ASTM D5864 and ASTM D6731, Lubricant Biodegradation Test
Concept
ASTM D5864 and D6731 are two ASTM methods specifically designed for the biodegradation test of lubricants or their components. ASTM D5864 measures the CO2 evolution, which is equivalent to the OECD 301B method. ASTM D6731 measures the oxygen consumption, which is equivalent to the OECD 301F.
ASTM6731 is our preferred method for lubricant test due to its simple system setup and high applicability.
Brief overview of the two methods
ASTM D5864
Similar to the OECD 301B CO2 Evolution Test, ASTM D5864 measures the CO2 evolution to reflect the biodegradation of fully formulated lubricants or their components, based on the exposure to activated sludge from municipal wastewater treatment plant as the inoculum under laboratory conditions.
This method is designed for all lubricants that are not volatile and are not inhibitory to the inoculum at the test concentration. It is intended to specifically address the issues associated with insoluble substances and complex mixtures that are commonly found in lubricants.
It can handle materials that are insoluble and/or absorbing. Good dispersion is usually required for better performance.
Test substances that achieve high levels of biodegradation are assumed to be easily biodegradable in most aerobic aquatic environments.
ASTM D6731
Similar to the OECD 301F Closed Respirometer Test, ASTM D6731 measures oxygen consumption to reflect the biodegradation of fully formulated lubricants or their components, based on the exposure to activated sludge from municipal wastewater treatment plant as the inoculum under laboratory conditions.
It has the highest applicability among all other methods and can handle materials that are highly soluble, poorly soluble, insoluble, volatile, involatile, and/or adsorbing. Good dispersion with continuous mixing is usually required for better performance.
Test substances that achieve high levels of biodegradation are assumed to be easily biodegradable in most aerobic aquatic environments.
ASTM D6731 is our second recommended method (following OECD 301F ) due to its simple experimental setup and high applicability.
Please refer to the page "Test Method Overview" for more information.
Applicabilities
| Test | Analytical method | Sample info required | Poorly soluble | Volatile | Adsorbing |
|---|---|---|---|---|---|
| ASTM D5864 (Lubricant - CO2 evolution) | CO2 evolution | Carbon content | + | - | + |
| ASTM D6731 (Lubricant - Closed respirometer) | Oxygen consumption | ThOD or COD | + | +/- | + |
