Shelf life
Evan Zabawski | TLT From the Editor August 2018
Does oil have an expiration date?
Ultimately it may not be up to the lubricant manufacturer to identify a specific date but, rather, a specific time frame from receipt.
Photo courtesy of http://xfittrainingeastbay.com.
One of the more difficult questions to answer definitively is, “What is the shelf life of a lubricant?” The answer is not easily found on the packaging, and word-of-mouth answers can be as short as six months, which begs the follow-up question: “From the time of blending, receipt or opening?”
The apparent answer would be for packaging to mimic the food industry and employ expiration dates, but this is not without its own issues. The average consumer wastes a considerable amount of food each year, and one of the prime culprits is the “best before” date, which many interpret to mean there is a health concern after that date.
The qualification to any of these statements is the implication of proper storage and handling, namely refrigeration and sealed packaging or, occasionally, storage away from sunlight. Once packaging is opened, a new timer is started, and that timer speeds up considerably without required refrigeration. This same qualification about proper storage applies to lubricants.
Of the lubricant suppliers who publish shelf-life values, which range from two to five to 10 years, they invariably qualify the time frame as occurring in its sealed and original container, stored indoors or under protection from outside elements. But just because a container of lubricant is open does not necessarily mean that its timer speeds up, provided the container is re-sealed or protected with a decent desiccant breather.
But even with proper storage a “best before” date is not meant to be a “don’t use after” date. To this end, some food producers have altered the language of the expiration date to wording like “use by,” “freeze by” or “sell by.” These are meant to help the consumer understand the food is literally “best before” a certain date, alluding to quality and not safety.
Would it make sense for lubricants to have a “use by” date? Assuming the date was ascertained using some valid and logical determination, there is certainly potential; however, without a government regulation this might not be the case. In the food industry there are many products carrying unreasonable expiration dates and even some which are not required (i.e., honey).
The consumer needs to trust that a given date is symbolic of some performance issue and not simply a marketing tool to encourage higher sales. The issue then comes down to stability, since lubricants do not degrade at a significant rate under normal storage conditions, but stability largely depends on proper storage and handling. We have come full circle.
Ultimately it may not be up to the lubricant manufacturer to identify a specific date but, rather, a specific time frame from receipt. This puts the onus for proper storage on the consumer, who wields the power to shorten or extend the product’s shelf life. The wording would have to be something like: “This product is stable for up to five years when stored properly in its sealed, original container.”
Such a statement makes it clear that the entire time frame cannot be achieved once the container has been opened. While one might argue that, without a fixed date, it could be difficult to judge if an open container is definitely less than five years old, the rebuttal would be that any container not easily consumed within five years of opening presents a greater inventory-related question than stability.
Perhaps, after all, there is a reason that lubricants do not come with an expiration date of any kind, namely that the variability of consumer storage and handling plays too strong of a role. Ultimately it should be accepted that lubricants do not expire quickly, but improper storage will certainly spell their untimely demise.
Evan Zabawski, CLS, is the senior technical advisor for TestOil in Calgary, Alberta, Canada. You can reach him at ezabawski@testoil.com.