My mother-in-law taps his hands when he does something she does not approve of, but I told my husband to tell her to stop it because our son has learned to spank because of it. He follows everything we do and I really would not want for him to get the idea that hands are for spanking or hurting.
Regarding the safety, we all watch him very closely and we have kept everything sharp out of reach, although it does not guarantee us of his safety, it makes the environment safer for him to explore.