In the sampling technique, how many times should the wipe process be repeated?

In the sampling technique, how many times should the wipe process be repeated?

• A. 1 time
• B. 3 times
• C. 4 times
• D. 5 times

Answer: (B)

A wipe sample aims to capture a representative amount of lead dust from a defined surface. Dust isn’t spread evenly, and a single wipe often leaves behind dust that’s adhered or tucked into crevices. Repeating the wipe process helps pull out more of what’s actually there, reducing sampling error and giving a more accurate result. Three passes is the standard approach because the first wipe removes the readily accessible dust, and the subsequent passes pick up what remains, providing a more complete sample for lab analysis. Using only one wipe risks underestimating lead levels, while adding more than three passes generally doesn’t add meaningful new information and adds time and handling steps. Following three passes aligns with common field practices for clearance testing and ensures there’s enough material for reliable lab measurement.

A wipe sample aims to capture a representative amount of lead dust from a defined surface. Dust isn’t spread evenly, and a single wipe often leaves behind dust that’s adhered or tucked into crevices. Repeating the wipe process helps pull out more of what’s actually there, reducing sampling error and giving a more accurate result. Three passes is the standard approach because the first wipe removes the readily accessible dust, and the subsequent passes pick up what remains, providing a more complete sample for lab analysis. Using only one wipe risks underestimating lead levels, while adding more than three passes generally doesn’t add meaningful new information and adds time and handling steps. Following three passes aligns with common field practices for clearance testing and ensures there’s enough material for reliable lab measurement.