Biodegradable lubricants are used across a wide range of industrial applications, but many users aren’t entirely sure why they matter or what the different standards actually mean.
Whether you’re focused on compliance, spill prevention, or broader ESG goals, understanding what “biodegradable” really means and how it’s measured is key to making smart, responsible choices when selecting lubricants
What Is Biodegradability?
In the context of lubricants, biodegradability refers to a lubricant’s ability to be broken down by microorganisms into natural substances like carbon dioxide, water, and biomass. This process only occurs once the lubricant enters the environment—usually through a spill or leak—and requires conditions like moisture, oxygen, and microbial activity.
Biodegradability is evaluated using standardized lab tests. The most widely referenced is OECD 301B, which measures CO₂ evolution over 28 days. To be considered readily biodegradable, a lubricant must reach at least 60% degradation within a 10-day window during that 28-day test period.
Why It Matters
Biodegradable lubricants are essential for industries working in or around waterways, soil, or other sensitive ecosystems. Marine operations, forestry, agriculture, and hydropower facilities are common examples. In these settings, spills or leaks are almost inevitable.
In the U.S., the EPA’s Vessel General Permit (VGP) and revised standards under the Vessel Incidental Discharge Act (VIDA) require the use of Environmentally Acceptable Lubricants (EALs) in marine oil-to-sea interfaces. These lubricants must be readily biodegradable, minimally toxic, and non-bioaccumulative.
Regulations aside, choosing biodegradable lubricants can reduce cleanup costs, help companies meet sustainability targets, and protect brand reputation.
How Biodegradability Is Measured
Lubricants are typically tested according to the following categories:
- Readily Biodegradable: ≥60% degradation within 28 days and a 10-day window (OECD 301B/F)
- Ultimately Biodegradable: ≥60% degradation in 28 days but without the 10-day requirement
- Inherently Biodegradable: Between 20–60% degradation—not fast or complete enough to meet regulatory standards
Other standards include ASTM D5864 and the CEC L-33-T-82, which are also used to assess lubricant biodegradability under controlled conditions.
What Types of Lubricants Meet These Standards?
- Readily Biodegradable: Synthetic esters (HEES), vegetable oil-based fluids (HETG), and some polyalkylene glycols (HEPG)
- Ultimately Biodegradable: Certain specialty esters and advanced synthetics
- Inherently Biodegradable: Most mineral oils and lubricants with conventional additive systems
It’s important to note: biobased does not necessarily mean biodegradable. And while synthetic lubricants can be formulated for biodegradability, many are not.
The Additive Factor
Even if a base oil is biodegradable, the additive package can lower or negate the overall biodegradability of the formulation. Common antiwear agents, antioxidants, and thickeners are often not biodegradable and may carry aquatic toxicity. Balancing performance and environmental impact remains a core challenge for formulators.
That’s why certifications like the EU Ecolabel and inclusion on the LuSC list matter—they verify both base oils and additives meet environmental thresholds.
Bottom Line
Biodegradable lubricants offer a responsible alternative in sensitive applications, but only if they meet recognized standards. To make the right choice, focus on validated testing methods, proven formulations, and total formulation integrity, including additives.
Let us know if you’d like help selecting the right biodegradable lubricant for your application.