There are 4 common tests to determine organic pollution in wastewater:  BOD (or CBOD)CODTOC, and Oil & Grease (O&G).

Grease-clogged sewer pipe.

Oil & Grease testing determines the amount of non-volatile hydrocarbons (i.e. petroleum derivatives), vegetable oils, animal fats, waxes, soaps, greases and related material in a sample. Another name that better describes the test is n-Hexane-Extractable Materials (HEM), as this test measures only what is extractable by the solvent n-hexane. 

There are two types of O&G reporting: TOTAL O&G (HEM Oil& Grease) or POLAR/NON-POLAR (SGT-HEM; Non-polar Material). "Non-polar" materials are the portion of the oils and greases that derive from petroleum products.  "Polar" is everything else. Requesting the polar/non-polar option gives an idea of the source of your O&G contamination.  It requires an extra step in the method, and so costs a bit more.

O&G testing is most often requested by water treatment facilities and industries whose processes generate fats and oils.  O&G released to the environment not only clogs pipes, it's bad for aquatic life, and creates ugly slimes.

-- from Michigan Department of Environmental Quality


Cole Parmer's Environmental Express, "Understanding Oil and Grease" (.pdf)

EPA Method 1664, Revision B (2010, 35 pg. pdf)

Michigan Department of Environmental Quality, "Oil and Grease" (powerpoint)

 "Cease the Grease" webpage from Berwick Sewer District

MEL Test Method for O&G

EPA Method 1664A (rev. 2/99) (NPDES compliant)

aka SW846 9070A (RCRA compliant)

Sample Requirements

*NOTE: O&G sampling must be a GRAB sample; not composite.  Composite results should only be determined by averaging multiple grab samples.


Container: amber glass, teflon-lined top (leave a little air space at top to prevent accidental spilling)
Volume: 1L
Hold Time: 28 days
Preservation: H2SO4 or HCl to pH <2; ≤6°C


Container: amber glass 
Hold Time: n/a
Preservation: ≤6°C

See Also...

Total Organic Carbon (TOC)
Total Carbon (TC)
Total Inorganic Carbon (TIC)
Dissolved Organic Carbon (DOC)