So-called small spark ignition engines produce approximately 10 per cent of the US’s mobile source hydrocarbon emissions, and are the single largest contributor after road-based sources.
The EPA originally proposed further emission controls in January 1998, but the Agency has now re-submitted the “phase 2” controls, citing “rapid advances in emission control technologies for handheld engines”. If the re-submitted controls are passed they will lead, according to the EPA, to a 78 per cent reduction in the emissions beyond the current, phase 1controls.
The re-submitted requirements are similar to those recently adopted by California, in that they ensure that engines continue to comply with emission standards throughout their life.