Know the Health Risks Before Investing in an Antimicrobial Nano-Silver Mask (and What to Buy Instead!)

Center 4 Food Safety
5 min readNov 18, 2020


By Jaydee Hanson, Policy Director, Center for Food Safety & Julia Ranney, Research and Policy Associate, Center for Food Safety

Capitalizing on the novel COVID-19 virus and the need for face coverings, several companies are now selling masks embedded with nano-silver. They claim these products are “especially” antimicrobial due to the addition of nano-silver and therefore ensure enhanced protection from the virus. Nano-silver’s antimicrobial properties come from silver ions interacting with the DNA of pathogens to prevent reproduction and limiting key enzymes. Nano-silver has been found to kill a broad range of microbes that affect food. Its efficacy with regard to protecting against COVID-19, however, is less clear. Unfortunately, while nano-silver does have antimicrobial properties, its ingestion or inhalation by humans can cause significant harm and it is not approved for use in face masks by federal government agencies.

The Basics

Nano-silver is one of the most common and widely used antimicrobial nanomaterials on the global market. Nanomaterials are so small that a nanometer cannot be seen by an ordinary microscope. Due to their small size, they have different chemical, physical, and even biological properties than conventionally-sized materials. As such, the size and novel properties of nanomaterials are not properly understood with regard to how they interact with the human body’s immune and inflammatory response systems or the external environment.

Human Health Concerns

Due to their size, nanoparticles can enter the body and pass through biological membranes such as cell walls, cell tissue, and organs more . Following ingestion and inhalation, nanoparticles can easily cross the blood-brain barrier and produce to the barrier integrity. When , nanoparticles have been found to circulate through the body and reach potentially sensitive target sites such as bone marrow, lymph nodes, the spleen, the brain, the liver, and the heart. Overall, research has shown many types of nanomaterials can be toxic to human tissue and cell cultures , resulting in oxidative stress, inflammatory cytokine production, DNA mutation, and even cell death. The health ramifications from nano-silver are of particular concern because human exposure is increasingly widespread. Neither the EPA nor the FDA has approved nano-silver for use in face coverings or masks.

With the advent of nano-silver being put in and on face masks, excessive exposure is more and more likely. This is concerning because with the aforementioned nanomaterial health concerns, nano-silver ingestion and inhalation is dangerous. In vitro studies demonstrate that nano-silver is toxic to mammalian liver cells , , and even brain cells . Further, an overwhelming majority of studies report that contact with nano-silver causes abnormalities in basic cell functions. Nano-silver may also affect the liver and interfere with beneficial bacteria within the gut upon . Further, nano-silver may potentially compromise the ability to control harmful bacteria by increasing antibiotic resistance which may have an overall negative impact on human health.

Environmental Hazards

In tandem with human health concerns, nano-silver also has a negative impact on the environment. Silver in regular form is already known to have harmful impacts with high toxicity for fish, algae, crustaceans, plants, fungi, and bacteria. In fact, EPA already regulates silver as a pesticide and requires labeling stating silver pesticides as, “toxic to fish and aquatic invertebrates.” In nano-silver form, it can be many times more toxic. Additionally, the research found that washing nano-silver embedded clothing caused substantial amounts of nano-silver to leech into the discharge wastewater and eventually into the environment. Due to their greater surface area, nano-silver is more chemically reactive and more readily ionized than silver in large particle form. This is of concern because while that property makes nano-silver have strong antibacterial properties, it also has more toxic effects.

Regulatory Oversight of Nano-Silver

In 2015, EPA granted a petition filed by the Center for Food Safety seeking greater regulatory oversight of nano-silver products. In its response to the petition, EPA agreed that since nano-silver is used to kill microorganisms, nano-silver products qualify as pesticides. Further, EPA agreed that developers of such products must seek EPA review and registration before the products are allowed in the marketplace. Like many other nano-silver products, the companies selling these masks make unsubstantiated public health claims with regard to nano-silver and it’s protection against COVID-19. These claims can only be made on products that have been properly tested and are registered with the EPA. With regard to nano-silver masks, EPA should order these untested and unregulated products off the market and fine the companies until they perform stringent safety assessments by independent experts and submit them to EPA for registration.

Nano-silver mask providers to avoid:

Mask Recommendations

Due to the public health concerns regarding nano-silver exposure and the fact that nano-silver has not been approved for these uses by the FDA or the EPA, to protect against COVID-19 CFS advocates for the use of masks that do not contain nano-silver substances and is working to get EPA and FDA to pull unapproved masks from the market. CFS supports and recommends consumers follow CDC mask guidelines and purchase certified organic cotton masks that are either triple-layered or with a HEPA filter option for maximum protection. If you wear a gaiter, please be sure it is not single layered.

Triple-layer masks:

Filter Inserts:

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Originally published at on November 18, 2020.