No, it will not be safe to use them. They are not designed for 230V. As an aside they are also not fire rated so should not be fitted if any living quarters above unless you put a fire hood on them. New ones are not expensive and would be the safe and correct option.
In addition you would need to get an electrician to test the existing earth and also for him/her to check if the existing circuit is RCD protected and if so to test the RCD is within parameters (amongst other required tests).