By Guy Burdick
ASTM International, a standards-setting organization formerly known as The American Society for Testing and Materials, is developing a new specification for face coverings. The Centers for Disease Control and Prevention (CDC) has recommended cloth face coverings for the general public to reduce the number of COVID-19 cases, the Occupational Safety and Health Administration (OSHA) has recommended them in its workplace health guidelines during the pandemic, and four states now require them in emergency temporary standards for COVID-19.
The ASTM standard, which would create minimum design, performance, and labeling and care requirements for face coverings, is being developed by the subcommittee on respiratory protection at ASTM.
ASTM is targeting a February 2021 approval for the standard, Daniel Smith, vice president of technical committee operations said in an e-mail.
The current problem with cloth face coverings for both consumers and employers is that there are no regulations or consensus standards that apply to the variety of products available in stores and online, R. Bryan Ormond, assistant professor at North Carolina State University’s Wilson College of Textiles, said in an e-mail.
Ormond is testing fabrics and production masks at the college’s Textile Protection and Comfort Center, using and developing methods that build on those used by the National Institute for Occupational Safety and Health (NIOSH) to test respiratory protection. Most current test methods like NIOSH’s “work by challenging the ‘outside’ of the material and seeing how many particles enter the breathing zone through the material of the mask,” according to Ormond.
NIOSH, ASTM—A Nonregulatory Standard
NIOSH’s National Personal Protection Testing Laboratory (NPPTL) approached ASTM’s respiratory protection subcommittee about a standard that would encourage the use of commercially manufactured masks in the workplace. According to ASTM, the NPPTL’s opinion was that a federal rulemaking was not a viable option.
The ASTM standard primarily would evaluate the performance of face coverings as methods of source control—how well the products limit expelled particles from the wearer—according to the group’s description of the standard currently in development. However, the standard also would address a mask’s filtration capability to limit the inhalation of particulate matter.
The ASTM standard’s requirements would be intended for face coverings for the general public and workers outside of health care, according to the organization’s description of the standard. They would not apply to personal protective equipment (PPE) required under OSHA standards or any equipment used in healthcare settings.
Equipment and devices for infectious disease source control in healthcare settings, like surgical masks, are regulated by the Food and Drug Administration.
The ASTM standard for face masks would include:
- Design and general construction criteria, as well as criteria for head suspension;
- Bacterial and solid particle filter efficiency criteria, criteria for inhalation and exhalation breathing resistances, and sizing and fit-testing criteria; and
- Requirements for mask user instructions, including donning and doffing, sizing, cleaning, and recommended period of use, as well as packaging and labeling requirements.
The proposed standard would have two different levels of filtration performance, according to ASTM, based on test methods and requirements for breathing resistance.
The specification will increase “everyone’s confidence that the products that are available provide some level of performance that has been agreed upon by a very large group of industry, government, and academic subject matter experts,” Ormond said.
Having a standard from ASTM will “provide mask manufacturers with a set of requirements to aim for and a set of specifically selected test methods and parameters to show that performance,” according to Ormond.
Ormond’s recommendations for cloth face coverings are those made of “at least 2–3 layers of material, but not so many that it is hard to breathe through, and then something that can easily and repeatedly fit to the face.”
However, Ormond cautions that cloth face coverings “really are a last line of defense in the exposure controls toolbox.” He suggests that employers and facilities first ensure that administrative and engineering controls are in place. Those include social distancing, limiting the number of individuals in an indoor space, increasing building ventilation and air filtration, and hand-washing practices.