Contact Time

Duration of substance contact

Contact time is typically used to describe the duration a solvent, cleaning agent, or sanitizer must remain on a surface for its cleaning properties to be effective. During cleaning, contact time is synonymous with "time" which is defined in PDA TR29, Points to Consider for Validation, as "the length of time for the cycle step". During the cycle step the contact time is determined either directly through meassuring the time elapsed or indirectly by expressing the contact time in relation to the volume decreasing over the course of a rinse. The contact time required during cleaning may be shortened depending on other actions during the cleaning such as agitation of soils.