Key points:
Current estimates indicate that less than 1% of the mercury released into the environment comes from dental preparations and uses.1, 2The majority of mercury from dentistry-related origin is in the form of elemental mercury in amalgam and not methylmercury, which is the form of mercury of particular environmental concern. After elemental mercury is released in the aquatic environment, some bacteria can transform it into methylmercury, a toxic form of mercury that can accumulate in fish and shellfish.3 The following are insights about stewardship efforts with respect to dental amalgam in the waste stream.
American National Standards Institute/福利姬视频 (ANSI/ADA) Standard No. 109 defines amalgam waste as including amalgam (scrap), chair-side trap filters containing amalgam, vacuum pump filters containing amalgam, saliva ejectors if used in dental procedures involving amalgam, used amalgam capsules, extracted teeth with amalgam restorations, and waste items that are contaminated with amalgam.4
Dental best management practices for amalgam waste handling and disposal4 include use of chair-side traps, use of amalgam separators, regular inspection and cleaning of traps, and use of appropriate commercial waste service to recycle and/or dispose of collected amalgam (Table). Compliance with the EPA final rule on amalgam separators is required.
Table. Best management practices for amalgam waste5
| Do |
Don't |
| Do use precapsulated alloys and stock a variety of capsule sizes |
Don't use bulk mercury |
| Do recycle used disposable amalgam capsules |
Don't put used disposable amalgam capsules in biohazard containers |
| Do salvage, store, and recycle non-contact (scrap) amalgam |
Don't put non-contact amalgam waste in biohazard containers, infectious waste containers (red bags), or regular garbage |
| Do salvage (contact) amalgam pieces from restorations after removal and recycle their contents |
Don't put contact amalgam waste in biohazard containers, infectious waste containers (red bags), or regular garbage |
| Do use chair-side traps, vacuum pump filters, and amalgam separators to retain amalgam and recycle their contents |
Don't rinse devices containing amalgam over drains or sinks |
| Do recycle teeth that contain amalgam restorations (Note: Ask your recycler whether extracted teeth with amalgam restorations require disinfection) |
Don't dispose of extracted teeth that contain amalgam restorations in biohazard containers, infectious waste containers (red bags), sharps containers, or regular garbage |
| Do manage amalgam waste through recycling as much as possible |
Don't flush amalgam waste down the drain or toilet |
| Do use line cleaners that minimize dissolution of amalgam |
Don't use bleach or chlorine-containing cleaners to flush wastewater lines |
In an effort to reduce the discharge of dental amalgam waste into municipal sewage treatment plants, also called publicly owned treatment works (POTW), the Environmental Protection Agency (EPA) adopted effluent rules specific to dental offices. The call for the installation of amalgam separators to reduce the discharge of amalgam into the POTWs.
The EPA regulation on amalgam separators applies to dental offices that place or remove dental amalgam regularly and discharge their waste into POTWs. The regulation does not apply to:
Under the rule, other dental practices that place or remove dental amalgam must be equipped with an amalgam separator that is compliant with either the with or the Standard (2008) or subsequent versions, achieving at least a 95% removal efficiency.
The rule became effective as of July 14, 2017. Separators installed prior to 2017 that are functioning properly can be used until 2027 at which time they would need to be updated. This grandfather rule applies to practices where ownership is transferred prior to 2027.
A One-Time Compliance Report documenting the use of a separator (or exemption due to minimal discharge of amalgam) must be filed with your area Control Authority. The Control Authority may be a local wastewater utility, a state environmental agency, or a U.S. EPA regional office. Check with your state dental board to identify the Control Authority in your area. The One-Time Compliance Report must be submitted to the Control Authority no later than or 90 days after ownership of a practice is transferred. For new offices, a One-Time Compliance Report must be submitted to the Control Authority no later than 90 days following the introduction of wastewater into a POTW.
Dental unit water lines, chair-side traps, and vacuum lines that discharge amalgam process wastewater to a POTW must not be cleaned with oxidizing or acidic cleaners, including but not limited to bleach, chlorine, iodine and peroxide that have a pH lower than 6 or greater than 8.
Last Updated: August 8, 2022
Prepared by:
Research Services and Scientific Information, 福利姬视频Library & Archives.
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