About considering both false negative and false-positive errors when assessing compliance and non-compliance with reference values given in compositional specifications and statutory limits

Taking account of the uncertainty in measurement is essential when making compliance decisions, but how to do it is problematic. This paper considers two types of compliance decision rule. One set of rules is that described in publications from a number of national and international bodies while the second set is one developed by this laboratory. The effect of using of the two sets of rules on the outcome of compliance decisions associated with simulated measurement data and real measurement data is evaluated. The strengths and weaknesses of the different approaches are also discussed and it is concluded that the best approach depends on the type of measurement.