grrr just typed this and then baby pressed keyboard
bf has just sounded out union rep whilst on a chip pan fire call.
you have 2 options
1) not to tell anyone and continue as normal. BUT if you have an attack whilst on call / in BA then you and crew will be in big trouble.
2) to make it known. you cant be sacked. They can send you for a medical which would decide if you can continue (if unlikely to have an asthma attack) or to be put in a non BA roll, driver etc.
Number 1 is not advisable at all