How to Dispose of Dental Amalgam Waste
Mercury-containing dental amalgam waste must be captured by an amalgam separator and recycled by a licensed recycler, never flushed, trashed, or red-bagged.
What counts as dental amalgam waste
Dental amalgam waste is any waste that contains dental amalgam, a mercury-and-metal alloy. Per ANSI/ADA Standard No. 109, it includes scrap (non-contact) amalgam, used amalgam capsules, chair-side trap filters containing amalgam, vacuum pump filters containing amalgam, and extracted teeth with amalgam restorations. The hazard is the mercury and other metals it contains, not infectivity, which is why amalgam is handled as a chemical and mercury waste and recycled rather than treated as infectious red-bag waste.
Because amalgam discharged to the sewer sends mercury to publicly owned treatment works (POTWs), EPA's Dental Office Category rule at 40 CFR Part 441 requires most dental dischargers who place or remove amalgam to remove dental amalgam solids from all amalgam process wastewater using one or more amalgam separators (or an equivalent device) that achieve at least 95 percent removal efficiency and comply with ANSI/ADA Specification 108 (2009) with Technical Addendum (2011) or ISO 11143 (2008). EPA expects the rule to cut mercury discharges to POTWs by about 5.1 tons per year plus about 5.3 tons of other metals.
Step by step: containment, segregation, transport
- Capture amalgam at the source.
Use chair-side traps and a compliant amalgam separator so that all amalgam process wastewater flows through the amalgam-retaining device. Under 40 CFR 441.30, existing sources must operate a separator (or equivalent device) achieving at least 95 percent removal, compliant with ANSI/ADA Specification 108 or ISO 11143. Inspect and maintain it per the manufacturer's manual.
- Segregate amalgam waste from other waste streams.
Collect scrap (non-contact) amalgam, contact amalgam, used amalgam capsules, chair-side trap and vacuum pump filter contents, separator retention units, and extracted teeth with amalgam restorations into dedicated, labeled amalgam-recycling containers. Keep these separate from regular trash, red-bag or biohazard waste, and sharps.
- Follow the mandatory best management practices.
Per 441.30(b): waste amalgam must not be discharged to a POTW (no flushing down the drain or toilet), and dental unit water lines, chair-side traps, and vacuum lines that discharge amalgam wastewater must not be cleaned with oxidizing or acidic cleaners (including bleach, chlorine, iodine, and peroxide) with a pH lower than 6 or greater than 8, because such cleaners can dissolve mercury from the captured amalgam.
- Ship to a licensed amalgam or mercury recycler.
Send all collected amalgam waste to a suitably licensed or permitted commercial recycler. Ask the recycler whether it accepts extracted teeth with amalgam restorations and whether it holds an EPA or applicable state license. Note that amalgam captured in a separator is likely a RCRA hazardous waste due to mercury and silver content, though most dental offices fall under the Very Small Quantity Generator threshold.
- Document, report, and retain records.
Submit a one-time compliance report to your pretreatment Control Authority (a local wastewater utility, state agency, or EPA Regional Office). Maintain records for at least three years, including separator inspections, container or cartridge replacements, and the dates amalgam was picked up or shipped along with the name of the receiving licensed facility. Keep the one-time compliance report as long as the practice operates or until ownership transfers.
Container, color code, and labeling
Dental amalgam is a mercury hazard, so it is managed as a chemical and recyclable waste, not as infectious waste. Capture it with a compliant amalgam separator achieving at least 95 percent removal under 40 CFR Part 441, then recycle all collected amalgam through a suitably licensed or permitted amalgam or mercury recycler. Follow the two mandatory best management practices: do not discharge waste amalgam to the sewer (no flushing), and do not clean amalgam-wastewater lines with oxidizing or acidic cleaners such as bleach that have a pH below 6 or above 8. Do not put amalgam waste in regular trash, in biohazard or infectious-waste red bags, or in sharps containers, and do not flush it down the drain. Extracted teeth with amalgam go to the recycler; extracted teeth with no amalgam may be returned to the patient or handled as regulated medical waste.
Frequently asked questions
Can I throw dental amalgam waste in the regular trash or a red biohazard bag?
No. Per ADA guidance, do not put amalgam waste in regular garbage, biohazard or infectious-waste containers (red bags), or sharps containers, and do not flush it down the drain or toilet. The hazard is mercury, not infectivity, so amalgam goes to a licensed amalgam recycler.
What is the 40 CFR Part 441 amalgam separator requirement?
Dental dischargers who place or remove amalgam must remove dental amalgam solids from all amalgam process wastewater using one or more amalgam separators (or an equivalent device) that achieve at least 95 percent removal efficiency and comply with ANSI/ADA Specification 108 (2009) or ISO 11143 (2008). Existing sources had to comply by July 14, 2020.
How do I handle extracted teeth, with and without amalgam?
Recycle extracted teeth that contain amalgam restorations through your amalgam recycler (ask whether they require disinfection first). Extracted teeth without amalgam are not amalgam waste; they may be returned to the patient on request or handled as regulated medical waste.
Why can't I use bleach or chlorine cleaners on my vacuum lines?
Under 441.30(b)(2), dental unit water lines, chair-side traps, and vacuum lines that discharge amalgam wastewater must not be cleaned with oxidizing or acidic cleaners (including bleach, chlorine, iodine, and peroxide) with a pH below 6 or above 8, because such cleaners dissolve mercury from captured amalgam and send it to the sewer.