Amalgam Separators and Waste Best Management

Key points: 

  • Dentists are encouraged to follow dental best management practices for amalgam waste handling and disposal.
  • The EPA requires amalgam separators to achieve at least a 95% removal efficiency.
  • The EPA final rule on amalgam separators was effective as of July 14, 2017, and the date for compliance was July 14, 2020.
Introduction

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.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

Amalgam Waste Best Management Practices
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
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 finalizedand was effective as of July 14, 2017, with the date for compliance being July 14, 2020.

References
  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 Resources


Last Updated: July 16, 2020

Prepared by:

Department of Scientific Information, Evidence Synthesis & Translation Research, ADA Science & Research Institute, LLC.


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