• Mitigation techniques and technologies are being implemented to reduce emissions from the category that are expected to be reflected in the inventory estimates

• Significant changes in emissions (i.e., growth or decline) from the category are expected in the future

• High uncertainty is evident for the category;

• Unexpectedly low or high emissions, or other order of magnitude discrepancies, are apparent for the category

• Major changes in the estimation methodology or data have occurred.

In many cases, the results of this qualitative approach to identifying key categories will overlap with categories already defined as key categories through the quantitative analysis.

However, the qualitative method may illuminate a few additional key categories, which should then be included in the final list of key categories. In addition, it may also identify additional reasons why a category should be treated as key, which is important information for the application of QA/QC procedures.

The application of such qualitative criteria are primarily intended to identify any additional categories that were “just under” the threshold criteria for the level assessment and not for extremely minor categories