1. General Considerations
A quality management system (QS) for microbiological analyses establishes a quality assurance (QA) policy or program and quality control (QC) operational techniques and practices.
These are designed to
• substantiate the validity of analytical processes and data;
• ensure compliance with regulatory requirements,
• fulfill customer and project quality objectives and requirements, and
• adhere to applicable standards of accreditation or certification.
The laboratory practices in Section 9020 represent best practices for stand-alone (brick and mortar) and mobile laboratories. These practices may be required by regulations, standard-setting organizations, and laboratory certification or accreditation programs.
Each laboratory develops and documents its QS policies and objectives in a quality management plan or quality manual. The document clearly defines responsibilities and duties to ensure that the data generated are the required type, quality, and quantity.
Staff typically spend about 15% of overall laboratory time on the various aspects of an established QA program. More time may be needed for analyzing and reporting crucial analytical data (e.g., data for enforcement actions). When properly administered, balanced, and conscientiously applied, a QS optimizes data quality, identifies problems early, and increases satisfaction with analytical results without affecting laboratory productivity.
Microbiological analyses are inherently variable because they measure dynamic living organisms. Several of the QC tools available to microbiologists are different from those routinely used by chemists because many of the microbiologists’ measurements involve discrete variables rather than continuous ones. Discrete variables have only integer values; continuous variables are not limited to particular values but rather the accuracy of the measuring tool used. Therefore, different statistics and probability distributions are also used to evaluate chemical and microbiological data.