As a DME provider, we recommend 4 feet.
Thats 4 feet from a gas stove, firplace, candles, incense, cigarettes...etc.

Hello. I am a homecare RCP. Our recommended cleaning is... daily - wipe down mask with a wet warm cloth weekly - wash humidifier cup, tubing, mask in warm soapy water (whatever soap u use in the sink, original version) monthly - after washing in soap/water, use 1 part white vinegar & 4 parts water t...