CDC and WHO recommend NIOSH certified N95 or European CE certified EN 143 P2/EN149 FFP2 (which is comparable to the Australian Standard AS/NZS 1719 rated P2). The P2 particulate respirator must filter out 0.3 micron particles using these test methods at a 94% efficiency in order to receive its P2 rating. Also referred to as P2 Respirators.