Amalgam Separators and Waste Best Management

Current estimates indicate that less than 1% of the mercury released into the environment comes from dental preparations and uses.^{1, 2} The 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 Notwithstanding, following are insights about stewardship efforts with respect to dental amalgam in the waste stream.

American National Standards Institute/American Dental Association (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

Amalgam separators remove amalgam particles from the wastewater to reduce the amount of amalgam entering the sewage system.  Amalgam separators are devices designed to capture amalgam particles from dental office wastewater through sedimentation, filtration, centrifugation, or a combination of these mechanisms.⁶  Some separators may also use ion exchange technology to remove mercury from wastewater.⁶  Whenever there is need for plumbing work or other activities that might dislodge amalgam waste adhering to the inside of the pipes, it is recommended that steps be taken to minimize potential health or environmental issues.

The Environmental Protection Agency (EPA) regulation on the use of amalgam separators was finalized⁷ and was effective as of July 14, 2017, with the date for compliance being July 14, 2020.

1. Environmental Protection Agency. 2014 National Emissions Inventory, version 2 Technical Support Document. July 2018. Accessed July 15, 2020.
2. U.S. Environmental Protection Agency. Mercury in dental amalgam. Accessed July 15, 2020.
3. Federal Register. Effluent Limitations Guidelines and Standards for the Dental Category: A Rule by the Environmental Protection Agency on 06/14/2017.  2017. Accessed July 16, 2020 
4. American National Standards Institute/American Dental Association. Procedures for Storing Dental Amalgam Waste and Requirements for Amalgam Waste Storage/Shipment Containers. Chicago, IL; 2006 (reaffirmed 2012).
5. American Dental Association. Best management practices for amalgam waste. October 2007. Accessed July 15, 2020.
6. Chou HN, Anglen J. An evaluation of amalgam separators. J Am Dent Assoc 2012;143(8):920-21.
7. ADA News. EPA publishes separator guidelines. American Dental Association December 6, 2017. Accessed July 15, 2020.

• ADA Center for Professional Success on Amalgam
• Advocacy Issues: Dental Amalgam
• ADA Statement on EPA Amalgam Regulation
• Brochure: Best Management Practices for Amalgam Waste (2007)
• Flyer:  ADA Promotes Voluntary Installation and Use of Amalgam Separators
• ADA published research on the effects of disinfectants and line cleaners on the release of mercury from amalgam
• ADA Guidelines on Amalgam Accumulations in Dental Office Plumbing (August 2005)
• ADA Professional Product Review: Evaluation of Amalgam Separators and Practical Issues for Purchasing, Installing and Maintaining Dental Amalgam Separators (2012)
• Study of Dental Amalgam in Wastewater: Summary and Full Text (2005; ADA Members-Only content. Posted here by permission of Springer Publishers. Springer retains all rights)
• ADA Library Services
• Search JADA for articles related to amalgam separators
• ADA member pricing for HealthFirst's amalgam recovery program