ISO/TS 18083|IDF/RM 51:2013 specifies the calculation of the approximate content of phosphorus from added phosphate salts and phosphorus containing pH-regulating agents in processed cheese products. The method is applicable to processed cheese products derived mainly from cheese varieties with a P/N ratio of 0,12 ± 0,02 and containing no ingredients in quantities substantially affecting the P/N ratio of the cheese raw material.