make security easier than the standard liquid rules suggest — the key is declaring formula, breast milk, and baby food upfront and packing them somewhere easy to access for separate screening. For everything else worth packing, see our complete diaper bag checklist, and browse travel-ready bags in our Travel & Diaper Bags collection.