Q UALITY S YSTEMS The Good Laboratory Practice (GLP) is a quality system concerned with the organ-

5.1.1 Q UALITY S YSTEMS The Good Laboratory Practice (GLP) is a quality system concerned with the organ-

izational processes and the conditions under which nonclinical health and environ- mental safety studies are planned, performed, monitored, archived, and reported. The ISO=IEC 17025:2005 Standard, replacing the previous standards (ISO=IEC Guide25 and EN 45001), contains all the general requirements for the technical competence to carry out tests, including sampling, that laboratories have to meet if they wish to demonstrate that they operate a quality system, and are able to generate technically valid results. It covers analytical tasks performed using standard methods, nonstandard methods, and laboratory-developed methods, and incorporates all those requirements of ISO 9001and ISO 9002 that are relevant to the scope of the services that are covered by the laboratory’s quality system. The OECD GLP GLs and the ISO=IEC Standard focus on different fields of activities, but they have been developed simultaneously, and they are specifying basically the same requirements in terms of AQC.

The quality assurance (QA) program aimed at achieving the required standard of analysis. It means a defined system, including personnel, which is independent of the study conduct and designed to assure test facility management that the analyses of samples or conduction of the studies comply with the established procedures.

Measurements of any type contain a certain amount of error. This error com- ponent may be introduced when samples are collected, transported, stored, and analyzed or when data are evaluated, reported, stored, or transferred electronically. It is the responsibility of quality assurance programs to provide a framework for determining and minimizing these errors through each step of the sample collection, analysis, and data management processes. The process must ensure that we do the

right experiment as well as doing the experiment right. 8 Systems alone cannot deliver quality. Staff must be trained, involved with the tasks in such a way that

they can contribute their skills and ideas and must be provided with the necessary resources. Accreditation of the laboratory by the appropriate national accreditation scheme, which itself should conform to accepted standards, indicates that the laboratory is applying sound quality assurance principles.

The internal quality control (QC) and proficiency testing are important parts of the quality assurance program, which must also include the staff training,

* Co-operation on International Traceability in Analytical Chemistry. y International Standard Organisation.

z International Electrotechnical Commission. § Organization for Economic Co-operation and Development.

Quality Assurance 127 administrative procedures, management structure, auditing, and so on. The labora-

tory shall document its policies, systems, programs, procedures, and instructions to the extent necessary to assure the quality of the results. The system’s documentation shall be communicated to, understood by, available to, and implemented by the appropriate personnel.

The laboratory shall have quality control procedures* for monitoring the batch to batch validity, accuracy, and precision of the analyses undertaken. Meas- urement and recording requirements intended to demonstrate the performance of the analytical method in routine practice. The resulting data shall be recorded in such a way that trends are detectable and, where practicable, statistical tech- niques shall be applied for evaluating the results. This monitoring shall be planned and reviewed and may include, but not be limited to, the regular use of certified reference materials and=or internal quality control using secondary reference mater- ials; participating in interlaboratory comparison or proficiency-testing programs; performing replicate tests using the same or different methods; and retesting of

retained items. 1 The analytical methods must be thoroughly validated before use according to

recognized protocol. These methods must be carefully and fully documented, staff adequately trained in their use, and control charts should be established to ensure the procedures are under proper statistical control. Successful participation in profi- ciency test programs does not replace the establishment of within laboratory performance of the method. The performance of the method should be fit for the purpose and fulfill the quality requirements in terms of accuracy, precision, sensi- tivity, and specificity. Where possible, all reported data should be traceable to international standards by applying calibrated equipment and analytical standards with known purity certified by ISO accredited supplier.

Presently, it is definitely more economical to contract out a few samples requir- ing tests with special methodology and expertise to well-established and experienced (preferably accredited) laboratories, than to invest a lot of time, instruments, and so on to set up and maintain a validated method (and experience to apply it) for incidental samples in a laboratory.

As an external quality control, participating in proficiency-testing schemes, provides laboratories with an objective means to demonstrate their capability of producing reliable results.