United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-95-027
June 1995
R.E.D. FACTS
Pesticide
Reregistration
Ancymidol
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 reregistration, 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 3017, ancymidol.
Use Profile
Ancymidol is a plant growth regulator registered for treating
container-grown herbaceous plants, ornamental woody shrubs, and bedding
plants grown in greenhouses and other plant bedding areas for commercial
production. Growth regulator effects produced by ancymidol are the result
of inhibition of gibberellin biosynthesis. Since gibberellin promotes growth,
treatment with ancymidol induces a more compact growth form by
suppressing growth between nodes. The amount of active ingredient
required for an optimum growth response depends on pot size, stage of
growth, method of application, season, and varietal response.
Regulatory
History
Ancymidol was first registered as a pesticide in the U.S. in 1973.
In 1993 the Agency issued a Data Call4n (DCI) to the registrant for
submission of additional data on ancymidol to support reregistration.
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Human Health
Assessment
Currently there are two registered products, a technical formulation
for manufacturing-use only and an end-use product containing 0.0264%
ancymidol.
Toxicity
Testing of ancymidol for acute toxicity on animals indicates that when
inhaled, ingested, or applied to eyes, ancymidol is considered slightly
acutely toxic (Toxicity category III). When applied to skin, it is practically
non-toxic (Toxicity category IV). A subchronic 21 -day toxicity study on
rabbits showed no dermal irritation or systemic toxicity at the limit dose
(1000 mg/kg) when applied dermally. A developmental toxicity study in rats
did not indicate that ancymidol is a developmental toxicant. From that
study, a lowest observed effect level for non-developmental toxic effects
was determined to be 200 mg/kg/day, based on decreased body -weight gain
and food consumption; while the no-effect level was considered to be 50
mg/kg/day. Finally, a battery of mutagenicity studies were negative for
ancymidol. Long-term chronic toxicity testing of ancymidol has not been
conducted but is not required since it is not found in food and other potential
exposure to humans is very limited.
Dietary Exposure
No dietary exposure is expected from the pesticide uses of ancymidol
since no food or feed uses are registered.
Occupational and Residential Exposure
Since ancymidol is used as a plant growth regulator for commercial
purposes, there is potential exposure to pesticide handlers during use of the
chemical and to persons entering treated sites after application is complete.
At this time there are no products containing ancymidol intended for
residential use. Therefore, the Agency did not conduct a residential risk
assessment.
Human Risk Assessment
Since ancymidol has no food or feed uses, dietary risk is not expected.
An acute toxicity inhalation study in rats treated with ancymidol shows what
appeared to be neurotoxic effects. However, while spray applications may
produce significant exposure, concentrations of ancymidol are low in
formulated products (0.0264% a.i.), spray volatility is low, and current
usage is very small. In consideration of this, the Agency believes that the
potential risk to applicators is insignificant.
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Ecological Effects Risk Assessment
Because environmental exposure to ancymidol is very limited and low
toxicity is cited in all of the submitted studies, the Agency expects minimal
adverse effects to birds, mammals, aquatic organisms and non-target plants.
Additional Data
Required
The Agency is requiring product-specific data including product
chemistry and acute toxicity studies, revised Confidential Statements of
Formula (CSFs), and revised labeling for reregistration.
Product Labeling
Changes Required
Regulatory
Conclusion
For More
Information
end-use products containing ancymidol must comply with EPA's
current pesticide product labeling requirements. For a comprehensive list of
labeling requirements, please see the ancymidol RED document.
The use of currently registered products containing ancymidol 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 reregistration.
Ancymidol products will be reregistered once the required product-
specific data, revised Confidential Statements of Formula, and revised
labeling are received and accepted by EPA.
EPA is requesting public comments on the Reregistration Eligibility
Decision (RED) document for ancymidol 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 703^05-5805,
Electronic copies of the RED and this fact sheet can be downloaded
from the Pesticide Special Review and Reregistration Information System at
703-308^7224. They also are available on the Internet on EPA's gopher
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
513489-8190, fax 513489-8695.
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Following the comment period, the ancymidol RED document also
will be available from the National Technical Information Service (NTIS),
5285 Port Royal Road, Springfield, VA 22161, telephone 7034874650.
For more information about EPA's pesticide reregistration program,
the ancymidol RED, or reregistration of individual products containing
ancymidol, please contact the Special Review and Reregistration Division
(7508W), OPP, US EPA, Washington, DC 20460, telephone 703^08-8000.
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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