Landmark Environmental, Inc. (Landmark) has received questions from our clients in the Architecture, Engineering, and Construction (AEC) industry regarding the risks and assessment of mercury flooring. We have assisted clients when facing hazardous mercury flooring, a rubber-like polyurethane floor utilizing a Phenyl Mercuric Acetate (PMA) catalyst, which has been installed in areas such as multipurpose rooms, cafeterias, gyms, auditoriums, stages, and indoor and outdoor tracks since the 1960s. This type of flooring can emit vapors, posing health risks, especially in poorly ventilated areas. Mercury vapors are odorless and colorless, making them difficult to detect without proper testing.
We thought it might be helpful to share with you our knowledge of mercury flooring assessment, management and methods in occupancy and renovation of buildings, as well as disposal and waste management of mercury flooring in the event one of your projects might include this material.
Original Mercury Flooring
Abatement in Progress
Mercury Flooring
OVERVIEW
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Assessment of Safety: Safety assessments include air sampling for mercury vapors and bulk sampling of the flooring material. Off-gassing is a significant concern, as mercury vapors can persist for years and decades, especially if the flooring is damaged or deteriorated.
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Manufacturers: Notable manufacturers of mercury flooring include 3M (Tartan® floors), American Biltrite Rubber Co. Inc., and Amtico Rubber Flooring.
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Materials and Layers: Mercury flooring typically consists of rubber-like polyurethane, often layered over concrete or a shock-absorbing cushion. The flooring may be hidden under other flooring materials due to renovations over time. Flooring installed over mercury flooring can include carpet, vinyl or laminate flooring, or porcelain stoneware.
MANAGEMENT & METHODS: MERCURY FLOORING IN OCCUPANCY AND RENOVATION OF BUILDINGS
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Inventory: Visual inspections can identify locations of potential mercury flooring, such as gymnasiums, laboratories, and multipurpose rooms, and review construction documents (if available) to locate mercury flooring. Inspection may include intrusive investigation through flooring layers if mercury flooring is suspected based on the area's use and history.
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Testing and Assessment: Sampling of the mercury flooring can determine mercury content, and sampling and analysis are performed either by direct-reading instruments or by an accredited laboratory. Air quality is sampled to measure the concentration of mercury vapors. After air sampling, a hazard assessment can be conducted to evaluate the potential health risks associated with the detected mercury levels by comparing the measured concentrations to established Occupational Exposure Limits (OELs). Established safe levels of mercury vapor in the air are very low.
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Mitigation Measures: If mercury levels are identified, mitigation measures such as improved ventilation, sealing the flooring, or removal of the mercury-containing flooring may be recommended.
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Worker and Occupant Safety: During construction or renovation, ensure proper ventilation and use Personal Protective Equipment (PPE) to minimize exposure to mercury vapors.
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Occupational Exposure: OSHA standards for mercury exposure must be followed, including air contaminant limits and respiratory protection.
DISPOSAL & WASTE MANAGEMENT
Disposal Considerations: If mercury flooring is removed, the level of mercury content can affect waste packaging and disposal requirements. Elevated mercury content may require specialized disposal. A Toxicity Characteristic Leaching Procedure (TCLP) sample is required to determine whether the mercury flooring must be disposed in a hazardous waste landfill.
If you have any questions regarding IAQ assessments or if Landmark can provide any assistance, don't hesitate to contact Matt Roberts (mroberts@landmarkenviro.com).
QUESTIONS
If you have any questions regarding mercury flooring or if Landmark can provide any assistance, don't hesitate to contact Landmark President Matt Roberts.