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Internal sanitation is frequently discussed as critcal to keeping pests from finding a hospitable environment (i.e., food, water, and shelter) in your processing plant. But you may be less aware of the external factors that draw pests to your facility, particularly in the summer when pest issues historically increase.

This includes not only common food pests, such as rodents and flies, but also occasional invaders, such as crickets and earwigs, which live outdoors but will enter structures in search of shelter from adverse conditions. While these occasional pests will not survive long indoors, even their brief presence (e.g., during an FDA inspection) will be seen as a potential food adulteration.

While the food safety or quality assurance manager may not generally see the exterior of the plant as within his or her realm of responsibility, the safety of the food being produced can be impacted by the condition of the exterior and its attraction to pests. Additionally, the plant’s grounds are addressed in the food safety provisions of the Food Code’s cGMPs, with some specific references to pests: Part 110, Subpart B, Sec. 110.20 Plant and Grounds states that “The grounds about a food plant under the control of the operator shall be kept in a condition that will protect against the contamination of food.” (http://1.usa.gov/1STwx98)

As such, GMP methods of adequate maintenance focusing on pests include:

  • Properly storing equipment, removing litter and waste, and cutting weeds or grass within the immediate vicinity of the plant buildings or structures that may constitute an attractant, breeding place, or harborage for pests.
  • Adequately draining areas that may contribute to the contamination of food by seepage, foot-borne filth, or providing a breeding place for pests.
  • Protecting food in outdoor bulk fermentation vessels by any effective means, including: using protective coverings, controlling areas over and around the vessels to eliminate harborages for pests, and checking on a regular basis for pests and pest infestation.

Thus, whether or not the exterior specifically falls in the domain of food safety, you need to ensure that the grounds are not attracting pests that can be further attracted into the facility. While exclusion (i.e., sealing gaps, repairing screens, keeping doors closed, etc., to reduce or eliminate pest access) is also a critical component of keeping pests out, this article focuses solely on the exterior grounds. (For information on exclusion techniques, read QA’s March/April 2015 article, Now Is a Good Time To Exclude Pests at http://bit.ly/1rlDymS).

EXTERIOR HABITAT MODIFICATION. What can the food plant do to make its exterior less attractive to pests? In most cases, the answer isn’t in the spraying of chemicals around the exterior of the plant. Rather it is a matter of habitat modification based on pest biology and behavior. Following are 12 practical tips for reducing pest attraction to the exterior of your facility. The first five focus directly on the specifications of the GMPs, while the others provide tips for decreasing your property’s appeal to pests.

Keep the perimeter of the food plant free of organic material.
© hansenn | Thinkstock.com; © Linda Johnsonbaugh | Thinkstock.com
Instead of landscaping with plants or mulch which can provide pests with food, shelter, and increased facility access.
© hansenn | Thinkstock.com; © Linda Johnsonbaugh | Thinkstock.com
  1. Properly store equipment. Most pests will take harborage about anywhere they can find shelter. If you keep equipment, crates and pallets, etc. unprotected outdoors, you not only attract pests seeking shelter, but you risk the chance of bringing those pests into the plant when the equipment is brought inside.
  2. Remove litter and waste. Piles of litter can provide shelter in which pests can easily hide, while waste is a readily accessible source of food. With such available resources, pests are also likely to decide your property is a great place to raise a family – with many pests able to breed at high rates.
  3. Cut weeds or grass. Both weeds and grass can provide shelter for a vast range of pests. Additionally, keeping a two-foot band around the perimeter of the facility completely free of grass, plants, or organic material will create a non-attracting buffer zone. Even standard landscaping ground cover, such as mulch and bark, can provide food and shelter for pests, and increase their access into the facility.
  4. Control moisture. In the heat of summer, moisture is one of the greatest of pest attractants – whether it be puddling in low-lying areas, overwatering of plants or mulch, stopped-up drain pipes, or other leaks. To prevent these, areas that accumulate water should be filled in or regularly drained; grounds built up so as to slope away from the building; downspouts directed away from the facility; and stone, rock, or other non-absorbent materials used for landscaping. 
  5. Use protective coverings, harborage elimination, and regular inspection to protect food in outdoor vessels. The GMP may be written as specific to bulk fermentation vessels, but it is the food safety-savvy facility that implements the practice throughout the property to protect any food products stored outdoors (e.g., crates of produce) and the property in general. Implementing Tips 1 to 4 to reduce potential pest harborage and checking on a regular basis for pests, pest infestation, and conducive conditions is just good pest management practice.
  6. Where landscaping is used, incorporate various native species to support a variety of insect species. Although this may sound counter-intuitive, maintaining a natural environment will help to reduce any single insect population, because the different species will be in competition for available food and harborage – which you will also have reduced through the other 11 practices of this list.
  7. Reduce pest attraction to lights. Some lighting is more attractive to pests and can draw them toward your building and to doors near which they are placed. This can be reduced by: 
    • Replacing standard mercury vapor lights with high-pressure sodium vapor or halogen lights. Bulbs with pink, yellow, or orange tints will be least attractive to the flying insects.
    • Placing lights away from the building and directing the light toward the area needing illumination.
    • Shading windows so that indoor lighting is less, or not, visible from outside.
  8. Control outdoor eating areas. If employees are able to eat outdoors, designate specific areas where they can do so, and restrict food consumption to those areas. Ensure that all food is picked up afterward, and spills or dropped food cleaned up immediately. Employees should also be told to not feed birds or other wildlife, as this simply attracts them, and secondary pests, to the area.
  9. Keep trash dumpsters closed, and trash areas clean and as far from the building as possible. It hardly needs to be said that trash and its odors will attract all sorts of pests – from flies to cockroaches to wild animals. Even when the containers can be set away from the building, employees should be cautioned to place trash only inside trash containers, and all should have pest-resistant lids/covers that are kept closed.
  10. Placing sticky traps around the facility can help control pests and monitor for their presence. Best placement is just inside potential entry points, particularly around dock doors. Pests attempting to make their way into the building can get caught on the adhesive of the trap, and if the traps begin to show significant numbers of catches, you will know that something is failing, and you need to implement further preventive controls.
  11. Exterior pesticides can sometimes be of benefit, but should be considered only after all other options fail – for two key reasons. The primary reason is because of the short-term aspects of pesticides used outdoors. Environmental conditions can quickly break down the active ingredients and reduce or eliminate the efficacy of the pesticide. Additionally, if the pesticide penetrates the exterior wall, it can reach and kill pests that seek shelter within the walls (such as stink bugs) which can then attract secondary pests or cause odors to emanate as they decompose. 

Internal pest control is an important component of any food safety program, but keeping external pests from coming into the facility in the first place is not only more efficient, it follows the new FSMA-focused, risk-based philosophy of implementing preventive controls rather than reacting after the fact.

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