WASHINGTON — The Food and Drug Administration on Dec. 20 proposed a rule that, if finalized, would require food facilities to address hazards that may be introduced intentionally by acts of terrorism. Domestic and foreign food facilities that are required to register under the Federal Food, Drug and Cosmetic Act would be required to identify and implement strategies to significantly minimize or protect significant vulnerabilities identified at actionable process steps.

”The goal is to protect the food supply from those who may attempt to cause large-scale public health harm,” said Michael R. Taylor, deputy commissioner for foods and veterinary medicine for the F.D.A. “Such events, while unlikely to occur, must be taken seriously because they have the potential to cause serious public health and economic consequences. The F.D.A.’s goal is to devise an approach that effectively protects the food supply in a practical, cost-effective manner.”

Under the proposed rule, a food facility would need to have a written food defense plan that addresses significant vulnerabilities in its food production process. Facilities would have to identify and implement strategies to address the vulnerabilities, establish monitoring procedures and corrective actions, verify the system is working, ensure personnel assigned to the vulnerable areas receive appropriate training, and maintain certain records.

The rule does not apply to farms and food for animals. The rule proposes exemptions based on the size of the business, sales and certain types of operations, such as holding and repacking food. The proposed rule would not apply to the packing, re-packing, labeling or re-labeling of food where the container that directly contacts the food remains intact.

The rule proposes staggered implementation dates, ranging from one year to three years after publication of the final rule, based on business size. “Very small businesses” that have less than $10 million in total annual sales of food would have to comply within three years of publication. “Small businesses” that employ fewer than 500 people would have to comply within two years. Other business would have to comply within one year of publication of the final rule.

The proposed rule, which is required by the F.D.A.’s Food Safety Modernization Act,   builds on the efforts of the Public Health Security and Bioterrorism Preparedness and Response Act of 2002. The F.D.A. estimates the annualized costs of the actions in the proposed rule to be about $370 million. The benefits of the actions are a reduction in the possibility of illness, death and economic disruption resulting from the intentional adulteration of food, but the F.D.A. said it is unable to quantify the benefits.