Are the Amazon-only respirator brands like AirGearPro safe to rely on?

Specialist subreddit threads we reviewed are sharply skeptical. r/Masks4All commenters have flagged that the majority of top Amazon respirator hits are 3M knockoffs without NIOSH certification, and at least one tester in those threads describes the copies as failing badly versus the genuine 3M masks. They may work for nuisance dust, but for any serious chemical, lead or silica exposure, reviewers steer buyers toward NIOSH-approved 3M, Honeywell or GVS units.