None of the following are true about N95 masks except

N 95 masks N 95 masks were designed by NIOSH for occupational safety of industrial workers. The masks come in different series N for Not resistant to oil. Used when oil paiculates are not present. R for Resistant to oil. Used when oil paiculates are present and the filter is disposed of after one shift. P for oil Proof. Used when oil paiculates are present and the filter is re-used for more than one shift. All 3 series come in variations of 95,99,100 which basically implies their percentage of filtration efficiency againt paicles bigger than 0.3 micron being 95%, 99% and 99.97% respectively. Facial hair can prevent the mask from forming a tight seal thus CDC has listed facial hairstyles which do not hamper the effectiveness of N95 These masks have been found to be effective against influenza viruses and are now currently being used for COVID-19