The challenges of food-grade lubricantsKen Thayer | November 19, 2018
Lubrication is essential for the proper operation of manufacturing and processing machinery. Food processing includes a variety of equipment such as mixers, conveyors, grinders, pumps, motors, ovens, and labeling and packaging machines. The handling of or direct contact with food creates some unique challenges for lubrication.
Cross-contamination is a major concern for any equipment used in the handling, packaging or processing of materials used in the food or beverage industry. This is true for other processing applications as well, but the risk to human health in food applications magnifies the implications of contamination. Lubrication is a necessity to keep bearings and other machine components operating smoothly, so what are the options for keeping equipment running and food products safe?
To address this important issue, the National Sanitation Foundation (NSF) has evaluated and registered the chemical compositions of various lubricants deemed safe for contact with food or raw materials that come in contact with food and grouped them into three different categories.
H1: Lubricants that are intended for applications where the potential for incidental or accidental contact with food exists under normal use conditions. This does not imply that the lubricant or grease is safe for direct food contact or that it is safe for consumption. Any contact must be limited to trace amounts, not to exceed 10 parts per million or 0.001%. Any contamination in excess of this amount renders the food unsafe for consumption. Most lubricants referred to as food-grade are H1 lubricants. The U.S. Food and Drug Administration lists the substances allowed for incidental food contact in Code of Federal Regulation (CFR) Title 21 Section 178.3570. Food-grade lubricants do not contain sulfur-phosphorous, commonly found in many industrial oils. Instead, they are usually made with base oils of polyalphaolefin (PAO), polyalkylene glycol (PAG) or white oils.
H2: Lubricants that are used in applications where there is no potential for contact with food. As there is virtually no risk of contamination, these lubricants carry fewer restrictions than H1 lubricants.
H3: Soluble or edible oils that are used to clean or prevent rust.
While the U.S. has established food-grade regulations, Europe and many other countries have not. If they adhere to any standards, most foreign lubrication formulators will defer to U.S. Title 21. Although Canada generally follows the U.S. Title 21 regulation, Health Canada does set standards and policies that are enforced by the Canadian Food Inspection Agency. The International Standards Organization (ISO) standard 21469, created in 2006, is a voluntary standard for the formulation of lubricants for food-related applications, as well as those used for animal feed, pharmaceutical and cosmetics.
Challenges of Food-Grade Lubricants
In addition to the obvious benefits to safety and human health, food-grade lubricants exhibit additional advantageous qualities. Like traditional lubricants, they prevent direct contact of moving elements, reducing friction and wear.
However, the limitations to the chemical composition of H1 lubricants to make them safe may adversely impact the performance of the components they lubricate, especially with regard to corrosion and wear resistance. Other requirements include the ability to dissolve sugars and remain neutral in contact with elastomers and plastics.
This is especially true in extreme conditions, such as extremely high or low temperatures, steam and washdown applications, common in the food processing industry. Other applications, such as can seaming, create high friction, wear and heat generation. These conditions are tough on any lubrication but present even more challenges for food-grade lubricants due to the limitations in chemical composition.
For these harsh conditions, a solid or dry film lubricant may be a practical selection. Solid and dry film lubricants create self-lubricating components and cannot be washed away. Products can be purchased or applied post-purchase. A newer dry lubricant solution is solid oil. Some bearing manufacturers, such as SKF, supply bearings with an H1-approved food-grade solid oil lubricant. For additional information, see “How to Select the Right Bearing Lubricant.”
The chemical requirements for food-grade lubricants are typically at odds with those for biodegradable or environmentally friendly lubrication products. Although H1 lubricants exhibiting these properties may exist, the requirements for food-grade lubricants does not address these concerns. However, new regulations are driving the future development of biodegradable and environmentally friendly food-grade lubricants.
Another issue concerning food-grade limitations involves adherence to religious prohibitions, specifically those related to kosher (Jewish faith) and halal (Muslim faith) foods. Restrictions go beyond food ingredients and extend to anything that may come in contact with the food, including incidental lubricant contact and the composition of those lubricants. This is not a trivial concern, considering there are approximately 15 million Jews and 1.8 billion Muslims worldwide.
Adherence to Regulations
According to a 2007 article by Machinery Lubrication, 60% of U.S. food and beverage corporations were not adhering to the food-grade lubrication regulations. The paper further described that even some of the remaining 40% may be using H2 lubricants in applications requiring H1 lubricants.
Several factors are responsible for these low adherence numbers.
- Poor education on food-grade lubrication regulations, including a lack of understanding about the difference between H1 and H2 lubricants.
- Performance limitations of H1 lubricants combined with increased production and equipment uptime requirements.
- Extreme operating conditions in some food processing applications.
Some processing equipment suppliers have begun manufacturing their own H1 lubricant, optimized for the specific operating conditions. Others are concentrating efforts on improving sealing and machine designs to decrease the potential for incidental lubricant contact with food.
Recent advancements include lubrication additives that help with wear, heat and corrosion protection. Companies such as Functional Products Inc. are producing additives to address these shortcomings and close the performance gap between H1 lubricants and industrial lubricants. These additives comply with Title 21 regulations and are compliant with Jewish and Muslim restrictions.
Although there are established regulations for the use of lubrication in food and beverage applications, a significant percentage of U.S. manufacturers do not adhere to them. International standards lag behind the U.S., with many countries relying on NSF’s CFR Title 21 Section 178.3570, if they follow any regulations at all.
Advancements in new lubrication technologies, such as solid oil, as well as lubrication additives are making the use of H1 lubricants viable without an adverse impact on performance or equipment uptime.