Prevent the release of mercury into the environment

By Leslie Canham, CDA, RDA

Concern about the effects of mercury in the environment has increased over the years. Mercury in the environment is bioaccumulative, which means that it can build up in fish and cause health problems in humans and other animals that eat fish. Many state health professionals recommend limiting fish consumption, especially for children and pregnant women.¹

Dental offices can be a source of hazardous mercury release in the environment. Mercury in the form of amalgam waste can be accumulated in dental offices in several ways:

• Scrap amalgam
• Contact amalgam
• Used, leaking, or unusable amalgam capsules
• Chairside traps
• Vacuum pump filters and traps
• Amalgam separators
• Extracted teeth containing amalgam

As dental professionals, we can greatly reduce the amount of mercury discharged from our offices. Understand that mercury in the form of dental amalgam is stable; however, if amalgam is disposed of in the garbage, infectious waste “red bag,” or sharps container, it may be incinerated. Incineration causes the mercury to become released in the form of vapors. Mercury vapors released into the air eventually collect in waterways, where it enters the food chain.

Fortunately, amalgam can be collected and recycled. Many sewer agencies are moving toward mandatory installation of amalgam separators, and use of amalgam Best Management Practices. To find out if this is the case in your area, contact your sewer agency.

According to the American Dental Association, Best Management Practices (BMP) are a series of amalgam waste handling and disposal practices that include, but are not limited to, initiating bulk mercury collection programs, using chairside traps, amalgam separators compliant with ISO 11143² and vacuum collection, inspecting and cleaning traps, and recycling or using a commercial waste disposal service to dispose of the amalgam. Click Best Management Practices for the publication by the American Dental Association.

Amalgam separators remove amalgam waste particles from dental office wastewater before they can be suctioned into the dental unit vacuum lines and discharged into public sewer systems. There are several types of amalgam separators — sedimentation, filtration, centrifugation, chemical removal by ion exchange, or a combination of these methods. The type of amalgam separator needed will depend on several factors. These include number of treatment chairs in an office, type of vacuum pump (wet or dry), building configuration, and other factors.

Here are simple steps that you can take to manage amalgam waste:

1. Contact an amalgam waste recycler and ask these questions:

• Will they pick up amalgam waste from your office or is there a mail-in program?
• Is an amalgam waste container provided?
• Can you combine all types of amalgam waste in one container or must it be separated?
• Are extracted teeth with amalgam accepted?
• Are the proper forms required by the EPA and state agencies provided to the dental office?

To help you locate an amalgam waste recycler, the American Dental Association has a Directory of Dental Waste Recyclers.

2. Use precapsulated amalgam.

• Limit the amount of amalgam triturated.
• Keep a variety of capsule sizes.
• Don’t throw away the empty capsules (there is still mercury present in the empty capsule).
• Place unused amalgam in the amalgam waste container.

3. Maintain traps.

• Change chairside traps regularly.
• Place chairside traps and contents in the amalgam waste container.
• Never rinse traps in the sink.
• Change vacuum pump filter traps regularly.
• Place vacuum pump filter traps in the amalgam waste container.

4. Avoid using bleach and other chlorine-containing products when flushing the vacuum lines. Studies indicate that preparations containing chlorine release more mercury from amalgam than other products.³

5. Store waste amalgam properly.

• Store amalgam in an airtight container.
• Store dry. Do not add water, bleach, oils, or other liquids to the amalgam waste.
• Label the container “Amalgam for recycling.”
• Do not place extracted teeth with amalgam in the sharps, infectious red-bag waste container, or trash.

6. Install an amalgam separator.

7. Follow Best Management Practices.

8. Always don protective attire such as utility gloves, masks, and protective eyewear when handling amalgam waste.

Protecting our environment is everyone’s responsibility. By taking a few minutes to conduct
staff training on recycling amalgam, you can be sure your team understands the Best Management Practices. This will help your office prevent the release of hazardous mercury to the environment.

Author bio
Leslie Canham is a dental speaker and consultant specializing in infection control and OSHA compliance. She has more than 36 years of experience in dentistry. Canham is the founder of Leslie Canham Seminars, providing in-office training, mock inspections, consulting, and online seminars and webinars to help the dental team navigate state and federal regulations. Reach Canham at (888) 853-7543 or Leslie Canham.

References
1. "BEST MANAGEMENT PRACTICES." American Dental Association. N.p., 2007. Web. 3 May 2011. http://www.ada.org/sections/publicResources/pdfs/topics_amalgamwaste.pdf.
2. International Standards Organization 11143:1999. Dental Equipment – Amalgam Separators.
3. Batchu H. The effect of disinfectants and line cleaners on the release of mercury from amalgam. Journal of the American Dental Association. 2006; 137(10) 1419-1425. Print.