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Setting Limits for Food Grade Lubricants


Setting Limits for Food Grade Lubricants

How much is too much lubricant in food? Theres no simple answer, but food safety agencies, marketers and consumers would prefer none. While food grade lubricant manufacturers agree in theory, they are cautious about the practicalities.

Given the inevitability that foodstuffs will attract molecular hydrocarbons from all points on the food production chain, eradicating such molecules in the finished product may not be a realistic expectation. And in some cases, lubricant used in final processing machinery may not even be the culprit.

Ten in a Million

The U.S. government implemented constraints on lubricants used by food producers in the 1960s. It issued a regulation that specified the type and chemistry of acceptable lubricants and set safe limits on oil migration into food, codified in the U.S. Food and Drug Administrations 21CFR 178.3570. The U.S. Department of Agriculture devised the original alpha-numerical categories that have since become the standard designation system for lubricant manufacturers around the world.

The main category, H1 lubricants, are meant for use in processing equipment where they may accidentally come into contact with food. Twenty years ago, NSF International took over H1 registration that had previously been handled by the USDA, and all registered lubes are listed in the nonprofits online White Book.

H1 lubricants can be formulated with a variety of base oils, including highly refined mineral oil,polyalphaolefin, polyalkylene glycol andalkylated naphthalene, among others, as well as additives that meet FDA specifications. The limit for how much lubricant may inadvertently end up in a finished food product was and remains below10 parts per million-or the batch must be destroyed.

But this is where things get complicated. The 10 ppm limit can be misconstrued as a safe to consume limit. Many online sources on the classification of food grade lubricants present 10 ppm as a blanket limit for accidental food contamination with H1 lubricants and their additives. This is not necessarily the case.

Marianna Naum, policy analyst at the FDA, explained to LubesnGreases that 10 ppm was incorporated into the administrations regulations from information in a food additive petition submitted in the 1960s. The petitioner measured the amount of lubricant added to a food processing machine over a measured period of time, allowing for 100 percent migration of the test lubricant into the food.

The FDA evaluated this migration scenario as a worst-case situation, with the specification limit set to generously account for 100 percent migration, said Naum. The limit was based on use of mineral oil lubricants that would come into direct contact with food and is very conservative in that it represents a reasonable worst case for incidental lubricant contact. (Incidental means lubricant may contact food because of its use, although it is not intended to be added directly to food, the FDA clarified in a follow-up email.)

The FDA does not consider 10 ppm migration of any substance into food to be safe when the substance is used as a lubricant, she continued.Ten ppm migration is the default assumption that the FDA uses when determining exposure to lubricants.We then consider the available toxicity information on the substance to determine if the substance is safe at that level.

But if 10 ppm of incidental mineral oil contact with food is not safe, why isnt the limit set at zero? In order for that to be zero, if theres migration, that means there wouldnt useable lubricants, Naum said.

These days, food production plants implement what is known as a Hazard Analysis and Critical Control Points plan, which assesses and minimizes biological, chemical and physical risk in production processes. Also, improvements in machinery design mean lubricant migration is less likely, but it is still possible. Oil may still spin off from exposed conveyor belt gears, leak from ruptured hydraulic hoses or mix with released compressed air into the atmosphere.

Even so, the FDAs mandate is to protect public health with a reasonable certainty of no harm, so it makes sense that it errs on the side of caution. We feel that at these limits, there wouldnt be any adverse health effects, Naum said.

Toxic Target

Another reason that setting limits is an inexact science is the inability to pinpoint the actual toxicity of mineral oil lubricants. Toxicologists routinely struggle to determine absolute levels of safety that apply to every possible consumer in every situation, Tyler Housel, head of the Lexolube division for specialty chemicals company Zschimmer & Schwarz, wrote in a 2016 paper, The History and Future of Food Processing Lubricants. This, Housel argued, makes the direct calculation of an acceptable daily intake tricky because several unknown variables exist.

As Housel told LubesnGreases, proving whether or not something is harmful is difficult. If you feed something to an animal at a level until it dies, then you can subtract from that how much is safe to feed the animal, giving you an idea of toxicity in the short term. When youre talking about the concerns [over lubricants], youre talking about chronic illnesses such as cancer.There is no indication that these molecules cause long-term risks, but it is also impossible to say that its 100 percent safe without 30 years of testing, and none of us have time to wait that long, he explained.

When toxicologists talk about toxicity, they often refer to the direct consumption of a substance. In the case of direct consumption, if the limit is set at 10 ppm, a person weighing 100 kilograms could safely consume 1 gram of a substance. But were not talking about direct consumption, were talking about if the food contains 10 parts per million, Housel said. If you are eating chocolate bars that contain 10 parts per million but you are only consuming 20 or 30 grams [of chocolate], that is in the parts per trillion range, based on body weight.

The European Food Safety Authoritys guidelines go further than those in the U.S., distinguishing between the lubricants molecular weights. Larger molecules are less likely to accumulate in the lymph glands and liver. For example, a 100 centistoke oil has a maximum acceptable daily intake of 12 milligrams per kilo of body weight, whereas one with a viscosity of 68 centistokes has far less.

Origins of Molecules

If you have a machine and pump in 1 kilo of grease per 100 tons of food production, youre already at 10 ppm. But there are other areas in the equipment or in the factory, other sources of mineral oil hydrocarbons coming in, Andreas Adam, global sales director for German industrial lubricants company Fragol and chairman of the ELGI working group on food grade lubricants, told LubesnGreases.

Other sources of hydrocarbons in food are harder to pin down. They could just as easily be attributed to the exhaust fumes from farming machinery or the final products packaging materials as to leakage of lubricants in the final production process. Ingress can also occur from 3H products, which are meant for direct contact with food and include substances such as bread mold release sprays.

If you test broccoli grown near an airport youll find more mineral oil hydrocarbons than broccoli from a further field, because its covered in exhaust gases from the aircraft, Adam said.

We can measure [mineral oil hydrocarbons in the final food, but we cannot establish the origin of these molecules. They can be from nature, from contamination, from air pollution or, indeed, from lubricant. In some cases, they can have been put there on purpose as well, when 3H category products have been added to the food or food process, he said.

A major source of hydrocarbon molecules is packaging, Edward Janes, sales and marketing manager for Kluber Lubrication, pointed out during the ELGI food grade lubricants working group meeting in London in April. If you look at recycled paper board and do a swab test on it, you would never put it anywhere near food, he said.

This also raises questions about the realistic levels of hydrocarbons in food and places much of the burden of eliminating contamination on the end-producer facility.

Whether or not the source of a molecule can be precisely determined, suspect hydrocarbons are regarded in the same way by consumers and food safety advocates: They are bad. While these fears are not unfounded, and while certain substances in food are potentially harmful, they have resulted in demands from producers for lubrication products that are free of such molecules-something that Adam said is impossible, since many of them appear in nature anyway.

For example, coconut oil is a common product touted widely as a healthy foodstuff and cosmetic additive, such as in skin lotion and lip balm. It contains similar hydrocarbon molecules to lubricants, yet the perception of this product is that it is natural and need not be regulated to the same degree.

Although lubricants used in food production have been regulated for 50 years, it has only been in the past few years that they have formed as a problem in the public consciousness, especially in Europe. German food safety organization Foodwatch tested several chocolate and potato chip brands and found mineral oil aromatic hydrocarbons, thought to cause cancer.

The hydrocarbon industrys response was to urge German risk assessment agency BfR to issue a statement saying that MOAH posed no threat. But this only happened after Concawe, the European petroleum industrys environmental research group, provided decades of evidence, including ample testing on various types of molecules, to demonstrate that MOAH in highly refined base oils are not cause for concern.

End of the Production Line

Adam believes more education, especially of NGOs and legislators, is necessary to provide a clearer path toward a European standard. The combined industry, not only the lube producers but also the food producers, should work together in collecting the evidence and proof that products are clean and safe, he said.

Meanwhile, Housel feels that the onus will gradually shift toward original equipment manufacturers. The pressure will be less on the lubrication and more on the equipment, in other words, equipment that allows us to process food with minimal ingression of the lubricant into the food. And when I say minimal…much less than 10 ppm, if possible, he said.

Statutorily, wed like to get it lower, but I dont think they are interested in passing a law to make it lower, he continued. There is certainly a push with government in the United States right now to regulate less. I really dont see that we are going to get more regulation over the next couple of years.