What sampling method is commonly used for wipe sampling in lead clearance?

• A. Air sampling using sorbent tubes
• B. Wipe sampling using pre-moistened wipes and standardized surface area templates (e.g., 100 cm2) followed by laboratory analysis (ICP-MS or AAS)
• C. Visual inspection of dust deposition
• D. Swab sampling with dry swabs only

Answer: (B)

Wipe sampling quantifies residual lead dust on surfaces after cleaning, which is exactly what lead clearance tests aim to demonstrate. Using pre-moistened wipes improves pickup and transfer of lead particles from the surface into the wipe, making the measurement more reliable than dry materials. Sampling over a defined surface area, such as 100 cm2, standardizes how much surface is tested and ensures results can be compared across rooms and jobs while aligning with guidelines for clearance. After collection, the wipe is analyzed in a laboratory with ICP-MS or AAS, which provide precise, sensitive measurements of lead present in the sample. This combination gives a quantitative assessment of surface contamination and whether it meets clearance criteria. In contrast, air sampling looks at airborne lead, visual inspection is subjective and non-quantitative, and dry swabs tend to be less effective at removing dust, leading to less reliable results.