Contact time

Definition

The length of time a biocide or thermal treatment remains in lethal contact with organisms.

As HOCl fraction falls, chlorine programs become much more dependent on contact time, feed strategy, and residual persistence. For thermal treatment, kill depends on temperature and exposure time together, with higher temperatures shortening required contact time. Insufficient contact time lets stressed or sheltered organisms survive and resume activity.

Related concepts

Residual · Dormancy · Thermal disinfection

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