With any 2 component paint and particularly catalyzed urethanes, the best idea is to figure out how to get "supplied air" - that is, air coming into your mask from an outside source.
I'm trying to find a low cost supplied air method and recently had someone say to me, "Do you know anybody that scuba dives...?" I think his idea was to find an out of date scuba tank and fill it just enough to get about 10 - 15 minutes breathing time out of it. Haven't followed up on it but maybe one of these days?
It's not BS, we're all not a bunch of fear mongers, please please please take the appropriate precautions when you use this stuff.
I worked with Boeing Aircraft among others for years on health and safety issues and all I gotta say is, "be careful out there" - which is what they said on Hill Street Blues back in the '70's and what you should do in your shop.
It would be a shame to build a really boss bike and be too sick to ride it.
Pat.