[Federal Register Volume 62, Number 16 (Friday, January 24, 1997)]
[Notices]
[Pages 3682-3685]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-1754]


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ENVIRONMENTAL PROTECTION AGENCY
[PF-660; FRL-5380-2]


DeKalb Genetics Corporation; Pesticide Tolerance Petitions 
Filings

AGENCY: Environmental Protection Agency (EPA).
ACTION: Notice of filing.

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SUMMARY: This notice announces the filing of pesticide petitions 
proposing regulations establishing exemptions from the requirement of a 
tolerance for residues of the active ingredient plant-pesticide 
Bacillus thuringiensis subsp. kurstaki CrylA(c) protein and the genetic 
material necessary for the production of this protein in or on all raw 
agricultural commodities and the inert ingredient plant-pesticide 
phosphinothricin acetyltransferase protein and the genetic material 
necessary for the production of this protein in or on all raw 
agricultural commodities. This notice includes a summary of the 
petition that was prepared by the petitioner, DeKalb Genetics 
Corporation.

DATES: Comments, identified by the docket number PF-660, must be 
received on or before February 24, 1997.

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. 1132, Crystal 
Mall #2, 1921 Jefferson Davis Hwy., Arlington, VA.
    A record has been established for this notice document under docket 
number PF-660 (including any comments and data submitted electronically 
as described below). A public version of this record, including 
printed, paper versions of electronic comments, which does not include 
any information claimed as CBI, is available for inspection from 8:30 
a.m. to 4 p.m., Monday through Friday, excluding legal holidays. The 
public record is located in the Public Response and Program Resources 
Branch, Field Operations Division (7506C), Office of Pesticide 
Programs, Environmental Protection Agency, Rm. 1132, Crystal Mall #2, 
1921 Jefferson Davis Highway, Arlington, VA.
    Comments and data may also be submitted electronically by sending 
electronic mail (e-mail) to: [email protected] or by 
submitting disks. Electronic comments must be submitted either in ASCII 
format (avoiding the use of special characters and any form of 
encryption) or in WordPerfect in 5.1 file format. All comments and data 
in electronic form must be identified by the docket number PF-660. 
Electronic comments on this notice may be filed online at many Federal 
Depository Libraries. The official record for this rulemaking, as well 
as the public version described above, will be kept in paper form. 
Accordingly, EPA will transfer all comments received electronically 
into printed, paper form as they are received and will place the paper 
copies in the official rulemaking record, which will also include all 
comments submitted directly in writing.
    Information submitted as a comment concerning this notice 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. No CBI should be submitted through e-mail. 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.


[[Page 3683]]


FOR FURTHER INFORMATION CONTACT: Mike Mendelsohn, Biopesticides and 
Pollution Prevention Division (7501W), Office of Pesticide Programs, 
Environmental Protection Agency, 401 M St., SW., Washington, DC 20460. 
Office location, telephone number, and e-mail address: 5th Floor, CS 
B1, 2805 Jefferson Davis Hwy., Arlington, VA, 703-308-8715; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION: EPA has received pesticide petitions (PP) 
6E4710 and 6F4711 from DeKalb Genetics Corporation (Dekalb), 3100 
Sycamore Road, DeKalb, IL 60115. The petitions propose, pursuant to 
section 408 of the Federal Food, Drug, and Cosmetic Act (FFDCA), 21 
U.S.C. 346a, to amend 40 CFR part 180 to establish exemptions from the 
requirement of a tolerance for the plant-pesticides Bacillus 
thuringiensis subsp. kurstaki CrylA(c) protein and the genetic material 
necessary for the production of this protein in or on all raw 
agricultural commodities and phosphinothricin acetyltransferase protein 
and the genetic material necessary for the production of this protein 
in or on all raw agricultural commodities. EPA has determined that the 
petition contains data or information regarding the elements set forth 
in section 408(d)(2); however, EPA has not fully evaluated the 
sufficiency of the submitted data at this time or whether the data 
supports granting of the petition. Additional data may be needed before 
EPA rules on the petition.
    Dekalb has stated that analytical methods for the detection and 
measurement of the CryIA(c) and PAT proteins are not needed since they 
are petitioning for exemptions from the requirement of a tolerance on 
the basis of mammalian safety.
    As required by section 408(d) of the FFDCA, as recently amended by 
the Food Quality Protection Act, Dekalb included in the petition a 
summary of the petition and authorization for the summary to be 
published in the Federal Register in a notice of receipt of the 
petition. The summary represents the views of Dekalb; EPA, as mentioned 
above, is in the process of evaluating the petition. As required by 
section 408(d)(3) EPA is including the summary as a part of this notice 
of filing. EPA may have made minor edits to the summary for the purpose 
of clarity.

I. Petition Summary for PP 6F4711

    This unit summarizes information cited by DeKalb to support the 
proposed tolerance exemption for Bacillus thuringiensis subsp. kurstaki 
CryIA(c) protein and the genetic material necessary for the production 
of this protein in or on all raw agricultural commodities when used as 
a plant-pesticide active ingredient.

A. Bacillus thuringiensis subsp. kurstaki CryIA(c) Protein Uses

    Corn, Zea mays L., has been genetically engineered to be resistant 
to Lepidopteran insect pests. Insect protection was accomplished by 
insertion of the cryIA(c) gene from Bacillus thuringiensis subsp. 
kurstaki which encodes a protein that is specifically insecticidal to 
Lepidopteran insect larvae but Dekalb believes is safe to nontarget 
organisms such as mammals, birds, fish, and nontarget insects. CryIA(c) 
protein is used as a ``plant-pesticide'' in transgenic corn plants to 
control Lepidopteran insects including European corn borer. CryIA(c) 
corn will be deployed in situations where Lepidopteran insect control 
is important.

B. Product Identity and Chemistry

    Product analysis data demonstrated that microbially expressed and 
purified CryIA(c) delta endotoxin used for mammalian toxicological 
testing purposes is not significantly different than the delta 
endotoxin expressed in the plant. The following assays were used to 
determine the similarity of the microbially expressed and purified 
CryIA(c) delta endotoxin and that produced in corn: SDS-PAGE, Western 
blots, amino acid sequencing, testing for post translational 
modification, and insect bioactivity. These assays demonstrated that 
the truncated CryIA(c) delta endotoxin expressed in corn and the 
tryptic core of the microbially-produced CryIA(c) endotoxin are 
similar.

C. Mammalian Toxicological Profile

    The CryIA(c) protein produced in transgenic corn is the tryptic 
core of CryIA(c) found in nature and used in Bacillus thuringiensis 
susp. kurstaki microbial formulations that have been registered with 
the EPA and have been commercially available for over 30 years. To be 
active against the target insect, CryIA(c) protein must be ingested. In 
the insect gut, the protein binds to specific receptors in the insect 
mid-gut, inserts into the membrane and forms ion-specific pores. These 
events disrupt the digestive processes and cause the death of the 
insect. There are no receptors for the protein delta endotoxins of 
Bacillus thuringiensis subspecies on the surface of mammalian 
intestinal cells; therefore humans are not susceptible to these 
proteins.
    The mammalian toxicological data submitted in support of the 
exemption from the requirement for a tolerance include an acute oral 
toxicity study with mice and a test for digestibility under simulated 
gastric conditions. The results of these studies demonstrate that 
CryIA(c) protein has an acute LD50 greater than 3,325 mg/kg. In 
tests for digestibility in simulated gastric fluid, CryIA(c) protein 
was found to degrade to below detectable levels within a few seconds 
when exposed to full strength gastric fluid. When exposed to simulated 
gastric fluid that had been diluted 100-fold, CryIA(c) protein degraded 
to below detectable levels in five minutes. Given the rapid 
digestibility of CryIA(c) delta endotoxin, no chronic effects are 
expected. CryIA(c) delta endotoxin, or metabolites of the endotoxin are 
not known to, or expected to have any effect on the immune or endocrine 
systems. Proteins in general are not carcinogenic, therefore, no 
carcinogenic risk is associated with the CryIA(c) protein.
    Current scientific knowledge suggests that common food allergens 
tend to be resistant to degradation by heat, acid, and proteases and 
are glycosylated and present at high concentrations in food. CryIA(c) 
delta endotoxin is rapidly degraded by simulated gastric fluid, is not 
present as a major component in food, and is apparently nonglycosylated 
or otherwise post-translationally modified when produced in plants. 
Despite decades of widespread use of Bacillus thuringiensis as a 
pesticide (it has been registered since 1961), there have been no 
confirmed reports of immediate or delayed allergic reactions to the 
delta endotoxins despite significant oral, dermal, and inhalation 
exposure to microbial products containing the delta endotoxins.
    The genetic material necessary for the production of Bacillus 
thruringiensis CryIA(c) delta endotoxin are nucleic acids (DNA) which 
comprise the genetic material encoding the CryIA(c) delta endotoxin and 
the regulatory regions associated with the gene. Regulatory regions are 
the genetic material that control the expression of the genetic 
material encoding the CryIA(c) delta endotoxin, such as promoters, 
terminators, introns, and enhancers. DNA is common to all forms of 
plant and animal life, and there are no known instances of where 
nucleic acids have been associated with toxic effects related to their 
consumption. The nucleic acids introduced into CryIA(c) corn have been 
characterized. No mammalian toxicity is expected from dietary exposure 
to the genetic material necessary for the production of the

[[Page 3684]]

Bacillus thuringiensis CryIA(c) endotoxin in corn.

D. Aggregate Exposure

    Exposure via dermal exposure or inhalation is unlikely given that 
the delta endotoxin is contained in plant cells. Transfer of the 
pesticide to drinking water is highly unlikely given that CryIA(c) 
protein has been shown to degrade in senescing corn plants and Bt 
proteins are known to rapidly degrade in the soil. Oral exposure, at 
very low levels, may occur from ingestion of processed corn products 
however the lack of mammalian toxicity, and the digestibility of the 
protein have been demonstrated.

E. Cumulative Exposure

    Consideration of a common mode of toxicity is not appropriate given 
that there is no indication of mammalian toxicity of CryIA(c) protein 
and no information that indicates that toxic effects would be 
cumulative with any other compounds.

F. Safety Determination

    1. U.S. population in general. The lack of acute toxicity and the 
rapid digestibility of CryIA(c) delta endotoxin provides evidence for 
the lack of toxicity and allergenicty and Dekalb believes support an 
exemption from the requirement for a tolerance for Bacillus 
thuringiensis subsp. kurstaki CryIA(c) protein. Bacillus thuringiensis 
subsp. kurstaki delta endotoxins have been used in microbial 
insecticide formulations that have been registered by the EPA and 
commercially available since the early 1960s.
    2. Infants and children. The use sites for CryIA(c) delta endotoxin 
are all agricultural for control of Lepidopteran insects. Therefore, 
nondietary exposure to infants and children is not expected. Dekalb 
believes that the lack of toxicity of CryIA(c) delta endotoxin and 
history of safe use of Bacillus thruringiensis subsp. kurstaki delta 
endotoxins provides reasonable certainty that no harm will result to 
infants and children from aggregate dietary exposure to residues of 
CryIA(c).

G. Existing Tolerances or Tolerance Exemptions

    An exemption from the requirement for a tolerance was granted by 
the EPA for ``Plant-pesticide Bacillus thuringiensis CryIA(c) Delta-
Endotoxin and the Genetic Material Necessary for Its Production in 
Cotton,'' Federal Register: September 15, 1995, (60 FR 47871; FRL-4976-
9).

II. Petition Summary for PP 6E4710

    This unit summarizes information cited by DeKalb to support the 
proposed tolerance exemption for phosphinothricin acetyltransferase 
protein and the genetic material necessary for the production of this 
protein in or on all raw agricultural commodities when used as a plant-
pesticide inert ingredient.

A. Phosphinothricin Acetyltransferase Protein Uses

    Phosphinothricin acetyltransferase or PAT protein, is used as 
``plant-pesticide inert ingredient'' in transgenic, insect protected 
corn plants. PAT functions as a selectable marker and as well as a 
source of resistance to glufosinate herbicides. PAT protein is encoded 
by the bar gene, originally cloned from a common soil bacterium, 
Streptomyces hygroscopicus. Insect protected corn will be deployed in 
situations where Lepidopteran insect control is important.

B. Product Identity and Chemistry

    Product analysis data demonstrated that microbially expressed and 
purified PAT protein used for mammalian toxicological testing purposes 
is not significantly different than the PAT protein expressed in the 
plant. The following assays were used to determine the similarity of 
the microbially expressed and purified PAT protein and that produced in 
corn: SDS-PAGE,Western blots, amino acid sequencing and testing for 
post translational modification. These assays demonstrated that the PAT 
protein expressed in corn and PAT protein produced in and purified from 
a microbial source are similar.

C. Mammalian Toxicological Profile

    The PAT enzyme catalyzes the transfer of an acetyl group from 
acetyl CoA to the amino group of phosphinothricin (also known as 
glufosinate). The enzyme is highly substrate specific. Dekalb believes 
it is therefore highly unlikely that PAT will acetylate any naturally 
occurring compound in maize cells.
    The mammalian toxicological data submitted in support of the 
exemption from the requirement for a tolerance include an acute oral 
toxicity study with mice and a test for digestibility under simulated 
gastric conditions. The results of these studies demonstrate that PAT 
protein has an acute LD50 greater than 2,500 mg/kg. In tests for 
digestibility in simulated gastric fluid, PAT protein was found to 
degrade to below detectable levels within 2 minutes when exposed to 
full strength gastric fluid. When exposed to simulated gastric fluid 
that had been diluted 100-fold, PAT protein degraded to below 
detectable levels in 5 minutes. Given the rapid digestibility of PAT 
protein, no chronic effects are expected. PAT protein or metabolites 
protein are not known to, or expected to have any effect on the immune 
or endocrine systems. Proteins in general are not carcinogenic, 
therefore, no carcinogenic risk is associated with the PAT protein.
    Current scientific knowledge suggests that common food allergens 
tend to be resistant to degradation by heat, acid, and proteases and 
are glycosylated and present at high concentrations in food. PAT 
protein is rapidly degraded by simulated gastric fluid, is not present 
as a major component in food, and is apparently nonglycosylated or 
otherwise post-translationally modified when produced in plants.
    The genetic material necessary for the production of PAT protein 
are nucleic acids (DNA) which comprise the genetic material encoding 
the PAT protein and the regulatory regions associated with the gene. 
Regulatory regions are the genetic material that control the expression 
of the genetic material encoding the PAT protein, such as promoters, 
terminators, introns, and enhancers. DNA is common to all forms of 
plant and animal life, and there are no known instances of where 
nucleic acids have been associated with toxic effects related to their 
consumption. The nucleic acids introduced into insect protected corn 
have been characterized. No mammalian toxicity is expected from dietary 
exposure to the genetic material necessary for the production of the 
PAT protein in corn.

D. Aggregate Exposure

    Exposure via dermal exposure or inhalation is unlikely given that 
the PAT protein is contained in plant cells. Transfer of the pesticide 
to drinking water is highly unlikely given that PAT protein is 
undetectable in pollen, has been shown to degrade in senescing corn 
plants. Oral exposure, at very low levels, may occur from ingestion of 
processed corn products; however, Dekalb believes that the lack of 
mammalian toxicity, and the digestibility of the protein have been 
demonstrated.

E. Cumulative Exposure

    Dekalb believes that consideration of a common mode of toxicity is 
not appropriate given that there is no indication of mammalian toxicity 
of PAT protein and no information that indicates that toxic effects 
would be cumulative with any other compounds.

[[Page 3685]]

F. Safety Determination

    1. U.S. population in general. Dekalb believes that the lack of 
acute toxicity and the rapid digestibility of PAT protein provide 
evidence for the lack of toxicity and allergenicty and support an 
exemption from the requirement for a tolerance for PAT protein.
    2. Infants and children. The use sites for insect protected corn 
containing PAT protein are all agricultural for control of Lepidopteran 
insects. Therefore, nondietary exposure to infants and children is not 
expected. Dekalb believes that the lack of toxicity of PAT protein 
provides reasonable certainty that no harm will result to infants and 
children from aggregate dietary exposure to residues of PAT.

G. Existing Tolerances or Tolerance Exemptions

    An exemption from the requirement for a tolerance was granted by 
the EPA for ``Plant-pesticide Inert Ingredient Phosphinothricin 
Acetyltransferase (PAT) and the Genetic Material Necessary for Its 
Production (Plasmid Vector pCIBP3064) in Corn,'' Federal Register: 
August 16, 1995, (60 FR 42450; FRL-4971-2).

III. Administrative Matters

    EPA invites interested persons to submit comments on this notice of 
filing. Comments must bear a notification indicating the document 
control number [PF-660]. 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 8:30 a.m. to 4 p.m., Monday 
through Fridy, except legal holidays.
    A record has been established for this notice under docket number 
[PF-660] (including comments and data submitted electronically as 
described below). A public version of this record, including printed, 
paper versions of electronic comments, which does not include any 
information claimed as CBI, is available for inspection from 8:30 a.m. 
to 4 p.m., Monday through Friday, excluding legal holidays. The public 
record is located in Rm. 1132 of the Public Response and Program 
Resources Branch, Field Operations Division (7506C), Office of 
Pesticide Programs, Environmental Protection Agency, Crystal Mall #2, 
1921 Jefferson Davis Highway, Arlington, VA.
    Electronic comments can be sent directly to EPA at:
    [email protected]

    Electronic comments must be submitted as an ASCII file avoiding the 
use of special characters and any form of encryption.
    The official record for this rulemaking, as well as the public 
version, as described above will be kept in paper form. Accordingly, 
EPA will transfer all comments received electronically into printed, 
paper form as they are received and will place the paper copies in the 
official rulemaking record which will also include all comments 
submitted directly in writing. The official rulemaking record is the 
paper record maintained at the address in ``ADDRESSES'' at the 
beginning of this document.

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

List of Subjects

    Environmental protection, Agricultural commodities, Pesticides and 
pests, Reporting and recordkeeping.

    Dated: January 17, 1997.

Flora Chow,

Acting Director, Biopesticides and Pollution Prevention Division, 
Office of Pesticide Programs.

[FR Doc. 97-1754 Filed 1-23-97; 8:45 am]
BILLING CODE 6560-50-F