In contrast to the reduction of SO2 emissions, Inco's Superstack stands out in North America in its arsenic, nickel and lead emissions to the atmosphere. Using data compiled by the Commission for Environmental Cooperation, Inco alone accounts for 20% of all of the arsenic emitted in North America, 13% of the lead and 30% of the nickel. Although it is not strictly fair to compare a nickel-copper smelter to a lead smelter, by so doing one can get an idea of how poor the containment of lead is at Copper Cliff. In 1998, Inco emitted 146.7 tonnes of lead at Copper Cliff with a smelter production of 238,500 tonnes of nickel-copper matte. The EPA regulations in the United States require a primary lead smelter to limit emissions of lead to 3.0 gm per tonne of product. With this emission factor, Copper Cliff would be required to limit emissions of lead to approximately 1 tonne per year, demonstrating that the actual emission is about 150 times greater than allowed by US regulations for a lead smelter. Even with the 85% reduction postulated by Hatch, Inco would still emit 10 tonnes per year of lead, or four times the amount allowed by the EPA for a lead smelter.