Healthy Indoors Magazine
Issue link: https://hi.healthyindoors.com/i/1216998
24 | February 2020 sis. The same is true of Aroclors that have been subjected to environmental degradation ("weathering") or degradation by treatment technologies. Such weathered multi-compo- nent mixtures may have significant differences in peak pat- terns compared to those of Aroclor standards. Only expe- rienced and certified laboratories should be utilized for this analysis. Most states require certification for the analysis of PCBs in caulk, therefore you should check with the labo- ratory to confirm that they hold the proper state certification for this analysis. Case Study Due to the unique nature of caulk potentially containing both asbestos and PCBs, it was decided to conduct a brief and informal study to investigate this concept more fully. At EMSL Analytical, Inc., we receive numerous samples of caulk for the analysis of asbestos and PCBs, however we rarely receive requests to perform both asbestos and PCB analysis on the same sample. I thought this was an import- ant issue that required more study as this concept unique- ly applies to the building science industry. Thirty-one (31) caulk samples were pulled randomly from EMSL's sample repository in which PCB analysis was already performed. These samples were then blindly submitted to EMSL's as- bestos laboratory for analysis of asbestos via TEM follow- ing gravimetric reduction sample preparation procedures. Results Of the thirty-one (31) samples, more than half were posi- tive for PCBs, with fifteen (15) samples (48%) containing concentrations of over 50 parts per million (ppm), which categorizes these samples as regulated and the caulk as an unauthorized use by the US EPA. Nine (9) of these samples showed PCB results over 10,000 ppm, with the highest result of 92,000 ppm which translates to 9.2% PCB containing caulk. Fourteen (14) samples were non-detect- ed for PCBs (45%). All PCB positive samples were found to contain Aroclor - 1254 with one sample containing both Aroclors - 1248 and 1254. Of the thirty-one (31) samples, eleven (11) samples were found to contain asbestos (35%), with six (6) samples containing greater than 1% asbestos, thereby meeting the US EPA definition of Asbestos Containing Material (ACM). Twenty (20) samples (65%) were non-detected for asbes- tos. The highest concentration of asbestos was reported at 7.8% Chrysotile asbestos. Eight (8) of the eleven (11) samples were found to contain Chrysotile asbestos, two (2) samples were found to contain Anthophyllite asbestos and one (1) sample was found to contain both Chrysotile and Anthophyllite asbestos. Overall when comparing both results on a sample by removed. Caulk containing PCBs at levels < 50 ppm may remain in place. PCBs in caulk are known to contaminate adjacent building materials (e.g. masonry, wood, concrete) as well as soil surrounding the building. Therefore, any sur- rounding building material that is contaminated by > 50 ppm PCB-containing caulk, such as through leaching of PCBs is considered PCB remediation waste and must be cleaned up using 40 CFR ยง 761.61. Please note individual state regulations may be more stringent (CT as one example) and should be thoroughly researched prior to interpreting results for compliance. For asbestos analysis, it is strongly recommended that the sample be first subjected to gravimetric reduction (which includes high temperature ashing and acid reduc- tion) as caulk is a non-friable organically bound (NOB) ma- terial. The organic matrix can coat and obscure the asbes- tos fibers and without this procedure to remove this organic matrix, there is an increased likelihood of false negative results. Analysis can be first performed by Polarized Light Microscopy (PLM) following the EPA/600/R-93/116 method. Furthermore, due to the potential for small asbestos fiber sizes below the resolution of the light microscope, all PLM asbestos results of non-detect to <1% should be further confirmed by Transmission Electron Microscopy (TEM). Some states in the US (NY as one example) require gravi- metric reduction and TEM confirmation for NOB materials, therefore when sampling, one should check with the labo- ratory to confirm individual state requirements. For the analysis of caulk for the presence of PCBs, the test method to be utilized is the US EPA SW-846-8082A which is performed by Gas Chromatography using an Elec- tron Capture Detector (ECD). This method may be used to determine the concentration of polychlorinated biphe- nyls (PCBs) as Aroclors. Aroclors are multi-component mixtures. When samples contain more than one Aroclor, a higher level of analyst expertise is required to attain accept- able accuracy levels for qualitative and quantitative analy- Example of Proper Amount of Caulk Material Collected for Analysis