By: Alfred L. Frost, III, MS, DDS
Journal of the Michigan Dental Association; February 2010; Volume 92; Number 2; page 24

The Changing Landscape of Dental Waste Management

The halcyon days of dentistry’s past, when we would mix raw mercury with metal pellets to create our amalgams and would dispose of our waste by placing it in the trash or pouring it down the drain, have now become but a fond and eco-unfriendly memory -- unless of course you’re still doing it this way.

The federal government, through the Environmental Protection Agency’s Resource Conservation and Recovery Act, regulates all solid wastes generated during the practice of dentistry. These wastes specifically include mercury, lead and silver. The EPA, as part of its regulation, provides for the individual States to enforce the law and to add additional “hazardous materials” to the enforceable list in their state if they feel it is germane to do so. Let’s discuss each of the six main waste categories and what is required with each.

Scrap amalgam: This includes any extra mix or carvings, empty capsules from pre-capsulated amalgam (the only type you should be using), extracted teeth containing amalgam, in-line disposable traps, and vacuum traps located on wet vac systems. These materials should not be discarded with regular trash or “red bag” waste, but should be collected in specially designed containers and sent for mercury recycling.

Amalgam separators: Michigan law states that all dental practices must install amalgam separators not later than Dec. 13, 2013. Exemptions regarding separator installation exist for certain specialty practices, including oral and maxillofacial surgery, oral and maxillofacial radiology, oral pathology, orthodontics, and periodontics. Once in place, the dentist is required to follow best management practices and to maintain and recycle these units according to manufacturer directions. The simplest and most economical method of compliance involves the use of canister-type units that are maintenance-free and require only annual recycling.

Silver: If your office is all-digital this will not apply to you. For those who still expose and process conventional radiographs, you must recycle all used X-ray fixer. Due to its silver thiosulfate content the fixer cannot be discharged down the drain. The easiest and most economical method here would be the use of a silver recovery unit. These are manufactured in two designs. One is suitable for automatic replenisher units and the other for use with manual units, daylight loaders and dip tanks. Generally, these should last an entire year without the need of chemical storage or costly hauling.

Lead: As with spent fixer, used lead from spent X-ray film packets and old aprons and collars requires recycling. This material is placed in specially designed containers and sent for recycling when then containers are full.

Bio-hazardous wastes: In this category are your “red bag” regulated wastes (blood-soaked items, human tissue, teeth without amalgam, etc.) and sharps (needles, scalpels, broken glass, etc.) These require placement into specially designed and labeled containers. These materials must not be accumulated in the office for more than 90 days at a time, which means shipping it out of the office four times a year. Incineration at a licensed medical waste incineration facility is the disposal method of choice.

Pharmaceutical wastes: These include partially used anesthetic carpules, medications used for sedation, IV sedation tubing, expired contents of emergency kits, etc.

Other wastes: Other wastes, thankfully, are found with diminishing frequency in dental offices. Spent gluteraldehyde, for example, must be neutralized prior to drain discharge or may be substituted with Sporox to achieve the same high level of disinfection without the problems of aldehyde sensitivity reactions or disposal. Chemical vapor sterilizer waste must be collected and hauled off-site. These and various other chemicals are being used less commonly in today’s practice.

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Frost is vice president for clinical and scientific affairs at Dental Recycling North America, Inc. (DRNA). DRNA, endorsed by the Michigan Dental Association, provides discounted pricing exclusively for MDA members. For more information, call DRNA at (800) 360-1001, ext. 17,
or visit www.drna.com.