Hi Tina,
I would save a safe touch hug is one that does not involve any form of touching that the recipient is uncomfortable with, and is initiated and ended by you. Often in childhood sexual abuse we had no control over how often or where we were touched, so to have control over when and where we are touched provides us with safety.

I wanted to comment on hugs in general. My T does not hug and when I asked him if I could have one, we spent a whole session discussing why his answer was no (I didn't ask until I was ready to hear a no, since I was pretty sure that was the answer I would get. But it was important for me to do the asking, and even hearing the no was important. It was a very reparative experience for me to express a need, have it not met and know I could not only survive that but the relationship was still intact. And knowing that my T will say no, allows me to trust his "yes.") But his basic take was that providing a hug carried a fairly high possibility of doing harm without a lot of benefit. And that in my case, withholding the hug helped me to go past it to the pain and loss of not having had the safe physical embraces I craved as a child. I really think his saying no to the hug led to one of our most important and pivotal sessions.

I recently read a article on a Ps blog that explained the whole principal of why a therapist would withhold touch, and I've posted the link below.

I do want to make clear that I don't think there's anything wrong with therapist's who decide to hug. My first T was willing to hug me any time I asked and my present T does shake my hand at the end of every session. I just wanted to also offer a perspective from the other side so to speak.

A Matter of Touch by Jung at Heart

AG