PAG technology a new staple for food-grade lubricants

There have been significant advances in H-1 lubricant research and development over the years which have produced top performing products. The search for an even better performance by lubricant manufacturers continues, specifically in the food safety field and effects on the environment.


Since the original introduction of H-1/food grade lubricants into the food, beverage and pharmaceutical processing industries in the early 1960s, there have been significant advances in H-1 lubricant research and development which have produced top performing H-1 products. Polyalkylene Glycol (PAG) fluid technology is a shining example of these performance advances.

The original introduction of food grade lubricants into the food and beverage industry in the 1960s had two purposes: to provide protection for machinery, and to maintain food safety. In the beginning, food and beverage manufacturers were generally limited to using USP white oils having no additives. Functional lubricants were non-food grade conventional industrial lubricants.

Continuous improvements since the 1960s have led to today’s food grade lubricants which provide superior performance in hydraulic systems, gear and chains, compressors and many other standard applications.

Although the lubricant industry has achieved many successes, the search for even better performance by lubricant manufacturers continues. To food safety, there has now been added consideration of the impact of food grade lubricants on the environment. Most food plant managers have switched from non-food grade lubricants to advanced lubricants; however, there are still some who believe the performance or the cost of the advanced lubricants does not give them an edge over conventional industrial lubricants. But inevitably there are still occasions when a lubricant leak from machinery comes into contact with food being processed, resulting in fines or product recall.

A researcher seeking to develop a food grade lubricant to serve a specific purpose can select from base stocks and additives that have been approved by the Food and Drug Administration, as well as from a long list of substances in the Generally Recognized As Safe category. These are substances that have not been approved by the FDA, but that have been in long use as ingredients in foods and beverages.

Food grade lubricants are approved and registered by the National Sanitary Foundation, a non-for-profit organization. Before 1999, approval and registration had been in the hands of the USDA. The NSF registers lubricants according to the FDA-approved ingredients listed in 21 CFR 178.3570, “Lubricants with Incidental Food Contact or category H-1."

NSF toxicologists determine product acceptability based on FDA’s list of approved ingredients/raw materials against CFR 9, 21. NSF approval of a lubricant tells firms using the lubricants, as well as FDA inspectors, that the lubricants used conform with food safety requirements. The NSF’s online “White Book” lists all currently approved lubricants.

Three categories

The NSF places each non-food compound that it approves into one of these three categories:

H-1: Compounds and lubricants that are approved for use on a machine whose lubricated parts may potentially come in contact with food. Collectively known as “incidental food contact lubricants,” these are the lubricants that are approved for food and beverage manufacturing.

H-2: Compounds and lubricants that may be used on equipment that is sufficiently removed from food processing operations that there is no possibility of the lubricant or lubricated parts coming in contact with food. A remote compressor that provides air to food processing equipment is an example of the equipment that uses compounds and lubricants from this category.

H-3: Water-soluble lubricants often applied to equipment manufacturers to new equipment to avoid rust and corrosion during transport. These lubricants intended only for temporary application during transport, and are not acceptable for use in food processing plants and must be removed before the equipment enters production.

Within the Category H-1 food grade lubricants which comply with the FDA CFR 21, 178.3570 there are four types of approved lubricants. Plant managers can select from the following types of food grade lubricants:

  • White Mineral Oils
  • Natural Oils
  • Polyalphaolefins (PAO)
  • Polyalkylene Glycols (PAG)

The first two types are made using natural or non-synthetic base stocks. The latter two types are made from synthetic base stocks. Much of the progress in matching a food grade lubricant to the needs of an application have come from synthetic fluids, and of these the most significant are the PAGs.

PAGs are made from the reaction of alkylene oxide monomers to form polymers, which are composed of ethylene oxide and propylene oxide. Lubricants based on PAGs have been received favorably by food manufacturers because their performance exceeds the performance of lubricants whose base stock is a mineral oil.

A key reason for the superiority of PAGs is their ability to provide sufficient lubrication even in the presence of water. PAGs can be fine-tuned to achieve optimum performance. If the PAG polymers contains a higher percentage of ethylene oxide, then the base stock will have higher solubility in water; if the polymers contain a higher percentage of propylene oxide, the base stock will have lower solubility in water. Blending different PAG base stocks permits the production of lubricants that meet specific targets for viscosity and other properties.

Performance advantages

PAGs are also less harmful to equipment that has accidentally over-heated. Lubricants in the other three groups - white oils, natural oils, and PAOs - tend to leave a residue of carbon, gum or varnish. PAGs experiencing the same conditions leave practically no residue.

In addition, PAGs have excellent lubricity, low toxicity, and a high index of viscosity. They are biodegradable, have good cold flow behavior, and have good oxidative and thermal stability. Overall, PAGs represent a dramatic improvement of the base stocks that were being used in the 1970s.

PAG’s can be used to formulate food grade lubricants for applications such as compressors, hydraulic systems, gears and chains, and many other applications in food plants. Lubrication manufacturers use PAGs to develop lubricants specifically targeted for gear and chain applications for the food industry,

These are fully formulated, extreme pressure gear lubricants designed for use on worm and hypoid gears. They were developed with select ingredients identified in FDA regulation 21 CFR 178.3570 for use in situations where incidental food contact may occur. They have been registered with the NSF international under the H-1 classification.

PAG-based food grade gear lubricants provide high lubricity (i.e., a lower coefficient of friction), and have a high viscosity index that permits them to be used over a wide range of operating temperatures. When overheated to decomposition temperatures, these gear oils produce no sludge, varnish, gums or tars. Instead, PAG-based gear and chain oils, when they reach decomposition temperatures, convert to simple molecules and evaporate without leaving hard carbon deposits.

Because PAG’s inherently have lower coefficient of friction the gear box runs cooler. Most gear sumps tested were found to be cleaner compared to those lubricated by mineral oil based gear oils. Limited scale testing of energy consumption showed that these lubricants may enable a machine to use up to 8% less energy than an identical machine using petroleum-based industrial gear oils or food grade white oil based gear oils.

Lower energy requirements and superior thermal stability mean that these products will have longer life. In addition these lubricants biodegrade rapidly and have lower impact on the environment.

Longer Life with PAG - Typical Properties of PAG Gear Oils
Lubriplate PGO 100Lubriplate PGO 150Lubriplate PGO 220
Viscosity at 40°C102.4156.0221
Four-Ball Wear Test0.520.540.53
Weld Load Kg160160160
Load Wear Index32.933.433.4
FZG Wear Test, Pass Stage121212

A side-by-side field trial testing with the PAG gear oil and AGMA 5 petroleum based gear oil showed that the worm gear box unit ran about 15°F cooler on the new gear oil. At the same time, power consumption measured was about 7% less. Physical properties of the gear oil are shown in Chart 2.


High performance food grade PAG-based lubricants match or exceed the performance of conventional non-food industrial lubricants. PAG-based lubricants tolerate food chemical contaminations and water, and thereby increase the longevity of both the lubricant itself and the food processing machinery on which it is being used.

Sibtain Hamid is General Manager for the Toledo, OH operations and corporate technical director for LUBRIPLATE Lubricants Company. He can be contacted at (419) 697-4156 or by e-mail at shamid(at)

Also see Centralized systems can deliver proper lubrication

The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
Pipe fabrication and IIoT; 2017 Product of the Year finalists
The future of electrical safety; Four keys to RPM success; Picking the right weld fume option
A new approach to the Skills Gap; Community colleges may hold the key for manufacturing; 2017 Engineering Leaders Under 40
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Power system design for high-performance buildings; mitigating arc flash hazards
VFDs improving motion control applications; Powering automation and IIoT wirelessly; Connecting the dots
Natural gas engines; New applications for fuel cells; Large engines become more efficient; Extending boiler life

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me