United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7504C)
EPA-738-F-95-020
June 1995
R.E.D. FACTS
Pesticide
Reregistration
Agrobacterium
radiobacter
All pesticides sold or distributed in the United States must be registered
by EPA, based on scientific studies showing that they can be used without
posing unreasonable risks to people or the environment. Because of advances
in scientific knowledge, the law requires that pesticides which were first
registered years ago be reregistered to ensure that they meet today's more
stringent standards.
In evaluating pesticides for reregi strati on, EPA obtains and reviews a
complete set of studies from pesticide producers, describing the human health
and environmental effects of each pesticide. The Agency imposes any
regulatory controls that are needed to effectively manage each pesticide's
risks. EPA then reregisters pesticides that can be used without posing
unreasonable risks to human health or the environment.
When a pesticide is eligible for reregistration, EPA announces this and
explains why in a Reregistration Eligibility Decision (RED) document. This
fact sheet summarizes the information in the RED document for reregistration
case 4101, Agrobacterium radiobacter., also referred to as A radiobacter.
Use Profile Agrobacterium radiobacter is a fungicide (microbial control agent) used to
control Crown Gall in certain non-bearing fruit, nut and ornamental nursery
stock.
Non-bearing Fruit and Nut Nursery Stock:
Almonds
Blueberries
Cherries
Peaches
Plums
Apples
Caneberries*
Kiwis
Pears
Prunes
Apricots
Cranberries
Nectarines
Pecans
Walnuts
Caneberries include Blackberries, Boysenberries, Raspberries, and Youngberries.
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Ornamental Nursery Stock:
Euonymus Rose
Weeping Cherry
Formulations include a 2.25% flowable concentrate product and a 1.2 %
solidified agar product.
Agrobacterium radiobacter is applied by hand operated spray, drench and dip
treatment equipment.
Method and Rate -
Dipping
Germinating Seed Application - 1 unit of product**/gallon of water.
Seedling Application - 1 unit of products/gallon of water.
Cutting Application - 1 unit of product**/gallon of water.
Root and Stem Application - 1 unit of product**/gallon of water.
Spraying
Root and Stem Application - 1 unit of product**/gallon of water.
Soil Drench Application - 1 unit of product**/ 5 gallons of water; 6-8 oz of
suspension per 1 gallon container or 1 foot of plant row.
**1 unit of product equals 3 x 1012 and 1.2 x 1011 colony forming units per volume
of product for the flowable concentrate and solidified agar formulations, respectively.
Timing - Preplant — cutting, root and stem treatments; Immediately Prior to
Planting — germinating seed and seedling treatments; Postplant — soil drench
treatment.
Amount- Less than 1,000 pounds of this active ingredient (a.i.) are used
annually.
Use practice limitations: Label limits use only to applications on certain non-
food and non-bearing plants.
Regulatory
History
Agrobacterium radiobacter was first registered as a pesticide in the U.S.
in 1979. During Phase 3 of the Reregi strati on Process, the toxicology data
base for A. radiobacter was evaluated and determined to adequately satisfy
most of the data requirements for microbial pest control agents. Acute
pulmonary toxicity/pathogenicity studies, and acute intravenous
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toxicity/pathogenicity studies were identified as outstanding data gaps and a
Data Call-In was issued July 1993. Since the DCI, the Agency's initial
position with respect to these guidelines was re-evaluated, and these data
requirements were waived because it was determined that A. radiobacter was
a soil saprophyte and was not known to be pathogenic to humans and animals.
Currently, two A radiobacter products are registered: Galltrol-A and
Norbac 84-C.
Human Health
Assessment
Toxicity
In studies using laboratory animals, A. radiobacter generally has been
shown to be of very low acute toxicity. It's primary eye irritation/infection
toxicity places it in Toxicity Category III (the second lowest of four
categories). Agrobacterium radiobacter's oral toxicity is LD50 > 5g/Kg,
which places it in Toxicity Category IV (the lowest of four categories).
Likewise, A. radiobacter's acute dermal toxicity is in Toxicity Category IV.
Dietary Exposure
Although A. radiobacter is applied to certain fruit and nut crops, the
Agency considers these applications to be non-food uses because they are
made only to non-bearing nursery stock. Thus, neither a tolerance nor an
exemption from a tolerance is required. Additionally, the Agency has
concluded that dietary exposure from consuming commodities which were
treated with A. radiobacter as nursery stock not expected.
Occupational and Residential Exposure
Based on the application methods (dipping of plants by hand and
spraying with a hand-held sprayer) listed on the product label, the potential
for eye, dermal and inhalation exposure to handlers and post application
nursery workers exists. Because of a lack of human toxicity concern, worker
exposure data are not required. Moreover, it is the Agency's opinion that these
occupational exposures and subsequent risks are negligible because: (1) the
proposed precautionary product labeling stipulated in the RED for A.
radiobacter will adequately mitigate the risks to applicators and related
nursery workers; and (2) the organism has been determined not to be
pathogenic to humans and animals.
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Human Risk Assessment
Since exposures and subsequent risks from A. radiobacter applications
are not expected, any potential risks from exposure to treated plants will be
mitigated by the use of PPE required by the WPS, supplemented by specific
precautionary labeling required by this RED. Post-application reentry
workers will be required to observe a 12-hour Restricted Entry Interval.
Because of A. radiobacter's ubiquitous nature and low toxicity, it is a
candidate for a reduced reentry interval: from 12 hours to 4 hours.
Environmental
Assessment
Additional Data
Required
Product Labeling
Changes Required
No environmental or ecological toxicity data requirements are being
required for A radiobacter in this RED, because mitigating factors support
the conclusion that exposure to non-target terrestrial and aquatic organisms is
extremely minimal. The major mitigating factor is that the registered use of
A. radiobacter being supported for reregi strati on is the treatment of certain
nursery stock in a contained environment (indoor use). Thus, little or no
exposure to the environment results from use according to label directions.
Because there is little or no exposure, the risk to non-target terrestrial and
aquatic organisms is expected to be minimal.
EPA is requiring the following information for reregi strati on A.
radiobacter: revised Confidential Statements of Formula (CSFs), and revised
product labeling.
In the evaluation of the toxicology data base for A. radiobacter, an
acute toxicity study — primary eye irritation was re-evaluated. It was
determined that the eye irritation potential is more appropriately reclassified ,
Toxicity Category III. This reduction in potential hazard prompts revision of
the precautionary labeling statements ( Signal Word — Caution vs Warning
and Statement of Practical Treatment) for end-use products. For a
comprehensive list of labeling requirements, please see the A radiobacter
RED document.
Regulatory
Conclusion
The use of currently registered products containing A radiobacter in
accordance with approved labeling will not pose unreasonable risks or adverse
effects to humans or the environment. Therefore, all uses of these products
are eligible for reregi strati on.
Agrobacterium radiobacter products will be reregistered once the
revised Confidential Statements of Formula and revised labeling are received
and accepted by EPA.
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For More
Information
EPA is requesting public comments on the Reregi strati on Eligibility
Decision (RED) document for A radiobacter during a 60-day time period, as
announced in a Notice of Availability published in the Federal Register. To
obtain a copy of the RED document or to submit written comments, please
contact the Pesticide Docket, Public Response and Program Resources
Branch, Field Operations Division (7506C), Office of Pesticide Programs
(OPP), US EPA, Washington, DC 20460, telephone 703-305-5805.
Electronic copies of the RED and this fact sheet can be downloaded
from the Pesticide Special Review and Reregi strati on Information System at
703-308-7224. They also are available on the Internet on EPA'sgopher
server, GOPHER.EPA.GOV, or using ftp on FTP.EPA.GOV, or using WWW
(World Wide Web) on WWW.EPA.GOV.
Printed copies of the RED and fact sheet can be obtained from EPA's
National Center for Environmental Publications and Information
(EPA/NCEPI), PO Box 42419, Cincinnati, OH 45242-0419, telephone 513-
489-8190, fax 513-489-8695.
Following the comment period, the A radiobacter RED document also
will be available from the National Technical Information Service (NTIS),
5285 Port Royal Road, Springfield, VA 22161, telephone 703-487-4650.
For more information about EPA's pesticide reregi strati on program, the
A. radiobacter RED, or reregi strati on of individual products containing A
radiobacter, please contact the Biopesticides and Pollution Prevention
Division (7504C), OPP, US EPA, Washington, DC 20460, telephone 703-
308-8712.
For information about the health effects of pesticides, or for assistance
in recognizing and managing pesticide poisoning symptoms, please contact
the National Pesticides Telecommunications Network (NPTN). Call toll-free
1-800-858-7378, between 8:00 am and 8:00 pm Eastern Standard Time,
Monday through Friday.
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