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Determination of the probability of one or more cans containing one viable organism after commercial sterilisation.
Replace the test values with your data to use the calculator.
Mass of product in can (grams)    
Initial spore load per gram    
Batch size used for control e.g. 1000 cans    
D*121C value of target micro-organism (minutes)    
Equivalency of heat process to time at 121C ** (minutes)    
There is a probability of 1 can (s) in a population of 100000000 cans containing
one viable micro-organism. This may cause spoilage and/or a public health hazard.
* Decimal reduction time, D, is the time taken to destroy 90% of the organisms at  
a particular temperature. Temperature used is written as a subscript e.g. D*121C. The D value shown
is within the range for spores of Clostridium botulinum. Note, thermophiles have much higher D values.
** Time at the temperature used to determine the D value is used. This time is expressed
as the equivalence of total time at this temperature.  
CAUTION. This calculator is an educational tool and is not warranted in any way. It is not a substitute for
employing a qualified food technologist. The values obtained require interpretation by a qualified person. .
See F calculator  


How to cite this article

Mullan, W.M.A. (2007) [On-line] UK: Available: Accessed:

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