Aug. 25 — The Environmental Protection Agency is banning exports of five mercury compounds effective Jan. 1, 2020.

The five compounds, listed in an EPA notice to be published in the Aug. 26 Federal Register, are mercury (I) chloride, also known as calomel; mercury (II) oxide; mercury (II) sulfate; mercury (II) nitrate; and cinnabar, also known as mercury sulphide.

Mercury (I) chloride, produced in volumes of about 25 metric tons annually, was the highest volume mercury compound generated in the U.S., the EPA told Congress in a 2009 report.

This particular mercury compound is a common product in wastes generated from air pollution controls, refining needed to extract zinc, gold and copper mining industries and the production of chlorine gas from brine by the chlor-alkali industry, the EPA said. Mercury (I) chloride is exported for several reasons, including it can easily be converted to elemental mercury, EPA said in “Potential Export of Mercury Compounds From the United States for Conversion to Elemental Mercury,”

The agency banned the five mercury compounds to comply with changes Congress made to the Toxic Substances Control Act through the Frank R. Lautenberg Chemical Safety for the 21st Century Act (Pub. L. No. 114-182). The amendments, which became law June 22, expanded a 2013 ban on the export of elemental mercury that Congress imposed through the Mercury Export Ban Act of 2008 (Pub. L. No. 110-414).

All five mercury compounds banned by the Lautenberg Act were discussed in the 2009 report the EPA provided to Congress.

Ban Prompted by Health Concerns

Elemental mercury is a global concern, because it can be transformed by the environment and industrial processing into methyl mercury, a neurotoxin that builds up in the food chain. People exposed to high levels of methyl mercury may experience problems such as loss of peripheral vision, impaired movement and muscle weakness, according to an EPA website. When elemental mercury reacts with another substance it can form mercury compounds. These compounds, however, can be converted through chemical, heat and other processes back into metallic mercury, giving them a market value, the EPA’s 2009 report said. EPA’s report provided details on 12 mercury compounds made as specialty chemicals or occurring as waste or by-products of industrial processing. The 12 compounds could be exported for conversion into elemental mercury, the agency said. Only mercury (I) chloride was produced in a significant quantity, but that could change as a result of the ban on elemental mercury exports, EPA said in 2009.

The top 14 facilities that reported disposing or otherwise releasing mercury compounds to the EPA’s 2014 Toxics Release Inventory were all mining companies. The 15th top generator was Clean Harbors in Reidsville, N.C., a waste treatment and disposal company.

The sole U.S. manufacturer of mercury (I) chloride was Bethlehem Apparatus Co. Inc. in 2011, the most recent year for which chemical production volume data are available from the agency. Bethlehem Apparatus, a waste treatment company specializing in mercury recovery, recycling and retirement, produced and imported 580,750 pounds of the mercury compound that year.