Watermelon Mosaic Virus-2 Coat Protein, Zucchini Yellow Mosaic Virus Coat Protein and the Genetic Material Necessary for Production of These Proteins in Transgenic Squash Plants; Tolerance Exemption

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 180

[PP 4E4310/P585; FRL-4898-5]

RIN 2070-AC18

Watermelon Mosaic Virus-2 Coat Protein, Zucchini Yellow Mosaic

Virus Coat Protein and the Genetic Material Necessary for Production of

These Proteins in Transgenic Squash Plants; Tolerance Exemption

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This document proposes establishing an exemption from the

requirement for a tolerance under the Federal Food, Drug, and Cosmetic

Act for residues of the plant-pesticides watermelon mosaic virus-2

(WMV2) coat protein and zucchini yellow mosaic virus (ZYMV) coat

protein, as expressed in Asgrow line ZW20 of Cucurbita pepo L. and the

genetic material necessary for the production of these proteins. This

exemption was requested by Asgrow Seed Co.

DATES: Written comments, identified by the document control number [PP

4E4310/P585], must be received on or before August 26, 1994.

ADDRESSES: By mail, submit written comments to: Public Response and

Program Resources Branch, Field Operations Division (7506C), Office of

Pesticide Programs, Environmental Protection Agency, 401 M St., SW.,

Washington, DC 20460. In person, bring comments to: Rm. 1128, CM #2,

1921 Jefferson Davis Hwy., Arlington, VA 22202.

Information submitted as a comment concerning this document may be

claimed confidential by marking any part or all of that information as

``Confidential Business Information'' (CBI). Information so marked will

not be disclosed except in accordance with procedures set forth in 40

CFR part 2. A copy of the comment that does not contain CBI must be

submitted for inclusion in the public record. Information not marked

confidential may be disclosed publicly by EPA without prior notice. All

written comments will be available for public inspection in Rm. 1128 at

the Virginia address given above, from 8 a.m. to 4 p.m., Monday through

Friday, excluding legal holidays.

FOR FURTHER INFORMATION CONTACT: By mail: Steve Robbins, Product

Manager (PM) 21, Registration Division (7505C), Environmental

Protection Agency, 401 M St., SW., Washington, DC 20460. Office

location and telephone number: Rm. 227, CM #2, 1921 Jefferson Davis

Hwy., Arlington, VA 22202, (703)-305-6900.

SUPPLEMENTARY INFORMATION: EPA received from Asgrow Seed Co., Kalamzoo,

MI 49004, pesticide petition (PP) 4E4310 on December 6, 1993, proposing

to amend 40 CFR part 180 by establishing a regulation pursuant to the

Federal Food, Drug and Cosmetic Act, 21 U.S.C. 346a, to exempt from the

requirement of a tolerance, the residues of the plant-pesticides

watermelon mosaic virus-2 coat protein and zucchini yellow mosaic virus

coat protein as expressed in Asgrow line ZW20 of Cucurbita pepo L., and

subsequent generations obtained through normal sexual reproduction. An

amendment to this petition was received on April 4, 1994, which changed

the proposed exemption by including the genetic material necessary for

the production of these proteins.

The squash plants identified as Asgrow line ZW20 have been

genetically modified to produce the coat proteins of two viruses which

commonly infect squash plants (watermelon mosaic virus-2 and zucchini

yellow mosaic virus). Production of specific viral coat proteins by the

plant will protect it from infection by those viruses. Viral coat

proteins, along with the genetic material (nucleic acids) necessary to

produce them in the plant, are designated as plant pesticides by EPA.

The data submitted in the petition and all other relevant material

have been evaluated. The data considered in support of the exemption

from the requirement of a tolerance include the following: Sequences of

the engineered WMV2 and ZYMV coat protein coding regions and their

resulting coat proteins, Southern blots to show absence of NPT2 gene

and non-T-DNA sequences in ZW 20 squash, levels of WMV2 and ZYMV coat

protein deduced from amino acid sequence, and levels of viral coat

proteins in fruit collected from local markets.

The Agency agrees with the petitioner's contention that components

of plant pathogenic viruses, as represented by the protein coats of

zucchini yellow mosaic virus and watermelon mosaic virus-2, present no

health concerns when expressed in edible portions of the plant. The

data include evidence to support the lack of any NPT2 marker gene in

the ZW20 plants. Therefore, the only transgene expressed is the viral

coat protein. The submitted data include results of tests to determine

the levels of the proteins in market-ready fruit from line ZW20 and

related this information to the normal levels of these viruses in

cucurbit fruits pruchased at local markets. These data demonstrated

that, overall, the levels of viral coat proteins in locally grown

cucurbit plants were higher than those expressed in the transgenic

squash.

The exemption from the requirement of a tolerance for specific

viral coat proteins WMV2 and ZYMV is based on the following: (1) Virus-

infected plants have always been a part of the human and domestic

animal food supply since most crops are frequently infected with plant

viruses, and food from these crops has been and is being consumed

without observed adverse human health effects; (2) plant viruses have

never been shown to be infectious to humans or mammals. Plant viruses

are not able to replicate in mammals or other vertebrates. Thus, there

is no possibility of human infection. In addition, only the portion of

the viral genome coding for the whole coat protein or a subcomponent of

the coat protein will be expressed in the ZW20 plants. This portion by

itself is incapable of forming infectious particles. Since whole intact

plant viruses are not known to cause deleterious human health effects,

it is reasonable to assume that a subunit of these viruses likewise

will not cause adverse human health effects.

Asgrow Seed Co. amended its petition to include the genetic

material necessary for the production of the proteins because EPA

considers such genetic material to be part of the plant-pesticide

product. It is the genetic material that is introduced into the plant

with the intent that it will ultimately result in a pesticidal effect

(i.e., the plant will produce the viral coat protein). Moreover, the

pesticidal proteins could not be produced without the genetic material

being present in the plant. The exemption from a tolerance for the

genetic material which codes for the production of the viral coat

proteins is based on the fact that the nucleic acids which form the

genetic material are found in all foods and have not, by themselves,

been associated with toxic or pathogenic effects on animals and humans.

None of these constituents of nucleic acids are know to be acute

toxicants by themselves but, like proteins and other normal

constituents of food, may cause indirect, adverse metabolic effects if

consumed exclusively at high doses over a long period of time in the

absence of a normal balanced diet. Nucleic acids will not occur at

these high amounts in ZW20 plants. Thus, EPA does not believe there is

any potential for adverse health effects related to the consumption of

the ZW20 plants.

The data and information submitted with this petition are

acceptable and are adequate to show that there are no forseeable human

or domestic health hazards likely to arise from the consumption of

fruit from the Asgrow line ZW20 of Cucurbita pepo L.

Acceptable daily intake (ADI) and maximum permissible intake (MPI)

considerations are not relevant to this petition because the data

submitted demonstrate that these plant pesticides are not toxic to

humans. No enforcement actions are expected based upon the level of

residues of viral coat proteins and the genetic material necessary for

their production. Therefore, the requirement for an analytical method

for enforcement purposes is not applicable to this exemption request.

This will be the first exemption from the requirement of a tolerance

for this plant pesticide.

The plant pesticides in the Asgrow squash line ZW20 are considered

useful for the purpose for which the exemption from the requirement of

a tolerance is sought. Based on the information considered, the Agency

concludes that establishment of the exemption will protect the public

health. Therefore, the regulation is proposed as set forth below.

Interested persons are invited to submit written comments on the

proposed rule. Comments must bear a notation indicating the document

control number, [PP 4E4310/P585]. All written comments filed in

response to this petition will be available in the Public Response and

Program Resources Branch at the address given above from 8 a.m. to 4

p.m., Monday through Friday, except legal holidays.

The Office of Management and Budget has exempted this rule from the

requirements of section 2 of Executive Order 12866.

Pursuant to the requirements of the Regulatory Flexibility Act

(Pub. L. 96-354, 94 Stat. 1164, 5 U.S.C. 601-612), the Administrator

has determined that regulations establishing new tolerances or raising

tolerance levels or establishing exemptions from tolerance requirements

do not have an economic impact on a substantial number of small

entities. A certification statement to this effect was published in the

Federal Register of May 4, 1981 (46 FR 24950).

Interested persons are invited to submit written comments on the

proposed rule. Comments must bear a notation indicating the document

control number [PP 4E4310/P585]. All written comments filed in response

to this petition will be available in the Public Response and Program

Resources Branch at the address given above from 8 a.m. to 4 p.m.,

Monday through Friday, except legal holidays.

The Office of Management and Budget has exempted this rule from the

requirements of section 2 of Executive Order 12866.

Pursuant to the requirements of the Regulatory Flexibility Act

(Pub. L. 96-354, 94 Stat. 1164, 5 U.S.C. 601-612), the Administrator

has determined that regulations establishing new tolerances or raising

tolerance levels or establishing exemptions from tolerance requirements

do not have an economic impact on a substantial number of small

entities. A certification statement to this effect was published in the

Federal Register of May 4, 1981 (46 FR 24950).

List of Subjects in 40 CFR Part 180

Environmental protection, Administrative practice and procedure,

Agricultural commodities, Food additives, Pesticides and pests,

Processed foods, Reporting and recordkeeping requirements.

Dated: July 11, 1994.

Lois Rossi,

Acting Director, Registration Division, Office of Pesticide Programs.

Therefore, it is proposed that 40 CFR part 180 be amended as

follows:

PART 180--[AMENDED]-

1. The authority citation for part 180 continues to read as

follows:

Authority: 21 U.S.C. 346a and 371.

2. In subpart D, by adding new Sec. 180.1132, to read as follows:

Sec. 180.1132 Watermelon mosaic virus-2 coat protein, zucchini yellow

mosaic virus coat protein and the genetic material necessary for the

production of these proteins; exemption from the requirement of a

tolerance.

The plant-pesticides watermelon mosaic virus-2 coat protein and

zucchini yellow mosaic virus coat protein as expressed in Asgrow line

ZW20 of Cucurbita pepo L. and the genetic material (nucleic acids)

necessary for the production of these proteins are exempted from the

requirement of a tolerance in this transgenic plant and in subsequent

generations of Asgrow line ZW20 of cucurbita pepo L. obtained through

normal sexual reproduction.

[FR Doc. 94-17912 Filed 7-26-94; 8:45 am]

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