Halon Gas is, wikipedia says, commonly used as second or third level fire suppressing agent in important facilities. As it can be harmful to human beings, it is advised as once the alarm sounds and the light starts to flash, everyone in that room need to vacate the room immediately and seal the door tight shut. Scary !
My lunch was Hor Fun. I wanted to have Mei Fun but my mouth just pronounced "Hor Fun". Anyway, it is a good dish.