In December, the final primary lead smelter in the United States will close. The lead smelter, located in Herculaneum, Missouri, and owned and operated by the Doe Run Company, has existed in the same location since 1892.

The Herculaneum smelter is currently the only smelter in the United States which can produce lead bullion from raw lead ore that is mined nearby in Missouri’s extensive lead deposits, giving the smelter its “primary” designation. The lead bullion produced in Herculaneum is then sold to lead product producers, including ammunition manufactures for use in conventional ammunition components such as projectiles, projectile cores, and primers. Several “secondary” smelters, where lead is recycled from products such as lead acid batteries or spent ammunition components, still operate in the United States.

Doe Run made significant efforts to reduce lead emissions from the smelter, but in 2008 the federal Environmental Protection Agency issued new National Ambient Air Quality Standards for lead that were 10 times tighter than the previous standard. Given the new lead air quality standard, Doe Run made the decision to close the Herculaneum smelter.

Whatever the EPA’s motivation when creating the new lead air quality standard, increasingly restrictive regulation of lead is likely to affect the production and cost of traditional ammunition. Just this month, California Governor Jerry Brown signed into law a bill that will ban lead ammunition for all hunting in California. The Center for Biological Diversity has tried multiple times to get similar regulations at the federal level by trying, and repeatedly failing, to get the EPA to regulate conventional ammunition under the Toxic Substances Control Act.

At this time, it’s unclear if Doe Run or another company will open a new lead smelter in the United States that can meet the more stringent lead air quality standards by using more modern smelting methods. What is clear is that after the Herculaneum smelter closes its doors in December, entirely domestic manufacture of conventional ammunition, from raw ore to finished cartridge, will be impossible.

Visit NRA-ILA for for your state gun laws.