The Honorable Patricia Roberts Harris 
December 30, 1979 
Page Three 
3. The NIh justification makes use of a scheme for assessing 
recombinant DNA risks developed by Dr. Sydney Brenner of the 
Laboratory of Molecular Biology in Cambridge, England* The scheme 
is being used by the British authorities to assess recombinant 
DHA projects. The description of the Brenner scheme (p.69237) 
suggests to the uninformed that this approach to risk assess- 
ment and the values embedded in it are in harmony with the 
arguments and values used to justify the "E.coli K-12/P1" 
proposal. In fact, there are important differences between the 
two approaches which lead to very different conclusions regarding 
both' containment precautions and general policy. Specifically: 
i) The Brenner scheme is being used within a regulatory 
system which covers all recombinant DNA activities in the public 
and the private sectors. Work is screened by a broadly con- 
stituted committee (the Genetic Manipulation Advisory Group) 
appointed by the Secretary for Education and Science. The com- 
mittee advises the Health and Safety Commission, which is responsible 
for promulgating and implementing regulations. Important elements 
of the British system are: 
a) Central registry and screening of recombinant DNA 
activities . 
b) Central collection of health data for individuals 
working in recombinant DNA facilities. 
c) Strong representation of the interests of employees 
at every level of the policy-making process. 
Elements b) and c) have no counterparts in the current system of 
controls in this country and element a) would be eliminated if 
the "E.coli K-12/P1" proposal is accepted. 
ii) According to the Brenner scheme, recombinant DNA hazards 
are assessed on a scale of 0 (no harmful outcome) to 1 (harmful 
outcome probable) . Work assessed at the lowest end of the scale is 
carried out under category I (comparable to PI) conditions. Work 
assessed at the hignest end of the scale is carried out under cate- 
gory IV (comparable to P4) conditions. The hazard of a particular 
process is determined according to the estimated values of three 
factors--f, the estimated fraction of DNA sequences capable of 
producing an outcome, h, the probability of expression, and a, 
the probability of access of a gene product, or the sequence itself, 
to an appropriate target--and the estimated probability of a harm- 
ful outcome which they jointly imply. It should be noted that: 
* This paper is in section 11 of the "Background Documents on 
E.coli K-12/P1 Recommendation," available from the NIH Office of 
Recombinant DNA Activities. 
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