Staff Photo by Elizabeth Fite / A knit mask made by a sock company and distributed by Gov. Bill Lee's administration is receiving criticism from Tennesseans.

NASHVILLE — As a North Carolina manufacturer on Tuesday defended the safety of millions of coronavirus masks it has sold to the state for use by Tennesseans, the legislative Black Caucus waded into the controversy and called for a "full investigation" into the coverings that have been treated with an anti-microbial pesticide.

Citing news reports, Black Caucus Chairman G.A. Hardaway, D-Memphis, said after conversations among group members as well as officials in Gov. Bill Lee's office and the state Department of Health, Lee agreed to stop distributing the masks.

But Hardaway said Lee "now needs to recall this obviously defective product and take it out of the hands of the general public.

"We know that many people in some of our more disadvantaged communities took advantage of the giveaway and now we need to protect them from the protection they believed we were providing for them," Hardaway added.

The Black Caucus' public entry into the controversy came as Lee's administration on Monday revealed it was halting distribution of the estimated 5 million masks the state had purchased from Renfro Corp., a manufacturer of socks and other cloth products which has a facility in Cleveland, Tennessee, employing some 335 people.

That came after a television news station reported that the mask was treated with a DuPont product, Silvadur, a silver-based product which is a registered pesticide with the Environmental Protection Agency.

In a statement, Renfro said Tuesday the masks are "harmless to human health and are serving the specific purpose outlined by U.S. and State of Tennessee health officials."

Company President and CEO Stan Jewell said in a Times Free Press interview Tuesday that the earlier news report last week, which led to Hamilton, Davidson and Shelby counties dropping distribution of the masks, did not accurately reflect the actual chemical being used by the company. It's a DuPont variant called Silvadur 360 FLEX.

Jewell said that has been approved by the federal government on items including sheets and pillowcases. While it is registered as a pesticide, Jewell said, that is because it is used to curb microbial growth that causes foul odors. But it is not the type of pesticide used, say, to kill insects or rodents, Jewell emphasized.

Moreover, Jewell said, after the company gets the chemical to produce the sock masks, it strongly dilutes the chemical to produce "a very, very dilute version of the product." Safety labels generally refer to chemicals in their concentrated form, he added, noting that sodium chloride in toothpaste can be dangerous in its original form.

"We developed a really great mask," Jewell said, noting it has "everything you want in a protective mask and we think it's important communities get the correct information."

Phil Williams, the WTFV news reporter who wrote the initial story on the Silvadur issue, later tweeted that the "only difference" he sees in the label is the percentage of silver and he questioned whether it was appropriate to use over one's mouth.

Tennessee Health Commissioner Lisa Piercey later said after speaking with company officials "we are reassured with what we've seen so far."

She also noted that "we are pursuing some independent testing. But we don't have any reason to believe that they're harmful at this point. But the main point is wear a face covering that you're comfortable with."

Use is up to people's "discretion," Piercey said,

In a statement last week, DuPont called Silvadur "a safe and trusted technology used to control bacteria, mold and mildew that cause odors on fabric for more than a decade with no adverse health effects."

The company also stated "the antimicrobial material applied to treated fabrics, such as face masks or coverings, are at such low levels that the use of the fabric poses no risk to consumers."

DuPont also said the chemical "has been approved by EPA to control bacteria, mold and mildew that cause odor on fabrics. Based on EPA regulations, Silvadur is registered with the agency and classified as a pesticide."

The company also stated the independent International Oeko-Tex Association conducted a "thorough evaluation of the technology, and confirmed Silvadur 930 Flex Antimicrobial is recognized and listed as an Active Chemical Product, with biological activity, as a formulation that has been assessed to be harmless to human health, provided it is used as indicated and designated."

Oeko-Tex Association is comprised of what its website describes as 18 independent research and test institutes in the field of textile and leather ecology in Europe and Japan with contact offices in more than 60 countries. The partner institutes have joint responsibility for the development of test methods and limit values that form the basis for a variety of standards.

When the Lee administration rolled out the Renfro masks, critics immediately questioned how effective they would be given the porous, sock-like material used to make them.

An independent analysis of the masks by the Knoxville News Sentinel, however, found them to be on par with other cloth face masks at preventing the spread of the coronavirus that causes COVID-19.

Contact Andy Sher at or 615-255-0550. Follow him on Twitter @AndySher1.