Gas-powered lawnmowers will need to be cleaner, due to new rules from the Environmental Protection Agency.

Adopted Thursday, the new regulation calls for a 35 percent reduction in emissions from new lawn and garden equipment using engines of less than 25 horsepower.

The mandate takes effect in 2011 and is designed to save 190 million gallons of gas annually.

Small engine manufacturers had opposed the regulation for years. But not even lawnmowers are exempt from air pollution rules.