The test method provides a relatively simple method for determination of the concentration of RDP without the need for specialty equipment built expressly for such purposes.

Using this test method will afford investigators of radon in dwellings a technique by which the RDP can be determined. The use of the results of this test method are generally for diagnostic purposes and are not necessarily indicative of results that might be obtained by longer term measurement methods.

An improved understanding of the frequency of elevated radon in buildings and the health effect of exposure has increased the importance of knowledge of actual exposures. The measurement of RDP, which are the direct cause of potential adverse health effects, should be conducted in a manner that is uniform and reproducible; it is to this end that this test method is addressed.

1.1 This test method provides instruction for using the grab sampling filter technique to determine accurate and reproducible measurements of indoor radon decay product (RDP) concentrations and of the working level value corresponding to those concentrations.

1.2 Measurements made in accordance with this test method will produce RDP concentrations representative of closed-building conditions. Results of measurements made under closed-building conditions will have a smaller variability and are more reproducible than measurements obtained when building conditions are not controlled. This test method may be utilized under non-controlled conditions, but a greater degree of variability in the results will occur. Variability in the results may also be an indication of temporal variability present at the sampling site.

1.3 This test method utilizes a short sampling period and the results are indicative of the conditions only at the place and time of sampling. The results obtained by this test method are not necessarily indicative of longer terms of sampling and should not be confused with such results. The averaging of multiple measurements over hours and days can, however, provide useful screening information. Individual measurements are generally obtained for diagnostic purposes.

1.4 The range of the test method may be considered from 0.0005 WL to unlimited working levels (WL), and from 40 Bq/m3 to unlimited for each individual randon decay product.

1.5 This test method provides information on equipment, procedures, and quality control. It provides for measurements within typical residential or building environments and may not necessarily apply to specialized circumstances, for example, clean rooms.

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. See Section for additional precautions.