From outside you cannot open impact windows unless they are unlocked from the inside. In case of an emergency and you need to get inside from a window, it will be harder to get in due to the impact glass but it’s still possible. The fire rescue has special tools to break through impact glass quickly. If you don’t have those tools it is still possible to enter the building. By getting an ax or a large, sharp object, hit the edges on the window to make it crack. After that is when you take the sharp side and hit the edges again to make it pop out of place. Although time-consuming, this is how impact windows can be opened from the outside in case of emergency.