Priming the fender

[yossarian19]

I used to work in a shop in Berkeley. The bossman had relationships with local body shops, as any mechanical shop ought to. Many of the local body shop owners have had employees quite literally drop dead while on the clock. Personal Protective Equipment (PPE) is like death & taxes, man. Stuff is mandatory.
If POR15 states you need a respirator to spray it, listen.
If they say you can brush it on, though, believe it.
Personally I'm starting to do enough painting to invest in a higher quality respirator and a wet mop for the garage. You don't really even want to sweep the paint / rust dust that comes off a 70s paint job.