I am a gluten free celiac who has been advised to have some food on hand just in case the airline messes up my GF meal. One of the things I had planned to take was small, 1.5 oz packets of peanut butter, until I read that sometimes peanut butter is not allowed. I ended up contacting TSA - both by phone and email - and thought the answers I received might be helpful to someone else.
Live person reply: Since the packets are 1.5 oz and I plan to put them in my quart size liquids bag, not an issue at all.
Email reply:
Thank you for your email message.
Passengers are allowed to bring special food items and liquids for necessary for medical conditions. Passengers are not limited in the amount or volume of these items they may bring in their carry-on baggage. However, if these items exceed 3 ounces or are not contained in a one-quart, zip-top plastic bag, the passenger must declare the items to one of our TSO's at the checkpoint for further inspection. Guidelines have been provided to all airports that should allow the TSO to clear these items.
Regarding your question as to how you may prevent spoilage to your special food items, any food items that you can freeze and have securely wrapped or in a spill-proof container may be carried through the security checkpoint. After you clear the security checkpoint, ice may be purchased inside the secure areas of airports for you to cool any other food items for the duration of your trip.
We encourage you to visit our website at www.tsa.gov for additional information about TSA. We continue to add new information and encourage you to check the website frequently for updated information.
TSA Contact Center
I did not ask about keeping food cool, so I assume there is some kind of keyword recognition program at work... which may explain why I received my answer in less then 24 hours. :o)