How are threshold determinations made for metal-containing compounds?
Threshold quantities for metal compounds are based on the total weight of the metal compound, not just the metal portion of the metal compound. The threshold quantities are determined by adding up the total weight of all metal compounds containing the same parent metal. However, release and other waste management calculations are based solely on the weight of the parent metal portion of the metal compounds. Note that there are a few metal compounds that are separately listed and are not counted in the metal compounds categories. For example, maneb (CAS number 12427-38-2) is a manganese compound that is a separately listed chemical and is not reportable under the manganese compounds category. Additional guidance on metal compound threshold determinations can be found in Directive #5 of the Addendum to 1998 Question and Answer Document, the Toxic Release Inventory Reporting Forms and Instructions, and the TRI Guidance Documents Web site.