D-value
Pronunciation: DEE-val-yoo
The time or dose required to achieve a one-log reduction (90% kill) of a microbial population under specified conditions.
Full Definition
D-value is a fundamental parameter in sterilization science representing the decimal reduction time. It quantifies the resistance of microorganisms to a particular sterilization method under defined conditions of temperature, pressure, or chemical concentration. In surgical instrument reprocessing, D-values are essential for calculating sterilization cycle parameters and ensuring adequate microbial kill. Different microorganisms have different D-values, with bacterial spores typically showing the highest resistance.
Usage
Usage note: Always capitalize 'D' and hyphenate. Not interchangeable with Z-value (temperature sensitivity) or F-value (lethality).
In Context
- "The D-value for Geobacillus stearothermophilus at 121°C was used to validate the steam sterilization cycle." — Sterilization validation protocol
- "Calculating appropriate exposure times requires knowing the D-value of the most resistant organism present." — Technical training manual