Mercury contamination in dental offices that remove or replace amalgam fillings is a serious matter that can negatively affect the health of employees. It’s no wonder dentists are choosing to become certified in the Safe Mercury Amalgam Removal Technique (SMART). This safety protocol developed by The International Academy of Oral Medicine and Toxicology aims to protect staff and patients by reducing the amount of mercury generated during the amalgam removal process.

The properties of elemental mercury

Consider the properties of mercury vapor for a second… colorless, odorless and invisible. In order to reduce mercury exposure to employees and patients, biological mercury-safe dentists implement a number of engineering controls. However, because of all the safety precautions in place, those who practice mercury-safe dentistry might be easily lulled into a false sense of security thinking they have eliminated all mercury exposures.

Identifying Areas of Mercury Contamination

I can hear some dentists now asking… “Doesn’t the inter-oral suction and oral aerosol vacuum system suck up all the mercury vapor and particles? The short answer is no. No matter how diligent one is at implementing the various engineering controls to capture mercury during amalgam removal, the unfortunate reality is there will be some mercury particulate that escapes collection.  Also, don’t expect to see this mercury contamination on your PPE or surfaces as the vast majority of the particles are too small to see with the human eye. The mercury particles can be carried into other parts of the dental office on clothing and by air flow. Thus it is vital to identify where the escaped mercury accumulates, how to test for it and how to safely clean it.

Check out the video above for more details from study author Mark Richardson, PhD, who has published extensively about mercury.

How much dental mercury escapes collection

The mercury particulate that escapes collection will contribute to the mercury contamination in your office by continuing to off gas into the dental operatory. So how much mercury escapes you ask? Well, like most things, it depends on a number of factors, such as how many amalgams fillings are removed in a given session, how many OSHA engineering controls have been properly implemented and the personal technique of the dentist.

As you will read below, even with all engineering controls and proper technique the levels of mercury vapor from escaped particles can create mercury contamination that exceed occupational safety levels.

Where does the escaped mercury accumulate?

Since, the removal of an amalgam filling generates a cloud of micron and sub-micron sized mercury particulate that is suspended in air for roughly 10 minutes, any surface in the area of the amalgam removal is a potential place for it to land and must be thoroughly tested.

Here is some information from SMART certified dentist Matthew Young, DDS, FIAOMT, about how he discovered mercury contamination in his dental operatory and how he safely cleaned the mercury.

Mercury-Safe Biological Dentist Matthew Young, DDS, FIAOMT

Learn more about Dr. Young and his mercury-safe dental practice by watching this clip from the Oscar qualifying film, Evidence of Harm, a documentary about the hazards of mercury dental fillings to patients, staff and the global environment.

Identifying a source of mercury contamination

When the mercury particulate was first measured in our clinic with a spectrophotometer from Mercury Instruments USA, I was surprised at the amount of mercury vapor that was released from a very small sample.

I asked my assistant to wipe the linoleum floor with a dry Swiffer pad one day after removing several amalgams from a patient’s mouth (with all of the SMART safety controls in place). We put the dry Swiffer in a quart sized Baggie and the mercury vapor analyzer measured well over 200% of what OSHA allows in a single day at work.

Cleaning mercury contamination

We then applied four or five squirts of Mercon spray to the dry Swiffer pad after removing the next set of fillings and mopped the floor with that. Mercon spray is another mercury neutralizing solution that mitigates the toxic effects of the particulate.

We then remeasured the amount of mercury out gassing from the particulate that hit the floor and it was shown to be close to our baseline readings.

How you can test for mercury contamination in your dental office

There are a number of ways to test which surfaces in your operatory might be accumulating and off gassing mercury. We offer a week long rental of a Mercury Tracker 3000, a portable mercury vapor analyzer from Mercury Instruments USA. With this portable measuring device, one can go to various points through-out their office to test for mercury vapor levels. The Mercury Tracker 3000 will display real time results of mercury levels.

Be aware that while mercury vapor is heavier than air it is still very easy to move around. Where mercury vapor resides is influenced by air flow, such as the opening and closing of doors and even walking through a room.  We recommend donning your PPE and respirator while measuring for mercury contamination.

ImageNamePriceBuyShort Description
mercury tracker 3000 lid off
Mercury Tracker 3000XS - Portable Mercury Vapor Analyzer ONE WEEK RENTAL$699.00

ONE WEEK RENTAL of a Mercury Tracker 3000XS portable mercury detection system which is a lightweight, compact and rugged instrument for measuring the mercury concentration in air and other gases. Product rental ships only to continental United States in a hard shell pelican case with extra batteries and accessories.

Additionally, we also offer Mercury Surface Wipes to detect mercury contamination from particulate matter that has settled onto floors, counter tops and equipment (such as the extended hose of the oral aerosol vacuum). The Mercury Surface Wipe will change color depending upon the amount of mercury it picks up. You can compare the color on the mercury wipe to the corresponding color on the Mercury Color Comparator, which has a color dial to indicate the mercury level. Ideally a dentist would use only one Mercury Surface Wipe per surface to get an accurate level from that specific surface.

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chemteq mercury wipe 306
Mercury Detection Surface Wipes (5 pack)$65.00 – or subscribe and get up to 5% off

Choose a subscription plan:

The Mercury ChemWipe 306 is a colorimetric surface wipe designed to provide real-time indication of the presence of trace amounts of mercury and mercury II compounds on surfaces. The Mercury ChemWipe is selective and sensitive. The unique design of the ChemWipe provides uniform color change formation enabling user to quantify chemical contamination using the color comparator.

chemteq mercury comparator 306-6000
Mercury Color Comparator$55.00

After using the Mercury Surface Wipes, use the Mercury Color Comparator to quantify the mass of mercury collected on the Mercury Surface Wipe

How to properly clean your dental office of mercury particles

After finding where mercury has accumulated, it is important to wipe your dental equipment, counter tops and surfaces with a mercury decontaminant. This should be done roughly 10 – 15 minutes after the amalgam removal. As that is approximately how long the cloud of mercury particulate will take to settle onto surfaces. Respirators, PPE and thick nitrile gloves should be worn when using Mercury Wipes to clean up mercury particulate.

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showa n-dex 8 mil nitrile gloves box 3
8 mil Nitrile Gloves, Disposable, Lightly Powdered, 9.5" Long, Blue - 50/box$14.00

SHOWA N-DEX 8 Mil, 9.5″ Long, Disposable, Lightly Powdered, Nitrile Exam Gloves, Blue, Box of 50 Gloves

Proper disposal of mercury contaminated items

One should endeavor to follow all city, state and federals laws regarding the disposal of mercury. When using the Mercury Wipes the mercury is bound to proprietary ingredient of the mercury wipe.

Other considerations

Also, please be aware that any disposable items used during amalgam removal will be contaminated with mercury and will continue to off gas, so make sure those items are in a sealed container.

Your experience with identifying and cleaning mercury contamination

We’d like to hear of your experiences with identifying and cleaning mercury that has escaped collection or if you have any questions, please leave a comment below.