56 
This would be a space in which a laboratory worker could put on a totally 
enclosed, positive pressure suit that would allow then introduction into a 
containment room for the conduct of experiments that could not be confined 
to the more traditional glove box systems. This suit approach has been 
used successfully in the past at Fort Detrick. It is being proposed and 
constructed at the Center for Disease Control for work with lassa virus, 
and our information to date suggests that this is a very positive and capable 
way of protecting the laboratory worker from potentially risky experiments. 
I think that basically covers the major changes and considerations that 
went into the revision to the physical containment section. 
DR. FREDRICKSON: Thank you, Dr. Barkley. Will you remain there for 
just a moment? 
Note that the physical containment section has been reorganized, and 
it incorporates a good deal of the philosophy and guidance derived from an 
interaction between NIH and international experts in physical containment, 
clearly because the thrust of all of this activity must be toward comity 
and eventually at least parity in terms of definitions throughout the world, 
where these kinds of activities are going on. 
The most notable clarifications then have been made in matters of 
equipment and special facility design. There have been some mandatory 
"shalls" substituted for "shoulds." 
The EMBO telegram which you have received does contain some refer- 
ences to physical containment. Dr. Tooze felt that it might be better if 
he dealt with some of those under biological containment. I think, as it 
seems appropriate, we are going to have Dr. Barkley, and other commentators 
who wish us to look at those EMBO recommendations, comment upon them rela- 
tive to the proposed revisions for the NIH Guidelines. There are still 
some differences, certainly, in a few definitions, that will remain. 
I wonder now if the Committee has any questions. 
Sir John? 
SIR JOHN KENDREW: I would like to ask about the very last point that 
you made, concerning the positive pressure suits. In the draft revisions, 
as you have said, you give these as an optional system. Now, of course, it 
does represent a very different philosophy in achieving high levels of 
containment, and I think there are a lot of people in a lot of countries 
who are contemplating constructing such facilities. They really now have 
to think out which approach they are going to adopt. Obviously it affects 
the costs, it affects a whole number of aspects of the thing. 
I must say that I had rather hoped that your Committee would find it- 
self in a position to make some more positive recommendations here, rather 
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