Exemption Under the Federal Insecticide, Fungicide, and Rodenticide Act for Certain Plant-Incorporated Protectants Derived From Plant Viral Coat Protein Gene(s) (PVCP-PIPs); Supplemental Proposal, 19590-19640 [E7-7297]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 72, Number 74 (Wednesday, April 18, 2007)]
[Proposed Rules]
[Pages 19590-19640]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-7297]



[[Page 19589]]

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Part II





Environmental Protection Agency





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40 CFR Part 174



 Exemption Under the Federal Insecticide, Fungicide, and Rodenticide 
Act for Certain Plant-Incorporated Protectants Derived From Plant Viral 
Coat Protein (PVCP-PIPs) Gene(s); Supplemental Proposal; Proposed Rules

Federal Register / Vol. 72, No. 74 / Wednesday, April 18, 2007 / 
Proposed Rules

[[Page 19590]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 174

[EPA-HQ-OPP-2006-0642; FRL-8100-7]
RIN 2070-AD49


Exemption Under the Federal Insecticide, Fungicide, and 
Rodenticide Act for Certain Plant-Incorporated Protectants Derived From 
Plant Viral Coat Protein Gene(s) (PVCP-PIPs); Supplemental Proposal

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing to exempt from Federal Insecticide, 
Fungicide, and Rodenticide Act (FIFRA) requirements plant-incorporated 
protectants derived from plant viral coat protein genes (PVCP-PIPs) 
when the PVCP-PIP meets specified criteria. EPA is proposing this 
exemption because the Agency believes that the PVCP-PIPs covered by 
this exemption would be of a character which is unnecessary to be 
subject to FIFRA in order to carry out the purposes of the Act.

DATES: Comments must be received on or before July 17, 2007.

ADDRESSES: Submit your comments, identified by docket identification 
(ID) number EPA-HQ-OPP-2006-0642, by one of the following methods:
     Federal eRulemaking Portal: https://www.regulations.gov/. 
Follow the on-line instructions for submitting comments.
     Mail: Office of Pesticide Programs (OPP) Regulatory Public 
Docket (7502P), Environmental Protection Agency, 1200 Pennsylvania 
Ave., NW., Washington, DC 20460-0001.
     Delivery: OPP Regulatory Public Docket (7502P), 
Environmental Protection Agency, Rm. S-4400, One Potomac Yard (South 
Building), 2777 S. Crystal Drive, Arlington, VA. Deliveries are only 
accepted during the Docket's normal hours of operation (8:30 a.m. to 4 
p.m., Monday through Friday, excluding legal holidays). Special 
arrangements should be made for deliveries of boxed information. The 
Docket telephone number is (703) 305-5805.
    Instructions: Direct your comments to docket ID number EPA-HQ-OPP-
2006-0642. EPA's policy is that all comments received will be included 
in the docket without change and may be made available on-line at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through regulations.gov or e-
mail. The Federal regulations.gov website is an ``anonymous access'' 
system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through 
regulations.gov, your e-mail address will be automatically captured and 
included as part of the comment that is placed in the docket and made 
available on the Internet. If you submit an electronic comment, EPA 
recommends that you include your name and other contact information in 
the body of your comment and with any disk or CD-ROM you submit. If EPA 
cannot read your comment due to technical difficulties and cannot 
contact you for clarification, EPA may not be able to consider your 
comment. Electronic files should avoid the use of special characters, 
any form of encryption, and be free of any defects or viruses.
    Docket: All documents in the docket are listed in the docket index. 
Although listed in the index, some information is not publicly 
available, e.g., CBI or other information whose disclosure is 
restricted by statute. Certain other material, such as copyrighted 
material, is not placed on the Internet and will be publicly available 
only in hard copy form. Publicly available docket materials are 
available either in the electronic docket at https://
www.regulations.gov, or, if only available in hard copy, at the OPP 
Regulatory Public Docket in Rm. S-4400, One Potomac Yard (South 
Building), 2777 S. Crystal Drive, Arlington, VA. The hours of operation 
of this Docket Facility are from 8:30 a.m. to 4 p.m., Monday through 
Friday, excluding legal holidays. The Docket telephone number is (703) 
305-5805.

FOR FURTHER INFORMATION CONTACT: Melissa Kramer, Hazard Assessment 
Coordination and Policy Division (7202M), Office of Science 
Coordination and Policy, 1200 Pennsylvania Ave. NW, Washington, DC 
20460-0001; telephone number: (202) 564-8497; fax number: (202) 564-
8502; e-mail address: kramer.melissa@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Notice Apply to Me?

    You may be potentially affected by this action if you are a person 
or company involved with agricultural biotechnology that may develop 
and market plant-incorporated protectants. Potentially affected 
entities may include, but are not limited to:
     Pesticide and Other Agricultural Chemical Manufacturing 
(NAICS code 32532), e.g., establishments primarily engaged in the 
formulation and preparation of agricultural and household pest control 
chemicals;
     Crop Production (NAICS code 111), e.g., establishments 
primarily engaged in growing crops, plants, vines, or trees and their 
seeds;
     Colleges, Universities, and Professional Schools (NAICS 
code 611310), e.g., establishments of higher learning which are engaged 
in development and marketing of virus-resistant plants;
     Research and Development in the Physical, Engineering, and 
Life Sciences (NAICS code 54171), e.g., establishment primarily engaged 
in conducting research in the physical, engineering, or life sciences, 
such as agriculture and biotechnology.
    This listing is not intended to be exhaustive, but rather provides 
a guide for readers regarding entities likely to be affected by this 
action. Other types of entities not listed in this unit could also be 
affected. The North American Industrial Classification System (NAICS) 
codes have been provided to assist you and others in determining 
whether this action might apply to certain entities. To determine 
whether you or your business may be affected by this action, you should 
carefully examine the applicability provisions in 40 CFR part 174. If 
you have any questions regarding the applicability of this action to a 
particular entity, consult the person listed under FOR FURTHER 
INFORMATION CONTACT.

B. What Should I Consider as I Prepare My Comments for EPA?

    1. Docket. EPA has established a docket for this action under 
docket identification (ID) number EPA-HQ-OPP-2006-0642. Publicly 
available docket materials are available either in the electronic 
docket at https://www.regulations.gov, or, if only available in hard 
copy, at the Office of Pesticide Programs (OPP) Regulatory Public 
Docket in Rm. S-4400, One Potomac Yard (South Building), 2777 S. 
Crystal Drive Arlington, VA. The hours of operation of this Docket 
Facility are from 8:30 a.m. to 4 p.m., Monday through Friday, excluding 
legal holidays. The Docket telephone number is (703) 305-5805.

[[Page 19591]]

    2. Tips for preparing your comments. When submitting comments, 
remember to:
    i. Identify the document by docket ID number and other identifying 
information (subject heading, Federal Register date, and page number).
    ii. Follow directions. The Agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
    iii. Explain why you agree or disagree; suggest alternatives and 
substitute language for your requested changes.
    iv. Describe any assumptions and provide any technical information 
and/or data that you used.
    v. If you estimate potential costs or burdens, explain how you 
arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
    vi. Provide specific examples to illustrate your concerns and 
suggest alternatives.
    vii. Explain your views as clearly as possible, avoiding the use of 
profanity or personal threats.
    viii. Make sure to submit your comments by the comment period 
deadline identified.

II. Background

A. What Action is the Agency Proposing?

    EPA is proposing an exemption from FIFRA for certain plant virus 
coat protein plant-incorporated protectants or ``PVCP-PIPs.'' EPA is 
proposing to define a PVCP-PIP as ``a plant-incorporated protectant 
derived from one or more genes that encode a coat protein of a virus 
that naturally infects plants. This includes plant-incorporated 
protectants derived from one or more plant viral coat protein genes 
that produce only RNA and no virus-related protein.'' PVCP-PIPs 
introduced into plants with the intention of preventing or mitigating 
viral disease meet the FIFRA section 2(u) definition of ``pesticide'' 
because they are introduced into plants with the intention of 
``preventing, destroying, repelling, or mitigating any pest...'' (7 
U.S.C. 136(u)) and plant viruses meet the FIFRA section 2 definition of 
``pest'' (7 U.S.C. 136(t)). EPA is proposing this exemption because the 
Agency believes that the PVCP-PIPs covered by this exemption would be 
of a character which is unnecessary to be subject to FIFRA in order to 
carry out the purposes of the Act.
    A PIP can be exempt from the requirements of FIFRA, other than the 
adverse effects reporting requirements of 40 CFR 174.71, if it meets 
all three of the requirements listed in 40 CFR 174.21. Section 
174.21(a) requires that the PIP meet the criteria listed in at least 
one of the sections in Sec. Sec.  174.25 through 174.50. Section 
174.21(b) requires that when the PIP is intended to be produced and 
used in a crop used as food, the residues of the PIP are either 
exempted from the requirement of a tolerance under FFDCA or no 
tolerance would otherwise be required for the PIP. Section 174.21(c) 
requires that an exempt PIP must contain only those inert ingredient(s) 
included on the list codified at Sec. Sec.  174.485 through 174.490. 
(Reference to Sec. Sec.  174.485 through 174.490 in Sec.  174.21(c) is 
proposed to be changed to refer to Sec. Sec.  174.485 through 174.486 
in today's Proposed Rule.) See Unit II.F. for further discussion of 
these Sec.  174.21 criteria.
    The rule proposed in today's Federal Register would establish 40 
CFR 174.27, which would contain three criteria that, when met, would 
allow PVCP-PIPs to meet the general requirement for exemption for all 
PIPs listed at 40 CFR 174.21(a). Today's Federal Register also proposes 
to add several substances known to be used as inert ingredients in PIPs 
to 40 CFR part 174 subpart X, thereby potentially expanding the PVCP-
PIPs that could meet the conditions of Sec.  174.21(c). A companion 
document published elsewhere in today's Federal Register also proposes 
a tolerance exemption for certain PVCP-PIP residues, thereby 
potentially expanding the PVCP-PIPs that could meet the conditions of 
Sec.  174.21(b).
    The three criteria that EPA is proposing to insert at 40 CFR 174.27 
are intended to address three issues that may be associated with a 
PVCP-PIP. These issues are:
     The potential for increased weediness or invasiveness of 
the crop plant containing the PVCP-PIP or any wild or weedy relatives 
that could acquire the PVCP-PIP through gene flow thereby causing 
negative effects on either the agro-ecosystem or natural environments. 
This issue is addressed in proposed Sec.  174.27(a).
     The potential that viruses with novel properties could 
develop through novel viral interactions. This issue is addressed in 
proposed Sec.  174.27(b).
     The potential for human or nontarget organism exposure to 
proteins that have not previously existed in nature and thus should be 
examined to determine whether they have potentially toxic or allergenic 
properties. This issue is addressed in proposed Sec.  174.27(c).
    In order to satisfy 40 CFR 174.21(a), a PVCP-PIP would have to 
satisfy proposed Sec.  174.27(a), (b), and (c). The requirements at 
Sec.  174.27(d) would also have to be met to qualify for exemption. 
Proposed Sec.  174.27(a), (b), and (c) each can be met in one of two 
ways: a product developer may self-determine that paragraph (1) of the 
criterion applies (i.e., Sec.  174.27(a)(1), (b)(1), or (c)(1)) or the 
Agency may determine that paragraph (2) of the criterion applies (i.e., 
Sec.  174.27(a)(2), (b)(2), or (c)(2), respectively). Paragraph (1) of 
each proposed criterion (i.e., Sec.  174.27(a)(1), (b)(1), and (c)(1)) 
describes an objective, well-defined characteristic. Therefore, the 
developer may determine whether the PVCP-PIP meets the requirement. 
Paragraph (2) of each proposed criterion (i.e., Sec.  174.27(a)(2), 
(b)(2), and (c)(2)) is conditioned on an Agency determination because 
it may involve analysis of several types of information. Each criterion 
may be satisfied either by self determination under paragraph (1) or 
Agency determination under paragraph (2) irrespective of how the other 
two criteria are satisfied; there is no requirement that all three 
criteria must be satisfied under either paragraph (1) or paragraph (2) 
in order to qualify for the exemption.

B. What is the Agency's Authority for Taking this Action?

    This rule is promulgated under the authority of FIFRA sections 
3(a), 25(a), and 25(b) (7 U.S.C. 136a(a), 136w(a), and 136w(b)).
    FIFRA section 3(a) states that, except as provided by the Act, no 
person may distribute or sell in the United States any pesticide that 
is not registered under the Act (7 U.S.C. 136(a)). FIFRA section 2(u) 
defines ``pesticide'' as: ``(1) any substance or mixture of substances 
intended for preventing, destroying, repelling, or mitigating any pest, 
(2) any substance or mixture of substances intended for use as a plant 
regulator, defoliant, or desiccant, and (3) any nitrogen 
stabilizer...'' (7 U.S.C. 136(u)). Under FIFRA section 2(t), the term 
``pest'' includes ``(1) any insect, rodent, nematode, fungus, weed, or 
(2) any other form of terrestrial or aquatic plant or animal life or 
virus, bacteria, or other microorganism... which the Administrator 
declares to be a pest...'' subject to certain exceptions (7 U.S.C. 
136(t)).
    Before EPA may register a pesticide under FIFRA, the applicant must 
show that the pesticide ``when used in accordance with widespread and 
commonly recognized practice... will not generally cause unreasonable 
adversese effects on the environment'' (7 U.S.C. 136a(c)(5)(D)). The 
term ``environment'' includes ``water, air, land, and all plants and 
man and other

[[Page 19592]]

animals living therein, and the interrelationships which exist among 
these'' (7 U.S.C. 136(j)). FIFRA section 2(bb) defines the term 
``unreasonable adverse effects on the environment'' to mean: ``(1) any 
unreasonable risk to man or the environment, taking into account the 
economic, social, and environmental costs and benefits of the use of 
any pesticide, or (2) a human dietary risk from residues that result 
from a use of a pesticide in or on any food inconsistent with the 
standard under section 408 of the Federal Food, Drug, and Cosmetic 
Act'' (7 U.S.C. 136(bb)).
    Although FIFRA requires the registration of most pesticides, it 
also authorizes the regulation of unregistered pesticides. FIFRA 
section 3(a) provides that, to the extent necessary to prevent 
unreasonable adverse effects on the environment, the Administrator may 
limit the distribution, sale, or use of any pesticide that is not 
registered under section 3 of FIFRA, subject to an experimental use 
permit under section 5 of FIFRA, or subject to an emergency exemption 
under section 18 of FIFRA. Pesticides that are ``not registered'' 
include pesticides that are exempt from FIFRA requirements under 
section 25(b).
    An unregistered pesticide may be distributed or sold if it is 
exempted by regulation under FIFRA section 25(b). Under FIFRA section 
25(b)(2), the Agency can exempt pesticides from some or all of the 
requirements of FIFRA when the Agency determines that the pesticide is 
``of a character which is unnecessary to be subject to [FIFRA] in order 
to carry out the purposes of this Act'' (7 U.S.C. 136w(b)(2)). EPA 
interprets section 25(b)(2) to authorize the Agency to exempt a 
pesticide or category of pesticides that EPA determines (1) poses a low 
probability of risk to the environment and (2) is not likely to cause 
unreasonable adverse effects to the environment even in the absence of 
regulatory oversight under FIFRA. This standard differs from the 
standard for registration which considers only whether the pesticide 
``when used in accordance with widespread and commonly recognized 
practice... will not generally cause unreasonable adverse effects on 
the environment'' (7 U.S.C. 136a(c)(5)(D)).
    In evaluating the first condition that must be met for the Agency 
to exempt a pesticide, i.e., whether use of the pesticide poses a low 
probability of risk to the environment, EPA considers the extent of the 
potential risks caused by use of the pesticide to the environment, 
including humans and other animals, plants, water, air and land. 
Potential risks to humans include dietary risks as well as non-dietary 
risks such as those resulting from occupational or residential exposure 
to the pesticide. EPA uses the FFDCA section 408 standard in evaluating 
dietary risks as discussed in Unit II.C. of this preamble. EPA will not 
exempt pesticides unless they pose a low probability of risk to the 
environment.
    In evaluating the second condition that must be met for the Agency 
to exempt a pesticide, i.e., whether the use of the pesticide is 
unlikely to cause unreasonable adverse effects on the environment even 
in the absence of regulatory oversight under FIFRA, EPA balances all 
the potential risks to human health, including dietary risks (see Unit 
II.C. of this preamble for discussion of the FFDCA standard), and risks 
to the remainder of the environment from use of the pesticide against 
the potential benefits associated with its use. In balancing risks and 
benefits, EPA considers the economic, social, and environmental costs 
and benefits of the use of the pesticide. If the pesticide poses a low 
probability of risk to the environment and is not likely to cause 
unreasonable adverse effects to the environment even in the absence of 
regulatory oversight under FIFRA, EPA may exempt the pesticide from 
regulation under FIFRA.

C. What is the Relationship of FIFRA Exemptions to the FFDCA Section 
408 Standard?

    Under FFDCA section 408(a), a pesticide chemical residue in or on a 
food (hereafter simply ``in food'') is not considered safe unless EPA 
has issued a tolerance for the residue and the residue is within the 
established tolerance limit or EPA has issued an exemption from the 
requirement of a tolerance for the residue (21 U.S.C. 346a(a)(1)). 
FFDCA section 408 authorizes EPA to determine a residue is safe and 
therefore exempt from the requirement of a tolerance if the 
Administrator ``has determined that there is a reasonable certainty 
that no harm will result from aggregate exposure to the pesticide 
chemical residue, including all anticipated dietary exposures and all 
other exposures for which there is reliable information'' (21 U.S.C. 
346a(c)(2)(A)(ii)). Section 408 of the FFDCA also directs EPA to 
specifically consider harm that may result to infants and children as a 
result of pesticide chemical residues. For additional discussion of 
this standard, see the Exemption from the Requirement of a Tolerance 
under the Federal Food, Drug, and Cosmetic Act for Residues of Plant 
Virus Coat Proteins that are Part of a Plant-Incorporated Protectant 
published concurrently in today's Federal Register.
    EPA uses the FFDCA section 408 safety standard in evaluating 
whether a pesticide used in food meets the FIFRA section 25(b)(2) 
exemption standard with respect to human dietary risk. A pesticide in 
food poses a low probability of human dietary risk if it meets the 
FFDCA section 408 standard for an exemption from the requirement of a 
tolerance. Such a pesticide also is not likely to cause unreasonable 
adverse effects to the environment, with respect to human dietary risk 
only, if the dietary risks resulting from use of that pesticide are 
consistent with the FFDCA section 408 exemption standard, and the 
potential benefits of use outweigh any dietary risk even in the absence 
of regulatory oversight.
    FIFRA, however, does not provide for exemption of a pesticide in 
food based solely upon human dietary risk and consistency with the 
FFDCA section 408 exemption standard; an exemption from the 
requirements of FFDCA does not exempt a product from regulation under 
FIFRA. For an exemption under FIFRA, EPA must also evaluate non-dietary 
risks to humans and the remainder of the environment from the pesticide 
and determine both that the pesticide poses only a low probability of 
non-dietary risks and that use of the pesticide is not likely to cause 
any unreasonable adverse effects to the environment from such 
nondietary risks in the absence of regulation.

D. What is the Role of Other Federal Agencies?

    EPA is the Federal agency responsible for the regulation of 
pesticides. Under the Coordinated Framework for Regulation of 
Biotechnology (51 FR 23302, June 26, 1986), EPA works closely with the 
U.S. Department of Agriculture (USDA), which has responsibilities under 
the Plant Protection Act (PPA), and the U.S. Food and Drug 
Administration (FDA), which has responsibilities under FFDCA. EPA, 
USDA, and FDA consult and exchange information when such consultation 
is helpful in resolving safety questions. The three agencies also 
strive for consistency between programs following one of the basic 
tenets of the Coordinated Framework, i.e., that the agencies composing 
the Framework adopt consistent approaches to the extent permitted by 
the respective statutory authorities. A consistent approach between 
agencies is easier for the regulated community to understand, and it 
likely conserves resources

[[Page 19593]]

because data developed for one agency may meet at least some of the 
requirements posed by another agency for the same or similar products.
    1. USDA. USDA has the responsibility of preventing the introduction 
and dissemination of plant pests under the PPA. Before a genetically 
engineered plant that is subject to the PPA may be introduced into the 
environment, approval must be obtained from the USDA/Animal Plant 
Health Inspection Service (APHIS) unless such a plant has been reviewed 
and granted Nonregulated Status. The USDA regulations use genetic 
engineering and potential plant pest risk as criteria for determining 
the scope of its regulations (62 FR 23945, May 2, 1997). Any 
genetically engineered plant that contains genetic material from a 
plant pest is subject to the regulations. Thus, all plants containing 
PVCP-PIPs are subject to USDA/APHIS requirements under the PPA.
    EPA therefore recognizes that there is a potential for duplicative 
oversight with respect to certain issues that may arise in decisions 
about PVCP-PIPs that require any review by EPA. For example, in its 
reviews of Petitions for Determination of Nonregulated Status under 
regulations at 7 CFR part 340, the potential for weediness, for 
displacement of native species, and potential consequences of gene 
transfer are evaluated by USDA/APHIS. EPA and USDA/APHIS will continue 
to consult and collaborate on reviews of PVCP-PIPs. EPA and USDA/APHIS 
will work together to avoid potential duplication and inconsistencies 
and to coordinate their analyses in accordance with their respective 
expertise and jurisdiction.
    2. FDA. FDA is the primary U.S. agency responsible for ensuring the 
safety of commercial food and food additives. FDA's authority under 
FFDCA extends to any nonpesticidal substance that may be introduced 
into a new plant variety and that is expected to become a component of 
food. Pursuant to sections 201 and 408 of FFDCA and the creation of 
EPA, pesticide chemical residues are subject to EPA's regulatory 
authority under FFDCA.

E. What is a PVCP-PIP?

    EPA is proposing to define a PVCP-PIP as ``a plant-incorporated 
protectant derived from one or more genes that encode a coat protein of 
a virus that naturally infects plants. This includes plant-incorporated 
protectants derived from one or more plant viral coat protein genes 
that produce only RNA and no virus-related protein.''
    Coat proteins are those substances that viruses produce to 
encapsulate and protect the viral nucleic acid and to perform other 
important tasks for the virus, e.g., assistance in viral replication, 
movement within the plant, and transmission of the virus from plant to 
plant by insects (Ref. 1). In many cases, when the genetic material 
encoding a plant virus coat protein is engineered into a plant's 
genome, the plant displays resistance to infection by that virus as 
well as other viruses having similar coat protein sequences (Ref. 2).
    Current scientific information suggests that prevention or 
mitigation of disease by PVCP-PIPs may occur by two different 
mechanisms. For some PVCP-PIPs, resistance is believed to be protein-
mediated because efficacy is correlated with the concentration of coat 
protein produced by the transgene (Ref. 3). In protein-mediated 
resistance, the coat protein is thought to impede the infection cycle 
by interfering with the disassembly of infecting viruses (Ref. 4).
    In transgenic plants, a second mechanism of resistance, post-
transcriptional gene silencing (PTGS) may be activated. In PTGS, 
prevention or mitigation of viral disease is not correlated with the 
level of coat protein expression. Indeed, virus resistance can occur 
even when a coat protein gene expresses untranslatable RNA sequences 
and no coat protein is detected (Ref. 4). PTGS is a defense mechanism 
in plants against foreign RNA (e.g., viruses) in which sequence-
specific RNA degradation is initiated by the plant in response to the 
foreign RNA itself. Evidence suggests that PTGS is initiated once there 
is a threshold accumulation of double-stranded (ds) RNA in the cell 
cytoplasm (Ref. 5). Over 90% of plant viruses have single-stranded RNA 
genomes, but viral replication transiently produces dsRNA in quantities 
sufficient to trigger PTGS (Ref. 6). PTGS is also known to occur with 
transgenes that are transcribed at a low level but that likely produce 
dsRNA (Ref. 7). Once the plant recognizes the dsRNA, it is thought to 
be cleaved by a dsRNA-specific nuclease to produce small 21- to 25-
nucleotide short interfering RNA sequences (siRNAs; Ref. 8). The siRNAs 
are thought to serve as guides for the cleavage of single-stranded RNA 
with a sequence similar to the dsRNAs (Ref. 9). Thus once PTGS is 
initiated, it targets all RNA with high sequence similarity to the 
sequence that initiated the process, regardless of whether it was 
transcribed from the transgene, an endogenous gene, or viral RNA.
    A plant virus coat protein transgene that confers virus resistance 
through either a protein- or RNA-mediated mechanism would fall within 
EPA's proposed definition of a PVCP-PIP. The substances involved in 
either mechanism of resistance would meet the FIFRA definition of a 
pesticide because the transgene and any material expressed from the 
transgene are introduced into a plant for the purpose of preventing or 
mitigating viral disease (see Unit II.A.).
    The proposed definition of a PVCP-PIP contains the phrase 
``naturally infects plants.'' Including this phrase in the definition 
would specifically limit the proposed exemption by requiring that the 
virus coat protein gene sequence used in the PVCP-PIP be based 
exclusively on a plant virus sequence. This limitation is proposed in 
order to exclude from the definition any coat proteins of plant viruses 
that have been modified with sequences from animal or human viruses. 
EPA includes this concept in today's proposal in response to comment 
received from the public in earlier Federal Register documents 
pertaining to PVCP-PIPs.

F. What Conditions Must be Met for a PVCP-PIP to Qualify for a FIFRA 
Exemption?

    As noted above, a PIP is exempt from the requirements of FIFRA, 
other than the adverse effects reporting requirements of 40 CFR 174.71, 
if the PIP meets the requirements in 40 CFR 174.21(a), (b), and (c). 
Therefore, the following factors need to be considered to determine the 
FIFRA status of a PVCP-PIP. First, does the PVCP-PIP meet the 
requirement at 40 CFR 174.21(a)? Second, do the residues of the PVCP-
PIP meet the requirement at 40 CFR 174.21(b)? Third, do the inert 
ingredients that are part of the PVCP-PIP meet the requirement at 40 
CFR 174.21(c)?
    1. Does the PVCP-PIP meet the requirement at 40 CFR 174.21(a)? 
Section 174.21(a) requires that the PIP meet the criteria listed in at 
least one of the sections in Sec. Sec.  174.25 through 174.50. Today's 
action proposes to establish Sec.  174.27, which would contain criteria 
allowing certain PVCP-PIPs to meet the Sec.  174.21(a) requirement for 
exemption. These criteria identify those PVCP-PIPs that EPA has been 
able to determine meet the standard under FIFRA section 25(b)(2), i.e., 
that pose a low probability of risk to the environment and that are not 
likely to cause unreasonable adverse effects to the environment even in 
the absence of regulatory oversight under FIFRA. EPA is proposing 
criteria that address the

[[Page 19594]]

relevant potential risks associated with these products:
    i. The potential for increased weediness or invasiveness of the 
crop plant containing the PVCP-PIP or any wild or weedy relatives that 
could acquire the PVCP-PIP through gene flow thereby causing negative 
effects on either the agro-ecosystem or natural environments. This 
issue is addressed at Sec.  174.27(a) and is referred to as 
``weediness'' for the purposes of this document.
    ii. The potential for viruses with novel properties developing 
through novel viral interactions. This issue is addressed at Sec.  
174.27(b) and is referred to as ``viral interactions'' for the purposes 
of this document.
    iii. The potential for human or nontarget organism exposure to 
proteins that may not have previously existed in nature and thus should 
be examined to determine whether they have potentially toxic or 
allergenic properties. This issue is addressed at Sec.  174.27(c) and 
is referred to as ``protein production'' for the purposes of this 
document.
    Proposed Sec. Sec.  174.27(a), (b), and (c) are discussed in 
greater detail in Unit III of this Federal Register document. In 
addition, a graphical depiction of what this rule is proposing is 
available in the docket for this proposed rule.
    2. Do the residues of the PVCP-PIP meet the requirement at 40 CFR 
174.21(b)? Section 174.21(b) requires that in order to qualify for a 
FIFRA exemption, the residues of a PVCP-PIP that is intended to be 
produced and used in a crop used as food must either be exempted from 
the requirement of a tolerance under FFDCA or no tolerance would 
otherwise be required for the PVCP-PIP. Therefore, if a PVCP-PIP is 
used in a food plant (e.g., the PVCP-PIP is produced and used in a corn 
plant) or residues of the PVCP-PIP might reasonably be expected in food 
(e.g., the PVCP-PIP is produced and used in an ornamental plant but 
could move through gene flow to a sexually compatible food plant), the 
FFDCA section 408 requirements must be considered when determining 
whether the PVCP-PIP can be exempted under FIFRA. If a PVCP-PIP would 
not be used in and would not reasonably be expected in a crop used as 
food (e.g., the PVCP-PIP is produced and used in an ornamental plant 
with no sexually compatible relatives that are food plants), the FFDCA 
section 408 requirements do not need to be considered.
    EPA anticipates that in most cases the PVCP-PIP residues will 
consist of residues of nucleic acids, residues of inert ingredients, 
and residues of the plant virus coat protein portion of the PVCP-PIP 
(the ``PVC-protein''). Residues of nucleic acids are exempt from the 
requirement of a tolerance at 40 CFR 174.475. As of the time this 
proposed rule is being issued, residues of those inert ingredients that 
are exempt from the requirement of a tolerance are listed at 40 CFR 
part 180 and 40 CFR part 174 subpart W. In a companion piece appearing 
in today's Federal Register, EPA is proposing a tolerance exemption for 
residues of certain PVC-proteins that meet specified criteria. Due to 
different statutory requirements, the proposed FFDCA exemption criteria 
differ from the criteria proposed in this Federal Register for 40 CFR 
174.27 under FIFRA.
    3. Do the inert ingredients that are part of the PVCP-PIP meet the 
requirement at 40 CFR 174.21(c)? Section 174.21(c) requires that in 
order for a PIP to qualify for exemption any inert ingredient contained 
in the PIP must be codified at subpart X of 40 CFR part 174 - List of 
Approved Inert Ingredients. Subpart X lists the inert ingredients (i) 
that may be used in a plant-incorporated protectant listed in subpart B 
(Exemptions) of part 174 and (ii) whose residues are either exempted 
from the requirement of a tolerance under FFDCA or no tolerance would 
otherwise be required. EPA is proposing to add several substances known 
to be used commonly as inert ingredients in PIPs to 40 CFR part 174 
subpart X. These substances already have tolerance exemptions under 
FFDCA. EPA proposes in today's Federal Register that these substances, 
when used in exempt PIPs as inert ingredients under specified 
conditions, should also be exempt from FIFRA because they are of a 
character which is unnecessary to be subject to FIFRA in order to carry 
out the purposes of the Act.

G. What if a PVCP-PIP Does Not Qualify for Exemption?

    If EPA is unable to conclude that a PVCP-PIP meets the standard for 
exemption, an applicant may still apply to register the PVCP-PIP under 
section 3 of FIFRA. EPA may be able to conclude that the PVCP-PIP meets 
the standard for registration (i.e., when it is used in accordance with 
widespread and commonly recognized practice, it will not generally 
cause unreasonable adverse effects on the environment). EPA recognizes 
that the proposed exemption criteria may not identify all low risk 
PVCP-PIPs. A case-by-case review for registration would allow the 
Agency to evaluate factors not readily incorporated into clear, 
unambiguous exemption criteria. As part of registration, the Agency 
could also impose conditions of use as appropriate. As is EPA's general 
practice regarding registration of PIPs, the Agency will consult with 
USDA in evaluating PVCP-PIPs for registration.

H. What is the History of this Proposal?

    1. Scientific input. EPA sponsored or cosponsored with other 
Federal agencies, six conferences relevant to development of this 
proposed rule: on October 19-21, 1987, a meeting on ``Regulatory 
Considerations: Genetically Engineered Plants'' at Cornell University 
in Ithaca, New York; on September 8-9, 1988, a ``Transgenic Plant 
Conference'' in Annapolis, Maryland; on November 6-7, 1990, a 
conference on ``Pesticidal Transgenic Plants: Product Development, Risk 
Assessment, and Data Needs'' in Annapolis, Maryland; on April 18-19, 
1994, a ``Conference on Scientific Issues Related to Potential 
Allergenicity in Transgenic Food Crops'' in Annapolis, Maryland; on 
July 17-18, 1997, a ``Plant Pesticide Workshop'' in Washington, DC; and 
on December 10-12, 2001 a conference on ``Assessment of the Allergenic 
Potential of Genetically Modified Foods'' in Chapel Hill, North 
Carolina. EPA incorporated information from these conferences in 
development of this proposed rule as appropriate.
    EPA has requested the advice of two scientific advisory bodies at 
five meetings while developing its approach to plant-incorporated 
protectants. On December 18, 1992, EPA convened a FIFRA Scientific 
Advisory Panel (SAP) to review a draft policy on PIPs (then called 
plant-pesticides) and to respond to a series of related questions posed 
by the Agency dealing primarily with EPA's approach under FIFRA. On 
July 13, 1993, EPA requested the advice of a Subcommittee of the EPA 
Biotechnology Science Advisory Committee (BSAC) on a series of 
scientific questions dealing with EPA's approach to PIPs under FFDCA. 
On January 21, 1994, EPA asked for advice on the Agency's approach to 
PIPs under both statutes at a joint meeting of the SAP and the BSAC. To 
evaluate more recent scientific advances, EPA again brought these 
issues to a FIFRA SAP meeting on October 13-14, 2004. On December 6-8, 
2005, EPA convened a SAP meeting to address a series of scientific 
questions related to this proposal. EPA incorporated advice from all 
five meetings in development of this proposed rule as appropriate.
    2. Federal Register documents. The history of this proposal 
consists of the original proposed exemption from

[[Page 19595]]

FIFRA requirements that appeared in the November 23, 1994 Federal 
Register (59 FR 60519); the original proposed exemption from FFDCA 
tolerance requirements in the November 23, 1994 Federal Register (59 FR 
60545); and several supplemental documents appearing in the May 16, 
1997 Federal Register (59 FR 27149), the July 22, 1996 Federal Register 
(61 FR 37891), the April 23, 1999 Federal Register (64 FR 19958), and 
the July 19, 2001 Federal Register (66 FR 37772 and 37855).
    i. November 23, 1994. In a document that appeared in the November 
23, 1994 Federal Register (59 FR 60519) (FRL-4755-3), EPA proposed two 
alternatives under FIFRA section 25(b)(2) to exempt PVCP-PIPs from 
FIFRA requirements. Option 1 proposed to categorically exempt plant-
pesticides derived from coat proteins from plant viruses (now called 
PVCP-PIPs). Option 2 proposed a more limited exemption covering only 
those PVCP-PIPs that would have the least potential to confer selective 
advantage on free-living wild relatives of the plants that could 
acquire the PVCP-PIP through gene flow (discussed in detail in Unit 
III.C.3.).
    Elsewhere in the November 23, 1994, Federal Register (59 FR 60545) 
(FRL-4755-4), EPA proposed to exempt from the FFDCA requirement of a 
tolerance, residues of plant virus coat proteins produced and used in 
living plants as a plant-incorporated protectant (then called a plant-
pesticide). The proposed exemption from the requirement of a tolerance 
read, ``Residues of coat proteins from plant viruses, or segments of 
the coat proteins, produced in living plants as plant-pesticides are 
exempt from the requirement of a tolerance'' (59 FR 60547).
    ii. May 16, 1997. In August of 1996, Congress enacted the Food 
Quality Protection Act (FQPA), which amended FFDCA and FIFRA. On May 
16, 1997, EPA published a supplemental document in the Federal Register 
(62 FR 27149) (FRL-5716-6) to provide the public with an opportunity to 
comment on EPA's analysis of how certain FQPA amendments to FFDCA and 
FIFRA applied to the 1994 proposed exemption from the requirement of a 
tolerance for residues of viral coat proteins produced in plants as 
part of a PIP. (Today's Federal Register terms such entities ``PVC-
proteins.'')
    In the 1997 supplemental document, EPA explained how most of the 
substantive factors that the amended FFDCA requires EPA to consider in 
evaluating pesticide chemical residues had been considered in the 
Agency's 1994 proposed tolerance exemption. Even though the Agency may 
not have used the terminology specified in the FQPA, EPA did take into 
account most of the factors (e.g., toxicity and consumption patterns) 
in issuing its 1994 proposal to exempt residues of PVC-proteins, or 
residues of segments of such proteins, from FFDCA tolerance 
requirements. EPA therefore sought comment on the requirements imposed 
by FQPA that the Agency had not addressed in its 1994 proposal, 
specifically:
    a. EPA's conclusion that there are no substances outside of the 
food supply that may have a cumulative toxic effect with residues of 
PVC-proteins,
    b. EPA's conclusion that there are no substances outside of the 
food supply to which humans might be exposed through non-occupational 
routes of exposure that are related via a common mechanism of toxicity 
to residues of PVC-proteins,
    c. Any available information on PVC-proteins causing estrogenic 
effects,
    d. EPA's rationale, described in greater detail, for concluding 
that PIPs are likely to present a limited exposure of pesticidal 
substances to humans in which the predominant route of exposure will be 
dietary, and
    e. EPA's rationale, described in greater detail, for concluding 
that the Agency's analysis concerning the dietary safety of food 
containing PVC-proteins applies to infants and children as well as 
adults.
    Because of the 1996 FQPA, EPA's final determination under FIFRA for 
PVCP-PIPs in food plants could also be affected by comments on the 
companion document in today's Federal Register that proposes a 
tolerance exemption for certain PVCP-PIP residues.
    iii. July 22, 1996. On July 22, 1996, EPA issued a supplemental 
document (61 FR 37891) (FRL-5387-4) requesting comment on one aspect of 
its November 23, 1994 Federal Register document: how the concept of 
inert ingredient related to plant-incorporated protectants.
    iv. April 23, 1999. On April 23, 1999, EPA published a supplemental 
document in the Federal Register (64 FR 19958) (FRL-6077-6) soliciting 
comment on whether to change the name of pesticides produced and used 
in living plants.
    v. July 19, 2001. In July of 2001, EPA published a package of 
notices related to PIPs in the Federal Register, including a 
supplemental document (66 FR 37855) (FRL-6760-4) that provided the 
public with additional opportunity to comment on the FIFRA and FFDCA 
exemptions for PIPs that the Agency proposed in 1994 but had not yet 
finalized by 2001. EPA also requested comment on the information, 
analyses, and conclusions pertaining to these PIPs (including PVCP-
PIPs) contained in the NRC report entitled ``Genetically Modified Pest-
Protected Plants: Science and Regulation'' (Ref. 10). The public was 
given an opportunity to comment on a proposal to clarify the language 
of the original 1994 proposals EPA was considering in response to 
public comment received on the 1994 proposal. In addition, the Agency 
requested additional public comment on several scientific issues. Also 
in the July 19, 2001 Federal Register (66 FR 37772) (FRL-6057-7), EPA 
changed the name of these pesticides from ``plant-pesticides'' to 
``plant-incorporated protectants'' or ``PIPs.''
    The documents and reports of the meetings described above, 
including associated public comments, are available in the public 
dockets established for the associated rulemakings as described in Unit 
IX of this preamble.
    Today's proposed rule completely supersedes these previous 
proposals. EPA does not intend to respond to comments submitted on 
those proposals. Thus, individuals who believe that any comments 
submitted on any of the earlier proposals remain germane to today's 
proposal, should submit them (or relevant portions) again during this 
comment period.

III. Proposed Exemption Criteria under Sec.  174.27

A. Structure of the Proposed Exemption Criteria under Sec.  174.27

    In order to satisfy the general requirement for a FIFRA exemption 
listed at 40 CFR 174.21(a), EPA is proposing to add three criteria at 
40 CFR 174.27. As discussed in Unit II.F.1., the three criteria that 
EPA is proposing to adopt at 40 CFR 174.27 are intended to address 
three issues that are associated with potential risks of PVCP-PIPs.
    The PVCP-PIP would have to meet proposed Sec. Sec.  174.27(a), (b), 
and (c) to satisfy 40 CFR 174.21(a). Proposed Sec. Sec.  174.27(a), 
(b), and (c) each can be met in one of two ways: a product developer 
may self-determine that paragraph (1) of the criterion is met (i.e., 
Sec.  174.27(a)(1), (b)(1), or (c)(1)) or the Agency may determine that 
paragraph (2) of the criterion is met (i.e., Sec.  174.27(a)(2), 
(b)(2), or (c)(2), respectively). Paragraph (1) of each proposed 
criterion (i.e., Sec.  174.27(a)(1), (b)(1), and (c)(1)) describes an 
objective, well-defined characteristic. Therefore, the developer may 
determine whether the PVCP-PIP meets the requirement. Paragraph (2) of

[[Page 19596]]

each proposed criterion (i.e., Sec.  174.27(a)(2), (b)(2), and (c)(2)) 
is conditioned on an Agency determination because several types of 
information may need to be evaluated using a weight-of-evidence 
approach to determine whether the PVCP-PIP meets the requirement and is 
therefore of a nature warranting exemption.
    1. Exemption by self-determination. Each criterion may be satisfied 
under either paragraph (1) or paragraph (2) irrespective of how the 
other two criteria are satisfied; there is no requirement that all 
three criteria must be satisfied under either paragraph (1) or 
paragraph (2) in order for a PVCP-PIP to qualify for the exemption. 
However, if a PVCP-PIP satisfies all three criteria under paragraph (1) 
by developer self determination (i.e., it meets proposed Sec. Sec.  
174.27(a)(1), (b)(1), and (c)(1)) and it satisfies Sec. Sec.  174.21(b) 
and (c), EPA is proposing that the developer submit a notification to 
the Agency of that determination and certify that the PVCP-PIP 
qualifies for exemption under FIFRA, i.e., that the PVCP-PIP meets 
Sec. Sec.  174.21(a), (b), and (c). In addition, EPA is proposing that 
the developer maintain information adequate to support the 
determination. Such records must be made available for EPA inspection 
and copying or be otherwise submitted to the Agency for review upon 
request for the duration of time that the PVCP-PIP is sold or 
distributed. EPA is proposing that these records be kept so that EPA 
could review a particular exemption determination if needed at a future 
date.
    EPA is proposing to require that the notifications contain:
    i. The name of the crop (including genus and species) containing 
the PVCP-PIP.
    ii. The name of the virus from which the coat protein gene was 
derived.
    iii. The name of the virus(es) to which resistance is conferred.
    iv. When available, a unique identifier.
    EPA is proposing this notification requirement because it provides 
a mechanism that allows the Agency to keep a record of all PVCP-PIPs 
that may be sold or distributed. EPA expects that such a list would be 
useful to developers whose products are moving in international trade 
because it would enable EPA to post information on the United States 
Regulatory Agencies Unified Biotechnology Website (found at https://
usbiotechreg.nbii.gov/database_pub.asp) indicating that the developer 
has determined that the product satisfies the Agency's safety 
requirements. Such information can facilitate acceptance by importing 
countries. Absent such a posting, the field for EPA information would 
be blank, and importers might question the regulatory status of the 
product in the United States. In addition, EPA considers that such a 
list may be useful to the Agency for ensuring enforcement and 
compliance with FIFRA regulations because it will enable compliance 
personnel to ascertain the exemption status of products encountered in 
distribution and trade channels.
    2. Exemption by Agency determination. If a PVCP-PIP does not 
satisfy a particular criterion under paragraph (1) (i.e., Sec.  
174.27(a)(1), (b)(1), or (c)(1)), EPA proposes that as an alternative 
route to exemption, the product developer would submit data or other 
information to the Agency to demonstrate that a particular PVCP-PIP 
meets paragraph (2) of that criterion (i.e., it meets Sec.  
174.27(a)(2), (b)(2), or (c)(2), respectively). In addition, as part of 
this submission, a developer would also include a certification as to 
any determination that the product meets Sec.  174.27(a)(1), (b)(1), 
and/or (c)(1), as appropriate. During its review under Sec.  
174.27(a)(2), (b)(2), and/or (c)(2), EPA would not review the 
developer's determination that the product met any criterion under 
Sec.  174.27(a)(1), (b)(1), or (c)(1).
    EPA expects that in many instances developers would have most, if 
not all the information that would need to be included in any exemption 
submission under Sec. Sec.  174.27(a)(2), (b)(2), or (c)(2) because it 
would have been gathered in the course of product development or for 
submission to USDA/APHIS as part of a petition for determination for 
non-regulated status. EPA will consult with USDA in evaluating whether 
a PVCP-PIP meets the conditions for an Agency-determined exemption. EPA 
is proposing that information supporting the submission be maintained 
as records that will be available for EPA inspection as necessary for 
the duration of time that the PVCP-PIP is sold or distributed.
    EPA will evaluate the information contained in the submission and 
publish a notice allowing the public to comment on the Agency's 
determination that a product meets Sec.  174.27(a)(2), (b)(2), and/or 
(c)(2), as appropriate. EPA is providing such a public comment period 
because even though the public will have had the opportunity to comment 
through this proposal on the appropriateness of the criteria in Sec.  
174.27(a)(2), (b)(2), and (c)(2), the public would not otherwise have 
an opportunity to comment on whether a particular PVCP-PIP meets these 
criteria, given that these determinations depend on a case-by-case 
analysis of several types of information.
    The Agency plans to publish a Federal Register notice announcing 
its determination that a PVCP-PIP meets Sec.  174.27(a)(2), (b)(2), 
and/or (c)(2), and if no adverse comments are received during the 
comment period, the Agency's decision will be considered final, and EPA 
will publish no further notice. Based on its experience with EUP 
notices, EPA expects that, in general, determinations that a PVCP-PIP 
qualifies for exemption will be noncontroversial and generate no 
adverse comments. However, in the case of adverse comments, EPA would 
publish a subsequent Federal Register notice announcing its final 
determination and address all public comments. EPA would prefer 
criteria in Sec.  174.27(a)(2), (b)(2), and (c)(2) that would allow the 
public and PVCP-PIP developers to readily predict the outcome of an 
Agency review. Such criteria would reduce regulatory uncertainty in 
PVCP-PIP development and decrease the time EPA would need to evaluate 
the data/information necessary to make a determination that a PVCP-PIP 
meets a given criterion. However, using criteria for which 
determinations can be readily predicted might reduce the number of 
PVCP-PIPs that would qualify for exemption. EPA tried to balance these 
concerns and proposed multiple options when the Agency was unsure how 
to resolve this dilemma.
    However, EPA does not believe that the considerations underlying 
its decisions to grant the public a further opportunity to comment on 
the Agency's decision apply in cases where the Agency rejects a 
submission for an exemption. Accordingly, if EPA determines that the 
product fails to meet one or more of the exemption criteria, EPA will 
provide notice to the applicant of its decision on the submission and 
that a registration would be required for the PVCP-PIP before the PVCP-
PIP could be sold or distributed. The product developer may then submit 
an application for registration to the Agency. EPA would evaluate such 
PVCP-PIPs under the existing registration process and could implement 
conditions of use as appropriate.

B. Key Scientific Issues Associated with the Proposed Exemption 
Criteria under Sec.  174.27

    Several scientific questions concerning risk issues associated with 
PVCP-PIPs have been identified:
     What is the potential for a PVCP-PIP to endow plants with 
characteristics

[[Page 19597]]

that could disrupt the existing network of ecological relationships in 
managed, semi-managed, or natural ecosystems, e.g., through gene 
transfer to wild or weedy\1\ relatives? This issue is addressed at 
proposed Sec.  174.27(a) and is referred to as ``weediness'' for the 
purposes of this discussion.
---------------------------------------------------------------------------

    \1\ In the context of the phrase ``wild and weedy'' relatives/
plants used throughout this preamble, EPA considers weedy plants to 
be those with the characteristics of weeds, i.e., those that are 
considered undesirable, unattractive, or troublesome, especially 
when growing where they are not wanted. Wild plants are those that 
occur, grow, and live in a natural state and are not domesticated, 
cultivated, or tamed. EPA considers a naturalized population to be 
an enduring population of domesticated plants that grows in wild 
(non-cultivated) areas. EPA considers a native plant population to 
be one that originates in a particular region or ecosystem.
---------------------------------------------------------------------------

     What is the potential for interactions between a PVCP-PIP 
and an infecting virus to affect plant virus epidemiology or 
pathogenicity? This issue is addressed at proposed Sec.  174.27(b) and 
is referred to as ``viral interactions'' for the purposes of this 
discussion.
     What is the potential for exposure of humans or nontarget 
organisms to PVC-proteins with novel toxic or allergenic properties? 
This issue is addressed at proposed Sec.  174.27(c) and is referred to 
as ``protein production'' for the purposes of this discussion.
    These three questions are addressed below under the headings of 
weediness, viral interactions, and protein production, respectively.

C. Weediness

    1. Scientific issues. In evaluating whether a PVCP-PIP could alter 
ecological relationships among plants, EPA considered two primary 
issues: (1) whether the PVCP-PIP could endow a transgenic plant itself 
with an increased ability to spread into natural or semi-managed 
habitats and (2) whether the transfer of a PVCP-PIP from a transgenic 
plant into wild or weedy relatives could endow the wild or weedy 
relative with increased competitive ability and thus disrupt ecological 
relationships. Gene transfer among sexually compatible plants is a 
natural phenomenon that EPA does not consider to be an environmental 
risk per se. Whether the transfer of a PVCP-PIP could significantly 
disrupt ecological relationships in specific instances depends on all 
of the following considerations: First, does the crop plant containing 
the PVCP-PIP have wild relatives with which it is able to hybridize in 
nature? If it does not, there can be no gene transfer. Second, if there 
are sexually compatible relatives, is the gene conferring virus 
resistance likely to become stable in the population? Third, is the 
stable introduction of a PVCP-PIP into the plant population (i.e., 
introgression) likely to cause the population to become more weedy/
invasive or otherwise alter its competitive ability, thereby 
significantly changing the population dynamics of the plant community? 
The 2005 SAP concurred that these are important considerations for 
PVCP-PIPs by noting that an ``important ecological risk associated with 
gene flow from crop plants into their wild relatives is that the 
acquisition of crop genes might substantially alter the population 
dynamics of the wild plant. In particular, a transgene introgressed 
from the crop relative into a wild population might allow the wild 
species to persist in larger populations across a larger geographic 
range, or in a wider range of habitats. Collectively these changes in 
population dynamics can be considered `increased weediness'. The 
probability that a particular transgene will lead to increased 
weediness depends on the phenotype conferred by the transgene and on 
the ecological factor(s) currently limiting the size or distribution of 
the wild species. In particular, if the transgene alters plant response 
to the ecological factor limiting population size, then population 
dynamics may be affected. For PVCP-PIPs, the relevant consideration is 
whether virus resistance (conferred by the PVCP-PIP) leads to changes 
in the size or distribution of wild plant species with the PVCP-PIP'' 
(Ref. 11).
    i. Likelihood that a crop plant containing a PVCP-PIP could itself 
disrupt ecological relationships. In considering whether a PVCP-PIP 
could affect the ability of a plant to spread into natural or semi-
managed habitat at the margins of cultivated fields, i.e., to form 
feral or naturalized populations, the key consideration is whether 
viral infection is currently limiting the ability of agricultural crops 
to do so. The 2005 SAP pointed out that PVCP-PIPs ``are developed when 
virus infection of a crop reduces the crop yield, suggesting that virus 
infection is quite likely in naturalized populations of the crop as 
well'' (Ref. 11). However, virus infection in crop plants does not 
necessarily limit the spread of the crop into natural or semi-managed 
areas. As the 2005 Panel also noted, ``little is known about factors 
controlling population size in plant populations in general, including 
those that are currently stable, as well as those that are currently 
weedy or invasive'' (Ref. 11). Few published studies are available that 
evaluate this question directly, perhaps due to the general rarity of 
negative results in scientific literature. However, one study did find 
virus infection to have little effect on an agricultural crop. Field 
experiments with transgenic virus-resistant sugar beets revealed no 
competitive advantage (measured as seedling emergence and biomass 
production) between the transgenic and susceptible control lines (Ref. 
12).
    Although virus infection has been shown to negatively impact growth 
and/or reproduction of some natural plant communities (discussed below 
in Unit III.C.1.ii.), EPA recognizes that there is reason to question 
whether the situation would be different for crop plants. The National 
Research Council (NRC) noted in 1989 that most naturalized, 
domesticated crops generally are unable to effectively compete with 
wild species in natural ecosystems and have not been known to acquire 
this ability with the type of single-gene traits commonly introduced 
through genetic modification (Ref. 13). The 1989 NRC report went on to 
note that plant breeders have capitalized for decades on the fact that 
relatively minor genetic changes can produce plants with altered 
ecological properties, but the addition of pest resistant traits has 
not been known to result in increased weediness of widely used crops 
(Ref. 13). A 1989 survey of the weedy characteristics of crop versus 
weed species showed that weeds possess significantly more weedy 
characteristics on average than do crop plants (Ref. 14). For 
domesticated crops, the traits that make them useful to humans also 
reduce their competitive ability in nonagricultural habitats. Crops 
that have been subjected to long-term breeding (e.g., corn and 
soybeans) are unlikely to possess characteristics that would allow the 
plant to compete effectively outside of managed ecosystems. Domesticity 
arises because intensive breeding efforts seek to eliminate many 
characteristics of the crop plant that would enhance weediness (e.g., 
seed shattering, thorns, seed dormancy, and bitterness). For example, 
lack of seed shattering and seed dormancy greatly reduces the ability 
of an annual crop to persist without human intervention. Highly 
domesticated crops such as corn are thus unlikely to survive for 
multiple generations outside agricultural fields no matter what 
transgenic trait they contain, including virus resistance (Ref. 15).
    However, some crop species, e.g., cranberry and blackberry may have 
more similarities to their wild relatives than highly domesticated 
crops such as corn or soybean. As noted by the 2005

[[Page 19598]]

SAP, ``Determining whether a particular crop can naturalize and then 
spread as a weedy species is difficult to ascertain from the literature 
and determining the probability that a crop will be more weedy or 
invasive if it contains a PVCP-PIP is even more difficult'' (Ref. 11). 
Such determinations may therefore need to rely on information not 
available in public literature as part of a risk assessment for a 
particular plant. Plants, such as forest trees, that may grow for many 
years in natural environments or in very close proximity to natural 
environments present additional difficulty in evaluating and managing 
risks (Ref. 16). The period of time over which such plants would 
persist is significantly longer than for annual, short-lived species. 
Individual plants will therefore experience a much wider range and 
variety of stress conditions, enemy attacks, and climate change, making 
predictions about naturalization potential with acquired virus 
resistance particularly challenging.
    Thus, although EPA believes that many crop species are unlikely to 
disrupt ecological relationships through acquisition of a PVCP-PIP, the 
available information is insufficient to support the general 
conclusions that EPA would need to make for a categorical exemption of 
PVCP-PIPs. EPA would need to conclude that there is a low risk that 
acquisition of a PVCP-PIP would significantly affect the 
competitiveness of any of the plants currently grown as crops and that 
none of these crop species would significantly disrupt ecological 
relationships when modified to contain a PVCP-PIP. Therefore, the 
Agency believes that it is necessary to evaluate each plant species 
independently to consider whether it is likely to establish weedy or 
invasive populations outside of agricultural fields in the United 
States and thereby potentially significantly disrupt ecological 
relationships if it becomes virus resistant due to a PVCP-PIP. Factors 
likely to influence this determination cannot be readily distilled into 
a straightforward criterion suitable for a categorical exemption.
    ii. Likelihood that a crop plant containing a PVCP-PIP could 
significantly disrupt ecological relationships through gene transfer. 
The question of whether gene transfer from a crop to a wild or weedy 
relative could significantly disrupt ecological relationships is a more 
complicated question because a much broader range of potential plants 
may be involved when wild or weedy relatives are considered in addition 
to the crops themselves. The answer to this question depends first on 
the question of whether the transgenic crop plants could transfer a 
PVCP-PIP to other plant populations. This potential for transfer 
depends in part on the frequency of hybridization between domesticated 
species and their wild relatives. Hybridization is affected by the 
ability of plants to cross-pollinate which in turn is affected by their 
timing of reproductive viability and the proximity of the plants. 
Hybridization is also affected by the ability of pollen to fertilize 
recipient plants, the recipient plants to develop viable seeds, these 
seeds to germinate, and the seedlings to grow into viable adults (Ref. 
17). In spite of these potential constraints, a survey of the world's 
most important crops suggests that spontaneous hybridization of 
domesticated plants with wild relatives appears to be a general feature 
across at least a portion of the worldwide geographic area over which 
each is cultivated (Refs. 18 and 19). The ability to cross crops with 
wild relatives (which may not necessarily occur where the crop is 
grown) is also the basis of many traditional breeding techniques that 
are used for virtually all crops (Ref. 20).
    Whether virus infection limits the growth and/or reproductive 
ability of wild or weedy plant populations is more diffic