The Down and Dirty:
Shelf Life of Grease
WHY GREASE GOES BAD AND HOW TO KEEP IT IN TOP SHAPE
One of the most popular questions about lubricating grease is its shelf life. How long does it really last? (Another common question is about grease color. Check out our last blog on grease components for a refresher on hue.)
Unlike food or consumer products, most grease is not marked with a “best by” or expiration date. Let’s be honest—grease is often sitting in a shed or toolbox for many years! Since grease and packaging are getting more expensive as technology advances, and supply is lower than demand, you want to take care of your purchase. Read on to learn what affects shelf life, why grease goes bad, and how to best store grease to extend shelf life.
What Makes Grease Go Bad?
There is no single answer on grease shelf life because there are many factors at play; plus, grease deteriorates naturally over time. As we described in our last blog, The Down and Dirty: Grease Components, a grease commonly includes three parts: a base fluid, thickeners, and additives. The ratios of these components are used to enhance textural, chemical, and protective properties, though some components also degrade or prolong the grease’s shelf life. Careful planning can help you avoid some factors. (Keep reading for our section on storage best practices below.)
When handling grease one must avoid dust and dirt, as well as water. Even small amounts of dust or moisture can severely deteriorate grease quality. Air (also referred to as atmosphere) can be a contaminant, too. Ill-fitting containers can allow in air that can corrupt the product. Pails, tubs, cartridges, and drum lids should be replaced with the same care you use with paint. Just like you would close paint carefully to keep it from drying out, you need to put the lid back on grease properly so it won’t go bad.
Light may impact color and appearance in lubricants. Grease and other lubricants tend to come in opaque metal or plastic containers to block light and keep the product in usable shape for longer.
Pack Logix uses packaging containers designed to protect grease for the long run.
How Can You Tell if a Grease Is Bad?
- Excessive oil separation (a little is normal)
- Consistency change
- Unnatural color or odor
- Change in texture
What Are Storage Best Practices?
Storing your grease correctly is one of the best ways to improve its shelf life—which also protects your investment and supports your equipment. We turned to our Pack Logix experts for tips to keep in mind:
- Store grease in the original container, tightly covered or closed, to avoid contamination. (Airflow in and out of a container creates moisture and can contaminate grease.) The packaging should not show any signs of damage like severe denting or corrosion.
- Maintain a dry, temperature-stable environment. Greases should be stored in a temperature range between 32° and 75° Fahrenheit.
- Pick an inside storage space over an outside one. Interior spaces provide more stability in terms of temperature and light.
- Choose a spot that is free of particulate contamination (dirt and dust). Avoiding airborne particles is especially important when storing a partially used container for later use.
- Wipe off the tops and edges of containers before opening to avoid contamination.
- Use clean tools and equipment when pumping or handling lubricants and greases.
- Rotate your inventory. Check the container fill date and use the oldest container first.
So How Long Does Grease Last?
Grease in an unopened container should last 3 to 5 years. For an opened container, the go-to answer is 1 to 3 years depending on the various factors listed above. If the grease has not been contaminated and hasn’t broken down too much, it should be perfectly fine to use for a couple years even if it doesn’t look as pretty as when it was purchased.
Now that you know how to check products for damage or contamination, how best to store grease, and how long grease should last, you will have a better sense of which greases in your inventory might be usable. For other questions about packaging grease properly to help preserve its shelf life and working life, please reach out to our experts. We look forward to helping you!