ENGINEERING SOLUTIONS / Post date: 10 December 2019
There can be some confusion about the uses of two very different types of lubricants… food-grade and biodegradable. Quite often, customers will ask for one when they really want the other.
It is always important to ask a customer about the application before making a recommendation about one of these two product types. Without getting too technical, this article will try to clarify these two types of lubricants and their intended uses.
Food-grade lubricants are those that are intended to be used in the food production business. Prior to 1998, the U.S. Department of Agriculture (USDA) was responsible for approving lubricants and ensuring compliance with certain standards, using a 3-tier system for food-grade lubricants, known as H1, H2, & H3. H1 was used where the possibility existed for incidental contact with food, H2 was used for where there was no possibility of food contact, and H3 was for use on hooks, trolleys, and similar equipment.
There is much more information about these three categories, but it is beyond the intent of this article. Please note that nothing in the description of any of the three categories has anything to do with biodegradation, which the American Heritage Dictionary defines as “Capable of being decomposed by biological agents, especially bacteria.”
Some food-grade lubricants may need to be safe for human consumption, but none need to meet any specific biodegradation performance. It is important to note that the USDA quit managing this program in 1998. Since then, the industry has worked to develop a replacement, with the National Sanitation Foundation (NSF) stepping up to succeed the USDA in developing new standards.
Biodegradable lubricants have been developed for a very different use… specifically applications where an accidental release could result in contamination of the environment… particularly where there is potential exposure to water. Biodegradable lubricants are designed to breakdown and degrade when exposed to the environment to prevent accumulation and damage to natural resources.
Biodegradable lubricants can be made from vegetable oils, synthetic esters, synthetic hydrocarbons, or “white oils.” At the risk of over-simplifying things, there are basically two different categories of biodegradable lubricants, those that are “readily biodegradable” and those that are “inherently biodegradable.”
Readily biodegradable lubricants are designed to degrade (decompose due to action of biological agents) more than 80% within 28 days. These are made from either vegetable oils or synthetic esters.
Inherently biodegradable means that the lubricant has the propensity to degrade over longer periods of time. This is somewhat more subjective, as all man-made materials will eventually decompose over time when exposed to the environment, and, as such, could be considered inherently biodegradable. However, inherently biodegradable lubricants are expected to degrade somewhere between 20% - 70% within 28 days. These products are typically made from either Polyalphaolefins (PAO) or highly processed mineral oils known as “white oils.”
The type of product that is best for your application will depend on many things and is beyond the scope of this article; however, it is an important decision that should not be taken lightly. Importantly, food-grade lubricants are not necessarily biodegradable and biodegradable lubricants are not necessarily fit for food-grade applications.
Castrol® has a team of experienced, field-based lubrication engineers that can help you to identify the right product for each application, identify opportunities to improve your maintenance practices, and help you to reduce your operational costs. Please contact your Castrol sales representative for assistance.