Government and Regulatory


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 to 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.