The cleaning and sterilization of milk bottles

Abstract

The results just described for Greater London compare very favourably with those of similar surveys carried out in the United States by Hopkins & Kelly (1919), Smith (1923), and Layson, Huffer & Brannon (1936) (see also Report, 1934). The figures recorded in Table 7 show that approximately 50% of bottles from the large, the small rotary, and the steam sterilization plants conformed to a standard of less than 600 colonies per pint bottle, or approximately 1 colony per ml. capacity.The figures for the small rotary plants were not so good as for the large plants, there being a greater proportion of high counts among these. The same was even truer of the steam sterilization plants, in which about a quarter of the bottles were grossly contaminated. The results with the plants using hand-washing only were bad, none of them falling below the 2500 mark.The general conclusions to be drawn from this survey are that equally good results may be obtained in large or in small rotary plants relying on treatment with hot caustic detergent as in plants employing steam sterilization, and that the uniformly best results are obtained in properly designed and operated plants of the spray type.