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FAQ – What certifications, validations, or paperwork should I look for when buying masks?

As you’re buying masks in these uncertain times, the last thing you want to do is to spend a lot on products that aren’t up to par. We hope to shed some light on how to determine whether the mask in your hands has, at least on paper, met the right standards.

First, we need to draw a distinction between masks manufactured for medical use and those for general use. Any product intended for medical use, such as in hospitals or in alternative care facilities, is screened and approved in the United States by the FDA. For the duration of the COVID-19 crisis, so that we save the critical supplies for healthcare workers on the frontlines, the general public is not encouraged to purchase products intended for medical use.

However, if you are buying masks for medical use, whether it is because you are procuring on behalf of a healthcare entity or municipality or you’re looking to make a donation, here are some documentations you need to look for:

  • A FDA-issued 510(k) clearance summary certificate – note, this is NOT a “FDA facilities registration” and should be specific to the product being sold. A facilities registration with the FDA is not sufficient. In fact, this registration can be purchased by any manufacturer for $5,236 and simply puts them in FDA’s database to begin the process of product approvals.  
  • A FDA-issued letter of 510(k) clearance – if the certificate is not available for any reason, buyers should look for a FDA-issued letter of clearance with the product precisely stated.
  • Listing on FDA’s EUA appendix of manufacturers – for the duration of the COVID-19 crisis, if you’re looking for procure respirators (N-95, KN-95, FFP2, etc.) for medical use from manufacturers who don’t yet have the full-out 510(k) clearance, verify that they are listed here. This is the list of manufacturers that have received an emergency use authorization (EUA) based on third-party lab reports or equivalent certifications from other jurisdictions. Note, a similar list doesn’t yet exist for surgical masks.
Here are two types of certificates frequently presented to buyers. The one on the left is a facilities registration and does not reflect a product approval. The one on the right presents an authentic approval

Now, let’s talk about masks made for general use. One important note is that many general-use masks in fact are made from the same medical-grade polypropylene and melt-blown fabric and carry much of the same properties as medical masks. However, the lack of “for medical use” designation means that the product has yet to undergo the FDA’s approval process. As a significant portion of manufacturers (including our family) that are producing PPEs came from industries far-removed from medical devices, they may not yet have had time to go through the reviews, which takes about six months. Given the mask shortage we are facing, how do we make sure that their products are made to standard?

Let’s start with disposable face masks. In the United States, there is no standard applicable for general use face masks. However, buyers looking to assure that the quality of general-use masks they purchase is on par with that of a medical-use mask, they should look for products assessed against a standard developed by the American Society for Testing and Materials (ASTM). This standard, ASTM-F2100, provides key performance metrics that medical face masks must meet.

ASTM permits manufacturers to self-represent that they meet the F2100 standard; manufacturers may take this step after they have self-tested their product per the procedures outlined in the standard. To improve their customers’ confidence in the product, they may also send their masks to a 3rd-party laboratory such as ICS Laboratories to obtain a test report.

There are generally five required components to the ASTM disposable mask test, and depending on its performance, the product will be assigned a “grade” from 1 to 3. Here are the five tests outlined by ASTM:

  • Bacterial filtration efficiency – essentially, how well the mask filters bacteria.
  • Differential pressure (breathability) – this makes sure your breathing won’t be affected.
  • Flammability – Masks should not catch on fire when exposed to open flames or other high heat sources.
  • Particle filtration efficiency – how well the masks filters 0.1 micron particles.
  • Synthetic Blood Penetration – essentially how well the mask resists fluids such as blood “seeping” through the mask.

Manufacturers that have tested their product to ASTM F2100 will happily advertise that, and you may find the resulting performance data on the product’s labeling or the manufacturer’s website. Note, however, that meeting the ASTM-F2100 standard does not automatically qualify the face mask as a mask intended for medical use. To market their products as being intended for medical use (e.g. as a “surgical”, “dental”, or “procedure” mask), manufacturers must still go through the FDA’s 510k process.

An example of ASTM label on a general-use mask box

Of course, across the world, there are other standards for the performance of face masks. In the EU, there is EN-14683. In China, YY/T 0969 is a less stringent standard for face masks for medical use, whereas YY 0469 is a more stringent standard, and GB/T32610-2016 standard applies to face masks for general use. To provide reassurance, manufacturers who’ve had their products validated will typically print the standard and relevant labels on their box. You should feel free to ask the manufacturer or distributor for laboratory documentation showing that the product meets the standards that are claimed!

Important to note – general use masks ARE NOT regulated by the FDA. Products distributed to the public that are labeled with a FDA logo are not authentic. In other words, the FDA has nothing to do with approving general-use masks and in fact, specifically forbids the use of its logo in any commercial product.

Here is a post circulated on China’s social media platforms informing manufacturers and the public that any packaging with the FDA logo is not authentic. The Chinese Customs and Clearance Administration has also implemented strong scrutiny and quality inspection control measures for all PPE exports since April 1st. Mislabeled packages or products not deemed to meet the standards will not make it out of customs.

Now let’s move on to N-95 grade respirators. In the United States, the efficacy of all N95 respirators is assessed against a standard developed by the National Institute for Occupational Safety and Health (NIOSH). All NIOSH-certified manufacturers of N-95 respirators are listed here, where you can easily verify their claims. As with disposable face masks, during a time of shortage, even if they aren’t NIOSH-certified, N95 respirators can be screened for adherence to NIOSH standards by third-party laboratories. Since the NIOSH certification process is also quite time-consuming, having masks validated by a lab to a NIOSH standard may be the best we can get. Here are the four tests that validation to a NIOSH N-95 standard would require:

  • Sodium Chloride (NaCl) aerosol challenge
  • Dioctyl Phthalate (DOP) particle penetration
  • Inhalation and Exhalation (breathability)
  • Valve Leak Test

Important note: Unlike with ASTM-F2100, manufacturers cannot legally self-attest that their mask is NIOSH N-95 compliant, even with lab tests. The product itself must be fully certified by NIOSH for a manufacturer to make this claim.

If you’re buying in bulk and the product is not NIOSH certified, carefully reviewing the lab validation data for these four tests will be crucial. These reports should reflect the numerical value tested, and not just simply state “pass” or “fail.”

This is an example of one part of a report from a basic validation study that the Chinese state authorities perform at customs before permitting export of a KN95 mask. Here, the filtration rate of different sizes of sodium chloride (salt) particles are measured.

Stay tuned for our next post on a few simple experiments you can perform at home to verify if your mask is effective or not.      

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