Heat tape is not dangerous if you have even a rudimentary knowledge of electricity. I am guessing that CSA is the equivalent to UL in the states. UL listing is granted after they inspect a companies manufacturing facilities and certify all the components and orocesses for assembling the electrical end item. You would never get listed for "doing something at home". That doesn't mean it's not safe. If you add a dimmer switch to a lamp, that lamp is no longer UL certified, but it doesn't mean it's unsafe. If you use heat tape, make sure you understand the basics of electricity and follow all normal precautions. It is simple to use, cost effective and efficient.