P2: Dental Practices Managing Dental Amalgam

• Storage and Handling
• Best Management Practices
  
• Amalgam Separators
  
• Recycling Amalgam

Storage and Handling

Amalgam Waste Storage

• Amalgam waste should be stored in a container that is air-tight, wide-mouthed and leak proof.
• Some recyclers require contact and non-contact amalgam to be stored in separate containers.
• Labels should state the type of waste contained (for example: "Amalgam Waste for Recycling") and the date the waste was initially placed in the container.
• Container should remain tightly closed, except when adding or removing waste.
• Container should not be stored at the dental facility for more than one year from the date waste was initially placed in it.
• Check with recycling company to determine if contact amalgam needs to be disinfected.
• Never put amalgam waste in sharps containers, medical "red bag" waste containers or with regular garbage.

Amalgam Waste Handling

• Use precautions such as gloves, glasses and masks when handling amalgam waste.
• Place only amalgam waste (and used filters containing amalgam) in storage container. Do not put items used to handle the waste, such as gloves and paper towels, into the container.

Best Management Practices

Amalgam Capsules

• In order to reduce waste, keep capsules on hand in a variety of sizes.
• Store entire contents of broken or unusable capsules with amalgam waste.
• Empty capsules should also be stored and recycled with amalgam waste.
• Spills from capsules should be contained and cleaned immediately.

Amalgam Traps

• Chair-side traps prevent large amalgam particles from entering the sewer system.
• Change and clean chair-side traps as needed. Check with the equipment manufacturer to determine which cleaning agent is best. (Avoid cleaners containing bleach, which can dissolve mercury from amalgam particles and release it into the sewer.)
• Before changing the trap, the vacuum system should be flushed with approved disinfecting line solution. In order to allow the particles time to dry, lines can be disinfected at the end of the day and traps removed at the beginning of the next day.
• All visible amalgam should be removed from replaceable traps and placed in the appropriate storage containers. The trap should not be rinsed.
• Disposable traps should always be recycled with contact amalgam.
• Finer screens, such as 100 mesh traps, are more effective and trap more amalgam. However, they require more cleaning and changing.

Amalgam Filters

• Vacuum pump filters also prevent large amalgam particles from entering the sewer system.
• Filters should be replaced per the equipment manufacturer's recommendation.
• Some recycling companies only accept filters after they have been decanted. Check with the recycling company to determine if this is necessary and for instructions on decanting.
• Most recycling companies accept filters placed in containers with other amalgam waste. Some require that filters be are shipped separately. Check with the recycling company for details.

Plumbing

• Amalgam from past practices can settle at low points in the plumbing system, releasing mercury into the water for years. When having plumbing work done at the dental office, special care should be taken to capture and recycle this amalgam. Provide plumber with ADA Guidelines on Amalgam Accumulations in Dental Office Plumbing.
• Sink traps and sumps should be cleaned or replaced if you know or suspect mercury accumulation.
• Contents of the plumbing should not be spilled because they may contain mercury. They should be poured or brushed out and treated as contact amalgam.
• Once mercury has been removed, traps and sumps can either be put back or discarded.

Amalgam Separators

Size

• Manufacturer's specifications and recommendations must be used to determine proper sizing for volume and flow of dental amalgam wastewater in the office. The maximum allowable flow rate through the amalgam separator may not exceed the maximum flow rate capacity at which the separator was tested and passed in meeting ISO 11143.
• The separator should be adequately sized based on the number of chairs in the dental office. According to the ADA's Amalgam Separator Buyer's Checklist, if there are more than four chairs, a central unit should be used.
• If more than 40 amalgam-related procedures are done per week, the separator must have a large storage capacity
• There should be adequate space available in the dental office for installation, maintenance and replacement of amalgam separators. It is necessary to have enough space surrounding the unit for access to upstream piping.

Efficiency

• Amalgam separators remove more amalgam from dental wastewater than filters and traps. Therefore, by installing separators, dentists are doing more to help the environment.
• ISO 11143 requires that amalgam separators have at least 95% amalgam removal efficiency.
• Many separators can attain an efficiency of 99% amalgam removal.

Operation

• Amalgam separators should be able to treat all wastewater that comes in contact with amalgam (including water from the chairs, sinks and drains).
• When operating wet cuspidors, plumb to a separate line. If this is not possible, the separator should have a holding or surge tank.
• Amalgam separators should operate quietly and should be hands-off. Manual operations should not be necessary. The more simple the design, the better.
• Suction power should never be compromised.
• In case the separator is not operating properly and blockage occurs, the unit should have a fail-safe mechanism to protect against spills and back-up.

Cost

• The initial unit cost for an amalgam separator can range from approximately $300 to over $2,500.
• In addition to the purchase price, long term prices, such as maintenance, part replacement and possibly recycling contracts, should also be considered.

State Laws

• According to the EPA (in 2008), 11 states have laws requiring the installation and use of amalgam separators. .
• All of these states (with the exception of Maine) also require that dental offices follow the state's best management practices.
• New York and Rhode Island require 99% efficient amalgam separators. Massachusetts and Maine require 98% efficiency. The other seven states with amalgam separator laws require that it meet the ISO Standard 11143 of 95% efficiency.

General Recommendations

• Visit the ADA for a guide on purchasing, installing and operating dental amalgam separators.
• Captured amalgam should always be recycled. Some companies that sell amalgam separators will also provide recycling and it is a good idea to use such a company.
• Manufacturer's instructions should be followed when installing, operating and maintaining amalgam separators. It is best to find a company that provides both installation and maintenance on the system.
• Plumbing, electrical and septic system requirements should also be taken into consideration. Plumbing systems must be consistent with lease provisions. Existing vacuum/drain line requirements should not be constricted.

Recycling Amalgam

Choosing a Recycling Company

Dental offices have a responsibility to ensure that their wastes will be managed in a manner that protects human health and the environment. When choosing an amalgam recycling company, require the following documentation:

• That the company complies with the ANSI/ADA Specification 109: Procedures for Storing Amalgam Waste and Requirements for Amalgam Waste Storage/Shipment.
• That the company is permitted by EPA, or applicable state regulator to collect, transport and/or recycle amalgam.
• If the company that accepts your amalgam is not the actual amalgam recycler, they should provide names, addresses, and permit information for all the companies involved in handling your waste. You should also require the company to track and document the transport of the waste from when it leaves your office to its final fate (recycling).
• Visit the ADA's Directory of Dental Waste Recyclers for a list of recyclers that provide nationwide services, as well as a list of questions to compare services of recycling companies.

Shipping and record keeping

• Recycling companies should provide the proper containers for storage of amalgam. These containers should be air-tight, leak proof and wide-mouthed. They should be labeled "Amalgam Waste for Recycling", unless instructed otherwise by the recycling company.
• Containers for shipping should also be provided by the recycling company. Amalgam waste pick-up is an option provided by many recycling companies, but carriers such as the USPS, UPS and FedEx may also be used if amalgam is properly contained and meets the Department of Transportation regulations.
• When waste is picked up, the following records should be kept by the dental office for at least three years:
• Date of collection
• Name and address of the collection service
• Amount (weight) of dental amalgam collected
• Name and address of the facility where the amalgam waste will ultimately by recycled
• Certification that the mercury contained in the waste was destined for recycling.

General Recommendations

• Contact the amalgam waste recycler regarding any special requirements they may have. For example, amalgam may be mixed with bodily fluids and therefore require disinfection before recycling.
• Not all companies accept every type of amalgam waste. Contact the recycler to find out what forms of amalgam are accepted before sending waste.

(from ADA recommendations at www.ada.org/prof/resources/topics/amalgam_bmp.asp)

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