One essential step in sanitary design is that equipment should be self-draining.

Listeria is a common bacterium found in air, water and cold, moist places. Most of the Listeria bacterium is harmless, but Listeria monocytogenes is a dangerous strain that can cause an infection called listeriosis. According to the Centers for Disease Control, an estimated 1,600 people get listeriosis each year, and about 260 die. Certain populations, such as pregnant women and their newborns, adults aged 65 or older, and people with weakened immune systems are most at risk.

Since L. monocytogenes can thrive in cold, moist environments like meat and poultry processing plants, sanitation practices are essential. When sanitation practices are insufficient, Listeria can harbor in processing equipment, such as conveyor belts, slicers and dicers. Also, packaging machinery could harbor bacteria and transfer it to products.

Industry and government, including the North American Meat Institute Foundation, have made it a top priority to reduce the prevalence of Listeria in foods and prevent its spread in processing facilities. In 2002, NAMI’s predecessor, the American Meat Institute, established the Equipment Design Task Force (EDTF) to help develop operational and equipment sanitary design guidelines to minimize the spread of Listeria in processing plants. The EDTF, comprised of representatives from meat and poultry processing companies, created the sanitary design principles in consultation with equipment manufacturers, certifying organizations and government officials. The task force developed the “10 Principles of Sanitary Design” and in 2013, the guidelines were revised.

The 10 principles can be used in any food processing facility. According to the NAMI Foundation, the principles:

Provide an opportunity for equipment providers and equipment users to work together to identify issues of common concern;
Provide a forum to enable the sanitary design conversation to happen ahead of time rather than when equipment reaches the floor;
Create a standardized food safety focus for equipment evaluation;
Encourage and allow for innovation and drive continuous improvement in the industry.

10 Principles

The design of processing equipment used in meat and poultry facilities plays a crucial role in helping control pathogens and ensure safe, sanitary environments for food production. The “10 Principles of Sanitary Design” were created to help both processors and equipment manufacturers understand how they could work together to control pathogens.

The 10 principles are:

1. Cleanable to a microbiological level – Food equipment must be constructed as to prevent bacterial ingress, survival, growth and reproduction on both product and non-product contact surfaces of the equipment.

2. Made of compatible materials – The materials used for the equipment must be compatible with the product, environment, cleaning and sanitizing chemicals and methods of cleaning and sanitation.

3. Accessible for inspection, maintenance, cleaning and sanitation – All parts of the equipment must be accessible for cleaning without the use of tools.

4. No product or liquid collection – Equipment should be self-draining.

5. Hollow areas should be hermetically sealed – Hollow areas should be eliminated wherever possible or permanently sealed.

6. No niches – Equipment parts should be free of niches such as pits, cracks, corrosion, recesses, open seams, gaps, lap seams, protruding ledges, inside threads, bolt rivets and dead ends.

Sanitary operational performance – The equipment must perform so it does not contribute to unsanitary conditions.

Hygienic design of maintenance enclosures – Maintenance enclosures and human machine interfaces (push buttons, valve handles, switches and touchscreens) must be designed so food product, water or product liquid doesn’t penetrate or accumulate in the enclosure.

9. Hygienic compatibility with other plant systems – The equipment design must ensure hygienic compatibility with other systems such as electrical, hydraulics, steam, air and water.

Validated cleaning and sanitizing protocols – Procedures for cleaning and sanitizing must be clearly written and posted, and recommended chemicals must be compatible with the equipment and manufacturing environment.

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Staying sanitary

Joe Stout, former director of global product protection, sanitation and hygienic design at Kraft Foods and current president of Commercial Food Sanitation LLC, works with a number of equipment suppliers as well as processors in the industry to help them understand their respective roles in maintaining a sanitary environment, which will in the end ensure safe food for consumers. Stout led the taskforce in 2002 to develop the principles.

Joe Stout
Joe Stout

Almost 15 years later, Stout still feels the principles are relevant and important to the food industry today. “Not only are they pertinent, but they have been adopted with slight modifications for use in the produce, dairy and low-moisture foods industries,” Stout says. “I’ve been holding a series of Hygienic Design Summits between processors and OEMs (original equipment manufacturers) for the produce industry using the principles as support documents.

“Prior to Patrick Boyle (former NAMI president) retiring, I had a conversation with him about using the principles in other food segments and he was pleased to see them being used,” Stout explains. “The principles have been great for the food industry, not just for meat.”

Years ago, Stout helped conduct a Sanitation Symposium at Weber Inc. in Kansas City, Missouri. During the seminar he explained, “The industry now agrees pathogens are the enemy and there has to be zero tolerance for pathogens.” He further explained that sanitation involves more than simply wiping down equipment at the end of the day. “Sanitation has changed over the years; we now have to clean to a microbiological level.”

Cleaning to a microbiological level means having a step-by-step plan on a daily, weekly and monthly basis to clean equipment and the facility so pathogens don’t have a chance to harbor in processing equipment or contaminate the product, Stout said.

Stout further shares his expert opinion on sanitary design and its importance in the entire food processing industry.

MEAT+POULTRY: How do you describe the concept of sanitary design or clean equipment design?

STOUT: To keep it simple, sanitary design means making it easy to clean. I can give two examples. First, which is easier to clean, a clear top stove or a gas stove? It’s very difficult to clean a gas range following a holiday meal, but very easy to clean a clear top surface – one wipe does it. The second example is also simple. Instead of washing dishes by hand, how about a dishwasher? Put the dishes in and in 60 or 90 minutes the dishes, pots, pans and silverware are squeaky clean. Why can’t we do that in our plants?  We can and do, and it is called a CIP (clean-in-place) system. It may not be ideal for every process, but we need to look at this as an option.

To further explain, clean equipment design is a preventive approach to allow open access to observe, inspect, reach for cleaning and reach for sampling. Clearly with dry cleaning, where water and CIP is not typically used, one must rely on more traditional methods. If you can’t see it, can’t reach it, can’t sample it, then you can’t clean it or verify its cleaning. This is more critical in plants that do manual cleaning. Longer production runs could allow product to accumulate in hidden areas unobserved by operators, quality assurance or sanitation. This is vital from an allergen, microbial and pest control perspective.

M+P: In meat plants, what are the most important areas of concern when it comes to sanitary equipment design?

I believe the issues are the same whether in the dairy or meat industry in that the risk with pathogens comes after the process/kill step. If you can’t see it, you can’t clean it or sample it, and you can be surprised.

M+P: Designing a new plant is one thing, but what about meat processors who have older facilities that contain old equipment – what can they do to keep the plant and its equipment sanitary?

STOUT: Just a plan to replace poorly designed equipment in three years isn’t alone an option. The realization is apparent that to reduce risk requires routine periodic equipment cleaning, including deep tear-down cleans, and likewise for the infrastructure.     

M+P: What are the biggest challenges for the meat processing industry when it comes to sanitation and sanitary design? 

STOUT: The biggest challenge is realizing that a design problem exists. At times I think that the meat industry, and other industries for that matter, feel that the worst is behind them and the risk has been reduced with additives, advanced processing and packaging techniques and designs. History tells a different story.     

M+P: If the industry could do one thing to improve sanitation and food safety, what would it be and why?

STOUT: From a strategic perspective, I would like to have all industry participants become familiar with and understand the principles of facility and equipment design and fully take advantage of the learnings as they design buildings and equipment. After all, to make safe food, we start with a recipe, and the first ingredient is a clean plant and clean equipment, which is not guaranteed unless we have good designs. When there is industry understanding and full use of the principles, there will be contagious enthusiasm for continuous improvement in sanitary design.