EPA Lowers Limits on Lead in Dust on Floors and Windowsills

A new final rule announced by EPA on June 21 will revise the federal limits for lead in dust on floors and windowsills. The rule will lower the agency’s dust-lead hazard standards from 40 µg/ft² to 10 µg/ft² on floors and from 250 µg/ft² to 100 µg/ft² on windowsills. The new limits will apply to houses built before 1978 and to buildings where children spend many hours, such as daycare centers and kindergarten facilities. A pre-publication version of the EPA rule is available on the agency’s website (PDF). The rule will become effective 180 days after publication in the Federal Register.

The current limits on lead in dust on floors and windowsills have been in place since 2001. At that time, the Centers for Disease Control and Prevention identified a blood-lead level in children of 10 µg/dL as a “level of concern.” CDC’s current guidance states that no safe blood-lead level in children has been identified and calls for public health measures to be initiated at a blood-lead level in children of 5 µg/dL. EPA cited this change in CDC’s guidance as a factor in its decision to issue tighter standards.

Another factor was a December 2017 order by a federal appeals court that required EPA to issue new lead standards within 90 days, a deadline that was later extended. At the time of the court’s ruling, the agency had been working on the standards for about six years and had said it would need six more years to complete them, according to NPR.

While the final rule lowers EPA’s dust-lead hazard standards, it does not change the agency’s clearance standards used to determine whether renovated homes are safe for re-occupancy. The clearance standards will remain 40 µg/ft² for floors, 250 µg/ft² for windowsills, and 400 µg/ft² for window troughs.

According to Derek Popp, a member of the AIHA Proficiency Analytical Testing Programs Board, lead-based paint professionals could confront situations where lead dust on floors and windowsills in a renovated home meets EPA’s clearance standards but not the new hazard standards.

“The field professional needs to know what standard is going to be applied,” Popp said. “For example, if [a home] is going to be re-occupied as housing managed by a [Department of Housing and Urban Development] grantee, it would need to meet the HUD clearance standard with levels lower than the EPA clearance levels.”

The final rule also changes requirements for recognition of environmental lead laboratories under the agency’s National Lead Laboratory Accreditation Program. Under these new requirements, a laboratory must achieve a reporting limit (the minimum quantity of lead that can be quantified to a specified accuracy) of equal to or less than 10 µg/ft² in wipe samples and a method detection limit (the minimum concentration of lead that has a 99 percent probability of being identified as greater than zero) equal to or less than one half of the laboratory’s reporting limit.

“Many laboratories may have trouble meeting this lower reportable limit,” Popp said. “The EPA is advising changing the sampling area recommended by the laboratory or making changes to sample preparation or analytical methods.”

More information on EPA’s new standards is available on the agency’s website.