As long as they are away from the room you are fogging.
And after the two hours of fogging you have to air out the room for 30 minutes or so and then vacuum. After you have done this, then the cats can go back in the room.
And after the two hours of fogging you have to air out the room for 30 minutes or so and then vacuum. After you have done this, then the cats can go back in the room.