Lead-based paint abatement thresholds measured by XRF are reported in which unit?

Lead-based paint abatement thresholds measured by XRF are reported in which unit?

• A. mg/cm2
• B. ppm
• C. percent
• D. mg/m2

Answer: (A)

XRF readings for lead-based paint thresholds are expressed as a surface loading: how many milligrams of lead are present on each square centimeter of the painted surface. This per-area measurement matches the way regulatory thresholds are defined (for example, a surface with about 1 mg of lead per cm^2 is considered lead-based paint for abatement purposes). Using mg/cm^2 is different from concentration-by-weight measures like ppm or percent, which describe how much lead is in the paint by weight rather than how much lead sits on a given area. While mg/m^2 is also a mass-per-area unit, the conventional and regulatory standard in XRF-based assessments uses mg/cm^2, reflecting surface loading on typical small-scale test areas and device calibration.

XRF readings for lead-based paint thresholds are expressed as a surface loading: how many milligrams of lead are present on each square centimeter of the painted surface. This per-area measurement matches the way regulatory thresholds are defined (for example, a surface with about 1 mg of lead per cm^2 is considered lead-based paint for abatement purposes).

Using mg/cm^2 is different from concentration-by-weight measures like ppm or percent, which describe how much lead is in the paint by weight rather than how much lead sits on a given area. While mg/m^2 is also a mass-per-area unit, the conventional and regulatory standard in XRF-based assessments uses mg/cm^2, reflecting surface loading on typical small-scale test areas and device calibration.