United States
Environmental Protection
Agency
Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-95-016
April 1995
R.E.D. FACTS
Pesticide
Reregistration
Use Profile
Dowicil®CTAC
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 undue hazards 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 3069, Dowicil®CTAC.
Dowicil®CTAC is used as a microbicide/microbistat for secondary oil
injection water-water treatment and as a preservative for industrial adhesives
and coatings; resin/latex/polymer emulsions; metalworking cutting fluids;
oil recovery drilling muds/packer fluids; latex(in-can) paints; specialty
industrial products; textiles/textile fibers/cordage; and wet-end
additives/industrial processing chemicals.
The case Dowicil®CTAC contains the two active ingredients
Dowicil®75 and Dowicil®150. The active ingredient Dowicil®75 contains
both the cis-(«53%) and the trans- (~ 44%) isomers of l-(3-chloroallyl)-
3,5,7-triaza-l-azoniaadamantane chloride. The active ingredient
Dowicil®150 contains only the cis-isomer of l-(3-chloroallyl)-3,5,7-triaza-l-
azoniaadamantane chloride.
Regulatory
History
A pesticide product containing Dowicil®150 was first registered in the
United States in 1964 as a microbicide/microbistat. A second registration,
for Dowicil®75, was granted in 1972 for use as a preservative for paints,
latexes, metalworking lubricants, and other industrial formulations to
prevent deterioration from bacteria and fungi.
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Human Health
Assessment
The food additive use of Dowicil®CTAC to preserve adhesives, resins,
pulp, and paperboard that contact foods is regulated by the Food and Drug
Administration (please see 21 CFR Sections 175.105, 176.1680, 176.170,
and 176.180).
In 1987, EPA issued the Antimicrobial Data Call-In (DCI) Notice to
obtain chronic and subchronic toxicity data for Dowicil®CTAC and other
antimicrobials. The Agency issued a second DCI under reregistration Phase
4 in March 1992, requiring the registrant to provide chemistry, toxicology,
and environmental fate data on these active ingredients to support
reregistration.
Toxicity
In laboratory animal studies measuring acute toxicity, technical grade
Dowicil®CTAC has been shown to cause moderate effects by the dermal
route, placing it in Toxicity Category II (the second-highest of four
categories) for dermal toxicity. It has been shown to produce slight
irritation in eye and dermal irritation studies, placing it in Toxicity Category
III for eye irritation and Toxicity Category IV for skin irritation. It is
slightly toxic in oral toxicity studies, placing it in Toxicity Category III for
oral toxicity. In an acute inhalation study, Dowicil®CTAC was found to be
slightly toxic, placing it in Toxicity Category IV. This chemical is not a
skin sensitizer based on studies using guinea pigs.
A 90-day dermal toxicity study in rabbits established the NOEL for
systemic toxicity as 1000 mg/kg/day.
Dowicil®CTAC was mutagenic in the in vitro Chinese hamster ovary
cell HGPRT forward mutation assay with activation, but was nonmutagenic
without activation. It was negative in two other mutagenicity studies.
Dietary Exposure
No dietary exposure is expected from the pesticide uses of
Dowicil®CTAC since no food or feed uses are registered.
Occupational and Residential Exposure
Due to its low toxicity and the lack of a toxicological endpoint of
concern, an exposure assessment was not required for Dowicil®CTAC.
However, formaldehyde is released when Dowicil®CTAC decomposes in
aqueous solution. EPA is concerned because formaldehyde has been
classified as a Group Bl "probable human carcinogen."
The potential for exposure to Dowicil®CTAC and/or formaldehyde
exists for occupational workers involved in the industrial setting and for
individuals in the home setting. For residential uses, the Agency has
determined that potential exposure to Dowicil®CTAC is minimal. For
industrial uses, most workers' exposure to Dowicil®CTAC is low because of
current use patterns. In addition, workers in industrial settings are protected
by the Occupational Safety and Health Administration's (OSHA's)
comprehensive workplace standard for formaldehyde, with a permissible
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Environmental
Assessment
exposure level (PEL) of .75 ppm in the workplace. EPA has notified
OSHA of Dowicil®CTAC's potential to release formaldehyde and OSHA
has agreed to include these products in their workplace monitoring program.
Since Dowicil®CTAC causes moderate acute dermal toxicity (Toxicity
Category II), EPA is requiring that labels contain a statement advising
workers to wear chemical resistant gloves for open-pouring of the end-use
product.
Human Risk Assessment
Since Dowicil®CTAC has no food or feed uses, dietary risk is not
expected. The chemical causes moderate acute dermal toxicity. Therefore,
to protect applicators' skin during open pouring of end-use products, EPA is
requiring appropriate label precautions regarding use of protective clothing
(chemical resistant gloves). Although Dowicil®CTAC releases
formaldehyde in aqueous solutions, minimal risk is expected in residential
settings. Occupational risks are low due to the chemical's use pattern and
because OSHA will monitor workers' exposure to formaldehyde during
industrial uses of Dowicil®CTAC. No human health risk of concern is
therefore expected.
Environmental Fate
Dowicil®CTAC dissipates by abiotic hydrolysis. It is not persistent
and degrades rapidly under acidic conditions. Under neutral to alkaline
conditions, it degrades more slowly.
Ecological Effects
Both Dowicil®75 and Dowicil®150 are practically nontoxic to slightly
toxic to birds, fish, aquatic invertebrates, and terrestrial animals.
Ecological Effects Risk Assessment
The use patterns of Dowicil®CTAC result in minimal risk to terrestrial
organisms. Risk to nontarget aquatic organisms can be expected through
point source discharge of industrial microbicides. In the case of
Dowicil®CTAC, there are several use sites and environmental conditions
where exposure to aquatic organisms is a distinct possibility.
Based on Agency calculations using an exposure model, the chronic
level of concern (LOG) for aquatic species is exceeded in both typical and
high exposure scenarios for wet-end additives/industrial processing
chemicals and oil recovery drilling muds/packer fluids. The acute LOG is
exceeded in high exposure scenarios for all five use patterns examined.
Endangered aquatic species also are at risk under both typical and high
exposure scenarios.
It is important to note, however, that the Agency's calculations likely
overestimate the actual concentrations which would be found in the
environment. Also, discharge levels are governed by NPDES permits
granted by state regulatory agencies and EPA. Based on its rapid hydrolysis
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and use sites, no additional environmental fate date are required for
Dowicil®CTAC.
Additional Data
Required
Product Labeling
Changes
Required
Regulatory
Conclusion
For More
Information
EPA is requiring product-specific data including product chemistry
efficacy data, revised Confidential Statements of Formula (CSFs), and
revised product labeling for reregistration of products containing
Dowicil®CTAC.
The labels of all registered pesticide products containing
Dowicil®CTAC must comply with EPA's current pesticide labeling
requirements. In addition:
Effluent Discharge Statement - All end-use (and manufacturing use)
products that may be contained in an effluent discharged to the waters of the
U.S. or municipal sewer systems must bear the following statement:
"This product is toxic to fish. Do not discharge effluent containing
this product into lakes, streams, ponds, estuaries, oceans, or other
waters unless in accordance with requirements of the National
Pollutant Discharge Elimination System (NPDES) permit and the
permitting authority has been notified in writing prior to discharge.
Do not discharge effluent containing this product to sewer systems
without previously notifying the local sewage treatment plant
authority. For guidance contact your State Water Board or Regional
Office of EPA."
Handler PPE for Occupational-Use Products - The minimum
(baseline) personal protective equipment (PPE) for handlers engaged in open
pouring of Dowicil®75 and Dowicil®150 is chemical-resistant gloves.
The use of currently registered pesticide products containing
Dowicil®CTAC 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.
These Dowicil®CTAC 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 Dowicil®CTAC 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 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 Reregistration Information System at
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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
513-489-8190, fax 513-489-8695.
Following the comment period, the Dowicil®CTAC 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 reregistration program,
the Dowicil®CTAC RED, or reregistration of individual products containing
Dowicil®CTAC, please contact the Special Review and Reregistration
Division (7508W), OPP, US EPA, Washington, DC 20460, telephone
703-308-8000.
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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