Limiting and Eliminating Rodent Presence and Access

Rodents often are considered to be the principal pest of food and beverage manufacturers. “Rodent infestation and contamination is the most common reason for shutting down a food facility by a government agency,” said Copesan Director of Technical Support and Regulatory Compliance James Sargent. “A rodent infestation can easily result in company disgrace, loss of business, termination of blamed employees as well as managers, huge penalties, and even going out of business—which really means that everyone loses their job.”

Not only is it, thus, critically important for every food manufacturer to have a rodent management and prevention plan, but preventive controls are now being required by FDA as well as cGMPs.

“In this age of increased scrutiny, food and beverage processing plants cannot allow rodents inside a facility,” Sargent added.

Limiting Rodenticides Usage. However, such “increased scrutiny” has not only come from federal agencies that regulate the food and beverage industry, it also has come from EPA, which regulates all pesticides, including rodenticides. In 2011, a number of rodenticide risk mitigation measures took effect that limited rodenticide placement around buildings, thus limiting professional control efforts. Since then, the pest management industry’s work with EPA has enabled a loosening of the newly restrictive labeling requirements, but rodent prevention continues to be more of a challenge than in years past. (For more information on the EPA ruling, see EPA Limits Rodenticide Uses, sidebar below.)

Prior to the EPA label change requirements, rodenticides were often placed along fencelines and other outlying areas to intercept rodents before they could get near food facilities. But rodenticide labels must now state that the rodenticide can be used only within 100 feet of man-made structures—and, as with all chemicals, the label is the law. “Anyone that uses a rodenticide must follow the label directions and precautions exactly or risk a fine and/or jail time—if done deliberately or repeatedly,” Sargent said.

The restriction was put in place, said Bell Laboratories Regional Business Manager Sheila Haddad, to prevent secondary poisoning of non-target animals. The rule was originally set at 50 feet from a building, so the change to 100 feet from a man-made structure not only enables rodenticides to be used farther out, but also allows for their use around structures such as grain bins, storage units, etc.

However, Haddad added, according to scientific data, the normal rat range of travel is 450 feet, so prevention of rodent burrowing ideally would include placement of a rodenticide 450 feet from the facility. Thus, the extension from 50 to 100 feet was helpful, but still creates some challenges in rodent management. “But we have improvised and been able to work with that,” she said. “In areas farther than 100 feet, we make conditions a little less [attractive] for the rodent to be there and take preventive measures to reduce populations.”

The wording change from building to structure also was helpful, she said, as that opens up the ability to bait for rodents in other areas that are at risk but, by definition, would not have been considered buildings, as designated on the previous label.

In discussing the EPA ruling with pest management professionals, Haddad said she was told that the 100-foot rule can be limiting, particularly when a fence line program is needed for maintenance because of the rodent pressures from abutting properties that are over 100 feet from a structure. However, she has not heard of any situations that were completely unworkable since the ruling. “It seems like we’ve found the balance, for the most part, between precaution and efficacy,” she said. “The tougher rodent control situations require extreme creativity at times and a variable of intensity between cleanout and maintenance.  So whatever latitude we can achieve with the rules on the cleanout side (as a temporary measure) enhances the efficacy of a more restricted maintenance program in general.”

The label changes also impacted the use of over-the-counter products, cancelling or removing from the consumer market rodenticides that EPA said, “fail to comply with safety measures that EPA asked registrants to adopt by June 2011 and that are necessary to protect children, pets, and wildlife from accidental exposure to rodent baits.” While focused toward the homeowner, this also limits use by any non-professional.

Limiting Rodent Presence. With the new restrictions having been in place for more than a year, both pest control professionals and food facilities have implemented other practices and tools to prevent rodent invasion.

Outdoors, “many food and beverage companies are increasing their use of snap traps,” Sargent said. This is even being done within the 100-foot range where rodenticides can be used, but he added, “There is a debate about the advantages and disadvantages of snap traps versus rodenticides outdoors, but the most important advantage is that rodenticides can be relied upon to help protect a facility 24/7 while a snap trap may not be operational for some period of time, even a few hours after servicing. Imagine going for days or weeks with a trap not operational near a sensitive area.”

Making the property inhospitable to rodents also is key to limiting their presence, Haddad said. “Make it so it is not advantageous for rodents to be able to make comfortable burrows in the surrounding areas,” she said. Keep grass cut low, use crushed stone instead of mulch near the building, use perimeter stations as allowed.

Limiting Rodent Access. Whether one chooses to use rodenticides, snap traps, or other equipment or practices around the property, the key to preventing rodents in and around your food is limiting or eliminating their access. “You have to make sure that you have minimized any entryways for rodents—and insects,” said GMT Vice President of Sales Dave Colbert. This includes plugging of holes around pipes, electric and HVAC lines; sealing around dock doors and levelers—with custom solutions as needed, such as rail dock doors or other atypical entry points; and ensuring that all doors are kept closed when not in use. It is all about exclusion, “making sure that any hole you have is filled,” Colbert said.

To inspect for such holes, Sargent said, “Check outdoors at night for light leaking out small openings in your facility.” It is important to look high as well as low, as roof rats will access buildings by running across tree branches and overhead utility wires.

Any openings that are found should be sealed immediately, particularly as winter weather approaches and rodents seek shelter inside structures, Sargent said, adding, “Outdoor rodent devices, especially near doors, may need to be serviced more frequently or more devices added for a couple of months. This is also true any time neighboring land is harvested, cut, plowed, or burned.”

Because rodents also come into the food manufacturing facility with deliveries, the perfect scenario would be the opening of every single pallet and box on the dock to prevent the accidental carrying in of rodents—or other pests, Haddad said. But because that is not feasible or practical, it is important to spot-check deliveries as much as possible, and know and inspect for evidence of rodent presence in all deliveries.

Tracking and trending rodent incursion also is important to determine its means of entry—whether through an opening or with a delivery—and prevent further invasion. Ongoing documentation of the exact location of any rodent presence will help narrow down the potential entry point and method, and enable effective corrective action.

“You will never resolve it at 100%, that’s not the way life is,” Haddad said. But with due diligence and a thorough program of exterior baiting, exclusion, and interior prevention, you can limit rodent presence and access and eliminate those that do get past your defenses.

The author is Editor of QA magazine. She can be reached at llupo@gie.net.