DIN SPEC 38402-100:2017-08

In order to protect people and the environment there are numerous legal standards that specify maximum permissible emissions. These may relate to substances, mixtures of substances, energies and pathogens. Various terms are used in the legal standards and literature for the values to be complied with (minimum or maximum values), such as limit, standard, set point, target, quality target, guideline, clearance, reference, background, precautionary, tolerance, hazard prevention, toxicity, threshold, test, maximum, intervention, action, exposure, remediation obligation, alarm value, environmental quality standard and so on. In this document, limit values are generally used in this context. The definition of limit values is based on different principles, for example scientific, medical-toxicological, technical or political. During an assessment, non-compliance with limit values results in a graduated need for action or consequences. Depending on the regulation, one or more analysis results are required in order to review compliance with a limit value. In doing so it shall be specified how the analysis values are to be determined and how the test is to be carried out. A measurement method may be specified to this end. Alternatively, the performance criteria to be met (for example, accuracy, precision, limit of quantification, etcetera) may also be specified. As measurements can be carried out continuously or in random or composite samples, the corresponding procedure for a limit value to be complied with shall be specified. Due to the fact that analytical results are in principle subject to measurement uncertainty, this measurement uncertainty shall be taken into account when assessing whether or not limit values are complied with. This document provides guidelines for checking compliance with limit values if the parameters to be determined can be regarded as at least approximately continuously quantifiable. In addition, the methods presented here can also be used in other areas such as soil and waste analysis and remediation, toxicology, pharmacy, materials science and so on. This document has been prepared by Working Group NA 119-01-03-01-04 AK "Chemometrie" ("Chemometrics") of Working Committee NA 119-01-03 AA "Wasseruntersuchung" ("Water examination") at DIN Standards Committee Water Practice (NAW).