Lubricant suppliers do not recommend the use of lubricants beyond the stated shelf life. But for the average user, identifying an expired lubricant may not be as easy as it is with something such as food, where “best used by” dates are prominently displayed, and rotten food is obvious. Knowing more about what to look for regarding the shelf life of oil can help determine if it is good to use or should be recycled.
For most lubricants, the rule of thumb for shelf life is five years. But if the seal on the container is broken the five-year rule should be ignored and it takes an experienced lubrication expert to tell if something is fit for use. Most lubricant manufacturers recommend that in the case of a broken seal, assume the lubricant is past its shelf life.
There are, however, some easy ways to determine if an industrial or automotive lubricant is past its shelf life. For example, the shelf life of oil may be expired if it exhibits the following:
- Cloudy appearance
- Strong, unnatural odor
- Significant sediment buildup (some sediment buildup is natural)
Similarly, greases also exhibit certain characteristics when past the shelf life. The things to look for regarding greases include:
- Excessive oil separation (a little is normal)
- Consistency change
- Unnatural color or odor
- Change in texture
Over time, the oil naturally separates from most grease. But if the storage temperature is more than 110° Fahrenheit, the separation accelerates. Greases should be stored in a temperature range between 32° and 75° Fahrenheit.
Water-based lubricants such as metalworking coolants will often exhibit similar traits, such as odors, sediment, and separation of the oil and water. Likewise, bulging containers is another indicator that the fluid is past its useful life.
Lastly, other lubricants, such as moisture-sensitive ones, or those with high-additive content, may exhibit phase separation, heavy sediment drop out, or a hazy appearance.
To optimize shelf life, lubricants should be stored in a dry, temperature-stable environment. Any excessively hot or cold storage periods could affect the shelf life. Heat increases the rate of oil oxidation which can affect viscosity and deposit formation. Cold temperatures, on the other hand, can lead to wax and sediment problems. Finally, fluctuating temperatures may lead to expansion and contraction which, in turn, creates atmospheric contamination.
Some things to know regarding lubricant storage include:
- Light can change the appearance and/or color of lubricants, always store in a dark, dry place
- Avoid storing containers outside. Water intrusion can promote microbial growth and affect some additives, forming an insoluble substance in sealed, opaque containers; moisture on top of a drum can still get into the barrel even if the bung caps are tightly secured
- Never store in an environment that is dusty or dirty
- Oxygen and carbon dioxide will affect viscosity – keep containers sealed from the atmosphere
Whether it’s a machine shop, a manufacturing facility, an automotive repair shop, or any other business that relies on oil, greases, coolants, and other fluids, it’s important to use lubricants that protect equipment and keep it running in peak condition. Proper inventory management will ensure you are maximizing your lubricant investment.
For help with inventory management or determining the shelf life of your oil and fluids, contact us or reach out to your Account Manager.