2 
7. The accepted approach is outlined in paragraph 5 of GMAG Note 12, namely, 
that an individual assessment must be made in each case, taking into account 
the biological characteristics of the system and the physical characteristics 
of the plant combined with an appraisal of the competence of the management 
and the training and skill of the operators. This appraisal involves making 
a site visit. We regard this as being essential whereas I understand that 
this may present some difficulties for you. 
I note that in the first line of Section VII of your guidelines where it 
refers to " large-scale uses " your cite "the laboratory practices". This 
may account for some misunderstanding between us. We believe that the optimum 
move in scale is to go as directly as possible to the final industrial volume. 
We would be happy to go with our GMAG Note 12 and our check list to inspect any 
plant with fermenters of some thousands of litres capacity. 
I feel very strongly that our approach is correct and that it is a mistake to 
include use with manipulation as you and the EEC propose in your respective drafts. 
In your letter to Dr Gibson, you refer to the comments made by Dr Irving 
Johnson about levels of containment lower than "B2-LS" being approved in the UK for 
large scale work. You will appreciate that this comment is irrelevant but I share 
his misgivings about the "architectural curb" (VII - B -3 - b and VII - C - 3 - h). 
This requirement is unrealistic except for a scale of a few hundreds of litres 
whereas we must be planning for a scale of some thousands of litres. 
Yours sincerely, 
William Henderson 
Dr William Gartland, 
Director, Office of Recombinant DNA Activities, 
National Institute of Allergy & Infectious 
Diseases , 
Bethesda , 
Maryland, 
USA. 
[ 272 ] 
