The Food and Drug Administration’s letter to the California lettuce industry stems from the 19 outbreaks of E coli 0157:H7 in the past decade, with one outbreak reported in Minnesota last month.
The letter provides guidance, but does not set out new regulations.

Although pre-washed salads are convenient for consumers, E.coli can contaminate lettuces at the farm level, primarily through floodwaters or high winds, or at the processing level, through poor hygiene conditions.
The Good Manufacturing Practice, set by the FDA, is a set of practices to help eliminate food-born illness risk factors. GMPs are currently mandatory for processors of fresh produce, but voluntary for packers.
According to the FDA, sanitation procedures are a key area for which regulations need to be tightened.
Last month, a final ruling requiring all manufacturers to register with the FDA was approved. The new law will allow the FDA to quickly locate food processors in the event of deliberate or accidental contamination of the food supply.