The estimation of Measurement Uncertainty  (MU) is not required during the validation of Initial Testing Procedures 12. b) Validation of Confirmation Procedures  for Threshold Substances  Factors to be investigated during the method validation to demonstrate that a quantitative Confirmation Procedure  for a Threshold Substance  is Fit-for-Purpose  include but are not limited to:  - Selectivity , LOI, Robustness, Carryover (see Article  5.3.5.1); - Limit  of Quantification  (LOQ): The Laboratory  shall demonstrate that a quantitative Confirmation Procedure  has an established LOQ  of no more than 50% of the Threshold  value or in accordance with the LOQ values required in relevant Technical Document (s) or Laboratory Guidelines ; - Dynamic Range: The range of the quantitative Confirmation Procedure  shall be documented from at least 50% to 200% of the Threshold  value ; - Repeatability  (sr): The quantitative  Confirmation Procedure  shall allow for the reliable repetition of the results over a short time, using a single operator, item of equipment, etc.