Amalgam (dentistry) disposal. Dental amalgam is the largest source of mercury received by U.S. treatment plants. The U.S. Environmental Protection Agency (EPA) promulgated an effluent guidelines regulation in 2017 which prohibits most dental practices from disposing dental amalgam waste down the drain. Most dental offices in the U.S. are required to use an amalgam separator in their drain system. The separator captures the waste material, which is then recycled. The European Commission has issued a Waste Directive that classifies amalgam waste as a hazardous waste. The waste should be separated from other waste by fitting amalgam separators in all dental practices. Mercury
Amalgam (dentistry) or longer to reach a reasonably high value. At the time when the patient is dismissed from the surgery, typically some 15–20 minutes after placing the filling, the amalgam is relatively weak. Therefore, dentists need to instruct patients not to apply undue stress to their freshly placed amalgam fillings. In addition, amalgam restorations are brittle and susceptible to corrosion. The alloys are broadly classified as low-copper (5% or less copper) and high-copper alloys (13% to 30% copper). The solid particles of the alloy are either spherical or irregularly shaped microspheres of various sizes or a combination of the two. The