Overview
Types of amalgam waste
Steps for recycling amalgam
Best management practices for amalgam waste
Additional links and resources

Overview
The dental profession has always emphasized preventive care. Now, this spirit of prevention needs to extend to preventing the release of amalgam to the environment.

At dental offices, vacuum systems discharge amalgam to the sewerage system when dentists place or remove amalgam fillings. Amalgam is typically 50 percent mercury, by weight. Mercury pollution has caused the Wisconsin Department of Natural Resources (DNR) to issue a statewide fish consumption advisory.

To address mercury in wastewater, the DNR requires sewage treatment facilities to implement a mercury minimization program. A primary element of this program is reducing the amount of amalgam discharged by dental offices.

Amalgam is an efficient and effective restorative material. Dentists will continue to use it in the foreseeable future, although its use continues to gradually decline. Even if dentists completely stopped using amalgam for new fillings, the removal of old amalgam will continue to generate amalgam waste.

In response to the environmental issues related to mercury, the WDA has identified best management practices for amalgam. While important, best management practices alone are not sufficient to minimize discharges. Amalgam separators are available from several suppliers and are able to decrease amalgam in wastewater by 95 percent or more.

• Read about how to recycle amalgam and choose a separator for your office 

Types of amalgam waste

• Non-contact amalgam (scrap) is excess mix leftover at the end of a dental procedure. Many recyclers will pay for this clean up.
• Contact amalgam is amalgam that has been in contact with the patient. Examples are extracted teeth with amalgam restorations or amalgam captured by chair-side traps, filters or screens.
• Chair-side traps capture amalgam waste during amalgam placement or removal procedures. (Traps from dental units dedicated strictly to hygiene may be placed in with regular garbage.)
• Vacuum pump filters or traps contain amalgam sludge and water. Some recyclers will accept whole filters. Others will require special handling of this material.
• Amalgam sludge is the mixture of liquid and solid material cleaned up from vacuum pump filters or other amalgam capture devices.
• Empty amalgam capsules are the containers leftover from precapsulated dental amalgam.

1. Use universal precautions such as gloves, masks and protective eyewear when handling amalgam waste.
2. Contact an amalgam waste recycler about any special requirements for collecting, storing and transporting amalgam waste.
3. Store amalgam waste in a covered plastic container labeled "Amalgam for Recycling", or as directed by your recycler.
   Consider keeping different types of amalgam wastes in separate containers - talk to your recycler about any advantages.

Best management practices for amalgam waste

*Confirm with your recycler whether it accepts extracted teeth. Disinfect extracted teeth by storing them in an airtight container with a solution of glutaraldehyde or 10 percent formalin until they are removed for recycling with your other amalgam waste. 

Amalgam capsules

1. Stock amalgam capsules in a variety of sizes
2. After mixing amalgam, place the empty capsules in a wide-mouthed, airtight, plastic container that is labeled Amalgam Capsule Waste for Recycling*
3. Place any non-empty capsules into this container
4. Ensure that the container is tightly sealed at all times
5. When the container is full, send it to a recycler

Non-contact (scrap) amalgam

1. Place non-contact (scrap) amalgam into a widemouthed, airtight, plastic container that is labeled Non-contact Amalgam Waste for Recycling*
2. Ensure that the container is tightly sealed at all times
3. When the container is full, send it to a recycler

Disposable chair-side traps

1. Remove the trap and place it into a wide-mouthed, airtight, plastic container labeled Contact Amalgam Waste for Recycling*
2. Ensure that the container is tightly sealed at all times
3. When the container is full, send it to a recycler
4. If a chair is strictly dedicated to hygiene, then place the trap into the regular garbage

Reusable chair-side traps

1. Remove the trap and empty the contents into a widemouthed, airtight, plastic container labeled Contact Amalgam Waste for Recycling*
2. Ensure that the container is tightly sealed at all times
3. When the container is full, send it to a recycler
4. Do NOT rinse the trap under running water

Vacuum pump filters

1. Obtain instructions and schedule for filter replacement from the manufacturer
2. Change the filter according to the recommended schedule
3. Obtain instructions for handling the used filter from your recycler
4. If you are required to decant water from the filter before recycling, pour the water into a tray or other container that can catch any spills and pour very carefully to avoid losing any amalgam.

Line cleaners

Use line cleaners that do NOT include bleach or other chlorine compounds.

Disinfection

Disinfecting amalgam waste for recycling is unnecessary, except for extracted teeth that contain amalgam restorations. For disinfection, use glutaraldehyde or 10 percent formalin, rather than bleach. Bleach dissolves amalgam and releases mercury. Use bleach only if your recycler accepts the disinfectant solution along with the amalgam waste.

*Some recyclers allow you to place all amalgam waste, including capsules, non-contact amalgam, contact amalgam, traps, filters, and teeth into the same container. If so, you may use one container labeled Amalgam Waste for Recycling. Follow your recycler’s instructions for packaging and shipping amalgam waste.

• Department of Natural Resources (DNR)
  • Rules and regulations on small generators of infectious waste
    • Medical waste information
    • Pharmaceutical waste information
    • Waste program publications
  • Practice GreenHealth (information coming soon)
    
  • DNR 526 Administrative Code on medical waste rules and regulations

• American Medical Association
  • Summary of how mercury is processed and excreted by the body
• Health Care Environmental Resource Center

Amalgam in the news

Since 1999, the WDA has partnered with the Wisconsin DNR, University of Wisconsin Extension and local sewerage districts to provide all licensed dentists in the state with recommended recycling practices for amalgam scrap and dental office waste. The WDA believes it is in the best interest of the dental profession, dental patients and society to be good stewards of the environment and promote Best Management Practices for recycling dental amalgam waste from dental offices; the association continually works to communicate this message to members and the media.

The following are links to recent media coverage regarding dental amalgam separator mandates: 

• Milwaukee Journal-Sentinel: Dentists filtering out mercury
• Milwaukee Journal-Sentinel: Editorial: Get the mercury out