I would also add that the mask should be fit-tested and the straps should be inspected. If the straps start to wear out, you will lose your seal, which usually happens after 2-3 days of use, but could be sooner if you’re donning/doffing it (ie pulling on the straps) more frequently. Also any visible soiling or staining on the mask can compromise the filter. That’s why many healthcare workers are currently wearing a loose surgical mask over their disposable n95 during this COVID-19 pandemic. It helps keep splashes of blood, urine, feces, etc from landing on the mask and compromising the filtration.
Well-researched article, and a great case that — at least according to one company’s directors — the global economy isn’t ready to reopen. PS: I thought I’d point out that you used the Murphy USA square footage revenue in your calculation, instead of the Apple Store revenue, so the actual numbers of their losses are nearly twice as high as what you calculated.