When updating the PCDD/PCDF inventory, it is necessary to review the baseline/previous inventories, due to a number of reasons:

  • The Toolkit is regularly updated (emission sources and emission factors).
  • The identification of additional sources in the updated inventory, for which information was not yet available at the time the previous inventories were conducted.
  • The improvement of the estimates of activity rates in some complex categories, requiring a review of previous inventory estimates. This is not specifically addressed in this case study.

The process to update and, when necessary, revise the inventory is essential to guarantee the comparability among results and establishing trends over time. Data quality and confidence in inventory results can be improved by site visits using a limited number of significant facilities. It is worth to include those facilities which have the potential to contribute more to the inventory, i.e. large facilities contributing to a large part of the overall production of the sector.

Finally, the process of collecting information for the inventory updating helps to identify gaps and inconsistencies in available information. This offers the opportunity for a practical analysis and a chance to improve and implement better mechanisms for collecting reliable information that may decrease the time needed in future updates and improve the quality of past estimates through revision of previous inventories to fill such gaps.