A Filter By Any Other Name


Masks and COVID19 prevention. It is a topic of great debate. Many believe this simple personal protective equipment device to be the key salvation that will knock down the virus if only every single person would wear a mask in public. Do this and many believe that the virus would be beaten. There is another group that believe wearing a mask will not stop the spread of the virus and possibly cause more underlying issues due to dirty masks, difficulty exhaling CO2 emissions and generally increase in breathing resistance.

The truth is most likely somewhere between the two beliefs.

In past ramblings and in chapter one of Disturbance In The Force I’ve written about immune system strengthening through a daily regimen of the correct vitamins and supplements, getting plenty of sleep and eating healthy foods that do not promote inflammation. It is unfortunate that healthcare officials do not stress this important wellness issue at all.

Of course, there is social distancing, frequent 20 second or more hand washing and not touching your face.

The recent onset of mRNA vaccines has many hoping for herd immunity developing. We will see, time will tell on vaccination.

However, the big debate is still on masking. Masks are a form of filtration. It makes sense to worry about filtration as it pertains to this virus. COVID19 is most likely to find it’s hosts via particles that are airborne. One way to stop the virus particles from finding a new host is to trap them in a filter.

Masks and filtration are a subject that Ramblin’ Ron spent the better part of 30 years working with. Specifically, the Personal Protective Equipment (PPE) Devices known as respiratory protection. In October of 1983 the 3M Corporation hired me to work in their Valley, Nebraska factory’s Quality Lab to perform NIOSH acceptance testing on the respiratory protection devices that they manufactured. NIOSH is the government agency that OSHA relies upon to develop approval standards for such protective devices.

After testing these devices for 10 years I spent 3 years in the lower management positions of Production Control and Production Supervision before leaving the facility to spend the next 7 years advising customers and potential customers of the best solutions to their airborne contaminate issues and training their employees if respirators were the solution chosen.

In 2005, Honeywell recruited me to work in their sales and marketing group specifically to bolster, at the time, a fledgling respiratory protection group within the safety division. Spending 10 more years advising and training people how to reduce or eliminate airborne exposures.

At this point you may be asking: So what? That’s a fair question. The ‘what’ is the filter. There are many types of PPE filters, and there are more types of filters now than when I was in the business of PPE and respirators through 2015.

The red novelty mask pictured above is the most common mask being used to protect ourselves and others from virus particles. At best they are 70% efficient. When two people in the same proximity are both wearing masks of this type combined filtration is around 90% according to most tests. Good, but not great. Combined with immune strengthening, distancing, good diet, sleep and good hygiene practices, even better.

Photo by CDC on Pexels.com

The mask pictured above is a Filtering Face Piece Respirator (FFR), the general public calls them paper masks, dust masks and more recently and more accurately N95s. This pictured mask has a valve. In industry, this type is preferred for maximum comfort and minimum CO2 build up while wearing it for extended periods of time. But not recommended for a person that suspects that they are infectious.

Photo by CDC on Pexels.com

The photo above shows two FFRs without a valve and one with a valve. The two without a valve are N95 FFR. The greenish blue one is specifically designed for the healthcare industry and the white one is for general industry. Both FFRs are three-layer masks that are designed and tested to filter out a minimum of 95% of particles at a .3 micron particle size. For a point of reference, most airborne pathogens like SARS COV2 (COVID19) are between 1 and 2 microns in size. A functioning N95 is closer to 99% efficient for the COVID19 virus particle. That is very good.

So, what is the difference between the medical device and the general industry device? The outside layer of the medical N95 is coated with a fluid resistant barrier that will knock down liquid particles before they get to the actual N95 filter in the second layer. The industrial N95 will absorb fluids which breaks down the filtering properties quicker if exposed to heavy fluid particles. The third layer on the users face is for structure.

While the N95 FFR is the most common and, at the moment, the most rare of PPE to purchase it is much more protective than the first mask pictured on this post. NOT just from a filtration issue, but also from a fit issue. If it leaks, it is less protective. FFR manufacturers spend much time and money assuring that their products have the ability to fit a large segment of society.

The newest addition to the mask market pictured above is the KN95. Legitimate KN95 masks have the same filtration and testing as the N95, but they attach to the user via ear loops instead of bands that fit behind the neck and behind the head. Fit is severely compromised for any ear loop type mask. A mask that leaks is a mask that is less likely to protect.

One more big caveat to the KN95 mask. Due to the scarcity of N95 masks, there are many counterfeit KN95 masks being marketed. How do you know which one’s are legitimate? The packaging for a legitimate N95 filter will indicate that the FFR passed NIOSH 42CFR84 testing. Without NIOSH approval, the filter is suspect.

NIOSH approved filters have 9 different classifications. The N95 is just the most common. Here is a matrix to show all the approved filters available in the market.

Oil Aerosol RatingNot for oil aerosols*Resistant to oil aero**Oil aerosol Proof
95% EfficientN95R95P95
99% EfficientN99R99P99
99.97 % EfficientN100R100P100

*R series filters are only to be used in oil aerosol environments for up to 8 hours.

**Manufacturers of P series filters must specify how many hours that their filter is oil proof. Usually up to 24 user hours. Check the use limitations section of the instructions.

Airborne pathogens are not oily, so an N class filter is all that is needed. Airborne pathogens are between 1 and 2 microns in size and can be trapped easily by the 95 class filters. Adding efficiency adds breathing resistance. If you can get N95, buy N95 and take good care of them. Keep it clean and you can use it a good long time.

I just finished watching a YouTube video featuring a scientist named Joseph Allen (MPH, D.Sc.) of Harvard’s T.H. Chan School of Public Health. Joseph is stressing indoor air quality improvements in all buildings, both public and private. Joseph recommends a three-point approach to improving indoor air that will stop the spread of this and ALL OTHER viruses.

  1. Make sure that outdoor air is being circulated into buildings.
  2. Make sure the air is being filtered by a high efficiency filter. Joseph recommends a Minimum Efficiency Reporting Value (MERV) of about 80% efficient. The MERV13 or higher rated filter will achieve this efficiency.
  3. Make sure that air is being changed over in a structure at least 6 times per hour (most HVAC systems turn the air 1.5 times per hour).

Even for Ron, this is one long ramble. However, we are passionate that the answer to this pandemic not becoming endemic is not just a sliver bullet vaccine or shaming your fellow citizens about wearing or not wearing a mask. Systems can be improved, PPE should be a temporary measure not a way of living, just ask our friends at OSHA. Institute systemic improvements like cleaner indoor air and we all benefit.

Published by R Dub's Rub

Conversational BLOG writer and contributing writer for LocaLeben magazine. My BLOG entries represent observations that intrigue, amuse, inspire or stimulate my appetite.

One thought on “A Filter By Any Other Name

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

<span>%d</span> bloggers like this: