Frequently Asked Questions
What is a log reduction value (LRV)?
Log reduction value (LRV) measures how much a process reduces a microbial population. An LRV of 1 means 90% reduction (10-fold); LRV of 3 means 99.9% reduction (1,000-fold). It equals log10(initial count / final count).
How many log reductions are required for sterilization?
Sterilization is defined as a 10^-6 probability of a surviving organism (6-log reduction or Sterility Assurance Level of 10^-6). Disinfection standards vary: the EPA requires 3-log for Giardia and 4-log for viruses in drinking water.
What is the difference between log reduction and percent kill?
They express the same result in different units. A 99% kill equals a 2-log reduction; 99.9% equals 3-log; 99.99% equals 4-log. Log reduction is preferred in regulatory settings because the percentage scale compresses and obscures differences at high efficacy levels.
What is the difference between log reduction and D-value (decimal reduction time)?
Log reduction (LRV) is how many tenfold drops a treatment achieves overall, log10(N0/N). The D-value, or decimal reduction time, is the exposure time (or dose) a specific process needs to achieve one single log reduction of a given organism under set conditions. They are directly linked: total log reduction = exposure time / D-value. For example, an organism with a D-value of 2 minutes held for 10 minutes gives a 10 / 2 = 5-log reduction.
Provided by AllCalculators.io
Free online calculators for everyday. No registration required.
Estimates for informational purposes only.
Important Disclaimer: Estimates for informational purposes only.
This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.