Wdsh.ngion. DC 20460
HEPA Pesticide
Fact Sheet
Name of Chemical; Bacillus subtiiis gbos
Reason for Issuance: Registration of New Biological Fungicide
Date Issued:	July 9, 1992
Fact Sheet Number: 235
Generic Name: Bacillus subtiiis GB03
Tradename: Gus 2000 Biological Fungicide
EPA Shaughnessy Code: 129068-3
Year of Initial Registration: 1992
Pesticide Type: Biological Fungicide
U.S. and Foreign Producers: Gustafson, Inc.
APPLICATION SITES: Seed treatment only. The product may be used
on all crop seeds.
METHOD OF APPLICATION: Application may be made by mixing with seed
in the planter box at the time of planting or by using standard on-
farm slurry treating equipment.
TYPE OF FORMU^TION: 2.7 5% powder formulation containing not less
than 5.5 x 10 viable Bacillus subtiiis spores/gram.
APPLICATION RATES: Application rates range from 2 to 4 ounces/100
pounds of seed.
Summary Science Statement
The results of the toxicity/pathogenicity studies submitted
indicated that the product was not toxic, pathogenic, or infective
to test animals when applied by oral, dermal, intratracheal or
intravenous methods of application. Primary eye irritation placed
the product in Toxicity category III (Caution). No reports of
hypersensitivity were reported.

Requests for waiver of requirements for testing of avian
(aquatic), aquatic organisms, non-target insect and honey bees were
granted. Non-target plant studies indicated that Bacillus
subtilis GB03 was not pathogenic to soybean seed. A request for
waiver of testing requirements for terrestrial avian species was
"denied. As a condition of registration, the registrant must submit
the results of an acute avian oral study using bobwhite quail
within one year of registration. The product will not pose a risk
to wild mammalian species.
Data for environmental fate are not triggered under current
requirements for the proposed product since the organism is a
naturally occurring species and the results of initial Tier I tests
did not trigger the need for additional testing.
Physical/Chemical Properties
Physical State:
Bulk Density:
Storage Stability:
Acute oral toxicitv/pathoaenicitv test: It was concluded from the
results of this test that the product was not toxic or infective to
rats wheji given an oral dose containing Bacillus subtilis at
1.9 x 10 colony-forming units (CFU) per animal.
Acute dermal toxicity: A single 2 gram/animal dose (3.6 x 109 CFU)
administered dermally to rabbits was not toxic. The product would
be in Toxicity category IV for dermal effects.
Acute pulmonary toxicity/pathogenicity: The product was not toxic,
pathogenic or infective to rats dosed intratracheally with
2.84 x 10 CFU of test material.
Acute intravenous toxicitv^pathogenicitv: When rats were dosed
intravenously with 1.8 x 10 CFU of test material, the product was
not infective, pathogenic or toxic to the animals.
Primary Eve Irritation: The product produced slight to severe
ocular irritation when a single 0.1 gram ocular dose was
administered which dissipated within 7 days after dosing. The
product is in Toxicity category III (Caution) for eye irritation.
Hypersensitivity: No reports of hypersensitivity were reported
from personnel working with this organism.
Musty, cheese-like
31-34 lbs/ft3
30 days

The avian acute testing requirement for Mallard duck was
waived because of natural occurrence of the organism and the lack
of aquatic exposure from a seed treatment use. Testing
requirements for other aquatic organisms were also waived for these
reasons and there are no reports of pathogenicity or toxicity of
Bacillus subtilis to aquatic species in the public literature.
Based upon lack of toxicity, pathogenicity and infectivity to
rats, the product should not pose a risk to wild mammalian species.
Studies on non-target insects and honey bees were waived because of
lack of exposure of insects to the product from seed treatment.
There have been published reports• indicating the Bacillus
subtilis may cause seed decay in soybeans so data were requested to
demonstrate the lack of pathogenicity or phytotoxicity of the
product when applied to soybean seed. Results of the tests showed
that there was no effect on the number of germinated seedlings
produced after 8 days from seed treated with the product. It was
concluded that this bacterial strain is not a seed decay organism.
A request for waiver of testing on terrestrial avian species
was requested. This waiver was denied. The registrant will be
required to submit an acute avian oral study using bobwhite quail
because of potential exposure of birds from ingesting treated
It was concluded that no risk to endangered avian (aquatic),
aquatic, plant or insect species is expected from the use of this
product because of lack of documented toxicity and little, if any,
exposure. The possibility of risk to endangered terrestrial avian
species will be evaluated upon receipt of the results from the
requested avian oral toxicity test.
The bacteria in the product, when applied to seeds, colonize
the developing root system of the plant and compete with disease
organisms which attack roots. The bacteria continue to live on the
root system and extends protection throughout the growing season.
The protection afforded by the bacteria will allow the plants to
establish a vigorous root system which generally results in a more
uniform stand and more vigorous plants. Since Bacillus subtilis is
a spore-forming bacterium, the product is more stable than other
bacterial pesticides and viability is retained even if treated seed
is stored for prolonged periods.
This biological fungicide may be an effective alternative to
chemical seed treatment fungicides and therefore could replace more
hazardous products. Because the bacteria continue protection
throughout the growing season, the need for additional post-

planting applications of chemical fungicides to control soil-borne
plant pathogens of roots may be reduced or eliminated.
An exemption from the requirement of a tolerance is proposed
to be established for the residues of Bacillus subtilis strain GB03
in or on all raw agricultural commodities when applied as a seed
treatment for growing agricultural crops in accordance with good
agricultural practices. Based upon the lack of toxicity of this
organism in the Tier 1 mammalian toxicity/pathogenicity studies, an
exemption from tolerance requirements is warranted. Also, the
organism would be destroyed by heat during cooking and would be
removed from produce by normal cleaning and washing operations
prior to consumption or processing.
The only outstanding data gap for this biological fungicide is
the requirement for conducting an acute oral toxicity/pathogenicity
study using bobwhite quail. This study is being required because
birds may be exposed to the product by ingesting treated seeds.
There have been no reports of pathogenicity of Bacillus subtilis to
avian species in the public literature, so the risk posed to
terrestrial avian species would appear to be minimal. As an added
precaution, labeling requires that spilled seed or seed exposed on
the soil surface be incorporated or covered with soil. A
conditional registration would, therefore, be justified while the
data are being developed. Protocols for the proposed testing have
been submitted and found to be acceptable.
Susan T. Lewis,
Product Manager (PM) 21,
Registration Division (H-7505C),
Environmental Protection Agency,
4 01 M Street, SW,
Washington, D.C. 20460
Office location and telephone number:
Rm. 227, CM#2,
1921 Jefferson Davis Highway,
Arlington, VA 22202.
(703) 305-1900.
DISCLAIMER: The information in this Pesticide Fact Sheet is a
summary only and is not to be used to satisfy data requirements for
pesticide registration and reregistration.