US EPA tightens emission standards for small non-road engines
The US EPA has finalised additional exhaust emission reduction standards for non-handheld engines primarily used in lawn mowers, garden tractors and turf equipment.
The new standards, effective in 2001, will reduce hydrocarbons, which produce ground-level ozone, and nitrogen oxides by 59 percent. The current standard calls for a 32 percent reduction when fully phased in.
The emission reductions will provide significant national benefits because equipment is used regularly in summer months when ozone levels are highest.
Small spark ignition engines produce about one tenth of the nation’s mobile source hydrocarbons (HC) emissions and are the largest single HC contributor to non-road sources.
The standards will be phased in between 2001 and 2007 to provide a smooth transition of engine design and technologies such as automotive-style overhead valve engines. The newer technology also will reduce fuel consumption by approximately 15 percent.
The rule includes requirements to ensure that engines continue to comply with the standards throughout their useful life. Other provisions include a certification averaging, banking, and trading program, and special compliance allowances for very low emitting engines.
Considerations to ease or delay the impact on low volume engines and equipment also are provided in the rule.