What is a key purpose of a surface wipe (frottis)?

• A. To provide a semi-quantitative evaluation of lead contamination on surfaces, PPE, or tools
• B. To measure the surface's moisture content
• C. To check the color under lights
• D. To determine substrate porosity

Answer: (D)

Surface wipe sampling is about checking surfaces and equipment for residues of hazardous contaminants. The main purpose is to collect a sample with a wipe and obtain a semi-quantitative estimate of how much contaminant—such as lead—is present on a surface, PPE, or tools. This helps determine exposure risk, the effectiveness of cleaning, and whether controls are needed.

Moisture content, color under lighting, and substrate porosity are not evaluated by a wipe test. Those properties require other methods: moisture is measured with a moisture meter, color is assessed visually or with colorimetric tests, and porosity is determined by porosimetry or absorption tests, not by surface wipe sampling.