Every certified and accredited laboratory follows validated test procedures and refers to them as Standard Test Procedures or STP’s. Such procedures are based on methods taken from sources such as textbooks, reference journals, methods prescribed in standards such as ASTM, APHA, EPA, AOAC, USP, BP, IP, JP, EP and national standard bodies of different countries. At times laboratories also resort to client specified methods whose validity requires to be established before adoption.
Methods published in internationally reputed references are validated and can be adopted with confidence. At time of reporting the results it is essential to make reference to the source of the method so that if the product is retested anywhere the results should conform provided same specified conditions are maintained during the analysis.
It is important that any of the prescribed conditions are not altered to suit individual convenience. Several steps have been recommended to prevent any method modifications. However, under some unavoidable circumstances due to non availability of reagents or to save time some changes are permitted but the changes need to be validated by a person who is authorized by the laboratory management. The authorized person makes the necessary change in the method and authenticates the change with his or her signature and date. No other person (s) in the laboratory can make changes in standard test procedures.
It becomes critical to follow methods laid down in the standard test procedures without any deviations. Now the question arises as to how to prevent unauthorized alterations in the established methods. Some suggestions are offered here
- Keep both hard copy and soft copy record of standard test procedures for cross-reference. The soft copies should be password protected and access should be limited by the quality assurance manager
- Complete audit trail of the analysis procedures adopted should be available to the laboratory management through laboratory information management systems
- Installation of light or audible alarms to warn if any deviations are detected in set test procedures
- The analyst should be made to certify in his laboratory notebook record that none of the specified conditions has been altered apart from circumstances when due authorization has been provided
Standard test procedures are sacrosanct documents and no unauthorized changes are permitted..Punitive action should be imposed on any entity or individual for carrying out unauthorized test procedures.