Masking Children for School

The highly infectious Delta variant of COVID-19 is on the rise just as the school year begins. Vaccination is one of the most powerful tools to protect students and broader school communities. However, there is currently no authorized COVID-19 vaccine for children under 12. We must rely on other mitigation measures to protect them. In July 2021, the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics (AAP) both updated their guidance to recommend universal indoor masking for everyone in school, regardless of vaccination status, along with other mitigation measures. What masks should parents select to protect their children as they return to school? 

Table of Contents:

Disclaimer: MakerMask does not endorse any products. All products mentioned in this blog post are for illustration purposes. All products are purchased directly from the manufacturers, and MakerMask receives no compensation from them. We do not participate in affiliate links programs.  

What mask should children wear to school?

The best mask for children is the one they will keep on their face throughout the school day. 

A good mask balances fit, filtration, and breathability:

  • Fit: A well-fitted mask fully covers the mouth and the nose with no gap on all edges. Opt for a mask that properly fits the individual child, and consider adding a nose wire to reduce any gap around the bridge of the nose. For many kids with smaller faces, a child size mask may provide better fit than standard adult masks.
  • Filtration: A mask with higher filtration can better block pathogens from traveling in and out through the mask. Choose masks with tested filtration performance, especially in higher risk situations.
  • Breathability: Compared to adults, children’s developing lungs breathe in a larger volume of air per bodyweight per day. A more breathable mask may be necessary to accommodate this higher respiratory rate. 
    • Avoid masks with valves. While exhalation valves improve breathability, they enable pathogens to travel out through the mask.
    • Double masking is not recommended for young children due to breathability concerns.
Balancing Fit, Filtration, and Breathability. All three factors–fit, filtration, and breathability–must be taken into account when choosing a mask. A mask with high filtration but poor fit, or a mask with high filtration but that is not very breathable, actually encourages leakage (airflow follows the path of least resistance), thereby significantly compromising the filtration efficiency. Check for mask fit around all edges–the nose, the sides of the face, the chin/jaw–by visual inspection and by feeling around the edges. If glasses fog up significantly, it is a good indicator of leakage. 

Mask Selection

When selecting a mask, consider the risk level in the school setting, taking into account local transmission rate, vaccination rate, the school’s mitigation strategies, and your own risk tolerance. 

For low risk situations (e.g., low COVID-19 local cases, universal masking in school and comprehensive mitigation measures), you have many mask options. 

For higher risk situations (e.g., high local transmission rate, no universal masking in school, and minimal mitigation measures), consider a well-fitted breathable mask with high filtration for optimal protection. Search for a mask that excels at both source control and at protecting the wearer.

1. Disposable High Performance Filtering Facepieces (N95s, KF94s, KN95s, and FFP2s)

When fitted and donned properly, a disposable filtering facepiece is a good option for high risk environments due to its superior filtration.

In this post, only N95s are referred to as respirators. Other non-NIOSH-approved high performance filtering facepieces are referred to as “filtering facepieces” or “masks”.

 Consider the following disposable filtering facepieces for children: 

  • N95: Any valveless NIOSH-approved (U.S.) respirator (not available in children’s sizes)
  • KF94: Any Korean-made KF94 (children’s sizes available)
  • KN95: Carefully evaluated* KN95 (children’s sizes available)
  • FFP2: Carefully evaluated* FFP2 or higher (not available in children’s sizes) 

*Beware that many untested filtering facepieces are marketed and sold to the public. This report provides excellent insights and examples on vetting high performance filtering facepieces/masks. When selecting disposable filtering facepieces, consider these factors: 

  • Stay with well-established, conventional designs
  • Select masks with credible test reports for filtration and breathability
  • Shop from reputable, authorized dealers.

N95 (Not Available in Children’s Sizes)

A NIOSH-approved N95 respirator filters 95% of 0.3 micron particles. An N95 has undergone rigorous inspection and certification set by the National Institute for Occupational Safety and Health (NIOSH). N95’s are not manufactured for children, neither are they recommended for young children due to the extremely tight fit on the face which can cause discomfort and strangulation hazard. Some N95’s come in different sizes, and the smallest adult size may fit adolescents and older children who can safely and correctly follow donning (put on) and doffing (take off) procedures. Beware of counterfeits

KF94 (Children’s Sizes Available).

A KF94 combines the comfort and breathability of a lightweight structured mask with high filtration capability similar to that of an N95. South Korea’s Ministry of Food and Drug Safety rigorously tests and oversees KF94’s manufacturing and distribution. KF94 comes in various children’s sizes. The 3-dimensional shape of a KF94 provides plenty of mouth space and is comfortable for extended wear. Unlike an N95 respirator, a KF94 mask typically comes with ear loops instead of head straps. Figure 1 shows a 10-year old wearing a KM’s Dr. Puri KF94 size small and the modifications to improve fit. 

Photo of a child wearing a KF94
Figure 1. Modifications on Dr. Puri KF94 (size small) to improve fit. 
Why was this mask selected? This mask has credible test reports for filtration and breathability, including the South Korean government’s rigorous KF94 certification and distribution control, a test report by CDC’s National Personal Protective Technology Laboratory (NPPTL), and a review and test by US mask manufacturer Armbrust.

KN95 (Children’s Sizes Available)

A KN95 mask is a cross between a respirator and a face mask that meets the KN95 standard regulated by the Chinese government. KN95 comes in children’s sizes. Unfortunately, quality control for KN95 does not appear to be uniform, and NIOSH reported that some KN95s might not meet the actual KN95 standard. As a result, it can be more challenging to find sources of reliable KN95s than KF94s.

FFP2 (Not Available in Children’s Sizes)

FFP2 is a filtering facepiece meeting the European EN 149 standard, and is comparable to a N95, filtering 94% of 0.3um particles. FFP2s are readily available in Europe through trusted sources, but their availability is limited in the US. As with N95s, it is not marketed for children. Adolescents may fit the adult size, and may find the flexible structure of most FFP2s to be comfortable. Beware of counterfeits or fake certificates. 

2. Disposable Medical Masks

An advantage of disposable medical masks (surgical and procedural style masks) is that they are commonly available in children’s sizes. Look for a medical mask with ASTM labeling to ensure it meets the minimum criteria for breathability and filtration set by the ASTM F2100 standard.

Although some medical masks boast high filtration materials, the actual filtration efficiency during use could be significantly lower due to leakage around the edges on these loose fitting masks. The Clapp et al study and the CDC guidance show that with slight modifications, mask performance is improved.  Figure 2 shows a 10-year old wearing two different sizes of Armbrust medical face masks, with and without modifications to improve fit. 

Child wearing medical mask
Figure 2. Modifications on Armbrust’s Medical Mask to improve fit (blue: child size and grey: adult size).
Why were these mask selected?They are ASTM F2100 Level 3 masks with credible test reports for filtration and breathability that are made in the USA and FDA-listed. In addition, they have been tested by third party labs.

FDA Listed Children’s Masks

The FDA regulates pediatric medical masks and maintains a list of children’s masks that have been “FDA-cleared” or “FDA-listed”. However, the FDA does NOT approve medical masks or respirators for adults or children. So if any mask claims to be “FDA-approved”, that should be a warning sign. See Making Sense of Mask FDA Designations for a detailed explanation.

The table below includes select examples of “FDA-Listed” children’s masks (manufactured in North America) from the FDA’s database along with the testing performance listed on the manufacturer’s website. 

FDA-Listed Pediatric Masks* Ages Style Material Filtration BFE (3um) Material Filtration PFE (0.1um) Breathability (mm H2O/cm2)
Halyard Child’s Mask (USA) 4-12 Pleated ≥ 98% ≥ 99% < 2.0
Armbrust Child’s Mask (USA) Not specified Pleated ≥ 99% ≥ 99% < 5.0
Medicom Pediatric Mask (Canada and USA): ASTM F2101 (Level 1) 4-12 Pleated ≥ 98% ≥ 99% < 5.0
Lutema Kids M95c (USA) < 12 Fitted 99.9% 99.8% Tested using a different metric
Lutema Kids M3PFMC (USA) : ASTM F2101 (Level 3) 4-14 Pleated 99.9% 99.8% 4.8
* Select North American Mask Manufacturers listed in the FDA’s “Establishment Registration and Device Listing” database for pediatric/child mask (Product Code: OXZ)

3. Reusable Masks (Commercially Available)

There are many child-size reusable masks in the market. However, many do not offer data on filtration and breathability, nor do they employ high filtration materials to offer optimal protection for the wearer in high risk situations.

To help consumers and manufacturers, the American Society for Testing and Materials (ASTM) has established a national standard for Barrier Face Coverings (ASTM F3502). See this blog post for details. The criteria in the ASTM F3502 standard provides insights to consumers when comparing mask options and can be used to characterize both disposable as well as reusable masks. Currently there are not many masks in the market tested to this fairly new standard.

For higher risk environments, look for masks exceeding the ASTM F3502 Level 2 criteria in filtration (i.e., ≥ 50% of 0.3um particles), and preferably at Level 2 breathability (≤ 6 mm H2O)

Tips for Selecting Commercially Available Reusable Masks

Additional tips on finding a high performance reusable mask:

  1. Test Reports: Check that the product has reliable test reports. Use the ASTM F3502 criteria as a guidance on evaluating any filtration and breathability reports. In addition, this blog post provides insight on how to interpret filtration data. 
  2. Minimum Three Layers: Look for masks with at least 3 layers per the World Health Organization’s guidance–an inner layer of hydrophilic material, a middle layer of filter, and an outer layer of hydrophobic material.
  3. Adequate Filter Size: The filtering material should span the entire breathing area to provide the optimal protection. Beware of removable filters, which are often too small to span the entire breathing area, allowing pathogens to travel through any unfiltered area.
  4. No Exhalation Valves: Many high performance reusable masks are designed as anti-pollution masks. Often they come with exhalation valves, but the valves are unsuitable for containing the wearer’s pathogens in a pandemic. 
  5. Washability: Check the manufacturer’s washing instructions. Some of the high performance anti-pollution masks restrict washing of the filter, which may not be suitable for pandemic use. Many high performance masks recommend hand washing ONLY. If you intend to machine wash your masks, verify that it is acceptable with the manufacturer’s instructions.

Example: Evaluating Test Reports of High Performance Reusable Masks

These are some examples of very high performing reusable cloth masks with published test reports showing filtration >95% at 0.3um. Although these masks have not yet been tested against the new ASTM F3502 standards, the results are consistent with exceeding the new criteria for Level 2 filtration.

  • Vogmask is a pioneer in high performance reusable anti-pollution masks. The company conducts rigorous testing, and publishes reliable test reports.  It features excellent filtration and fair breathability. Breathesafeair has a comprehensive review on this mask as an anti-pollution mask, but the fit, filtration, and breathability reviews are useful for our application. 
  • Enro published test results on filtration but not breathability (Actual lab reports on filtration available upon request). New York Times Wirecutter has conducted testing through Colorado State University, suggesting good breathability on the Enro mask, but no detailed test report is available to the consumer for verification. 
  • HappyMasks published some test reports on filtration but not breathability. Although the submicron (at 0.3um) test report is not posted, it is available upon request. Breathesafeair has a comprehensive review on this mask (as an anti-pollution mask) suggesting good breathability.  

Figure 3 shows a 10-year old wearing reusable masks with and without modifications–an Enro Mask (size XS) in the left photos, and a Vogmask (size M) in the right photos.  

Child wearing reusable vogmask and enro masks
Figure 3. Enro Mask (size XS) and Vogmask (size M)

4. DIY Reusable Masks

If you cannot find a mask that fits well on your child, consider making your own fabric mask from high performing materials, such as spunbond non-woven polypropylene (NWPP), which balances breathability and filtration. Use at least three layers of fabric per the World Health Organization guidance. 

Maker Mask has tested two fabric mask combinations that are consistent with the ASTM F3502 Barrier Face Covering standard:

  • Mask with 3 layers of spunbond nonwoven polypropylene (NWPP x 3)
  • Mask with a 3-layer combination of cotton and spunbond NWPP (cotton-NWPP-cotton)

These fabric combinations offer good filtration and breathability. Coupled with a good fit, masks made from these fabric combinations could be considered excellent barrier face coverings per ASTM F3502, and outperform many reusable fabric masks in the market. 

Figure 4 shows a 10-year old wearing two different styles of custom-made fabric masks, both utilizing fabric combinations that are consistent with the ASTM F3502 Level 2 criteria. 

Child wearing reusable masks
Figure 4. Custom-made mask with high performing materials, head strap secure fit. Custom 1 source: Sophie Passmore 3D/Boxy NWPP Mask. (Size: As shown in the video). Custom 2 source: Iris Luckhaus’ Hybrid Cloth Mask. (Size: Width XS and height S).


Select a mask for your child according to your local COVID-19 risk level and your family’s needs. Whichever mask you choose, it is paramount to keep it clean. If a mask is doing its job properly, it will collect a plethora of pathogens over time. After each use, disposable masks should be safely disposed of, and reusable masks should be washed according to the manufacturer’s instructions. See this post for general information on washing and disinfecting. 

We hope the tips in this post will equip you for back-to-school mask shopping!

Masking Children for School

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