Stewart Parnell at Commerce Committee hearing on Capitol Hill February 11, 2009 in Washington, DC. Getty Images/Mark Wilson / Staff Life in prison may seem like a harsh sentence for selling peanut butter — unless it ended up killing people.

That's the punishment federal officials have recommended for Stewart Parnell, the former CEO of the Peanut Corporation of America, who knowingly sold truckloads of the condiment from his Georgia plant even though he allegedly knew they were contaminated with Salmonella.

The tainted peanut products are thought to have led to the deaths of nine people and sickened more than 700 others, according to the US Centers for Disease Control and Prevention.

The US Probation Office also said that Michael Parnell, Parnell's brother and broker for the company's peanut sales, should receive 17.5 to 21.8 years in prison, and Mary Wilkerson, quality assurance manager at the company's Blakely, GA, peanut processing plant, should get eight to 10 years in prison. US Department of Justice attorneys supported the recommendations.

These sentences, which are scheduled to be decided September 21, "could be the most severe penalties ever imposed for food safety-related infractions since federal regulation of food started a century ago," Food Safety News reported.

Some perspective: Past penalties imposed for food safety-related infractions

A 2008-2009 Salmonella outbreak that sickened at least 714 people from 46 states was traced to peanut butter and peanut paste made by PCA. The deadly outbreak resulted in recalls of 3,913 products made by 361 companies, according to Food Safety News.

One of the victims was Shirley Almer, a 72-year-old grandmother who survived cancer twice, died shortly before Christmas Day 2008. Another was Clifford Tousignant, a decorated Korean War veteran and great grandfather who died in January 2009 at the age of 78, Food Safety News reported in 2012.

After a four-year FBI investigation, the PCA executives were indicted on 76 felony counts in February 2013. They were tried by a jury in July 2014 on charges including fraud and conspiracy, and selling misbranded and adulterated food into interstate commerce.

Last September, Stewart Parnell was found guilty on all but one count. Michael Parnell was found guilty on all counts except for those to do with introducing adulterated food into interstate commerce. And Wilkerson was guilty on one of two counts of obstruction, according to a government brief cited by Food Safety News.

A lawyer for the victims sickened by the contaminated condiment called the recommended sentence "unprecedented," while Parnell's attorney Ken Hodges called it "truly absurd," the AP reported.