Remember that while U.S. food-regulatory agencies don’t directly regulate food equipment, they regulate its use to require cleanliness. As part of FSMA, the Preventive Controls for Human Foods Rule demands that all plants registered with the FDA prepare and implement written food-safety plans — or FSPs for short. These FSPs must identify and outline solutions for mitigating risks for each product. Designers will need to identify potential risks — including all chemical, microbiological, and physical issues that could arise. They will need to determine which of these risks necessitate preventive controls. Then they’ll need to develop preventive measures to mitigate the top risks; establish a monitoring program documenting how exactly risks are being mitigated; list any corrective actions; and continually verify the systems in place work. The new FSMA rule also demands that facilities reanalyze the FSPs at least every three years — or upon every significant design change.
Equipment and facility design is most effective in reducing contaminant risk when completed as a collaboration between OEM machine builders and food manufacturers. Until recently, Thomas Imholte’s Food Safety book was the sole reference for hygienic machine design. Now there’s an array of organizations we’ve already mentioned — as well as an OEM-led effort in partnership with food manufacturers to collaborate on what’s acceptable equipment design. This is called One Voice. It is a partnership that’s spurred a risk-based framework to define hygienic specifications.
Of course, hygienic design is non-negotiable, but there are other design objectives at play. So for example, one common goal of facilities is to ensure every square inch of installed equipment takes the smallest footprint — but is able to be cleaned daily to an allergen-free and microbiological level. There’s also the common design objective of keeping costs down. In fact, plant managers are finding that with the right machine builds — that are increasingly reliant on components specifically meant for washdown — that target of cost savings is satisfied. So it’s no wonder then that sanitary equipment design is going beyond what’s “high-risk food” handling such as lunchmeats and salads to adoption by other food producers — including those that sell dry goods … as well as microbreweries and niche industries that serve regional consumer bases.
Governmental and industry standards can often be informed by laboratory studies conducted by educational groups. Consider washdown-feature effectiveness studies conducted by the Virginia Tech Department of Food Science and Technology. Their main laboratory stretches thousands of square feet and includes myriad donated machines on which researchers study ways to process and package poultry, baked goods, vegetables, and dry staples. Corporate partner Tyson Foods works with the researchers on better packaging for Ball Park meat products. Motion-component suppliers have donated to the lab and brought food and beverage companies for discussions on the latest in hygienic design and sanitation. Also at the facility is a miniature beer-brewing facility to serve the growing craft-beer industry.
Some states demand adherence to 3-A Sanitary Standards Inc. (3-A SSI) standards. Elsewhere, some manufacturers participate in voluntary certification programs that allow for bragging rights and association-level branding and endorsements should equipment or setups meet guidelines. Within the U.S., governmental agencies certify equipment for sanitary machine design and fabrication. Some standard equipment for poultry, meat, or dairy, for precertification for certain tasks or operations — before it’s even installed.
In contrast, international trade associations such as the International Dairy Federation and the International Organization for Standardization (ISO) only focus on equipment review. In fact, there is also the European Hygienic Engineering and Design Group — the EHEDG. Much like how different states in the U.S. operate under standards that are mostly but not fully harmonized, so it is in the EU. There, the EHEDG is a consortium of equipment manufacturers, research institutes, food industries, and international health authorities that promote harmonization — mostly for the support of easier cross-border trade of safe food product.
Intersections with the National Sanitation Foundation (NSF)
In the U.S., the National Sanitation Foundation (NSF) offers guidelines that are associated with specific types of equipment. Their standards are harmonized with ANSI standards. For example, the NSF/ANSI 2 Food Equipment standards detail food-protection requirements for processing equipment such as bakery, cafeteria, kitchen and pantry units and end-user kitchen equipment. The NSF/ANSI 4 standards establishes sanitary designs for ranges, ovens, fryers, kettles, and re-thermalization equipment. There are other NSF standards that define what constitutes good machine designs for supply boilers, dispensing freezers, ice-making equipment, commercial bulk milk-dispensing equipment, and more.
Note that the NSF, 3-A SSI, and UL issue official standards. In contrast, trade associations generally issue guidelines to meet such standards. Case in point: The Consumer Brands Association (formerly the Grocery Manufacturers Association) publishes peer-reviewed articles and science-backed food-safety manuals. Some of their best libraries are those on preventing foodborne illness, thanks to in-house chemistry and microbiology expertise in processing and packaging methodologies. The CBA also touts expertise in machine, conveyor, and plant design for allergen containment and management.
Certain advisory boards for food and beverage aim to leverage the strengths of collaborative ventures with educational organizations to drive improvements in equipment features. Through such programs, food-science researchers can confirm which industry guidelines improves sanitation effectiveness. The research results are interesting to any company focused on reducing contamination risk and costs associated with efficient sanitization of equipment.
How standards affect food-manufacturing machine design
Now let’s explore the significance of FDA standards and other food-safety rules governing industry for machine builders. Consumers want safe and healthy food — in what they buy at grocery stores, markets, and restaurants. In the U.S., federal guidelines focus on the normal segments of our food supply chain. That means separate guidelines for farms, processing facilities, packaging plants, and distribution. Most FDA guidelines focus on the prevention of food adulteration or contamination. To be clear, equipment that doesn’t meet hygienic design principles (as well as equipment that’s improperly installed) can’t be sanitized well enough to prevent this adulteration of product with pathogens. Suboptimal setups can also be those that are cleanable, but just take longer to clean — or require more water and cleaning agent than better-designed systems.
What specifically do these standards require? In other words, what features render a motion or other machinery component or assembly sanitary and hygienic? Besides the FDA, trade associations provide excellent top-level guidelines on this. Consider the North American Meat Institute (NAMI) and some of what they’ve published on sanitary machine design. This used to be the Meat Packers Association … founded in 1906 Chicago and representing processors of beef, pork, lamb, veal, and turkey. It’s no coincidence that this time and place is the setting of Sinclair’s The Jungle.
First of all, machine sections should be accessible and open for inspection, maintenance, and sanitation. More open machine designs are less likely to trap foods and nasty debris. Unfortunately, many legacy machine designs for food and beverage manufacture employ unprotected or semi-protected servomotors and then add special protective enclosures that essentially turn whole sections of the assembly into areas that can trap moisture and more — which violates the principle of open design. But NAMI and the European Hygienic Engineering Design Group (EHEDG) have published hygienic machine-design guidelines that are quite clear on this point. Machines used in food and beverage manufacture should:
- Be cleanable to a microbiological level
- Be made of compatible materials
- Allow access for inspection, maintenance, and cleaning/sanitation
- Allow no liquid collection
- Hermetically seal hollow areas
- Have no niches
- Feature hygienic maintenance enclosures
- Feature documentation of validated cleaning and sanitizing protocols
- Allow hygienic connections and compatibility with other systems
Consider the last requirement for hygienic connections in the context of pneumatics. Many pneumatic cylinders on food and beverage-processing machinery have standard metric geometries. That’s in part because dimensions standardized on metric are preferred on machines destined for international distribution. Perhaps more importantly though, G-thread fittings (also called gas thread, British standard parallel pipe, or BSPP fittings) have parallel threads that seal flush to gaskets so there aren’t exposed sections of ribbed connectors. Paired with metric-sized pneumatic tubing having the same parallel threads, such G-thread fittings are maximally reliable. In contrast, NPT (National Pipe Taper) fittings having English-unit geometries can foster both microbial growth and contamination of foodstuffs with metal flakes and bits of PTFE tape. That’s because NPT fittings wedge taped threads together to achieve sealed connections … but threads and tape sections can remain exposed (and therefore, vulnerable to breakdown as well as debris accumulation).
To satisfy NAMI principles, linear-motion systems and electric motors in particular must have few or no external screws; specially engineered shaft seals; and gasket joints instead of metal-to-metal joints between assembly sections. Testing confirms that motion components violating these design principles will have bacteria present post-wash on all junctures except seal surfaces against which linear rails or motor output shafts move.
The smallest component elements are often where trouble brews. Rough finishes, stickers, stamped and etched labels, and nameplates on components (even if coated with a smooth finish) can quickly become areas of bacterial and viral growth. More suitable components feature surface finishes to less than a micrometer and annealed labels. In fact, NAMI Principle 6.1 recommends that product-contacting surfaces textures shall not exceed 32 μ-in. (0.81 μm).
Machines must also run without contaminating food with industrial substances or oils. Here, some materials (especially for seals and bearings) shield food while preventing bacterial growth.
On a similar note, food-compatible materials are key to preventing chemical interactions with consumable goods … especially acidic foods. Stainless steel is one option here, though epoxy-coated motion components withstand water exposure as well as caustic chemicals of washdown settings.
Machine designs should also avoid product or liquid collection, so there should be no indentations or crevices on the assembly. In addition, exposed areas of the machine should have rounded edges to prevent liquids from pooling. Any enclosed sections of the machine should accommodate the way the machine will most likely undergo temperature fluctuations — which cause atmospheric condensate to form on all machine surfaces upon cooling. Here, rounded surfaces designed to shed water can drain this condensate away most effectively.
Where sealing machine sections is the only option
Any inevitable hollow areas of a machine design should be hermetically sealed — though again, it holds that designers should avoid hollow frames and subcomponents wherever possible. Facilities should also validate cleaning and sanitizing protocols — and document processes for existing and new plant personnel. So explicit instructions for the use of cleaning chemicals (and which machine surfaces get treatment with which chemical) are essential. For example, some full-washdown-ready horizontal form fill seal (HFFS) machines for packaging fresh meat are rated to IP65 — even sealing elements — and isolate the electrical cabinet from the main machine frame. Surfaces are often smooth and angled to shed water.
It’s assumed that the flooring in any facilities housing these pieces of equipment is chemical and wear resistant. There’s more from the Meat Institute on this, and their reference gives the most specifics — so visit meatinstitute.org for that. Additional notes: Machine designs should be cleanable to a microbiological level. Lastly, ensure that personnel can get to all parts of the machine. As we’ll explore in more detail, again — it’s worthwhile to consider use of IP69K-rated subcomponents overprotective housings if possible.
Additional industry resources
The International Dairy Federation
3-A Sanitary Standards Inc.
North American Meat Institute
EHEDG: Food safety, quality, productivity, sustainability
NSF | The Public Health and Safety Organization
ISO 22000 — Food safety management
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Filed Under: Food + beverage, Packaging