Supposedly the Halide torch has been discovered to put off some pretty toxic fumes. That said, my Dad used one a lot beginning in the mid fifties and he's still alive at the age of 88. He is suffering extreme Dimensia, but it's hard to say whether such things have anything to do with it.

The torch is somewhat inexpensive, but I've never really been a fan. You get your hands on a Tekmate and you won't be satisfied with any other form of sniffing leak detection.