Naw, he's got a tub of water to find the leak, and a clamping and vulcanizing set up, a bottle with (I'm guessing) soapy water to reseat the tire carcass, and a basket of odds and ends. I don't think the EPA or OSHA would have any issue with those chemicals. He's even atba safe distance with his open toed shoes. My mechanic instructor would always tell us,
"Any port in a storm"
As a reminder that sometimes the repair just has to work to be "correct".
He was old school, also fond of saying
"Every good mechanic is standing on a pile of broken parts."
You don't get to be skilled without experience.