The New York Times is reporting today that the nation’s largest producer of bagged salads, Fresh Express, has switched from washing leafy greens with chlorine, the industry standard, to rinsing its produce with a blend of lactic and peracetic acids diluted in water.

As reported by Willliam Neuman, the story says the company, owned by Chiquita Brands International, calls its new wash solution FreshRinse and plans to market it to other producers.  Neuman states that the mild organic acids are already approved for use and common in food processing.

The move, the Times notes, comes on the heels of three recalls of Fresh Express packaged salad greens this year.  Random samples tested positive for Salmonella, E. coli and Listeria. 

Fresh Express told the Times its new cleaning solution can kill bacteria suspended in wash water 750 times more effectively than chlorine and that it is at least nine times as effective as chlorine in eliminating any bacteria contaminating the surface of leafy greens.

Packaged greens provide a quick, convenient way to make salads, which fosters more nutritious eating, but the safety of produce has been suspect, especially since an E. coli outbreak four years ago was linked to spinach.

Foodborne illness outbreaks related to produce have become larger and more common, according to the Centers for Disease Control and Prevention.  In the 1970s they accounted for less than 1 percent of all outbreaks with a known source and by the end of the 1990s that number had risen to 6 percent.

Five years ago, in a letter to produce growers, packers and shippers, the U.S. Food and Drug Administration identified 18 outbreaks of E. coli O157:H7 associated with lettuce, as well as the earlier outbreak caused by spinach, that it said had resulted in 409 illnesses and two deaths since 1995.  The FDA asked the industry to review operations and take steps to minimize risk.

Contaminated romaine lettuce has been responsible for several recent outbreaks, including an E. coli outbreak, which began in April this year and sickened 33 people.

The produce industry has been searching for an effective wash step that will make greens safer and help restore consumer confidence.