Not unlike other jurisdictions in the United States, schools in the State of Maryland are essentially run as county-wide districts. In 2010, after years in the planning stages, a growing suburban county was finally constructing eight new elementary schools. The district had suffered over the last two decades through the expense and delays of
asbestos remediation and control. Accordingly, they had adopted a proactive approach to any new renovation or construction activity. Their program covered a wide range of 29CFR1910 & 1926 (OSHA) issues to protect school employees and contractors, as well as 40CFR763 (EPA/AHERA) issues in a comprehensive O&M plan.
Part of this proactive approach required construction contractors to have their materials approved as asbestos-fre before incorporating them into the building. Usually, this meant that the architectural and engineering
contractors would have to pre-screen the materials through the manufacturer; a quick scan of a material’s ingredients listed on an MSDS would usually suffice. In addition, some sort of certification letter or document
from construction purchaser or manufacturer was required before a building material was approved.
Back to Basics, Asbestos 101:
Obviously, thousands of building materials might be involved in a large school structure. Asbestos was intentionally formulated into thousands of such products over the last few generations due to its unique properties. As the unintended consequences of asbestos in these materials became known, and especially after billions of litigation
dollars and tragic deaths resulted, the purposeful use of asbestos as an additive in materials diminished significantly. For older buildings that contain these asbestos-laden products, regulators have strict systems to control their release and removal. Again, this study looks at the new construction dilemma.
Asbestos minerals are still mined throughout the world for their use in products. In 2009, the United States imported 1500 metric tons of these minerals. Worldwide production increased over 2 million metric tons in 2009 after a several-year decline. The primary exporters of Russia, South Africa, Brazil, Canada, and China have a long, profitable history of asbestos mining. The health consequences of asbestos are coming to light despite some attempts to soften the news of exposure and disease. These minerals, like many similar base and raw materials, are heterogeneous in composition and require several degrees of processing before being pure enough to meet standards of grade required for material formulations.
The gypsum mineral used in sheetrock/drywall products may have other calcium-based minerals like limestone associated with the deposit that is sometimes separated and sometimes not separated out of the manufacturing
process. This is often true for dolomite – a calcium/magnesium based- mineral used in hundreds of products. Yet dolomite can have asbestos “contamination.” That is to say, the geologic, geothermal, and chemical processes involved in the creation of dolomite also produce a close cousin: tremolite. Asbestiform tremolite is a regulated hazardous mineral by US EPA. These minerals occur in populations that may have a distribution of both non-regulated, non-asbestiform tremolite, and the asbestiform and regulated variety.
Now, About That School…
In 2010, iATL was contracted by an environmental engineering consultant firm in Maryland to provide testing of materials before inclusion into the construction process. Many times, the building materials were just assumed to be non-asbestos-containing material (ACM) and were incorporated into the structure. With the school’s and construction
stakeholders’ fingers crossed, nearly all the materials were found to be as advertised — non-ACM…nearly. Out of hundreds of new floor tiles, particular batches of a range of pink to purple pastel colored tiles repeatedly tested as trace and <1% by volume of tremolite asbestos by the US EPA 600 R93/116 Method for Determination of Asbestos in Bulk building Materials. The testing used the prescribed Polarized Light Microscopy (PLM) technique. Two tile samples of a particular hue had PLM analytical results ranging from slightly under to slightly over the 1% magic threshold value. A disclaimer required by US EPA on such flooring material reports indicated the recommendation of a more advanced testing technique employing Transmission Electron Microscopy (TEM) by the ELAP 198.4 analytical method.
The former method used the analytical technique of PLM to look at optical properties (several) that must be evident before qualifying the suspect fibers as regulated asbestos mineral. The quantification of the fibers is a whole other matter not discussed here. The latter method (TEM by ELAP 198.4) utilized the principles of gravimetric reduction (weighing sub-samples before and after thermally removing organic binders and acid washing interfering carbonates away) to leave only inorganic (usually mineral) residue. The residue revealed a population of mostly non-asbestiform and unregulated tremolite.
By itself, the non-regulated fraction represented about 1-3% of the total make-up of those suspect floor tile samples. Interestingly enough, the product’s raw material MSDS revealed dolomite and “1% tremolite.” There was also a smaller population in this subset of truly asbestiform, and therefore regulated, tremolite asbestos. The population was calculated to range from <0.1 — 0.8%… close to the threshold.
We reported that the analytical techniques and methods requested were up against their own inherent limits. There are more sophisticated techniques outlined in US EPA 600 R93/116 Appendix C (??) to establish a fibrosity index of the suspect building material. This high level analysis would determine conclusively whether or not the samples were ACM. The environmental consultant and the school agreed with this approach. To prevent
any bias or systematic error, it was further recommended that the samples be sent to Dr. Eric Chatfield, a widely recognized international expert in asbestos laboratory
At this stage, the floor tile manufacturer and associated sub-contractors, raw material/mineral suppliers, and their testing laboratory were informed of the situation. Construction that involved floor tile installation was immediately stopped. All parties gathered to discuss the laboratory findings, to have the efficacy of the analytical methods demonstrated, and to discuss the strategy outlined.
The stakeholders that gathered shared only one thing in common – a few newly manufactured floor tile samples were causing problems with their plans. The parties also shared a common theme we have observed over the last
28 years – there are various definitions of asbestos. Seen graphically below, these similar yet disparate definitions of asbestos do not clarify — they cloud the efforts of all involved to be ‘on the same page.’ This is used for better or worse in asbestos litigation. Rigorous Results:
It was agreed upon that the factors outlined above were “in play” and that our abundant and robust analyses, based upon strict analytical protocols, were, in fact, correct. Dr. Chatfield’s results were presented (see graphic summation of one such sample below) and accepted by all parties. These, too, concluded that the floor tiles were under the 1% threshold for tremolite asbestos.