New York State officials are recalling 250,000 masks that they recently distributed to counties for schools, libraries and other public facilities after public questions arose over the quality of the masks.

The state recently gave out 5 million KN95 masks as part of a plan to thwart the omicron surge and support a newly reinstated mask mandate for indoor businesses. But on Thursday, the state Department of Health contacted counties where these masks were distributed asking them to “pull the masks in question” for immediate replacement, citing questionable quality in some.

“In the meantime, the Department of Health and the Division of Homeland Security & Emergency Services are conducting an internal review of masks currently in storage,” Erin Silk, a spokesperson for the New York State Department of Health, said in an emailed statement for WNYC/Gothamist.

The state issued the recall after performing a review of its mask inventory. It found as much as 5% of the masks they distributed are considered “questionable.” These masks were distributed to three counties: 180,000 sent to Monroe, 30,000 to Madison and 36,000 to Niagara. The state has contacted these counties and they will receive replacements.

In a statement, Monroe County officials acknowledged that the masks did not provide KN95 level protection but that they would work to replace them. In the meantime, it advised residents to use them anyway if they did not have access to higher quality masks.

While KN95 masks provide greater protection against the contagious omicron variant, the CDC warns that counterfeits are not uncommon.

But there are some ways of confirming authenticity such as looking for misspellings, decorative accents and clear markings from The National Institute for Occupational Safety and Health (NIOSH), the federal agency responsible for researching and recommending prevention against work-related injury and illness.

The CDC and NIOSH have developed a database to verify whether masks are approved by federal regulators.