Caffeine
Thanks guys, Its interesting because no one can give a definitive answer. I have received answers claiming anything from 200mg to 400mg is acceptable. However, there appears to be no authority for these answers merely, what has been written! (but who wrote it, what is their authority?) When you read the texts it refers to everything that people are thinking about ie how many Americano's can I have in one day, but the texts don't quote exact figures or quote a valid reference. What I had thought was a simple quest turns out to be a much bigger problem and yup, ive been to ICAO, IATA, CAA, NATS etc! All help most gratefully received.