In this technical report, Mr. Bloomberg provides comments on behalf of Eramet Marietta to EPA on their proposed rule in the Federal Register to amend the National Emission Standards for Hazardous Air Pollutants (NESHAPs) for hazardous air pollutants (HAPs) from ferroalloys production facilities. The comments focus on the EPA’s Economic Impact Analysis of the economic impacts of the Ferroalloys NESHAP Rulemaking. The report concludes that the proposed rule would result in significant economic impacts and potential closure based on the nature of the costs and the domestic ferroalloys industry.