Chain-of-custody procedures are a necessary element in a program to assure one's ability to support data and conclusions adequately in a legal or regulatory situation, but custody documentation alone is not sufficient. A complete data defensibility scheme should be followed.

In applying the sample chain-of-custody procedures in this guide, it is assumed that all of the other elements of data defensibility have been applied, if applicable.

1.1 This guide contains a comprehensive discussion of potential requirements for a sample chain-of-custody program and describes the procedures involved in sample chain-of-custody. The purpose of these procedures is to provide accountability for and documentation of sample integrity from the time samples are collected until sample disposal.

1.2 These procedures are intended to document sample possession during each stage of a sample's life cycle, that is, during collection, shipment, storage, and the process of analysis.

1.3 Sample chain-of-custody is just one aspect of the larger issue of data defensibility (see 3.2.2 and Appendix X1).

1.4 A sufficient chain-of-custody process, that is, one that provides sufficient evidence of sample integrity in a legal or regulatory setting, is situationally dependent. The procedures presented in this guide are generally considered sufficient to assure legal defensibility of sample integrity. In a given situation, less stringent measures may be adequate. It is the responsibility of the users of this guide to determine their exact needs. Legal counsel may be needed to make this determination.

1.5 Because there is no definitive program that guarantees legal defensibility of data integrity in any given situation, this guide provides a description and discussion of a comprehensive list of possible elements of a chain-of-custody program, all of which have been employed in actual programs but are given as options for the development of a specific chain-of-custody program. In addition, within particular chain-of-custody elements, this guide proscribes certain activities to assure that if these options are chosen, they will be implemented properly.

1.6 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.