Three years after an E. coli outbreak, thought to be linked to spinach, took three lives and left 205 people sick, "Good Morning America" discovered that while the industry instituted new safety standards to prevent bacterial contamination, there are no requirements to test salad products before they get to market.
Some producers do test their products, but it is not always clear how robust those testing programs are.
The Food and Drug Administration oversees 80 percent of food in America, including spinach, but two years ago the FDA's Science Advisory Board issued a report saying the agency was "at risk of failing to carry out its mandate, leaving our citizens at risk of grievous harm."
Currently, FDA food inspectors visit food processors an average of once every decade, even though they carry out 7,000 inspections a year.
"We have to do better," FDA commissioner Dr. Margaret Hamburg told "Good Morning America." "The food safety programs at FDA have been woefully underfunded for years. There are serious gaps, and we can do better."
Leafy green producer Earthbound Farms, which was linked to the 2006 E. coli outbreak, is nestled in San Juan Bautista, Calif., in Salinas Valley, where 80 percent of U.S. leafy greens are grown.
"To find out that our product was associated with a national outbreak was absolutely devastating," Earthbound vice president Will Daniels told "GMA." "In hindsight there was more that we could do."
The root cause of the E. coli outbreak was never confirmed, but groundwater contaminated by wild pigs and cattle was the likely culprit. Earthbound learned a hard lesson, Daniels said: The salad maker was forced to overhaul its food safety program.
"Our testing programs are designed to catch those contaminated products," Daniels said.
Earthbound now tests all of its salad, including baby spinach, for harmful bacteria, like E. coli, not once, but twice before it heads to the supermarket, he said.
According to Daniels, the company processes approximately 2.5 million pounds of leafy greens every week and catches about 3,000 pounds of contaminated greens on the first round of raw product testing and another 300 pounds on the second round of end-product testing.
Other salad growers unconnected to the 2006 outbreak have new standards as well.
"Because of what happened in 2006, we had to take responsibility," said Joe Pezzini, chief operating officer at Ocean Mist Farms and chairman of the California Leafy Greens Marketing Agreement Board, which developed the new standards.
The new standards include audits, monthly water tests and a 400-foot barrier between cattle and salad fields. But critics say suggesting new standards is not enough.
"What we have now is a voluntary system, which is clearly not doing the job," said Erik Olson of the Pew Health Groups, Food Safety Programs.
Citing salad recalls since 2006, critics suggest more product testing.
The FDA provides "guidance" for California salad makers, but none of their suggestions are mandatory, creating a food safety system that Hamburg said is "inadequate."
"There's no doubt that FDA needs additional authorities," Hamburg said. "A system that's solely based on voluntary compliance isn't adequate. Especially since we know that there are some bad actors out there."
Experts say that washing loose-leaf lettuce will not always do the trick. The most thorough washing will not necessarily kill all of the bacteria. Rather, consumers should remove the outer leaves and wash each leaf individually.
When it comes to bagged or boxed lettuce, make sure that the leaves are not bruised or damaged and that they are refrigerated.
If the package says "pre-washed," "triple washed" or "ready to eat," avoid the temptation to wash the leaves again. Rewashing them could risk cross-contamination from your own hands or from bacteria in the sink or other kitchen appliances.