POR 15 does indeed contain isocyanates. A simple organic filter mask is not sufficient protection, you must use an air supplied respirator. Here's a link to the POR 15
Material Safety Data Sheet (MSDS) Me, I painted my frame with XO Rust Red Metal Primer and XO Rust Satin Black from True Value hardware
Hell, its just an old pickup truck and the original frame lasted 50 years with less protection than that.
