During clearance testing, wipe samples should be collected from which surfaces?

During clearance testing, wipe samples should be collected from which surfaces?

• A. All surfaces in the area that could be contaminated
• B. Only high-touch surfaces
• C. Randomly chosen surfaces
• D. Only the most visible surfaces

Answer: (A)

Clearance testing aims to verify that residual lead dust is below the required limit on surfaces that could have been contaminated during work. Lead dust can settle on any surface in the area, not just the obvious ones, so sampling should cover all surfaces that could reasonably be contaminated. This provides a complete, representative assessment of cleanliness and protects occupants. Sampling only high-touch surfaces risks missing dust on floors, window sills, baseboards, and other surfaces that dust can settle on. Sampling only the most visible surfaces likewise can miss hidden contamination. Randomly chosen surfaces may not capture problem spots and may fail to represent the entire area. Therefore you collect wipe samples from all surfaces in the area that could be contaminated to ensure an accurate clearance determination.

Clearance testing aims to verify that residual lead dust is below the required limit on surfaces that could have been contaminated during work. Lead dust can settle on any surface in the area, not just the obvious ones, so sampling should cover all surfaces that could reasonably be contaminated. This provides a complete, representative assessment of cleanliness and protects occupants. Sampling only high-touch surfaces risks missing dust on floors, window sills, baseboards, and other surfaces that dust can settle on. Sampling only the most visible surfaces likewise can miss hidden contamination. Randomly chosen surfaces may not capture problem spots and may fail to represent the entire area. Therefore you collect wipe samples from all surfaces in the area that could be contaminated to ensure an accurate clearance determination.