How many blank samples should be submitted per job?

How many blank samples should be submitted per job?

• A. One per job tested
• B. Two per job
• C. Three per job
• D. Four per job

Answer: (A)

Blank samples provide a contamination-free baseline for the entire sampling and analysis process. Submitting one blank per job tested ensures you can spot any contamination introduced during field collection or lab analysis that could affect that specific job’s results. The blank goes through the same steps as real samples, so any lead detected in the blank indicates a process issue rather than actual lead on the job site. This per-job control is the most efficient way to verify accuracy without unnecessary extra costs. Having more than one blank per job doesn’t materially improve the ability to detect job-specific contamination and would add unnecessary expense. If the blank shows any lead, you’d investigate the sampling or analytical procedures for that job before relying on the job’s results.

Blank samples provide a contamination-free baseline for the entire sampling and analysis process. Submitting one blank per job tested ensures you can spot any contamination introduced during field collection or lab analysis that could affect that specific job’s results. The blank goes through the same steps as real samples, so any lead detected in the blank indicates a process issue rather than actual lead on the job site. This per-job control is the most efficient way to verify accuracy without unnecessary extra costs. Having more than one blank per job doesn’t materially improve the ability to detect job-specific contamination and would add unnecessary expense. If the blank shows any lead, you’d investigate the sampling or analytical procedures for that job before relying on the job’s results.