United States
Environmental Protection
Agency
Office of Prevention, Pesticides
And Toxic Substances
(7508W)
EPA-738-F-92-013
September 1992
R.E.D. FACTS
Pesticide
Reregistration
Use Profile
Soap Salts
All pesticides sold or used 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 Document, or RED. This fact
sheet summarizes the information in the RED for soap salts.
Soap salts include the two pesticide active ingredients potassium salts
of fatty acids (including potassium laurate, potassium myristate, potassium
oleate and potassium ricinoleate), and ammonium salts of fatty acids
(ammonium oleate).
Potassium salts of fatty acids are used as insecticides, acaricides,
herbicides and algaecides. They are used to control a variety of insects and
mosses, algae, lichens, liverworts and other weeds, in or on many food and
feed crops, ornamental flower beds, house plants, trees, shrubs, walks and
driveways, and on dogs, puppies and cats.
Ammonium salts of fatty acids are used as a rabbit and deer repellent
on forage and grain crops, on vegetables and field crops, in orchards, and
on nursery stock, ornamentals, flowers, lawns, turf, vines, shrubs and trees.
Regulatory The first pesticide product containing soap salts as an active ingredient
History was registered in 1947. Currently, 24 registered pesticide products contain
soap salts. Some of these products also contain other active ingredients.
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When EPA published reregistration List D in the Federal Register on
May 5, 1990, Soap Salts (case 4083) contained eight active ingredients.
However, four of these were combined into the single active ingredient,
potassium salts of fatty acids; three others were cancelled and are no longer
subject to reregistration. Thus, two active ingredients remain.
Potassium salts of fatty acids used on food and feed crops have been
exempted from the requirement of a tolerance (or maximum residue limit)
for all raw agricultural commodities since 1982 (please see 40 CFR
180.1068). They are generally recognized as safe (GRAS) by the Food and
Drug Administration (FDA) (please see 21 CFR 172.863). Although
ammonium salts of fatty acids also were exempted from tolerance
requirements in 1982, public notice was not provided. To correct this
oversight, EPA will publish an appropriate Federal Register notice soon.
In 1988, EPA determined that soap salts have "no independent
pesticidal activity" in antimicrobial products, and must be classified as inert
ingredients in those products (please see 40 CFR 153.139.) Therefore,
antimicrobial pesticides that contain soap salts as inert ingredients are not
subject to this RED. Antimicrobials that still contain soap salts as active
ingredients are considered misbranded and are subject to misbranding
enforcement action or cancellation.
Human Health Toxicity
Assessment Soap salts are of low toxicity when taken orally or exposed briefly to
the skin, and have been placed in Toxicity Category IV (indicating the
lowest level of toxicity) for these acute effects. However, they can cause
mild or moderate irritation when exposed to the skin for longer periods of
time. Ammonium salt products also can cause permanent eye damage.
Fatty acids normally are metabolized, forming simple compounds that
serve as energy sources and structural components used in all living cells.
However, soap salts caused reproductive and mutagenic effects when
administered to laboratory animals at high doses.
Dietary Exposure
Although people could be exposed to low levels of soap salts on foods,
these residues pose no known health risks. Soaps are mineral salts of
naturally occurring fatty acids. These fatty acids are a significant part of the
normal daily diet. Residues from the pesticide uses of soap salts are not
likely to exceed levels of naturally occurring fatty acids in commonly eaten
foods. Again, both potassium and ammonium salts of fatty acids are
exempted from tolerance requirements, and potassium salts are generally
recognized as safe by FDA.
Occupational and Residential Exposure
People applying soap salts may be exposed to these compounds.
Potassium salts are of low toxicity to humans, and there is no reason to
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expect that reasonable use will constitute any significant hazard. However,
protective eyewear is required while applying the ammonium salts of fatty
acids to prevent permanent eye injury.
Human Risk Assessment
Soap salts are of low acute toxicity when taken orally or exposed to
the skin. Residues from the pesticide uses of soap salts are not likely to
exceed levels of naturally occurring fatty acids in commonly eaten foods.
Thus, EPA believes the risks of the soap salts to applicators and consumers
are negligible. The risk of eye injury to applicators of the ammonium salts
can be mitigated by use of protective eyewear.
Environmental Environmental Fate
Assessment Hydrolysis of potassium salts of fatty acids (and probably also of
ammonium salts) does not occur over a period of 43 days. The half-life of
these fatty acids is estimated to be less than one day. As can be expected,
microbial organisms rapidly degrade fatty acids in soil. Soap salts cannot
dissipate totally in soil, however, because soil has a natural content of fatty
acids resulting from plant metabolism and microbial action. Fatty acids are
a significant part of the normal daily diet of mammals, birds and
invertebrates.
Ecological Effects
Ammonium salts of fatty acids are used outdoors as a rabbit and deer
repellent. They are practically non-toxic to upland game birds and
waterfowl. Their other potential hazards were estimated using data from the
potassium salts.
Acute and subacute toxicity studies using potassium salts of fatty acids
indicate that soap salts are relatively non-toxic to birds. They are slightly
toxic to both coldwater and warmwater fish species. The potassium salts are
highly toxic to aquatic invertebrates.
No studies regarding the effects of the soap salts on non-target insects
were available for review. Such studies still are required. In addition,
product use rate information is needed to confirm that soap salts pose a
minimal threat to endangered species.
Environmental and Ecological Risk Assessment
Pesticides containing potassium or ammonium salts of fatty acids are
used on a wide array of outdoor sites. Once applied, however, the soap
salts are degraded quickly in soil by microbes, and do not persist in the
environment. The soap salts pose minimal risks to birds and are only
slightly toxic to fish. They are highly toxic to aquatic invertebrates.
However, since soap salts are not applied directly to water, their current
uses should not seriously impact aquatic invertebrates. Additional studies
are needed to assess their effects on non-target insects. The soap salts
should pose minimal threats to endangered species. In summary, based on
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the data reviewed, EPA finds that the soap salts will not cause unreasonable
adverse effects on the environment.
Additional Data
Required
EPA has waived all generic data requirements for the soap salts except
basic product identity and chemistry studies and acute ecotoxicity studies,
which were submitted and reviewed. EPA is requiring honeybee toxicity
data for potassium salts and confirmatory ecotoxicity studies on fish and
aquatic invertebrates for ammonium salts of fatty acids to confirm that these
pesticides do not pose significant ecological hazards. Product-specific
chemistry and acute toxicology studies also are required for reregistration.
Product Labeling The labels of all registered soap salts products must comply with
Changes Required EPA's current pesticide labeling requirements. In addition,
• Products with outdoor uses and the manufacturing use product
must bear the following label statement: "This product may be
hazardous to aquatic invertebrates. Do not apply directly to water,
areas where surface water is present or to intertidal areas below the
mean high water mark. Do not contaminate water by cleaning of
equipment or disposal of water."
• Labeling of all products must include appropriate precautionary
statements.
• Labeling of ammonium salts products must require use of
protective eyewear (safety glasses, goggles or faceshield).
• Labels must upgrade the ingredients statement by declaring
potassium salts or ammonium salts of fatty acids, rather than "soap".
• Labels of products for crop uses must be upgraded by stating
specific crops and/or crop groups.
Regulatory
Conclusion
• All registered pesticide products containing the active ingredient
soap salts are not likely to cause unreasonable adverse effects in people or
the environment, and are eligible for reregistration. These products will be
reregistered once the required additional generic data, product-specific data
and revised labeling are received and accepted by EPA.
• Registered products containing soap salts as well as other active
ingredients will be reregistered once the other active ingredients also are
determined to be eligible for reregistration.
For More EPA is requesting public comments on the Reregistration Eligibility
Information Document (RED) for soap salts 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 Public
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Response and Program Resources Branch, Field Operations Division
(7506C), Office of Pesticide Programs (OPP), US EPA, Washington, DC
20460, telephone 703-305-5805.
In the future, the soap salts RED 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 soap salts or about EPA's pesticide
reregistration program, please contact the Special Review and Reregistration
Division (7508W), OPP, US EPA, Washington, DC 20460, telephone 703-
308-8000. For information about reregistration of individual soap salts
products, please contact PM Team 14, Registration Division (7505C), OPP,
US EPA, Washington, DC 20460, telephone 703-305-6600.
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, 24 hours a day, seven days a week, or fax your
inquiry to 806-743-3094.
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