LUBBOCK, Texas — The maker of “pink slime” suspended operations Monday at all but one plant where the beef ingredient is made, acknowledging that the recent public uproar over the product has cost the company business.

Craig Letch, director of food quality and assurance for Beef Products Inc., declined to discuss financial details, but said business has taken a “substantial” hit since social media exploded with worry over the ammonia-treated filler and an online petition seeking its ouster from schools drew hundreds of thousands of supporters. The U.S. Department of Agriculture has decided school districts may stop using it and some retail chains have pulled products containing it from their shelves.

The Maine Department of Education has said that the USDA beef it gets next year won’t contain the filler.

Federal regulators say the product, which has been used for years and is known in the industry as “lean, finely textured beef,” meets food safety standards. But critics call the product an unappetizing example of industrialized food production.

Beef Products will suspend operations at plants in Amarillo, Texas; Garden City, Kan.; and Waterloo, Iowa, Letch said. About 200 employees at each of the three plants will get full salary and benefits for 60 days during the suspension. The company’s plant at its Dakota Dunes, S.D., headquarters will continue operations.

The company, meanwhile, will develop a strategy for rebuilding business and addressing what Letch called misconceptions about the beef the company makes.

“We feel like when people can start to understand the truth and reality then our business will come back,” he said. “It’s 100 percent beef.”

The company last week took out a full-page ad in the Wall Street Journal defending its product.

It has also launched a new website, http://beefisbeef.com, which Letch says will help dispel myths about pink slime — a term coined by a federal microbiologist grossed out by it and now widely used by critics and food activists.

The lower-cost ingredient is made from fatty bits of meat left over from other cuts. The bits are heated and spun to remove most of the fat. The lean mix then is compressed into blocks for use in ground meat.