TLT: When did you first get involved with environmentally friendly lubricants?
Adams: My first significant experience with environmentally friendly lubricants (EALs) occurred when I joined RSC Bio Solutions five years ago. Prior to working for RSC Bio Solutions, I made some lithium greases with canola base oils that were oxidatively unstable.

TLT: How has the landscape for EALs changed since then?
Adams: We were limited to using only vegetable base oils 25 years ago, and since then there have been a number of base fluids developed that meet the EPA’s definition of an EAL. Vegetable oils or triglycerides are still used; certain synthetic esters and PAGs also are used. The base fluid that we are using to develop high-performance, commercially viable lubricants are primarily based on PAO and hydrocarbon-related base fluids.

TLT: What are the largest end-use markets demanding EALs?
Adams: The marine industry is our largest end-use market. The use of EALs in the marine market is primarily due to legislation in place for the marine industry for ships operating in U.S. territorial waters that are larger than 79 feet. This legislation was initially adopted in 2013 as the Vessel General Permit or VGP 2013. 

Another growth area for this industry is in risk mitigation associated with spills. Lubricant spills that occur on heavy equipment and waste management equipment, for example, are typically caused by pump or seal failures. These spills are subject to clean-up costs and fines. The use of EALs significantly reduces the costs associated with spills and could lead to a different direction in the press coverage when the spill is reported to the public. Construction over waterways and environmentally sensitive areas utilize EALs for the same reasons.

TLT: Are there new regulations coming online that will make significant changes in the future?
Adams: New legislation is being considered by the EPA that could strengthen or weaken the current guidelines. The current VGP guidelines target oil/water interfaces where the lubricant could be released into the environment. In early 2020 the EPA could reduce the demands initially set forth in VGP 2013 guidelines. 

After the EPA issues those guidelines, there will be a comment period, and after the comments are reviewed, the U.S. Coast Guard will decide how best to enforce the guidelines set forth by the EPA, and the VGP will be replaced by the Vessel Incidental Discharge Act. We believe it is possible that the demands of guidelines could be reduced by the EPA since commercial entities are actively pursuing a less stringent set of environmental requirements.

TLT: What is the most difficult performance parameter for an environmentally friendly lubricant?
Adams: Finished hydraulic fluids and gear oils made with synthetic esters, polyalkylene glycol and triglyceride-based lubricants have hydrolytic stability concerns that need to be overcome. The base fluids that we utilize do not have significant water stability issues, and we focus our developmental efforts toward improving the oxidation stability and extreme-pressure performance of the lubricant.

Greases used in either marine applications or outdoor environments are exposed to water, and we formulate our products to have exceptional water spray off and water washout performance. Once again, the oxidation stability and extreme-pressure profiles of the grease need to be targeted.

TLT: Are there applications where an EAL would be preferred but it is not yet possible to meet the performance demands?
Adams: Until recently, some of the high-load grease applications that require four-ball weld performance to be above 800 kgf were not attainable. However, recently there have been products developed to address those applications. 


The EPA has started plans to replace 2013's Vessel General Permit with the Vessel Incidental Discharge Act, which could be less stringent.

TLT: Comparing the U.S., Europe and Asia, which region has the most interest in EALs? Due to current VGP guidelines, the majority of EALs are used on ships in U.S. territorial waters. Do you think this will change in the future?
Adams: The EU currently has a significant amount of interest; however, Ecolabel is not enforced in the same manner throughout Europe. The Asian market recently has been looking into developing guidelines relating to the use of EALs.

We believe there will continue to be environmental regulations for oil/water interfaces on ships. Regulations will continue to evolve that we believe will improve the quality of our seas. 

TLT: Is there a universal definition of EAL, or does each region and market define them differently?
Adams: While there is not a universal definition of an EAL, the VGP 2013 definitions are generally accepted to describe an EAL. The VGP 2013 defines an EAL to possess the following characteristics:

• Must biodegrade by 60% or more after 28 days
• Must be minimally toxic to certain marine species
• Must not bioaccumulate in the fatty tissue of fish.

In addition, if a product can be approved under Ecolabel as an EAL then the lubricant also can be classified as VGP compliant. 

TLT: What are the most important characteristics of an EAL?
Adams: EALs need to perform as well or better than mineral oil-based lubricants in terms of hydrolytic stability, seal compatibility, oxidation stability and extreme-pressure protection.

Perhaps at one time the performance characteristics described immediately above were not readily attainable; however, new base fluids and additives have led to dramatic improvements in the previously stated performance characteristics of EALs. 

TLT: When developing a new formulation, do you start with environmentally friendly ingredients and work to meet the performance requirements or start with a standard formula then work to make it environmentally friendly?
Adams: My suggestion is to start with an environmentally friendly base fluid such as a triglyceride, a synthetic ester, a polyalkylene glycol or a PAO and hydrocarbon-related base fluid to begin the formulation and move forward. Base fluids that are defined as EALs vary significantly in terms of performance. After the base fluid is selected, a review of the lubricant substance classification (LuSC) list is required to determine the additives that can be used to meet the desired performance. The LuSC list was developed by the EU and can also be used to determine acceptable treat rates for each component. 

Metals that are typically used in mineral oil-based lubricants, like zinc and antimony, cannot be used in EALs. Consequently, most low-cost EP/AW additives are out of the question. There are new additives and base fluids being developed to improve the performance and cost of EALs. We are optimistic there will continue to be significant growth in the use of EALs for land and sea applications.

You can reach Douglas Adams at dadams@rscbio.com.