I uesd to run the tar kettle on a flat roofing crew. Sometimes we used pitch, a coal tar derivative. That stuff burns the eyes and the lungs as the fumes are acidic. We once repaired the roof at a dead animal rendering plant. Another time we did a potato chip factory. I chuckle when some "fine ladies" whine about the smell of a cigarette or black powder smoke. Those things actually smell pretty good compared to some of the places I've been. Yep I'd sooner clean a dirty muzzelloader than hang around a hair salon. That stuff reeks.