Field screening of a sample is used to determine if the sample requires laboratory analysis.

• A. Is optional
• B. Determines whether to submit for lab analysis
• C. Replaces laboratory testing
• D. Provides final results

Answer: (B)

Field screening is an on-site, rapid assessment used to triage samples. Its purpose is to decide whether a sample should be submitted to a laboratory for confirmatory analysis. It is not optional and does not replace laboratory testing; screening helps prioritize which samples need lab work and which can be handled without it. Importantly, screening results are presumptive and not final—lab analysis is required to confirm composition and concentrations.