436 ENGINEERING ASPECTS OF PASTEURIZATION 



cording device shall indicate a temperature and time in excess of 140° F. and 30 minutes, 

 equal to the safety margin recommended by the [accepted agency making the official tests] 

 for the apparatus in question, and provided the apparatus is operated in accordance with 

 the directions recommended by the [accepted agency making the ofi&cial tests]. 



It is apparent that these definitions require detailed knowledge by the health 

 officer secured from his own engineering tests or complete published information from 

 some official agency such as the United States Public Health Service. 



Any general agreement on the question of what temperature should be required 

 for pasteurization, whether 142°, 145°, or some other temperature, will probably not 

 be accomplished until health officials are satisfied that engineering defects have been 

 eliminated from the commercial pasteurizing equipment under their jurisdiction. 

 Many believe that for the present the maximum factor of safety obtainable without 

 serious cream-line reduction is desirable to offset partially the temperature drops oc- 

 curring in portions of milk not receiving the full temperature and time of holding due 

 to the defects in construction or operation of the pasteurizing equipment. 



When these defects have been corrected, it is possible that a considerable portion 

 of those now favoring 145° F. will be willing to consider a legal definition which will 

 permit the use of 142° or 143° F. as a minimum temperature for pasteurizing milk 

 when held for thirty minutes in apparatus approved by an accepted official agency. 



