Safeties either work or they fail. It's not really the kind of thing that needs to be or should be qualified with modifiers.
Is it working? If you can't answer with an unqualified "Yes." then it's not working.
Is it dangerous? Assuming the gun needs a grip safety then it's dangerous for it not to have one. But it's MORE dangerous, in my opinion, for it to have a grip safety installed that doesn't work properly.