I’m getting 20+ emails a day from suppliers who are now selling masks. I honestly can’t tell you from which I saved that.
The key is that it simply doesn’t matter. Unless you are wearing a hospital grade N95 mask, that disclaimer applies.
It is also important to know that nearly no one even uses these (useless) masks properly anyway. Once you have the (already useless) mask on, if you touch it with your hands it is contaminated. If you take it off and put it on again you have contaminated it.
And we are being told that we can throw on a homemade mask fabricated from fabric and realize protection from it. If you make your own mask, it is already (medically speaking) contaminated when you slap it on your face.
As far as your bishop is concerned, if he is a true believer, none of these facts will sway him.
Googling the phrase turns up a number of suppliers. Actually I used duckduckgo - https://duckduckgo.com/?q=Not+intended+for+medical+use%2C+not+recognized+by+the+CDC+or+FDA+as+safe+or+effective+against+covid-19+or+any+virus%2C+no+guarantee+item+will+protect+user+from+any+illness&ia=web