Self-reporting as a system of monitoring or enforcement has been shown to work particularly well in the USA where the Emergency Planning and Community Right-to-Know Act of 1986 required some 20,000 industries to report on their annual emissions of 320 potentially carcinogenic compounds. Industries immediately started making significant reductions in their emissions, even though they had at that time not been legally required to do so. Monsanto reduced its emissions by 39% by 1992, DuPont made a 63% reduction by 1993 and Dow Chemical plans a 50% reduction by 1995.