Which EPA clearance value is used for floors?

Which EPA clearance value is used for floors?

• A. 400 ug/ft2
• B. 40 ug/ft2
• C. 250 ug/ft2
• D. 10 ug/ft2

Answer: (B)

Clearance values after lead dust cleanup depend on the surface being tested, because lead dust behaves differently on different materials. For floors, the EPA uses 40 micrograms of lead per square foot as the clearance value. This lower threshold reflects the high exposure risk from dust on floor surfaces that people walk on and may track into living spaces, so the target is a very clean floor. In contrast, window sills have a higher limit (about 250 μg/ft2) and window troughs are higher still (about 400 μg/ft2) because those surfaces accumulate dust differently and are less likely to be contacted as much as floors. A value like 10 μg/ft2 isn’t a standard floor clearance level. So, the correct floor clearance value is 40 μg/ft2.

Clearance values after lead dust cleanup depend on the surface being tested, because lead dust behaves differently on different materials. For floors, the EPA uses 40 micrograms of lead per square foot as the clearance value. This lower threshold reflects the high exposure risk from dust on floor surfaces that people walk on and may track into living spaces, so the target is a very clean floor. In contrast, window sills have a higher limit (about 250 μg/ft2) and window troughs are higher still (about 400 μg/ft2) because those surfaces accumulate dust differently and are less likely to be contacted as much as floors. A value like 10 μg/ft2 isn’t a standard floor clearance level. So, the correct floor clearance value is 40 μg/ft2.