Purity tests are not a bad thing. Its ironic, because purity tests are extremely important with money. For instance, historically money has been debased by not using pure gold. Governments would start using only 95% or 90% pure gold.
If you want a mask or are required to wear one, I recommend Fake Masks USA. Not sure if they are still up. For those required to wear masks during the covid shitstorm, they produced masks that you could actually breath through. They were just mesh to make it look like you had a real mask on.