Food lubricant Q&A: Dyes are useful, but use caution

The following questions were sent to Noria Corporation regarding food-safe lubricants. A Noria service professional provided the answers.

Question: “I want to add a colorant or dye to my food-safe lubricants to ensure that there are no errors in selecting the right product in the lubricant storeroom. Is this a good idea?”

Answer: While the regulations do not call for special precautionary measures such as this, any attempts to eliminate potential error are a good idea. I know some companies that have implemented separate storage areas for food-safe lubricants and handling equipment to address this same problem, or have switched all their machines to food-safe lubricants irrespective. However, a word of caution. In general, food-safe lubricants are, specifically colored by the supplier. If not, then discuss your request with your supplier. The concern with adding aftermarket colorants or dyes to the food-safe product is that there may be some chemical reactions which may produce toxic by-products in the lubricant. Therefore, if adding any dye, it should be retested or qualified for food safety.

Question: “My company uses a lot of food-grade oils and greases. Because the base oil in these lubricants is a white mineral oil, it is hard to see the level in the site glasses, especially when the oil is new. Our mechanics have asked, ‘Why can’t we add a food-grade coloring to the oil when we put it into the gearboxes and pumps so it’s easier to see?’ My food-grade lubricant supplier has told me that adding anything to the oil, even another food-grade substance, will adulterate the food-grade quality. Personally, I am afraid anything we add could cause other problems, such as foaming or inhibit some of the qualities in the oil. Is there something that can be added to make the oil more visible to the eye and not hurt the application?"

Answer: I agree with the statement from your oil supplier, and your concerns on additive damage. I would not recommend adding any dye, colorant or aftermarket additives to an oil without approval from your lubricant supplier. Many lubricant suppliers have a list of approved dyes in non-food-grade applications. Without their approval (in writing if possible), there clearly could be an impact on the legitimacy of the food-grade H1 rating. However, like most puzzles and challenges, we sometimes miss the obvious! Consider adding a bright red float in your oil sight glass to make oil levels obvious.