Unless these chemicals are extremely likely to cause cancer, it is probably the least cancerous thing on our gear. It’s usually covered in soot and all kinds of nasty shit. We make a huge effort to keep them out of the cab of the truck, wash them everytime they get used, and we don’t just hang out in them because of the carcinogens that get on them from use. Also, a firefighter smoking is not as common as it used to be. Far less than most other fields. Our job requires us to be in great cardiovascular condition and the few smokers get chastised for it. The culture has drifted away from being a smoke eater, we take tons of preventative measures to keep the cancer out of our bodies, but we know it’s still likely going to happen.