Biodegradability Primer

When we think of something as biodegradable it means that a product can be broken down and assimilated, by natural means, back into common elements like carbon, oxygen and hydrogen. Of course, everything on the planet is “biodegradable,” … eventually; this term is only meaningful within a specific time limit.

There are some products on the market labeled as “inherently biodegradable” or worse, just “biodegradable.” WISE Solutions lubricants designed to meet ASTM standard D5864 have been tested to achieve “Ultimate Biodegradability,” where “Pw1” is the highest standard – the product is rapidly absorbed (eaten) by microbacteria in an aquatic environment. Unlike “inherent” biodegradability, and biodegradability represented by a host of other standards, WISE products are more biocompatible, as they do not persist and accumulate when lost to the environment.

Conversion and release of carbon dioxide is the most important true indication of biodegradation. Products that claim to be only “inherently biodegradable” (e.g., ChevronTexaco hydraulic fluids, such as Chevron Clarity Hydraulic Oils AW) do not adhere to a specific maximum timeframe for biodegradation, and would be better termed “inherently polluting.” Certainly, these products do eventually degrade (like everything does), but would be subject to all fines, cleanup regulations, and long-term remediation as with 100% petroleum products. Any product that is 20% or more biodegradable can be called “inherently biodegradable.” Unless clearly explained (“Warning: this product is not Readily or Ultimately Biodegradable”), this amounts to greenwash or at best “green veneer” (appearing to be green on the surface) by the manufacturer, and uninformed customers may have false security assuming that their disposal, spill or leakage risks are handled.

Too many customers have been falling for this deception, which performs a disservice to the environment and to the renewable lubricant industry as a whole … until now.

Online discussion groups, customer forums, and industry symposia are helping to educate those who care about the environmental and health effects of their product choices. The WISE brand is positioned to appeal to this segment of the addressable market, but will also appeal to those who seek a high-performance lubricant as their first priority. See Value Proposition in the WISE business plan for elaboration on this point.

The illustration at the right shows the time of degradation compared to the conversion to CO2 (from the Biodegradable Products Institute). The minimum standard for ASTM D-5864 Pw1 is at least 60% conversion to CO2 within 28 days.

International standards bodies such as CEC (Coordinating European Council), the DIN CERTO (a German standards organization; stands for Deutsches Institut für Normung), and ASTM (American Society for Testing Materials) define precisely and verifiably the maximum length of time for lubricants to biodegrade, and the degree to which they ultimately biodegrade within that time period. The majority of WISE products meet ASTM D-5864 Aerobic Aquatic Biodegradation of Lubricants, Pw1, the “ultimate” biodegradation rating.

Another test method defined by the CEC, the L-33-T-82 (now listed as CEC L-33-A-934) applies to most organic compounds, whether soluble or insoluble in water. It determines the overall biodegradability of hydrocarbons, and was developed to characterize the biodegradability of outboard engine oils on Lake Constance (also known as Bodensee – Central Europe’s second largest freshwater lake, covering 220 square miles), due to the accumulation of mineral oils which tainted fish. The CEC test is accepted in a number of Blue Angel Environmental Labels, and requires 80% or greater biodegradability. The German Blue Angel scheme does not intend to produce guidelines for “enclosed” systems.

Although the industry, including the ASTM, ISO, OECD, U.S. EPA, and the EUC, is now accepting the percent of theoretical CO2 as the method for determining the biodegradation of lubricants, the CEC method has identified certain trends for biodegradation of various types of oils, described below.

Biodegradability Test Results for Common Oils
Oil Type	Amount Biodegraded
Mineral Oil	15 - 35%
White Oil - mineral base	25 - 45%
Natural & Vegetable Oil	70 - 100%
PAO (Synthetic)	5 - 30%
Polyether (used in making rigid polyurethane foam)	0 - 25%
Polyisobutylene (PIB)	0 - 25%
Phthalate & Trimellitate Esters	5 - 80%
Polyols & Diesters	55 - 100%
S. Harold, Biodegradability: Review of the Current Situation, 1993, Lubrizol Corporation

There are only two categories of oils that can ultimately biodegrade in a reasonable timeframe, so beware of misleading claims by certain petroleum companies.

In general, CEC L-33-A-934 refers to “Readily Biodegradable,” which is less stringent than the ASTM D-5864 Pw1 “Ultimate” standard. Despite being convenient and easy, the CEC test only measures the IR absorbance, not the water-soluble metabolites which are poorly extractable and therefore, cannot measure extensive degradation or mineralization. This would require a parallel test measuring oxygen consumption or carbon dioxide evolution. There is also no clear structural criterion which can be adopted to compare biodegradabilities of various structure types.

See www.wiserenewables.com for further information about WISE ultimate performance, renewable biolubricants for a wide variety of applications.