City of Dayton Industrial Pretreatment Program MERCURY INFORMATION FOR DENTISTS

The City of Dayton Industrial Pretreatment Program strives to prevent the release of mercury into the sanitary sewer system. There is a concern that dental amalgam bonded with mercury may enter the sanitary sewer, travel to the wastewater treatment plant, and pass through the treatment plant into the Great Miami River or contaminate the plant's biosolids that are applied to farm fields. Mercury can also contaminate the environment via various other disposal methods. The cumulative effect of dentists' small amounts of pollutants can have a large impact on the environment.

The following guidelines for dental offices are recommended by the Ohio Dental Association to reduce the release of mercury to the environment.

• Use pre-capsulated dental amalgam and eliminate the use of bulk mercury.
• Use alternative materials to amalgam in cases where they are appropriate, ethical and economically feasible.
• Never place used or excess amalgam down the drain.
• Prevent elemental mercury from being picked up by the central suction and or not pour elemental mercury down any sink or drain.
• Recycle the amalgam captured in traps or filters and scrap amalgam by a qualified refiner and/or recycler. Do not dispose of the amalgam down the drain.
• Capture amalgam particles on screens or in traps and collect and store all used and excess amalgam (i.e., scrap amalgam) for recycling by a qualified refiner and/or recycler.
• When removing existing amalgam restorations, use a trap or inline filter on the high volume suction and filters on the vacuum system.
• Collect all excess amalgam generated in the placement of amalgam restorations with gauze.
• Larger particles should be recycled and gauzes placed in solid waste which is not incinerated.
• Store the collected amalgam waste under a small amount of radiographic fixer solution in a tightly closed container labeled: "Waste Amalgam". The fixer should then be decanted off and the amalgam blotted dry with a paper towel before the waste amalgam is sent to a recycler. Fixer solution containing silver should not enter the office's wastewater.
• All materials that have the potential to contain amalgam particles to small for recycling, such as gauze or paper towels should be disposed of via the methods of solid waste that is not incinerated.
• Dispose of amalgam in spittoon and sink traps as solid waste. Do not rinse it down the sewer lines.
• Collect used amalgam capsules in a covered container and dispose with the office's other solid waste. (Used amalgam capsules have been determined to be nonhazardous.)
• Make small amounts of elemental mercury into amalgam by reacting it with alloy which may then be added to the scrap amalgam jar for recycling.
• Keep clean and mixed amalgam separate to aid in ease of recycling.
• Use a strong sealed, suitable container and a common carrier (e.g., UPS, Federal Express, etc.) to ship waste amalgam to a recycler.
• Either mail amalgam scrap directly to a mercury reclamation company or hire a local broker to collect, package and ship the amalgam. Recycle amalgam until the use of systems to treat rinse waters contaminated with old amalgam that is too fine to be caught in traps or on screens becomes feasible.
• Use disposable traps whenever possible over reusable traps.
• If reusable traps are used, then do not clean them under running water or discharge the trapped amalgam into the wastewater. (Certain manufacturers make a dental unit for the market that has a system to collect amalgam from the water in the unit beyond the standard amalgam trap.)
• Amalgam traps should be changed weekly or more frequently if needed, or as recommended by the manufacturer of your equipment.
• Secondary vacuum pump filters should be changed periodically in accordance with the manufacturer's recommendations.
• Maintain a mercury spill kit in the office. Absorbent from the clean-up of mercury spills are accepted by some mercury recyclers. Contact your mercury recycler for information.
• Contaminated elemental mercury from spills and absorbents from cleaning up mercury spills should be managed as hazardous waste with proper labeling, storage, manifesting and shipping.
• Instruct all staff members in the proper collection, storage, disposal and handling of amalgam.

Contact the Ohio Dental Association at (614) 486-2700 or the City of Dayton Industrial Pretreatment Program at (937) 333-1501 for more information.