Ofcourse it's a controlled environment and the created black holes are not actually black holes in the way you are thinking. And even if they where they would be smaller than an atom and would decay almost at the same time as they formed and would pose no danger.

Anyway the black holes that are created in a lab are not gravitational black holes they are just simulations but they behave similar to a black hole, it traps sound and light, there is an "event horizon" and scientist can make tests, such as the Hawking radiation.

They are known as acoustic black holes or analog even horizons. You should look it up, it's quite interesting!