OW-2003-0074 EPA DOCKET SECTION 2.2.2 

DCN 00144 10/07/1998 

A New Prescription: Pollution Prevention 

Strategies for the Health Care Industry 

Wednesday October 7, 1998 

Boston University Corporate Education Center 

Tyngsborough, Massachusetts 

Proceedings 

Section 4: Dental Facilities 

Section 4: Dental Facilities 

Cynthia Welland Balogh and Dr. Paul Rubin, 

Removal of Mercury from Dental Amalgam Wastewater 

PaAicia White, Dental Office Waste Management: 

Safeq and regulatory Compliance Issues 

2 

31 

1 
Cynthia Welland BaIogh 

King County 

Local Hazardous Waste Mhagement Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Removal of Mercury from Dental Amalgam Wastewater 

Abstract 

Dentists, when either placing new or removing old "silver" fillings generate a considerable amount 

of waste amalgam. This may be in the form of chunks, small grindings, or slurry of fine grindings 

water. Most of this is vacuumed from the patients' mouths and eventually sent down the drain into 

the office wastewater. 

Municipalities, including King County, have found that a significant percentage of mercury 

discharged to the sewer systems originates from dental office effluent. This amalgam wastewater 

exceeds King County sewer discharge limitations for mercury by three to four orders of 

magnitude. 

Technological source control solutions do exist and are available to dental offices. However, there 

are concerns about the effectiveness, ease of use and cost of these devices. Overcoming these and 

other barriers are essential to creating new pollution prevention behaviors that keep dental 

mercury from the municipal waste streams and reroutes it to reclamation. 

This paper evaluates these concerns from the viewpoint of both local government technical 

assistance providers and a practicing dentist. Practical aspects of choosing to remove and reclaim 

mercury as well as selecting and using these devices will be presented. 

Devices available to dentists range in their effectiveness and cost. This paper evaluates methods 

of treating dental wastewater to separate amalgam particulate from the liquid fraction of the 

wastewater. The metals removal capacity of commercially available equipment from two 

manufacturers was investigated. We also designed, built and demonstrated metals removal 

capacity of a simple, inexpensive settling system. In addition to technological issues, behavior 

change principles are being applied to outreach efforts. Data from this study are being used to 

help determine best management practices for dental amalgam wastewater. 

All three pieces of equipment tested show one to four orders of magnitude decrease in mercury 

concentration and loading after treatment. Removal rates average 95-99% depending on 

equipment used. In the case of the commercial equipment, our data verifies manufacturer's claims 

for removal rates of around 99%. For our own piece of equipment, we see that a simple, 

inexpensive settling chamber can achieve removal rates in the 90-95% range and retain that ability 

over an eight month testing period. 

2 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Some of the criteria for evaluating the suitability of a system include: effectiveness, simplicity of 

operation and design, level of handling of waste material required of office personnel, "'fail-safe" 

mechanisms designed to avoid accidental spillage, system for handling proper recycling of 

material, and cost. While not all barriers to preventing mercury pollution have been over come, 

we have begun to address major concerns. Systems are in place in King County for proper 

collecting, transporting and recycling the mercury waste. Mercury removal from amalgam 

wastewater is recommended before discharge to the King County Metro sewerage system. We 

are seeking voluntary compliance from the dental community. 

Introduction 

In the past twenty-five years, sewer utility pretreatment programs have successfully addressed 

discharge from large generators, (significant industrial users -- SIUs), to the sewer system. These 

industries are regulated, permitted and monitored. Currently about 15% of the pollutants to the 

sewer can be attributed to the big generators. The remaining 85% is from households, small 

businesses (conditionally exempt small quantity generators CESQGs), and non-point sources, 

such as stormwater (Galvin, 199 1). 

Programs, such as King County Local Hazardous Waste Management Program in Washington 

State, have been developed to address the household and small business hazardous wastestream. 

Like other pollution prevention and source control programs, our purpose is to assure reduction 

of hazardous materials going into the municipal wastestream, to reduce the hazardous materials 

discharged to the environment through landfills, and sewage effluent and biosolids. Whether 

biosolids go into land application, as in King County, or are incinerated, source control is 

necessary to prevent hazardous material from accumulating and dispersing through the soil, water 

or air. 

This program works with many industry types to develop best management practices, provide on 

site consultations and assist businesses in reducing hazardous waste. In addition to the dental 

profession, some of these are print shops, photo processors, automotive repair, auto-body shops, 

dry cleaners, machine shops and marinas. 

Why Dental Waste? 

Why were we concerned with dentists? Initially, King County was required by Washington 

Department of Ecology to prioritize the elimination of occasional spikes in the concentration of 

mercury going to King County's two main treatment plants. Other considerations were the 

presence of metals, such as mercury and silver, in wastewater treatment byproducts, including 

biosolids for agricultural use and effluent for non-potable water reuse programs. Source control 

of contaminants -- preventing metals and other possible pollutants from entering the sanitary 

sewer system in the fKst place - is a priority in US Environment Protection Agency, Washington 

3 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Department of Ecology and King County policies (The federal Clean Water Act; Washington 

State Water Pollution Control Law; Washington State Hazardous Waste Reduction Act; King 

County Ordinance No. 11034). 

Thermometers, barometers, switches, fluorescent tubes, mercury boilers, manufacture of mirrors, 

dental amalgams, latex paint, pesticides and the electrical and instrument industries are among the 

potential sources of mercury (The Merck Index, 1989). In the King County service area there 

were no permitted significant industrial users (SIUs) generating significant levels of mercury. 

Industrial laundries, which may use limited amounts of mercury as a biocide, are regulated 

through pretreatment permits. All permitted discharges are restricted to a mercury limit of .2 

parts per million. Mercury as a biocide in paints has been largely phased out and a review of 

studies on potential household product contributions did not indicate significant sources of 

mercury from this sector (Galvin, 1991; Rourke, 1991; Dickey, 1990-91; Jenkins and Russell, 

1990; and Gurnham et al., 1979). Of the remaining sources, dental offices appeared to be the most 

likely potential source of mercury in the publicly owned treatment works. 

Of the several hazardous wastestreams discharged from dental offices, we have focused this paper 

on amalgam wastewater, and, in particular, mercury. Although the other metals are of concern, 

mercury is present in the highest concentrations, is most toxic and has the lowest discharge limits 

(in King County). 

Mercury Cycle In Dentistry 

How does mercury from dental amalgam actually get into the environment? The dental industry 

consumes perhaps 100T of Hg annually, though that figure is diminishing. It's made into 

amalgam in the dental office. Then a number of things can happen that lead to it entering the 

environment [Figure 11. Excess mixed amalgam that is not actually used in a filling or is carved 

away should be saved and recycled by the dentist. Some, perhaps, ignore this, and it ends up in 

the trash and eventually a landfill or incinerator. Hopefully that doesn't happen very often. 

Extracted teeth with amalgam fillings in them end up in trash or medical waste - again, landfill or 

incineration. Crematoria have been shown to produce a significant amount of mercury vapor 

from incinerated remains. But the most significant avenue that we're talking about at this 

conference happens when amalgam fillings are placed or removed and particles, chunks, dust, or 

slurry get vacuumed up by the chairside dental vacuum system. Bigger chunks are caught in a 

chairside trap, and presumably this trap gets periodically cleaned out and the pieces saved and 

Iater recycled. Any of you who are dentists know, however, that the dental staff often may take 

the easy way and simply throw this in the trash or wash it out in the sink - down the drain. Most 

of what is vacuumed up is in smaller particles or slurry, which passes right through the chairside 

traps and heads for the office wastestream. This is the part we're particularly interested in today. 

How much is it, really, and how can it be stopped? 

4 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Figwe 1. Dental Amalgam Wastestream Schematic 

5 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

How Much Mercury? 

In 1990, when we began this project, very little was known about dental waste. To appropriately 

address this waste, we needed to quantify and characterize it. We sampled the wastewater leaving 

the dental chair, and surveyed dentists to help determine quantities and types of wastes. Dental 

amalgam is made up of about 40-50% mercury, 25% silver and the rest is copper, zinc and tin. 

The results of sampling and surveying showed mercury concentrations of 100 - 2000 mg/L. The 

two long lines on the left side of the graph show the mean and standard deviation of mercury in 

untreated wastewater from dental operatories. [Figure 2.1 This exceeds our 0.2 mg/L local 

mercury limit by 500 to 10,000 times. The portion of the mercury to the King County sewerage 

system from dentists was conservatively calculated at about 14% or 52 pounds per year. 

(Welland, 1991) 

Other sewer districts have done similar studies. Minneapolis St. Paul found that an even greater 

proportion of mercury to the treatment plants, 76-80%, is from dentists. (Berglund, 1998). 

Differences in these results may stem fi-om such factors as other sources of mercury, slightly 

different sampling methods, variability of samples, analytical diffrculties and quite conservative 

assumptions on our part. 

6 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Acadaemy of Oral Medicine and Toxicology 

Seattle, Washington 

Figure 2 

Mercury in Dental Wastewater 

Loading to Sewer in mg/day 

1025 

975 

925 

875 

825 

775 

725 

675 

625 

575 

525 

475 

425 

375 

325 

275 

225 

175 

125 

75 

25 

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-- 

-- 

-- 

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-- 

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-- 

-- 

-- 

-- 

UNTREATED Samples Treated Samples 

I1006 

J 

I575 

n = 10 

1 

Mean and one standard 

deviation indicated Mean +/- Standard Deviation 

Centrifuge I= .37 +/- .3 (n = 13) 

Centrifuge 2= .81 +/- 1.1 (n = IO) 

Settling/Filter= -31 +/- .35 (n = 8) 

Composited from 30 samples l7G" 

Simple Settling= 25 +/- 19 (n = 3) 

' 415 

TREATED 

-25 

Office 1 Ofice 2 Centrif 1 Centrif2 SetlFilt Simple 

% Rem ova 199.9 99.8 99.9 96 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Approach 

Cooperation 

From the beginning of this project we have worked with the local dental community. In 1990, 

we established an advisory board to explore dental waste issues and to help with a 

characterization study. We have continued with many joint meetings, waste management articles 

in the dental journal, talks and paper co-presented and joint development of best management 

practices (BMP’s). Cooperation on waste management issues and outreach have been key. 

Voluntary Comdiance versus Formal Rulemaking 

A local Hazardous Waste Disposal Rule for Dentists was proposed in October 1994. This rule 

would have required all area dentists who discharge to the King County POTW to install amalgam 

wastewater pretreatment units. During the public comment period the local dental community 

articulated their concern about further regulation of dental office waste disposal practices? citing 

such issues as costs, newly developing products and services, and unsubstantiated environmental 

damage. In addition, the local dental community expressed a willingness to work voluntarily 

toward reduction of their contribution of hazardous substances to the waste stream. 

Instead of promulgating a rule for dentists, King County developed a program for working 

cooperatively with the dental community. 

compliance, based on the expectation that this voluntary approach continues to be embraced by 

the local dental community and our agency. 

King County has three long-term goals for 

* First, institutionalization of waste management and reduction techniques in all dental 

practices, including reclamation of mercury and silver resources from amalgam wastes and xray fixer. 

Second, the inclusion of information about dental waste management and reduction in all 

formal training programs for dental professionals in this geographic area. 

Third, to document a measurable decrease in the amount of metals discharged to the sewer 

system from dental offices in King County. 

* 

* 

!Ling County and the Seattle-King County Dental Society have established an open, responsive 

and reasonable working relationship that has contributed to the success thus far of this voluntary 

approach to waste management by dental offices in our area. Although interest is increasing, 

voluntary compliance has been slow. Approximately 1% of King County’s 1500 dentists have 

installed amalgam separation devices. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Overcoming Obstacles 

We have encountered many obstacles or barriers while moving toward better management of 

wastes fi-om dental offices. We have also seen a tremendous increase in interest and solutions to 

difficult issues. Issues include perception of problem, costs, technology and service availability. 

Acknowledging there is problem depends on having reliable information about the waste and 

about regulations. It also depends on being ready to address the problem areas. Characterizing 

dental waste showed both agencies and dentists how much mercury is in dental amalgam 

wastewater. Although philosophical approaches to protection of the environment vary, and 

questions have been posed about what environmental damage is being done, a great many dentists 

are concerned about our environment and about doing what's right. The realization is growing 

that region by region, sector by sector, everyone is being called on to eliminate or reduce 

hazardous wastes. It is this attitude, that we all have a part to play, and the desire to be part of 

the solution, that overcomes the perception, common to every regulated business, of being over 

regulated, of being picked upon. Although some dentists may personally have no problem 

discharging amalgam waste, many are recognizing the problem and want to individually, and as a 

profession, demonstrate a pro-active response. 

Responsible hazardous waste management is being noticed. A King County recognition program, 

EnviroStars, provides recognition to businesses for their efforts to protect the environment. 

Currently, 36 dentists have been recognized as EnviroStars. In addition, Dr. Rubin has received a 

Washington State Governor's Award, the first dentist to ever do so. 

costs 

Complaints about cost of proper disposal are fiequent since incorrect disposal of waste to the 

sewer may have no initial direct cost to the discharger. Proper disposal may cost more up front, 

but reduces liability and, as we all become more aware of total cost accounting, we realize the 

future costs of today's behavior. 

Pollution prevention is based on a hierarchy of eliminating, reducing, reusing or recycling wastes. 

Preventing pollution is very cost effective. The next step is source control. Once a pollutant has 

been generated, controlling it as close to its source as possible is generally the most effective and 

cost effective way of managing it. Once we accept that proper waste management and disposal 

are necessary, the task is to make it as convenient and cost effective as possible. Our program has 

taken a multi level approach to help dentists control costs. We valuated existing amalgam 

separation technology, developed inexpensive, effective technology, encourage the development 

of more technological options, stimulate the vendors to provide convenient waste management 

services at a realistic cost, provide information and free onsite consultations, modify regulations 
to provide more flexibility, and provide incentives - vouchers up 50% or $500 for services or 

equipment, to reduce hazardous waste. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 1. 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Technolow 

To evaluate methods of separating amalgam particulate from liquid wastewater, King County 

tested the mercury removal capacity of two commercially available separator units and one easily 

fabricated settling unit. The tests were performed in dental offices. Manufacturers’ claims of 99 + 

percent removal during standard testing were compared to results obtained in operating dental 

offices under local conditions. Testing was conducted for filtration, settling, filtration and 

settling, and centrifugation amalgam wastewater treatment equipment. The goal of testing the 

amalgam wastewater treatment units was to find out if treated amalgam wastewater met King 

County’s local sewer discharge limit of 0.2 milligrams per liter total mercury. All operatories in 

this study used vacuum-suction only rather than cuspidor systems, reflecting the practice of the 

majority of dental offices in this region. 

Results from the three amalgam wastewater treatment units are shown in Figure 2. The four 

points on the right side of the graph represent treated wastewater and show remarkable removal 

rates. All values are expressed in mercury loading (milligrams mercury per day). The loading 

figures show the weight of mercury discharged per day, independent of water dilution, 

disinfectants or any other materials. 

The three tested units are shown on the graph as follows: mechanical centrifuge (centrif 1 and 

centrif 2), settling/filtration unit (sethilt) and a simple, fabricated gravity-settling unit (simple) 

designed by a King County chemist and a process engineer - see Appendix 6). The graph shows 

one to four orders of magnitude reduction in mercury after treatment of amalgam wastewater. 

Significant reductions of mercury in the sewer discharged waste stream of dentists are achievable. 

The commercial equipment reduced mercury by 99.9%. Even very basic treatment, such as that 

provided by the “homemade” King County model (less than $100 per unit), removed at least 95 

percent of the mercury from rinse waters. While high levels of reduction are feasible with 

treatment, it was not demonstrated that 0.2 ppm mercury could be consistently achieved with the 

equipment tested. Chemical treatment in addition to physical amalgam removal did produce 

wastewater with a mercury concentration of less than 0.2 ppm. (Tomchick, 1998). 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Demonstration Testing for Vendors of Amalgam Wastewater Treatment Units 

Dentists requested some sort of treatment equipment “approval” by King County to assist them in 

assessing amalgam wastewater treatment units. While King County does not recommend specific 

equipment, a testing protocol was developed in 1995 to demonstrate whether a system 

consistently removes at least 90 percent of mercury under typical conditions that include, but 

were not limited to the standard practice use of in-line amalgam screens and traps. 

Demonstrations included installing the unit in representative dental offices. Requirements for the 

sampling’report also included the vacuum drop associated with the amalgam wastewater 

treatment unit - stated both objectively (inches of Hg via gauge) and subjectively by dental office 

personnel. In addition, the reclamation or disposal of collected sludge and the method of infection 

control had to be explained. Finally, a description of the attention required by the vendor or 

dentist for proper operation and maintenance of the unit had to be provided [see appendices 3 and 

4.1 

Service 

A major gap in the amalgam management issue was the question of reclamation. In 1990, the 

county had only one hazardous waste drop-off option that was available once a month for a fee of 

about $30 per gallon. It requires self-transportation, and has only one location. The material was 

handled as hazardous waste, and not reclaimed. Reclamation of amalgam slq required more 

preparation than solid amalgam particles. Shipping to distant reclaimers had limitations as well. 

Also dentists really wanted a pick-up service, preferably of all wastes -- hazardous and biomedical. Currently there are more services available, several mail-in services for solid amalgam 

exist, one pick-up service, and amalgam separator companies usually provide reclamation service 

as well. In a further effort to stimulate the local market and initiate new waste management habits 

of dental clinics, King County and the local dental society are sponsoring a dental waste pickup 

project which must include amalgam waste. Vendors are encouraged to provide pick-up for 

multiple waste streams and dentists are encouraged to use these services regularly. The county 

pays for the first pick-up. Three vendors have expressed interest, and the dental society will do 

the promotion and register dentists. King County will collect follow up information about the 

effectiveness of the project. 

What Makes A Good System? 

Let’s look at this diagram again [Figure 11. It looks like it ought to be fairly simple to trap this 

stuff- Well, it is and it isn’t. You can’t just stuff some kind of filter in the line somewhere and 

have it work successfully. I’d like to point out some of the difficulties. Although there’s not a 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

lot of volume of water flowing through, it is flowing at a high rate of speed and force, mixed with 

large quantities of air. The speed and force are such that a simple filter is not likely to capture 

very much. Or, if the filter were dense enough to trap the sludge material, it would reduce the 

suction power so much at the chairside that it would be unacceptable. Besides the technical 

difficulties in designing an effective system, there are also behavioral factors. Since dentists are 

not yet very sold on this problem or highly motivated to make changes, anything that interferes 

with their routine or diminishes the effective use of their existing equipment will meet strong 

resistance. Most designs now incorporate some means of slowing down the flow to a trickle that 

can be effectively filtered, without diminishing the suction power. This is usually accomplished 

with some type of aidwater separator tank. The vacuum pump is allowed to pull at the same 

force. The liquid portion of the evacuant drops into a holding tank or container where it can then 

drain or settle through a filter. The air whooshing through the line is vented to the outside of the 

building. This is required by code in any newer offices. It should be pointed out that this air 

contains a significant amount of mercury vapor, as demonstrated in a paper published a couple of 

years ago (Rubin, 1996, see appendix 2). That’s a whole other issue, and we’re not addressing 

that in today’s presentation. At this point, most designs incorporate a filtration or settling 

process, or a combination. A couple of companies have tried using a centrifuge design to 

separate the heavier metals from the liquid. Here is an example of one system that uses aidwater 

separation and a filtration system. Theie are a lot of companies who have put a lot of effort into 

designing systems that will do the trick. Having seen most of them, tested several of them in my 

own office, and worked with these systems for the last eight or nine years, I have learned a lot 

about what works, what doesn’t and why. I’d like to list for you what I feel are essential elements 

of an ideal mercury capturing system for a dental office or clinic. 

1. The system should be effective. That’s the whole point of this. It should be able to prove 

that it can remove 90-99% of all the mercury, regardless of particle sizes in the amalgam 

sludge. At least two municipalities, King County in Washington State, and Minneapolis have 

tested several companies who have been willing to put their products through some testing 

protocols. It does matter how the testing is done. These two municipalities have done a great 

job, and I think their results should be looked at more cIosely than what the manufacturers’ 

claim. 

2. There should be no compromise in suction power. If you just cram some kind of dense filter 

inline with the vacuum pump, the effectiveness of the vacuum at chairside is going to drop, as 

I have mentioned. Again, this would be an unacceptable compromise. 

3. “Hands-Off” feature. If this material is toxic and nasty (which it is), it’s not a good idea to 

have a system where the dentist or staff has to frequently empty containers, decant off liquids, 

or handle or change filters. Ideally a system just sits there and does its job without much hss 

or handling by the staff. Again, if it’s difficult, the staff eventually won’t do it, unless they are 
highly motivated. Then there will be a system supposedly in place that’s really not functioning 

at all. 

4. Recycling. It’s not enough to capture this stuff - it needs to be recycled in order to get it out 

of the loop and keep it out of the environment. The handling of the recycling is not simple, 

but it’s not quite as impossible as it was a couple of years ago. The dentist needs to know 

how to prepare, package and send the collected material to a certified recycler and refiner of 

mercury. Who will take this stuff! How can it be shipped? Who is liable for it once it leaves 

the office? Can liability fall back on the dentist if there’s a problem of improper handling 

somewhere down the road? Past case history indicates that’s possible. It’s difficult, but not 

impossible, for the dentist to find a way to handle this. It’s much easier if the company that 

sold the unit also handles the recycling end of it. Some of the companies offer this service, 

and I’d recommend sticking with a company or dealer that does include doing this for you, 

with all the proper regulations and paper trail of liability adhered to. If a company just wants 

to sell you a system and leave you on your own to figure out recycling, I don’t think that’s a 

very good service. How often the collecting and recycling is done will depend on the design 

of the system. 

5. Simplicity of design is a plus. The fewer moving parts and bells and whistles, the fewer things 

that can go wrong. Easy installation and easy maintenance means fewer problems and lower 

costs. 

6. Quiet operation is a nice feature, though these units are usually installed far away from where 

staff or patients are. 

7, There should be a “Fail-safe” mechanism. What would happen if something clogged the line, 

or the filter got full too soon, or something like that. Are you going to have a toxic spill on’ 

your hands? Could it end up shutting down your vacuum pump? Some effective type of 

bypass design should be able to automatically handle these eventualities. These units are 

usually installed in an out of the way location, not often checked or seen by the office staff. 

8. The unit should install centrally. Looking back at the office diagram,[Figure 1 .] if there are 

filters set at chairside in each treatment room, they can capture all the new amalgam sludge. 

But all these connecting lines, all the way to the vacuum pump, are caked with years of 

buildup of amalgam sludge, prophy paste, saliva and crud, like arteries clogged with 

arteriosclerosis. Clean water passing through these lines is going to continue to pick up 

mercury and pass it along into the waste stream. This has already been demonstrated (Rubin, 

1996). If you install a unit centrally, at the site of the vacuum pump, it will effectively clean 

the whole wastestream before dumping into the sewer system. 

9. Reasonable cost is always important. Realize that you’ll be paying for a system as well as for 

some means of periodic recycling. It’s a good idea to compare companies on the total cost of 

having a system over a five or ten-year period, in order to really see how much it will cost. 

i 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

We have prepared handouts that outline these features (appendix l), as well as a list of some 

known manufacturers who have demonstrated a passable level of effectiveness with testing 

protocols through King County Industrial Waste Division (appendix 5). 

Summary 

Acknowledging that mercury discharge from dental offices is significant is an important first step 

to properly managing dental waste. Technological, logistical, financial and emotional concerns 

have been, and continue to be addressed by both the county and dentists. We have developed 

some solutions and BMP's cooperatively, and continue to get information to those who need it. 

The government may be able to provide information and education, possibly incentives and 

recognition. But it is you, the dentist, who can make the real difference. We.encourage dentists, 

and any dental societies or organizations, to take the opportunity to act proactively on this matter, 

helping to protect the environment and gaining some good community relations at the same time. 

One professional organization, the International Academy of Oral Medicine and Toxicology (also 

called IAOMT) has taken as stand. Through its Standards of Care committee, it has 

recommended that all its members who are practicing dentists install proper mercury recapturing 

systems now. This is an excellent opportunity for individual dentists, and for dental organizations 

to lead the way to a cleaner, healthier environment. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

References and Bibliography: 

Berglund, P. “Quantification of Mercury Discharges to the Wastewater Treatment Plant”. WEF 

MonoIogue: Controlling Dental Facility Discharges in Wastewater. In pre-publication, 1998. 

Dickey, P. 

1) Database of safer substitutes for household hazardous products : phase one report / by Philip 

Dickey. Seattle, WA. : Municipality of Metropolitan Seattle, 1990. 

2) Database of safer substitutes for household hazardous products : phase two report / by Philip 

Dickey. Seattle, WA. : Municipality of Metropolitan Seattle, 199 1 

Galvin, D.V. Why Household Hazardous Waste Management Is Needed. p. 5 1-58 

from the Proceedings of the Sixth National US EPA conference on household hazardous waste 

management (December 3-7, 1991). Publisher info: Andover, MA. : Dana Duxbury & Assoc. 

Gurbam, F.C. et a1 1979. Control Of Heavy Metal Content Of Municipal Wastewater Sludges. 

Washington, DC : National Science Foundation. 

Jenkins, D. “The Contribution Of Heavy Metals To Wastewaters From Household Cleaning 

Products“ Report by Reed Corporation for the Soap and Detergents Association, July 1990. 

Local Hazardous Waste Management Program (1993) Waste Management Guidelines for King 

County Dental Offices. Municipality of Metropolitan Seattle, Seattle, WA. 

Daniel P. Rourke. City And County Of San Francisco Consumer Products Heavy Metals 

Inventory. p. 301-305 from the Proceedings of the Sixth National US EPA conference on 

household hazardous waste management (December 3-7, 1991). Publisher info: Andover, MA. : 

Dana Duxbury & Associates. 

Rubin, P. and Ming-Ho, Y. “Mercu y Vapor in Amalgam Waste Dischargedfrom Dental OfJice 

Vacuum Units ” Archives of Environmental Health, vol. 5 1 No. 4, July/August 1996. 

I 

Savina, G. (1 995) Dental Waste Education and Outreach, Project Work Plan. Hazardous Waste 

Management Program, Municipality of Metropolitan Seattle, Seattle, WA. 

The Merck Index. (1 989). 1 1 th Ed., Merck & Co., Inc., Rahway, NJ. 

Tomchick, L., C. Balogh and G. Savina. “Planning and Implementing a Source Control 

Program. ” WEF Monologue: Controlling Dental Facility Discharges in Wastewater. In prepublication, 1998. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Water Pollution Control Department (1995) Demonstration Testing of Amalgam Wastewater 

Treatment Units. Municipality of Metropolitan Seattle, Seattle, WA. 

Water Pollution Control Department (1994), Dental Office Project: Testing Treatment 

Technologies for Amalgam Rinsewaters. Metro Hazardous Waste Management Section, 

Municipality of Metropolitan Seattle, Seattle, WA. 

Welland, C. (1991). Dental Office Waste Stream Characterization Study. Municipality of 

Metropolitan Seattle, Seattle, WA. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Appendices: 

Appendix 1. Elements Of An Ideal Mercury Recovery System 

I ~ Effective - 90-99% 

2. No compromise in suction power 

3 ~ “Hands-Off” operation 

4. Recycling provided by vendor as part of service 

5. Simplicity of design - easy installation and maintenance 

6. Quiet operation 

7. “Fail-safe” mechanism to prevent blockage, leakage, etc. 

8. Central installation rather than at chairside 

9. Reasonable cost - look at total cost, including periodic recycling cost 

We recommend that you ask questions ofprospective vendors until you are satisjed. qpossible, 

tv to talk with some existing customers as references. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Appendix 2. 

Mercury Vapor in Amalgam Waste Discharged from Dental Office Vacuum Units 

Reprinted from Archives of Environmental Health, 

Published by HELDREF PUBLICATIONS, 13 19 Eighteenth Street, NW, 

Washington, DC 20036-1802. 

(202) 296-6267 * Fax (202) 296-5 149 

Reprinted with Permission 

Abstract. Clinical procedures in dental offices generate quantities of waste slurry or fine 

particulate matter, much of which is derived from dental amalgam filling material. This 

mercury-containing material is discharged into waste streams via the dental office vacuum pump 

system. This system also discharges large quantities of air, either into the atmosphere exterior to 

the office building or into the sewer system, depending on the type of equipment used. The 

purpose of this study was to investigate whether the discharged air contained mercury vapor. 

Paul G. Rubin Ming-Ho YU 

Broadway Dental Center 

Seattle, Washington 

Center for Environmental Sciences 

Huxley College of Environmental Studies 

Western Washington University 

Bellingham, Washington 

DENTAL AMALGAM RESTORATIONS 

("silver fillings") have been the most widely 

used fillings for more than 160 y. These 

fillings contain approximately 50% mercury 

(Hg). Elemental Hg vapor has been shown to 

escape from these fillings in the mouth. 1-9 

Skare and Engqvist 10 reported recently that 

the number of afnalgam surfaces was related 

to the emission rate of Hg into the oral 

cavity and to the excretion rate of Hg in 

urine. 

Some amalgam "scrap" is generated in dental 

offices when amalgam fillings are placed or 

removed. The scrap is typically composed of 

small chunks of amalgam material, a slurry of 

grindings of extremely small particles, water, 

and saliva. The scrap is removed from the 

patient's mouth with a chairside suction or 

vacuum device that is powered by a vacuum 

pump located in a more remote part of the 

office or building. A mixture of the amalgam 

waste, containing Hg, water, saliva, and 

other debris, travels through pipes and tubing 

to the vacuum pump, where it is eventually 

discharged into the waste-water line that 

leads to the municipal sewage system. In 

some offices, the air and liquid portions of 

the evacuant are separated in an aidwater 

separator tank. The liquid and solid materials 

are drained into the wastewater while the air 

is vented elsewhere, usually to the outside of 

the building. Questions have been raised 

about the ultimate fate of this amalgam slurry 

and the possible environmental impact of its 

contents, particularly Hg. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

If Hg vapor can be released from the 

amalgam in the human mouth, it is also 

possible that the vapor could be released 

from the amalgam scrap. Little information is 

available about such a possibility. We, 

therefore, studied air samples collected fi-om 

eight sites at which air is discharged 

externally fi-om the dental office vacuum 

systems. 

Material and Method 

A total of eight sites were selected within 

and around the city of Seattle, Washington, 

for this study. The sites were numbered 

randomly from one to eight. A single dentist 

occupied some of the dental offices, whereas 

others were located in buildings in which a 

central vacuum pump served several dentists' 

offices. Some vents were located on the tops 

of buildings, and others were housed a few 

feet above ground level. Site five had a vent 

located approximately 1.5 m fi-om the 

ground in an alley, and it was proximal to car 

and foot traffic. 

A one-time "spot" air sample was taken at 

each of the discharge vents, and the 

concentration of Hg was determined three 

times during a 1 - to 2-mk period. in 

addition, Hg release during an entire day was 

studied at site one; air samples were taken 

periodically at 30-min intervals from 7 A..M. 

to 5 P. M. 

Concentrations of Hg were determined with 

a Jerome 43 1 -X mercury vapor analyzer 

(Arizona Instrument Company [Phoenix, 

Arizona]). This instrument was designed for 

the accurate analysis of Hg vapor in the 

workplace environment, for locating Hg 

spills, and for studies of intra-oral Hg vapor 

levels. In the presence of Hg vapor, a thin 

gold film undergoes an increase in electrical 

resistance proportional to the mass of Hg in 

the sample. Sample air is filtered to remove 

any acidic gases that might interfere with the 

sensor's response to Hg. The features of the 

analyzer are the following: range = 0-0.999 

mg Hg/ml, resolution = 0.001 mg/m3, and 

accuracy = f 5%. Air is drawn into the 

analyzer for 12 s at a flow rate of 750 

cc/min. The manufacturer calibrated the 

instrument for us, and it was sent directly to 

us immediately prior to this study. 

We did not conduct any direct measurements 

of air volume discharged at these sample 

sites, but we obtained the manufacturer's 

specifications regarding volume flow for the 

different types of vacuum units. This 

information was used to estimate the total 

daily discharge of Hg, based on the 

determinations of the Hg vapor 

concentrations. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Discussion 

Spot-sample determinations and results of 

the 17 samples collected during an entire day 

at site one were similar (i.e., 0.103 versus 

average of 0.094 mg/m3, respectively [Table 

1, Fig. 11). The "spot" sample appeared to 

be a valuable indicator of an individual 

office's Hg discharge level. 

The levels of Hg vapor were higher in older 

dental offices, compared with newer 

facilities. Relatively high levels of Hg were 

detected at older office sites, even when no 

patient was being treated at the time of 

measurement. This suggested that Hg vapor 

was being released from amalgam residues 

that existed somewhere in the office 

plumbing. In one office, a piece of plumbing 

no longer in use (i.e., an old separating tank) 

released 0.332 mg/ml Hg vapor, thus 

implying that Hg vapor could be released 

from the static residue of amalgam sludge. A 

simple turbulence of air and water over 

existing amalgam slurry also seemed 

sufficient to cause release of Hg vapor. The 

environmental or health risks of this level of 

emission is not known. For purposes of 

comparison, the Occupational Safety and 

Health Administration (OSHA) cites an 8-h 

time-weighted average (TWA) Hg exposure 

limit for humans in the workplace at 0.050 

mg/m3, The OSHA also has an ,acceptable 

source impact level" of 0.2 pg./ml for 

nonalkyl Hg vapor. 

Perhaps the total quantity of Hg released in a 

given period of time is relevant. We could 

not measure outflow volume of air directly at 

the test sites. A rough estimate could be 

made, based on manufacturer's 

specifications. For the types and brands of 

vacuum pumps seen in this study, we 

estimated a flow rate of 0.5 to more than 5.0 

ml/min. An attempt was made to correlate 

this information with the test data, making 

some assumptions on the running time of the 

pumps per day (they typically run 

continuously all day), per year, per dentist, 

etc. The total quantity of Hg released per 

day per dentist in these test offices was 

estimated to be 60 mg. Extrapolation of that 

result to 112 000 U.S. dentists," who work 

at least 200 d each year, led us to conclude 

that the total quantity of Hg released 

nationwide each year may exceed more than 

a ton. A more widespread study and careful 

volumetric analysis are needed to obtain a 

more accurate picture. 

Whether Hg vapor levels exist-and to what 

degree -in sewage systems that receive 

discharge air directly still remains uncertain. 

We would expect the discharge amounts to 

be similar to the levels reported in this study, 

but the significance of occupational exposure 

to workers in that environment is a question 

for further study. Table 1, Fig 1. 

Before this study, no data had been 

published about escape of Hg from dental 

waste material, under naturally occurring 

conditions. Release of Hg in our study 

occurred, absent any extremes of forces or 

temperatures; therefore, such a result 

appears to be cause for some environmental 

concern. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Table 1 .-Concentration of Mercury (Hg) Vapors in Air 

Samples Collected at Test Sites 

No. dentists Concentration 

Site no. at office site {mg H@m9 

1 2 0.103 f 0.011' 

2 1 0.013 f 0.001 

3 5 0.237 -f 0.020 

4 2 0.010 f 0.001 

5 10 0.1 68 rt 0.023 

6 2 0.060 -f 0.01 1 

7 2 0.023 f 0.003 

8 4 0.126 f 0.001 

Average concentration 0.092 f 0.008 

*Concentration values presented as means 

tions. 

standard devia0.3 

0.25 

0.2 

r" 

c) E 0.15 

P 

0.1 

0.05 

D 

D 

8 

8 

8 

I 

I I t , I I I I I i I 

6 7 8 9 10 11 12 13 14 15 18 17 

Tlnw ot dty, Hr 

Fig. 1. Results of Hg analysis for air samples coflected at site one during a day, from 200 A.M. to 5:OO P.M. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Results 

All the air samples collected for analysis contained, on average, 0.092 mg Hg/m3. The level of 

Hg, however, varied markedly with sampling site and ranged fi-om 0.0 10 mglml to 0.237 mg/m3 

(Table 1). Mercury levels were higher in samples collected at sites of older dental offices than in 

samples obtained at newer offices. The two sites at which the lowest concentrations were found 

(sites two and four) were at newer offices that contained newer plumbing systems. No attempt 

was made to record the type of dental procedures that were performed on patients at the time the 

samples were taken. Some .samples were obtained at times during which there was no 

active-dental treatment being performed by dentists. 

The results of Hg analysis for air samples collected from 7:OO A.M. to 5:OO P.m. at site one are 

shown in Figure 1. During the day, a continuous output of Hg fi-om this particular site was 

observed. Mercury levels ranged from 0.048 to 0. 160 mg/m3 (average = 0.094 m m3). 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

References 

I . Craig RG (Ed). Restorative Dental Materials. St. Louis, MO: Mosby, 1980; pp 8-1 1, 163. 

2. Vimy MJ, Lorscheider FL. Intra-oral air mercury released from dental amalgams. I Dent Res 

3. Vimy Mj, Lorscheider FL. Serial measurements of intra-oral air mercury: estimation of daily 

dose from dental amalgam. I Dent Res 1985; 64:1072-75. 

4. Patterson JE, Weissberg BG, Dennison Pj. Mercury in human breath from dental amalgams. 

Bull Environ Contamin Toxicol 1985; 34:459-68. 

5. Vimy Mj, Lorscheider FL. Dental amalgam mercury daily dose estimated from intra-oral vapor 

measurements: a predictor of mercury accumulation in human tissues. J Trace Elem Exp Med 

6. Berglund A. Estimation by a 24-hour study of the daily dose of intra-oral mercury vapor 

inhaled after release from dental amalgam. J Dent Res 1990; 69: 1646-5 1. 

7. Reinhardt JW. Side effects: mercury contribution to body burden from dental amalgam. Adv 

Dent Res 1992; 6:llO-13. 

8. Engle JH, Ferracane JL, Wichmann J, Okabe T. Quantitation of total mercury vapor released 

during dental procedures. Dent Mat 1992; 8(3): 176-80. 

9. Visser H, Pieper K, Isemann M, Stalder K. A prospective study on the incidence of mercury 

levels in dental students. 11. Correlation analysis. Dutsch Zahnarztl Z 1991; 46(8):555-57. 

10. Skare 1 , Engqvist A. Human exposure to mercury and silver released from dental amalgam 

restorations. Arch Environ Health 1994; 49:384-94. 

1 1. Welland C. Dental Office Waste Stream Characterization Study. Municipality of Metropolitan 

Seattle (METRO). Seattle, WA: Industrial Waste, MS Lab; 1991. 

12. Occupational Safety and Health Administration. Safety factors. Fed Reg 1992; 57:26048. 

13. American Dental Association. Chicago, IL: Department of Surveys, 199 1. 

1985; 64: 1069-71. 

1990; 3:lll-23. 

The authors thank the Arizona Instrument Company for assistance with the mercury- vapor 

analyzer used in this study. 

Submitted for publication May 25, 1995; revised; accepted for publication December 7, 1995. 

Requests for reprints should be sent to Paul G. Rubin, D.D.S., F.I.A.O.M.T., Broadway Dental 

Center, 3 10 Harvard Avenue East, Seattle, WA 981 02. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Appendix 3. Testing Protocol for Amalgam Separation Equipment 

Demonstration Testing of Amalgam Wastewater Treatment Units 

Goal: To consistently demonstrate a minimum of 90 percent removal of MERCURY from 

amalgam wastewater under representative conditions. 

Each vendor interested in installing amalgam wastewater treatment units within Metro's service 

area must demonstrate to Metro that the system will consistently remove at least 90 percent of 

mercury under typical conditions*. This demonstration must include installing the unit in 

representative dental offices. (For the period July 1, 1994 to May 1, 1995 'representative dental 

offices' must include a minimum of three King County dental offices). Vendors must provide 

Metro with both a description of the specific testing conditions associated with each 

demonstration dental office and the Monitoring Plan for the demonstration period. The 

Monitoring Plan should include: (a) a diagram and photo showing sampling location and 

treatment unit placement in relation to chairs and vacuum pump; (b) composite sampling 

procedure; (c) sample splitting procedure; (d) sampling handling procedures; and (e) number of 

samples. 

Based on Metro's experience in characterizing wastewater from dental offices and the 

performance of pretreatment systems in other settings, the following are minimum demonstration 

requirements: 

1. 

2. 

ESTABLISH SAMPLING POINT. In most cases the sampling point will remain constant 

throughout the test period, therefore advance consideration for the location of the sample 

point in relation to the installed unit must be considered. The point of sampling will usually be 

located between the operatory chair and the vacuum pump, but in all cases sampling must 

occur before amalgam wastewater mixes with water that will not be treated by the amalgam 

wastewater treatment unit. 

SAMPLE TO ESTABLISH MERCURY CONCENTRATION IN UNTREATED 

WASTEWATER. Prior to the actual installation of the amalgam wastewater treatment unit, 

sampling must consist of a minimum of five continuous weeks of operation to establish a mean 

weight of discharged mercury (in grams) based on weekly mercury concentrations and 

wastewater volumes. For each amalgam removal unit, a minimum of one composite sample 

per week must be collected totaling a minimum of 5 composite samples prior to installation. 

Each weekly analysis must consist of all the representative composite samples (one or more) 

taken that week. For each sample, the total volume of wastewater and the volume of the . 

sample must be reported. Total weight of mercury can then be calculated. Each sample must 

be analyzed by an EPA or WDOE certified laboratory for total mercury using EPA Method 

7470 (or equivalent, e.g. Method 245. 1). Please refer to "Recommended Sampling Protocol 

for Dental Amalgam Wastewater". 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

PauI G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

3. 

4. 

5. 

6. 

INSTALL THE TREATMENT UNIT. The treatment system must be installed in a minimum 

of three dental offices for each type of vacuum system (wet vs. dry) for which certification is 

sought. The offices should be those which routinely work on several amalgam placements or 

removals per day. 

SAMPLE TO ESTABLISH MERCURY CONCENTRATION IN COLLECTED SLUDGE 

AND TREATED WASTEWATER. Following installation of the treatment unit, the total 

grams of mercury collected over the five week post-installation test period must be reported 

based on the total weight of the collected solids and its mercury concentration. 

In addition, for those treatment units installed upstream of the vacuum pump, treated 

wastewater must be collected. Sampling shall consist of a &mum of five continuous weeks 

following installation totaling a minimum of 5 weekly composite samples. Each weekly 

analysis must consist of the entire representative composite samples (one or more) taken that 

week. SampIes should be taken downstream of the installed unit and should not be taken until 

the unit has reached a “steady state”. As in #2 above, these samples will establish a mean 

weight of discharged mercury (in grams) based on weekly mercury concentrations and 

discharged water volumes. 

REPORT TO METRO. Along with the sampling results obtained for each installation, the 

vacuum drop associated with the amalgam wastewater treatment unit - both objectively 

(inches of Hg via gauge) and subjectively - must be reported. Further, the transferability of 

collected sludge and the method of infection control must be explained. Finally, a description 

of the attention required by the vendor or dentist for proper operatiodmaintenance must be 

provided. 

Questions regarding these requirements should be directed to Rick Renaud, King County 

Industrial Waste Investigator, at (206) 689-3007. 

* ‘Typical conditions” include, but are not limited to, the standard practice use of in-line 

amalgam screens and traps. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Appendix 4. Recommended Sampling Protocol for 

Dental Amalgam Wastewater (10/24/94)* 

These recommendations are to be used in conjunction with King County’s “Demonstration 

Testing of Amalgam Wastewater Treatment Units”. They apply to the sampling of treated 

and/or untreated dental amalgam wastewater collected after the operatory and before the 

vacuum pump. The sampling “collector” accumulates all operatory wastewater produced 

during the week (sample). The total volume is then measured and a representative portion 

taken for laboratory analysis (subsample). 

1. Sampling set-up 

0 Fittings, tubing and sampler should be installed to avoid rough or low spots where particulate 

may collect and thus not reach the sampling collector. 

2. Sample collection 

To obtain representative samples it is important that there are no major deviations fi-om the 

typical operatory routine. Do not flush the lines with excess water before or during sampling. 

Most of the metals will be in the particulate matter. Care must always be taken in the 

collection, splitting and subsampling of samples with particulate to assure that the particulate 

is evenly distributed so that the sample is truly representative of the wastestream. 

Mix sample within the collector well before subsampling. Cap and invert the collector 8 - 10 

times and then swirl while pouring sampIe(s) to keep the particulate well distributed. 

Pour at least one duplicate sample (for analysis) of untreated wastewater during the first 5- 

week test period and one duplicate of treated wastewater during the second five-week test 

period to demonstrate representative splitting technique. 

Measure subsample volume and total sample volume such that sample integrity is maintained. 

0 Pour all samples, including duplicate(s) into measured sample bottles (approx. 500 rnL,). 

Pour remaining collected sample in a graduated cylinder (approx. 1 - 5 L). Some residue 

may remain, especially in untreated samples. 

Rinse particulate residue from the sample collector 2-3 times with a little of the 

supernatant from the top of the graduated cylinder. Assure that whatever residue film 

remains is insignificant for volume measurements. 

Total the volumes: sum the volumes of those samples poured into the sample bottles and 

the remaining volume poured from the collector into the graduated cylinder. Record total 

volume. 

0 

0 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

0 Preserve sample(s) with nitric acid to pH<2. Your laboratory may be able to provide this 

service if samplefs) can be delivered to them immediately. 

Follow the analytical laboratory sample handling procedure. 

0 Record type and volume of disinfectant used in the dental office. 

* This protocol was developed to assure sample integrity and interpretable data and is based upon 

the I992/93 Dental Amalgam Separation Study conducted by the Local Hazardous Waste 

Management Program in King County 

a. 

e 

0 

4. 

0 

0 

6 

8 

Analysis 

Notify the laboratory of the type of sample and the anticipated high levels of metals in the 

untreated wastewater samples (e.g. up to 2000 ppm mercury). High concentration of metals 

can cause instrumentation contamination and carryover. The laboratory instrument used for 

mercury analysis has a narrow and very low linear range which likely will require sample 

dilution at and by the laboratory before analysis. 

The lab should use care in subsampling and dilutions. Dilutions of 1/10,000 or more may be 

necessary for untreated samples. Digesting the entire submitted sample and then making serial 

dilutions using digestion acids may be the best approach. The lab’s QNQC data should verify 

this. 

Quality Assurance/Quality Control 

Use clean sample bottles of a known volume. Test for contamination. Soak in nitric acid 

solution, if necessary. Your laboratory may provide appropriate bottles or help in bottle 

selection. 

CIean the sample collector bottle: 

0 

Rinse and wash a 4 Liter or larger sample collection bottle. 

Soak sample collection bottle and lid in disinfectant (Collect a sampIer blank to check for 

possible contamination from the disinfectant; if detected the disinfectant should be 

changed before sampling begins. Wescodyne seems to work well.) 

Rinse thoroughly (8x) with warm or hot tap water 

Rinse 3x with deionized water 

Shake out and cap bottles 

0 

6 

0 

Use a “new” sample collector after instalhg the amalgam removal unit. The expected high 

levels of metals in untreated wastewater will likeIy contaminate the sample collector used in 

the first five-week phase of the testing protocol. 

The lab should provide QNQC information for blanks, standardization, standard reference 

materials, dilution factors, seriaI dilution analysis, sample replicates and spikes for every 

analytical batch (and every ten samples if a batch exceeds ten samples). 

2.4 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

5. Safety 

0 Untreated dental wastewater must be handled with caution due to its potentially infectious and 

hazardous characteristics. It is probably prudent to handle according to bloodborne pathogen 

procedures. 

Appendix 5. Tested Amalgam Separators 

The Industrial Waste section of King County has received data from the following vendors as 

evidence that their specified unit is at least 90% effective in removing amalgam from dental 

wastewater in the Seattle area. 

DRNA (tel. 800-360-1001) 

Metasys (tel. 905-528-0078) 

R&D Services (tel. 206-525-4994) 

Rebec (tel. 800-569-1088) 

Safety-Kleen (tel. 800-669-5984) approval status unknown at this time. 

Note: King County acknowledges that there may likely be several other market-available 

amalgam separation units or technologies which can meet the minimum 90% removal criteria, but 

data for these units have not been submitted for our analysis. For example, there were a number 

of other vendors who began demonstration testing in Seattle but withdrew from the process in 

response to the county's decision to postpone the dental waste rule promulgation. Contact Rick 

Renaud (206-689-3007) for more information. 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Appendix 6. Dual Chamber Amalgam Waste Separator 

Materials: 

4” schedule 40 PVC pipe - 2@ 12 inches 

4” PVC plug - 2 each 

4” PVC coupling - 2 each 

4” PVC threaded cap - 2 each 

4” PVC male adapter - 2 each 

clear silicon caulk - 1 each 

Fig. 

baffle: plastic panel (cut from waste basket) 

PVC glue - 1 each 

Nalgene barbed bulkhead fittings (size to fit 

vacuum hose) - 2 each 

vacuum tubing - size to fit operatory, several 

feet 

- 2 4+~7 x 1277 

Cost of Materials: Approximately $60. 

Tools: 

Electric drill drill bits: MY, 518” paddle, 1 118” paddle 

Screwdriver pliers hand saw Keyhole saw or similar tool 

Utility knife straight edge bar clamp 

Assembly (make two): 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

Mo&t barbed fitting in cap according to instructions. Depending on cap thickness, you may 

need to recess holes.* 

Make two shallow cuts at opposing angels along inside length of pipe for baffle. Use jig for 

straight cut. 

Cut plastic baffle and pressure fit into slots. Mark location of baffle on outside of pipe. 

Assemble and glue together PVC parts (except threaded cap.) When assembled, baffle will be 

several inches above bottom of chamber to allow for sludge accumulation and several inches 

of headspace at the top of the chamber. 

Push short piece of hose or other tubing over inside of barbed fittings. The one on the inlet 

side is to guide wastewater into one of the chambers. A longer one on the outlet side is to 

extract treated effluent. Hoses must not extend beyond top of baffle.” 

Screw cap on, noting position of inlet and outlet relative to baffle. 

Test and seal with silicon caulk as necessary. 

Insert both units in series in vacuum line bew’een operatory and pump using vacuum hose as 

needed. 
* 

top of pipe for outlet. Special gaskets or shims may be required to fit curved surfaces. 

Alternately, mount one barbed fitting off center in cap for inlet and other barbed fitting near 
Cynthia Welland Balogh 

King County 

Local Hazardous Waste Management Program 

Seattle, Washington 

Paul G. Rubin, DDS 

Academy of Oral Medicine and Toxicology 

Seattle, Washington 

Cynthia Welland Balogh works for the Technical Assistance and Pollution Prevention Local 

Hazardous Waste Program for King County in Washington. She has been involved locally and 

nationally in dental amalgam characterization and treatment since 1990. She can be contacted 

at the Technical Assistance and Pollution Prevention Local Hazardous Waste Program, King 

County, 130 Nickerson Street, Suite 100, Seattle, Washington 981 09-1 658. Phone: (206) 689- 

3075. Fax: (206) 689-3070. 

Paul Rubin, DDS, FIAOMT is co-chair of the Environmental Committee of the International 

Academy of Oral Medicine and Toxicology, where he also serves on the Board of Directors. Dr. 

Rubin is in private practice of dentistry in Seattle. He graduated from the University of 

Washington School of Dentistry. He can be contacted at 310 Haward Avenue East, Seattle, 

Washington 981 02. Phone: (206) 324-1 100. Fax: (206) 324-671 I. 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Dental Office Waste Management: 

Safety and Regulatory Compliance Issues. 

* Regulatory Compliance 

Accreditation & Certification Preparation 

Corporate Compliance 

Topics to be covered 

* Waste management safety & liability areas of concern in dentistry 

Specific OSHA issues related to waste management 

How to develop your own compliance program 

WHAT HAPPENS TO YOUR WASTE? 

.by MedSafe's Compliance Department 

A typical response -"Some guy picks it up, and he takes care of it. What they do with it is their 

problem!" Unfortunately, it is your problem and the ultimate disposition of waste is your 

responsibility. The term "Cradle to Grave" is commonly used when discussing regulated waste 

issues. If you generate regulated waste (sharps, fixer solution, others) you are responsible for it 

..forever. It is very important that you check with your waste hauIer for appropriate licensing. If 

your questions are not taken seriously or are responded to in a defensive manner, you might 

consider Iooking elsewhere .. there are many! 

The following guidelines should be helpful in locating an acceptable Treatment Storage and 

Disposal Facility (TSDF): 

Initial screening 

During the initial screening of a TSDF, you should ask for a copy of permits held by the company. 

It is important to see that the waste hauler has a current permit and is licensed to accept and treat 

your particular type of waste. This information should be readily available. 

You should also ask specific questions concerning qualifications and training of their staff 

members. Their employees must be trained in Occupational Safety and Health Administration 

(OSHA), Environmental Protection Administration (EPA), and Department of Transportation 

(DOT) regulations. 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Your interview should also determine the type of treatment that will be rendered for your 

particular types of waste. You need to know if your waste will be incinerated or if it will be 

buried in a landfill--where it can eventually come back to haunt you! 

Take the Tour 

Consider conducting an on-site tour of the waste facility. While in many cases this may not be 

practical, you might ask your professional association to go for you. As unexciting as it sounds, it 

could save you from making a costly mistake. If the waste is not disposed of properly, if it's 

found washed up on a beach somewhere, you, as the generator of that waste, are the one who 

Pays. 

If you visit, you should be interested in seeing the storage and treatment areas of the facility. 

Assess the geographical location of the facility and its potential ramifications. For example, if it is 

located in a neighborhood, next to a playground, or near a stream, it is probably not your best 

choice. It may still be acceptable but there should be an in-depth review of health and safety 

practices, storage containment and transfer stations, security and warning signs, etc. 

Again, appropriate operating permits should be reviewed and copies retained for your files. It is 

important to know that even though that generator possesses a permit, this does not relieve you 

of responsibility for proper disposal of your waste. Permits may be expired or revoked. A call to 

the state licensing authorities is probably well advised. 

Financial Resources 

Examine the financial health of your waste hauling company. Financial resources need to be 

adequate in case the waste facility is closed. If it lacks adequate financial resources, the 

generator--that means you, again--can be tapped for the cost of closure. 

Choosing a TSDF requires more study than merely analyzing the cost and frequency of pick-up of 

your waste. Take a few steps now to minimize your risk. Be wise, be informed, and be 

responsible. 

Waste Management in context ... 

j.. how you deal with waste is part ofyour facility's overall compliance program ... . 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Safety/Risk Management Program Components 

Facility Safety Policy Statement 

Hazard Communication and Exposure Control Program 

Program Overview 

Program Summary 

The Hazard Communication Plan (HCP) 

Hazard Communication Standard 

Hazardous Chemical Inventory Procedure 

Hazardous Chemical Definition 

Material Safety Data Sheet (MSDS) Overview 

Hazardous Chemical Labeling 

Chemical Labeling Guidelines 

MEDSAFEB Hazardous Material Identification Chart 

Exposure Control Plan (ECP) 

Occupational Exposure to Bloodbome Pathogens 

Exposure Determination 

Epidemiology: Diseases and Symptoms 

Universal Precautions 

Clinical Protocols 

Standard Operating Procedures (SOP'S) 

Handwashing 

Glove Protocol 

Treatment Area Maintenance Protocols 

Laboratory Procedure Protocols 

Housekeeping 

Cleaning & Decontamination Protocols 

Protocols for Using Chemical Disinfectants/Sterilants 

Blood Spill Protocols 

Laundry 

Waste Management 

Communication of Hazards 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Hepatitis B Virus (HBV) Vaccination Program 

Post-Exposure Evaluation and Follow-Up 

Training and Communication 

Recordkeeping 

Employee Training Acknowledgment 

Contractor Training Acknowledgment (Optional) 

Fire Extinguisher Location Chart (Optional) 

MSDS Request for New Products 

MSDS Request For In-Stock Products 

Hepatitis B Vaccination Status Form 

Hepatitis B Vaccination Declination Form 

Post-Exposure Evaluation Packet Summary 

Post-Exposure Evaluation Check-Off List 

Source Individual Post-Exposure Notification 

Accident InvestigatiodIncident Report 

Employee Post-Exposure and Follow-Up Examination Status Form 

Healthcare Professional Opinion Form (Exposed Individual) 

Healthcare Professional Opinion Form (Source Individual) 

Cleaning and Decontamination Schedule 

S-pore Testing Log (Optional) 

PPE Monthly Inspection(Optiona1) 

PPE Monthly Inspection Log (Optional) 

TB Section 

Appendix A: Standards 

1. .................................... Hazard Communication Standard (29 CFR 1910.1200) 

2. ............................................ Occupational Exposure to Bloodborne Pathogens 

3. ........... Access to Employee Exposure and Medical Records (29 CFR 1910.20) 

Appendix B: Glossary of Common Terms 

Appendix C: Sample OSHA Forms 

Appendix D: References Not Cited 

MedSafe Order Forms: .............................................................. MedSafe Order Forms 

Appendix E: Resource Guide 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Regulatory and Accreditation Requirements at a glance. .. 

Healthcare Organizations 

# REGULATORY COMPLIANCE* 

D OSHA Compliance 

On-site Audit of Hazards & Documentation 

Review of Exposure Risks 

Written Report of Recommendations 

Hazard Communication 

Bloodbome Pathogens 

TB Prevention 

Ergonomics 

Lifting Safety 

Air Quality 

Violence in the Workplace 

General Safety 

Lock Out /Tag Out 

FireElectrical Safety 

Ladder SafetyFall Protection 

MSDS Management 

Hazardous Product Labeling System 

On-site Audit with Recommendations 

Procedures Manual Development 

QNQC Programs 

Initial Staff Training 

Ongoing Program Maintenance 

Title 111, Facilities Audit 

Written Bamer Removal Plan 

Compliance Documentation 

ADA Sensitivity Training 

On-site Audit with Recommendations 

Compliance Documentation 

Ongoing Program Maintenance 

Information and Reporting System 

a Program Maintenance 

Program Updates 

New Hire Training 

Quality 

CLIA Compliance 

D ADA Compliance 

n Controlled Substance Management 

Initial Staff Training 

Multi-Site Safety Management 

*All programs must be site-specific 

0 CORPORATE COMPLIANCE 

Evaluation 

Documentation 

Training 

Fraud & Abuse 

Stark I/StarkII 

CI ACCREDITATION PREPARATION* 

# Managed Care ComplianceROC 

Survey Preparation (JCAHO, AMA, NCQA, 

AAAHC) 

Utilization Management 

Credentialing 

Preventative Health 

Rights and Responsibilities 

Medical Records 

Quality Improvement 

Practices & Procedures Development 

0 LOSS REDUCTIONDUSK MANAGEME 

0 Employee Policies 

Employee Handbook 

Harassment Training 

Violence in the Workplace 

Purchase/Sale Reporting 

Facility Risk Management 

# Due Diligence 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Compliance and Accreditation requirements for 

Dental and other Healthcare Facilities 

General areas to be addressed by a dental organization include the following: 

A. Safetv and Regulatorv Compliance Requirements 

Primary Components 

1. OSHA Compliance and Hazard Assessment 

A thorough review of your facility’s practices and procedures, work environment exposure 

risks and existing risk managementkafety programs should be conducted, with formal written 

recommendations provided to management, to assist in the development and implementation 

of appropriate corrective actions. 

2. Safety Compliance Manuals and Documentation 

The organization or facility must develop facility specific Compliance Manuals and 

documentation including OSHA’s Hazard Communication, Bloodborne Pathogens and 

General Safety standards individualized to each facility plus abstracts and reference materials 

for relevant regulations. (This could include state mandated X-ray, Chemotherapy, safety 

committee or other written safety plans as specified.) 

3. Material Safety Data Sheet (MSDS) Manuals and Product Labels 

A time-consuming, yet critical component of a facility safety program is the assembly of 

required MSDS Directory and Catalog individualized to your facility, along with labels for all 

hazardous products transferred to secondary containers. 

4, Staff Training 

Complete Staff Training should be provided through on-site trainings at your facility, 

consisting of approximately 3 hours of instruction per session (in satisfaction of OSHA’s 29 

CFR 1910.1200 and 29 CFR 1910.1030). 

5. Ongoing Program Maintenance 

The employer must make an ongoing commitment to program maintenance, through (a) 

continuing documentation updates reflecting new or revised regulations, specific advisories 

and newsletters, (b) ongoing training availability for new hires, and training for all staff as 

regulations change, (c) ongoing MSDb acquisition and documentation update, (d) a program 

of follow-up inspections and site visit reports to management, as well as required annual 

training of staff and, (e) automatic on-site training in the case of a change in a facility’s 

Program Coordinator. 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

B. Accreditation Preparation Requirements 

Primary Requirements 

1. On-Site Survey and Report 

A thorough review of areas important to facility accreditation issues should be conducted, 

including: 

Office environment 

Practices and procedures 

Appointments and scheduling 

Quality Management 

Medical records 

Policy documentation 

0 Informed consent, follow-up 

Medication 

Billing and collections 

0 Safety and infection control 

Contracts 

Termination of care 

0 Other specialty specific protocol 

2. Development of Required Documentation 

For any deficiencies identified, physician organization management must then continue with 

development of required plans and/or practices and procedures (including any plans identified 

under ‘other regulations’, see section C below, if necessary). 

3. Orientation to Accreditation 

Accreditation preparation involves changes in organizational culture and procedure. Facility 

Coordinator(s) should be designated. These individuals will take a substantial part of their 

time training staff, and conducting workshop/conferences with management as to performance 

oriented ongoing responsibilities for accreditation and MCO provider contract maintenance. 

4. Ongoing Services 

Regulations change, thus the facility Program Coordinator’s job description into the future 

will include revision of plans and/or practices and procedures developed in this MCONCQA 

compliance program as driven by MCONCQA initiative. 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

C. Other Regulatory Requirements/Suggestions 

1. Safety Committee 

If not already in place, a safety/accreditation committee provides an excellent vehicle to 

support ongoing training and program-related implementation issues. SUGGESTION 

2. Americans with Disabilities Act (Title III) Compliance 

An on-site facility and compliance audit, preparation of barrier removal plan and office policy 

and ADA awareness training for staff is required for all healthcare facilities. 

3. Controlled Substance Management Program 

An on-site audit of your facility’s degree of compliance with the Federal Controlled 

Substances Act, written recommendations for corrective measures and a complete training 

program and manual providing required protocols and documentation should be conducted for 

all applicable facilities. 

4. High Risk TB Exposure Control Plan 

A manual based on current CDC recommendations that includes a TB policy, screening and 

testing procedures? treatment? control measures, recordkeeping forms and the tools for 

performing a risk assessment should be created, and staff members trained on program 

components. May be required depending on facility type. 

5. Radiation Safety Plan 

A plan developed according to specific state laws that describes standard operating 

procedures, registration requirements, personal protective equipment and barrier 

requirements, radiation dose limits and monitoring, handling of regulated waste, and provides 

recordkeeping forms and required postings. May be required depending on facility type. 

6. Employee Policies Program 

Every facility should develop an Employee Handbook and employee policies covering 

benefits, work hours, vacations and holidays, sexual harassment, snow days, hiring, 

disciplinary actions and some 40 other employment related issues. Such a program has been 

demonstrated to deflect lawsuits and liability exposure. 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Regulatory & Accreditation Readiness Quick-test 

Does the facility have a written protocol for an Informed Consent 

process between the doctor and patient, clearly defining the criteria 

for when Informed Consent is warranted? 

Does the facility have a Chaperone Policy that defines when a 

chaperone should be offered to a patient? 

Does the facility have a Confidentiality Policy defining restrictions 

on utilizing answering machines when leaving messages for 

patients? 

Does the facility have a Hazard Communication/ Bloodborne 

Pathogens manual customized with facility-specific information? 

Does the facility have a written controlled substance (DEA) 

management program, including accounting controls? 

Does the facility have a written Americans with Disabilities Act 

Barrier Removal Plan? (required by law) 

Is there an eyewash, and is it properly mounted and accessible? 

Has industrial hygiene and x-ray monitoring been conducted? 

Does the facility have a written Employee Policies Manual, 

including harassment, workplace violence, and hscrimination? 

Does the facility have a written protocol for surface disinfection? 

Does the facility have a written TB Prevention Program 

Does the facility make Hepatitis vaccination available to all "at risk" 

employees, and is this program documented? 

Does the facility follow a formal, written Post-Exposure Evaluation 

and Follow-Up protocol for use in the event of an exposure incident? 

Does the office have MSDSs for every product in use, organized 

for quick access? (Generic, non specific MSDSs do not count!) 

Do all secondary containers have appropriate hazard labels, and 

does labeling system cross-reference with MSDS Book? 

Are fue and evacuation plans documented? 

Is on-sitejob-speciJc annual Staff Safety Training provided by a 

qualified instructor? (required annually by OSHA) 

5 Yes 

CI Yes 

Ci Yes 

5 Yes 

5 Yes 

01 Yes 

5 Yes 

Cl Yes 

Cl Yes 

CI Yes 

CI Yes 

CI Yes 

# Yes 

CI Yes 

5 Yes 

0 Yes 

CI Yes 

0 No 

Cl No 

5 No 

CI No 

5 No 

# No 

5 No 

5 No 

# No 

Cl No 

5 No 

CI No 

# No 

Cl No 

5 No 

CI No 

# No 
Patricia White 

MedSafe, Inc. 

Waltham, Massachusetts 

Butviciu J. White is a CertiJied Dental Assistant and President-elect of the American Dental 

Assistants Association, where has served for several years as trustee for the First District of the 

American Dental Assistants Association. With MedSafe, a provider of safety, risk management 

and regulatory consultation services, Pat is involved with the implementation of MedSafe ’s 

Regulatory Compliance Programs for the company’s healthcare organization clients. She can be 

contacted at MedSufe, Inc., 69 Hickory Drive, Waltham, Massachusetts 02451. Phone: 1-800- 

862-6675. Fax (781) 684-0525. E-mail: pwhite@medsafe.com. Web Page www.medsafe.com. 

‘i