New ASTM Standard Establishes Design and Performance Requirements for Face Coverings
Last week, ASTM International published a voluntary standard that addresses aspects of face coverings, including their design, construction, particle filtration efficiency, sizing, and labeling. In a press release, the organization noted that the standard is intended to help workers and the public choose among various face-covering products.
ASTM F3502-21, Standard Specification for Barrier Face Coverings, was developed by ASTM’s committee on personal protective clothing and equipment.
“Members of the committee worked together to reach a consensus and address the gap that exists for barrier face coverings that are neither a respirator nor a surgical mask,” said ASTM International President Kathie Morgan. “The standard helps to benchmark products and will inform consumers when selecting face coverings for their intended use.”
In a webinar held on Tuesday to introduce the standard, Jonathan Szalajda, deputy director of the NIOSH National Personal Protective Technology Laboratory, explained that the wide variance in the performance of face coverings has created confusion among users.
“Over the past year, the term ‘mask’ has become a reference for anything an individual can wear on their face,” Szalajda said. “The standard allows for direct comparison of products to a baseline level of performance.”
Specifications in the standard demonstrate how much protection face coverings provide and how comfortable they are to wear. The standard requires face coverings to be designed so that “the large majority” of wearers’ inhalations and exhalations go through the fabric, aiding particle capture, and not around the sides of the mask, Szalajda said. He noted that face coverings need to be comfortable enough for people to be willing to wear them for long periods. The new standard also defines criteria that specify how products can meet requirements for source control.
The standard requires face coverings to cover the wearer’s nose and mouth and to minimize gaps where the fabric contacts the face. The portions of the material that contact skin must be non-irritating and non-toxic, and should not pose a flammability hazard. To meet the standard’s requirements, face coverings must also have a “retention system,” or a means of keeping the face covering in place for the expected period of use. Examples of retention systems are ties, head harnesses, and ear loops. In addition, manufacturers must demonstrate that a face covering can be worn by a wide variety of the population.
Other areas addressed by the standard include reusability, shelf-life, and laundering of face coverings. Szalajda noted that some face coverings can shrink or stretch when laundered, which potentially reduces their ability to filter particulate matter.
To comply with the standard, manufacturers must perform an analysis of how their face covering design limits leakage. An optional quantitative test described in the standard presents a modified version of the ASTM F3407 respirator fit capability test that manufacturers can perform to measure inward leakage through and around the perimeter of the face covering.
Areas not addressed by the standard include performance attributes such as flame resistance and the use of antimicrobial or antiviral materials.
Individuals who register on the ASTM website can view the standard online. Registration is free.