Led by IAOMT (the International Academy of Oral Medicine and Toxicology), a group of plaintiffs filed suit in federal district court against the US Food and Drug Administration (FDA) Commissioner and the Health & Human Services Secretary. Issues to be litigated include whether amalgam is deemed an implant, which would require proof of safety from manufacturers, and whether the same toxicity labeling requirements that manufacturers must provide to dentists should also go to patients. The petitions also cover a wealth of new scientific evidence on the health risks of amalgam, particularly to fetuses, children, and individuals with genetic susceptibilities.
The FDA issued its “final amalgam rule” in 2009, which was challenged via legal petitions to the agency. In January 2015, the agency denied all petitions and upheld its longstanding position that mercury dental amalgam is safe, at which point the plaintiffs file the lawsuit.
Note that in its 2009 amalgam rule (1), the FDA acknowledges that people with an above-average amount of amalgam will exceed the federal safety standards set by the US Environmental Protection Agency (called the Reference Concentration, set in 1995) and the Agency for Toxic Substances and Disease Registry (called the Minimum Risk Level, set in 1999) for chronic exposure to mercury vapor. The FDA claims these safety standards have uncertainty factors that provide a margin of safety, so it's not a problem. But regulatory uncertainty factors are designed to cover biological uncertainties, not excessive exposures. Furthermore, the California Environmental Protection Agency's standard, set in 2008, is ten times stricter than either of the federal standards, which means that most people with any amount of amalgam will exceed the CalEPA standard for chronic exposure to mercury vapor.
(1) Reference for FDA 2009 amalgam rule: FDA (US Food and Drug Administration) Dental devices: classification of dental amalgam, reclassification of dental mercury, designation of special controls for dental amalgam, mercury, and amalgam alloy. Fed Regist. 2009;74(148):38686–38714.