Those are actually nice for jumping, because in case you fall off while jumping, and your horse takes off, then at least you won't be dragged off to the other side of the field. So yes, they are safe for jumping.
For me though, the rubber thingies on my safety stirrups are wearing away, and now they come off to easily, especially with jumping. So when I have the money I'm going to replace my safety stirrups with normal stirrups.
But that is completely up to you.