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The Case Against Qualitative Respirator Fit Testing

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Are you or your company currently using qualitative respirator fit testing (e.g., the procedure that relies on the ability of the test subject to sense saccharine exposure)? If so, how can you be 100% positive your respirators are properly fitted and therefore effective at protecting you and your co-workers?

 

Current regulations allow qualitative fit testing methods for half-face respirators including disposable facepieces. However, the test itself depends wholly on the test subject’s widely-varying sensitivity to the challenge agent (typically saccharine) and worse, his or her veracity. There are absolutely no defensible metrics developed during a qualitative fit test. 

In contrast, a quantitative fit test measures a metric which is not influenced by the test subject, or in other words, is completely objective. Any record of a qualitative fit test contains only a subjective response regardless of how closely the process follows the protocol outlined in 29 CFR 1910.134.

To place this in a different context, let’s imagine it as a court case. Since it’s apparent we live in an increasingly litigious society, civil erroneous behavior or actual wrongdoing (or as we understand the legalese, a tort) is frequently addressed in lawsuits. 

Can you imagine a scenario in which a worker who has suffered some sort of respiratory insult might bring suit against an employer claiming that he or she was inadequately protected under the employer’s Respiratory Protection Program (RPP)?

 

If the employer were using a Qualitative Fit Test, the plaintiff testimony might be similar to this:

         Plaintiff’s lawyer: “Do you have a formal Respiratory Protection Program?”

         Person responsible for RPP: “Yes, we do.”

         PL: “Does it include a requirement to perform fit testing of the respirators you   provide?”

         RPP person: “Yes, it does, in accordance with OSHA guidelines as stated in 29 CFR 1910.134

         PL: “What sort of fit testing do you provide?”

         RPP person: “We use a Qualitative Fit Test Protocol.”

         PL: “Could you describe the protocol?”

        RPP person: “Well, briefly, it consists of placing a hood over the test subject’s head and squirting saccharine into the hood to see if the test subject can taste it while he is performing a series of exercises…”

         PL: “And what sort of data does this test provide?”

         RPP person: “Well, it tells us whether or not a test subject can taste the saccharine…”

         PL: “And if he or she can taste it, what does that mean?”

         RPP person: “That means that they have failed the fit test”

         PL: “And if they can’t taste it or if they tell you that they can’t taste it, what does that mean?”

         RPP person: “It means they passed.”

         PL: “So all you have is a subjective answer based on the ability of the test subject to taste a challenge agent, and what’s worse, the truthfulness of that answer?”

         Defense Lawyer: “Objection! Your Honor, the plaintiff’s lawyer is leading the witness.”

         Judge: “Sustained.”

         PL: “I’ll re-phrase my question. Do you have any proof, any actual metric that demonstrates exactly how well the respirator fit my client?”

         RPP person: “Well, we keep records of who was tested, when it was done, and what the result was.”

         PL: “So you don’t actually know how well the respirator fits my client?”

         Defense lawyer: “Objection!”

Now, if you were a juror in this trial, how would you feel given that explanation? Would you have doubts about the legitimacy and accuracy of the qualitative fit test? There’s a good chance most of us would be skeptical of this form of fit testing.

If, on the other hand the employer were using a Quantitative Fit Test, the plaintiff testimony might go as follows:

         Defense lawyer: “Do you have a formal Respiratory Protection Program?”

         Person responsible for RPP: “Yes, we do.”

         DL: “Does it include a requirement to actually measure how well a respirator actually fits the user?”

         RPP person: “Yes, it does, in accordance with OSHA guidelines as stated in 29 CFR 1910.134. We refer to this measurement as aFit Test’.”

         DL: “What sort of ‘Fit Test’ do you provide?”

         RPP person: “We use a Quantitative Fit Test Protocol.”

         DL: “Could you describe the protocol?”

        RPP person: “Certainly! The test uses an instrument that is capable of measuring the concentration of ultrafine particulates in the ambient atmosphere and dividing that number by the concentration of ultrafine particulates in the test subject’s breathing zone while the test subject is performing a series of exercises designed to stress the respirator/face seal.” The instrument makes these measurements and computes a “Fit Factor” which is mathematically related to the actual “Protection Factor”

        DL: “How do you know the instrument is working properly?”

        RPP person: “We have the instrument calibrated yearly according to the manufacturer’s recommendations, and we perform a validation check prior to and after each series of fit tests. The validation check ensures that there are a sufficient number of particles, that the detector is working properly, that there are no leaks in the system, and that the switching valve between ambient and in-mask sample is functioning properly.”

        DL: “And do you have records to support this?”

        RPP person: “Of course. All of the test data including the validation test data are automatically written to our database.”

        DL: “So you can produce actual, objective, defensible metrics that describe the condition of the instrument used in these measurements and the fit of the respirator?”

        RPP person: “Of course.”

As that same juror, how does this testimony differ from the first? Feeling more certain about the effectiveness of a quantitative fit test? It’s likely we all would. 

Now, given the choice, which method would you want your company to utilize?

Obviously, this is not a real court transcript (yet) and we’re not lawyers, however, the point we’re trying to make is clear. There is a huge risk in attempting to defend qualitative fit testing which generates absolutely zero defensible, objective metrics. 

Quantitative Respirator Fit Testing not only saves lives, it can save companies thousands of dollars in capital costs for potential lawsuits, should employee respirators not fit correctly. 

There is an old saying from Britain that goes like this: “He hath spoil’t the barrel for a ha’penth of tar!”

Want to learn more about Quantitative Respirator Fit Testing?

 

 

Respirator Fit Testing Mandate: Yea or Nay?

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Very few people like mandates, but there are many that make sense. For instance, restaurants are required to meet certain standards of cleanliness and sanitation to stay open and functioning. Commercial airline flight crews have to demonstrate proficiency in their ability to fly passenger-carrying aircraft by earning an Airline Transport Pilot rating and a First-Class Medical certificate. Healthcare professionals must be certified and licensed in their field in order to be able to practice.

Anyone out there want to eat at a disreputable restaurant, fly with an untrained pilot, or be operated on by an unlicensed doctor? Not likely.

We tend to take these things for granted, but in reality, these protections exist because they are mandated.

Why are Fit Testing Mandates Required?

The common misconception about respirators (including and especially N95 disposable respirators) is that if someone wears a respirator, he or she is protected from whatever toxic or infectious agents are in the ambient atmosphere in which the person is working. While this may be true, the only way to be sure the wearer is protected is to know that the correct filtration is employed and that the respirator fits!

OSHA has mandated in 29 CFR 1910.134 that whenever a respirator is required to be used to protect an employee (and there are some very specific requirements in the regulation), the respirator must be fit tested to ensure that it actually fits the employee sufficiently well to achieve a minimum protection( fit) factor.

Respirator Fit Testing Mandate Protects Us

Fluid dynamics tells us that a fluid (like air) will flow through the path of least resistance. If the respirator does not seamlessly fit the face of the wearer, a very large part of the air entering the breathing zone will have done so by bypassing the filtration and entering past the margins of the respirator, most likely through gaps around the edges. Toxic vapors, infectious aerosols, and particulates will be carried into the breathing zone along with this air flow. The only way to be sure that this does not occur is to rigorously test the fit of the respirator, and the only way to unambiguously do so is by using a Quantitative Fit Test.

Wearing a respirator that doesn’t fit is dangerous. This is obvious, but even worse, it can create a false sense of security on the part of the wearer. He or she may then take risks they might not otherwise have taken while wearing improperly fitted pieces of personal protective equipment.

What Is the best way to test the fit of a Respirator?

A Quantitative Fit Test (QNFT) such as is produced by the AccuFIT 9000 series of instruments does not depend on the ability of the test subject to detect a challenge agent such as saccharine. QNFT is completely objective and produces a defensible metric that can be referred to by the employer and test subject as proof that the respirator fits and will do the job it was designed to do.

As we said, few people like mandates, but this one, Respirator Fit Testing, saves lives, so we vote Yea!

N95 mask types

The Real Problem With Mask Mandates

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N95 mask types

Even N95 Masks Require Respirator Fit Testing

With the rise of the omicron variant, many States and businesses are enforcing mask mandates.

Whether or not you agree with these mandates, the real question is…do they make sense when many masks are ineffective?

Based on our experience, we think not.

Not All Masks Protect The Wearer

Cloth masks do little or nothing to protect the wearer from infectious aerosols, and mandating wearing these makes no sense.

Even surgical masks that do a pretty good job of protecting everyone else from the wearer aren’t 100% effective. Fluid mechanics tells us that any fluid (like air) will flow through the path of least resistance, and since surgical masks do not actually seal to the face, most of the incoming air enters around the mask rather than through it.

It’s the Fit That Counts

What does make sense instead of issuing a mask mandate, is requiring that well-fitted N95 masks be made available, especially for medical and emergency-response personnel. And the key phrase here is “well-fitted” which means that the N95 respirator (brand, model, and size) must be fit-tested!

A user could be wearing the best-filtering N95 in existence, but if the respirator doesn’t fit, it’s effectively useless, allowing more air around than through the mask. Even worse than providing little to no protection, the ill-fitting mask gives the wearer a false sense of security, potentially leading them to take risks they might never have if they’d known their respiratory system was unprotected.

How Does Respirator Fit Testing Work?

There are two types of fit testing available when it comes to most respirators – qualitative and quantitative.

Qualitative fit tests rely on a test subject’s ability to sense a challenge agent (usually saccharine) while wearing their mask. But unfortunately, this produces absolutely no defensible metric that can be referred to for proof of effectiveness of fit. This type of testing is completely subjective and therefore can lead to a questionable result as far as the actual fit of the respirator is concerned.

Quantitative Fit Testing is completely objective, so the results can be relied upon to accurately measure whether or not the N95 (or other respirator) actually fits the person on whom it is being tested. Once the fit test shows a passing score, the healthcare worker or emergency response worker can take comfort in knowing they are truly protected.

Mandate fit tests for at-risk personnel, not useless cloth masks.

To learn more about quantitative fit testing, check out our Quantitative Fit Testing Guide here.

What is Quantitative Respirator Fit Testing?

By Blog Post

Quantitative respirator fit testing measures how much air leaks into any tight-fitting respirators. Each fit test is performed by using a machine that calculates measurements with one of two methods: ambient aerosol (CNC) or controlled negative pressure (CNP). For nearly 30 years, there were only two manufacturers capable of performing the OSHA fit test protocol.

Which Method is Best?

The CNP method requires the wearer to hold their breath and stand still for the duration of the test, while the CNC test allows the wearer to be tested in a dynamic manner.

With over 75 years of combined respirator fit tester experience, we know if a respirator is going to leak, it will most likely do so while the wearer is talking, breathing, moving their head and/or performing basic work functions, not while holding still.

Respirators are used in a wide range of industries, from chemical and medical fields to first responders, oil and gas industries, and even in the military. Making sure they fit the user perfectly is essential to each user’s health and safety.

We use quantitative fit testing with the CNC method on all of our instrumentation to ensure the most accurate fit test measurements.

What Respirators Can Be Tested?

Our instruments work with all types of respirators, including full and half-face respirators, filtering face piece respirators like N95 masks, and even disposable masks and respirators. During the test, the user is required to move around and breathe as normal.

The AccuFit 9000 Pro Is The Most Effective

In fact, our own AccuFIT 9000 Pro is the world’s most accurate tool for quantitative respirator fit testing. Compliant with OSHA’s streamlined 2019 CNC protocol as well as ANSI, CSA and HSE, it works with all respirator types, including N95, P100 and N99, FFP1, FFP2 and FFP3.

This model comes standard with several unique features, including standalone mode, built-in wifi, and some unique programming, which allows us to be the first respirator fit tester on the market with wireless operator mode. Wireless operator mode allows a person to control one to four units with a tablet, with independent start and stop times. All this can be done concurrently as instructions are relayed to the fit test subject on the built-in display of the instrument.

The AccuFIT 9000 Pro also has the option of a separate battery pack for portable testing in the field. Plus, it’s backed by a three-year warranty.

Using AccuFit 9000 machines like the AccuFit9000 Pro, fit testing takes just minutes and ensures a direct fit every time.

How Viruses (like COVID-19) Can Affect Qualitative Respirator Fit Testing Results

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The Qualitative Respirator Fit Test is a method that relies on the ability of the test subject to detect a challenge agent such as Saccharin. It has been in use for decades and predates the evolution of Quantitative Fit Testing methods and equipment.

Qualitative testing assumes that if any amount of the challenge agent penetrates the respirator/face seal the test subject will taste or smell it. The test is conducted while the test subject is wearing a hood into which the challenge agent is aerosolized. There are several factors associated with this method which can and have been proven to occur, chief among which are:

  1. Extreme variations in different subjects’ ability to taste or smell the challenge agent
  2. Truthfulness or confusion of test subjects in reporting whether or not they can sense the challenge agent
  3. Onerous physical requirements in the protocol and now, continuous decontamination between tests which tend to encourage “short cuts” in the execution of the test, and
  4. The complete lack of any defensible metric such as the Fit Factor data that is collected and recorded by the Fit Test device when performing a Quantitative Fit Test.

The first concern, that of the wide variation in the test subjects’ ability to detect the challenge agent, is exacerbated by the generally recognized fact that many persons who are infected with the SARS CoV-2 virus which causes Covid-19, even if asymptomatic, can experience greatly reduced olfactory sensitivity. One can easily imagine a situation in which an asymptomatic but infected individual would be tested by using a challenge agent for which they have a greatly reduced ability to sense.

A 2020 article in Scientific American by Leslie Kay, Ph.D. addresses both the mechanism of this olfactory dysfunction and the fact that it can exist in asymptomatic individuals.

The concern is that the already-problematic qualitative test now has another reason to distrust the results; virus-induced olfactory dysfunction (medical term: Anosmia).

A Quantitative Fit Test using the new streamlined OSHA 2019 standard can be conducted in about two and a half minutes.  The results are completely objective, produce a defensible metric, and are not affected by any impaired sense of taste or smell.

NIH recently released this information which presents a very serious statistical evaluation of the reduced sense of smell in the population of the US.

An infographic summarizing information and statistics on the sense of smell in U.S. adults over age 40.

For more information about the advantages of Quantitative Fit Testing compared to Qualitative, please feel free to contact us here.

How N95 Masks Really Work

By Blog Post

There is a lot of misinformation about the way N95 respirators work and in fact what the designation actually means. In order to understand the  AAC/CPC method of fit testing, it is really helpful to first understand the filtration mechanisms that occur in the Filtering Facepiece Respirators such as the N95 series.

We recently found this video, which does an excellent job of explaining the physics of the N95.

In fact, we were so impressed by the very straightforward explanation of the filtering mechanisms that we asked the production company for permission to link to the YouTube video, which they graciously granted.

The video contained in this link is meant for educational purposes only and was produced by ‘MinutePhysics’ who are solely responsible for its content and messaging. You will be redirected to the MinutePhysics YouTube Channel to view this very informative piece about the physics and performance characteristics of N95 respirators.

How Long the COVID Virus Can Live on Surfaces

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One of the many important things to know about the particular strain of coronavirus which is the etiological agent of the current pandemic is the length of time the virus can remain infectious when it is in the environment. This exceptionally well written and documented letter was published in the New England journal of Medicine which gives some pretty clear answers which everyone should know.

Unfortunately, on relatively inert surfaces such as plastics and stainless steel the virus is sufficiently robust to have a half-life such that it probably is infectious up to 72 hours after deposition. Copper surfaces are more active, and the viability seems to be about 4 hours. What is most concerning (at least to me) is that apparently the virus can remain viable in aerosol droplets for up to 3 hours.

This is why healthcare workers who may be exposed to infected (and infectious) individuals should seriously consider respiratory protection.

We at AccuTec-IHS want to once again stress the fact that merely wearing a respirator (such as disposable N95’s, N99’s or N100’s) isn’t enough. The respirator must have been properly fit-tested. A quantitative fit test such as the fit test performed by the AccuFIT 9000® can truly prove that the mask fits and that the person wearing it knows how to deploy it properly.

We at Accutec-IHS are monitoring the situation constantly, and are doing all we can to keep up with demand.

Questions or comments? Let us know here.

The Difference Between CNC & CNP Fit Testing

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Video Transcript

I understand that respirator fit testing is becoming more important all the time. It looks like there are two methods for performing quantitative fit testing, CNC and CNP. What’s the difference? You’re right. There are essentially two methods currently in use to perform quantitative fit testing of tight fitting respirators. First, the most widely used method is the ambient aerosol method using condensation nuclei, counting CNC, which can best be described as challenging the seal of the respirator with naturally occurring ultra fine particulates which mimic gas molecules due to their extremely low mass characteristics. And secondly, the controlled negative pressure or C N P method, which pulls a slight negative pressure inside the mask and then measures the exhaust to determine how much more air must be pumped out in order to maintain that same low pressure. Both methods sound pretty reasonable. Is one better than the other? Well, let’s look at some specifics.

The way the CNP system measures the pressure inside the respirator is by using a very sensitive pressure transducer. When the pressure rises, the system runs the vacuum pump and measures the amount of air in the exhaust, which is theoretically identical to the amount of air which is leaked past the respirator seal. So far so good. Whoa. If the pressure transducer is all that sensitive and the test subject is breathing, doesn’t that change the volume and pressure in the breathing zone? Well, yes, so the test subject has to hold his or her breath while the leak rate is measured. Furthermore, the test subject cannot move at all or the pressure will change slightly and the system will interpret that change as a leak. Wait a minute. Don’t people actually move and breathe when they are wearing respirators and if a person is wearing a respirator performing his or her job, aren’t they actually challenging the seal more than they would be when they are completely immobile?

Again? Yes. That’s why the exercises in the CNC protocol actually exist to challenge the seal in a dynamic manner. Obviously if you are moving and performing a workplace task, you are challenging the seal and the control negative pressure system doesn’t do this. Nope. The measurements are only made while the test subject is completely still and not breathing. Then why does the CNP protocol include these exercises? Good question. Probably so that the test will appear to actually be testing the fit while the subject is moving, but it actually doesn’t know well, how does the ambient aerosol method work? The system measures the concentration of ultra fine particulates in the ambient atmosphere and then measures the concentration of these ultra fines, which are also frequently referred to as respirable particulates in the breathing zone of the respirator. While the test subject is actually moving and breathing. Then this system measures the ambient concentration, again, computes an average of these two values and compares that value to the concentration inside the breathing zone.

The resulting ratio is the fit factor, which is a real measure of how well the respirator actually fits. Wow, so the important thing is that the actual measurements are performed while the test subject is moving and breathing, correct? Correct. Oh, wait a minute. How do these particulates get removed from the breathing zone? That’s one of the beautiful things about using ambient aerosols as a challenge agent. They are naturally absorbed by the lungs. That’s one reason they’re called respirable particulates. If the respirator being tested is set up with a HEPA filter in the inlet in about a minute, the concentration ACE and tonically approaches zero then any new particulates observed in the breathing zone penetrated past the respirator seal. What about the time it takes to perform a fit test? Isn’t the controlled negative pressure method quicker? Back in the day it was. However, there’s a new protocol which has been approved by OSHA, which allows a CNC test to be performed in less than three minutes. Well, what about filtering face pieces like in 90 fives or in one hundreds CNC works very well for filtering face pieces. CNP doesn’t. Why not? Have you ever tried to pull a vacuum on a disposable Mask.

How to Setup the AccuFIT9000 Fit Testing Machine

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Video Transcript

Hi, I’m Wesley with Accutec-IHS. The AccuFIT9000 is a new instrument for performing respirator fit testing which depends on measuring the fit of a tight fitting respirator by comparing the ratio of the respirable particles in the breathing zone, with the concentration of these ultra-fine particles in the ambient atmosphere. This technology is called condensation particulate counting. To learn more, watch the video condensation particulate counting on the AccuFIT9000. 

          Let’s ensure the instrument is working properly, remove the instrument from the carrying case and locate the power supply AC cord, alcohol capsule sample tubing, and HEPA filter. Plug the power supply into an electric outlet. Connect the power supply and plug the connector into the port on the back panel of the AccuFIT9000. Next, remove the alcohol wick assembly from the capsule and place it on a clean surface. Then pour reagent grade isopropyl alcohol which is supplied with the instrument into the capsule so that the level of liquid is above the bottom line and below the top line. Replace the alcohol wick into the capsule and allow the alcohol to saturate the wick. This takes about two minutes. Remove the wick assembly from the capsule and tap off any excessive alcohol. Then remove the storage cap from the AccuFIT9000 alcohol port and replace it with the saturated alcohol wick. The locating pin and camming groove on the cap will guide the wick into its proper location. Now attach the sample tube to the a AccuFIT9000 making sure that you attach the blue tube to the blue inlet and the clear tube to the silver Inlet. Attach the HEPA filter to the clear tube making sure that the arrow showing flow direction is pointing toward the tube. Now press and hold the on/off button on the AccuFIT9000 until it illuminates with a red light. Allow the instrument to complete its warm-up and internal self checks. This takes about a minute and then will automatically transition to the opening screen.  The on/off button will now illuminate green. Touch the administration icon and then select the database icon using the drop down arrow. Highlight demo and then touch the load button. A message should appear telling you that the database demo is successfully loaded into active memory. Please note that the demo database does not allow you to perform all of the functions to test the instrument. It does not allow you to add names, respirators, or protocols to memory, nor does it allow you to save any results obtained. Press exit and then the return arrow on the previous screen. This returns you to the opening screen.

          Now it is time to test the functionality of the AccuFIT9000. Touch the icon labeled validation check, remove the HEPA filter from the clear tube and press start. The AccuFIT9000 will now measure the ambient particles and produce account. The validation check will now ask you to replace the HEPA filter into the clear tube and press next. The validation check will proceed automatically to check that there are no internal leaks in the system, that the switching valve is functioning properly, and that the unit can calculate the max fit factor. You have now demonstrated that the AccuFIT9000 is performing as designed. To shut down the instrument, hold the on/off button until it flashes red and green and touch the yes box. It is very important to remove the alcohol cartridge and replace it with the storage cap. Failure to remove the alcohol cartridge can result in alcohol contamination of the optics. Replace the alcohol cartridge into the   capsule. This ensures that there will be no spillage and that the alcohol cartridge will be ready to use the next time you want to perform fit testing. If the AccuFIT9000 is to be stored in the carrying case, remove the sample tube and power connector, and place the cutouts in the protective foam insert and position the instrument appropriately.

How to Protect Against COVID Spread With Respirator Fit Testing

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Both CDC (Centers for Disease Control) and WHO (World Health Organization) have now recognized the 2019-nCoV coronavirus outbreak as being serious. One of the more concerning developments is the fact that 2019-nCoV has shown to be capable of human-to-human transmission. This was first documented in this country today, January 30, 2020, in Chicago where a recently returned visitor from China has infected her husband.

Because of this demonstrated ability of the new virus to effect human-to-human transmission, CDC has issued guidelines for health professionals which can be accessed at the bottom of this page: https://www.cdc.gov/coronavirus/2019-ncov/cases-in-us.html

One of the recommendations the CDC Document mentions is the use of respiratory protection. Typically, healthcare facilities use N95 Filtering Facepieces (FFP’s) or powered air-purifying respirators (PAPR’s). PAPR’s need to be cleaned and disinfected after each use, while FFP’s are discarded after each exposure to airborne pathogens, so the chances are greater that N95 FFP’s will be the respiratory protection devices of choice.

AccuTec-IHS would like to remind users that it is imperative that fit testing in accordance with 29CFR 1910.134 be performed for each user of the tight-fitting respirators (in this case N95 FFP’s). From personal experience we can state that even though the techniques of donning, testing, and wearing an N95 FFP appear to be logical and straightforward, in reality if the user has not been adequately trained, the mask is worse than useless because it imparts a false sense of security to the wearer. This training should incorporate a Quantitative Fit Testing device where real-time and completely objective measurements can show the user graphic proof of protection while the mask is being adjusted to fit. (This real-time information is for training purposes and does not constitute a fit test.)

OSHA has recently approved a much faster Quantitative Fit Test protocol for the filtering facepieces (N95) which takes less than three minutes to perform. A legal Qualitative (i.e., subjective fit test) requires about twenty-three minutes. 

The AccuFIT9000 is capable of testing many of the commonly used N95 masks.

Please contact us to determine if the AccuFIT 9000 is suitable for your fit testing requirements.