APPENDIX E 
of the guidelines for appropriate revision. 
Pub I i cat i on ; The guidelines recommend that publications describing work 
on recombinant DNA include a description of the containment procedures used. 
Experiments to be Deferred ; The first class of experiments described in 
the guidel ines are those which are not to be carried out at the present time. 
While it may be argued that a combination of P4 physical containment and a 
high level of biological containment could essentially contain these recom- 
binants, the magnitude of the possible dangers, were containment to fail, 
dictates that these experiments be deferred. This class of experiments 
includes the following. 
(1) Any experiments in which a portion of the recombinant DNA derives 
from pathogenic organisms listed under classes 3, 4 and 5 of the document 
entitled Classification of Etiologic Agents on the basis of Hazard, as 
published by the Center for Disease Control, (CDC) United States Public 
Health Service or from oncogenic viruses classified by the National Cancer 
Institute as moderate risk. The CDC document categorizes naturally occurring 
organisms and viruses known to be pathogenic to man and agr icu I tura II y important 
species on a scale of increasing hazard, going from 1 to 5. Class 5 agents are 
excluded from the U. S. by law. Class 4 includes such agents as wild type small 
pox virus, wild type yellow fever virus. Herpesvirus simiae, and Lassa virus. 
Class 3 includes Brucella, arboviruses and agents causing encephalitis, 
psittacosis agents, rickettsiae and vesicular stomatitis virus. Class 2 includes 
agents which may produce diseases of varying degrees of severity if accidentally 
inoculated into laboratory workers, but which are considered normally containable 
Appendix E — 7 
