That’s a bullshit test. I used to do lab work, if you even open a prepared sterile dish in an uncontrolled nonfiltered area, masks or no, it’s contamintaed. Every time. You need proper filters, uv sterilizer, air flow curtains... I don’t wear a mask, unless it’s rated for what I’m doing. Dust, asbestos, mold, voc’s, etc. nothing you can buy is rated for viruses. Full bubble suit, remote pressurized air. Fucking random old leggings, T-shirt’s... good lord people. This is propaganda in the guise of medical information.