In chromatographic tests, the disregard limit is defined as the nominal content at or below which peaks/signals are not taken into account for calculating a sum of impurities. The numerical values for the disregard limit and the reporting threshold are usually the same.

Peaks corresponding to the blank or the sample matrix can also be disregarded, as well as other peaks that the monograph explicitly states are to be disregarded.

In other words, if impurities (specified or unspecified) are above the disregard limit, they should be taken into account for the calculation of the total impurities.