The concept of decimal reduction time allows the probability of the
survival of spores to be predicted. For example, if a process is sufficiently
effective to produce 10 decimal reductions in the microbial population then, if a
canned food which is to be sterilised contained initially 1010 spores per can, the
final population would be one spore per can. Alternatively, for an initial
population of 105 spores per can, the final population would be 10-5 spores per
can. This latter figure is interpreted to mean that one can in 105 is likely to
contain a spore. Such a process is referred to as a 10D process.