5.1 The presence and concentration of total oil and grease as well as total petroleum hydrocoarbons, in domestic and industrial wastewater is of concern to the public because of its deleterious aesthetic effect and its impact on aquatic life.

5.2 Regulations and standards have been established that require monitoring of total oil and grease as well as total petroleum hydrocarbons in water and wastewater.

1.1 This test method covers the determination of total oil and grease (TOG) and total petroleum hydrocarbons (TPH) in water and waste water that are extractable by this test method from an acidified sample with a cyclic aliphatic hydrocarbon (for example cyclohexane, cyclopentane) and measured by IR absorption in the region from 1370 cm^-1 to 1380 cm^-1 (7.25 μm to 7.30 μm) using a mid-IR laser spectrometer. Polar substances are removed by clean-up with Florisil.2

1.2 This test method also considers the volatile fraction of petroleum hydrocarbons, which is lost by gravimetric methods that require solvent evaporation prior to weighing, as well as by solvent-less IR methods that require drying of the employed solid phase material prior to measurement. Similarly, a more complete fraction of extracted petroleum hydrocarbons are accessible by this test method as compared to GC methods that use a time window for quantification, as petroleum hydrocarbons eluting outside these windows are quantified too.

1.3 This test method covers the range of 0.1 mg/L to 1000 mg/L and may be extended to a lower or higher level by extraction of a larger or smaller sample volume collected separately.

1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.