Healthy Indoors Magazine - USA Edition

34 | April 2020 We have seen the mini-can sampling system used to find out the degree of hydrocarbon contamination in a building adjacent to a service station. The investigator found a gasoline-type odor in their workplace one morning and used TO-15 to help determine the source of the odor as well as the concentration. TO-15 was able to show that the contamination was indeed gasoline and possibly from the adjacent service station. TO-15 was also able to show that the air was also contaminated in upstairs office areas where the odor was not as obvious. The 6-L sampling system was used to find out what was causing an acrid odor on the side of a complainant's home that receives the early morning sun. Some paints contain biocides designed to suppress mold growth. These paints can off-gas mercaptans which have 'dirty sock' odor. TO-15 helped identify the odor compounds. The mini-can sampling system has been used to perform workplace exposure measurements for various compounds in a pesticide plant. The plant owners were concerned with ambient air concentrations of carbon tetrachloride among other commonly used solvents in that industry. A facility manager responsible for air quality in a region adjacent to a wastewater treatment plant used a special- ized version of TO-15. The laboratory performed SIM (sin- gle ion monitoring) analysis using the 6-L sampling system for TO-15. With SIM, the laboratory was able to achieve detection limits 10-100 times lower than with conventional full-scan analysis. Conclusion The advances in sampling for volatile organic compounds have made it simple and more effective than in the past. No longer should the investigator worry about calibrating their pumps and finding a power source. Pull out one of the new the canister technologies, open a valve and your sampling is underway. The laboratory takes care of the hard part of analyzing the sample. TO-15 analysis should be consid- ered in your next indoor air quality study. Questions? — please contact Jason Dobranic, PhD at: 800-220-3675. their current policies. If you want to own your own equip- ment, the sampling canisters can cost between $500-750 and regulators can average between $700-800 each. TO-15 Analytical Considerations The analytical equipment used to perform the TO-15 analy- sis constitutes a rather large capital investment. The instru- ment and related sampling equipment can cost between $150 and $250K before any analysis is even started. The sophistication of the laboratory's analytical equipment has a direct correlation as to the usefulness and the quality of the analytical data produced. Your project needs may re- quire state of the art instrumentation and methodologies. Consult with your laboratory and ask how they can service your project needs. Your laboratory can provide several types of TO-15 anal- yses. The TO-15 analysis, as written by the EPA, refers to a specific list of 62 regulated compounds (Table 1). These compounds may or may not be important for your project. The list was developed to support the Clean Air Act. Sever- al amendments have been added to the Clean Air Act that include several subsets of additional compounds. Check with your lab to inquire which list they report and their re- porting limits of detection. Your particular project may only require a subset of the full list, which may result in analysis cost savings. If your project does not require TO-15's full list and you want to know, 'what is in my air sample?', you can take a different approach. You can specify the TO-15 full list and ask the laboratory to do a non-target compound library search. This will give you a listing of up to 10-20 extra compounds that are not targets. These compounds are referred to tentatively identified compounds (TICs) and are, as their title states, tentative. This analysis will cost more but can provide you with information that best serves your project goals. TO-15 Applications and Projects TO-15 can be used for most IAQ applications. You can use it for odor identification, general investigations, and clear- ance. TO-15 can also be used in mold investigations by identifying MVOCs. MVOC concentrations were found to be higher in damp buildings with associated complaints than in non-complaint buildings. If mold spores were not detected in an air sample but odors or other signs point towards mold growth in a building, then MVOC sampling may be warrant- ed. MVOCs were found to pass through poly sheeting while spores cannot. 3-methyl-1-butanol, 2-hexanone and 2-hep- tone have been used as fungal growth indicators. i

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