WASHINGTON (AP) _ Polluting engine-powered mowers that are a staple of suburban lawn care would become much cleaner under emission limits being proposed Tuesday by government regulators.
The proposal follows a long-running dispute between California Democratic Sen. Dianne Feinstein and Missouri Republican Sen. Kit Bond, who sought to block the change in order to protect a small-engine maker in his home state, Briggs & Stratton.
Engines under 50 horsepower, which are mostly used to power walk-behind and riding mowers, account for up to 10 percent of summertime smog emissions from mobile sources in some parts of the country.
The Environmental Protection Agency has been considering a proposal that would cut smog-forming emissions from the engines by roughly 40 percent. This would likely be achieved by installing catalytic converters that reduce pollution from exhaust.
The final proposed rule was to be released Tuesday afternoon, an agency spokeswoman said.
Adding catalytic converters will make mowers more expensive, according to the California Air Resources Board, and some in the industry resisted the change.
California already has enacted the rule. The nation's most populous state has unique authority under the Clean Air Act to establish its own pollution rules if it's granted a federal waiver, and California got the small-engine waiver last December.
Bond had initially sought to block California from instituting its regulation but backed off under pressure from Feinstein. He did succeed in blocking other states from being able to copy California's rule, something the Clean Air Act normally allows. Instead, he required EPA to write the national standard being proposed Tuesday.
Bond had questioned whether mowers with catalytic converters could spark fires, but an EPA study last year found there was no safety problem.
``The bottom line is these standards are long overdue but they will be absolutely essential in order to help many parts of the country meet public-health standards,'' said Frank O'Donnell, president of Clean Air Watch, an environmental advocacy group.