The JAA rules go something like this;
Aircraft with more than 44 seats must be able to be evacuated within 90 seconds with half of the exits unavailable.
If the door sill is more than 6ft from the ground (with aircraft in normal attitude) then an emergency slide is required.
If required, a slide must inflate in 10 seconds into a 25kt wind.
I would assume the FAA rules are very similar, if not identical.