Oil and grease is one of the five conventional pollutants covered by the 1974 Clean Water Act. The measurement of oil and grease is included in all of the National Pollution Discharge Elimination Systems (NPDES) permits, all pre-treatment permits, and all Industrial Effluent Guidelines. It is important to note that it is the 2nd most-enforced-against parameter--2nd only to pH. As a result of the Montreal Protocol, which entered into force in 1989, EPA was required to move from a Freon extraction infrared-based determination method to a n-Hexane extraction mass-based determination method, creating four new issues: 1) a flammable liquid is required, 2) n-Hexane is a known neurotoxin, 3) the analytical time is significantly increased, and 4) we are left with a large amount of n-Hexane for disposal. An estimated 1.1 million liters of n-Hexane is used each year for EPA Method 1664A analyses.

A new method “ASTM D7575 – Standard Method for Solvent-Free Membrane Recoverable Oil and Grease by Infrared Determination” developed by Orono Spectral Solutions will remedy the four issues listed above by removing the use of hexane or any other solvent from the analysis or cleanup. Furthermore, easy adoption of this method is anticipated because it incorporates central elements of current and past methodologies.