Washington, D.C. ? Joe Hall was unequivocal about what he expects new emissions standards for lawn mowers will mean for his small lawn-care business.

“It’s going to hurt me bad,” Hall said Friday while comparing prices on new lawn mowers at a Home Depot in Waldorf, Md. “The prices are going to go through the roof.”

An Environmental Protection Agency regulation announced Thursday requires a 35 percent emissions reduction in new gas-powered lawn and garden equipment of less than 25 horsepower beginning in 2011. All gas-powered recreational boats must reduce emissions by 70 percent one year earlier.

The EPA said the pollution reductions will eliminate hundreds of thousands of tons of hydrocarbons and nitrogen oxide, which produce smog and can lead to respiratory problems.

Implementing the changes, which EPA officials say will save 190 million gallons of gas and 300 lives each year, is expected to cost $236 million.

The brunt of that price tag will fall directly on consumers, analysts and manufacturers said. Looking to buy a lawn mower in three years? Plan to pay about 18 percent more than today, the California Air Resources Board estimates. Boat buyers will probably see prices increase nearly that much, retailers and distributors said.

“There are definitely going to be some additional costs incurred and passed on,” said Laura Timm, a spokeswoman for Briggs & Stratton, a Milwaukee-based manufacturer of small engines for lawn mowers and other equipment.

Timm said that the changes could involve adding catalytic converters like those designed to reduce emissions from cars to smaller engines but that an engine redesign could accomplish the same goal.

Briggs & Stratton initially opposed the EPA regulations, in part because of the projected cost increase, but Timm said company leaders worked extensively with government officials and are satisfied with the wording of the announcement.

But several distributors that buy engines from such companies as Briggs & Stratton, as well as retailers and individual consumers, find the cost increases far less palatable.

Hall said he replaces each of his company’s lawn mowers every few years, so an 18 percent price increase could deeply cut in his profits.

“I’ve already been dealing with paying $4 for gas to fill the things, and now I’m going to pay more for the machines, too,” Hall said.

Bill Holliman, store manager at Scott’s Turf Equipment & Supply in Manassas, Va., agreed that the cost increase could hit some consumers hard but does not expect his sales to decrease. People will still need their lawns mowed, he said, so they will have to buy mowers or pay a lawn-care company that has a fleet. Because older models of lawn tools will be grandfathered in under the new rules, he will continue to sell the outdated, less-expensive equipment as long as possible, he said.

“If they’re a tree-hugger, they’ll pay extra for the environmentally friendly one,” he said. “And if they think it’s all a bunch of bunk, they’ll take the cheaper one.”

Not every company is bemoaning the EPA rules. Black and Decker, based in Towson, Md., sells a variety of lawn and gardening equipment in addition to its trademark power tools. It’s benefited from the move toward environmentally friendly gardening because all of its lawn mowers, hedge trimmers and edgers run on electricity.

“As the regulations tighten,” said Roger Young, a spokesman for Black and Decker, “we think there’s some growth potential there.”