PFE, BFE, and VFE Explained

PFE, BFE, and VFE Explained

When purchasing masks, we often come across 3 key specifications that help indicate how effective the mask is - PFE, BFE, and VFE.

Simply put, these numbers who how effective the product is against filtering particles, bacteria, and viruses. All legitimately produced masks are tested by independent laboratories to ensure it is actually effective, the most popular being Nelson Labs and SGS.

Most masks test against particles, viruses, and bacteria using ranges between 0.1 to 3 microns.

Particulate Filtration Efficiency (PFE)

This describes a mask's filtration efficiency when it comes to particles, including dust, pollution, and even viruses and bacteria. It's an efficiency rating for filtering particles of various sizes, and normalized to an average percentage. Of course, there are different efficiency levels for various particle sizes, as illustrated by this chart:

Bacterial Filtration Efficiency (BFE)
This tests the efficiency for filtering bacteria, which is also performed using bacterial specimens of different size. Most quality manufacturers will have masks that filter out at least 95% of bacteria.
Viral Filtration Efficiency (VFE)
Similar to BFE, this tests the penetration efficiency of viruses (such as the flu virus). For context, a good rating is >95%+, but lease note that not every virus is tested on the masks and there are viruses of varying sizes.
As a general tip, it's always better to purchase products with higher efficiency levels as it can filter out the most particles. However, there is nothing that can guarantee 100% protection, which makes social distancing and washing hands more important than ever.