Originally published at www.foodprocessing.com by Pam Demetrakakes, Senior Editor, Nov 03, 2020
When it comes to oil and grease, choosing among all the available options can be like trying to catch a greased pig.
Food contact-grade or not? Petroleum-based or synthetic? How much do you have to spend on lubricants to make sure there are no, so to speak, slip-ups?
Food-grade lubricants, collectively, are a class of lubricants that are highly refined and free of additives and impurities. Their use as lubricating agents in food plants is mandated under federal law, and practically no one in this country tries to get away with not using them at all. (It’s sometimes a problem overseas; earlier this year, Nestlé and other European food companies had to pressure Asian palm oil suppliers to stop using regular lube in their processing machinery.)
But there’s an important distinction among food-grade lubricants: whether they’re graded for incidental food contact. That means they’re recommended for use in equipment that contacts product directly, which includes most processing and packaging machinery.
Such lubricants bear an H1 classification from NSF International, a nonprofit agency that sets quality standards for a wide range of industries and products. Lubricants that are food-grade but not rated for incidental contact are classified H2; they’re intended for use in applications where there is virtually no possibility of food contact, such as bearing housings for conveyor driveshafts. (NSF has other “H” classifications, such as H3 for soluble oils for cleaning and rustproofing equipment like hooks and trolleys, and HT1 for heat transfer fluids.)
Just as food-grade lubricants are more highly refined than general-purpose ones, H1s are more highly refined than H2s. And just as food-grade lubricants are more expensive than general ones, H1 lubricants are more expensive than H2s; the average margin is 10% to 15%, according to Brandon Brownlee, an account representative for Motion Industries.
Performance issues
There is, or was, another point of difference. Food-grade lubricants in general don’t perform as well as non-food-grade ones, which is another reason that some overseas processors are tempted to use the latter. The extra refining needed to purify the lubricant’s petroleum base reduces its lubricity and heat resistance. That difference carries over to H1 and H2 lubricants – or it used to.
“Everybody that was in food processing, your maintenance guys, all felt that the [H1] food-grade lubricants were poorer lubricants. And that was very true – they were not as good a lubricant,” says Mike Montgomery, president, West Coast division, Huskey Specialty Lubricants. “And you had to pay more because the extra processing of the petroleum base oil cost more. So what you’re getting is not as good a product for more money.
A lot of plants are switching full-on to food-grade products because the quality of them is so much better now, and they can be used plant-wide -- Mike Montgomery, President, Huskey Specialty Lubricants
But that belief, which is still widely held, is outmoded, Montgomery and others say. The performance gap between H1 and H2 lubricants has narrowed to the point where there’s no reason to use H2 just on a performance basis alone.
“You could actually go into a plant in today’s world, and the trend has been there for at least the last 10 years, a lot of plants are switching full-on to food-grade products because the quality of them is so much better now, and they can be used plant-wide,” Montgomery says.
That leaves expense as the only reason to use H2 lubricants. But lubricant suppliers say it’s a false economy.
To use both H1 and H2 lubricants, plant managers have to set up a two-tiered system, with both kinds of lubricants rigidly segregated, and color-coding or other measures in place to prevent their misapplication. Even then, they’re pushing their luck; there’s still a high risk of an H2 lubricant being used where traces could get into product.
“The people out there lubing the equipment aren’t necessarily your top executives,” Montgomery says. “They’ll grab a grease gun or oil and they’ll put the wrong oil in it, and put it on the machine.”
If a lubricant is mistakenly applied and it can’t stand up to the application, there’s a risk of equipment failure. If the wrong lubricant can keep the equipment running but it’s H2 instead of H1, there’s a risk of contamination, which will become inevitable the longer the H2 lubricant is used.
The expense of cross-contamination of oils to machinery in conjunction with the possibility of not using an H1 product when called for far outweighs the added expense of H1 lubricants
“Even though it’s incidental, in certain food industries, there’s a really, really high possibility you’re going to get a little trace of that grease or oil in [the product],” Montgomery says. For that reason, many plants are avoiding H2-rated lubricants altogether.
“The expense of cross-contamination of oils to machinery in conjunction with the possibility of not using an H1 product when called for far outweighs the added expense of H1 lubricants,” Brownlee says.
“Many food plants are switching to 100% H1 products to reduce the number of SKUs and to prevent cross-contamination.”
In some cases, the use of H2 lubricants in H1 applications might be a matter of simple ignorance.
“There still remains significant confusion in the marketplace about the differences between H1 and H2,” says Jim Girard, executive vice president of Lubriplate.
Particularly in smaller or less-organized plants, maintenance workers might not even know about the distinction. Such workers may see “food-grade” on a label, perhaps accompanied by the NSF International logo, and conclude that it means the lubricant is safe to use anywhere.
“The maintenance guys look at that and say, ‘OK, it’s a food-grade grease, we can use it.’ Well, it’s not,” Montgomery says. He recounts a visit to a plant in Colorado where he saw black grease dripping off a food line. When he asked about it, he was told it was H1 grease. He pointed out that it probably wasn’t because of the color and asked to see the cartridge; sure enough, it wasn’t, but it had the NSF logo.
Real or synthetic?
Another decision facing lubricant buyers is whether to stick with petroleum-based lubricants or use synthetics. Synthetic plant equipment lubricants are somewhat analogous to synthetic motor oil: more expensive, but with better performance and longer life.
“Synthetic lubricants are much more oxidation-stable, meaning they excel at elevated application temperatures,” Girard says. “Also, synthetics significantly outperform petroleum-based lubricants in cold temperature applications.” Other advantages of synthetics are better demulsibility (water separation), longer drain intervals, improved film oil strength and better energy efficiency for the equipment it lubricates.
Some synthetics can lead to a dramatic increase in machinery performance, well justifying their extra expense, Montgomery says.
“We can go into a plant and I can tell a plant manager, ‘I can increase the life of the bearings on your machine by 50% if we switch over to a synthetic,’” he says.
Water resistance is another important advantage of synthetics. In some cases, the resistance is so good that lubrication between washdowns is no longer necessary. In addition, because synthetics experience less water separation, they contaminate the washdown water less than petroleum-based lubricants, leaving the water cleaner and easier to treat.
“The less contaminant they’re putting into their water collection system, the less they have to treat,” Montgomery says. “So they save money at both ends.”
The best bet for specifying lubricants is to simplify as much as possible. The ideal approach is to use H1 products everywhere on the plant floor, but in any case, the variety of lubricants, and their sources, should be streamlined.
“I have personally seen the evolution of lubrication in federally inspected meat plants for 36-plus years,” Brownlee says. “There is a trend to review all lubrication and to consolidate to define vendors and to review all applications. With this review and standardization, you see reduction in number of lubricants, increased drain intervals for oils and longer grease life. In most cases, a program is established to properly train the staff about proper lubrication and an identifier system for proper applications of lubrications.”