WASHINGTON — The U.S. EPA has issued new, tougher standards used to define dangerous levels of lead in old paint, dust and soil. The standards will affect guidelines followed by state and local government agencies in seeking remedial actions to reduce lead hazards, and also will apply to other federal lead provisions such as the EPA’s real-estate disclosure requirements. Those rules affect sellers and renters of housing.

The agency said the standards also will provide landlords, parents and child-care providers with specific levels on which to make informed decisions regarding lead found in their homes, yards, or play areas.

Under the new standards, lead is considered a hazard if there are greater than 40 micrograms (mg) of lead in dust per square foot on floors; 250 mg of lead in dust per square foot on interior window sills, and 400 parts per million (ppm) of lead in bare soil in children’s play areas or a 1,200-ppm average for bare soil in the rest of the yard. The new standards go into effect immediately, an EPA spokesman said.

Previously, the standards had been 100 mg per square foot for floors; 500 mg/square foot for interior window sills, and 800 mg/square foot for window troughs. The standard for soil had been 2,000 mg per gram of soil, with a level of 400 mg per gram of soil for children’s play areas.

The EPA said the new standards would be listed at the website www.epa.gov/lead. More information also is available through the National Lead Information Center at 800/424.LEAD (5323).