Historical Review of Where J Flag and CLP QC Started

Oral Presentation

Prepared by G. Ward
ORELAP, 3150 NW 229th Ave Suite 100, Hillsboro, OR, 97124, United States

Contact Information: [email protected]; 503-693-4122


During the early formation of EPA's Contract Laboratory Program and the drafting of SW-846, 3rd Edition, the formulation of many of the QC terms and requirements still in use today were initiated.

This talk will cover the history behind the data qualifiers like the J flag, Quality Control such as CCV, LCS, MS/MSD, CRI, ICS, as well as Second Source, SDGs, Holding Times, SOPs, and MDLs/IDLs procedures. Also covered will be the Implementation of ICP, ICP/MS, capillary columns, EDDs, CLP forms and the first coining of the terms "legally defensible data," "data of known and documented quality," and "before and after manual integrations."