Top positive review
Canadian made quality masks -ASTM F2100
Reviewed in Canada on February 19, 2021
Disposable masks look similar if not identical, but the degree of filtration (protection) and how much they impede breathing (comfort) can vary greatly. These masks meet a recognized North American standard, ASTM F2100 so you know how much protection they offer and how much they impede breathing. They are offered at the 3 levels that the standard specifies. These are medical procedure masks (Level 1), and surgical masks (Level 3) that are mentioned by health authorities.
The ASTM standard requires that the package (in this case, the box) has ASTM F2100 printed on it along with the Level 1, 2, or 3 (or L1, L2, L3). Packages lacking that marking are non-medical masks and you don't really know how much protection they offer. You can't tell by looking, but only through testing, and quality manufacturing processes to ensure that each masks will perform the same. These masks filter out at least 95% of particles 0.1 microns in diameter if the mask is fitted to seal well against the face.
The main difference between the 3 levels is fluid resistance, how difficult it is for fluid to get through the mask. Level 2 provides more fluid resistance than Level 1, and Level 3 provides the most fluid resistance. Level 1 filters out 95% of particles that are 0.1 microns in diameter while Levels 2 and 3 filter out 98%, resulting in slightly more resistance to breathing.
I recommend these masks. The ASTM F2100 standard provides assurance that the masks provide the same level of protection as masks used in hospitals. There are other standards, notably the European standard EN 14683, but in North American the applicable standard is ASTM F2100, provided by the American Society for Testing Materials. Also note that N95 is a different standard provided by NIOSH (National Institute for Occupational Safety and Health); these are NOT N95 masks.