If a sampling result is non-detect, what is a reasonable next step?

If a sampling result is non-detect, what is a reasonable next step?

• A. Resampling to confirm exposure levels and reassess controls
• B. Ignore and assume compliance
• C. Immediately declare compliance with the PEL
• D. Increase sampling rate indefinitely

Answer: (A)

When a sampling result is non-detect, the concentration is below the method’s limit of detection, which doesn’t prove there is no exposure or that it’s safely below the limit. The reasonable next step is to resample to obtain a quantitative exposure estimate and to reassess the controls. By collecting additional data—potentially with a more sensitive method, longer sampling durations, or different times/locations—you gain a clearer picture of actual exposure and the confidence that it truly stays under the permissible limit. This helps determine whether current controls are sufficient or if improvements are needed. Ignoring the result, declaring immediate compliance, or endlessly increasing sampling without a plan aren’t appropriate. Non-detect does not automatically equal compliance, and a practical, targeted follow-up sampling plan provides the needed footing to judge exposure and control effectiveness.

When a sampling result is non-detect, the concentration is below the method’s limit of detection, which doesn’t prove there is no exposure or that it’s safely below the limit. The reasonable next step is to resample to obtain a quantitative exposure estimate and to reassess the controls. By collecting additional data—potentially with a more sensitive method, longer sampling durations, or different times/locations—you gain a clearer picture of actual exposure and the confidence that it truly stays under the permissible limit. This helps determine whether current controls are sufficient or if improvements are needed.

Ignoring the result, declaring immediate compliance, or endlessly increasing sampling without a plan aren’t appropriate. Non-detect does not automatically equal compliance, and a practical, targeted follow-up sampling plan provides the needed footing to judge exposure and control effectiveness.