Day 106 - 23 Mar 95 - Page 52


     
     1
     2   Q.   I see that, but that only means the number of samples to be
     3        taken?
     4        A.  That is right.  That is the core of your sampling plan,
     5        the number of samples you take and also the way you take
     6        them.
     7
     8   Q.   Where do I see the way you take them?
     9        A.  Well, there is elsewhere, and I do not think it will be
    10        in -----
    11
    12   Q.   I can see on table 19 it has test APC, no doubt if anyone
    13        bothered to ask you you could explain to me what that was,
    14        and I can see method reference 118.  I do not, do I, maybe
    15        I do but I have missed it, see any reference to the test or
    16        method reference on page 38 in tab 3?
    17        A.  At the moment, my Lord, we have not got as far as
    18        actually doing the test; we are talking about the sampling
    19        plan.  This essentially sets out the bones of the sampling
    20        plan.  One assumes that those -- well I have my own -----
    21
    22   Q.   Do you know what APC and 118 means on page 91?  Page 90,
    23        aerobic plate counts is APC.
    24        A.  Yes.
    25
    26   Q.   What is the 118?
    27        A.  That presumably is a reference elsewhere in the book to
    28        the precise methodology in determining the -----
    29
    30   Q.   Yes, that is what I had assumed.
    31        A.  Which of course we do not have.
    32
    33   Q.   But we have no equivalent, for instance, just to take an
    34        example, next to E.coli on page 38, do we?
    35        A.  The first aerobic mesophile bacteria is essentially the
    36        APC, so that is to which it relates.
    37
    38   Q.   I see that.
    39        A.  The others are looking at specifics, one is E.coli.  It
    40        does not say it is 0157; I assume it is not 0157 but E.coli
    41        in general because I understand from elsewhere the criteria
    42        for 0157 is nil, hence since N is 500, one assumes it means
    43        E.coli in general.  Then specific pathogens, clostridium
    44        perfringens, staphylococci and salmonella.  Now what I was
    45        saying is that N for a sampling plan for determining the
    46        presence of predicted levels of salmonella particularly,
    47        and certainly E.coli 0157, is by no means adequate.  The
    48        basis of the sampling programme for specific pathogens has
    49        been set out and is widely known within the industry and is
    50        used routinely by the Ministry of Agriculture Fisheries and 
    51        Food.  The numbers of samples relate to your expectations 
    52        of the level of infection. 
    53
    54        The working criteria, the criteria I have worked with many
    55        times, are basically worked on salmonella to a probability,
    56        a 95 per cent probability of finding salmonella, i.e. a one
    57        in 20 chance of missing it, where the infection level in
    58        the population is 5 per cent or more.  Now where the
    59        population ----
    60

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