In general, quite to very safe. If you mean safety against other human beings' actions, then all the Canary Islands are safe compared to other parts of the world. As safe as most civilized places. The only safer place I can think of right now might be Japan.
What is the safest part of Tenerife?
Tenerife SouthPlaya de las Américas leads to the town of Arona. Here, there is a white sandy beach, which is one of the safest on the island and is, therefore, ideal for children. In addition, there is, of course, a wide selection of dining options.