ABSTRACT
Quality control performance charts or records should be maintained for each instrument.
The laboratory should prepare and follow a written QA plan (see Chapter III).
Compliance monitoring data should be made legally defensible by keeping thorough and accurate records. The QA plan and=or SOPs should describe the policies and procedures used by the facility for record retention and storage. If samples are expected to become part of a legal action, chain-of-custody procedures should be used (see Appendix A).
