Challenges for the food industry seem to increase every day. Product recalls occur due to a variety of reasons from allergen contamination to microbiological issues. Investigations into many of these incidents have led to an underlying issue with the facility design, a problematic system or component of the system. Evaluating sanitary design criteria has become an effective way to reduce or, in many cases, prevent many of the issues related to these events.
STICK TO THE BASICS. Too often, when the words “sanitary design” are mentioned accountants start sweating and fabricators delight in anticipation of high-cost materials. Although this is sometimes the case, more often than not, it just takes the right information and application of basic principles to avoid costly issues. Remember, the cost of a piece of equipment does not always reflect its value as a well-designed and manageable asset.
Sanitary design is the use of clearly defined methods and specifications for the design, fabrication, and installation of facilities and equipment to eliminate or reduce recognizable risks of contamination from microbiological, physical, and chemical sources. Design standards should:
- Enhance the functionality of the system and not inhibit it.
- Improve the ability to reduce risks of product safety concerns.
- Reduce time required to properly clean the unit.
- Provide for the selection of the appropriate materials for fabrication of the facility and/or equipment.
- Effectively isolate potential threats to product safety.
The requirements for considering sanitary design criteria originate in the Good Manufacturing Practices, specifically parts 110.20 Plant and Grounds, 110.35 Sanitary Operations, 110.37 Sanitary Facilities, and 110.40 Equipment and Utensils. Though specifications are not included, the GMPs require that you consider the food safety requirements of the system based on your particular needs. So when questioned about your plant design, you are on solid ground to respond that it is a requirement of the GMPs.
To discuss sanitary design in its entirety would take far more space than this article allows. There are entire books written on the topic that offer insight into specific issues you may have experienced. Engineering for Food Safety and Sanitation by Thomas Imholte is an excellent resource that provides valuable information on facility construction and design and equipment installation for a food plant.
Additionally, there are organizations that have pooled a collective wealth of experience and developed standards to assist the industry. A few excellent resources for managing the potential for microbiological, physical and chemical contamination are the Baking Industry Sanitation Standards Committee (BISSC), 3A Standards, National Sanitation Foundation (NSF) and Produce Equipment Standards. Many of these are registered ANSI Standards and available to act as guidance.
UNDERSTAND THE ISSUES. Experience has taught me that mistakes made during the fabrication and installation of systems are often the result of simply not understanding the issues. With this said, an essential element of any project, regardless of size, is an open line of communication and a never-ending emphasis on getting it right. You have to ask the “whys” and the “what ifs.” Some of the best sources of information are the very people who have worked with the current equipment for years.
Food plant construction and equipment are a major investment. Any possible savings should be considered. Unfortunately, decisions are often made to cut expenses that provide short-term savings, but result in very expensive long-term costs. For example, plants often select a mild steel catwalk decking rather than aluminum or stainless steel. If the material is installed in an area where wet washing is required, it results in the paint on the mild steel becoming a maintenance problem and potentially entering the process flow. The cost to manage this issue quickly surpasses the investment in a more durable material capable of tolerating the activities needed.
One historic problem occurring in the food industry is that companies often fail to construct a building for their process, and instead put a process in an existing building. This causes issues with drainage systems, equipment spacing and general construction that can create sanitation nightmares. Having a clear set of criteria for the selection process can reduce these concerns. For example, if you are considering relocating to an existing facility because of the need to upgrade due to growth, decide if it has the capability for further expansion at a later date. If it doesn’t, your search for yet a larger facility may reoccur in a few short years. It is essential that the selected facility be durable enough for the process.
STRUCTURAL CONSIDERATIONS. Understanding that a dusty process needs to have a limited number of product collection points helps determine the type of construction materials used. Building designs that have numerous ledges or areas where product will collect will result in sanitation or pest issues. You have to decide if the building is worth the long-term costs of managing these issues?
Partition walls can present numerous concerns. Wall voids provide the capacity for product collection, resulting in potential pest issues or micro issues from mold growth. Existing construction should be evaluated for previous penetration into the walls and the effort needed to correct this. Clear procedures need to be developed and implemented for future penetrations.
Electrical systems for buildings and equipment are often overlooked. Electrical systems that aren’t dust proofed or water-resistant may be adequate for a warehouse, but would cause serious concerns for a food processing area. There are national standards and rating systems (NEMA Standards) for electrical systems that need to be considered to avoid potential issues.
Floor drains are another common challenge for many food plants. The best floor plans and layout can be side railed by a last-minute equipment addition or a change in the use of an area. In a micro-sensitive area, the ability to easily clean and manage floor drains is critical. Design characteristics must include drains that are constructed with a smooth, easily cleanable surface and preferably equipped with a water seal. When needed due to water capacity issues, trench type drains should have liners durable enough for the materials they handle. This type of drain construction can be a particular challenge during cleaning since special equipment or materials are needed to remove the residue that often accumulates on the top section of the drain lines where micro or pest issues tend to concentrate.
EQUIPMENT CONSIDERATIONS. Easily accessible equipment can be quickly exposed for inspection and cleaning using simple tools.
As shown in the pictures above, the better option is a reinforced guard cover with a single securing point that can be removed with a simple tool, rather than 16 nuts and bolts.
Readily accessible equipment can be easily and quickly exposed for inspection and cleaning without the use of tools (see photos at top right).
Can the cosmetic covers in the bottom picture be designed to lift off rather than be secured with Allen screws or bolts as long as there are no OSHA concerns?
In every food plant the areas where the food product contacts a surface or where it may be exposed to the environment are crucial. Careful consideration is necessary to avoid food safety concerns in these areas. When designing equipment, concerns with the direct product contact surface are easy to recognize, but it is important to also recognize and consider the indirect product contact surfaces and even non-product contact surfaces as risk areas. These include areas directly above or below exposed product where the product may have some incidental contact or where defects in the design and construction could create food safety issues.
More sensitive products need more attention to the equipment details. The arrangement of structural components to avoid product collection points that would be difficult to clean, as well as finishes on welds, and eliminating openings into hollow frame construction, are all critical considerations. Determine if these areas will collect product that will support microbiological, allergen, pest or other contamination issues. How challenging will the equipment be to clean and how well will equipment materials withstand cleaning processes? Avoiding potential contamination issues is difficult unless research and communication between the equipment designer, fabricator and end user become critical.
I once had the opportunity to be part of a group asked to locate a source of metal contamination. On the surface, it did not seem possible that it was occurring in the system since the metal fragments were aluminum, and the system was fabricated from stainless steel (or so we were told). When we disassembled the suspected section of the system, we found that a small aluminum roller had been installed to compress the product as a process step. The roller was flaking due to daily exposure to the chlorine solution used to sanitize the equipment. A review of the design specifications showed that the equipment had been designed in this manner as a means to reduce costs. But, did anyone bother to inform the equipment designer that an aggressive chemical was going to be used on the system? Perhaps if they had known, the roller would have been made of stainless steel from the beginning, thus saving the company from destroying so much of their product.
Many times, food safety issues associated with facility or equipment flaws could have been avoided with proper research and communication. Forming a group of personnel with a vested interest in the project to oversee the design, installation and start-up can help prevent many of the issues that are realized after the project has already been completed. Do your research and keep asking the whys and what ifs. AIB
The author is Head of Food Safety Education, AIB International.