57 
than simply putting up the positive pressure suits as an option, but with- 
out actually coming out with recommendations saying which is better under 
which circumstances. Now, it may be simply that one hasn't got enough exper- 
ience here in the two systems, but in fact, of course, there are a number of 
differences emerging here in different parts of the world. The French, for 
example, are keen on this type of system. 
I would like to ask whether the Committee feels that at some later 
stage it is likely to be in the position to make more positive recommenda- 
tions and expressed preferences for these systems at very high-containment 
levels . 
DR. FREDRICKSON: Dr. Barkley. 
DR. BARKLEY: That is a very excellent suggestion. In some cases the 
desirability of the suit system has been based on a sense of convenience 
that those who have worked with those systems in the past probably do not 
share. I think the value of the suit system is really when one is dealing 
with developing systems that are difficult to think through in advance, 
where you have a lot of equipment and a lot of techniques when you are 
attempting to standardize a particular research approach. I think it would 
be very difficult to try to give guidance on its suitability for recombinant 
DNA research, but l think what could be done is to identify those options 
that were considered by those who have used the systems in the past. But 
I think in those areas that have used them in the past, one would find that a 
suit area would be on the order of maybe one percent of a total containment 
space. I think that gives you some indication of the true suitability for 
any type of research objective. But I think we could translate the use of 
the considerations in using suit areas for other human pathogenic work as at 
least some assistance in making decisions on whether one should go that route 
rather than the route of glove boxes. 
DR. FREDRICKSON: Dr. Sinsheimer. 
DR. SINSHEIMER: I would like to ask a question relative to the matter 
you were talking about where you were discussing the interchangeability, as 
it were, of physical and biological containment for certain purposes. It 
seems to me that can't wholly be addressed solely from the point of view of 
an individual worker or an individual laboratory, and that the hazard, if 
there be a hazard, is clearly also dependent, for example, on the number of 
workers and the number of laboratories. A move, let us say, from P3 to P2 
greatly increases the number of places at which that kind of work can go 
on. And it seems to me that needs to be considered as well. If you don't 
believe there is a hazard you are probably all in favor of that. If you do, 
then you would want to take that into consideration. 
Furthermore, it seems to me that obviously the effectiveness of any of 
these procedures depends somewhat on the attitude of the workers involved 
toward the procedures, in that since work in a P3 laboratory, for example, 
conveys a physical sense that you are doing something to take a precaution, 
it must create an impression, therefore, in the workers that maybe there 
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