The decision comes months after the start of a nationwide salmonella outbreak and weeks into a flurry of peanut-related recalls that now includes a Beaverton-based company.
The Food and Drug Administration is working with the Justice Department to prosecute Peanut Corporation of America, Stephen Sundlof, FDA's director of food safety, told reporters during a conference call.
Sundlof said a shipment of the company's peanuts that contained metal shards and was rejected by Canadian authorities was returned to the U.S. last April and then destroyed by the company in November.
They tried to clean the metal shards out but it couldn't be done, said Domenic Veneziano, director of imports at the FDA.
An investigation of Peanut Corp's plant at Blakely, Ga., turned up two different strains of salmonella and evidence that on 12 occasions in 2007 and 2008 the company knowingly sold peanut products contaminated with salmonella, sometimes after getting a negative test by a private lab.
"I do find that shocking," said June Bancroft, epidemiologist with the Public Health Division in Oregon. "These factories are not really well maintained. They're just a big warehouse."
During the news conference, Dr. Robert Tauxe of the Centers of Disease Control and Prevention, said his agency had received reports of 28 new cases of people sickened since last Sunday.
That includes at least one in Oregon -- a young man in Yamhill County who became ill sick Jan. 16.
At least 530 people have been sickened in 43 states and in Canada and eight deaths have been linked to the outbreak, including one in Idaho.
"It's an unusually high number of deaths for a salmonella outbreak," said Bill Marler, a Seattle lawyer and expert on food poisoning cases.
The spurt of new sicknesses nationwide comes amid a doubling of Oregon's cases this month.
William Keene, senior epidemiologist at the Public Health Division, thinks the state will continue to tally new cases while the recall continues.
More than 400 items have been pulled off the shelves, with peanut brittle, roasted peanuts and other sweets added on Friday, including Peanut Butter Cookies and Cookie Bars made by Beaverton-based Arico Natural Foods Co.
This week the recall was expanded to include all products that Peanut Corp.'s Georgia plant sold since Jan 1, 2007, including dry- and oil-roasted peanuts, granulated peanuts, peanut meal, peanut paste and peanut butter.
"It is quickly becoming one of the largest and perhaps the largest food recall in U.S. history," Marler said.
Until Friday, federal officials had said consumers could trust well-known brands of peanut butter, but during the news conference Sundlof warned against "boutique brands" sold in small stores.
"We don't have concerns about the national name brands," he said, "but we know that some stores will purchase peanuts and grind them themselves which they sell as peanut butter."
In Oregon, Austin Toasty Crackers with Peanut Butter sickened at least one person, a boy in Clackamas County, who was ill this month.
Lab tests showed that the crackers from the boy's house, which were purchased at the Costco in Tigard, were contaminated with the same strain at the heart of the outbreak -- salmonella typhimurium.
Oregon health officials are now testing the same Austin crackers from the Yamhill County home for salmonella.
Although few food poisoning cases are rarely prosecuted at the federal level, Marler believes the Justice Department will take Peanut Corp. to court.
"It's highly likely that there will be a criminal prosecution in this case," he said.