Westmont, NJ, October 9th, 2009
Last week the U.S. Environmental Protection Agency (EPA) warned that hundreds of schools may have cancer-causing PCBs in caulk around windows and doors. This announcement has caught the attention of school districts across the country.
Asbestos caulking was widely used in the construction industry as a sealant, adhesive and as a patching material for cracks, seams and gaps in construction. Caulk as a construction material is widely used in all types of construction and asbestos-containing caulk was a highly ubiquitous substance.
Before safety rulings made its inclusion in construction materials illegal in the late 1970s, caulk manufacturers often used asbestos due to its beneficial fire resistance, strength and insulative properties. Before the 1970s, all types of asbestos, including Amphibole asbestos, were used in caulk formulas. Some caulks can be close to 100 percent asbestos, however most caulks contained 25% asbestos. After the 1970s, the predominant type of asbestos in caulk compounds was Chrysotile.
When first applied in its semi-liquid state, it was essentially as harmless as any other caulking material. However, over time and especially with exposure to the weather, air, and other environmental elements, caulking of any material breaks down and becomes brittle. As the material naturally degrades small asbestos fibers may be released into the air, especially when caulking is used around window or door seams which are subject to disturbance from vibration and air erosion.
Caulk samples containing more than one percent (1%) asbestos is considered a Category I Nonfriable Regulated Asbestos Containing Material (RACM) by the US EPA NESHAP (1990). Caulk presents a difficult analytical challenge to asbestos laboratories due to the presence of organic matrix materials due to the problem of coating and obscuring asbestos fibers present with opaque matter which can inhibit detection, yielding a false negative result. For this reason, several regulatory agencies, including the US EPA and NYS ELAP, recommend matrix modification steps to improve the ability of the laboratory in detecting asbestos in an organic matrix such as caulk. The gravimetric reduction preparation technique as described in EPA/600/R-93/116 section 2.3, should be followed for caulk samples followed by analysis via Polarized Light Microscopy (PLM). If the PLM results yield concentrations of one percent (1%) or less asbestos, then the sample should then proceed to analysis via Transmission Electron Microscopy (TEM).
“EMSL encourages schools to have PCB and Asbestos testing performed in their facilities,” reported Joe Frasca, Executive Vice President at EMSL Analytical. “Last year EMSL became one of a few select laboratories to hold radon certifications in all 50 states for analyzing samples and we are here to help school districts provide a safe environment for their students and faculty.”
EMSL Analytical, a leader in providing asbestos and pcb testing laboratory services and products can be reached at 1-800-220-3675 (East Coast) and 1-866-798-1089 (West Coast)
About EMSL Analytical, Inc.
EMSL Analytical is a nationally recognized and locally focused provider of environmental and industrial hygiene services and products to professionals and the general public. The company has an extensive list of accreditations from leading organizations as well as state and federal regulating bodies.
