Yes it is safe.
Casement window is one of the popular choices across the world. These windows are several advantages over other types of windows which have made them so popular and safe. A casement window mounted sideways with the help of side hinges that are attached to the side frames. They can be open or closed sidewise with the help of internal crank. When the crank is operated clockwise , the window is opended and when it opened in anticlockwise , it is closed. When open they provide a full view which is not possible with other types of windows. These windows are more safe and strong than other types of window.