What is the hold time required for Biochemical Oxygen Demand (BOD) testing?

The hold time for Biochemical Oxygen Demand (BOD) testing is crucial to obtaining accurate results that reflect the sample's oxygen demand over time. BOD testing typically requires that the samples be analyzed within 48 hours of collection to ensure that the biological processes within the sample accurately represent its oxygen-demanding characteristics.

During this 48-hour period, the sample is kept at a temperature of around 20 degrees Celsius, which is the standard for BOD testing and conditions that mimic the natural environment where microbial activity occurs. Beyond this timeframe, degradation of organic materials or changes in microbial populations can alter the sample's characteristics, leading to inaccurate results.

Thus, adhering to the 48-hour hold time is fundamental in ensuring the integrity of the sample and the reliability of the BOD measurements.