The dioctyl phthalate (DOP) smoke test is a highly sensitive and reliable technique for measuring the fine particle arresting efficiency of an air or gas cleaning system or device. It is especially useful for evaluating the efficiency of depth filters, membrane filters, and other particle-collecting devices used in air assay work.

Formerly under the jurisdiction of Committee D22 on Sampling and Analysis of Atmospheres, this practice was withdrawn in December 2004. This practice is being withdrawn because the procedure is 34 years-old and the apparatus identified (the Optical Owl) is no longer available.

1.1 The dioctyl phthalate (DOP) smoke test is a highly sensitive and reliable technique for measuring the fine particle arresting efficiency of an air or gas cleaning system or device. It is especially useful for evaluating the efficiency of depth filters, membrane filters, and other particle-collecting devices used in air assay work.

1.2 The technique was developed by the U.S. Government during World War II. Its validity for use in evaluation of air sampling media has been well demonstrated.

1.3 Although a little latitude is permissible in the associated equipment and in the operation method, experience has shown the desirability of operating within established design parameters and recognized test procedures.

1.4 This practice describes the present DOP test method, typical equipment, calibration procedures, and test particles. It is applicable for use with commercially available equipment.

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 and health practices and determine the applicability of regulatory limitations prior to use. For specific safety precaution, see 6.1.