[M T]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

Oldalum, thanks for the pointer.  I had heard masks were becoming available but I hadn't chased it down.  I have two (K?)N95 with exhaust valves from the time of the smoky fires that I've been saving in case I had to go somewhere risky.  (These aren't considered adequate face coverings in San Mateo county, so I would wear a second mask on top of them.)

There's not much difference between N95 and KN95.  (In the two places I looked, neither mentioned quality control as an issue.)

See this comparison.  N95 masks have slightly less resistance to inhalation and exhalation.  KN95s are fit tested by the manufacturer on people to have a maximum about of leakage.  (I believe in the US, (some?) healthcare workers are required to be fitted for their N95 masks, but I don't know the details.)

Ace Hardware's web site lists 3 types of such masks:
1.  Available for pickup (tomorrow at my store) or ship or delivery:  World Tech's KN95 Face Mask features a BFE (Bacteria Filtration Efficiency) and PFE (Particle Filtration Efficiency) of 95%, ensuring a high level of protection.

• = 95% Filter performance
  
• 85 L/min flow rate
  
• = 8% inward leakage
  
• = 350 Pa Inhalation resistance - max pressure drop
  
• = 250 Pa Exhalation resistance - max pressure drop
  

EDIT: I believe this mask is distributed by World Tech Toys out of Valencia. They have a rating of F by the BBB. Their web page seems to have no association of medical supplies.

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95
The KN95 is a standard for respiratory equipment which filters 95% of particulates greater than 0.3 microns. KN95 masks are a PPE. They offer significant protection over standard surgical blue 3 ply masks and are approved by the CDC as acceptable replacements if N95 masks are unavailable.

• 3D perfect fit technology
  
• Moldable nosepiece
  
• Easy breathing
  
• 5 Layers of protection
  

(See www.annieinc.com, a US company that supplies both N95 and KN95 wholesale.)

3. Unavailable:  3M N95 Sanding and Fiberglass Cup Disposable Respirator White  (3M 8200HA1, no valve)

Of the two available, the Annie Inc mask has more complete information (pictures of packing where you can read the instructions, description of each of the 5 layers).
Both cost between $8.50 and $9 for a pair of masks

[M T]

I always wear a mask.  

I hope it's an N95 mask: that will protect you better than a cloth mask. They are available now to the public (e.g., Ace Hardware has had them in stock for weeks, limit 2 per customer).

Are these KN95 or N95?  I am hearing that N95s are the preferred (allowed?) version to use in hospitals but I don't know the exact reason (KN95s are from China, so quality control may be a part of it)

Oldalum, thanks for the pointer.  I had heard masks were becoming available but I hadn't chased it down.  I have two (K?)N95 with exhaust valves from the time of the smoky fires that I've been saving in case I had to go somewhere risky.  (These aren't considered adequate face coverings in San Mateo county, so I would wear a second mask on top of them.)

There's not much difference between N95 and KN95.  (In the two places I looked, neither mentioned quality control as an issue.)

See this comparison.  N95 masks have slightly less resistance to inhalation and exhalation.  KN95s are fit tested by the manufacturer on people to have a maximum about of leakage.  (I believe in the US, (some?) healthcare workers are required to be fitted for their N95 masks, but I don't know the details.)

Ace Hardware's web site lists 3 types of such masks:
1.  Available for pickup (tomorrow at my store) or ship or delivery:  World Tech's KN95 Face Mask features a BFE (Bacteria Filtration Efficiency) and PFE (Particle Filtration Efficiency) of 95%, ensuring a high level of protection.

• = 95% Filter performance
  
• 85 L/min flow rate
  
• = 8% inward leakage
  
• = 350 Pa Inhalation resistance - max pressure drop
  
• = 250 Pa Exhalation resistance - max pressure drop
  

EDIT: I believe this mask is distributed by World Tech Toys out of Valencia. They have a rating of F by the BBB. Their web page seems to have no association of medical supplies.

2. Available for pickup (in a few days at my store) or ship or delivery:   Annie Sterile K95
The KN95 is a standard for respiratory equipment which filters 95% of particulates greater than 0.3 microns. KN95 masks are a PPE. They offer significant protection over standard surgical blue 3 ply masks and are approved by the CDC as acceptable replacements if N95 masks are unavailable.

• 3D perfect fit technology
  
• Moldable nosepiece
  
• Easy breathing
  
• 5 Layers of protection
  

(See www.annieinc.com, a US company that supplies both N95 and KN95 wholesale.)

3. Unavailable:  3M N95 Sanding and Fiberglass Cup Disposable Respirator White  (3M 8200HA1, no valve)

Of the two available, the Annie Inc mask has more complete information (pictures of packing where you can read the instructions, description of each of the 5 layers).
Both cost between $8.50 and $9 for a pair of masks