The U.S. Environmental Protection Agency (EPA) is currently evaluating potential applicability criteria for glycol dehydrator air emission controls. To assist this evaluation, the American Petroleum Institute (API) commissioned TRJ Environmental to develop a methodology to estimate benzene exposures and associated risks under representative emission conditions.<\/p>\n
This report is divided into seven sections. Section 2 describes preliminary risk assessment analyses performed by EPA prior to the startup of this project. The analyses included dispersion model runs using 348 meteorological stations and the application of Monte Carlo modeling techniques to the dispersion model results. Section 2 also summarizes a series of exploratory analyses in which the SCREEN3 dispersion model was applied to eight emission scenarios identified as representative of typical operating conditions. The model produced an estimate of the maximum benzene concentration at each of 10 distances considered in the earlier EPA dispersion model runs. Section 3 presents the results of a special analysis in which Version 2 of the Industrial Source Complex dispersion model (ISC2) was applied to 45 meteorological stations selected by API as representative of areas where glycol dehydrators were likely to be located. After completion of the special analysis, API and EPA jointly developed a set of 24 emission scenarios to be used in subsequent dispersion modeling runs.<\/p>\n
Section 4 describes the 24 emission scenarios and presents the results of applying the ISC2 model to 348 meteorological stations under each scenario. Researchers statistically analyzed these results and developed a spreadsheet model for estimating outdoor benzene concentrations as a function of source-to-receptor distance and emission scenario. Section 4 describes the model and provides sample outputs.<\/p>\n
Section 5 describes development of a PC-based model incorporating the spreadsheet and a Monte Carlo routine combining the outdoor benzene concentrations with randomly generated exposure factors to determine lifetime risk distributions. Section 6 presents a simplified method for estimating the 50th and 95th percentiles of these lifetime risk distributions. Section 7 discusses the limitations of the proposed modeling approach and provides recommendations for further research. Section 7 also describes a method by which model estimates can be used to determine whether or not a specific glycol dehydrator should be subject to controls for reducing benzene emissions.<\/p>\n","protected":false},"excerpt":{"rendered":"
A Methodology for Estimating Incremental Benzene Exposures and Risks Associated with Glycol Dehydrators<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n API<\/b><\/a><\/td>\n 1997<\/td>\n 80<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":487735,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[2642],"product_tag":[],"class_list":{"0":"post-487726","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-api","8":"first","9":"instock","10":"sold-individually","11":"shipping-taxable","12":"purchasable","13":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/487726","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/487735"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=487726"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=487726"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=487726"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}