Food grade solenoid valves and NSF/FDA regulatory approvalFood grade solenoid valves and NSF/FDA regulatory approval
June 1, 2001
All information and opinions presented in this paper are the authors. Design News online did no editing or confirmation of the information provided.
There are a number of government and private agencies involved in the regulation of "Food Grade" products, including federal agencies such as the Food & Drug Administration (FDA) and the United States Department Of Agriculture (USDA). Private agencies include the National Sanitation Foundation Testing Laboratory (NSF), Underwriters Laboratories (UL), and the 3-A Sanitary Standards Committees (International Association Of Milk, Food & Environmental Sanitarians, U.S. Public Health Service, and Dairy Industry Committee).
In the process of developing a component, such as a solenoid valve, for use in food and/or beverage equipment, a first level of approval is the NSF. In essence, the NSF has taken information released by the FDA...a White List of products "Generally Recognized As Safe" (GRAS) in contact with or consumed by the human body. The FDA produces this list and guidelines, but it does not regulate industries, including solenoid valves, in the way it does medical devices. In the case of solenoid valves, the NSF takes the FDA data and turns it into a set of categories for product evaluation.
The first stage of NSF approval is referred to as the C2 Standard. C2 refers to components that are used in food equipment such as soda fountains, beverage dispensers, ice makers, dinnerware, food carts...anything that contacts foods or beverages in a commercial setting. It is a local state agency such as your own Health Department that, before granting a license for a food service establishment, would look at the equipment to see if required NSF approvals have been given. For instance, a soda dispenser manufacturer, in the process of getting the whole machine approved, would choose components, such as the valves, that have met all of the requirements of NSF.
There are several categories for equipment approval. After C2, the second part of the approval is listing under Standard 61, which refers to drinking water system components. Basically, C2 approval allows valves to be used in any piece of food equipment such as icemakers, beverage dispensers, and dishwashers. But the C2 listing does not cover applications such as drinking fountains, faucets, and water meters. This is where Standard 61 comes into play. The reason is that NSF standards were developed following the FDA guidelines, while the standards in drinking water additives were developed around the EPA guidelines. This forces us to take the approvals in the C2 category and expand them to receive coverage in Standard 61, an NSF standard taking into account EPA requirements.
In developing a food and beverage grade solenoid valve, we must provide NSF with cross section drawings of all the components that would contact the media that flows through the valve, including the valve body, plunger, springs, insert materials, and the sleeve portion of the valve: The whole area
of the valve that the fluid travels through comes under evaluation in terms of whether the materials that the media contacts are, from a health point of view, considered hazardous or totally acceptable and generally recognized as safe. We must label each part of the valve and submit to NSF the exact material content of the valve body. Basically, the stainless steel components in the valve must be certified to contain a certain level of chromium, the material which prevents corrosion and gives stainless steel its stainless quality. Among other materials, we're not allowed to use copper in certain situations; on our AC valves, we use an aluminum shading ring which has no restrictions. In addition to that, certain grades of aluminum which are used in valve bodies are considered acceptable, and the type of finish that goes on the aluminum also comes under scrutiny by NSF. Many aluminum parts are anodized, requiring the provision to NSF of the anodizing method that was used to convince them that there are no residual surface coatings or anything that would be consumed by a person who drank a liquid which had passed through this valve.
Basically, all materials that could contact food come under review. On-the-spot audits by NSF can come unannounced: An inspector walking into a plant to see a food grade valve under assembly, opening up the valve, and asking for proof that all the components used are on the NSF accepted list and documented.
Another question involves the type of food that can come into contact with the valve and the temperature range in which it can be used. Sealing materials that are food grade approved are listed in categories including aqueous, acidic, dairy products, oil, beverages with less than 8% alcohol, and beverages with more than 8% alcohol. We use two seal materials: Fluorel and Santoprene are materials which have passed various extraction tests and meet FDA standards. NSF confirms that these materials meet the FDA standards. When evaluating for Standard 61, NSF also may do a type of extraction testing; they'll submerge the sealing material in various solvents for a certain period of time and, with some fairly sophisticated equipment, determine if the rubber or other sealing material dissolves into the liquid at all, and therefore, could become consumable. Since the sealing material ends up being one of the more challenging parts of the valve, it is logical to use off-the-shelf sealing materials that already have gone through extensive toxicology testing with various agencies and have a track record with the FDA and NSF.
When we meet all the criteria of NSF, we are allowed to apply the NSF mark (similar to a UL or CSA logo) which indicates the component and applicable standard, plus the food grade part number. NSF is concerned that we have a complete part number that gives a full explanation of all internal parts. Using the O-rings and flange seals that have already received approval under UL, we are able to say that many of the valves have UL and CSA approval, as well as the NSF mark and listing.
For further information, write: Food Grade Valves, Peter Paul Electronics Co., Inc., 480 John Downey Drive, P.O. Box 1180, New Britain, CT 06050-1180.
NSF approvals have been received by Peter Paul Electronics Co., Inc., New Britain, Connecticut, for the (left-to-right) Series 15, 20, 30, 50, and (pending) Series 70 solenoid valves. These NSF approvals allow nearly all Peter Paul valves to be used in food grade applications. Contact: Richard Ronzello (860) 229-4884
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