While the US government has standards for indicator organisms in milk, meat, drinking water and even swimming water, no federal standards are in place for these bacteria in salad greens, says the study. Several industry consultants suggest that an unacceptable level in leafy greens would be 10,000 or more colony-forming units per gram (cfu/g) or comparable measure, says the study.
For its analysis, Consumer Reports had an outside lab test 208 containers of 16 brands of salad greens, sold in plastic clamshells or bags, bought last summer from stores in Connecticut, New Jersey and New York. Among the findings: