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Inside Dental Assisting
Mar/Apr 2012
Volume 8, Issue 2

Managing Sharps and Other Hazardous Waste in the Dental Office

Standard operating procedures and defined responsibilities are essential

Eve J. Cuny, MS

Waste materials are routinely generated during the provision of oral healthcare. Most of this waste is nonhazardous and can be managed in the same way as household waste. However, some products used in dental practices can pose a risk to humans or the environment if discarded into landfills or poured down drains. These types of waste are regulated and must therefore be managed separately. Typically, two types of regulated waste are generated as a result of dental care: regulated medical waste and hazardous chemical waste. These two types of waste each necessitate their own procedures and have different requirements for labeling, storage, disposal, and recordkeeping.

Regulatory Agencies

The US Environmental Protection Agency (EPA) regulates hazardous chemical waste. The standards set by the EPA are generally adminstered by a state or county agency. These relate to limitations on the amount of certain types of waste allowed to be discharged, the use of hazardous waste manifests, and storage, transport, and destruction of the waste.

In some cases, a hazardous material may be completely prohibited from discharge to the sanitary sewer system, such as in the case with many chemicals. In other situations, a limited amount of a hazardous material may be discharged, such as with silver, mercury, and other heavy metals. Usually, these limits are set by either the state or local authorities.

Unlike hazardous chemical waste, there are no federal standards for the management of medical waste. Instead, each state has separate requirements for how the waste is to be collected and disposed. In most cases, medical waste, including sharps, cannot be treated in the office by autoclaving and must be disposed of by a licensed medical waste treatment facility. Many treatment facilities offer services that will collect the medical waste, and sharps can be mailed to the treatment facility. When mailing sharps, carefully follow the instructions for packaging and labeling. The company providing the mailback service must be approved by the US Postal Service, and clinicians must use the packaging material supplied by the disposal facility.

Sharps and Medical Waste

Contaminated medical waste is generated as a product of healthcare services when disposable items such as gauze are contaminated with blood or other body fluids and when used sharp items such as needles and blades are discarded. The US Occupational Safety and Health Administration (OSHA) defines regulated medical waste in the Bloodborne Pathogens Standard. Regulated medical waste is liquid or semi-liquid blood or other potentially infectious materials (OPIMs), or items that would release the same if compressed. It also includes items that are caked with dried blood or OPIM that could be released during handling. Contaminated sharps and pathologic and microbiologic wastes that contain blood or OPIM are also regulated.1 All other waste, such as gloves, patient bibs, and disposable gauze that does not release blood, is not regulated but should be disposed and discarded in a manner that will not lead to accidental bare-handed contact by office or cleaning personnel.

Contaminated disposable sharps (such as used needles) comprise the majority of regulated medical waste in dental practices.2 Proper storage and labeling of regulated medical waste is one of the many provisions of the Bloodborne Pathogens Rule. Among the requirements, sharps containers must be color-coded or labeled, closable, leakproof on the sides and bottom, and placed as close as feasible to the location where the sharps are in use. OSHA requires that sharps be discarded as soon as possible after use, meaning that in most cases, the sharps container should be in the treatment room so that used needles, blades, wires, and other disposable sharps are not left until the end of the appointment to be discarded. Sharps containers should be capped when the contents reach the fill line and then discarded according to local regulations.

Sharps containers should be positioned so that they are visible and within easy horizontal reach of the person handling the disposable sharps (Figure 1). Containers should not be positioned under sinks, inside cabinets, on the backs of doors, or in high-traffic areas where a container could be dislodged accidentally.3

Some dental practices may perform procedures that result in waste products that are contaminated with blood or OPIM. If these items will release fluid blood or OPIM during handling (or dried blood that would flake), they must be discarded as regulated medical waste. Soft regulated medical waste, such as saturated gauze, cannot be placed in a sharps container but must be collected in a medical waste container that is leakproof on the sides and bottom, labeled, and closable. Often, a biohazard box lined with a red bag is used for this waste (Figure 2). These containers may be stored only for limited times in the office before they must be transported to a licensed facility for treatment. The storage time limits vary from state to state and may depend on the amount of regulated waste that an individual practice generates. Larger-quantity generators usually are allowed shorter storage time limits.

Hazardous Waste

Regulated hazardous waste includes products that are flammable, corrosive, toxic, or reactive, or pose some other risk to health or the environment. Hazardous waste can enter the environment either through solid waste sent to landfills or sanitary sewer systems when products are sent down the drain in the dental office. Hazardous material may enter the environment as a byproduct of dental procedures, such as when amalgam restorations are removed and high-speed suction lines carry the material to the wastewater stream. It may also enter the environment after use when disposing leftover or expired products that contain hazardous chemicals.

Examples in Dentistry

Numerous products that are used in dentistry may be classified as hazardous waste. Some common materials or equipment that may be regulated in various locations include X-ray processing chemicals, acid etch, disinfectants, monomers, some adhesives, X-ray film, lead foil, disinfectants, and universal waste (eg, batteries, fluorescent light tubes, computers and computer monitors, mercury-containing thermometers). Specific limits on what can be discharged down the drain or discarded into landfill are developed by either the county or state regulatory agencies and vary widely throughout the United States. It may not always be immediately obvious that a product is a hazardous waste because the manufacturer of the product does not always provide information regarding disposal. It would be virtually impossible for manufacturers to provide information that is consistently accurate because the regulations vary greatly depending upon the location of the dental office and regulatory limits for various hazardous materials can frequently change. Often, state or component dental societies maintain some general information about hazardous waste regulations and may be a useful resource for offices trying to ensure compliance.

Amalgam is probably the most well-known example of hazardous waste in the dental office. Because amalgam contains mercury, it is a regulated hazardous waste. In offices where amalgam restorations are removed, the fine particles that enter the waste stream through the high-speed evacuator are often too small to be captured in the dental unit trap. Unless other measures are taken, these small particles can become part of a sludge that makes its way to the municipal water treatment facility. Because municipalities lack the technology to remove mercury (or amalgam) from the waste water during treatment, the mercury may eventually be discharged to the rivers, lakes, and streams where it enters the food chain through fish and other aquatic life.4 Increasingly, state and regional authorities are requiring the use of amalgam separators to capture particles that are too small to be caught in the dental unit filter trap.5 In addition, the American Dental Association provides best management practices for handling amalgam with the intent of reducing amalgam to the waste stream.

Waste Reduction Strategies

Managing hazardous waste takes time and money. Violations of hazardous waste laws can result in stiff fines and, in extreme cases, incarceration. One of the most effective and economical means of managing hazardous waste is through implementation of hazardous waste reduction strategies.

Sometimes, substitution is the best approach. Substitution entails evaluating the hazardous materials that an office is using and determining whether a product of equal effectiveness without a hazardous characteristic is available. For example, if a practice is using a surface disinfectant that requires disposal as a hazardous waste, it is conceivable that an acceptable nonhazardous alternative can be found. It may also be possible to eliminate the use of some hazardous chemicals in the dental office. A switch to digital radiographs will eliminate the need to use and then discard X-ray processing chemicals.

Some offices use high-level disinfectant/chemical sterilants. In many locations, these must be handled as a hazardous waste when discarded. The items being chemically disinfected can be evaluated to determine if either heat-stable or disposable alternatives are available. If the items are noncritical (ie, contact only intact skin), high-level disinfection is unnecessary and the item can be safely processed using a less hazardous low- to intermediate-level disinfectant.

Inventory control can also reduce hazardous waste. Products with the shortest shelf life should be used first, and excess inventory beyond what will likely be used before expiration should not be ordered. Some products that are typically discarded as hazardous waste can be recycled. Dental amalgam, old crowns, and lead foil are examples of waste products that can be recycled rather than discarded.


Most dental practices are likely to generate at least one type of regulated waste, whether it is contaminated sharps, chemical waste, or blood and tissue. It is important to understand that regulations regarding the handling, storage, and disposal of waste can vary a great deal from state to state. The local regulatory agency will be the best source of information regarding specific requirements in a given location. Written standard operating procedures based on local regulatory requirements will help everyone ensure and maintain compliance. It is also useful to have clearly defined responsibilities regarding who in the office is responsible for regulated waste management.


1. Occupational exposure to bloodborne pathogens; needlestick and other sharps injuries; final rule. Occupational Safety and Health Administration (OSHA), Department of Labor. Final rule; request for comment on the Information Collection (Paperwork) Requirements. Fed Regist. 2001;66(12):5318-5325.

2. Miller CH, Palenik CJ. Infection Control and Management of Hazardous Materials for the Dental Team. 4th ed. St. Louis, MI: Mosby Elsevier; 217-223.

3. National Institute for Occupational Safety and Health, US Department of Health and Human Services, Public Health Services, Centers for Disease Control and Prevention. Selecting, Evaluating, and Using Sharps Disposal Containers. Atlanta, GA: 1998. DHHS Publication No. 97-111.

4. Chin G, Chong J, Kluczewska A, Lau A, Gorjy S, Tennant M. The environmental effects of dental amalgam. Aus Dent J. 2000;45(4):246-249.

5. McManus KR, Fan PL. Purchasing, installing and operating dental amalgam separators: practical issues. J Am Dent Assoc. 2003;134(8):1054-1065.

About the Author

Eve J. Cuny, MS
Assistant Professor
Dental Practice Director
Environmental Health and Safety
University of the Pacific
Arthur A. Dugoni School of Dentistry
San Francisco, California

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