posted on 2021-04-16, 20:29authored byMelissa
S. Blevens, Homero F. Pastrana, Hannah C. Mazzotta, Candace Su-Jung Tsai
Amid the coronavirus disease 2019
pandemic, demand for cloth face
masks containing nanosilver has increased. Common product claims such
as “antiviral” and “antimicrobial” can
be attractive to buyers seeking to protect themselves from this respiratory
disease, but it is important to note that filtration capabilities
are the main factor to prevent virus transmission and that antimicrobial
ability is a secondary protection factor. Silver has long been known
to be antibacterial, and growing research supports additional antiviral
properties. In this study, 40 masks claiming to contain silver were
evaluated for substantiated antiviral and antimicrobial claims using
methods available to the public. Criteria for determining the validity
of substantiated claims included the use of patented technology, international
certification for antimicrobial and/or antiviral textile by ISO or
ASTM, EPA pesticide registration, and peer-reviewed literature. Our
analysis showed that, of the 40 masks, 21 had substantiated claims.
Using scanning electron microscopy (SEM), two of the substantiated
face masks (A and B) were examined for silver identification for further
confirmation. Mask A uses silver and copper ions attached to zeolite
particles; the zeolite particles discovered through SEM were approximately
90–200 nm in diameter. In mask B, particles of silver and titanium
at the 250 nm size were found. In conclusion, these certifications
or patents are not enough to determine credibility, and stricter regulations
by federal agencies on product testing for manufacturers that make
claims are necessary to ensure the efficacy of the product advertised,
as well as a cloth face mask inhalation standard.