Iron and Steel Foundries: National Emissions Standards for Hazardous Air Pollutants (NESHAP)

Rule Summary

This rule sets national emission standards for hazardous air pollutants (NESHAP) for iron and steel foundries. The EPA has identified iron and steel foundries as a major source of hazardous air pollutant (HAP) emissions. These proposed standards will implement section 112(d) of the Clean Air Act (CAA) by requiring all major sources to meet HAP emissions standards reflecting application of the maximum achievable control technology (MACT).

Iron and steel foundries melt scrap, ingot, and other forms of iron and steel and pour the resulting molten metal into molds to produce shaped products. Most are operated by manufacturers of automobiles and large industrial equipment and by their suppliers.

The HAP emitted by iron and steel foundries include metal and organic compounds. For iron and steel foundries that produce low alloy metal castings, metal HAP emitted are primarily lead and manganese with smaller amounts of cadmium, chromium, and nickel. For iron and steel foundries that produce high alloy metal or stainless steel castings, metal HAP emissions of chromium and nickel can be significant. Organic HAP emissions include: acetophenone, benzene, cumene, dibenzofurans, dioxins, formaldehyde, methanol, naphthalene, phenol, pyrene, toluene, triethylamine, and xylene. Exposure to these substances has been demonstrated to cause adverse health effects, including cancer and chronic or acute disorders of the respiratory, reproductive, and central nervous systems.

EPA expects this rule to reduce air toxics from iron and steel foundries by about 580 tons per year and other pollutants by about 1,850 tons per year.