Final dust wipe sample results must be reported in what units?

Final dust wipe sample results must be reported in what units?

• A. ug/ft2
• B. mg/m2
• C. ng/cm2
• D. parts per million

Answer: (A)

Dust wipe results are reported as mass per area to express how much lead is loading onto a surface. After wiping a defined area, the lab reports the lead mass in micrograms, and you divide by the wiped area to get the result in micrograms per square foot. This unit directly ties to the hazard thresholds used for dust on floors and windowsills, which are defined per square foot. Using per-area loading also keeps results comparable across surfaces of different sizes. Other units like mg/m^2 or ng/cm^2 represent the same idea in different metric systems, but the standard reporting unit in this context is micrograms per square foot.

Dust wipe results are reported as mass per area to express how much lead is loading onto a surface. After wiping a defined area, the lab reports the lead mass in micrograms, and you divide by the wiped area to get the result in micrograms per square foot. This unit directly ties to the hazard thresholds used for dust on floors and windowsills, which are defined per square foot. Using per-area loading also keeps results comparable across surfaces of different sizes. Other units like mg/m^2 or ng/cm^2 represent the same idea in different metric systems, but the standard reporting unit in this context is micrograms per square foot.