Ozone is a gas composed of three atoms of oxygen (O3). Ozone occurs both in the Earth's upper atmosphere and at ground level. Ground level ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight.
Foundries are not significant emitters of NOx other than NOX emissions from cupolas and other combustion processes. However, it is important for the industry be informed about any new developments in ozone regulations as a result of VOC emissions from some melting and casting operations, especially where chemically-bonded sand is used for mold- and core-making.
In 2015, the ozone NAAQS was reduced to 0.070 ppm (8-hour average) from 0.075 ppm. . This revised standard is expected to have a protracted implementation schedule as a result of legislative and/or executive branch actions. Available information is provided below.
- US Chamber Multi-Association, Comments on EPA’s December 2014 Proposed Revisions to National Ambient Air Quality Standards for Ozone, March 17, 2015
- Coalition of Chambers of Commerce and Trade Associations, Proposed Ozone Standard, July 29, 2015
- Stanko, Joseph, Comments of the NAAQS Implementation Coalition on the United States Environmental Protection Agency’s “Implementation of the 2015 National Ambient Air Quality Standards for Ozone: Nonattainment Area Classifications and State Implementation Plan Requirements: Proposed Rule”, February 13, 2017
- U.S. House Bill H.R. 806, Ozone Standards Implementation Act of 2017, July 19, 2017
- American Foundry Society, Comments on the U.S. Environmental Protection Agency Evaluation of Existing Regulations Pursuant to Executive Order 13777, Enforcing the Regulatory Agenda, May, 15, 2017