Attachment II - Page 35 
Federal Register / Vol. 49, No. 252 / Monday, December 31, 1984 / Notices 50889 
techniques used to produce it. (For 
similar reasons, EPA relied on process- 
based distinctions for many 
conventional chemical substances when 
the TSCA Inventory was compiled. See 
Refs. 33 and 34. Inventory listing issues 
are discussed in Unit III.D.4.) 
The Agency requests comments on its 
proposed mechanism for defining new 
microorganisms, and welcomes 
suggestions on other possible ways to 
demonstrate that a product is the 
equivalent of a naturally occurring 
substance. 
c. Discussion of specific processes. 
The following paragraphs discuss EPA’s 
proposed approach for distinguishing 
between “new" and “naturally 
occurring” microbes. The Agency 
requests comments on this approach. 
Comments should address: 
(1) The appropriateness of defining as 
"new” microorganisms produced 
through each of the techniques listed 
below. 
(2) Whether the underlying concepts 
of gene pool and degree of human 
intervention support the categorizations. 
(3) The potential for risk from 
microbial products developed through 
each of these techniques. 
(4) The practical considerations 
associated with a decision on each of 
the processes listed (eg., whether any 
are now in commercial production, 
whether the technique is definable In 
meaningful and unambiguous terms, 
etc.). 
(5) The definitions of the techniques in 
the glossary, including the extent to 
which they are clear and unambiguous. 
(6) Other techniques now being used 
or under development that should be 
addressed. 
(7) Possible ways of defining genetic 
boundaries among microorganisms. 
(8) Possible ways of differentiating 
degrees of human intervention. 
i. Chemical synthesis of nucleic acids. 
Chemical synthesis techniques are 
directed at iq vitro synthesis of nucleic 
acids from simpler molecules, not 
mediated by living organisms (Ref. 12). 
The chemical synthesis of a substance 
not listed on the TSCA Inventory 
creates a new chemical substance 
subject to PMN, regardless of whether 
an identical substance is naturally 
occurring. As a result, EPA believes that 
synthesized nucleic acids and microbes 
containing synthesized nucleic acids 
should be subject to PMN requirements, 
if they are produced for TSCA 
commercial purposes. 
U. Microbial products ofrDNA, rRNA, 
and cell fusion, that is, techniques that 
allow combinations in microorganisms 
of genetic material from organisms that 
do not exchange in nature. EPA believes 
that microorganisms which were 
produced by rDNA, rRNA and cell 
fusion techniques should be considered 
subject to PMN. The Agency recognizes 
that these techniques can be used to 
combine nucleic acids from organisms 
that exchange genetic material in nature, 
and therefore can be used to create 
organisms that theoretically “could" 
occur in nature, or that could be 
produced by random mutagenic events. 
Nevertheless, because these techniques 
involve direct human intervention at the 
cellular or subcellular level and allow 
genetic materials to be combined in 
organisms that do not naturally 
exchange genetic material, and given the 
practicality of a process-based 
distinction, EPA believes that the 
resulting organisms should be 
considered “new.” RDNA, rRNA and 
cell fusion techniques are defined, for 
the purposes of PMN requirements, in 
the glossary. 
These techniques may also be used to 
produce deletions, Le. losses of DNA 
sequences. Deletions generally lead to 
loss or modification of a function (e.g., 
loss of the frost-promoting activity of 
“ice-minus" bacteria). While deletions 
do not involve the mixing of gene pools 
and generally result in less hardy 
organisms, there can be circumstances 
where the loss of function may be 
significant (e.g. deletion may result in 
expression of otherwise repressed 
genes). Therefore, the Agency believes 
that deletions obtained with these 
techniques should be subject to PMN 
requirements. The Agency requests 
comments on this issue. 
EPA believes these same arguments 
apply to microorganisms produced 
through other techniques that can 
combine genetic material from 
organisms that do not exchange it in 
nature. Such techniques include cell 
microencapsulation and cell 
microinjection. Application of these 
techniques to microorganisms is in early 
stages of development. It is too' soon to 
know whether they will be successfully 
used to produce "new" microorganisms 
for commercial use. Products of these 
techniques will be subject to TSCA only 
if they are applied to microorganisms. 
EPA requests comment on this issue. 
Cell microinjection and cell 
microencapsulation are defined in the 
glossary of this notice. 
iii. Microbial products of other 
biotechnology techniques that promote 
exchange of genetic material. Other 
techniques are being used to transfer 
genetic material between 
microorganisms: they are usually used 
among organisms that are closely 
related. These techniques Include 
transformation, transduction. 
transfection, and techniques to promote 
plasmid transfer and conjugation. These 
techniques are defined in the glossary of 
this notice. 
The Agency has considered the 
factors which it uses to define "new” 
organisms; in this case, they do not 
clearly indicate how the techniques 
should be categorized. First, it is 
uncertain whether these techniques 
permit combinations that transcend 
natural boundaries. The Agency 
recognizes that these techniques can be 
used to transfer genetic material that 
could be exchanged in nature, and that 
some of them involve natural 
mechanisms for gene transfer. However, 
it has been shown that these techniques, 
together with artificial selection, can be 
used to develop microorganisms with 
particular traits that have not been 
found in nature (e.g., combinations of 
plasmids from various organisms in a 
pollutant-degrading microbe (Ref. 14)). 
Second, the fact that these techniques 
usually involve significant human 
intervention at the cellular or 
subcellular level, and the degree to 
which the transfer mechanisms are 
artificially promoted, suggest that the 
resulting organisms should be 
considered “new." 
Given the uncertain and perhaps 
competing considerations described 
above, the Agency is unsure as to 
whether the products of these 
techniques should be considered “new," 
and requests comment on the issues. 
hr. Microbial products of undirected 
mutagenesis. Certain techniques of 
biotechnology allow the development of 
microorganisms not by the combination 
of genetic material from different 
organisms, but by the artificial induction 
of mutations within organisms. These 
techniques include the longstanding use 
of undirected mutagenesis techniques to 
develop mutant microorganisms for the 
production of foods, pharmaceuticals, 
and chemicals. Undirected 
mutagenesis — the random action of 
chemical and physical mutagens — can 
be used to produce qualitatively or 
quantitatively different gene products, 
including deletion mutations which may 
cause loss of functions. 
The question of whether these 
techniques produce "new” 
microorganisms can be viewed from 
several perspectives. On the one hand, it 
can be argued that products of 
undirected mutagenesis are naturally 
occurring because the changes induced 
could be detected in natural populations 
as spontaneous mutations. In addition, 
the process takes place within the 
natural gene pool of the population, an' 1 
does not involve the introduction of 
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