Wood Products MACT Risk Assessment, 2003 Environmental Conference Proceedings

ENSR International was contracted by the AF&PA to develop a national-scale risk assessment for wood products facilities based on historical site-specific air toxics dispersion modeling studies. The study established that refined dispersion modeling could be used to identify facilities that do not pose a risk, such that the application of additional MACT controls would not result in appreciable health benefits. The AF&PA study is consistent with EPA’s proposed risk-based approach to Wood Products MACT. The study involved several steps, including: 1) collection and review of air toxics modeling studies, 2) review of modeling data, 3) model sensitivity analyses, 4) extrapolation of modeled formaldehyde emissions to other HAPs, 5) toxicological review, and 6) extension of findings to a nationwide risk assessment. The study concluded that a MACT rule with the option to conduct site-specific risk assessments will ensure that only those sources with significant risks will need to take actions to mitigate those risks.