Developments in food-grade lubricants

Lubricants form a core part of almost all industrial processes. These chemicals keep a plant’s moving parts protected from wear and disperse heat build-up, among other vital maintenance functions.

Unsurprisingly, these lubricants play a key part in the more industrialised side of food processing, a side that allows the industry to supply a ravenous global market with plentiful food products of consistent high-quality.

Processing food isn’t the same as building a car or manufacturing electronics, however. Industrial machinery sits rather uncomfortably in a food production environment.

The hygiene standards required for food plants means the proximity and interaction between machinery and the end-product needs to be much more carefully managed.

Food-grade lubricants

Well-designed food plants should build strict sanitary standards into their day-to-day operations, but the risk of food coming into contact with unintended materials cannot be entirely eliminated. With standard industrial lubricants, the chemical compositions of which can be highly toxic, this poses a significant threat of contamination.

Food-grade lubricants were introduced to the food processing industry in the 1960s to maintain the integrity of machinery while safeguarding food safety. These lubricants have been separated into three categories by the United States Department of Agriculture: H1, H2 and H3.

H1 lubricants are used for machinery that could potentially come into contact with food products, which therefore must have the highest standards of non-toxicity. H2 lubricants are for use in locations that can be guaranteed to have no food contact, and H3 lubricants, usually composed of soluble oils, are used to clean and protect hooks, trolleys and other standard equipment.

As the lubricant category with the most safety-critical application, H1 lubricants are regulated by standards from organisations like the US Food and Drug Administration (FDA) and international health and safety certification group NSF. The four types of H1 lubricants that are approved for use by the FDA are split into synthetic and natural options.

White mineral oils and natural oils are made from natural base stocks, while polyalphaolefins (PAO) and polyalkylene glycols (PAG) are based on synthetic materials.

These options have their own advantages and disadvantages, and food processors must decide which to choose based on the suitability of their own operations. But across the board, the story of food-based lubricants has been one of continual, gradual refinement since their introduction – evolution rather than revolution.

Companies like SKF have been responding to the particular challenges of the food plant environment over the years, developing lubricants with greater corrosion resistance and water exclusion, as well as hygienic design.

Fabrication and accreditation: Modern advances

One of the most significant evolutions of food-grade lubricants has been the gradual development of a group of standards, both national and international.

The publication of an international certification for lubricants with incidental product contact, ISO 21469:2006, has helped clarify the specifications required for food-grade lubricants, allowing purchasers to make more informed decisions.

Securing this international certification is also seen as a significant commercial boon for manufacturers that manage to meet the requirements. In February 2011, UK-based food-grade lubricants manufacturer Rocol became the country’s first ISO 21469-certified producer of lubricants with its Foodlube lubricant range.

According to the company, this accreditation will provide food and beverage plants with peace of mind when offering their products to retailers and being subjected to the audit process from organisations like the European Food Safety Inspection Service (EFSIS), the British Retail Consortium (BRC) and major supermarket groups.

"We are committed to helping UK food and drink manufacturers achieve excellence in safe, food-grade manufacturing which is why we have invested in securing ISO 21469:2006 certification," said Rocol’s UK sales director Brendan Kendrick.

"It means complete audit trail peace of mind for manufacturers who benefit by being able to prove that the lubrication products used throughout their processes have been subjected to stringent and rigorous hygiene and safety testing."

In terms of lubricants themselves, manufacturers have been gradually improving performance to suit the tough operating environment found in food plants (intermittent operation and wet, humid conditions can wreak havoc on machinery), making their products more adaptive, better for the environment and more resistant to problems like oxidation.

A good example of this ongoing evolution is Petro-Canada’s Purity FG range of white oil-based food-grade lubricants. Over the 20 years of the product’s history, Petro-Canada has refined its formula and introduced new innovations to the line. For example, the company introduced Microl to many of its lubricants, an Environmental Protection Agency-registered antimicrobial preservative that protects lubricants from food-specific micro-organisms that can cause product degradation and odour.

All this development has led to Petro-Canada’s newest iteration of the Purity FG compressor fluid, a product the company believes is more resistant to heat, high air flow exposure and oxidation, with an improved anti-wear performance to protect components like rotor bearings within rotary screw compressor units.