Hey! You might want to take a little time to learn about the different certification levels for medical and non-medical grade disposable masks. It's super complicated, but i've had to learn a fair amount for my current job due to covid. Health Canada is an excellent resource -
https://www.canada.ca/en/health-can...tive-equipment/medical-masks-respirators.html
A quick rundown - there are various standards that med grade masks can be tested to. In north america, we most commonly use the ASTM rating for procedure/surgical masks. They run levels 1-3, with 3 being the highest. ASTM level 3 procedure masks are recommended for use in many medical situations, but are NOT intended to keep you safe from aerosols, and are therefore not used during aerosol generating procedures like certain surgeries, etc. In europe they use the EN rating system. Their procedure masks are rated to I, II, or IIR, with IIR being roughly equivalent to an ASTM level 2. Like the ASTM 1-3 procedure masks, these masks are not intended for aerosol generating procedures.
If you are looking to purchase a box of 50 disposable masks, purchasing a box that is clearly labelled as ASTM level x, y, z or EN rating x, y, z will generally be better quality than a brand that does not include a rating. Some of the rules included in the certification of these masks include labelling requirements on the box. If they are being sold as ASTM level 2, it needs to say that on the box.
If there is no clear rating on the box it doesn't necessarily mean the masks aren't as good, but it does mean that they are
untested. This most likely means the company does not intend for their products to be used in a medical setting, and is therefore not held to the same standard that companies who do. I personally like the comfort of knowing my masks are tested and verified. Pri-Med is a really high quality brand if you can find their products. They have been around for ages, and are Canadian owned and made.
As for KN95 and N95 masks, you will find both medical and non-medical masks. The non-medical masks are intended to protect you from dust and particulates in a construction, etc setting. These would be fine, but aren't really designed to protect you from covid or other viruses. You would be better off using a high quality procedure/surgical masks. Another thing to consider is that in order for N95 masks to be used properly, you need to be fit tested to know which style fits your face size/shape. This is something that usually happens in a work setting. If you don't know your style, you could just be wasting a medical grade masks, keeping a healthcare or first responder from being able to use it, and it still not protecting you because it doesn't fit properly. KN95 masks are a chinese certification level, and are not recommended for use in Canada because there is an extremely high number of knock-off's, as well as the lack of certification documentation to verify the quality of the masks. Within my work, we are essentially considering all KN95 masks to be of unknown quality, and no better than any other non-certified disposable masks.
I hope this is helpful. I'm happy to provide more depth/breadth about masks for those curious!