A year before a Georgia chemical plant fire engulfed an Atlanta suburb in toxic gas this week, a federal watchdog agency issued a warning: the plant, and others like it, were not covered by regulations intended to prevent catastrophic chemical accidents.

Yet despite years of outcry from environmentalists, powerful chemical industry lobbyists have kept regulators from updating these rules to include these facilities, potentially leaving workers and communities across the country at greater risk of devastating toxic disasters.

Over the last five years, there have been hundreds of chemical accidents at facilities that are not covered by these regulations, watchdog groups have found.