Due to individual use, I cannot/do not accept any responsibility for the health of any user. Please remember the following tips to keep yourself and others safe:

• Your mask has a strip of metal in the top to form around your nose to help it fit and form a better barrier to outside air.

• Always keep your mask in place over your nose and mouth. You can speak without removing your mask.

• Avoid touching the outside of your mask—consider it contaminated.

• When removing your mask, do so by touching only the ribbons or elastic ear loops.

• Wash/sanitize your hands after removing your mask.

• Wash your mask frequently. Masks may be washed with regular laundry. I prefer to place them in a lingerie bag to keep the ribbons from tangling with other laundry or to keep the elastic adjusters from being lost. All fabric is prewashed and dried on high.

• Remember to remove the filter prior to washing your mask. Consider the filter contaminated once you have worn your mask. Wash your hands after handling it.

The CDC says: Two important ways to make sure your mask works the best it can

1. Make sure your mask fits snugly against your face. Gaps can let air with respiratory droplets leak in and out around the edges of the mask. Put the mask over your nose and mouth and secure it under your chin.

2. Pick a mask with layers to keep your respiratory droplets in and others’ out. A mask with layers will stop more respiratory droplets getting inside your mask or escaping from your mask if you are sick.

Face Masks Against COVID-19: An Evidence Review
https://www.preprints.org/manuscript/202004.0203/v1

"When considering the relevance of these studies of ingress, it’s important to note that they are likely to substantially underestimate effectiveness of masks for source control. When someone is breathing, speaking, or coughing, only a tiny amount of what is coming out of their mouths is already in aerosol form. Nearly all of what is being emitted is droplets. Many of these droplets will then evaporate and turn into aerosolized particles that are 3 to 5-fold smaller. The point of wearing a mask as source control is largely to stop this process from occurring, since big droplets dehydrate to smaller aerosol particles that can float for longer in air (26).

Anfinrud et al (6) used laser light-scattering to sensitively detect droplet emission while speaking. Their analysis showed that virtually no droplets were "expelled" with a homemade mask consisting of a washcloth attached with two rubber bands around the head, while significant levels were expelled without a mask. The authors stated that "wearing any kind of cloth mouth cover in public by every person, as well as strict adherence to distancing and handwashing, could significantly decrease the transmission rate and thereby contain the pandemic until a vaccine becomes available."

An important focus of analysis for public mask wearing is droplet source control. This refers to the effectiveness of blocking droplets from an infectious person, particularly during speech, when droplets are expelled at a lower pressure and are not small enough to squeeze through the weave of a cotton mask. Many recommended cloth mask designs also include a layer of paper towel or coffee filter, which could increase filter effectiveness for PPE, but does not appear to be necessary for blocking droplet emission (6, 27, 28).

In summary, there is laboratory-based evidence that household masks have some filtration capacity in the relevant droplet size range, as well some efficacy in blocking droplets and particles from the wearer (26). That is, these masks help people keep their droplets to themselves."

Choose your own filter or none at all. Research shows that 2-3 layers of cotton fabric are as effective as a disposable "surgical mask".

AIR FILTRATION FILTERS (PM 2.5)

Air Filtration filters are intended for air pollution and dust, and are used as replaceable filters in respirators and masks. The question is — are they effective against small particles that can carry viruses? Researchers from the University of Edinburgh tested different common masks and used a particle counter to see how many particles made it through a mask with a PM 2.5 air filter. They found that dust respirators with filters rated for PM 2.5 were about 97%-98% effective.

Availability: Can be purchased on Amazon.
Filter Breathability: Good.

COFFEE FILTERS

The CDC’s bandana face covering material list calls for a coffee filter as the second layer (the first layer being the bandana). The CDC does not indicate that the coffee filters are included for particle filtration, however.
Availability: Grocery stores and online.
Filter Breathability: Poor. Coffee filters are very difficult to breath through.

BLUE SHOP TOWELS

According to Business Insider, a blue shop towel made from polyester hydro knit was found to be more effective as a DIY face mask filter than other household materials. They claim that two blue shop towels inserted into an ordinary cotton mask brought filtration up to 93% of particles as small as 0.3 microns. The two brands they tested were ToolBox’s Shop Towel and ZEP’s industrial blue towel. Note that Scott’s pro shop towels didn’t work as well. Unfortunately, I cannot find any actual data on this research other than the quotes in Business Insider.
Availability: Home improvement & automotive stores and online.
Filter Breathability: Good.

*Information taken from research done by JenniferMaker, as of 3/6/21. Additional products and information can be seen on her site here.