BS ISO 4831:2006

1   Scope This International Standard gives general guidelines for the detection and the enumeration of coliforms . It is applicable to

       -  products intended for human consumption and for the feeding of animals, and 
   
   
     
       -  environmental samples in the area of food production and food handling. 
   
 

Enumeration is carried out by calculation of the most probable number (MPN) after incubation in a liquid medium at 30 °C or 37 °C.

   NOTE  The temperature is subject to agreement between the parties concerned. In the case of milk and milk products, the temperature of incubation is 30 °C. 

This enumeration method is applicable when the number sought is expected to be in the range 1 to 100 per millilitre or per gram of test sample. A limitation on the applicability of this International Standard is imposed by the susceptibility of the method to a large degree of variability. The information given in Clause 11 provides guidance on the applicability of the method and on the interpretation of the results.