3M Co. plants in Valley, Neb., and Aberdeen, S.D., are cranking out protective respiratory masks around the clock in response to the SARS scare, and nonstop production is being considered at the White Knight Engineered Products plant in Childersburg, Ala., according to the Associated Press.

Distributors to hospitals, equipment companies and retail stores nationwide say they can't keep the masks on the shelves.

Demand has risen to an all-time high since March 15, when the World Health Organization recommended masks to help stop the spread of severe acute respiratory syndrome. The highly contagious disease had killed more than 100 people, most of them in China and Hong Kong.

Many of the requests for masks come from people with relatives in Hong Kong and other parts of Asia, and from Canada, where there have been ten deaths.

Regin HVAC Products, Inc. of Shelton, Conn., is getting requests for as many as a million masks a day but can only get 10,000 masks a week from its manufacturer, company spokesman John DeWitt told the Associated Press.

Many of the requests are from safety equipment distributors, DeWitt said, but some come from individuals in the United States, Canada and Asia.

"People just want something to cover their faces," DeWitt said.