Thus, after an exposure time of 1 D, only 10% of the organisms originally present in a microbial colony would remain.
The term originated in assessments of microbes' thermal resistance and in thermal death time analysis; however, it now has analogous uses in other microbial resistance and death rate applications, such as for ethylene oxide and radiation processing.
Use of D-values is based on the assumption that the procedure in question causes the number of living microorganisms to decay exponentially.
[2] In the context of thermal analysis it is typical practice to subscript the "D" with an indication of temperature.
D-values are sometimes used to express a disinfectant's efficiency in reducing the number of microbes present in a given environment.