I think they can open either in or outwards, but there are regulations on windows opening inwards more than 100mm, that are not above a height of 2 meters. They should have some kind of barrier around them. (Part n building regs?) The window is not only a means of escape but also should be an access route for firepersons with consideration that they are fully kitted out with equipment. I'm presuming that this windows have only recently been installed.
Your local building controls officer can give you a better explanation of the regs, I have found them most helpful in projects.
Hope this was of use