Under the federal Emergency Planning and Community Right-to-Know Act of 1986 (EPCRA), affected companies must report on- and off-site disposal or other releases to the environment of more than 650 toxic chemicals. The 20th Annual Toxic Chemical Report documents reported releases of toxic chemicals in Illinois for calendar year 2006, the most recent data available. In 2006, 1,157 facilities in Illinois reported toxic chemical releases of 112,558,536 pounds, which is the 14th largest amount among states. The most common type of release was air emissions, accounting for approximately 33 percent of reported releases. The top five Illinois counties for reported toxic releases were: (1) Peoria; (2) Cook; (3) Madison; (4) Macon; and (5) Will. Total releases in 2006 decreased from 122,608,953 pounds reported for 2005. There have been substantial reductions in Illinois and nationally since reporting began in 1988. Although it is difficult to compare annual data because of changes to the reporting requirements over the years, the downward trend in releases is apparent. For example, using a 1988 baseline, which only includes the chemicals and industries that were subject to reporting in 1988, releases in Illinois have declined from nearly 132 million pounds in 1988 to about 54 million pounds in 2006. Using a 1998 baseline, which includes chemicals and industries added to the reporting requirements from 1988 through 1998, releases declined from approximately 166 million pounds in 1998 to 109 million pounds annually in 2006.