You are here:
A REPORT ON USING FORWARD LOOKING INFRARED RADIATION (FLIR) TECHNOLOGY AS AN EFFECTIVE PCE/TCE SCREENING TOOL FOR VAPOR INTRUSION SAMPLING
Eppler, D., D. Ferguson, M. Torres, D. Young, AND R. Venkatapathy. A REPORT ON USING FORWARD LOOKING INFRARED RADIATION (FLIR) TECHNOLOGY AS AN EFFECTIVE PCE/TCE SCREENING TOOL FOR VAPOR INTRUSION SAMPLING. U.S. Environmental Protection Agency, Washington, DC, EPA/600/X-18/348, 2018.
The goal was to provide an economical method of screening a potential vapor intrusion site for sampling locations to minimize sampling error and expense. The research evaluated the use of FLIR technology as a pre-sample screening tool to find sample locations to minimize the expense of more costly sampling technologies by reducing the number of samples, and obtaining samples that will be more accurate in defining the vapor intrusion problems. Vapor intrusion of toxic chemicals has the potential to significantly affect inhabitants of indoor environments. Minimizing sampling error and sampling cost by effective pre-sample screening provides for more accurate assessment of potential exposure yielding greater understanding of potential risk.
The information in this document is from a collaborative effort between the U.S. EPA, Region 6 Superfund Division and the Office of Research and Development, National Risk Management Research Laboratory. Research was conducted at the US EPA Region 6 Addison Texas Facility. The findings represent an evaluation of forward looking infrared radiation (FLIR) camera technology as a tool in screening of locations that suffer from tetrachloroethylene (PCE; International Union of Pure and Applied Chemistry (IUPAC) name: tetrachloroethene) and trichloroethylene (TCE; IUPAC name: trichloroethene) vapor intrusion (VI) into indoor air spaces prior to using costlier conventional sampling technologies in residential and commercial/industrial settings, where the potential for PCE and TCE short-term health effects are more difficult to assess. Research summarized in this report may provide a novel and innovative method to yield expeditious PCE and TCE screening levels to improve risk management decisions, which for far too long have relied on decades old sampling and analysis methods. There has been no use of the FLIR technology at the EPA to determine whether the instrument has screening capabilities in VI to indoor air risk assessment work and monitoring to assess and verify the performance and effectiveness of the remediation systems and interim measures. PCE and TCE are industrial chemicals that may be released into the air, water and soil in locations close to their manufacture or use. Humans may be exposed to PCE and TCE by breathing air contaminated with PCE/TCE vapors (inhalation), drinking contaminated water (ingestion), or through activities such as showering (dermal/inhalation). One of the major sources of exposure to PCE and TCE is through VI from PCE and TCE contaminated ground water and soils into buildings through gaps or cracks in the building foundation, through porous concrete or through open doors and windows. The detection capability or the sensitivity of a camera system is highly dependent on the concentration of gas in the plume and the cross-sectional length of the plume along the camera axis. Since the testing laboratory did not have the means to increase the plume size and the amount of gas for testing purposes was limited, the path length of a gas plume was artificially increased by capturing the gas (or liquids) in a plastic bottle. Under this scenario, the two cameras could detect ammonia and TCE vapors inside the plastic bottle, and were able to differentiate chemical vapors from a plastic bottle containing air. The ability to detect vapors under this so-called “static” scenario will be useful in situations such as confined spaces where a lack of air movement will cause the gas to remain in place long enough to be detected by an IR camera. Though this study was not successful in detecting PCE and TCE vapor intrusions at both the worker and residential air exposure scenarios; this research was successful in demonstrating the capability of FLIR technology to safely detect gas leaks from a location relatively far from the source. In addition, the study was useful in determining the effect of flow rates of gas plumes and cross-sectional length of the plume with respect to the camera axis on a camera’s detection capabilities. However, based on their IR spectra and information provided by the manufacturer, detection of gases such as methane, propane and butane; gasoline fumes; solvents such as benzene and methylene chloride; and common water pollutants such as trihalomethanes are well within the capabilities of the two experimental camera systems. Other means to increase detector sensitivity include using a camera lens with a longer focal length, and controlling environmental factors such as wind, humidity and background.
Record Details:Record Type: DOCUMENT (PUBLISHED REPORT/REPORT)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
LAND AND MATERIALS MANAGEMENT DIVISION
LIFE CYCLE AND DECISION SUPPORT BRANCH