I had a Baku 601D hot air reflow soldering station smoke on my bench over the weekend, with all switches 'off'. It's not CSA or UL (or anything else)
It was a transformer failure. None of the front panel switches actually disconnect the line. Only protection was an 8A fast blow fuse. It had blown sometime before the plug was pulled, so I guess it did its job.
The hot air gun is directly live through a triac circuit at all times that it's plugged in.
I've rewound a new transformer, with a thermal link, higher temperature bobbin/wire. It will have its own fuse. Will also repurpose one of the front panel switches to disconnect the AC line and add a ground wire on the line cord.
. . . . of course it's still not CSA or UL.
RL