10 . 
such experiments should be all together left undone. 
In summary then , we suggest that: 
1. PI & P2 be lumped together as one category ("no risk"); 
2. P3 be considered to be the most minimal level of physical 
containment ("minimal risk") for any experiments of 
"potential ly M hazardous or minimally hazardous nature. Since 
almost all experiments with recombinant DMA molecules can be 
considered at least potentially hazardous due to the as yet 
unforseeable consequences of these studies, almost all such 
experiments will require at least P3 containment. This would 
mean that P3 containment would span a much broader range (with 
a particular broadening to cover experiments, previously 
considered to be placed in the P2 level category in the 'Woods 
Hole Guidelines'). In addition, we cannot strongly enough 
emphasize that the 'loophole' presented in the 2nd paragraph 
coverning P3 containment in the guidelines be eliminated. 
And, 
3. P4 containment be the next and most stringent level of physical 
containment ("moderate-high risk"). Because of our lack of faith 
in the ' EK* biological levels of containment we point out here 
that many experiments previously suggested for P2 or P3 
restrictions along with some or another 'EK' restriction would 
prudently be carried out under P4-level containment. P4 may 
represent an inconvenience to those wishing to carry out this 
work. But, safety will have to take priority in the face of 
unknown risks, potential hazardous consequences of large 
magnitude, and the current poor choice of the biological system. 
[ 361 ] 
