American dentists now required to use amalgam separators

US Environmental Protection Agency (EPA) promulgated a standard to reduce discharges of mercury from dental offices into Publicly Owned Treatment Works (POTWs). The Rule requires emitting dental offices to use amalgam separators and the ADA's Best Management Practices for amalgam waste.^1,2

The Final Rule became effective on 14 July 2017. New construction must comply immediately. Offices discharging amalgam without separators have three years to comply, while those in partial compliance have ten years. Required documentation includes use, installation and maintenance of amalgam separators, as well as baseline and monthly inspection records.^1,3

Dental offices are not major mercury contributors, being responsible for less than 1% of all man-made mercury released into the environment. However, dental offices are the main source of mercury (as much as 50%) discharged into POTWs. The EPA estimates 5.1 tons of mercury, as well as 5.3 tons of other metals, present in dental waste amalgam are released into POTWs annually. Most amalgam mercury (99.5%) remains as a solid,^3,4,5 even after wastewater treatment. Mercury in amalgam can also enter the environment through incineration, landfilling and wastewater sludge. Aquatic bacteria can convert any soluble amalgam mercury into methymercury, a highly toxic chemical.^1,3,4