Schools will get to opt out of "pink slime" beef

Issues can to go from a simmer to an explosion when content with broad interest — such as like food safety — is picked up and disseminated by widely connected people, said Marc A. Smith, director of the Social Media Research Foundation. These people act like "broadcast hubs," dispersing the information to different communities.

"What's happening is that the channels whereby this flood can go down this hill have expanded," Smith said "The more there are things like Twitter, the easier it is for these powder kegs to explode."

In this case, Siegel thinks the added element of children's school lunches could have set off this round.

"That's what upset me. This idea that children are passively sitting in a lunch room eating what the government sees fit to feed them and McDonald's has chosen not to use it, but the government is still feeding it to them," she said. "That really got my ire."

The USDA this year is contracted to buy 111.5 million pounds of ground beef for the National School Lunch Program. About 7 million pounds of that is from Beef Products Inc., though the pink product in question never accounts for more than 15 percent of a single serving of ground beef.

Beef Product Inc. stresses that its product is 100 percent lean beef and is approved by a series of industry experts. The company's new website, pinkslimeisamyth.com, rebuts some common criticisms of the product ("Myth 4: Boneless lean beef trimmings are produced from inedible meat").

The National Meat Association also has joined the fight, disputing claims that the product is made from "scraps destined for pet food" and other claims. The industry group also said that ammonium hydroxide is used in baked goods, puddings and other processed foods.

Association CEO Barry Carpenter, who has visited BPI plants and watched the process, said critics don't seem to have the facts.

"It's one of those things. It's the aesthetics of it that just gets people's attention," Carpenter said. "And in this case, it's not even legitimate aesthetics of it. It's a perception of what it is."