The Food and Drug Administration says its new guidelines would make the food Americans eat safer and help prevent the kinds of foodborne disease outbreaks that sicken or kill thousands of consumers each year. The rules, the most sweeping food safety guidelines in decades, would require farmers to take new precautions against contamination, to include making sure workers’ hands are washed, irrigation water is clean, and that animals stay out of fields. Food manufacturers will have to submit food safety plans to the government to show they are keeping their operations clean. The long-overdue regulations could cost businesses close to...