Removal Technology

Most of the mercury released into the wastewater stream leaving the dental unit is in the form of amalgam particulate. However, a significant quantity of mercury is in the "soluble form" (< 0.45 microns) and in high enough concentrations to violate discharge limits for some local Publicly Owned Treatment Works (POTWs). Amalgam separating devices currently marketed to remediate this problem are certified using an ISO standard (ISO 11143) that focuses on percent particle removal
(> 95%) utilizing a standard amalgam sample suspended in water. However, the regulations governing the discharge of metals into the wastewater stream are framed in terms of concentrations and load.

The United States Environmental Protection agency (US EPA) has instituted the Environmental Technology Verification Program (ETV) to verify the performance of commercial technologies. The US EPA Office of Research and Development and NSF International, an independent, not-for-profit organization, have published a protocol for the evaluation of amalgam separators. This protocol looks at efficiency as a function of mercury concentrations as opposed to percent particle removal. There are numerous "amalgam separating" devices available to dentists, but particle separation may not be enough to satisfy local regulators. Dentists need to be aware of this issue before purchasing expensive devices that may not satisfy the discharge requirements of POTWs.

The following is a list of just a few of the amalgam separating systems (also known as pretreatment systems) available in the marketplace. This list of commercially available products does not imply endorsement.

AB Dental Trends, Rasch 890 Amalgam Separator
Air Techniques, Inc.
Nalco, Inc. Polymers N8701 (NALMET®) and N8186 (ULTRION®)
Pure Water Development, L.L.C. – METASYS Group
Rebec Separators
SolmeteX Separators
Sultan Healthcare Separator Systems