Episode 287 is an 8‑minute technical training segment where Dr. Ayers explains how to calculate the minimum and maximum sampling times for air monitoring during chemical exposure assessments. He uses Hydrogen Chloride (HCl) as the practical example to walk listeners through the math and reasoning.
Dr. Ayers emphasizes that choosing the correct sampling time is essential because:
Too short a sample may fall below the analytical detection limit
Too long a sample may overload the media
Both errors can invalidate results and compromise compliance decisions
He explains how to determine the minimum time needed to collect enough contaminant mass for the lab to detect it reliably.
This depends on:
The analytical method’s detection limit
The expected concentration
The sampling flow rate
He then covers how to calculate the maximum allowable time before the sampling media becomes overloaded or saturated.
This depends on:
The media capacity
The chemical’s properties
The flow rate
Using HCl, Dr. Ayers demonstrates:
How to plug real numbers into the formulas
How to interpret the results
How to choose a sampling time that falls between the minimum and maximum limits
This example helps safety professionals apply the method to any chemical.
Proper sampling time is critical for valid, defensible exposure data.
Always calculate both minimum and maximum times before sampling.
Use real‑world examples (like HCl) to practice the math.
Good sampling strategy prevents wasted time, bad data, and compliance issues.
