Originally Posted by
tentseller
The planes need to be ready to roll right after de-icing or else a second de-icing would be needed, especially in extremely poor weather.
You don't want to be near the fluid that is used to de-ice planes without safety clothing or snug inside an aeroplane with doors closed.
Two excellent reasons. I can add one more...............gate space is at a premium.
For those who haven't seen it, YYZ has a dedicated de-icing area where de-icing fluid gets recycled.