It’s three strikes or they’re out for growers, shippers or handlers who violate food safety standards designed to prevent future E. coli outbreaks. The new policy is expected to be passed later this month in Sacramento by the California Leafy Greens Marketing Agreement Advisory Board, set up by the industry earlier this year. The stringent policy was outlined Tuesday before hundreds of growers and handlers who gathered at the Salinas Community Center. The three-strikes policy is the backbone to the 150-page agreement, intended to safeguard against another E. coli outbreak like the one that killed three people late last summer and sickened more than 200 others across the country. So far, hundreds of handlers, growers and shippers, an estimated 99 percent of the industry, have signed on to the agreement, and ultimately they will be awarded a “seal of approval” if they follow its chief guidelines.