Looks like a paint vapor mask.
Sales of these respirators are becoming more common in Beijing. I recall how badly my lungs and eyes hurt on a SoCal summer day if I as out playing baseball. Because of the amazing advances in cleaning up cars, smog alerts come very seldom now. Car makers always argued about smog control devices. Unfortunately, they had to be dragged kicking and screaming to make the changes. I don’t want government involvement when the private sector can solve problems. But without some of the regs, catalytic converters may still not be on vehicles.