VALIDATION OF TEST METHOD

The news that BIS has validated test method CSE used to trace pesticides in soft drinks has raised more questions than it sought to answer. Validation of test methods is not an administrative or bureaucratic exercise. Validation is a scientific process by which the reliability and relevance of a test method and test results are evaluated for the purpose of supporting a specific use. A test is considered validated when its performance characteristics, advantages and limitations have been adequately determined and demonstrated for the specified purpose.

Validation has many components for which required competence is first established, documented and demonstrated. ISO/IEC 17025 provides detailed guidelines for validation of test methods. NABL is using this standard for accreditation of testing laboratories. BIS and CSE or any other testing laboratory are required to demonstrate necessary competence to carry out tests, including sampling using standard, non-standard or laboratory developed test methods, before their test findings are considered reliable and technically valid. Showing the test report to 'number of scientists' is over-simplification of a complex technical issue. Whether GC-ECD and GC-NPD tests have been validated at CSE laboratory is not clear. If this validation has been done then the question is who did this validation and whether validating agency had necessary competence for doing such validation.

Both BIS and CSE has a moral responsibility to take indian consumer in confidence by publicising details of test methods used, validation results, results of tests and whether these results are supported by inter-laboratory comparision.


S.C.Gupta
Convenor
'Better-life-for-all'