Had a guy blow up when I indicated I would prefer Teflon tape for sealing pipe threads over his favorite Master's metallic pipe dope. Here's the MSDS:

https://www.era-env.com/ERAWcfService/getmsdscontent.svc/?ke...

It's basically powdered lead in an alcohol carrier that you wipe on your threads with a brush.

At first I thought he was just a grumpy old plumber tired of liberal environmentalist kids with their newfangled safety regulations, but perhaps the lifetime of working with leaded solders and leaded thread sealant has affected him in some way...