What are the dimensions of the minimum window sample?

• A. 4 inches by 4 inches
• B. 2 inches by 8 inches
• C. 1 inch by 16 inches
• D. 3 inches by 6 inches

Answer: (B)

In lead dust sampling, the area and shape of the wipe sample are standardized so results are comparable and representative. For a minimum window sample, the recommended size is a rectangular 2 inches by 8 inches, which equals 16 square inches. This long, narrow strip fits typical window sills and provides enough surface to capture dust without being so large that wiping becomes impractical, helping ensure consistent collection across samples.

The 2 by 8 inch rectangle is preferred because it aligns with how dust tends to accumulate along a window edge and across the sill, making the sample more representative of the area of concern. Other shapes or dimensions either deviate from the standard rectangle used in the protocol, or are less practical to wipe evenly in the field, even if their area is similar.