A knowledge of the quantity of oil and grease present in a waste is helpful in overcoming difficulties in wastewater treatment plant operation, in determining plant efficiencies, and in controlling the subsequent discharge of these materials to receiving streams.

When oils and greases are discharged in wastewater or treated effluents, they often cause surface films and shoreline deposits.

1.1 These test methods cover the estimation of oil and grease in water and wastewater by a gravimetric determination of fluorocarbon extractable substances from an acidified sample. Also included in this estimation of oil and grease are any other compounds soluble in chlorofluorocarbon-113 and non-volatile under the conditions of test.

1.2 The following two test methods are included:

1.3 These test methods are applicable to natural waters and domestic wastewaters. They are also suitable for most industrial wastewaters, although certain wastes may yield low results because of the presence of either excessive concentrations of natural greases or synthetic or modified compounds that are not well recovered by these test methods.

1.4 These test methods measure those groups of substance called oil and grease, whether soluble or insoluble, polar or non-polar, or biological or mineral in origin, to the extent these substances partition from the matrix into chlorofluorocarbon-113 and are not volatilized under conditions of the test. (See the Introduction and Section of these test methods.)

1.5 Because these test methods include an acidification step prior to extraction, soluble metallic soaps are hydrolyzed and recovered as fatty acids in the extraction step.

1.6 These test methods were fully validated by collaborative testing in reagent Type IV water. The information on precision may not apply to other waters. Note 1Refer to companion procedures (Test Method D 3921).

1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.8 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 and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 12.1, 13.2, 20.1, and 20.5.