Food-Grade Lubricants

Food-grade lubricants and greases play a crucial role in the food processing industry, ensuring the safety and efficiency of machinery and equipment involved in the production of food and beverages. These specialized lubricants are designed to meet strict regulatory standards and provide performance characteristics suitable for use in environments where incidental contact with food is possible. In this article, we’ll explore the importance of food-grade lubricants, their composition and types, regulations governing their use, and their applications in the food processing industry.

Importance of Food-Grade Lubricants

The use of lubricants in the food industry as in any industry is essential for maintaining the functionality of machinery, reducing friction, and preventing wear and tear on equipment. Lubrication is most commonly needed for moving parts where metal moves against metal. Main uses are on plain and rolling element bearings, pistons,gears and for couplings such as conveyoring. However, standard industrial lubricants contain ingredients that are not usually safe for human consumption. Food-grade lubricants address this concern by meeting specific criteria that ensure they are safe for incidental contact with food during the manufacturing process.

The potential risks associated with using non-food-grade lubricants include contamination of the final product, compromise of various food safety standards, and negative impacts on the taste and quality of the food. Food-grade lubricants help mitigate these risks, providing a reliable solution for the unique challenges faced by the food processing industry.

Composition of Food-Grade Lubricants

Food-grade lubricants are formulated with ingredients that comply with regulations set by agencies such as the United States Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA). These lubricants often contain base oils, thickening agents, and additives that are carefully selected to meet specific performance requirements while adhering to food safety standards.

Common base oils or base stocks as they are also known, are used in all types of lubricants. They make up between 70 and 95% of the lubricant’s composition. Base oils are not found in nature but produced from crude oil. Roughly, 2% of all crude oil is turned into lubricant.

All oil fractions are generated by distillation. Base oil is the fraction taken off between diesel and heavy gas oil. However, unlike other distillate fractions, only the base oils go through a second distillation process but under vacuum. The distillates produced are further segmented into two main groups according to their treatment.

Mineral Oils

The most common base oil in fluid film and grease lubrication is mineral oil. It is regarded as the best material for lubrication of all machine elements. The cost is relatively low, it’s abundant and comes in a range of viscosities. The viscosity characteristics of mineral oil hydrocarbons is determined to a great extent by their molecular weight, molecular length and degree of molecular branching.

The mineral oils exist in liquid form over a considerable temperature range and pressure offering good film properties. They are hydrolytically stable with good oxidation stability at temperatures below 100ºC. Being hydrophobic, they repel water extremely well and are noted for  protecting metal parts containing iron from rust and corrosion. They work well with a good range of grease thickeners and additives.

The hydrocarbons used in mineral oils for lubrication contain hydrocarbons of over 25 carbon atoms or more. These molecules are over 25nm long.

The mineral oils being produced by distillation of petroleum crude oil are sourced from three categories;

• paraffinic – the most commonly used and mainly composed of alkanes
• napthenic
• aromatic

The classification of base oils comes from the American Petroleum Institute (API). There are five groups.

The mineral base oils (Group I and II) are base oils refined from crude oil. The synthetic base oils (Group III) are mineral base oils that are further refined through hydrocracking. The Group IV and V oils are generated by synthetic or chemical processes. The term hydrocracking comes from cracking heavy, high-sulphur molecule oils into better quality, low-sulphur molecules under high temperature and pressure

Synthetic Base Oils

The synthetic base oils are produced by particular chemical processes where they perform better because of a more consistent molecular structure and higher purity. Low molecular weight raw materials are reacted and combined together to produce the base oils of defined an desired lubricating properties. The main source is mineral oil from crude petroleum. Other sources include fatty acids for synthetic esters coming from seed oils and animal fats such as lard and dripping.

The synthetic oils are more expensive than base mineral oils but they come with additional performance benefits especially in particular situations where processing equipment for high-value products is used.

The common synthetic base oils include derivatives then of mineral oils, synthetic hydrocarbons, organic esters, perfluoropolyethers (PEPE), silicones and polyalphaolefins. These oils are chosen for their stability, resistance to oxidation, and compatibility with seals and materials commonly found in food processing equipment. Thickening agents are added, such as calcium or aluminum soaps, to give the lubricant a semi-solid or solid consistency, allowing for better adherence to machine surfaces.

The synthetics have a broader temperature range for operation and are better than naturally derived mineral oils. They also have a lower evaporation rate, higher viscosity index, good if not better performance at cold temperature and enhanced resistance to high temperature oxidation.

Additives play a crucial role in enhancing the performance of food-grade lubricants. Antioxidants, anti-wear agents, and corrosion inhibitors are among the additives used to improve the lubricant’s stability, protect machinery, and extend the service life of equipment. 

Soap Greases

Greases are thickened using additives but also by partial neutralization reactions of acid and base to produce a salt and water as a by-product. Calcium salts are the most commonly added.

Aluminium Soap Greases

These greases are extremely sensitive to shear and lose their consistency rapidly. They are not used for example in roller bearings and their maximum temperature is only 70ºC.

Calcium Complex Soap Greases

These are quite simple soaps. Calcium acetate is used as the modifying agent. They’re used over a reasonable range of temperatures and have similar performance to aluminium complex greases with dropping points over 250C.  They are used in plenty of roller bearing operations. These greases are increasingly developed with calcium sulphonate in mind. Calcium complex greases have a tendency to harden over time.

The calcium sulphonate complex greases have excellent water resistance, good high-temperature performance with good load-bearing capacity. One issue though, they do not perform as effectively as other foodgrade greases at typical food processing temperatures.  

Complex Greases

Greases can have highly sophisticated and complex compositions so that the correct type of application is made Calcium sulphonate (sulfonate) grease is often used for roller bearing lubrication where there is a high risk of water ingress.

The calcium overbased sulphonates as they are often called are common detergents in engine oils. They are dispersions in oil of amorphous calcium carbonate with a size of 1.5 to 10 nm. These oils are stabilised by a surfactant such as alkyl benzene sulphonic acid. When producing the grease, the amorphous carbonate is converted to crystalline carbonate which is mostly calcite. These calcium sulphonate greases have grown in size. They have the desirable characteristics of a high dropping point with good durability especially to extreme pressure and antiwear. Their downside is the complexity of their manufacture, high thickener concentration and high cost.

To overcome these limitations, complex calcium sulphonate greases were created where  anhydrous calcium 12-hydroxystearate was used as a complexing agent (Muir & Blokhuis, 1985). The water spray-off performance then it made it feasible to reduce the thickener concentration.

One of the weak points of calcium sulphonate grease is its low-temperature performance (i.e. a low drop melting point) hence the preference for lithium complex grease. The reason is due to a higher thickener content. The CaS greases are in fact gels and so do not separate into oil and other solids (Fish & Ward, 2012). The high thickener concentration also reduces pumpability (Madius & Smets, 2013). Although they have shortcomings the CaS complex greases are used in a variety of applications because they have such good properties in industrial situations (Macwood & Muir, 1999). They are used where water resistance is needed. They are then preferred to aluminium and lithium complexes.

In the case of the four-ball weld test, a weld of 315 kg, 400 kg or even higher is common with a calcium sulphonate grease. Calcite particles have been described as forming a wafer- or scale-like structure which creates shear planes that trap between the metal surfaces. This forms a sacrificial layer on the metal that is constantly sheared away. After all, it is better to shear the calcite particles than the metal on the equipment. .

CaS grease performs well in the presence of water and also has excellent temperature performance over 150ºC. They have a higher density than water so can be used underwater too.

The Nevastane (TotalEnergy) XS range, and XM 100 and 460 products are calcium sulphonate complex thickener based. The XS range are synthetic oils. Likewise, the iKV Tribofood brand is a calcium sulphonate range of greases of high repute and used in the drinks processing industry.

Lithium Greases

Lithium greases were developed in the early 20th century and started to replace aluminium, sodium and calcium thickened greases. The first patents were in 1942. These too were produced from stearic acid derived from beef tallow. Lard fat has been replaced now with castor oil derivatives such as 12-hydroxy stearic acid.

The lithium greases are used as chassis and wheel-bearing greases in a wide range of industries. Lithium greases have exceptional mechanical stability, a high drop melting point with good water resistance properties, and high temperature performance up to 120C. The main issue with it is poor pumpability at low temperatures so it is not useful in refrigeration systems. Apparently, lithium soaps are so elastic they do not move or pump well in long pipes. 

Lithium grease is the most widely used grease on the market commanding 71% with 51% for straightforward simple lithium grease and 20% for lithium complex grease. Lithium greases are not often used now as a food grade grease (Wang et al., 2021).

Unfortunately, the price of lithium hydroxide and lithium carbonate used in the manufacture of lithium grease has increased immeasurably because of the expansion of the manufacture of electric cars, batteries for cell phones and power banks.

Aluminium Complex Greases

The greases that were based on aluminium thickeners were developed in conjunction with sodium greases when steam engines were all the rage. At that time aluminium stearate was ideal because of its high water tolerance and high temperature capability. Unfortunately, they are extremely sensitive to shear forces and broke down rapidly over time where they lost their lubrication power. Some simple aluminium stearate greases are used as chassis grease and low-shear plain bearings.

The aluminium complex thickened greases  can withstand extreme pressures, high temperatures and are usually multipurpose with adhesive properties. The dropping point is above 240ºC and their upper temperature limit is 150 to 180 C. They have excellent water resistance.  The high adhesiveness properties mean they are suitable for medium to high speed bearings, for roller and plain bearings and crimping machines.

Their pumpability is considered one of the best of all greases but at low thickener concentrations. Aluminium complex greases are increasingly adopted for lubrication systems especially where roller bearings are concerned.

The Nevastane XMF00, 0, 1 & 2 (TotalEnergies Lubricants) are food-grade and based on aluminium complexes.  Nevastane HD2T is a good multipurpose grease which is extremely tacky and works well when water presence is high. It is used in bottling machine operations. This particular one contains PTFE additives.

Fluorine Greases

Fluorine compounds are added for situations where machinery is operating at a high temperature and in corrosive environments. These would be ones where powerful acids, halogenated compounds, various oxidants etc. are being used. TotalEnergy’s Statermic NR is a good example of this type of grease.

Analysis of Lubricating Oils

Tribological behaviour is measured mot commonly using the Four-Ball Machine method according to ASTM D 4172. 

Regulatory Standards

The regulation of food-grade lubricants is stringent to ensure the safety of the final food products. In the United States, the FDA regulates food-grade lubricants under the Federal Food, Drug, and Cosmetic Act. Lubricant manufacturers must adhere to the guidelines outlined in Title 21 of the Code of Federal Regulations (CFR) to obtain food-grade status for their products. The source of reference for permitted food-grade lubricants and greases is the NSF which publishes all products with H1 (food contact clearance) on its website at www.nsfwhitebook.org .

Mineral oil is defined under the US Food and Drug administration as 21CFR178.3620. The list of permitted additives is given by 21CFR178.3570.

Similarly, in Europe, the EFSA sets regulations for food-contact materials, including lubricants. The European Union’s Framework Regulation (EC) No 1935/2004 establishes the general principles for the safety of materials and articles intended for contact with food. Food machinery must now meet 2006/42/EC requirements.

NSF International Certified Lubricants

Lubricants that bear the NSF H1 designation meet specific criteria for food safety and are suitable for incidental food contact. Consult the WhiteBook which lists all the permitted ones for use particularly in the USA but are considered suitable for use world-wide.

The H1 lubricants are tasteless, odorless, physiologically inert. According to the NSF they are suitable for “Incidental, technically unavoidable contact with a food product up to 10ppm.” They are used in all sorts of machinery from pumps and mixers to bottle handling. The use of NSF H1 registered lubricants allows from a HACCP perspective, the elimination of potential contamination. The permitted level of consumption is a few parts per million. 

H2 lubricants are food grade but not especially food safe. They are used in food and pharmaceutical plants where they do not come into contact with food etc. Typical applications will be forklift trucks. They cannot contain “Carcinogens, mutagens, teratogens, mineral acids or intentionally heavy metals such as antimony, arsenic, cadmium, lead, mercury or selenium.”

The H3 lubricants are additives that can be used in the formulation of food-grade products. These are often edible oils, especially vegetable oils. They must meet FDA 21 CFR 172.860 and 172.878 regulations. They have a GRAS status which means they are safe for human consumption and so exempt from the Federal Food, Drug, and Cosmetic Act (FFDCA) food additive tolerance requirements. Some 3H lubricants also have H1 certification too. They are often used to clean and prevent rust on equipment such as conveyor belts, trolleys, cookware and hooks. 

All food-based lubrication greases will be NSF H1 registered and ideally be in compliance with both kosher and halal requirements. There are disreputable suppliers however who mislabel lubricants and not all countries adhere to these rules. One of the main issues is circumventing costs particularly as some additives added as thickeners are extremely expensive. From an ISO perspective they must be ISO 21469/ISO 213469 certified to comply with hygienic production in a food environment.

The ISO 21469 Certification

ISO 21469:2006 is a voluntary product certification standard that is internationally recognized. It specifies hygiene requirements for the formulation, manufacture, use and handling of lubricants. What makes this certification special is that it does not only apply to lubricants that can come into incidental contact with products and packaging used in the food and beverage sector but also applies beyond food safety to other markets such as including pharmaceuticals, tobacco, cosmetics as well.

Compliance with these regulations involves rigorous testing and documentation by lubricant manufacturers. They must demonstrate that their products do not pose a risk to human health and are suitable for use in food processing applications.

Applications in the Food Processing Industry

Food-grade lubricants find applications in various areas of the food processing industry, including meat and poultry processing, dairy processing, baking, and beverage production. In meat and poultry processing, where machinery is frequently exposed to water and cleaning agents, water-resistant food-grade lubricants are crucial for preventing corrosion and maintaining equipment functionality.

It has to be expected that lubricants will come into contact with food. Specific lubricants are designed to protect ferrous surfaces especially stainless steel. Some oils are needed for spraying equipment too.

Klüberfood NH1 K 32 Anticorrosion lubricant is used in areas where there is frequent washing. Anticorrosion comes from protecting surfaces by repelling moisture. All these lubricants are applied by brushing or with a spray gun.

Lubricants in all industries are designed to deal with extreme pressure. They usually contain oxidation inhibiting ingredients to help maintain performance over time. The presence of PTFE improves load-bearing performance.

In baking, where there is a high risk of lubricant migration onto food surfaces, lubricants with low volatility and excellent adhesion properties are preferred. These lubricants ensure that even in the event of incidental contact, the impact on the quality and safety of the final product is minimal.

Dairy processing, with its unique challenges of high temperatures and frequent washdowns, requires food-grade lubricants that can withstand extreme conditions while maintaining their performance characteristics. In the beverage industry, where hygiene is paramount, lubricants are used to ensure the smooth operation of bottling and packaging equipment.

In meat processing plants many of the standard greases can be used but some suppliers specialise in this type of lubricant. Bettcher Industries  (Birmingham, Ohio, USA) produce a variety of greases and multipurpose spray lubricants. The sprayable lubricating oil is over 60% mineral oil.

It’s worth noting that a number of suppliers will not state the specific chemical identities, CAS numbers and exact percentages.

Permitted Food-Grade Materials

Petroleum-based lubricants – Mineral oils used in H1 food-grade lubricants are either technical white mineral or USP-type white mineral oils. A number of articles often state that no mineral oil is permitted but that is a misnomer given the type of mineral oils used in the pharmaceutical industry in particular. These oils are highly highly refined and are colorless, tasteless, odorless and non-staining. Technical white oils meet the regulations specified in 21 CFR 178.3620. USP mineral oils are the most highly refined of all white mineral oils.

Synthetic lubricants – Synthetic H1 lubricant base stocks are often polyalphaolefins (PAO). Compared to white mineral oils, they have significantly greater oxidation stability and greater range of operating temperatures. Another approved H1 synthetic base stock is polyalkylene glycols (PAG). These lubricants are more increasingly used in high-temperature applications.

Dimethylpolysiloxane (silicones) with a viscosity greater than 300 centistokes (cSt)7 is also permitted for H1 lubricants. Silicones have even higher thermal and oxidation stability than PAO and PAG base oils.

Increasingly food-grade calcium sulphonate complex greases have been developed and finding use in heavy duty applications. At the research level, nano-additive carbon nano onions have been used to check the tribology performance of the grease (Wang et al., 2021).

Several PAG (polyalkylene glycol) base fluids are listed as H-1 base fluid. The FDA regulations state there are roughly three families of PAGs that are used for formulating food-grade lubricants according to 21CFR178.3570. These include the following:

• polyproylene glycol mono-butyl ethers
• Random copolymers of ethylene oxide and propylene oxide initiated on butanol and in which the EO/PO ratio is 1:1
• random copolymers of ethylene oxide and propylene oxide that are diol initiated in which the EO/PO ratio is between 75%/25% and 25%/75% w/w.

Vegetable Oils

Due to increasing concern over the environment, a move away from petroleum based lubricants is well nigh (Randles, 1992). The market share for biodegradeable lubricating oils is steadily increasing.  Typical natural vegetable oils include high oleic acid rapeseed oils (canola oil), sunflower oils, soybean and castor oils (Asadauskas et al., 1996). Rapeseed (canola) has an oil content of 40 to 45%, sunflower seeds contain 40% oil and soybeans contain 20% oil. Most vegetable oils from these sources are converted to fatty acid methyl esters. Soybean oil is produced mainly in the USA.

Rapeseed oil and high-oleic acid sunflower oil, are thought to be the best candidates for substituting the conventional petrol-based lubricating oils, as well as synthetic esters.   

Studies on castor oil and coconut oil which are thickened with lithium soap are claimed to form stable and consistent performing greases. These were compared with lithium-based paraffin grease as the control/reference. castor based grease has a better tribological performance compared to the lithium-treated paraffin grease. A fatty-acid derived protective thin film with high shear strength helps in these studies (Rawat & Harsha, 2022).

A large number of H3 lubricants are described as edible oils of which many are vegetable oils. The vegetable oils are prone to chemical reaction but this has also been cited as a means of promoting their biodegradeability. They must also meet FDA 21 CFR 172.860 and 172.878 regulations.

Rapeseed oil lubricant shows poor wear resistance because of the low strength of lubricating film. This resulted in poor metal-to-metal contact and adhesive wear (Arnsek & Vizintin, 2000).

Silicone Oils

Dow and iKV Tribology are major suppliers of silicone fluids which are used from lubrication through to defoaming (antifoams). A number of Chinese producers such as Hubei Zhuo Xuanyang (China) produce a variety of silicones for all sorts of applications.

The iKV silicone oil (Tribofood MHL 300®) has high natural viscosity, resistance to very high temperatures with good water resistance. These are used for lubricating bearings and hinges, as chain oil, for rollers on conveyors and as a fluid damper. The temperature range of -50 to 180°C.

Conveyor System Oils

Conveyor systems use chain oils or grease NLGI 2. They must be highly water resistant. Typical food grade and H1 compliant oils include Cassida Chain Oil 150, Cassida HF100 and Cassida EPS 2. In some cases where the conveyor is used in a frying processing line, then the oil from the fryer provides the lubrication. The EPS 2 grease is a synthetic extreme pressure grease. You find generally that mineral-based chain oil is not a permitted food-grade lubricant.

Roller Bearings

A typical oil would be a grease NLGI 2 but not a chain oil. A typical example to use would be Cassida EPS 2.

Gear Box

Specific oils to use would be gear oil. An example of a food grease option would be Cassida GL 220 or GL 460 which is used for worm gears.

Hydraulic systems

Normally, a specific hydraulic oil is used such as Cassida HF 68 and FM Hydraulic Oil 32 (Fuchs). All oils used must be certified NSF H1, NSF ISO 21469, DIN 51524 HLP and ISO 6743-4 L-HM).

Heat Transfer Systems

A specific heat transfer oil is used such as FM HT 32 (Fuchs).

Cutting Boards, Countertops & Butcher Blocks

Food-grade mineral oils are used to protect wood when used in meat and seafood processing facilities. It protects wood from bacterial contamination too.

Can Seamer Oil

Can seamer oils are specifically for use in oil-lubricated can seamers. They are formulated with USP white oil base stocks. Teresstic FG 150 (Mobil)uses unique additives which provides anti-wear properties with exceptional rust protection even in the presence of syrups and juices. It helps emulsify sugars and dry abrasives so preventing them from plating out on critical components. It is also used as a bearing and lightly loaded gear lubricant. Another brand to consider is Activate’s Foodcare CS150 with a temperature range of – 20°C to +150°C.

Refrigeration Oils

All equipment used in cold rooms will need a particular oil and grease suited to those temperatures. Roller bearings will use a grease NLGI 2 and good examples include Cassida EPS 00 or LTS 1. A chain conveyor will need a low temperature chain oil such as Cassida Chain Oil LT.

Synthetic refrigeration lubricants  such as Zero-Pol S are formulated with polyalphaolefin (PAO) base stocks. It comes in two viscosity grades 68 and 220. Such oils have excellent thermal stability and extremely low pour points for use in refrigeration compressors in severe industrial service.

Gear oil will be of any particular specification is used in these environments.

Sugar Dissolving Oil

Sounds an oddity but some specialist oils are used for dissolving sugar which accumulates on equipment in production and packaging areas. They not only dissolve accumulated sugar on machine parts but also remove dirt. Ideal for reducing maintenance costs and minimising shutdowns. Nevastane SDO (TotalEnergies®) and Activate Foodcare Sugarsolve are oils designed for this type of operation. 

Greases

These include FOODREX FG1 food-grade industrial greases are formulated with an aluminium-complex thickener and USP white oil basestock. This is white in colour and has a smooth-tacky appearance and contains an extreme-presssure additive for carrying heavy loads. An alternative is CAREM 330 grease which is formulated with a calcium-complex thickener with a USP white oil basestock.

The Lubricants Available

There are a vast range of lubricants available from a number of global suppliers which are listed as H1 and thus suitable for minimal food contact. We’ve listed a few of the major ones here.

1. Klüber Lubrication (Munich, Germany. A world leader in lubrication in a number of industries including the food industry.
   • Klüberfood NH1 Series – a range of synthetic hydraulic oils for both food and pharmaceutical industries. The series includes 32 and 46, 74-401. NH1 K 32 is an anticorrosion lubricant that is transparent and protects ferrous metal parts from rusting. It has a temperature range between 0 and 80ºC.
   • Klüberfood NH1 CH 2 Series
   • Klüber Summit HySyn FG Series
2. Mobil (ExxonMobil):
   • Mobil SHC Cibus Series – registered for NSF H1 requirements for incidental food contact which is a limitation of 10 ppm oil in a food product per FDA 21CFR 178.3570. These are not direct food contact lubricants.
   • Mobilgrease FM Series
   • Teresstic Series
3. Fuchs Lubricants:
   • Cassida Series – now have the Shell range.
   • Renolit Food2 Series. Five grades are available and formulated to contain anti-rust additives to protect against corrosion as well as containing extreme pressure additives.
4. Shell:
   • Shell Cassida Series – approved by NSF International as Class H1, AQIS Lubricant Type A compliant, USDA H1 requirements. Now moved to Fuchs.
   • Shell Gadus S2 V100 Series
5. TotalEnergies Lubricants:
   • Total Nevastane Series – NSFH1-registered products, meet stringent ISO 21469 hygiene certification criteria. Offer a full range synthetic products, PAO, PAG, Ester, outstanding performance calcium sulfonate complex and PTFE greases.
   • Total Food Grease Series.
6. Activate (Braintree, Essex. UK) – highly used in over 60% of applications in the food and drink industry. Foodcare 68 is an NSF H3 Process Aid oil which is Pharmacopoeia grade, white food safe lubricating oil. It is used for food contact surfaces such as dough dividers and baking trays. It has ISO 68 viscosity with a temperature range -5 to 50 ºC. The Foodcare 3H grease is used on protecting blades used in the meat and fish processing industry. It has great lubrication with low water washout potential. It operates over the temperature range -20°C to +120°C. Foodcare Pelletex 1 is used for pellet presses not grease points or bearings in feedmills. Also used for pet food contact surfaces. The Foodcare Longlife 000 is a fully synthetic semi-fluid grease for lubrication of automatic lubrication systems. It has a temperature range from -50 to 180ºC.
7. Petro-Canada:
   • Purity FG Series
8. Vickers Oil:
9. Bel-Ray:
   • Bel-Ray No-Tox HD Food Grade Grease

iKV Tribology (Raglan, Monmouth. UK) manufactures calcium sulphonate thickened greases with NSF H1 approval under the Tribofood™ brand name. These have excellent load bearing capacity with long lasting lubrication, anti-water performance and resistance to water washing and to sterilizing chemicals. 

Other suppliers include Pennine Lubricants (Sheffield, Yorkshire UK) who supply Foodtech Ultragrease Extreme. This too is a synthetic food grade lubricant for use in high water environments.

The Pharmaceutical Industry

All lubricants used in the pharmaceutical industry must have a particular quality. One specific case is the use of compression lubricants which prevent the adherence of granules and powders to equipment such as punch dies and faces. They are applied to ensure there is smooth ejection from the die after the tablet has been compacted. Lubricants are also applied to equipment to prevent powder and granule adherence to equipment surfaces and dosing kit.

The main minerals used in these examples are fats such as vegetable stearin, magnesium stearate or stearic acid. talc and silica. They are all hydrophobic and very effective at low concentrations.

Challenges and Advances

Despite the advancements in food-grade lubricant technology, challenges persist. Extreme operating conditions, such as high temperatures, heavy loads, and frequent washdowns, can still pose challenges to the longevity and performance of food-grade lubricants. To address these issues, ongoing research focuses on developing lubricants with improved stability, enhanced resistance to water washout, and better protection against wear and corrosion.

In recent years, there has also been a trend towards the development of bio-based food-grade lubricants. These lubricants, derived from renewable resources, offer environmental benefits and align with the industry’s growing emphasis on sustainability.

Conclusion

Food-grade lubricants and greases are indispensable in the food processing industry, where machinery reliability, food safety, and regulatory compliance are paramount. These specialized lubricants ensure the smooth and efficient operation of equipment while meeting stringent standards for human consumption safety. As the industry continues to evolve, lubricant manufacturers are expected to invest in research and development, leading to innovative solutions that address emerging challenges and contribute to the overall sustainability of food production processes.

References

Annual Book of ASTM Standards. (1995) Petroleum Products, Lubricants and Fossil Fuels, American Society for Testing and Materials, Philadelphia, 1995, Section 5, Vol. 05:1 ASTM D92, ASTM D97, ASTM D445, ASTM D2272, and ASTM D4172

Arnšek, A.; Vižintin, J. (2000) Lubricating properties of rapeseed-based oils. J. Synth. Lubr. 16, pp. 281–296. 

Asadauskas, S., J.M. Perez, and J.L. Duda. (1996) Oxidative Stability
and Antiwear Properties of High-Oleic Vegetable Oils. Lubri.
Eng. 52 pp. 877–882.

Bloch, H.P. (2009) Practical Lubrication for Industrial Facilities.

Fish, G., Ward, W. C., Jr. (2012), Calcium Sulfonate Greases Revisited.  NLGI Spokesman, 76(5), pp 1–20

Gebarin, S. The Basics of Food-Grade Lubricants. (Article). Accessed 19th January 2024.

Macwood, W., and Muir, R. (1999) Calcium Sulfonate Grease … One Decade Later. NLGI Spokesman, 63(5), pp 24–37. .

Madius, C., and Smets, W. (2013), Grease Fundamentals: Covering the Basis of Lubricating Grease, Axel Christiernsson: Kansas, US.

Muir, R., and Blokhuis, W. (1985) High Performance Calcium Borate Modified Overbased Calcium Sulfonate Complex Greases. U.S. Patent 4560489

Randles, S.J. (1992) Environmentally Considerate Ester Lubrication for the Automotive and Engineering Industries. J. Syn. Lubri. 9 pp. 145–161

Rawat, S. S., & Harsha, A. P. (2022). The lubrication effect of different vegetable oil-based greases on steel-steel tribo-pair. Biomass Conversion and Biorefinery, pp. 1-13

Wang, W., Qian, S., Gong, L., Ni, Z., & Ren, H. (2021). Effects of carbon nano onions on the tribological performance of food‐grade calcium sulfonate complex grease. Lubrication Science, 33(8), pp. 460-470