The city is cracking down on price-gouging merchants making money off coronavirus fears by declaring face masks in short supply — making it temporarily illegal to drastically increase their prices.

“Preying on people who are concerned for the health of themselves and their loved ones for a profit will not be tolerated in NYC,” said Department of Consumer and Worker Protection Commissioner Lorelei Salas, who announced the formal declaration on Wednesday.

“As we started to see empty shelves and more stores charging hundreds of dollars, we knew the city had to step in to prevent price gouging.“

Salas said she decided to check prices herself over last weekend and was charged a whopping $212 for a box of 10 masks by one merchant.

The new rule goes into effect Thursday. It expires in 30 days but can be extended.

Stores caught overcharging can be slapped with fines of up to $500.

One street vendor in Queens admitted Wednesday that he was selling $10 boxes of masks for $50.

Health Commissioner Oxiris Barbot said the city “doesn’t advise healthy New Yorkers wear masks” but added “they do provide a public health benefit in some situations.”

Last week, Amazon yanked more than 1 million fake and overpriced coronavirus products from its online marketplace – including tens of thousands of deals from merchants it believed were price gouging.