Nassau County officials say the business in Plainview was selling the masks out of a warehouse on Old Country Road.
The business was fined $25,000.
"If you are buying this or using this, if you are a healthcare worker or a grocery store worker and you are depending on this for your health and your safety, you need to know that it is a legit product," said Laura Curran, Nassau County Executive.
The CDC and the World Health Organization say healthy people do not need to wear face masks.
They say they do not offer any health protection benefits.
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