Food-grade lubricants must perform the same technical functions as any other lubricant: provide protection against wear, friction, corrosion and oxidation, dissipate heat and transfer power, be compatible with rubber and other sealing materials, as well as provide a sealing effect in some cases.
In addition, different applications within the food and drugs business demand that lubricants resist degradation from food products, chemicals and water/steam, must exhibit a neutral behavior toward plastics and elastomers, and have the ability to dissolve sugars. These oils must also comply with food/health and safety regulations, as well as be physiologically inert, tasteless, odorless and internationally approved.
Lubricants can be subjected to intense environmental contaminants. A corn-milling environment generates significant dust. Although not as hard as silica-based dust, it still presents a problem for filtration. A meat plant requires stringent steam cleaning at all times, so the risk of water contamination is high. Some plants experience as much as 15 percent by volume of water in their gear oils.
Another aspect of lubrication contamination that poses a risk to food-grade lubricants is the growth of microorganisms such as bacteria, yeast and fungi. While these can be a risk in industrial environments, the opportunity for contamination in the food-production environment is even greater.
The United States Department of Agriculture (USDA) created the original food-grade designations H1, H2 and H3. The approval of a new lubricant and its registration in one of these categories depends on the list of the ingredients.
- H1 lubricants are food-grade lubricants used in food-processing environments where there is the possibility of incidental food contact.
- H2 lubricants are food-grade lubricants used on equipment and machine parts in locations where there is no possibility of contact.
- H3 lubricants are food-grade lubricants, typically edible oils, used to prevent rust on hooks, trolleys and similar equipment.
Deciding whether there is a possibility of contact is tough, and many have erred on the side of safety with respect to selecting H1 over H2.
Approval and compliance were, in the past, the responsibility of the USDA. The agency is considered an internationally renowned authority on consumer safety issues with regard to the food-processing industry. Its efforts essentially covered federally inspected meat and poultry facilities but were rapidly adopted by other sectors such as fisheries and retail food operations.
To gain USDA approval, lubricant manufacturers had to prove that all the ingredients in the formulation were allowable substances. Allowable substances, in this instance, are those listed by the United States Food and Drug Administration - FDA in accordance with the Guidelines of Security Code of Federal Regulations (CFR) Title 21, 178.3570. This did not include lubricant testing; rather the approval was based primarily on a review of the formulation ingredients of the lubricant.
However, since September 30, 1998, the USDA has no longer been issuing registration of food-grade lubricants or reviewing federally inspected meat and poultry process facilities.
The author is an experienced pharmaceutical blogger.