Frozen Breastmilk: How to Fly Cross Country and Keep Your Breastmilk Frozen

Frozen Breastmilk: How to Fly Cross Country and Keep Your Breastmilk Frozen

When we made our most recent move, I had to transport 400 ounces of pumped breastmilk.  After many hours of research, I determined the most efficient way to transport milk via plane.  It wasn’t using dry ice.  It wasn’t shipping it via a next day service provider.

While researching, I kept reading about using dry ice.  Did you know that for dry ice to effectively in keep items frozen,  you have to pack one pound of dry ice for every pound of frozen breastmilk?  Well, 400 ounces is equal to 25 pounds.  So I would need 25 pounds of dry ice.  Meaning, my bag would probably be over 50 pounds.  I would be paying an extra fee for “heavy luggage,” or I would be lugging around a 50+ pound carry-on bag.  Dry ice is expensive too, typically $3 per pound.

While I was researching dry ice options, I called a local butcher where I could purchase dry ice.  He was the go-to guy for buying dry ice in our city, but he did NOT recommend using the dry ice.  He said that the dry ice often changes the flavor of food, including breastmilk.  Many mothers had reported back to him that their baby would not take the frozen breastmilk after using dry ice to keep frozen.

So using dry ice was out.  The next option was to use a courier delivery service, similar to FedEx or UPS.  I would have to purchase specific boxes with dry ice compartments.  But, I already learned: Dry ice = bad!  I would have to pay for overnight shipping.  The largest box available cost $150 and would hold 200 ounces.  I also had to pay for overnight shipping, which cost $200.  Therefore, transporting 400 ounces would have cost me $700.  It would have been cheaper to buy my breastmilk a seat on the plane we took to move.

The thought of dropping off breastmilk and hoping it arrived at the next location was daunting.  I would also have to plan to ship the milk the day before we left for a house hunting trip so we would be there when it arrived.  We already had a long to-do list when we landed in our new city, and the thought of trying to remember to pick up a couples boxes of breastmilk was stressful.

So, after researching, I had to choose between icky tasting breastmilk or a high priced shipment which still used dry ice.  Neither option was good enough for me.  So, I came up with an even better option.  I knew we would be going to our new city one more time for a home-searching trip before our final move.  My in-laws also live near our new town.  So, I was going to find a way to take milk with me, safely, with each trip.

My husband and I went to a sporting goods store and bought the best cooler they had, as well as their ice blocks.  I was able to pack 200 ounces in the cooler, along with the ice packs.  Becuase I couldn’t fit 400 ounces in the cooler, I had to transport the breastmilk on two separate trips.  On our first trip, I packed the cooler the night before we left for the airport and stored it in our freezer.  It was 12 hours from the time I headed to the airport to the time we got to my in-laws’ home where I could pack the breastmilk in their deep freezer.  When we arrived at their house, the breastmilk was still frozen solid.  The second trip was our final moving trip, and I could transfer the milk into our freezer right away.

Below are a couple of tricks you can use to ensure that your breastmilk stays frozen and travels safely on your plane ride.

Tips for Transporting Breast Milk on a Flight

  1. Purchase a cooler that has a leakproof zipper and closed cell rubber foam lining to ensure milk will stay cold.   I used a YETI and it kept milk frozen for days!  You can find the YETI on Amazon, here!
  2. Pack cooler with at one reusable ice block on the bottom and one on the top.
  3. Pack the cooler the night before your flight and put it in the cooler to stay cold.
  4. Don’t open up the cooler but one time when required to at security checkpoint at the airport.
  5. Security will inspect your breastmilk at the airport.  They will open the cooler and take out each bag of milk.  You can minimize the handling of individual packets by packing them in quart size plastic bags.  If milk is frozen solid, they will only look at the bags.  If breastmilk is in liquid form, they will test each bag.
  6. Watch the security folks like a hawk and ask them to put on clean gloves.  I want them to know I am watching every move and that puts the pressure on them to work quickly to get milk back in the cooler asap.
  7. Once you arrive at your destination, put your breastmilk in the freezer right away.  If you cannot, transfer breastmilk to a deep freezer right away, place the cooler of breastmilk in a large cooler with ice to continue to keep it cold.

Breastmilk storage

15 thoughts on “Frozen Breastmilk: How to Fly Cross Country and Keep Your Breastmilk Frozen”

  • The cooler you linked is the 12…there is an 18 one on there which I assume is bigger- would that one work for a carry on as well do you know??

    • Hi Ashley, you know I am not quite sure. I know the 12 can one easily fit under the seat of the plane or up in the overhead bin. The 12 can cooler dimensions are: OUTSIDE 10” × 11 1/2” × 12 5/8”.

      And according to the FAA, The maximum size carry-on bag for most airlines is 45 linear inches.

      The 18 can cooler dimensions are: OUTSIDE 10 3/4” × 13” × 16 1/4” – which is still less than the 45 linear inches limit. But I am sure it will depend on the airline. Not seeing the 18 can cooler in person, I am not sure if it would fit in the overhead bin. But, I was able to easily fit over 100 oz in the 12 can cooler… just for reference.

  • Thanks for writing this! I have about 100 bags to move over 20 hours of traveling. Do you think I need two coolers?

  • This is seriously a life saver ! Thank you! I’ll have about 250 ounces to take. Do you think the dimensions mentioned for this cooler will hold that extra 50 ounces? I am not sure we can get the yeti but I’m hoping to find a similar cooler! Thank you!

    • Jessica, I was able to put about 200 ounces in the cooler I had, I could have probably gone bigger and still been able to carry it on the plane. Let me know if I can be of more help. Please feel free to email me at

  • did you check your cooler or did you bring it on as a carry on? I assume you did a carry on…since they checked your milk. why didnt you check the bag?

    • I brought my cooler on as a carry-on. I didn’t check the bag because I wanted to have my eyes on the milk at all times…my Type A personality, lol!

  • I have 50 bags (medela) each with 6 oz of milk. So a total of 300 oz. I am traveling direct from US to Italy, about 9 hours at the end o f the month (so cold weather). I think it makes more sense to CHECK my milk in, as opposed to try to bring it on board. What do you recommend?
    My packing = put 6 bags in a freezer zip log bag, wrap each with newspaper, then inside a cooler lined on all sides with frozen gel packs or gel blocks. Then place the soft sided cooler inside of a hard shell suit case and check it in (use clothes/etc around it so it doesn’t bounce around).


    • Hi Yasmin, yay for having so much milk to transport. You could check or carry on. Pro about checking it is that you can transport it pretty easily. Con is you don’t have your eyes on it at all times. I’m not sure if TSA would open it and check it and i would be worried they may not repack it or seal it properly. Pro about carrying on is you have your eyes on it at all times. Con would be that finding a way to transport 300 oz in a carry on might be challenging but you should be able to fit it in a rolling bag.

      I think if you were to pack it like you said you should be fine. I would get frozen gel blocks… good ones that stay frozen. I’m personally a big fan of these yeti ones: they can be pricy but they stay cold forever.

      If you do check the milk/cooker make sure the packaging can easily be closed or sealed. For example, my yeti cooler doesn’t close all the way unless you do a little extra pull at the end. If someone else were to try closing it, they probably would leave the small gap at the end and not close it all the way. But if you have a cooler/bag that is super easy to close you should be good checking it. I think they way you would pack the soft sided cooler in a hard suitcase should be ok. Let me know if you have any other questions. Good luck! And how awesome to be going to Italy. We went. Last year and it was amazing!!!

    • Ok, me again…lol.

      I’ve been thinking about it and I think you will be better off carrying the milk on with you. Because it’s breast milk you are exempt from the 3 oz rule. And you have it in your possession at all times. It’s also in a controlled environment temperature-wise. If you check it, you aren’t sure what temperature it will be stored at. I thin in you do the exact same packaging you were planning, just put it in a carry on suitcase. One with wheels will be easiest.

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