An ongoing research program has been established to experimentally verify the application of the Gy theory to environmental samples, which serves as a supporting basis for the materials presented in this guidance. Research results from studies performed by the United States Environmental Protection Agency (U.S. EPA) have confirmed that the application of the Gy sampling theory to environmental heterogeneous particulate materials is the appropriate state-of-the-science approach for obtaining representative laboratory subsamples. This document provides general guidelines for obtaining representative subsamples for the laboratory analysis of particulate materials using the 'correct' sampling practices and the 'correct' sampling devices based on Gy theory. Besides providing background and theory, this document gives guidance on: sampling and comminution tools, sample characterization and assessment, developing a sampling plan using a general sampling strategy, and reporting recommendations. Considerations are given to: the constitution and the degree of heterogeneity of the material being sampled, the methods used for sample collection (including what proper tools to use), what it is that the sample is supposed to represent, the mass (sample support) of the sample needed to be representative, and the bounds of what 'representative' actually means. A glossary and a comprehensive bibliography have been provided, which should be consulted for more details.

"November 2003."; "EPA600-R-03-027." Includes bibliographical references.

An ongoing research program has been established to experimentally verify the application of the Gy theory to environmental samples, which serves as a supporting basis for the materials presented in this guidance. Research results from studies performed by the United States Environmental Protection Agency (U.S. EPA) have confirmed that the application of the Gy sampling theory to environmental heterogeneous particulate materials is the appropriate state-of-the-science approach for obtaining representative laboratory subsamples. This document provides general guidelines for obtaining representative subsamples for the laboratory analysis of particulate materials using the 'correct' sampling practices and the 'correct' sampling devices based on Gy theory. Besides providing background and theory, this document gives guidance on: sampling and comminution tools, sample characterization and assessment, developing a sampling plan using a general sampling strategy, and reporting recommendations. Considerations are given to: the constitution and the degree of heterogeneity of the material being sampled, the methods used for sample collection (including what proper tools to use), what it is that the sample is supposed to represent, the mass (sample support) of the sample needed to be representative, and the bounds of what 'representative' actually means. A glossary and a comprehensive bibliography have been provided, which should be consulted for more details.