On Friday, the Food and Drug Administration issued a proposed anti-terrorism rule that would require the largest food businesses in the U.S. and abroad to take steps to prevent their facilities from being the target of intentional attempts to contaminate the food supply. It is the sixth rule to be proposed under the sweeping mandates of the Food Safety Modernization Act, which addresses the safety of foods that are produced domestically or imported to the U.S.

“The FDA is unaware of an event where the food supply was adulterated with the goal of inflicting massive public health harm,” an FDA statement says. “While such events are unlikely to occur, mitigating strategies proposed in the rule can continue to ensure the safety of the food supply. The proposed rule is intended as a preventive measure.”

The FDA is proposing a targeted approach focused on processes within a food facility that are most vulnerable to attack. Under the proposed rule, a food facility will be required to have a written food defense plan that addresses significant vulnerabilities in its food production process. They will then need to identify and implement strategies to address those vulnerabilities, establish monitoring procedures and corrective actions, verify that the system is working, ensure that personnel assigned to the vulnerable areas receive appropriate training, and maintain documentation of those efforts.

This is the first time the FDA has proposed a regulatory approach for preventing intentional adulteration of the food supply. Since Sept. 11, 2001, and the subsequent passage of the Public Health Security and Bioterrorism Preparedness and Response Act of 2002, the FDA has developed guidance and tools to help industry protect the food supply against intentional adulteration. The proposed rule builds on those efforts, as well as the steps industry has taken, the FDA says.

The proposed rule includes limited exemptions based on size of business and certain types of operations, such as holding and repacking food. It does not apply to farms and food for animals, and the holding of food, except in liquid storage tanks. Also exempt are businesses involved in the packing, re-packing, labeling, or relabeling of food where the container that directly contacts the food remains intact.

The FDA is also proposing staggered implementation dates for the proposed rule based on business size, ranging from one year to three years after publication of the final rule. The rule is available for public comment until March 31, 2014.Owing to industry concerns, the FDA also announced it will re-propose earlier draft rules that are part of the Food Safety Modernization Act.