How do I report metals (or metalloids) hazardous air pollutants (HAP) such as chromium?

Please use only the mass of the of metal HAP component. The Chemical Abstracts Service (CAS) numbers for the metal elements can be found in Appendix B (PDF). HAPs that contain metal components and shall be reported include:

  • Antimony
  • Arsenic
  • Beryllium
  • Cadmium
  • Chromium
  • Cobalt
  • Cyanide
  • Lead
  • Manganese
  • Mercury
  • Nickel
  • Selenium


  1. A facility emits 100 pounds of strontium chromate
  2. The atomic mass for strontium chromate is 204
  3. The atomic mass of chromium is 52
  4. The amount of chromium is 52 divided by 204 which is 25.5% of the total atomic mass of strontium chromate
  5. Multiplying 100 pounds by the 0.255 yields 25.5 pounds of chromium
  6. The 25.5 pounds divided by 2,000 pounds per ton is equal to 0.013 tons of chromium with the CAS number 7440473 as the reported pollutant code

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1. Who must submit an emissions inventory report?
2. Who submits the emissions inventory report for a source that changed ownership?
3. Do I need to submit an emissions inventory if I did not operate in the previous calendar year?
4. Do I need to submit an emissions inventory if my facility shut down its operations in the previous calendar year?
5. What if some of the information pertaining to my facility is confidential?
6. Is there a fee associated with my Class II Inventory?
7. Who pays emissions inventory fees for a source that changed ownership?
8. If my facility doesn't operate all four quarters, why do the seasonal throughput percentages have to sum to 100%?
9. Why are the months listed for Seasonal Operating Percentages December to February, March to May, June to August, and September to November instead of the typical quarterly segments?
10. What should peaking plants enter for start time, hours/day, and days/week?
11. What pollutants must be reported?
12. Are there activities that are exempt from the emissions inventory?
13. Am I required to report fugitive emissions at my facility?
14. Do emissions from light duty vehicles such as security vehicles need to be included in the calculation of fugitive emissions from haul roads?
15. How do I report metals (or metalloids) hazardous air pollutants (HAP) such as chromium?
16. Which compounds are considered volatile organic compounds (VOC)?
17. What compounds are considered glycol ethers?
18. How should facilities report emissions due to malfunctions or upsets?
19. What types of particulate matter must be reported?
20. Which Particulate Matter (PM) emission factor should I use?
21. Which emission factor should I use if different factors are listed for volatile organic compounds (VOC), total organic compounds (TOC), and non-methane TOC?
22. Should stack height be measured from the ground or the top of the building?
23. Is there guidance on the acceptable accuracy of stack parameters?