What is the maximum holding time for preserved BOD5 samples?

The maximum holding time for preserved BOD5 (Biochemical Oxygen Demand over a 5-day period) samples is 2 days. This time frame is critical because the BOD5 test measures the amount of oxygen consumed by microorganisms in the sample over a specified period, which is typically 5 days at 20 degrees Celsius.

If the samples are not analyzed within this 2-day holding period, there is a risk that the microbial population and the organic material in the sample could change due to continued biological activity or degradation. This can lead to inaccuracies in measuring the actual BOD5, compromising the reliability of the test results. It is essential to process samples as quickly as possible to ensure that they accurately reflect the conditions of the wastewater being tested. If samples are held longer than 2 days, the results may not be representative of the original sample's characteristics.