Which statement best describes how a defensible sampling plan is established?

• A. Randomly picking surfaces without considering area.
• B. Sampling only during low-traffic times.
• C. Using a standardized sampling plan that defines surface areas and collection methods.
• D. Using only air samples to define clearance.

Answer: (C)

Establishing a defensible sampling plan hinges on using a standardized, documented approach that specifies exactly which surface areas will be sampled and how each sample will be collected. This creates consistency across samples, allows results to be repeated and reviewed, and supports clear, defensible decisions about clearance because every step—what to sample, where, with what tool, how much material to collect, and how it’s handled—follows the same procedure. Randomly picking surfaces without considering area introduces bias and gaps, making conclusions less defensible. Sampling only during low-traffic times addresses timing but not the scope or method, so results may not represent typical conditions. Relying on air samples alone misses surface contamination and cannot define clearance for many residues, whereas a defensible plan covers defined surface areas and validated collection methods.