Japanese–English glossary
Log reduction value (LRV)
Also called log reduction factor
対数減少値（LRV）taisū genshōchi (LRV)
Also written 対数除去率、対数除去、クリアランス
A measure of how much a process step reduces virus or another contaminant, expressed as the base-10 logarithm of the ratio between the amount before and the amount after the step. An LRV of 4 means a 10,000-fold reduction. Values from steps that work by different mechanisms are added to give total process clearance, which must leave a margin over the potential virus load. Japanese documents also call it the log reduction rate, or simply clearance.