There is growing concern regarding the environmental impact and associated costs of lost petroleum-based fluids. The National Oceanic and Atmospheric Administration (NOAA) estimates that more than 700 million gal of petroleum enter the environment each year, more than half of which is through irresponsible and illegal disposal. Industry experts estimate that 70 to 80% of hydraulic fluids leave systems through leaks, spills, line breakage, and fitting failure. Petroleum is persistent and toxic. It damages living organisms including plants, animals, and marine life for many years. In addition, the Coast Guard, EPA, and local governments are increasing the range of responsibility of lubricant releases including significant fines and clean-up costs.
In addition to regulatory pressure, equipment operators are frequently faced with clients and stakeholders who are concerned with petroleum-based hydraulic fluids getting into the environment. Even a small amount of petroleum could contaminate an area and cause it to be classified as hazardous.
Prevention is the best environmental protection
As demands on lubricant systems increase, the likelihood of accidental release of fluids also increases. Increased operating temperatures, pressures, and working cycles shorten the life of circuit components. The single best approach to protecting the environment, the equipment, and the operation is to prevent leaks and spills through good routine maintenance. A good preventative maintenance program will:
- Increase productivity because equipment is used more,
- Better utilize in-shop maintenance because there is less emergency work,
- Improve control of spare part inventory and reduce parts usage,
- Reduce equipment down time,
- Reduce safety hazards,
- Increase equipment life,
- Reduce fines and clean-up costs due to environmental release, and
- Reduce down time related to environmental release.
Even with the best maintenance practices, hydraulic leaks and spills are almost inevitable. With that in mind, more and more operators are exploring the use of environmentally preferable alternatives.
Bio-based means less regulation
There are increasing regulatory pressures from the EPA, Coast Guard, and other environmental organizations. While small releases will not result in a Resource Conservation and Recovery Act (RCRA) clean up, large spills will. All petroleum hydraulic fluid spills are “reportable events.” These events involve a great deal of clean-up cost, administrative procedures, and punitive fines that can range from tens of thousands to hundreds of thousands of dollars.
While spilling large quantities of biodegradable hydraulic fluid is still considered under RCRA to be a reportable event, agencies are required to evaluate “bio-based oils” differently than petroleum-based oils. As awareness of biodegradable fluid increases, state and federal agencies are becoming more lenient regarding fines and clean-up costs. In fact, there are several case studies of equipment releasing several hundred gallons of vegetable-based hydraulic fluid into environmentally sensitive areas with no fines and minimal clean-up expense. In most instances, the operator was able to continue working while clean-up efforts were underway. Since the fluids were biodegradable and non-toxic, there was no long-term negative effect to the ecosystem.
There is a common misperception that the Coast Guard or other agencies approve oils based on the oil not leaving a sheen. This is not true. The Coast Guard does not approve, recommend, or endorse any fluids. Furthermore, the Coast Guard does not approve or recommend any test procedures, but rather, follows United States statute laws. The oil sheen that is frequently referenced is inferred from the Clean Water Act as defining “any substance that leaves a sheen, emulsification, or discoloration, as a pollutant and be subject to appropriate fines and regulations governing pollutants.” The Coast Guard also relies on the guidelines as outlined by equipment manufacturers and highly favors the use of bio-based and biodegradable fluids. Figure 1 shows the process of biodegradation. Biodegradation is the process of chemical breakdown or transformation of a material caused by organisms or their enzymes.
There are two commonly used measurements for biodegradation. The first is “primary degradation” which measures reduction of the carbon and hydrogen bonds (C-H) in the initial solution; this is the reduction of the amount of the lubricant. The most widely used test that measures this decrease is the CEC-L-33-A-93.
The second measurement of biodegradation is “secondary degradation” or “ultimate degradation.” This measures the evolution of CO2 through the biodegradation. The usual test for this is the OECD 301or the ASTM D4684. Figure 2 shows both processes.