Amalgam scraps must be collected in sealed, labeled containers and sent to a licensed amalgam recycler. They should never go in the regular trash, biohazard bags, sharps containers, or down the drain. Federal law requires dental offices that place or remove amalgam to capture mercury-containing waste and keep it out of the sewer system, and the specific container you use depends on whether the scrap has touched a patient.
Contact vs. Non-Contact Amalgam Scrap
The American Dental Association divides amalgam waste into two categories, and each gets its own container. Non-contact amalgam is leftover material that was mixed but never placed in a patient’s mouth. Contact amalgam is anything that touched a patient: carving scrap collected chairside, plus material caught by chairside traps, filters, and screens.
For non-contact scrap, place pieces into a wide-mouthed, airtight container labeled “Non-Contact Amalgam Waste for Recycling.” Seal it tightly and send it to a recycler once full. For contact amalgam, the process is similar but uses a separately labeled container marked “Contact Amalgam Waste for Recycling.” If you use disposable chairside traps, drop the entire trap into this container. If your traps are reusable, empty their contents into the container and rinse the trap through the evacuation system so the rinsate passes through your amalgam separator.
Both containers need tight-fitting lids. Keeping them sealed prevents mercury vapor from escaping into the operatory air between uses.
What You Cannot Do With Amalgam Waste
Several disposal routes that might seem logical are strictly off-limits:
- Regular garbage: Amalgam in a landfill leaches mercury into soil and groundwater.
- Biohazard or red-bag containers: These are typically incinerated, which releases mercury vapor into the air.
- Sharps containers: Same incineration problem.
- Sinks, drains, or suction lines without a separator: Mercury flows directly into the public sewer system.
Dental offices contribute an estimated 8 to 14 percent of the total mercury entering wastewater treatment plants. Those plants are not designed to remove mercury, so what goes in largely passes through into rivers and waterways.
Amalgam Separators Are Federally Required
Since 2017, the EPA’s Dental Office Category rule (40 CFR Part 441) requires every dental office that places or removes amalgam to install, operate, and maintain an amalgam separator. These devices capture mercury and other metals from wastewater before it enters the sewer. The office must also avoid flushing scrap amalgam down the drain and must not use line cleaners that dissolve amalgam particles, which would allow mercury to bypass the separator.
Offices subject to the rule must submit a one-time compliance report to their local pretreatment control authority, which is usually the municipal wastewater utility. If your office doesn’t discharge amalgam wastewater into a public sewer system at all, the federal rule doesn’t apply to you, though state rules may still require certain practices.
Record-Keeping and Separator Maintenance
The separator itself needs a monthly inspection at minimum. You’re checking that all amalgam process wastewater is flowing through the device, that nothing is bypassing it, and that the retaining container isn’t full. Keep documentation of every inspection, every container replacement, every repair, and every pickup or shipment to a recycler. The rule requires you to retain these records for at least three years and make them available if inspected. That includes receipts, shipping manifests, and the manufacturer’s current operating manual for your specific separator model.
Extracted Teeth With Amalgam Fillings
Extracted teeth are normally treated as regulated medical waste, but teeth containing amalgam fillings need a different path. The CDC warns against placing them in any container destined for incineration, because burning amalgam sends mercury vapor into the air from incinerator stacks. That rules out regular garbage, sharps containers, and red bags.
Many metal recycling companies accept extracted teeth with amalgam. Contact your recycler for specific handling instructions. One additional caution: do not heat-sterilize extracted teeth that contain amalgam. Autoclaving or other heat treatment can vaporize the mercury, creating an inhalation hazard for staff.
State and Local Rules May Be Stricter
Twelve states have mandatory programs that go beyond the federal baseline: Connecticut, Louisiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New Mexico, New York, Rhode Island, Vermont, and Washington. At least 18 additional local jurisdictions have their own rules. The federal rule was designed to layer on top of these existing programs without conflicting with them, so if you’re already compliant with a stricter state program, you likely just need to file the one-time federal compliance report.
Louisiana is a notable case. Its state requirements don’t explicitly mandate amalgam separators but instead require offices to follow ADA best management practices, which have included separators since 2008. If you’re in a state without its own program, the federal rule still applies as long as your office discharges to a public sewer.
Using a Recycler
The amalgam collected in separators and scrap containers is considered hazardous waste under federal resource conservation law because of its mercury and silver content. However, most dental offices produce far less than the 100 kg per month threshold that triggers full hazardous waste generator requirements. The EPA classifies these offices as Very Small Quantity Generators, which are exempt from most of the paperwork-heavy disposal regulations. You still need to send the waste to a licensed recycler, and you should keep the shipping receipts and manifests as part of your three-year record-keeping obligation.
Several national companies specialize in dental amalgam recycling and will supply pre-labeled containers, provide prepaid shipping, and send back certificates of recycling. Your state dental association or local wastewater authority can often recommend approved recyclers in your area.