Best Respirator for sawdust

I don't know anything about your age/health/respiratory history so I will just offer this as a simple suggestion… If you are planning to work with a "respirator" on, you might consider your age/health/respiratory history. If there is anything there to be concerned about with the use of a respirator, you might want to have your physician check your physical condition with the idea in mind that you will be wearing one while working. Fit testing, training and a medical evaluation would be required before using a "respirator" if you were working at a job covered under the General Industry Standard so, if at work you would go through those hoops, why not do it if you were going to wear one at home. Sorry, don't mean to lecture but I had to mention that as it is something I used to preach during my days working in occupational health and safety.
Mike

The mask model is about fit and comfort. The filter cartridges are probably the most important thing to pay attention to. There are different cartridges for different applications: particulate filters for sawdust, organic vapor cartridges for finishing, etc. If you use the wrong cartridge, it won't protect you.

They make combination cartridges that protect against multiple hazards. Be aware, however, that the useful life of a cartridge varies considerably depending on its type. An organic vapor cartridge is good for something like 8-10 hours of use (not sure what the exact time is), but a particulate filter might be good for months (if you are a hobbyist like me). The combination cartridges will have different useful lifespans for different types of hazards-so don't think you can use a combo cartridge for finishing after you have used it for 30 hours to protect against sawdust.