3M published this Quick Reference Guide to Respiratory Protection from Wildfire Smoke Inhalation in July of 2019 to help address the recently passed Cal/OSHA rule. (3M is a major manufacturer of safety equpment, including respirators.)

Per 3M, if you choose to use a reusable respirator with a combination organic vapor and P100 cartridge, (which we think sounds like a very good idea), you could consider a 6000-series respirator (6100/small, 6200/med, 6300/large) and the #60921 cartridge. We've also seen some other respirators that seem to provide similar capabilities.)