Does your environmentally acceptable lubricant put your marine operation at risk of a federal violation while sailing North American waters? It seems counter-intuitive, but it may be the case.

Introduction of the Vessel General Permit in December 2013, covering ships greater than 79 feet in length, and the Small Vessel General Permit a year later, for those less than 79 feet, have brought major changes in design and maintenance practices for commercial marine vessels sailing U.S. waters. These U.S. Environmental Protection Agency regulations mandate use of approved Environmentally Acceptable Lubricants (EALs) in applications referred to as oil-to-sea interfaces – where often the only thing standing between water and machinery is a simple seal or gasket.

The intent behind EAL requirements is to greatly reduce or eliminate the long-term environmental damage caused by free oil discharges, whether from submerged parts such as propellers, thrusters and stern tubes or from on-deck equipment like cranes, winches and hoists. To be considered an acceptable lubricant, a product must be readily biodegradable, decaying by at least 60 percent within 28 days. It must also pass very low aquatic toxicity criteria in order to have the lightest possible impact on the marine environment. Finally, EALs must not be bio-accumulative in any organism.

While EALs have received plenty of attention recently, an often overlooked or misunderstood part of the equation for marine lubricants is the U.S. Clean Water Act. The irony is that some products designed to protect the environment can be classified as pollutants under these regulations. This is because spills of any oil – petroleum, vegetable or other, including biodegradable types – are a violation of the Clean Water Act.

Any violation, negligent or non-negligent, can result in substantial fines and other financial liabilities such as cleanup efforts and site remediation. Cleanup can be especially costly. Mopping up oil spills is rarely easy or straightforward, as the ideal conditions seldom or never actually exist. Strong river or tidal currents can combine with wind and waves to make cleanup difficult. Discharges are most likely to occur because of excessive strain on hydraulic equipment in poor weather conditions and rough seas, creating dangerous or futile attempts at spill recovery.

Similar pollution regulations govern Canadian waters. Two major spills of non-toxic, food grade canola oil in the Vancouver, British Columbia, harbor in 1999 and 2000 resulted in over 2,000 seabird fatalities due to hypothermia, and required the same cleanup and wildlife rescue efforts as a spill of petroleum oil. Transport Canada, which enforces the pollution control regulations of the Canada Shipping Act, has realized that even biodegradable oil can be harmful or fatal to marine birds and mammals.

The Pollution Prevention section of the Canada Shipping Act defines petroleum hydrocarbons (oil) as pollutants, along with any substance that can have detrimental effects on humans, animals and plant life. This encompasses any oil that can interfere with marine wildlife, even if it is non-toxic. Marine pollution offenses are often met with heavy fines and cleanup costs.

Regulatory Compliance

The basic determinant of what is considered an oil under the U.S. Clean Water Act is the non-sheening rule (40 CFR Part 435). Under this rule, discharge of any substance creating a visible sheen on the water – regardless of whether or not it is an EPA-approved EAL – violates the Clean Water Act.

Of course, most approved EALs are oils of some type. While these products may meet the criteria of ready biodegradability, low toxicity and lack of bioaccumulation, as oils they will float, causing a slick or sheen on the surface of the water in the event of a spill or discharge.

Although EALs are meant to reduce or eliminate the environmental impact and financial burdens associated with accidental lubricant spills in water, spills of oil-based EALs violate other pollution prevention legislation. Further, the EPA is aware that chemicals (such as dispersants) are added to some EAL products to mask their visible sheen.

However, if an EAL is not an oil and does not create a sheen on the water, it is exempt from the Clean Water Act as well as oil spill cleanup obligations. When investing large sums of money to convert machinery to an approved EAL, it is possible for marine operators to both comply with the VGP and mediate the financial and environmental risk of accidental lubricant discharges.

The EPA has determined that four major types of lubricants meet the necessary criteria to be classified as approved EALs. These include vegetable oils, synthetic esters, biodegradable polyalkylene glycols and water (used to lubricate some stern tube bearings). While some lists of EAL products include polyalphaolefins, PAOs were not included on the EPAs 2011 information sheet.

Vegetable Oils

Natural triglycerides or vegetable oils are usually made from either canola or soybean. Being both readily biodegradable and very low in toxicity, vegetable based oils are often given preference over other types of EALs by environmentalists who consider them renewable resources. Vegetable oils come at reasonable prices and are the only type of biodegradable oils with which most people are familiar.

From a practical standpoint, vegetable oils have very good lubricity at mild operating temperatures but lack stability at higher temperatures. Oxidation occurs rapidly at elevated temperatures normally tolerated by other oils, leading to accelerated varnish deposits. Much shorter drain intervals are required to avoid degradation, but often equipment operators push these types of fluids past their capabilities. In the long run, particularly without proper care, these fluids can result in higher costs from frequent oil changes, increased maintenance and equipment downtime.

Vegetable oils can also present challenges in cold climates, such as parts of the U.S. Midwest, Alaska and much of Canada. While some products show excellent viscosity indexes, their pour points are not conducive to use in these areas.

Another challenge associated with vegetable oils is hydrolytic stability, or how the product behaves when it comes into contact with water. Vegetable oils react readily in the presence of moisture, forming acids and sludge. These acids can be corrosive to equipment components and seals and can soften hydraulic hoses, leading to premature blowouts.

From a compliance standpoint, vegetable oils tick the EAL box. But because they are oils, any spill in North American waters risk penalties for Clean Water Act or Canada Shipping Act violation.

Synthetic Esters

Synthetic esters may be developed from plant esters and offer significantly better performance over vegetable oils. They provide oxidation stability similar to or better than that of conventional mineral oil, as well as improved thermal stability, V.I. and lubricity at elevated temperatures.

These products are costly to produce and can be the most expensive EALs on the market, with some European products costing over $60 per gallon. Many of the biodegradable oils or EALs offered in the marketplace are actually a blend of vegetable oils and synthetic esters, offering some of the performance advantages of the synthetic esters and the lower cost of the vegetable oil.

Some synthetic esters can offer low pour points and viscosity indexes of over 200, making them suitable for cold temperature operations. Longer fluid life can reduce maintenance costs and help to offset higher lubricant costs. However, synthetic esters – like mineral oils, vegetable oils and PAOs – will still form varnish if exposed to elevated temperatures over time. Most oils, including synthetic esters, can also react with moisture and hydrolyze in the same manner as vegetable oils.

And again, we find the same problem with compliance: While synthetic esters are classified as EALs, they are still oils, and spills will fetch a fine for violating North American environmental regulations.

Polyalkylene Glycol

Like esters, polyalkylene glycol lubricants can be tailored for certain characteristics or capabilities in order to suit the application. Anhydrous, water soluble PAGs are particularly suited to marine applications.

PAGs possess good load-bearing and lubricating abilities, and can tolerate heat that would readily create varnish in other fluids. When a PAG does begin to oxidize, the polar fluids molecular structure suspends oxidation byproducts in solution, preventing deposits. On the other side of the thermometer, many PAG fluids have V.I.s over 200 and pour points below -50 degrees C.

PAGs do not react with water, so corrosive acids and gum are not produced as with other base stocks. These lubes can handle up to 1.5 percent water contamination before performance begins to diminish. While there is no saturation point, viscosity and lubricity will slowly be reduced as the water content is increased.

Common concerns about PAGs include their incompatibility with conventional oils, so equipment changeover is accomplished by thorough flushing when switching from a mineral oil fluid. Water-soluble varieties of PAGs will completely separate from conventional oil, and any oil accidentally poured into the hydraulic reservoir can be skimmed off the top. PAGs are, however, incompatible with some oil-based equipment coatings.

Although these products are derived from natural gas and not considered biobased, they are readily biodegradable and are classified as practically non-toxic by the EPA and non-toxic by Transport Canada. Because water-soluble PAG fluids are not oils, they will not form a visible slick or sheen on the surface of the water. Instead, they dissolve and dissipate when discharged into water, remaining in compliance with North American environmental regulations.

Many equipment managers avoid using EALs if they can do so, as these lubricants are generally viewed as costly, inferior products that require more maintenance while producing fewer benefits than traditional oils.

Polyalkylene glycol fluids reduce or eliminate many of the problems associated with standard EALs while bringing vessels into compliance with environmental regulations and reducing risk in case of accidental discharge into water. Further, they can be less expensive than many synthetic esters and offer more in performance, fluid life and value.

Considering the lighter environmental impact and level of compliance provided, along with reduced liabilities in the event of a spill, water-soluble PAG lubricants seem to be the clear choice for marine operators in North American waters.

Jim Burton is fuels and marine lubricants executive at M. R. Smith Ltd., and has more than 35 years of lubricants and petroleum industry experience. For information, email him atjamesburton@shaw.ca or jim@mrsmithltd.com.