If you're traveling on business, Can you check in breast milk from Thailand flight to Manila?

I believe it depends on the airline you're taking. If you're flying through Philippine Airlines, they will allow you to have breastmilk in tow. However, you must be travelling with an infant/kid in order to be allowed, as specified. You may check if they allow such liquids even without an infant/kid. I've read last night at Breastfeeding Pinays that one mama was only allowed with only a total of 1liter, and it should be hand carried. She took a Cebu Pacific flight. For clarifications, it's better to contact the airline so you'll be aware of their protocol.