1.1 This guide provides an approach for both the calculation and the substantiation of recycled content of finished packag-ing paper and paperboard products. Amass balance approach is recommended for use by manufacturers since no physical or chemical test method is currently available to determine absolute recycled content of a finished paper product. Calcu-lations are based on time weighted average flows which are based on furnish component flow rates and consistency. Rec-ommended approaches to the calculations include by batch or by time weighted average for a specific grade or similar grades.It is not recommended that average recycle content be allocated by mathematical apportionment rather than by actual fiber content. That is, if 50 % recycled fiber is used over time that is the time weighted average. One cannot use this same data to report 50 % of the production is 100 % recycled.
