We like to let all parents know that TSA is very likely to do special inspections on the coolers - specifically the cooling units inside - since they don't see them every day and might be curious. The cooling units use evaporation technology and don't contain any hazardous materials like dry ice - which is usually their main concern.
Be prepared and allow extra time for TSA inspection. Just know that you are not required to put your breast milk through the X-ray machine, but you and your luggage will be subject to additional screening.
BEFORE YOU TRAVEL:
Parents can contact TSA Cares to inform TSA that they will be traveling with breast milk and a Milk Stork cooler. A specially trained representative provides information about screening that is relevant to the travelers’ specific disability or medical condition (i.e. transporting breast milk).
Parents can also download and print a TSA notification card to inform the screening agent that they are traveling with breast milk.
AT THE AIRPORT:
Should a TSA Agent inform a parent that the cooler and/or breast milk is not permitted through screening, it is recommended to request a Supervisory TSA Officer and/or Passenger Support Specialist for assistance with getting through security. Milk Stork coolers can and should be allowed through TSA.
Provide feedback for TSA, positive or negative, via the TSA contact form.
A couple of valuable resources are:
Milk Stork's Airport Security Guide