How long after final cleaning can dust samples be collected?

The recommended period for collecting dust samples after final cleaning is typically set at 1 hour. This time frame allows for any remaining dust to settle sufficiently while minimizing the potential for contamination or disturbance of the surfaces that were just cleaned.

Collecting samples too soon, such as immediately following cleaning, may not provide an accurate representation of dust levels since the surfaces might still be disturbed and not reflective of the actual lead dust presence. Waiting for 30 minutes could still be too short, as dust might not have settled adequately, leading to misleading results. The 2-hour mark, while still an acceptable time frame, is often more than what is needed for optimal settling and could unnecessarily delay the sampling process. Thus, 1 hour strikes a balance between ensuring that the area is truly representative of post-cleaning conditions and allowing for practical sampling operations.