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➡️ The best mask is an N95, but all masks work

➡️ Double masking or overmasking

➡️ FAQs are:

❓ Does it make a difference?

❓ Which mask should go on top, the cloth mask or the medical mask?

❓ What about two cloth masks?

❓ Or two medical masks?

➡️ Answers at updated page:




The most efficient respirator is an N100 or P100 elastomeric, not N95.

Generally, you should not wear anything over a FFP N95 because it can distort the shape of the mask and allow air to leak in around the mask.

If you are in a setting where you need to protect against splashed liquids as well as from airborne particles, then consider wearing a face shield, or wear a medical N95 that is resistant to body fluid splashes.

If you are trying to protect against current variants of the SARS-CoV-2 virus, you should wear an N100 or P100, especially if you are in an enclosed space with someone who is symptomatic, because an N95 may not filter out enough of the virus particles to prevent infection.


Also, if are worried about source control, you can wear a procedure mask or surgical mask over the exhaust valve of your elastomeric (on some models), but make sure it is loose enough so that is doesn't interfere with the seal of the mask. (If you need complete source control, then you'll need a SCBA respirator, and lots of other protocols.)


@Pat I'm not sure why anyone who understands transmission would wear a respirator with an exhaust valve?


>"I'm not sure why anyone who understands transmission would wear a respirator with an exhaust valve?"

- When you properly wear an N100/P100 elastomeric respirator whenever you are in a potentially contaminated environment, your chances of becoming infected approach zero, which means you're not a source, so source control is unnecessary. (In effect, the source control occurs during inhalation.)

- If the valve is properly maintained, it will not allow leakage under negative pressure.

- Source control in the general population is only effective when nearly everyone practices it (and then only partially effective). When half of the people are running around without any mask at all, it becomes pointless.

- An exhaust valve greatly increases comfort, especially when wearing the respirator for long periods.

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