UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON D.C., 20460 

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION 

PCCode:031801,079009,079021 

DP Barcode: 425805 

March 3, 2015 

MEMORANDUM 

, SUBJECT: Revised Environmental Fate and Ecological Risk Assessment for the Registration 

Review of Soap Salts 

TO: Eric Miederhoff, Chemical Review Manager 

Patricia Parrott, Branch Chief 

Risk Management and Implementation Branch 3 

Pesticide Re-evaluation Division (7508P) 

FROM: Stephen Carey, Biologist · ')~ c:;. J )).1 

William P. Eckel, Ph.D., Seni;fs~c~ Advisor . ~ t {I / 17 ) } .--

Through: 

Environmental Risk Branch 6 -1,rV~ {! -~ ~ ti J~ Environmental Fate and Effects Division (7507P) 

Mark Corbin, Branch Chief ~ (vt S -) ~' 5 

Monica Wait, Risk Assessment Process Leader ~ w c~ ~ 13/\.5 

Environmental Risk Branch VI 

Environmental Fate and Effects Division (7507P) 

The Environmental Fate and Effects Division (EFED) has completed the revised screening level 

registration review assessment of the environmental fate and ecological risks for the soap salts 

case. This assessment addresses three active ingredients, the ammonium, potassium, and sodium 

salts of fatty acids and updates the March 5, 2013 assessment, "Environmental Fate and Ecological 

Risk Assessment for the Registration Review of Soap Salts" (Docket ID EP A-HQ-OPP-2008-

0519-0019) based on public comments received. 

1 
2 

 

Revised Environmental Fate and Ecological Risk 

Assessment for the Registration Review of Soap Salts 

Potassium Salts of Fatty Acids (PC Code 079021); 

Ammonium Salts of Fatty Acids (PC Code 031801); and 

Sodium Salts of Fatty Acids (PC Code 079009) 

 

Prepared by:

Stephen Carey, Biologist, ERB VI 

William P. Eckel, Ph.D, Senior Science Advisor, ERB VI 

U. S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch IV

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington DC 20460

Reviewed by: 

Brian Kiernan, Biologist, ERB VI 

Reuben Baris, ERB VI 

Mark Corbin, Branch Chief, ERB VI 

Date: March 3, 2015
3 

I. Executive Summary 

This risk assessment addresses the potential risks of the pesticide active ingredients potassium, 

ammonium, and sodium salts of fatty acids (“soap salts”) to the environment. It updates the 

Preliminary Risk Assessment (PRA) dated 2/28/13 based on public comments. Soap salts 

products are registered as algaecides, herbicides, insecticides/acaricides, and animal repellents. 

They are intended for residential, agricultural, or commercial use. 

Soap salts are approved by USDA for use in organic agriculture (7 CFR 205, subpart G), 

including the uses as algaecides, demossers, herbicides, insecticides, and animal repellents. 

Based on comments received during the Public comment period for the February 2013 draft risk 

assessment, the maximum broadcast application rate is now assumed not to exceed 27 lb a.i./A. 

Labeled application rates for potassium and ammonium salts of fatty acids may be as high as 205 

lb a.i./A and 104 lb a.i./A, respectively, if they were to be applied on a per acre basis However, 

based on additional use information from the registrants, the agency now recognizes that these 

higher rates are for use only applied as spot treatments that cover only a fraction of an acre. To 

be effective, soap salts generally must be applied to thoroughly wet the target pest (insect or 

plant) since they have a physical, not toxic mode of action. This limits the effect of soap salts on 

listed species to the immediate area of application. 

Sodium (and some ammonium) salts of fatty acids act as repellents on forage and grain crops, on 

vegetables and field crops, in orchards, and on nursery stock, ornamentals, flowers, lawns, turf, 

vines, shrubs and trees. Sodium salts are also formulated as a soap bar enclosed in a one-ounce 

mesh bag hung or staked above the ground, and are typically placed by homeowners in gardens, 

averaging 5 bags per garden. The per-acre application rate is thus undefined. 

These soap salts affect the olfactory nerves of deer and rabbits, repelling these animals away 

from the target area; however, ammonium salts can also be formulated as an herbicide to control 

annual weeds. FDA classifies the ammonium and sodium salts as generally recognized as safe 

(GRAS) for packaging only. Based on the use pattern, it is assumed that exposure of non-target 

organisms to these products is minimal. 

Potassium and ammonium salts are typically applied by ground equipment (hand-held, hose-end, 

foliar, pump, power, and backpack sprayers). To date, no information has been provided to 

USEPA on the geographic extent of soap salt use, but given the wide ranging use patterns, this 

assessment assumes that soap salts could be used practically anywhere in the United States. 

Potassium salts of fatty acids mainly disrupt the exoskeleton in insects, causing insects to die; 

and also disrupt the photosynthetic process in plants, killing the plant. They are used to control a 

variety of taxa including insects, mosses, algae, lichens, liverworts and other weeds. Use sites 

include many food and feed crops, ornamental flower beds, house plants, trees, shrubs, walks 

and driveways, and on dogs and cats. Some potassium salts of fatty acids are used as multipurpose food additives. The Food and Drug Administration (FDA) also classifies the potassium 

salts as GRAS (generally recognized as safe) to humans. 

In general, the soap salts do not have a toxic mode of action, and work by direct contact with the 

target pest, be it plant or insect. Thus, adverse direct effects are believed to be limited to 
4 

organisms that are present on the site of application, and at the time of application. Off-site 

effects are assumed to be unlikely because direct, intensive exposure is required for an effect to 

occur. Calculations are provided in the assessment to show that possible effects on non-target 

species extend to about 30 feet from the edge of the application area. Given the size of field 

margins, potential effects do not meaningfully extend off of cultivated areas. 

Risk Conclusions 

We conclude, based on low toxicity and limited potential for exposure, that soap salts as a group 

will not cause adverse effects to organisms that are not directly exposed. 

Soap salts are non-toxic to birds and mammals, so no adverse effects are expected. This 

conclusion is extended to their surrogates, reptiles and terrestrial-phase amphibians. 

There is very limited potential for off-site exposure in water, and we expect that the soluble 

residues to which aquatic animals and plants might be exposed are not toxic enough to cause 

adverse effects. 

Adverse effects to terrestrial invertebrates and terrestrial plants are possible, based on pesticidal 

claims and limited data. Soap salts require thorough wetting of the target pest to be effective, so 

any adverse effect to non-target organisms is believed to be limited to the site of application and 

its immediate environs. 

Uncertainties and Risk Characterization 

The product labels do not specify or limit the maximum number of applications per year or 

define a recommended minimum interval between applications. The impact of this uncertainty 

was evaluated by estimating the increase in potential exposure due to multiple applications. 

Using a screening level model (GENEEC2), the exposure increased only 3% after 50 

applications were made per year. This indicates that this label uncertainty does not substantially 

change the risk profile described above. 

An uncertainty addressed in this assessment is the relationship between the chain lengths of the 

fatty acids in the available toxicity data relative to the products used in the field. Generally, but 

not always, ammonium salts tend to be shorter-chain acids (C9 and lower), while potassium salts 

are longer-chain (C16 to C18). Also, the acute and chronic toxicological endpoints used in the 

assessment for the active ingredients were estimated based on the purity reported in their 

ecological studies using the formulated products as the test material. While the percentage of 

soap salts was specified, the composition of the chain lengths was not. Information submitted 

during the public comment period tended to confirm the identification of ammonium and 

potassium salts in the toxicity data, as being associated with short-chain and long-chain mixtures, 

respectively. It was not possible to obtain the actual endpoints for individual fatty acids from 

technical grade studies because the active ingredients are formed only after being mixed through 

an integrated process. Data for related products of known composition (the soluble fatty acid, 

nonanoic or pelargonic acid) was used to characterize the toxicity of the soap salts. Lastly, the 

composition of registered soap salt products, specifically the range of fatty acid chain lengths, is 

variable. 
5 

The composition of the product is significant due to long-chain soap salts precipitation caused by 

metal ions (Ca, Mg, Fe, etc.) in the environment. Longer chain length products should pose 

minimal risks to aquatic organisms due to this precipitation. Shorter-chain products may be 

soluble enough to cause exposure, but are not toxic enough to cause effects (i.e., acute toxicity 

data for nearly pure nonanoic (pelargonic) acid, which is representative of the shorter chainlength fatty acids, indicates that it does not reach levels of concern with a Tier I exposure 

assessment). Thus, the Agency believes there is no likely direct effect to aquatic organisms, 

because fatty acids that are high in toxicity are not sufficiently soluble in water for toxic effects 

to be expressed, and those fatty acids that are sufficiently soluble for effects to be expressed are 

low in toxicity. 

For terrestrial plants, the vegetative vigor and seedling emergence data show that soap salts are 

more toxic to plants when the foliage is exposed to spray drift, than by exposure through the 

roots as a result of surface water runoff. A commenter indicated that herbicidal soaps are 

effective only when they thoroughly contact the foliage, and are not effective by root uptake. 

Since the main route of exposure to non-target terrestrial plants is by spray drift, not by runoff, 

the LOC exceedance for potential risk to plants inhabiting dry and semi-aquatic areas exposed to 

runoff can be discounted, because the risk quotient is low compared to the level of concern (1.5 

vs. 1.0) and it does not account for degradation of the fatty acids. Spray drift exposure analysis 

indicates that when ground-based application methods are used, exposure falls to the 5% effect 

level (1.0 lb/A) for the most sensitive plants less than 30 feet off-site. This indicates that effects 

to terrestrial plants do not occur far from the site of application, and are essentially limited to the 

site of application including field margins. 

Terrestrial arthropods or invertebrates could be impacted since potassium salts are registered as 

insecticides and acaricides. Honey bee toxicity data were available, and used as a surrogate for 

terrestrial invertebrates. The data for ammonium and potassium formulations indicate that the 

highest observed mortality in bees (30%) was at a dose of 262 micrograms per bee, applied to the 

thorax. This is equivalent to an exposure of 2047 mg/kg body weight. The highest broadcast 

application rate is 27 lb/A, equivalent to 2538 mg/kg exposure to arthropods. Thus, the 27 lb/A 

rate is slightly higher than the dose causing 30% mortality. At 30 feet offsite, the exposure from 

spray drift is 1.0 lb/A or 94 mg/kg to arthropods, which corresponds to about 10 to 15% 

mortality in the laboratory tests. Thus, mortality effects to invertebrates are not expected at great 

distances from the application site, especially as label use instructions direct the user to 

thoroughly wet leaves, top and bottom, which is not likely as a result of spray drift. 

Public comments on the February 2013 preliminary risk assessment suggested that not all 

terrestrial invertebrates are susceptible to potassium salts. Susceptible invertebrates are softbodied ones such as aphids, whiteflies, and mealy bugs, including larval stages of hard-bodied 

adults. Based on the honey bee data, it appears that adult invertebrates are less susceptible. 

Toxicity was negligible in the avian and mammalian studies. Adverse effects are therefore 

unlikely to birds, mammals, and the surrogate taxa they represent (reptiles and terrestrial-phase 

amphibians). 
6 

Exposure Characterization Summary 

The fatty acid salts used in commercial pesticide products range in chain length from about C8 

(octanoic acid) to C18 (octadecanoic acid). The physical properties of these acids vary directly 

with the chain length. The chief physical property that affects exposure in this case is solubility 

in water. In the open environment, in the presence of divalent metal cations such as calcium (II), 

magnesium (II) and others, the longer fatty acids, approximately C12 and up, are too insoluble to 

reach toxic concentrations. The shorter fatty acids, approximately C11 and down, are soluble 

enough in the presence of metal ions to cause exposure in the water column, but they are not 

toxic enough to cause adverse effects. 

Effects Characterization Summary 

Aquatic Organisms

Results of the acute toxicity studies tested with soap salts formulated products indicate potassium 

salts are moderately toxic to freshwater fish, while ammonium salts are slightly toxic. Neither 

salt caused any effects to estuarine/marine fish up to the solubility limit. Ammonium salts are 

slightly toxic to freshwater invertebrates while potassium salts are highly toxic to the taxa. 

Effects of time to first brood release, reproduction, and growth were seen in freshwater 

invertebrates from chronic exposure as low as 23 mg a.i./L for ammonium salts and 0.5 mg a.i./L 

for potassium salts. Acute studies with estuarine/marine invertebrates indicate the moderately 

toxic potassium salts are more toxic than the slightly toxic ammonium salts. While no chronic 

data were available for estuarine invertebrates, potassium salts may be more toxic to 

estuarine/marine invertebrates than ammonium salts. An acute to chronic ratio was applied to 

estuarine invertebrates. For algaecide uses, aquatic nonvascular plants, algae, and diatoms 

exhibited equal inhibition of biomass when exposed to both salts. 

No toxicity data were available for sodium salts. Sodium salts are registered as a low 

volume/minor use, typically hanging bags around a home garden, which results in low potential 

for runoff and spray drift; significant concentrations are not expected to reach the receptors. 

Previously, the Agency waived all aquatic toxicity data for sodium salts. This use pattern is not 

expected to result in meaningful exposure. 

Terrestrial Organisms

Soap salts are practically non-toxic to birds and mammals on an acute exposure basis. No 

chronic toxicity data for birds and mammals were available since soap salts undergo rapid 

degradation in less than a day. Thirty percent mortality of honey bees was observed for a dose 

approximately corresponding to the maximum broadcast rate for the ammonium and potassium 

salts. 

As expected with an herbicide, effects on growth were observed in terrestrial plant studies. The 

vegetative vigor life stage is generally more sensitive than the seedling emergence life stage. 

Sensitivity varies by species, with dicots generally more sensitive to soap salts than monocots. 

No terrestrial toxicity data were available for sodium salts. 
7 

Federally Threated and Endangered (Listed) Species 

Given that the agencies are continuing to develop and work toward implementation of the 

Interim Approaches to assess the potential risks of pesticides to listed species and their 

designated critical habitat, this preliminary risk assessment for soap salts does not contain a 

complete ESA analysis that includes effects determinations for specific listed species or 

designated critical habitat. Although EPA has not yet completed effects determinations for 

specific species or habitats, for this preliminary assessment EPA conducted a screening-level 

assessment for all taxa of non-target wildlife and plants that assumes for the sake of the 

assessment that listed species and designated critical habitats may be present in the vicinity of 

the application of soap salts. This screening level assessment will allow EPA to focus its future 

evaluations on the types of species where the potential for effects exists once the scientific 

methods being developed by the agencies have been fully vetted. This screening-level risk 

assessment for soap salts indicates potential risks of direct effects to listed plants and terrestrial 

invertebrate, based on pesticidal claims, on some of the registered use sites. Listed taxa may also 

be affected through indirect effects because of the potential for direct effects on listed and nonlisted species upon which such species may rely. Potential direct effects on listed plants and 

terrestrial invertebrates from the use of soap salts may be associated with modification of 

Primary Constituent Elements (PCEs) of designated critical habitats, where such designations 

have been made. Once the agencies have fully developed and implemented the scientific 

methods necessary to complete risk assessments for endangered and threatened (listed) species 

and their designated critical habitats, these methods will be applied to subsequent analyses for 

soap salts as part of completing this registration review. 

 
8 

Contents

I. Executive Summary .............................................................................................................. 3

II. Problem Formulation ........................................................................................................... 9

II.1. Nature of the Regulatory Action ............................................................................................................. 9

II.1.1 History of Soap Salts Regulation ............................................................................................................. 9

II.2 Stressor Source and Distribution .......................................................................................................... 10

II.2.1 Nature of Chemical Stressor .............................................................................................................. 10

II.2.2. Overview of Pesticide Usage ............................................................................................................. 14

II.3 Ecosystems Potentially at Risk .............................................................................................................. 15

II.3.1 Receptors .......................................................................................................................................... 15

II.3.2. Assessment Endpoints ....................................................................................................................... 16

II.4. Conceptual Model ................................................................................................................................... 16

II.4.1. Risk Hypothesis ................................................................................................................................. 16

II.4.2. Conceptual Diagram .......................................................................................................................... 17

II.5. Analysis Plan Options ............................................................................................................................ 18

II.5.1 Measures of Exposure ....................................................................................................................... 18

II.5.2. Measures of Effect ............................................................................................................................. 19

II.5.3. Integration of Exposure and Effects .................................................................................................. 21

III. Analysis ............................................................................................................................ 23

III.1. Environmental Chemistry of Fatty Acids ................................................................................................ 23

III.2. Aquatic Exposure Modeling ................................................................................................................. 25

III.3. Ecological Effects Characterization ..................................................................................................... 29

III.3.1. Aquatic Effects Characterization ...................................................................................................... 30

III.3.2. Terrestrial Effects Characterization ................................................................................................... 33

IV. Risk Characterization ..................................................................................................... 36

IV.1. Risk Estimation ....................................................................................................................................... 36

IV.1.1 Risk Quotient Calculations for Aquatic Organisms ......................................................................... 36

IV.1.2 Risk Quotient Calculations for Aquatic Plants ................................................................................. 40

IV.1.3. Risk Quotient Calculations for Terrestrial Animals ......................................................................... 41

IV.1.4. Risk Quotient Calculations for Terrestrial Plants in Terrestrial and Semi-aquatic Environments .... 42

IV.2. Risk Description ...................................................................................................................................... 44

IV.2.1 Exposure to Aquatic Organisms ....................................................................................................... 45

IV.2.2. Exposure to Terrestrial Wildlife ....................................................................................................... 49

V. Federally Threatened and Endangered (Listed) Species Concerns ............................... 52

V.1. Action Area ............................................................................................................................................. 53

V.2. Taxonomic Groups Potentially at Risk ................................................................................................. 53

V.2.1. Probit Dose-Response Analysis ....................................................................................................... 54
9 

II. Problem Formulation 

The purpose of this problem formulation is to provide the foundation for the environmental fate 

and ecological effects for the registration review risk assessment for soap salts (Ammonium (PC 

Code: 031801), Potassium (PC Code: 079021) and Sodium (PC Code: 079009) Salts of Fatty 

Acids). Soap salts are used as insecticides, acaricides, herbicides, and algaecides on many food 

and non-food crops and are also used as a deer and rabbit repellent (ammonium and sodium salts 

only). 

II.1. Nature of the Regulatory Action 

Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), all pesticides sold or 

distributed in the United States generally must be registered by the Environmental Protection 

Agency (EPA). In determining whether a pesticide can be registered in the U.S., EPA evaluates 

its safety to non-target species based on a wide range of environmental and health effects studies. 

In 1996, FIFRA was amended by the Food Quality Protection Act (FQPA), and EPA was 

mandated to implement a new program for the periodic review of pesticides, i.e., registration 

review (http://www.epa.gov/oppsrrd1/registration_review/). The registration review program is 

intended to ensure that, as the ability to assess risk evolves and as policies and practices change, 

all registered pesticides continue to meet the statutory standard of no unreasonable adverse 

effects to human health and the environment. Changes in science, public policy, and pesticide 

use practices will occur over time. Through the registration review program, the Agency 

periodically reevaluates pesticides to make sure that as change occurs, products in the 

marketplace can be used safely. 

As part of the implementation of the Registration Review program pursuant to Section 3(g) of 

the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), the Agency is evaluating soap 

salts to determine whether they continue to meet the FIFRA standard for registration. In order to 

meet the requirements of FIFRA and the ESA, this assessment follows EPA guidance on 

conducting ecological risk assessments (USEPA 1998) and the Office of Pesticide Program’s 

Overview Document, which contains guidance for assessing pesticide risks to non-target and 

listed species (USEPA, 2004). This assessment was prepared to support evaluation of the 

registration review of soap salts. 

II.1.1 History of Soap Salts Regulation 

Soap salts were first registered as pesticides in 1947. In 1982, the Food and Drug Administration 

(FDA) classified soap salts as Generally Recognized as Safe (GRAS). A national-level 

ecological assessment was completed as part of the reregistration eligibility decision (RED) for 

soap salts in 1992 with twenty-four registered soap salts products. The ecological risk assessment 

included in the soap salts RED was based on basic laboratory fate and acute toxicity data 

submitted by the registrants in support of registration for soap salts. The primary environmental 

concern identified in the 1992 RED was associated with risks to freshwater invertebrates. The 

risks to freshwater invertebrates were not estimated using the risk quotient method at that time; 

however, the Agency assumed that the uses would not result in serious impact to freshwater 

invertebrates because soap salts are not applied directly to water and undergo very rapid 

microbial degradation in soil, from which significant concentrations should not reach water 
10 

bodies. Soap salts were reported as practically non-toxic to waterfowl and upland game birds and 

slightly toxic to both cold water and warm water fish species. 

No public literature data or incident reports were incorporated in the RED, nor were any risk 

quotients or modeled exposure concentrations used to determine if the Agency’s levels of 

concerns (LOCs) were exceeded or not. Risks were neither identified nor dismissed. No 

mitigation measures or potential risks to endangered species were assessed. The only data the 

Agency required at that time was a honeybee acute contact test to evaluate the toxicity of soap 

salts to pollinators. 

Currently, there are 44 active Section 3 products containing potassium salts of fatty acids, 8 

active products containing ammonium salts of fatty acids, and one active product of sodium salts 

of fatty acids. Fewer than ten of these are labeled for broadcast application; the soap salts 

products are primarily used for spot treatments. 

There are no pending registration actions, including emergency exemptions (Section 18) for soap 

salts. There are no currently active Special Local Need (Section 24c) registrations for soap salts. 

Twenty-two potassium salt products were subjected to reregistration, and these products have 

been reregistered or cancelled. Two ammonium salt products were subjected to reregistration and 

have been reregistered. 

 II.2 Stressor Source and Distribution 

 II.2.1 Nature of Chemical Stressor 

The soap salts case (case 4083) is comprised of three active ingredients (PC Codes 031801, 

079009 and 079021) that are the primary chemical stressors to be considered for registration 

review. These three active ingredients are: 1) potassium salts of fatty acids ([C12-C18 saturated 

and C18 unsaturated]) including potassium laurate, potassium myristate, potassium oleate and 

potassium ricinoleate combined as a single active ingredient under the PC Code formerly 

assigned to potassium laurate, PC Code: 079021; 2) ammonium salts of fatty acids ([C8-C18

saturated and C18 unsaturated]) including ammonium oleate, PC Code: 031801; and 3) sodium 

salts of fatty acids including sodium oleate, PC Code 079009. Soap salts belong to the soap 

chemical family of pesticides. There are at least 100 chemicals of this family, and they are 

generally used as insecticides, herbicides, and adjuvants. 

Potassium salts of fatty acids disrupt the membrane and cellular function in insects, causing cell 

to dehydrate and die; and also disrupt the photosynthetic process in plants, killing the plant. 

Ammonium salts of fatty acids affect the olfactory nerves of deer, rabbits, and other mammals, 

which repel these animals away from the target area, and also can be formulated as an herbicide 

to control common annual weeds. Sodium salts of fatty acids are formulated solely as a mammal 

repellent. 

Potassium and ammonium salts are typically applied by ground equipment (hand-held, hose-end, 

foliar, pump, power, and backpack sprayers). A mesh bag of sodium salts also can be hung on a 

branch or staked in the ground. Soap salts may be applied to a wide variety of use sites including 

both agricultural and non-agricultural sites. The intended use for these compounds is also varied 

with both herbicidal and insecticidal modes of action. To date, no information has been provided 
11 

on the extent of soap salt use, and given the wide ranging use patterns, it is anticipated that soap 

salts could be used practically anywhere in the United States. Of course, the non-pesticidal use 

of soap salts is widespread across the U.S. 

Potassium salts of fatty acids are used as herbicides (and algaecides) (Table II.1), insecticides 

(and acaricides) (Table II.2). They are used to control a variety of insects, mosses, algae, 

lichens, liverworts and other weeds, in or on many food and feed crops, lawn/turf, ornamental 

flower beds, house plants, trees, shrubs, greenhouses, automobiles, tires, walks and driveways, as 

a wood protection treatment, and on dogs, puppies and cats to control flea infestation. 

Table II.1. Overview on Herbicide Uses of Potassium Salts of Fatty Acids

Crop Grouping Representative Use

Terrestrial food and feed Agricultural crops/soils and vegetables 

Terrestrial food Vegetables 

Terrestrial non-food / 

greenhouse 

Agricultural crops/soils 

Greenhouse food Greenhouses-indoor use 

Greenhouse non-food Greenhouses-indoor use 

Terrestrial non-food 

Automobiles, taxis, limousines, recreational vehicles, tires, 

commercial/industrial outdoor premises/equipments, golf course turf, 

nonagricultural outdoor building/structures, recreational areas and lawns, 

commercial/industrial lawns 

Terrestrial non-food/outdoor 

residential 

Nursery stock, fencerows/hedgerows, mulch, nonagricultural rights of 

way/fencerows/hedgerows, ornamental/shade trees, ornamental herbaceous 

plants, ornamental lawns/turf, ornamental non-flowering plants, ornamental 

woody shrubs/vines, paths/patios, and paved areas of private 

driveways/sidewalks 

Outdoor residential 

Household/domestic dwellings outdoor premises, ornamental/shade trees, 

ornamental lawns/turf, residential lawns, as a wood protection treatment to 

outdoor buildings/products, paths/patios, and paved areas of private roads and 

sidewalks 

Indoor non-food Non-feed/non-food containers-full and ships/boats 

Indoor residential Household/domestic dwellings 

 
12 

Table II.2. Overview on Insecticide Uses of Potassium Salts of Fatty Acids 

Crop Grouping Representative Use

Terrestrial food and feed 

Canola/rape, peanuts, eggplant, tomato, cereal grains, seeds, apple, peas, bulb 

vegetables, wheat, field corn, sweet corn, soybeans, sugar beet, white/irish 

potato, fiber crops, cole crops, flavoring/spice crops, root and tuber vegetables, 

deciduous fruit trees, beans, vegetables and fruits, citrus, hops, nut crop/nut 

trees, pome fruits, pineapple, grapes, small fruits, fruiting vegetables, leafy 

vegetables, legume vegetables, and cotton. 

Terrestrial food 

Apple, banana, beans, blackberry, blueberry, broccoli, brussel sprouts, cabbage, 

cauliflower, citrus, coffee, cole crops, collards, cucumber, cucurbit vegetables, 

currant, eggplant, grape, kale, loganberry, melons, olive, pear, peas, pepper, 

pomegranate, potato, pumpkins, raspberry, squash (summer), squash (winter), 

squash (zucchini), strawberry, tomato, vegetables, and stone fruits. 

Terrestrial feed Alfalfa 

Terrestrial food/greenhouse 

Almond, apple, apricot, asparagus, artichoke, avocado, banana, beans, beets, 

blackberry, brassica (head and stem) vegetables, broccoli, brussel sprouts, 

cabbage, canola/rape, celery, cherry, citrus, cole crops, corn, cranberry, 

cucumber, cucurbit vegetables, deciduous fruit trees, eggplant, fig, flavoring and 

spice crops, fruiting vegetables, grapefruit, grape, herbs, hops, kale, kiwi fruits, 

leafy vegetables, legume vegetables, lemon, lettuce, lime, loganberry, 

macadamia nut, melons, nectarine, okra, orange, peach, peanuts, pear, peas, 

pecan, pepper, pineapple, plum, pome fruits, potato, radish, raspberry, root crop 

vegetables, small fruits, soybeans, spinach, squash, strawberry, stone fruits, 

subtropical fruits, tangerines, tomato, tree nuts, vegetables and fruits, watercress, 

and walnut 

Terrestrial non-food / 

greenhouse 

Ornamental/shade trees, ornamental herbaceous plants, ornamental nonflowering plants, and ornamental woody shrubs/vines 

Greenhouse food Greenhouses-indoor use, alfalfa, cotton, fruits, seeds, and wheat 

Greenhouse non-food Christmas tree plantations, ornamental/shade trees, ornamental herbaceous 

plants, ornamental non-flowering plants, and ornamental woody shrubs/vines 

Terrestrial non-food 

Citrus, pome fruits, pomegranate, stone fruits, tree nuts, tobacco, 

commercial/industrial outdoor premises/equipments, golf course turf, 

recreational areas, rose, wide area/general outdoor treatment for public health 

use, Christmas tree plantations, ornamental lawns/turf, eating establishments, 

ornamental/shade trees, ornamental woody shrubs/vines 

Terrestrial non-food/outdoor 

residential 

Ornamental/shade trees and ornamental lawns/turf 

Outdoor residential 

Fruits, household/domestic dwellings outdoor premises, ornamental/shade trees, 

ornamental herbaceous plants, ornamental lawns/turf, ornamental non-flowering 

plants, ornamental woody shrubs/vines, and residential lawns 

Indoor food Beehives/bee colony (diseased/nuisance) 

Indoor non-food 

Commercial/industrial indoor premises/equipments, ornamental/shade trees, 

ornamental herbaceous plants, ornamental non-flowering plants, ornamental 

woody shrubs/vines, and wide area/general indoor treatment 

Indoor medical Hospital/medical institutions premises 

Indoor residential 

Household/domestic dwellings, ornamental/shade trees, ornamental herbaceous 

plants, ornamental non-flowering plants, ornamental woody shrubs/vines, adult 

dogs, puppies and cats. 

Indoor residential/non-food Ornamental/shade trees, ornamental herbaceous plants, ornamental woody 

shrubs/vines, and ornamental non-flowering plants 
13 

Ammonium salts of fatty acids (Table II.3) formulated as a rabbit and deer repellent are used 

on vegetables and fruits, nursery stock, ornamentals, flowers, vines, shrubs and trees. It can 

also be formulated as a herbicide to control common annual weeds (Table II.4) actively 

growing on agricultural fields, residential gardens and paved areas, empty greenhouses, 

household dwellings, outdoor buildings, trees, plants, lawns/turf, woody shrubs/vines, and as a 

wood protection treatment to outdoor buildings/products. It is recommended not to apply any 

of the products of ammonium salts of fatty acids through any type of irrigation system. In 

addition, ammonium salt products are not compatible with soluble metallic salts such as zinc, 

manganese, and iron sulfates. This is presumably because these metal ions cause the fatty 

acids to precipitate, causing them to be ineffective.Table II.3. Overview on Repellent Uses of 

Ammonium Salts of Fatty Acids

Crop Grouping Representative Use

Terrestrial food and feed crop Apples, peanuts, and soybeans 

Terrestrial food crop Carrots (including tops), pears, and vegetables 

Outdoor residential Fruits, ornamental/shade trees, ornamental herbaceous plants, and ornamental 

woody shrubs/vines 

Terrestrial non-food Nursery stock, ornamental/shade trees, ornamental herbaceous plants, and 

ornamental woody shrubs/vines 

Table II.4. Overview on Herbicide Uses of Ammonium Salts of Fatty Acids

Crop Grouping Representative Use

Terrestrial food and feed crop Grapes, cereal grains, vegetables, orchards, field crops, mulch, grass 

forage/fodder/hay, and non-grass forage/fodder/hay 

Terrestrial food crop Ornamental lawns and turf, ornamental woody shrubs and vines, vegetables, and 

ornamental shade trees 

Greenhouse food crop Field crops and vegetables 

Outdoor residential 

Household/domestic dwellings, outdoor premises, mulch, rights-of-way, 

fencerows, hedgerows, ornamental/shade trees, ornamental herbaceous plants, 

ornamental lawns/turf, ornamental woody shrubs/vines, paths/patios, paved 

areas (private roads/sidewalks), and wood protection treatment to 

buildings/products 

Terrestrial non-food 

Empty greenhouses, outdoor building and structures, rights-of-way, fencerows, 

hedgerows, ornamental/shade trees, ornamental herbaceous plants, ornamental 

lawns/turf, ornamental woody shrubs/vines, mulch, paths/patios, paved areas 

(private driveways/sidewalks), and wood protection treatment to 

buildings/products 

Greenhouse non-food Ornamental/shade trees, ornamental herbaceous plants, and ornamental woody 

shrubs/vines 

Sodium salts of fatty acids (Table II.5) are used as a deer repellent, which are staked or hung 

next to shrubs, vines, shade trees, and ornamentals. 

 
14 

Table II.5. Overview on Repellent Uses of Sodium Salts of Fatty Acid 

Crop Grouping Representative Use

Outdoor residential Ornamental herbaceous plants, ornamental non-flowering plants, ornamental 

woody shrubs and vines, and ornamental shade trees. 

 II.2.2. Overview of Pesticide Usage 

The soap salt products may be applied at highly variable rates using broadcast ground application 

equipment and spot treatment via backpack spraying (BEAD LUIS report 05/12/13). Terrestrial 

spot treatment application rates are as high as 205 lbs/acre. The herbicidal products are generally 

applied as a spot treatment for weed control and as a broadcast spray or spot treatment for moss 

control, while the insecticidal products are applied broadcast using ground spray equipment. The 

high application rates (>27 lb a.i./A) for these products are practical only for spot treatments and 

usually are not applied to an entire acre but to thoroughly spray all plant (or tree) parts to achieve 

herbicidal or insecticidal control. Furthermore, the herbicidal products with high rates for moss 

control are labeled for lawns/turf, exterior building, and paving surfaces; not for agricultural field 

uses at rates which are about 10 times lower than used for moss control. In addition, some but 

not all labels are unclear on the number of applications allowed and do not appear to limit the 

maximum number of applications per year or define a recommended minimum interval between 

applications; however, they some labels do include restrictions such as avoiding crop-specific 

injury from repeated applications, to avoid spraying desirable plants, a buffer size or coarse 

nozzle settings to reduce spray drift to sensitive plants, or to not spray to water bodies or use in a 

manner that could cause surface water contamination. 

Based on the variable application rates described above and the inability to associate use sites 

(such as “agricultural crops” and “vegetables”) with application rates, EFED estimated the 

exposures of non-target terrestrial and aquatic animals and plants to potassium and ammonium 

salts to general “bins” of labeled application rates (1, 10, 20, and 27 lb per acre); (Table II.6). 

The dominant application types are broadcast by ground boom and backpack spray. 

Due to the difficulty in estimating exposure from backpack spraying, only broadcast applications 

will be modeled. Backpack spraying or spot treatment at non-broadcast application rates of more 

than 27 lb a.i./A will be characterized as to whether any meaningful exposure to nontargetspecies is likely. Aerial applications are not included in the assessment because they are 

unlikely to achieve the thorough foliar coverage required for effective control. 

In addition, only single applications will be modeled; the uncertainty is addressed quantitatively 

in section IV.2.1.1. 

Sodium salts uses as registered through the Agency are not applied using aircraft, ground 

equipment, or spot treatment equipment. The end-use product is unique in that it is formulated as 

a soap bar enclosed in a mesh bag that is hung or staked in an individual gardener’s backyard. 

This use pattern is not expected to result in meaningful exposure to wildlife. 
15 

Indoor premises such as greenhouse, households, industrial, commercial, and hospital are 

enclosed places where the pesticide does not reach the environment are therefore not expected to 

result in meaningful exposure to wildlife. Examples of use site groups are greenhouse food, 

greenhouse nonfood, indoor food, indoor nonfood, indoor medical, indoor residential, and indoor 

residential/nonfood uses. While potassium salts products can be used to control fleas on pets, it is 

not expected to produce concentrations as high as on agricultural fields to pose risk to the 

environment. Thus, indoor and pet uses are not included in this assessment. 

In this assessment, the term insecticidal soap refers only to those products whose active 

insecticidal ingredient is the soap itself. 

 II.3 Ecosystems Potentially at Risk 

The terrestrial ecosystems potentially at risk include the treated area, and areas immediately 

adjacent, that might receive residues of potassium and ammonium salts via drift or runoff. The 

ecosystems and communities at risk will tend to be those in close proximity to and downwind, 

downstream, or down gradient from registered use sites. For Tier 1 assessment purposes, risk 

will be assessed to terrestrial species that are assumed to feed on and otherwise occupy the 

treated area. Exposure to animals off the treated site is also possible, but exposure and risk 

estimates are likely to be lower than on the treated site. 

Aquatic ecosystems potentially at risk include water bodies adjacent to, or downstream from the 

treated field and might include impounded bodies such as ponds, lakes and reservoirs, or flowing 

waterways such as streams or rivers. For uses in coastal areas, aquatic habitat also includes 

marine ecosystems including estuaries. For Tier 1 assessment purposes, risk will be assessed to 

species in small ponds receiving runoff and drift from treated areas. 

 II.3.1 Receptors 

Potassium and Ammonium Salts 

Terrestrial receptors likely to be exposed to potassium and ammonium salts include birds, 

mammals, reptiles and terrestrial stages of amphibians that may live and forage in treated fields 

and terrestrial plants adjacent to, or down slope from treated areas. 

Table II.6. Assumptions for Potassium and Ammonium Salts 

Application Information for Exposure Analysis 

Crop Rate 

(lbs a.i./A)

No. of 

Applications Minimum Interval (days)

All Uses –Broadcast & Ground 

Application 27 1 not applicable 

All Uses –Broadcast & Ground 

Application 20 1 not applicable 

All Uses – Broadcast & Ground 

Application 10 1 not applicable 

All Uses – Broadcast & Ground 

Application 1 1 not applicable 
16 

The aquatic receptors likely to be exposed to potassium and ammonium salts include fish, 

invertebrates, aquatic stages of amphibians and plants living in waterways adjacent to or 

downstream from treated areas. 

Sodium Salts 

Based on the use pattern (suspended mesh bags), the low use rate (one ounce per bag), and the 

mode of action (mammal repellency), meaningful exposure of wildlife to the sodium salts is not 

anticipated. 

 II.3.2. Assessment Endpoints 

Assessment endpoints include reduced survival of individuals, and reproduction and growth 

impairments within populations and/or adverse effects to communities. Species potentially 

exposed include terrestrial and aquatic plants and animals. Potential effects are determined 

through testing of surrogate representatives within those taxonomic groups, or from other related 

taxonomic groups. 

In order to protect threatened and endangered species, all assessment endpoints are measured at 

the individual level. Measurement of endpoints at the individual level also provides insight 

about risks at higher levels of biological organization (e.g. populations and communities). For 

example, pesticide effects on individual survivorship have important implications for both 

population growth increase and habitat carrying capacity. 

Assessment endpoints and toxicity data used for the risk assessment are identified in Table II.7. 

 II.4. Conceptual Model 

In order for a chemical to pose an ecological risk, it must reach ecological receptors in 

biologically significant concentrations. An exposure pathway is the means by which a pesticide 

moves in the environment from a source to an ecological receptor. For an ecological exposure 

pathway to be complete, it must have a source, a release mechanism, an environmental transport 

medium, a point of exposure for ecological receptors, and a feasible route of exposure. 

The conceptual model depicts the potential pathways for ecological risk associated with soap 

salts use. The conceptual model provides an overview of the expected exposure routes for 

animals and plants within the soap salts action area. 

 II.4.1. Risk Hypothesis 

Risk hypotheses are specific assumptions about potential adverse effects (i.e. changes in 

assessment endpoints) and may be based on theory and logic, empirical data, mathematical 

models, or probability models (EPA, 1998). For this assessment, the risk is stressor-linked, 

where the stressor is the release of soap salts to the environment. The following risk hypothesis 

was developed for this registration review. 

The use of soap salts as herbicides, insecticides, acaricides, algaecides, and repellents in 

outdoor and terrestrial crop and non-crop sites will likely cause exposure of terrestrial and 

aquatic animals and plants. Based on the mobility and persistence of soap salts, the mode of 
17 

action, and the food-web of the target aquatic and terrestrial ecosystems, soap salts have the 

potential to cause reduced survival, and reproductive and growth impairment for both terrestrial 

and aquatic animals and plant species. 

 II.4.2. Conceptual Diagram 

The potential exposure pathways and effects of the registered uses of potassium and ammonium 

salts on crops and non-crops are depicted in Figure 1. Solid arrows depict the most likely routes 

of exposure and effects; dashed lines depict potential routes of exposure that are not considered 

likely for soap salts. 

Application of Potassium and Ammonium Salts to Food and Feed Crops, Ornamental Flower Beds, House Plants, Trees, Lawn, 

Stressor Shrubs, Walks and Driveways, on Dogs, Puppies and Cat, and as a Rabbit and Deer Repellent

Direct Ground Deposition

Volatilization/

Wind Suspension Leaching

Non-Target Plants:

•Plant growth abnormalities

•Lethality

•Developmental/reproductive

effects

Source:

Transport Pathway

Terrestrial Animals:

•Lethality

•Reproductive/developmental

effects

Aquatic Animals and Plants:

•Effects to survival, growth, and 

reproduction

•Reductions in cell density/ 

biomass in aquatic plants

Altered Terrestrial Community Assemblages:

Reduced food supply and edge habitat availability

Altered Aquatic Community Assemblages:

Effects to riparian habitat availability

Effects to species abundance/diversity

Changes in physical/chemical parameters

Source:

Exposure Media

Exposure Point

Receptors

Direct Effects

Indirect Effects

Terrestrial Food Residues

(foliage, fruit, insects)

Direct Contact

& Ingestion

Terrestrial

Vertebrates and 

Invertebrates

Direct Contact/

Root Uptake

Terrestrial

Upland

Plants

Surface Water

Sediment Groundwater

Gill/Integument

Uptake

Aquatic

Invert &

Vertebrates

Upland Soil and 

Foliage

Riparian/Wetland

Foliage/Soil

Spray

Drift Runoff/

Erosion

Uptake/

Adsorption

Riparian/

Wetland

Plants

Aquatic

Plants

Plant Population

Reduced Population

growth

Figure 1 - Conceptual Model Diagram: Potassium and Ammonium Salts Application to Terrestrial 
18 

Habitats 

 II.5. Analysis Plan Options 

In order to address the risk hypothesis in the soap salts registration review, the potential for 

adverse effects on non-target aquatic and terrestrial animals and plants will be analyzed in 

accordance with the Agency’s Overview Document (Overview of the Ecological Risk 

Assessment Process in the Office of Pesticide Programs, U.S. Environmental Protection Agency, 

January 2004). 

During this step, measurements of effect and exposure used to evaluate the risk hypothesis are 

delineated. The Analysis Plan provides a synopsis of measures that will be used to evaluate the 

risk hypothesis for soap salts. There are three categories of measures: exposure, effects, and risk. 

 II.5.1 Measures of Exposure 

The measures of exposure are estimated using standard EFED models. Aquatic exposure 

consists of aquatic estimated environmental concentrations (EECs) derived using a waterbody 

that is vulnerable and representative of static ponds and first order waterways. Because only the 

shorter-chain fatty acids are soluble in environmental water, aquatic exposures will be modeled 

as nonanoic (pelargonic) acid, a representative soluble fatty acid. 

Terrestrial exposures are estimated using a model that assumes direct application to a variety of 

avian, mammalian and reptilian food items. Exposure to terrestrial plants are estimated using a 

model that assumes potassium and ammonium salts drift or move with runoff to adjacent 

habitats. 

The only potential exposure of the sodium salts mesh bags to the environment would be via 

direct ingestion of the mesh bags (e.g., there would be minimal surface water runoff, spray drift, 

or residues expected on potential food items). Direct ingestion is considered to be highly 

unlikely. 

Aquatic Animals and Plants 

Tier I simulation model GENEEC2 was used to generate estimated environmental concentrations 

(EECs) that may occur in surface water bodies adjacent to application sites. The predicted peak, 

21-day, and 60-day concentrations are used to estimate risk to aquatic animals and plants 

inhabiting shallow-water aquatic communities that receive runoff during rainfall events and/or 

drift from adjacent use sites. More details on GENEEC2 may be found at the following website: 

http://www.epa.gov/oppefed1/models/water/index.htm#geneec2

Aquatic Exposure Monitoring and Field Data 

No monitoring data are available for soap salts. Even if monitoring data were available, it is 

unlikely that exposures from pesticidal and non-pesticidal uses could be distinguished. 
19 

Terrestrial Animals 

The potential exposure pathways for terrestrial plants and animals include spray drift deposition 

from ground spray applications, runoff/leaching from treated areas, direct consumption of mesh 

bags (considered unlikely), resulting in residues on non-target species as well as residues on food 

items for non-target species. EFED uses the T-REX and TERRPLANT models to estimate 

exposure concentrations of potassium and ammonium salts to non-target terrestrial animals and 

plants, respectively, following single broadcast application rates of 1.0, 10, 20, and 27 lb a.i./A. 

Because soap salts were found to be non-toxic to birds and mammals, no TREX exposure 

assessment is presented. Possible risk to birds and mammals, and their surrogates reptiles and 

terrestrial-phase amphibians, will be considered qualitatively in the risk characterization. 

Terrestrial Plants 

TerrPlant (v. 1.2.2) was developed to provide screening level estimates of exposure to terrestrial 

plants from single pesticide applications. The model does not consider exposures to plants from 

multiple pesticide applications. TerrPlant derives pesticide EECs in runoff and in spray drift. 

Based on public comments, adverse effects are considered more likely via the spray drift route. 

RQs are developed for non-listed and listed species of monocots and dicots inhabiting dry and 

semi-aquatic areas that are adjacent to treatment sites receiving runoff and/or drift from 

applications on sites treated with potassium and ammonium salts. 

In addition, the AgDRIFT spray drift model (v. 2.01) will be used to assess exposures of 

terrestrial plants to potassium and ammonium salts deposited on terrestrial habitats by spray drift. 

The model consider the amount deposited on a given distance by spray drift to assess the 

distance (feet) from the edge of field a deposition needs to fall below the terrestrial plant LOC. 

Drinking water and inhalation risks are not quantitatively examined in this assessment, due to the 

non-toxicity of soap salts to birds and mammals. 

 II.5.2. Measures of Effect 

Measures of ecological effects are obtained from submitted guideline studies conducted with a 

limited number of surrogate species on soap salts. The test species are not intended to be 

representative of the most sensitive species but rather were selected based on their ability to 

thrive under laboratory conditions and their standardized use for toxicity studies of a variety of 

chemicals. Toxicity testing does not represent all species of birds, mammals, or aquatic animals. 

Only a few surrogate species for both freshwater fish and birds are used to represent all 

freshwater fish (2000+) and bird (680+) species in the United States. For mammals, acute 

studies are usually limited to the laboratory rat. Estuarine/marine testing is usually limited to a 

crustacean, a mollusk, and a fish. In addition, neither reptiles nor amphibian data are available. 

The risk assessment assumes that avian, terrestrial-phase amphibian and reptilian toxicities are 

similar. The same assumption is used for fish and aquatic-phase amphibians. 
20 

As noted previously, the correspondence between the products tested in the toxicity studies, and 

particular currently registered products, is uncertain. The uncertainty is mainly due to 

unspecified fatty acid chain length compositions. Exposure modeling was therefore also 

conducted on a surrogate substance (C9 fatty acid or nonanoic acid) that comprises the bulk of 

the fatty acid content in products expected to be soluble in environmental waters. 

Where available, sublethal effects observed in acceptable studies will be evaluated qualitatively. 

Such effects may include behavioral changes (e.g., lethargy and changes in coloration). 

Quantitative assessments of risks, though, are limited to those endpoints that can be directly 

linked to the Agency’s assessment points of impaired survival, growth and reproduction. 

The following table (Table II.7) lists the measures of environmental exposure and ecological 

effects used to assess the potential risks of potassium and ammonium salts of fatty acids to nontarget organisms. The methods used to assess the risk are consistent with those outlined in the 

document “Overview of the Ecological Risk Assessment Process in the Office of Pesticide 

Programs” (USEPA, 2004). 
21 

Table II.7. Measures of Exposure and Measures of Effect Used in Assessing Potential Risks. 

Assessment Endpoint Surrogate Species and Measures of 

Ecological Effect1 

Measures of Exposure 

Birds2

Survival Lowest acute LD50 (single oral dose test) 

and LC50 (subacute dietary test)

Upper-bound residues on 

food items and estimates 

on concentration of the 

mesh bag for consumption 

(animal repellent use). 

Reproduction 

and Growth 

Lowest NOAEC 

(21-week reproduction test) 

Mammals 

Survival Lowest acute LD50 (single oral dose test)

Reproduction 

and Growth 

Lowest NOAEC 

(2-generation reproduction test) 

Aquatic Animals (Fish 

and invertebrates)3 

Survival Lowest tested LC50 or EC50

(acute toxicity test) Peak EECs4 

Reproduction 

and Growth 

Lowest NOAEC (early life-stage or full 

life-cycle tests) 

21-day EECs for 

invertebrates and 60-day 

EECs for fish4 

Terrestrial plants5 Survival and 

growth 

Lowest EC25 (for non-listed plants) and 

corresponding NOAEC (for listed plants) 

(endpoints derived for monocots and 

dicots from seedling emergence and 

vegetative vigor studies) 

Estimates of runoff and 

spray drift to non-target 

areas 

Insects6 Survival (not 

quantitatively 

assessed) 

Lowest honeybee LD50 (acute contact 

test) 

Maximum application rate 

for honeybees 

Aquatic plants (vascular 

and non-vascular) 

Survival and 

growth 

Lowest EC50 (for non-listed plants) and 

corresponding NOAEC or EC05 (for 

listed plants)

Peak EECs4

1 The most sensitive species tested within taxonomic groups is used for screening-level risk assessments. 2 Birds represent surrogates for terrestrial-phase amphibians and reptiles. 

3 Freshwater fish represent surrogates for aquatic-phase amphibians. 4 Aquatic EECs are based on modeling described in Section III. 5 Four species of two families of monocots - one is corn, six species of at least four dicot families, of which one is soybeans. 6

 Risk to terrestrial invertebrates from use is not evaluated, rather the potential hazard to honey bees (i.e. the available data) 

are qualitatively assessed.

 II.5.3. Integration of Exposure and Effects 

Risk characterization is the integration of exposure and ecological effects to determine the 

potential ecological risk from the use of soap salts of fatty acids and the likelihood of direct and 

indirect effects to non-target animals and plants in aquatic and terrestrial habitats. The exposure 

and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects 

on non-target species. For the assessment of risks from exposure to potassium and ammonium 

salts, the risk quotient (RQ) method is used to compare exposure and measured toxicity values. 

EECs are divided by acute and chronic toxicity values. The resulting RQs are then compared to 

the Agency’s Levels of Concern (LOCs) (USEPA 2004) (Table II.8). The chance of an 

individual effect (mortality) can be calculated for the RQ using the Individual Effects Calculator 

(IEC). These criteria are used to indicate when soap salts’ uses, as directed on the label, have the 

potential to cause adverse direct or indirect effects to non-target animals and plants. 
22 

Table II.8. Agency Risk Quotient (RQ) Metrics and Levels of Concern (LOC) Per Risk 

Class 

RISK CLASS RISK DESCRIPTION RQ LOC 

Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non-listed animals from acute 

exposures 

Peak EEC/LC501

 0.5 

Acute 

Restricted Use 

Potential for effects to animals from acute exposures 

Risks may be mitigated through restricted use classification Peak EEC/LC501

 0.1 

Acute Listed 

Species 

Listed species may be potentially affected by acute 

exposures 

Peak EEC/LC501

 0.05 

Chronic Potential for effects to non-listed and listed animals from 

chronic exposures 

60-day EEC/NOAEC 

(fish) 1 

21-day EEC/NOAEC 

(invertebrates) 

Aquatic Plants 

Non-Listed Potential for effects to non-listed plants from exposures Peak EEC/LC501 1 

Listed Potential for effects to listed plants from exposures Peak EEC/NOAEC 1 

Terrestrial Animals (mammals and birds) 

Acute Potential for effects to non-listed animals from acute 

exposures 

EEC2

/LC50 (Dietary) 0.5 

EEC/LD50 (Dose) 

Acute 

Restricted Use 

Potential for effects to animals from acute exposures 

Risks may be mitigated through restricted use classification

EEC2

/LC50 (Dietary) 0.2 

EEC/LD50 (Dose) 

Acute Listed 

Species 

Listed species may be potentially affected by acute 

exposures 

EEC2

/LC50 (Dietary) 0.1 

EEC/LD50 (Dose) 

Chronic Potential for effects to non-listed and listed animals from 

chronic exposures EEC/NOAEC 1 

Terrestrial and Semi-Aquatic Plants 

Non-Listed Potential for effects to non-target, non-listed plants from 

exposures 

EEC/ EC25 1 

Listed Plant Potential for effects to non-target, listed plants from 

exposures 

EEC/ NOAEC 

1 

EEC/ EC05

1 LC50 or EC50. 2

 Based on upper bound on feed items 
23 

III. Analysis 

III.1. Environmental Chemistry of Fatty Acids 

The sodium, potassium and ammonium salts of fatty acids across the range C8 to C18 are 

“soluble” in water, meaning at the maximum completely miscible. The corresponding free acids 

are less soluble (C8, 789 mg/L and C18, 0.6 mg/L). Thus, formulating the Soap Salt products as 

sodium, potassium, or ammonium salts aids in the solubilization of the fatty acid moieties in 

water. 

The solubility of fatty acid salts of divalent metal cations (Ca2+, Mg2+, Zn2+) is much lower than 

that of the sodium, potassium, and ammonium salts. This is why “ammonium salt products are 

not compatible with soluble metallic salts such as zinc, manganese, and iron sulfates.” The metal 

ions precipitate the fatty acids as insoluble, high molecular weight salts and make them 

biologically unavailable. In “hard” water, which is high in Ca and Mg, this is observed as “soap 

scum” on bathtubs and sinks. The metal ion content of soil provides repeated opportunity for 

fatty acids to be precipitated out of run-off before reaching an exposure point. 

Irani and Callis (1960) reported good correlation between solubility and the number of carbons 

in saturated fatty acid calcium salts according to the following equations: 

-logKsp = -2.63 + 1.24C 

Ksp = [Ca2+][fatty acid]2 

where Ksp is the solubility product constant of the salt and C is the number of carbon atoms in 

the chain. Taking 0.3 mmolar (12 mg/L) as [Ca] for soft water, and 3 mmolar (120 mg/L) as 

[Ca] for hard water, Table III.1 gives the solubility limit in mg/L of saturated fatty acid calcium 

salts, as [fatty acid] in soft and hard water, along with laboratory-measured solubility data given 

in EPISuite for unknown water hardness conditions. 

___________________________________________________________________________ 

Table III.1. Solubility Limits of Calcium Fatty acid salts, as mg/L [fatty acid] 

Carbon# 

MW 

acid logKsp Ksp(1) 

Soft 

 water(2) 

Hard 

water(3) 

Acid 

solubility 

(4) 

8 144.22 7.29 5.13E‐08 1886 596 789

9 158.24 8.53 2.95E‐09 496 157 284

10 172.27 9.77 1.699E‐10 130 41 61.8

11 186.3 11.01 9.77E‐12 34 11 52

12 200.32 12.25 5.623‐13 8.7 2.7 4.8

13 214.35 13.49 3.24E‐14 2.2 0.70 33

14 228.38 14.73 1.86‐15 0.57 0.18 1.07

15 242.41 15.97 1.07E‐16 0.14 0.046

16 256.43 17.21 6.17E‐18 0.037 0.012 0.04

17 270.46 18.45 3.55E‐19 0.0093 0.0029

18 284.49 19.69 2.04E‐20 0.0023 0.00074 0.597

(1) solubility product constant. (2) fatty acid solubility in soft water. (3) fatty acid solubility in hard water. (4) laboratory-
24 

measured solubility literature values from EPISuite in water of unknown hardness. 

The lowest toxicity endpoint for potassium and ammonium soap salts (Tables III.9 and III.10) 

is higher (0.39 mg/L for algae NOAEC) than the solubilities for C15 and above, indicating that 

fatty acids above C15 are too insoluble to reach toxicity thresholds. Thus the fatty acids 

contributing to the exposure are generally the more soluble C8 to C12 acids. 

Data for dodecanoic acid (MRID 43465501) indicate that its calcium salt is not soluble enough 

to reach the measured LC50 for fish (36 mg/L), and that the EC50 for Daphnids (16.9 mg/L) is 

over the solubility limit (8.7 mg/L in soft water and 2.7 mg/L in hard water). Above C12, the 

fatty acids may be too insoluble in environmental water to reach these acute toxicity thresholds. 

The environmental fate models used by OPP to estimate fatty acid concentrations in water do not 

account for interaction with metal ions. Thus, it can be expected that fatty acid concentrations 

will be lower in waters with relatively high metal ion content than the models predict. Also, in 

some agricultural situations, lime, which is rich in Ca, is added to raise the pH of the soil. The 

presence of added Ca in agricultural fields should also serve to limit the solubility and mobility, 

and thus the environmental water concentration, of fatty acids. 

Environmental Fate Summary 

A typical commercial soap is made by saponification of fats with a strong base to produce a salt 

of a fatty acid (C12 –C18 saturated). These fatty acids in soap are an excellent energy source in 

soil and are among the most efficient energy sources available to living cells. Fatty acids 

constitute a significant portion of the normal daily diet of mammals (including humans), birds, 

and invertebrates since they are found in large amounts in the form of lipids in all living tissues 

(including seeds). 

Hydrolysis of potassium salts of fatty acids did not occur over a period of 43 days (MRID 

470307006). This is consistent with open literature data on fatty acids, which indicates that the 

primary environmental degradation route of fatty acids is by micro-floral action (the cleavage of 

the carbon chain of fatty acids requires oxidative chemistry) as opposed to hydrolysis. 

Aqueous photolysis of two formulated products of fatty acids (Safer’s Weed and Grass Killer 

Concentrate and Safer’s Sapestain) was tested (MRID 470307007). The active ingredient in this 

study was free fatty acids which showed no degradation during the 32 day course of the study. 

Due to the similarity of chemical structure, it is expected that hydrolysis of the ammonium salts 

of fatty acid would be similar to that of the potassium salts of fatty acids. 

An aerobic soil metabolism study (MRID 470168026) submitted to the Agency indicated that the 

half-life of these fatty acids is less than one day. The study was conducted using soil collected 

below turf, and analytical results were reported over a three week period. Both sterilized and 

non-sterilized soils were treated and the results indicate that the natural fatty acid content of the 

soil was lower than the fatty acid content of the treated soil. The results also indicated that the 

concentration of fatty acids in the treated soils had declined to natural levels within 10 days of 

treatment and that the primary mechanism of degradation was via microbial processes. 

Extraction for individual degradates was not done because microbial metabolism of fatty acids 
25 

has the effect of either converting the degradates to CO2, or converting the carbon content of the 

fatty acid to any of the thousands of naturally occurring organic substances produced by the soil 

micro flora (if used as a carbon source). 

Finally, an adsorption/desorption study (MRID 470306008) was submitted for two fatty acids 

including Capric and Pelargonic fatty acids. The study suggests that leaching of Capric and 

Pelargonic fatty acids would be minimal, although no Kd or Koc estimates were provided nor 

could they be calculated using the data provided in the study. 

In order to address the need for adsorption data (either Kd or Koc) for modeling purposes EFED 

estimated Koc values for a variety of fatty acids using EpiSuite. EpiSuite is modeling software 

that relies on a database of physical/chemical property data and a suite of environmental fate 

estimation models developed by EPA’s Office of Pollution Prevention & Toxics (OPPTS). 

Estimates of Koc were generated for nonanoic acid, because this fatty acid represents an average 

chain length for soap salt products that are soluble enough in environmental water to cause 

exposure. Estimates of Koc for nonanoic acid ranged from 53 mL/g (molecular connectivity 

index method) to 111 mL/g (Kow method). A value of 100 mL/g was taken to be representative 

of soap salt mixtures of length C8 to C11. 

http://www.epa.gov/opptintr/exposure/pubs/episuite.htm

In addition, EPA’s OPPTS maintains a database of physical/chemical property data under the 

High Production Volume (HPV) Challenge Program. The HPV program makes human health 

and environmental effects data available to the public and includes information on Tall Oil Fatty 

Acids and Related Substances. This database includes limited information on these fatty acids 

but does include several compounds specifically included in this assessment including potassium 

salts of fatty acids, fatty acids, tall oil, and sodium salts of fatty acids. The environmental fate 

data set for these fatty acids is limited but does include some information on log Kow and 

persistence as measured by biodegradation. In general, these data are consistent with the 

environmental fate data summarized above and suggests that these fatty acids have the potential 

to bioaccumulate but are not likely to be persistent. More information on the HPV program in 

general and the specific data for tall oils may be found at the following website: 

http://www.epa.gov/hpvis/ 

III.2. Aquatic Exposure Modeling 

Because the longer-chain fatty acids present in soap salts are not expected to be soluble enough 

for toxicity to be expressed, the exposure modeling needs to be based on the short-chain acids 

(generally C8 to C12). It was therefore assumed that only the portion of the product up to C12 

contributes to the exposure. Maximum broadcast application rates (27 lb/acre) were used. 

Maximum spot treatment rates with higher application rates than the broadcast application rates 

were not modeled. Because the maximum broadcast rates include an insoluble portion, modeling 

the exposure as only soluble fatty acid overstates the actual exposure. For this range (C8 to 

C12), an overall solubility of 100 mg/L, limited by metal ion concentrations, was judged to be 

representative based on the data in Table III.1. This is roughly equivalent to the solubility of 

C10 acid in soft water (130 mg/L). 
26 

Model input parameters (Table III.2) were selected based on laboratory fate data in accordance 

with EFED’s input parameter guidance. More information on selection of input parameters for 

GENEEC2 may be found at the following website: 

http://www.epa.gov/oppefed1/models/water/input_guidance2_28_02.htm

Table III.2. GENEEC2 Input Parameters for Soap Salts for Aquatic Ecological Exposure Assessment 

for Broadcast Applications

Model Parameter Value Comments Source

Spray Drift by Scenario ground -6.6 % Default Assumption 1 

Aerobic Soil 

Metabolism (t 1⁄2) 1 day MRID 470168026 

Aerobic Aquatic 

Degradation (t 1⁄2) 2 days 

2x aerobic soil 

metabolism value due to 

lack of data 1 

Aqueous Photolysis 

(t 1⁄2) Stable MRID 470304007 

Hydrolysis Stable MRID 470307006 

Koc 100

Estimates are 

representative of mixtures 

dominated by nonanoic 

acid (C9) 

EpiSuite Estimates 

Water Solubility 100 mg/l EpiSuite Estimates 

1- From “Guidance for Chemistry and Management Practice Input Parameters for Use in Modeling the Environmental Fate and 

Transport of Pesticides” 

Modeling Results 

Aquatic EECs calculations generated from GENEEC2 for the registered uses of soap salts on 

outdoor sites based on maximum broadcast application rates have been updated for risk 

estimations in this screening-level assessment (Table III.3). The highest broadcast application 

rate for potassium and ammonium salts (27 lb a.i./A) coupled with the representative Koc for 

lower chain length products (100) yield the EECs in Table III.3. Broadcast application rates for 

modeling purposes were selected in accordance with a range of broadcast application rates (i.e., 

1, 10, 20 and 27 lb a.i./A) in order to assess the relative magnitude of exposure across the 

spectrum of use sites and application rates allowed. EECs for spot treatment applications are not 

available; however, exposure from spot treatment using backpack sprayers will be subsequently 

discussed for any potential risks to non-target wildlife and plants after the assessment on 

broadcast applications. 
27 

Table III.3. Exposure Estimates (ppm) for Soap Salts modeled as 

Nonanoic Acid 

Application Rate 

 lb a.i./A

Peak 21-Day Avg 60-Day Avg

Ground Application 

27 0.378 0.1 0.0378 

20 0.28 0.076 0.028 

10 0.14 0.038 0.014 

1 0.014 0.0038 0.0014 

Terrestrial Organisms 

Exposure modeling for birds and mammals, and by extension, reptiles and terrestrial phase 

amphibians, was not conducted because soap salts are non-toxic to these taxa. The risks to these 

taxa is considered qualitatively in the Risk Characterization. 

Terrestrial Plants 

Modeling Results 

EFED's exposure scenario for off-site plants is based on the broadcast application rates (spot 

treatment application rates are excluded), application method (ground), and the water solubility 

of the pesticide. The amount of pesticide that runs off is a proportion of the application rate and 

is assumed to be 1%, 2%, or 5% for water solubility values of <10 mg/L, 10-100 mg/L, and >100 

mg/L, respectively. For soap salts, a runoff value of 2% is presumed, based on the solubility of 

100 mg/L in water, representing C9 fatty acid. Drift from ground-spray applications are assumed 

to be 1% of the application rate. The EECs are tabulated below in Table III.4. Further 

refinement of the exposures to plant from off-site drift using the AgDRIFT model are discussed 

in Section IV.2.2.4.

Table III.4. TERRPLANT EECs for Terrestrial Plants Located Adjacent to Potassium 

and Ammonium Salts Treated Sites. 

Broadcast 

Application 

Rate 

(lb a.i./A) 

Application 

Method 

 TERRPLANT EECs (lbs a.i./A) 

Total Loading to 

Areas Adjacent 

to Treated 

Areas1

Total Loading to 

Semi-Aquatic Areas 

Adjacent to Treated 

Areas2

Drift to 

Adjacent 

Areas3

27 

Ground 

Unincorp. 

Spray 

0.81 5.67 0.27 

20 0.6 4.2 0.2 

10 0.3 2.1 0.1 
28 

Table III.4. TERRPLANT EECs for Terrestrial Plants Located Adjacent to Potassium 

and Ammonium Salts Treated Sites. 

Broadcast 

Application 

Rate 

(lb a.i./A) 

Application 

Method 

 TERRPLANT EECs (lbs a.i./A) 

Total Loading to 

Areas Adjacent 

to Treated 

Areas1

Total Loading to 

Semi-Aquatic Areas 

Adjacent to Treated 

Areas2

Drift to 

Adjacent 

Areas3

1.00 0.03 0.21 0.01 

1 EEC = Sheet Runoff + Drift (1% for ground) 

2

 EEC = Channelized Runoff + Drift (1% for ground) 

3 EEC for ground (appl. rate x 1% drift)
29 

 III.3. Ecological Effects Characterization 

In screening-level ecological risk assessments, effects characterization describes the types of 

effects a pesticide can have on aquatic and terrestrial organisms. This characterization is based 

on the registrant-submitted toxicity data for birds, mammals, fish, invertebrates, and plants for 

the soap salts registration review. Effect data were available for potassium and ammonium salts; 

however, none were available for sodium salts. With sodium salts registered as a low 

volume/minor use and the only potential exposure to the environment is via direct ingestion of 

the bar (e.g. there would be no runoff, spray drift, or residues expected on potential food items), 

toxicity data were waived. 

As described in the Agency’s Overview Document (USEPA 2004), the most sensitive endpoint 

for each taxon is used for risk estimation. For this assessment, evaluated taxa include freshwater 

fish, freshwater invertebrates, aquatic plants, birds (also surrogate for terrestrial-phase 

amphibians and reptiles), terrestrial invertebrates, and terrestrial plants. Mammalian endpoints 

were not available for risk estimation as the Agency’s Health Effects Division (HED) has waived 

all mammalian endpoints due to available data for related products of known composition that 

show lack of effects at high rates to mammals. 

Toxicity endpoints are established based on data generated from guideline studies submitted by 

the registrant, and from open literature studies that meet the criteria for inclusion into the 

ECOTOX database maintained by EPA/Office of Research and Development (ORD) (U.S. EPA, 

2004). Open literature data searched for this screening assessment were obtained from 

ECOTOX information obtained in June 2008. In order to be included in the ECOTOX database, 

papers must meet the following minimum criteria: 

(1) the toxic effects are related to single chemical exposure; 

(2) the toxic effects are on an aquatic or terrestrial plant or animal species; 

(3) there is a biological effect on live, whole organisms; 

(4) a concurrent environmental chemical concentration/dose or application rate is 

reported; and 

(5) there is an explicit duration of exposure. 

Data that pass the ECOTOX screen are evaluated along with the registrant-submitted data, and 

may be incorporated qualitatively or quantitatively into this assessment. In general, effects data 

in the open literature that indicates effects at lower concentrations than the registrant-submitted 

data are considered. The degree to which open literature data are quantitatively or qualitatively 

characterized is dependent on whether the information is relevant to the assessment endpoints 

(survival, reproduction, and growth) identified in Section II.5. For example, endpoints such as 

behavior modifications are likely to be qualitatively evaluated, because quantitative relationships 

between modifications and reduction in species survival, reproduction, and/or growth are not 

available. To date, none of the open literature that passed the ECOTOX screen resulted in effects 

at lower concentrations than the registrant submitted studies and thus are not used in this risk 

assessment. 

Ecological effects studies are typically performed using the technical grade active ingredient 

(TGAI); however, because the soap salts are formed through an integrated manufacturing 
30 

process, there is no technical product. To resolve these issues, the Agency requested studies with 

the formulated products. 

In addition to registrant-submitted and open literature toxicity information, other sources of 

information, including use of the acute probit dose-response relationship to establish the 

probability of an individual effect and reviews of the Ecological Incident Information System 

(EIIS), are conducted to further refine the characterization of potential ecological effects 

associated with exposure to soap salts. A summary of the available aquatic and terrestrial 

ecotoxicity information and use of the probit dose-response relationship for salts are provided in 

Sections III and V, respectively. 

A review of the Ecological Incident Information System (EIIS) maintained by the Agency’s 

Office of Pesticide Programs (OPP) indicates a total of 2 reported ecological incidents associated 

with the use of potassium salt formulated products. The reported incidents involved 

phytotoxicity damage to cherry trees (terrestrial plants) that occurred in two counties of 

Washington State in 1989 and 1999. Both incidents were associated with registered uses of soap 

salts and classified as “probable” that the incidents were associated with soap salts exposure. In 

addition, there are 29 aggregate plant incidents reported for potassium salt formulated products 

between 1997 and 2012 that were reported by the pesticide registrants. 

Similarly, a search of the Avian Incident Monitoring System (AIMS; 

http://www.abcbirds.org/abcprograms/policy/toxins/aims/aims/index.cfm) was conducted on 

October 10, 2012. AIMS is a database administered by the American Bird Conservancy that 

contains publicly available data on reported avian incidents involving pesticides. No incidents 

involving soap salts were found. 

III.3.1. Aquatic Effects Characterization 

The most sensitive acute and chronic effects measurement endpoints associated with soap salts 

exposure to freshwater and estuarine/marine species are summarized in Table III.5 for 

potassium and in Table III.6 for ammonium. Selected effects endpoints for the risk assessment 

are from acceptable and supplemental studies for soap salts and are described in Appendix C. 

Laboratory studies examining the effects of salts of fatty acids to aquatic organisms indicated 

that the potassium salt is generally more toxic than the ammonium salt. Based on the most 

sensitive toxicity data, the potassium salt is acutely classified as moderately toxic to freshwater 

fish and estuarine/marine invertebrates; highly toxic to freshwater invertebrates; and no effects 

were seen in estuarine/marine fish at doses up to 4.4 mg a.i./L. The data presented in Table III.9 

are mostly for chain lengths of C14 to C18. These fatty acids are too insoluble in environmental 

water (18 mg/L and lower) to reach the toxicity endpoints shown. 

Ammonium soap salts (Table III.6) are classified as slightly toxic to freshwater fish and both 

freshwater and estuarine/marine invertebrates; and practically nontoxic to estuarine/marine fish 

on an acute basis. Most of the data in Table III.10 are for formulations containing 93% nonanoic 

acid, which is soluble enough in hard water (157 mg/L) to cause exposure in the water column. 

The results of acute toxicity studies with nonanoic acid itself indicate that the LC50 in bluegill 

sunfish is greater than 105 mg/L (MRID 43065301), the LC50 in rainbow trout is 91 mg/L 

(MRID 43065302), and the EC50 in daphnia magna is 96 mg/L (MRID 43065303). These 
31 

results indicate that a fatty acid of defined composition (99.2% C9 and isomer) is less toxic than 

would be indicated by the toxicity data for potassium and ammonium salts of unknown fatty acid 

composition. 

In addition, freshwater fish also act as surrogates for aquatic-phase amphibians in the absence of 

data; therefore, acute toxicity data with freshwater fish indicates potassium and ammonium salts 

are moderately and slightly toxic to aquatic-phase amphibians, respectively. With chronic 

toxicity data limited to the daphnid life cycle studies, reproductive and growth effects in the time 

release of first brood, offspring per adult, and length were observed; however, daphnids’ life 

cycle was more sensitive to potassium salts than ammonium. Acute-to-Chronic Ratio 

calculations were used to estimate the NOAEC for chronic effects to freshwater fish, 

estuarine/marine fish, and estuarine/marine invertebrates, using data from the daphnid and mysid 

studies. 

No aquatic organism toxicity data are available for sodium salts; however, the sodium salts 

product is formulated as mesh bags which are hung on branches or stakes, which results in low 

potential for runoff and spray drift to aquatic organisms/plants. In addressing the lack of toxicity 

data, the required exposure for adverse effects on aquatic organisms/plants exposed to sodium 

salts are discussed further in Section IV.2. 
32 

Table III.5. Most Sensitive Acute and Chronic Toxicity Data for Aquatic Organisms 

Exposed to Potassium Salts of Fatty Acids.1

Exposure 

Scenario 

Species Affected 

Endpoint 

Toxicity Measurement MRID 

(Classification) 

Freshwater Fish 

Acute Rainbow trout 

(Onchorhynchus 

mykiss) 

Mortality 96-hr LC50 = 9.19 mg a.i./L 40053304 

Chronic No data 

available 

Estimated NOAEC = 8.06 mg 

a.i./L 

ACR2

Freshwater Invertebrates 

Acute Water flea 

(Daphnia spp.) 

Immobility 48 hr EC50 = 0.57 mg a.i./L 40053305 

Chronic Reproduction 

and Growth 

NOAEC = 0.5 mg a.i./L 

(offspring/adult and length) 

48664201 

Estuarine/Marine Fish 

Acute Sheepshead 

minnow 

(Cyprinodon 

variegates)

Mortality 96-hr LC50>4.4 mg a.i./L 48469802 

Chronic No studies 

available 

Estimated NOAEC >3.9 mg 

a.i./L 

ACR2

Estuarine/Marine Invertebrates 

Acute Mysid shrimp 

(Americamysis 

bahia) 

Mortality 96-hr LC50 = 1.2 mg a.i./L 48608707 

Chronic No data 

available 

Estimated NOAEC = 1.05 mg 

a.i./L 

ACR2

Aquatic Plants 

7-day 

exposure 

Duckweed 

(Lemna gibba) 

Frond count 7-day EC50: >5.0 mg a.i./L 

NOAEC = 5.0 mg a.i./L 

48608702 

96-hour 

exposure 

Green algae 

(P. subcapitata) 

Cell density 96-hr EC50: 0.59 mg a.i./L 

NOAEC = 0.39 mg a.i./L 

48608701 

1 Tested as formulated product; mostly long-chain (C14-C18 fatty acids). Actual toxicity limited by solubility 

product constant as shown in Table III.1.

2 Estimated value based on Acute to Chronic Ratio (ACR) method using daphnid data; ACR = 1.14. Trout 

NOAEC = (LC50 of 9.19 mg/L ÷ 1.14) = 8.06 mg/L; Minnow NOAEC = (LC50 of >4.4 mg/L ÷ 1.14) = >3.9 

mg/L; Mysid NOAEC = (EC50 of 1.2 mg/L ÷ 1.14) = 1.05 mg/L 

 
33 

Table III.6. Most Sensitive Acute and Chronic Toxicity Data for Aquatic Organisms 

Exposed to Ammonium Salts of Fatty Acids.1

Exposure 

Scenario 

Species Affected 

Endpoint 

Toxicity Measurement MRID 

Freshwater Fish 

Acute Rainbow trout 

(Onchorhynchus 

mykiss) 

Mortality 96-hr LC50 = 12 mg a.i./L 42806405 

Chronic No studies 

available 

Estimated NOAEC = 10.3 mg 

a.i./L 

ACR2

Freshwater Invertebrates 

Acute Water flea 

(Daphnia spp.) 

Immobility 48 hr EC50 = 27 mg a.i./L 42806406 

Chronic Reproduction 

and Growth 

NOAEC = 23 mg a.i./L (time to 

first brood release) 

48402203 

Estuarine/Marine Fish 

Acute Sheepshead 

minnow 

(Cyprinodon 

variegates) 

None 96-hr LC50>105 mg a.i./L 48402202 

Chronic No studies 

available 

Estimated NOAEC = >90 mg 

a.i./L 

ACR2

Estuarine/Marine Invertebrates 

Acute Mysid shrimp 

(Americamysis 

bahia) 

Mortality 96-hr LC50 = 67 mg a.i./L 48402201 

Chronic No data 

available 

Estimated NOAEC = 57 mg 

a.i./L 

ACR2

Aquatic Plants 

7-day 

exposure 

Duckweed 

(Lemna gibba) 

Frond count 7-day EC50= 200 mg a.i./L 

NOAEC = 15 mg a.i./L 

48402206 

96-hour 

exposure 

Green algae 

(P. subcapitata) 

Cell density 96-hr EC50: 6.6 mg a.i./L 

NOAEC = 2.9 mg a.i./L 

48402207 

1 Data are for soluble, short-chain (93% C9) fatty acids. 

2 Estimated value based on Acute to Chronic Ratio (ACR) method using daphnid data; ACR = 1.17. Trout 

NOAEC = (LC50 of 12 mg/L ÷ 1.17) = 10.3 mg/L; Minnow NOAEC = (LC50 of >105 mg/L ÷ 1.17) = >90 

mg/L; Mysid NOAEC = (EC50 of 66.5 mg/L ÷ 1.17) = 57 mg/L

III.3.2. Terrestrial Effects Characterization 

The most sensitive acute and chronic effects measurement endpoints associated with salts 

exposure to terrestrial species are summarized in Table III.7 for potassium and in Table III.8

for ammonium. Selected effects endpoints for the risk assessment are from acceptable and 

supplemental studies for salts and are described below. 

Overall, soap salts are practically nontoxic to birds on an acute basis. After adjusting for purity, 

potassium and ammonium salts caused no mortality or sub-lethal effects up to and including 

2,450 mg a.i./kg bw and 5620 mg a.i./kg diet to upland game birds and waterfowl via oral and 

dietary routes, respectively. In addition, while limited, the 1981 studies with these species also 

indicated no effect to birds in the diet as high as 10,000 mg TEP/kg diet. No acute avian toxicity 

data is available for sodium salts. In addition, birds also act as surrogates for reptiles and 

terrestrial-phase amphibians in the absence of data; therefore, acute toxicity data with birds 

indicates potassium and ammonium salts are practically nontoxic to reptiles and terrestrial-phase 

amphibians. Avian reproduction data for soap salts were not available so the chronic toxicity to 

birds, reptiles, and terrestrial-phase amphibians is unknown; however, the Agency is not asking 
34 

for reproduction data since it is anticipated that the ecological effects to birds are minimal with 

the soap salts undergoing rapid degradation in less than a day and the lack of effects at high rates 

in the acute studies. 

The Office of Pesticide Programs’ Health Effects Division (HED) has waived all generic 

mammalian toxicity data requirements for soap salts due to the lack of effects at high doses in 

the available studies of other fatty acid salts, the nature of the chemicals (fatty acids) and their 

ubiquity in nature, and the limited potential for human exposure via the oral route from 

established uses. With no systemic toxicity observed, HED did not select endpoints for human 

health risk assessment. Thus, for the ecological risk assessment, the ecological effects to 

mammals are anticipated to be minimal.

Results of the acute contact tests with honeybees indicate that formulated products of soap salts 

are practically non-toxic to honeybees. 

Summaries of the toxicity studies are given in Appendix C. 

Table III.7. Most Sensitive Acute and Chronic Toxicity Data for Terrestrial 

Animals Exposed to Potassium Salts of Fatty Acids.

Exposure 

Scenario 

Species Exposure 

Duration 

Toxicity Reference Value MRID 

Mammals 

Acute 

(Dose-based) No mammalian endpoints selected from HED due to lack of effects at high 

doses in available studies of other acid salts, the ecological effects to mammals 

are anticipated to be minimal. 

Chronic 

(Dietarybased) 

Birds 

Acute 

(Dose-based) 

Bobwhite quail 

Colinus 

virginianus

14-day 

single oral 

dose 

LD50 > 2450 mg a.i./kg bw 44980310 

Passerine bird No data available 

Acute 

(Dietarybased) 

Bobwhite quail 

Colinus 

virginianus

8-day 

dietary 

LC50: >5620 mg a.i./kg-diet 40066204 

Chronic 

(Dietarybased) 

No studies available, surrogate data from other salts are used. 

Terrestrial Plants 

Seedling 

emergence 

Ryegrass 

(monocot) 

14 days 

EC25 = >62.34 lbs a.i./A 

NOAEC = 31.17 lbs a.i./A 

48608704 

Radish 

(dicot) 

EC25 = 53.9 lbs a.i./A 

NOAEC = 3.865 lbs a.i./A 

Vegetative 

Vigor 

Corn 

(monocot) 

EC25 = 5.91 lbs a.i./A 

NOAEC = 4.239 lbs a.i./A 

48402302 

Oilseed rape 

(dicot) 

EC25 = 18.5 lbs a.i./A 

EC05 = 4.38 lbs a.i./A 

Beneficial Insects 

Contact Honey bee 48-hours LD50 >100 μg a.i./bee 42806001 
35 

Table III.8. Most Sensitive Acute and Chronic Toxicity Data for Terrestrial 

Animals and Plants Exposed to Ammonium Salts of Fatty Acids.

Exposure 

Scenario 

Species Exposure 

Duration 

Toxicity Reference Value MRID 

Mammals 

Acute 

(Dose-based) No mammalian endpoints selected from HED due to lack of effects at high 

doses in available studies of other acid salts, the ecological effects to mammals 

are anticipated to be minimal. 

Chronic 

(Dietarybased) 

Birds 

Acute 

(Dose-based) 

No data available, surrogate data from other salts are used. 

Acute 

(Dietarybased) 

Japanese quail 

(Cortunix 

japonica) 

8-day dietary LC50: >5000 mg/kg diet or 

1100 mg a.i./kg diet 

46206301 

Chronic 

(Dietarybased) 

No data available, surrogate data from other salts are used. 

Terrestrial Plants 

Seedling 

emergence 

All 4 monocots 

and 6 dicots 

14 days 

EC25 >100 lbs a.i./A 

NOAEC = 100 lbs a.i./A 

48402204 

Vegetative 

Vigor 

Corn (monocot) EC25 = 6.2 lbs a.i./A 

NOAEC = 1.5 lbs a.i./A 

48402205 

Tomato 

(dicot) 

EC25 = 2.2 lbs a.i./A 

EC05 = 1.1 lbs a.i./A 

Beneficial Insects 

Contact Honey bee 48-hours LD50 >100 μg/bee 44766401 
36 

IV. Risk Characterization 

IV.1. Risk Estimation 

Toxicity data and exposure estimates are used to evaluate the potential for adverse ecological 

effects on non-target species. This assessment for soap salts relies on the deterministic RQ 

method to provide a metric of potential risks, for terrestrial plants, fish and aquatic invertebrates. 

The RQ provides a comparison of exposure estimates to toxicity endpoints (i.e., the estimated 

exposure concentrations are divided by acute and chronic toxicity values). The resulting RQs are 

compared to the Agency’s LOCs, as shown in Table II.8. LOCs are used by the Agency to 

indicate when the use of a pesticide, as directed by the label, has the potential to cause adverse 

effects to non-target organisms. Due to a lack of toxicity, RQs are not calculated for mammals 

or birds. These risks will be considered qualitatively. 

IV.1.1 Risk Quotient Calculations for Aquatic Organisms 

There is a potential for exposure of the active ingredients to aquatic organisms. Toxicity 

information on the percentage of the active ingredient in the formulations is used to estimate the 

risks to aquatic organisms as a result of surface runoff and spray drift from broadcast ground 

applications. RQs for spot treatment applications were not calculated. The LD50 and EC50 is used 

to estimate acute risk for adverse effects on survival to fish and invertebrates, respectively, and 

the NOAEC is used to estimate chronic risk for adverse effects on reproduction and growth to 

both fish and invertebrates. A single broadcast ground application is modeled. Applications from 

spot treatments were not modeled. 

Freshwater Fish and Invertebrates 

Tables IV.1 and IV.2 list acute and chronic RQs calculated for freshwater fish (also surrogates 

for aquatic-phase amphibians) and invertebrates exposed to potassium and ammonium salts, 

respectively, based on the EECs generated from GENEEC modeling. Exposures for potassium 

salts (long-chain fatty acids) may be limited by precipitation with metal cations in natural water, 

thus the exposures in Table IV.1 may not be realized. 

Results of the assessment on freshwater organisms indicate no acute LOC exceedances for 

freshwater fish exposed to soap salts (Table IV.1 – potassium; Table IV.2 - ammonium); the 

highest acute RQ was 0.04. No chronic toxicity data were available for freshwater fish. The acute 

to chronic ratio method was used to estimate the chronic toxicity value for freshwater fish using 

data from rainbow trout and daphnid studies. Chronic RQs (highest RQ = <0.01) for freshwater 

fish exposed to soap salts were below the chronic LOC at the maximum broadcast applications 

rate. The data gap is discussed further in Section IV.2. 

The acute RQs for freshwater invertebrates exposed to potassium salts exceeded the acute listed 

species and restricted use LOCs when applying at and greater than the application rate of 20 lb 

a.i./A using ground equipment (acute RQ = 0.49) and exceeded the acute listed species, restricted 

use, and acute non-listed species LOCs when applying at and greater than 27 lb a.i./A (acute RQ 

= 0.66). However, the potassium salts (predominantly longer-chain fatty acids) may not be 

soluble enough for these effects to be seen in the open environment. When compared to toxicity 
37 

data for 99.2% nonanoic acid (MRIDs 43065302 and -03), however, the acute risk quotients are 

below Agency levels of concern. The acute freshwater fish RQ is 0.378/91 (EEC/toxicity) = 

0.004, and the Daphnia acute RQ is 0.378/96= 0.004. Chronic RQs (highest RQ = 0.2) for 

freshwater invertebrates exposed to potassium salts are below the Agency’s LOC of 1 for chronic 

risk when applied at and greater than 27 lb a.i./A when using broadcast ground equipment. 

The acute and chronic RQs for freshwater invertebrates exposed to ammonium salts are below 

the Agency’s LOCs; the highest RQ was 0.01. The potential risks to freshwater organisms are 

discussed further in Section IV.2. 

 
38 

 

Table IV.1. Risk Quotients for Freshwater Organisms for Potassium Salts of Fatty Acids

Use

(# apps/ 

lb a.i./A)

Peak 

EEC 

21D 

EEC 

60D 

EEC 

Solubility 

Limit 

(C12-

C18) 

Freshwater Fish

(LC50 = 9.19 mg a.i./L; 

NOAEC = No data, 

ACR = 8.06 mg a.i./L)

Freshwater Invertebrate

(EC50 = 0.57 mg a.i./L; 

NOAEC = 0.5 mg a.i./L)

(mg a.i./L) Acute Chronic Acute* Chronic

1 ground app 

@ 27 0.378 0.1 0.0378 

2.7 – 

0.00074 

0.04 <0.01 0.66*** 0.2 

1 ground app 

@ 20 0.28 0.076 0.028 0.03 <0.01 0.49** 0.15 

1 ground app 

@ 10 0.14 0.038 0.014 0.02 <0.01 0.25** 0.08 

1 ground app 

@ 1.0 0.014 0.0038 0.0014 0.0015 <0.01 0.02 0.01 

* Depending on fatty acid mixture, soap salt may not be soluble enough for this effect to be observed. ** Exceeds the 

restricted use LOC of 0.1 and the listed species LOC of 0.05; and *** Exceeds the nonlisted species, restricted use, and 

listed species LOCs of 0.5, 0.1, and 0.05, respectively.

Table IV.2. Risk Quotients for Freshwater Organisms for Ammonium Salts of Fatty Acids 

Use

(# apps/ lb a.i./A)

Peak 

EEC

21D 

EEC

60D 

EEC

Freshwater Fish

(LC50 = 12 mg a.i./L; 

NOAEC = No data, 

ACR = 10.3 mg 

a.i./L)

Freshwater Invertebrate

(EC50 = 27 mg a.i./L ; 

NOAEC = 23 mg a.i./L)

(mg a.i./L) Acute Chronic Acute Chronic

1 ground app @ 27 0.378 0.1 0.0378 0.03 <0.01 0.01 <0.01 

1 ground app @ 20 0.28 0.076 0.028 0.02 <0.01 0.01 <0.01 

1 ground app @ 10 0.14 0.038 0.014 0.01 <0.01 <0.01 <0.01 

1 ground app @ 1.0 0.014 0.0038 0.0014 0.001 <0.01 <0.01 <0.01 

Estuarine/Marine Fish and Invertebrates 

Tables IV.3 and IV.4 list acute and chronic RQs calculated for estuarine/marine fish and 

invertebrates exposed to potassium and ammonium salts based on the EECs generated from 

GENEEC modeling. 

The acute RQs for estuarine/marine fish exposed to potassium salts were not calculated since no 

effects were observed at the maximum dose tested in the toxicity studies with sheepshead 

minnows. This may be due to precipitation of the fatty acids by metal ions in the salt water. 

Exposed to potassium salts, the acute RQ of 0.1 for estuarine/marine invertebrates exceeded the 

restricted use and acute listed species LOCs of 0.1 and 0.05, respectively, when applying at and 

greater than 10 lb a.i./A. At 27 lb a.i./A, the highest broadcast application rate, the acute RQ was 
39 

as high as 0.3. None of the chronic RQs exceeded the chronic LOC of 1.0 for estuarine/marine 

invertebrates exposed to potassium salts; the highest chronic RQ was 0.09. Exposures may not 

reach the levels indicated, due to precipitation by metal ions. 

Acute and chronic RQs for uses of ammonium salts were below the Agency’s LOCs for 

estuarine/marine organisms exposed to the salt as a result of broadcast ground applications; 

therefore, RQs based on other uses with lower application rates of ammonium salts are also less 

than the LOC. 

No chronic toxicity data were available for estuarine/marine organisms. The acute to chronic 

ratio method was used to estimate the chronic toxicity value for estuarine/marine fish and 

invertebrates using data from sheepshead minnow, daphnid, and mysid studies. None of the 

ACR-derived NOAECs values resulted in chronic LOC exceedances for estuarine/marine 

organisms exposed to soap salts. The data gap is discussed further in Section IV.2. 

The potential risks to estuarine/marine organisms are discussed further in Section IV.2. 

 

Table IV.3. Risk Quotients for Estuarine/Marine Organisms for Potassium Salts of Fatty Acids

Use

(# apps/ 

lb a.i./A)

Peak 

EEC

21D 

EEC

60D 

EEC

Estuarine/marine Fish

(LC50 >4.4 mg a.i./L;

NOAEC = no data, 

ACR >3.9 mg a.i./L)

Estuarine/marine 

Invertebrates

(EC50 = 1.2 mg a.i./L;

NOAEC = no data, ACR 

= 1.05 mg a.i./L)

(mg a.i./L) Acute Chronic Acute* Chronic

1 ground app @ 27 0.378 0.1 0.0378 

RQs not 

calculated 

due to no 

effects at 

the 

solubility 

limit 

RQs were 

not 

derived 

due to a 

nondefinitive 

NOAEC 

using 

ACR 

method 

0.3** 0.09 

1 ground app @ 20 0.28 0.076 0.028 0.2** 0.07 

1 ground app @ 10 0.14 0.038 0.014 0.1** 0.04 

1 ground app @ 1.0 0.014 0.0038 0.0014 0.01 <0.01 

* Depending on fatty acid mixture, soap salt may not be soluble enough for this effect to be observed; ** Exceeds the 

nonlisted species LOC of 0.5 and the listed species LOC of 0.05. 
40 

Table IV.4. Risk Quotients for Estuarine/marine Organisms for Ammonium Salts of Fatty Acids 

Use

(# apps/ lb 

a.i./A)

Peak 

EEC

21D 

EEC

60D 

EEC

Estuary Fish

(LC50 >105 mg a.i./L;

NOAEC = no data, ACR >90 

mg a.i./L)

Estuary Invertebrate

(EC50 = 67 mg a.i./L;

NOAEC = no data, ACR = 57 

mg a.i./L)

(mg a.i./L) Acute Chronic Acute Chronic

1 ground app @ 

27 0.378 0.1 0.038 

RQs not 

calculated 

due to no 

effects at the 

maximum 

dose

RQs were not 

derived due to 

a nondefinitive 

NOAEC using 

ACR method 

<0.01 <0.01 

IV.1.2 Risk Quotient Calculations for Aquatic Plants 

There is a potential for exposure of the active ingredients to aquatic vascular and nonvascular 

plant species, toxicity information on the percentage of the active ingredient in the TEP are used 

to estimate the risks to aquatic plants as a result of surface runoff and spray drift from broadcast 

ground applications. The EC50 is used to estimate risk for adverse effects on growth to non-listed

aquatic plants and the NOAEC (or EC05 when a NOAEC is not available) is used to estimate risk 

for adverse effects on growth to listed aquatic plants. 

Non-listed and Listed Aquatic Plants 

According to peak GENEEC EEC and the range of application rates for broadcast ground 

application and toxicity values of the salts, the nonlisted and listed RQs for aquatic plants (both 

vascular and nonvascular species) are below Agency’s plant LOC of 1.0 (Table IV.5). RQs were 

not derived for non-listed aquatic vascular plants because only non-definitive EC50s are available 

and the risks to these species are discussed further in the Risk Description section. 

RQs for uses of ammonium salts at the maximum label rate of 27 lb a.i./A fall below the 

Agency’s plant LOCs for aquatic plants (both vascular and nonvascular) exposed to ammonium 

salts via broadcast ground applications (Table IV.6); therefore, RQs based on other uses with 

lower application rates of ammonium salts are also less than the LOC. 

The potential risks to aquatic plants are discussed further in Section IV.2. 

Table IV.5. Risk Quotients for Aquatic Plants for Potassium Salts of Fatty Acids* 

Use

(# apps/lb a.i./A)

Peak EEC Vascular Aquatic Plant

(EC50 >5.0 mg a.i./L

NOAEC = 5.0 mg a.i./L)

Non-Vascular Aquatic 

Plant

(EC50 = 0.59 mg a.i./L;

NOAEC = 0.39 mg a.i./L)

(mg a.i./L) Non-Listed Listed Non-Listed Listed

1 ground app @ 27 0.378 RQs not 

calculated 

0.07 0.64 0.96 

1 ground app @ 20 0.28 0.06 0.44 0.72 
41 

1 ground app @ 10 0.14 due to no 

effects at 

the 

solubility 

limit 

0.03 0.2 0.4 

1 ground app @ 1.0 

0.014 0.003 0.02 0.04 

 *Depending on fatty acid mixture, soap salt may not be soluble enough for this effect to be observed. 

Table IV.6. Tier II Risk Quotients for Aquatic Plants for Ammonium Salts of Fatty Acids 

Use

(# apps/lb a.i./A)

Peak EEC Vascular Aquatic Plant

(EC50 = 200 mg a.i./L

NOAEC = 15 mg a.i./L)

Non-Vascular Aquatic 

Plant

(EC50 = 6.6 mg a.i./L;

NOAEC = 2.9 mg a.i./L)

(mg a.i./L) Non-Listed Listed Non-Listed Listed

1 ground app @ 27 0.378 <0.1 <0.1 <0.1 < 0.1 

IV.1.3. Risk Quotient Calculations for Terrestrial Animals 

For this screening-level risk assessment with birds and mammals, acute and chronic RQs are 

derived based on ecological toxicity data for formulations of soap salts (e.g. potassium and 

ammonium salts of fatty acids), and then directly compared to the dietary-based EECs generated 

from T-REX. For dose-based RQs, the EECs and toxicity values are first adjusted based on food 

intake and body weight differences of the terrestrial animals prior to the assessment. The LD50

and LC50 are used to estimate acute risk for adverse effects on survival to both birds and 

mammals; the NOAEC is used to estimate chronic risk for adverse effects on reproduction and 

growth to both birds and mammals. 

Birds

There is a potential for acute exposure to birds via the oral and dietary routes, but acute RQs 

were not calculated because toxicity information on the potassium and ammonium salt TEPs 

were not established (potassium: acute oral LD50s >2450 mg a.i./kg-bw (quail); acute dietary 

LC50s were >2450 mg a.i./kg-diet to >10,000 mg TEP/kg-diet (quail and duck); ammonium: 

acute dietary LC50 >5,000 mg/kg diet). 

No chronic reproduction data were available to assess the toxicity of the active ingredients to 

birds; thus, chronic RQs were not calculated. Back calculating for the chronic toxicity value 

using highest T-REX EEC and LOC of 1.0 for chronic risk to birds calculates a toxicity value 

(NOAEC) of >6480 mg/kg-diet based on the maximum application rate for broadcast ground 

applications, respectively, is needed for the RQ to not exceed the LOC. The potential risk for 

acute and chronic exposure to birds is discussed in the Risk Description section. 

Terrestrial-phase Amphibians and Reptiles 

EFED currently uses surrogate data (birds) for terrestrial amphibians and reptiles when data are 

not available. Risks are discussed in the Risk Description section. 
42 

Mammals 

Acute and chronic RQs were not calculated because no mammalian toxicity data are available for 

the soap salts. The potential risk for acute and chronic exposure to mammals is discussed in the 

Risk Description section. 

Beneficial Insects 

Honey bee toxicity data was available, and this was used as a surrogate for terrestrial 

invertebrates. The data, for ammonium and potassium formulations, indicate that the highest 

observed mortality in bees (30%) was at a dose of 262 micrograms per bee, applied to the thorax. 

This is equivalent to an exposure of 2047 mg/kg body weight. The highest broadcast application 

rate is 27 lb/A, equivalent to 2538 mg/kg exposure to arthropods. Thus, the 27 lb/A rate is 

slightly higher than the dose causing 30% mortality. At 30 feet offsite, the exposure from spray 

drift is 1.0 lb/A or 94 mg/kg to arthropods, which corresponds to about 10 to 15% mortality in 

the laboratory tests. Thus, mortality effects to invertebrates are not expected at great distances 

from the application site, especially as label use instructions direct the user to thoroughly wet 

leaves, top and bottom, which is not likely as a result of spray drift. 

IV.1.4. Risk Quotient Calculations for Terrestrial Plants in Terrestrial 

and Semi-aquatic Environments 

For this risk assessment with terrestrial monocots and dicots, Non-listed and listed plant species 

RQs are derived based on ecological toxicity data for the active ingredients and then compared to 

the TERRPLANT EECs for plants in non-target area receiving surface runoff combined with 

spray drift adjacent to the target area. Details of the TERRPLANT model and EECs are 

presented in Table II.11. 

There is a potential for exposure of the active ingredients to terrestrial plants; toxicity 

information on the formulations are used to estimate the risks to non-target (non-listed) terrestrial 

plants inhabiting dry or semi-aquatic areas adjacent to a treated field as a result of surface runoff 

and/or spray drift. The EC25 was used to estimate risk for adverse effects on growth to non-listed

plant species while the NOAEC (or EC05 when a NOAEC is not available) was used to estimate 

risk for adverse effects on growth to listed plant species. Note: TerrPlant does not consider 

exposures to plants from multiple pesticide applications; thus, results are based on single 

pesticide applications.

Non-listed and Listed Terrestrial Plants 

For terrestrial plants, the vegetative vigor and seedling emergence data show that soap salts are 

more toxic to plants when the foliage is exposed to spray drift, than by exposure through the 

roots as a result of surface water runoff. A commenter indicated that herbicidal soaps are 

effective only when they thoroughly contact the foliage, and are not effective by root uptake. 

Since the main route of exposure to non-target terrestrial plants is by spray drift, not by runoff, 

the LOC exceedance for potential risk to plants inhabiting dry and semi-aquatic areas exposed to 

runoff can be discounted, because the risk quotient is low compared to the level of concern (1.5 
43 

vs. 1.0) and it does not account for degradation of the fatty acids. Spray drift exposure analysis 

(Tier 1 AgDrift, High boom, fine to medium-coarse spray, 90th percentile) indicates that when 

ground-based application methods are used, exposure falls to the 5% effect level (1.0 lb/A) for 

the most sensitive plants less than 30 feet off-site. This indicates that effects to terrestrial plants 

do not occur far from the site of application. 

Tables IV.8 and IV.9 present RQs for the formulated products of potassium and ammonium 

salts, respectively, to terrestrial plants via ground spray applications. 

RQs (1.09-1.47) for listed dicots inhabiting semi-aquatic areas adjacent to a treated site exceed 

the plant LOC of 1.0 when exposed to a combination of surface water runoff and spray drift 

resulting from broadcast ground applications of potassium salts at a rate of 20 lb a.i./A and 

higher. However, listed dicots inhabiting dry areas adjacent a treated field are not impacted 

significantly; highest RQ was 0.21. There are no LOC exceedances for non-listed dicots exposed 

to potassium salts at any rate; highest RQ was 0.11. 

There are no exceedances for nonlisted or listed monocots inhabiting dry and semi-aquatic areas 

adjacent to a treated field exposed to potassium soap salts through a combination of surface 

water runoff and spray drift as well as spray drift alone. 

There are no exceedances for nonlisted or listed monocots or dicots inhabiting dry and semiaquatic areas adjacent to a treated field exposed to ammonium soap salts through a combination 

of surface water runoff and spray drift as well as spray drift alone. 

The potential risks to terrestrial plants are discussed further in the Risk Description section. 

Table IV.8. Terrestrial Plant Risk Quotient Summary for Potassium 1, 2, 3, 4 

Scenario 

Non-listed RQs Listed RQs 

Terrestrial 

Adjacent area 

Semi-aquatic 

Adjacent area Drift Terrestrial Adjacent area

Semi-aquatic 

Adjacent area Drift 

One Ground Spray at Maximum Labeled Rate for Potassium Salt at 27 lb a.i./A 

Monocot <0.1 <0.1 <0.1 <0.1 0.18 <0.1 

Dicot <0.1 0.11 <0.1 0.21 1.47 <0.1 

One Ground Spray of Potassium Salt at 20 lb a.i./A 

Monocot <0.1 <0.1 <0.1 <0.1 0.13 <0.1 

Dicot <0.1 <0.1 <0.1 0.16 1.09 <0.1 

One Ground Spray of Potassium Salt at 10 lb a.i./A 

Monocot <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 

Dicot <0.1 <0.1 <0.1 <0.1 0.54 <0.1 1 RQs for ground spray applications in this table were calculated using the maximum application rates for 

potassium (205 lb a.i./A) salt uses and the general “bin” rates created in the problem formulation. 

2

 Non-listed potassium salt toxicity thresholds (EC25) were 62.34, 53.9, 5.91, and 18.5 lb a.i./A for seedling 

emergence monocot, seedling emergence dicot, vegetative vigor monocot, and vegetative vigor dicot. 

3

 Listed potassium salt toxicity thresholds (NOAEC) were 31.17, 3.865, 4.239, and 4.38 lb a.i./A for seedling 

emergence monocot, seedling emergence dicot, vegetative vigor monocot, and vegetative vigor dicot. 

4 Values in bold are LOC exceedances. 

 
44 

Table IV.9. Terrestrial Plant Risk Quotient Summary for Ammonium Salts 1, 2, 3, 4

Scenario 

Non-listed RQs Listed RQs 

Terrestrial 

Adjacent area 

Semi-aquatic 

Adjacent area Drift Terrestrial Adjacent area

Semi-aquatic 

Adjacent area Drift 

One Ground Spray at Maximum Labeled Rate for Ammonium Salt at 27 lb a.i./A 

Monocot <0.1 <0.1 <0.1 <0.1 <0.1 0.18 

Dicot <0.1 <0.1 0.12 <0.1 <0.1 0.25 

One Ground Spray of Ammonium Salt at 20 lb a.i./A 

Monocot <0.1 <0.1 <0.1 <0.1 <0.1 0.13 

Dicot <0.1 <0.1 <0.1 <0.1 <0.1 0.18 

One Ground Spray of Ammonium Salt at 10 lb a.i./A 

Monocot <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 

Dicot <0.1 <0.1 0.23 <0.1 <0.1 <0.1 

1 RQs for ground spray applications in this table were calculated using the maximum application rates for 

ammonium (103.8 lb a.i./A) salt uses and the general “bin” rates created in the problem formulation. 

2

 Non-listed ammonium salt toxicity thresholds (EC25) were >100, >100, 6.2, and 2.2 lb a.i./A for seedling 

emergence monocot, seedling emergence dicot, vegetative vigor monocot, and vegetative vigor dicot. 

3

 Listed ammonium salt toxicity thresholds (NOAEC) were 100, 100, 1.5, and 1.1 lb a.i./A for seedling emergence 

monocot, seedling emergence dicot, vegetative vigor monocot, and vegetative vigor dicot. 

4 Values in bold are LOC exceedances. 

IV.2. Risk Description 

The risk hypothesis states that the use of the potassium, ammonium, and sodium salts of fatty 

acids as an insecticide, acaricide, herbicide, algaecide and mammal repellant for terrestrial crop 

sites has the potential to adversely affect survival, reproduction, and/or growth of non-target 

aquatic and terrestrial animals and plants, including Federally-listed endangered and threatened 

species. Results are based on a single broadcast ground application. Aerial or spot treatment 

applications were not modeled. 

Based on the LOC exceedances from available ecotoxicity data and predicted environmental 

exposures of the registered uses of potassium salts, the exceedances are for potential acute 

effects to aquatic invertebrates (freshwater and estuarine/marine species) and terrestrial plants 

(semi-aquatic areas only) starting at the application rate of 10 lb a.i./A and higher for 

invertebrates and that the exceedance starts at 20 lb a.i./A and higher for terrestrial plants. 

No LOC were triggered for ammonium salts uses. 

For sodium salts in mesh bags, no LOC exceedances occurred. 

LOCs were not exceeded for beneficial insects, estuarine/marine fish, and aquatic vascular plants 

exposed to potassium or ammonium salts. 
45 

The following sections discuss the potential risks of the soap salts to these taxonomic groups; 

however, because of the additional data provided during the public comment period and the 

numerous uncertainties raised when interpreting the potential risks from spot treatment 

applications labeled at those high application rates, only broadcast applications will be analyzed. 

While not analyzed quantitatively, spot treatment applications are subsequently discussed as to 

whether any meaningful exposures to the receptors are likely as well. 

 IV.2.1 Exposure to Aquatic Organisms 

Due to the high variability in the application rates and the inability to categorize uses by 

application rates, GENEEC2, a tier I model was used to conservatively estimate surface water 

EECs as a result of broadcast applications of potassium and ammonium salts using maximum 

and a range of broadcast application rates coupled with the representative solubility. A single 

broadcast ground application was modeled. Environmental fate data were limited and largely 

based on EpiSuite estimates. The modeling was meant to represent nonanoic acid, a soluble 

fatty acid that is a major constituent of many ammonium salt products. 

For sodium salts in mesh bags, it is unlikely aquatic organisms would be exposed to biologically 

significant concentrations of sodium salts in the environment as a result of surface water runoff 

and offsite spray drift; thus, aquatic organisms are excluded as aquatic receptors in this 

assessment and the adverse affects to aquatic organisms are anticipated to be minimal. 

 IV.2.1.1 Risks to Aquatic Organisms 

Potassium and Ammonium Salts of Fatty Acids 

The screening-level risk assessment on aquatic organisms exposed to both potassium and 

ammonium salts applied at the highest broadcast application rate of 27 lb a.i./A indicates none of 

the taxa except for aquatic invertebrates inhabiting freshwater and estuarine/marine water bodies 

adjacent to a treated field with potassium salts exceeds the Agency’s LOCs for potential adverse 

effects. 

For both freshwater and estuarine/marine invertebrates exposed to potassium salts, the LOC 

exceedances start at 10 lb a.i./A and higher with these acute RQs ranging 0.1 – 0.66. The highest 

RQ for freshwater and estuarine/marine invertebrates was 13.2x and 6x, respectively, above the 

listed species LOC of 0.05. However, because the fatty acids represented by these data have 

limited solubility in environmental water, it is unlikely that adverse effects will be observed. 

The Agency believes there is no likely direct effect to aquatic organisms, for fatty acid salts of 

chain length C14 and higher, because such fatty acids are not sufficiently soluble in 

environmental water for toxic effects to be expressed. For shorter chain-length fatty acids (C9 – 

C11) there is uncertainty, because the available toxicity data is not clear as to what chain-length 

mixtures were tested. However, acute toxicity data for nearly pure nonanoic (pelargonic) acid, 

which is representative of the shorter chain-length fatty acids, indicate that it does not reach 

levels of concern with a Tier I exposure assessment. Overall, the Agency anticipates it is unlikely 

that soap salts as a group will cause direct effects to listed aquatic species. 

For ammonium salts, there were no LOC exceedances for any of the aquatic taxa (acute RQs 

<0.01-0.03). 
46 

For estuarine/marine fish exposed to both salts, acute and chronic RQs were not derived in the 

Risk Estimation section of this assessment. Because no mortality to sheepshead minnows was 

observed at the maximum dose of 105 mg a.i./L and at the solubility limit of 4.4 mg a.i./L for 

ammonium and potassium salts formulations, respectively, the acute risks to estuarine/marine 

fish are anticipated to be minimal. The chronic RQs were not derived for estuarine/marine fish 

due to a non-definitive NOAEC calculated from the ACR method using minnow and daphnid 

data. A comparison of the non-definitive NOAEC at the solubility limit (>3.9 mg/L potassium 

salts; >105 mg/L ammonium salts (P/A)) with the highest GENEEC 60-day EEC (0.038 mg/L) 

indicates the estuarine/marine fish NOAEC is 103x/>1000x (P/A) greater than the 

environmentally relevant concentrations; thus, the chronic risks to estuarine/marine fish adjacent 

a treated field exposed to broadcast ground applications of soap salts are anticipated to be 

minimal as well. 

RQs were not derived for aquatic vascular plants, in the Risk Estimation section of this 

assessment because none of the non-target vascular plants were inhibited 50% or more in the 

duckweed studies (i.e., >5.0 mg a.i./L). However, for non-vascular plants, no LOC was 

exceeded. Thus, the risks to aquatic plants adjacent a treated field exposed to broadcast ground 

applications of soap salts are expected to be minimal. 

An uncertainty to this chronic risk assessment still exists because the chronic RQs were based on 

these ACR-estimated toxicity values in absence of data; yet, soap salts would need to be 212x to 

271x (Potassium/Ammonium) more toxic to freshwater fish, 103x to >1000x 

(Potassium/Ammonium) more toxic to estuarine/marine fish, and 10.5x to 570x 

(Potassium/Ammonium) more toxic to estuarine/marine invertebrates from a single application 

to be risks of concern. However, the labels are unclear on the number of applications allowed 

and do not appear to limit the maximum number of applications per year or define a 

recommended minimum interval between applications. Repeat applications may be needed in 

order to control pest infestations, potentially resulting in higher longer-term (chronic) average 

exposure concentrations. In making the assumption, the concentrations were analyzed as to 

whether additional applications at three, ten, or more applications coupled with the shortest 

reapplication interval of 7 days could result in higher exposure to aquatic organisms that may 

exceed the chronic LOC. Table IV.10 presents the aquatic EECs calculations generated from 

GENEEC2 for multiple ground applications of soap salts. Model defaults were used. The 

maximum soap salt application rate at 205 lb a.i./A (used for spot treatments only) was used. As 

LUIS reported no aerial uses at those high application rates, the aerial applications were 

excluded from the assumption. Results indicate the concentrations increased 3% when applied 10 

or 50 times, respectively, and if 50 applications made weekly translates to a small increase in 

concentrations, higher long-term exposures to aquatic organisms from repeated applications are 

unlikely. Thus, based on the available information, addressing the data gap of reproduction 

studies with aquatic organisms would be unlikely to change the risk conclusions for aquatic 

organisms from chronic exposure to soap salts; the agency is not asking for chronic toxicity data 

to address the uncertainty because it is not likely that chronic exposure with repeated 

applications would increase enough in the long term to affect aquatic organisms. 
47 

Table IV.10. Exposure Estimates (ppm) for Soap Salts modeled as 

Nonanoic Acid 

Application Rate 

 (lb a.i./A) and no. 

of applications

Peak 21-Day Avg 60-Day Avg

Ground Application 

205 x 1 2.9 0.79 0.28 

205 x 3 3.0 0.84 0.3 

205 x 10 3.0 0.84 0.3 

205 x 25 3.0 0.84 0.3 

205 x 50 3.0 0.84 0.3 

IV.2.1.1.1. Aquatic Organisms Exposed to Soap Salts As a Result 

of Spot Treatment Applications 

There is uncertainty with the aquatic risk assessment for some spot treatment uses, particularly 

those with the highest application rates (205 lb/acre). EFED has modified the aquatic risk 

assessment for spot treatment uses using an assumption that the high rates are broadcast (Table 

IV.11). EFED believes that exposure estimates for aquatic resources are overly conservative for 

spot treatments because the underlying assumption in the aquatic models is that 100% of the 

field is treated with the pesticide. In order to better characterize the importance of the 100% area 

treated assumption on the overall risk conclusions, an estimate of the area threshold of spot 

treatment for each taxon where the LOC would no longer be exceeded is given. 

As an example, it is estimated that for the highest application rate (i.e. 205 lbs a.i./acre) the spot 

area treated would need to exceed 16% of the total area for the LOC to be exceeded for 

freshwater fish. However, EFED does not have information on typical spot treatment area 

percentages. Also, the labels that do specify spot treatment and the total area the container can 

cover (square feet) can be compared with Table IV.11 to determine whether effects are possible 

from these uses. 

Again, the Agency believes there is no direct effect to aquatic organisms, for fatty acid salts of 

chain length C14 and higher, because such fatty acids are not sufficiently soluble in 

environmental water for toxic effects to be expressed. For shorter chain-length fatty acids (C9 – 

C11), levels of concern are not exceeded with a Tier I exposure assessment. It is unlikely that 

soap salts used as a spot treatment using backpack sprayers will cause direct effects to listed 

aquatic species. 
48 

Table IV.11 Area Percentage of Application Needed to Exceed the LOC 

Taxa Application 

rates 

(lb a.i./A) 

RQs assuming 

100% area 

treated (highest 

to lowest)* 

LOC Area Percentage of 

application needed to 

exceed LOC1

Potassium Salts 

Freshwater fish 

(acute effects) 

205 0.3 

Acute = 0.05 

16% 

116 0.2 25% 

63 0.1 50% 

10 0.02 No exceedance 

Freshwater 

invertebrates 

(acute effects) 

205 5 

Acute = 0.05 

1% 

116 3 2% 

63 2 3% 

10 0.3 17% 

1 0.03 No exceedance 

Estuarine/marine fish 

(acute effects) 

None No effects; RQ 

not calculated Acute = 0.05 No exceedance 

Estuarine/marine 

invertebrates 

(acute effects) 

205 2 

Acute = 0.05 

3% 

116 1 5% 

63 1 5% 

10 0.1 50% 

1 0.01 No exceedance 

Freshwater fish 

(chronic effects) 205 0.04 Chronic = 1.0 No exceedance 

Estuarine/marine fish 

(chronic effects) 

None Non-definitive 

endpoint; RQ not 

calculated 

Chronic = 1.0 No exceedance 

Freshwater invertebrate 

(chronic effects) 

205 2 

Chronic = 1.0 

50% 

116 1 100% 

63 0.5 No exceedance 

Estuarine/marine 

invertebrates 

(chronic effects) 

205 0.8 Chronic = 1.0 No exceedance 

Aquatic vascular plants 

(non-listed and listed 

effects) 

None No 50% 

inhibition; RQ 

not calculated 

Non-listed plants = 1.0 

No exceedance 

0.6 Listed plants = 1.0 No exceedance 

Aquatic nonvascular 

plants 

(non-listed and listed 

effects) 

205 5 

Non-listed plants = 1.0 

20% 

116 3 33% 

63 2 50% 

10 0.3 No exceedance 

205 7 

Listed plants = 1.0 

14% 

116 4 25% 

63 2 50% 

10 0.4 No exceedance 

*Bold values indicate LOC exceedance 

1 The threshold percentage is assessed to determine how much percent of exposure that RQ needs to exceed the LOC. 

For example, the highest acute RQ for freshwater invertebrates inhabiting a pond adjacent a field applied at 205 lb 

a.i./A is 5 which is 100 times higher than the listed species LOC of 0.05; to assess the % of exposure needed at which 

the LOC exceedance occurred, results indicate 1% is needed for the RQ to exceed the LOC. A “no effect” or “may 

affect” determination was not made since it is unknown what % of an actual area is typical spot treatment. 
49 

 IV.2.2. Exposure to Terrestrial Wildlife 

In the conceptual model, dietary ingestion of potassium and ammonium salts residues on 

vegetative matter and insects on treated areas as depicted in Figure 1 are predicted as the most 

likely sources of exposure to terrestrial animals. Spray drift, runoff and wind erosion of soil 

particles with resulting residues on upland and/or wetland foliage and soil are the most likely 

sources of potassium and ammonium salts exposure to non-target terrestrial plants, including 

Federally-listed endangered and threatened species. 

Direct ingestion of sodium salts mesh bags on treated areas would be predicted as the most likely 

source of exposure to wildlife because it is unlikely that significant concentrations of sodium 

salts would be found on vegetative matter and insects. However, the repellent is not meant to be 

ingested, but works by producing an odor that wildlife do not like. Thus, based on the use pattern 

(suspended mesh bags), the low use rate (one ounce per bag), and the mode of action (mammal 

repellency), meaningful exposure of wildlife to the sodium salts is not anticipated. 

 IV.2.2.1 Risks to Birds 

Available avian acute toxicity data indicates that the soap salts are practically nontoxic to upland 

game birds and waterfowls on an acute basis via either or both oral and dietary routes. Acute 

RQs were not derived for birds in the Risk Estimation section of this assessment due to the nondefinitive endpoints observed in the acute oral and dietary avian studies. Furthermore, numerous 

ecological studies observed no mortality or sub-lethal effects in birds at doses as high as 5,000 - 

10,000 mg/kg diet, so the potential for acute risk to birds from exposure to potassium and 

ammonium salts is expected to be low. 

Chronic RQs were not calculated because sub-lethal effects data were not available. The Agency 

is not asking for toxicity data to evaluate the reproductive risks to birds due to the salts 

undergoing rapid degradation via metabolism in less than a day and the lack of effects at high 

rates in the acute avian studies. 

In addition, fatty acids are a major component in wildlife diets.1

 Fatty acids or animal fats are 

also consumed in humans.2

 In addition, potassium salts is recognized by the FDA as a 

“Generally Recognized As Safe” (GRAS) food additive.3

 It is anticipated that significant 

exposure of birds to soap salts is unlikely. 

 IV.2.2.2 Risks to Mammals 

Acute and chronic RQs were not derived for mammals in the Risk Estimation section of this 

assessment because no mammalian toxicity data were available for the soap salts. Since HED did 

not select any endpoints for the human health assessment due to no systemic toxicity observed at 

high rates, EFED presumes the ecological effects to mammals are expected to be minimal. 

 

1

 http://npic.orst.edu/factsheets/psfagen.pdf 

2

 http://www.heart.org/HEARTORG/GettingHealthy/FatsAndOils/Fats101/PolyunsaturatedFats_UCM_301461_Article.jsp 

3

 Food Additives Permitted for Direct addition to Food for Human Consumption. Code of Federal Regulations, Part 

172.863, title 21, 1998. 
50 

 IV.2.2.3 Potential Effects to Terrestrial Invertebrates 

The available terrestrial insect toxicity data, based on tests with honeybees, indicate that the 

formulated products containing soap salts are practically non-toxic to bees on an acute contact 

basis. The highest LD50 value for potassium and ammonium salts was >100 μg a.i./bee. 

However, other terrestrial arthropods or invertebrates could be impacted since potassium salts 

are registered as an insecticide and acaricide. Ammonium and sodium salts are not registered for 

use as an insecticide. With no toxicity data available for terrestrial invertebrates, honey bees 

were used as a surrogate. In making this assumption for terrestrial invertebrates, the weight of a 

bee (0.128 g) was used to convert μg a.i./bee to a μg a.i./g (ppm) concentration and then compare 

this toxic level to concentrations expected on terrestrial invertebrates that are sprayed on directly. 

Thirty percent mortality was observed at 262 ug/bee in the contact thorax test (MRID 

42806407). So, the LD30 is equal to 262/0.128 = 2047 mg/kg. This is slightly below exposure 

(2538 ppm) at 27 lb/A. Mortality slightly exceeding 30% at maximum broadcast rate is 

expected, providing that individuals are thoroughly wetted. 

While honeybees were relatively insensitive to the insecticidal soap, it is reported that potassium 

salts are relatively selective in its toxicity to invertebrates based on the insect species and stage 

of development. Soft-bodied insects such as aphids, whiteflies, and mealy bugs are more 

susceptible to soaps. The least affected are flying adult insects with heavier cuticle, such as 

ladybird beetles; however, hard-bodied insects in the immature, flightless stage of development 

can be vulnerable to the effects of potassium salts.4

 Thus, not all terrestrial invertebrates were 

susceptible to soap salts but those that are soft-bodied including hard-bodied ones during larval 

development would be sensitive when exposed directly to potassium salt applications. 

Lastly, formulated as a contact insecticide, it is unlikely the adverse effect of the use patterns 

would be maintained beyond the target application area since potassium salts are effective only 

against those susceptible terrestrial invertebrates that come into direct contact; yet, without 

additional information on listed terrestrial invertebrates, it is uncertain whether all, some, or none 

of the listed invertebrates would be adversely affected when exposed directly to potassium salts. 

 IV.2.2.4 Risk to Terrestrial Plants 

The risk to non-target plants exposed to soap salts is unlikely because 1) TERRPLANT does not 

account for the rapid degradation of soap salts before or during surface water runoff following 

application; 2) As discussed above in the aquatic assessment, environmental fate and effect data 

indicate that soap salts products in water are either too insoluble to reach toxic concentrations or 

soluble enough but not toxic enough to cause adverse effects; 3) Terrestrial plant toxicity studies 

on seedling emergence and vegetative vigor resulted in adverse effects to the vigor of young 

plants when exposed to soap salts formulated products; this data support the assumption that 

vegetative vigor is a more sensitive life-stage than seedling emergence, when plants are 

adversely affected as a result of unwanted spray drift rather than surface water runoff to areas 

where non-target terrestrial plants inhabits; and 4) There were no LOC exceedances for plants 

exposed to unwanted spray drift alone. Thus, it is unlikely for soap salts products to maintain its 

 

4

 http://greenmethods.com/site/weblog/2009/05/understanding-insecticidal-soaps-and-detergents 
51 

toxicity in periodically wet areas where terrestrial plants resides after the pesticide runoff or drift 

away from the adjacent treated field. 

Based on the available data, monocots are less sensitive to soap salts than dicots. The RQs for 

runoff to semi-aquatic areas result in the highest RQs. This scenario represents a 10 acre area 

running off into a one acre area. The highest RQ for runoff to semi-aquatic areas was a 1.47, 

which barely exceeded the Agency’s LOC of 1 for potential risk to plants. On the other hand, 

none of the RQs for plants inhabiting dry areas exposed to a combination of runoff and drift and 

for plants inhabiting areas exposed to spray drift alone exceeded the Agency’s LOCs. Since the 

main route of exposure to non-target terrestrial plants is by spray drift, not by runoff, the LOC 

exceedance for potential risk to plants inhabiting semi-aquatic areas is discounted. 

For ammonium salts, none of the RQs exceeded the plant LOC of 1.0; risk to non-target plants 

exposed as a result of receiving surface water runoff and/or spray drift is expected to be low. 

Exposure to plants is based on the highest single application rate; multiple applications are not 

considered. The current assumption is that plants will be mainly affected by the first application. 

Although there is uncertainty in this assumption, there would also be uncertainty in trying to 

model multiple applications. Data the Agency receives for terrestrial plants is based on a single 

application, followed by a 14 to 21 day observation period. To estimate the effect of a second 

application would require a simplistic assumption of additive effect, when in fact the effect may 

be much more complex. 

The most sensitive plant in the Vegetative Vigor test (Table III.22) is tomato for an ammonium 

salt formulation. The EC25 is 2.2 lb/A and the EC05 is 1.1 lb/A. (Radish VV has NOAEC of 

0.094, but EC25 is higher, 5.8 lb/A.) On-site RQs are therefore 27/2.2 = 12.3 and 27/1.1 = 24.5, 

which are both above the LOC of 1.0. A spray drift analysis (AgDrift, Tier 1 hi-boom, finemedium/coarse spray, 90th percentile) gives a negligible buffer (13 feet) for a 1.1 lb/A threshold. 

Thus, spray drift-caused effects to terrestrial plants are expected to be limited to plants on the 

treated field. 

IV.2.2.5 Terrestrial Plants Exposed to Soap Salts As a Result of 

Spot Treatment Applications 

Similar to the aquatic risk assessment, EFED has modified the terrestrial plant risk assessment 

for spot treatment uses using an assumption that the high rates are broadcast (Table IV.15). As 

discussed above (Table IV.11) and in Table IV.15 below, if a site were only spot treated at less 

than 42% of the entire field at the maximum 205 lb a.i./A rate, the LOC would not be exceeded 

and no adverse effect determination for listed terrestrial plants would be likely for this use. 

 
52 

Table IV.15 Percentage of Exposure from Spray Drift Needed to Exceed the LOC 

Taxa Application 

rates 

(lb a.i./A) 

RQs (highest to 

lowest)* 

LOC Percentage of 

exposure needed 

to exceed LOC1

Potassium Salts 

 Terrestrial plants 

(non-listed effects) 

205 1.7 Non-listed = 1.0 59% 

116 0.98 No exceedance 

63 0.5 No exceedance 

Terrestrial plants 

(listed effects) 

205 2.4 

Listed = 1.0 

42% 

116 1.4 71% 

63 0.7 No exceedance 

Ammonium Salts

 Terrestrial plants 

(non-listed effects) 

205 2.4 Non-listed = 1.0 42% 

116 1.4 71% 

63 0.2 No exceedance 

Terrestrial plants 

(listed effects) 

205 4.7 

Listed = 1.0 

21% 

116 2.9 34% 

63 0.5 No exceedance 

*Bold values indicate LOC exceedance 

1 The threshold percentage is assessed to determine how much percent of exposure that RQ needs to exceed the 

LOC. For example, the highest listed RQ for terrestrial plants inhabiting an area adjacent to a field applied at 205 lb 

a.i./A potassium salts is 2.4 which is 2.4 times higher than the listed species LOC of 1.0; to assess the % of exposure 

needed at which the LOC exceedance occurred, results indicate 42% is needed for the RQ to exceed the LOC. A “no 

effect” or “may affect” determination was not made since it is unknown what % of an actual area is typical spot 

treatment. 

V. Federally Threatened and Endangered (Listed) Species Concerns 

In November 2013, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the 

National Marine Fisheries Service (NMFS) (collectively, the Services), and the U.S. Department 

of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks 

to listed species from pesticides. The Interim Approaches were developed jointly by the 

agencies in response to the National Academy of Sciences’ (NAS) recommendations and reflect 

a common approach to risk assessment shared by the agencies as a way of addressing scientific 

differences between the EPA and the Services. The NAS report outlines recommendations on 

specific scientific and technical issues related to the development of pesticide risk assessments 

that EPA and the Services must conduct in connection with their obligations under the 

Endangered Species Act (ESA) and FIFRA. 

The joint Interim Approaches were released prior to a stakeholder workshop held on 

November 15, 2013. In addition, the EPA presented the joint Interim Approaches at the 

December 2013 Pesticide Program Dialogue Committee (PPDC) and State-FIFRA Issues 

Research and Evaluation Group (SFIREG) meetings, and held a stakeholder workshop in April 

2014, allowing additional opportunities for stakeholders to comment on the Interim Approaches. 

As part of a phased, iterative process for developing the Interim Approaches, the agencies will 

also consider public comments on the Interim Approaches in connection with the development of 

upcoming Registration Review decisions. The details of the joint Interim Approaches are 
53 

contained in the white paper “Interim Approaches for National-Level Pesticide Endangered 

Species Act Assessments Based on the Recommendations of the National Academy of Sciences 

April 2013 Report,” dated November 1, 2013. 

 Given that the agencies are continuing to develop and work toward implementation of the 

Interim Approaches to assess the potential risks of pesticides to listed species and their 

designated critical habitat, this preliminary risk assessment for soap salts does not contain a 

complete ESA analysis that includes effects determinations for specific listed species or 

designated critical habitat. Although EPA has not yet completed effects determinations for 

specific species or habitats, for this preliminary assessment EPA conducted a screening-level 

assessment for all taxa of non-target wildlife and plants that assumes for the sake of the 

assessment that listed species and designated critical habitats may be present in the vicinity of 

the application of soap salts. This screening level assessment will allow EPA to focus its future 

evaluations on the types of species where the potential for effects exists once the scientific 

methods being developed by the agencies have been fully vetted. This screening-level risk 

assessment for soap salts indicates potential risks of direct effects to listed plants and terrestrial 

invertebrate, based on pesticidal claims, on some of the registered use sites. Listed taxa may also 

be affected through indirect effects because of the potential for direct effects on listed and nonlisted species upon which such species may rely. Potential direct effects on listed plants and 

terrestrial invertebrates from the use of soap salts may be associated with modification of 

Primary Constituent Elements (PCEs) of designated critical habitats, where such designations 

have been made. Once the agencies have fully developed and implemented the scientific 

methods necessary to complete risk assessments for endangered and threatened (listed) species 

and their designated critical habitats, these methods will be applied to subsequent analyses for 

soap salts as part of completing this registration review. 

V.1. Action Area 

For listed species assessment purposes, the action area is considered to be the area affected 

directly or indirectly by the registered use and not merely the immediate area where the pesticide 

is applied. At the initial baseline, the risk assessment considers broadly described taxonomic 

groups and conservatively assumes that listed species within those broad groups are co-located 

with the pesticide treatment area. This means that listed terrestrial plants and wildlife are 

assumed to be located on or adjacent to the treated site and listed aquatic organisms are assumed 

to be located in a surface water body adjacent to the treated site. The assessment also assumes 

that the listed species are located within an assumed area, which has the relatively highest 

potential exposure to the pesticide, and that exposures are likely to decrease with distance from 

the treatment area. Section III of this risk assessment presents the registered pesticide use sites 

that are used to establish initial co-location of species with treatment areas. 

The federal action addressed herein is the registration review of potassium, ammonium, and 

sodium salts of fatty acids on agricultural, residential, and commercial use sites. Based on the 

wide-ranging registered uses, it is expected that the action area is nationwide. 

V.2. Taxonomic Groups Potentially at Risk 

 
54 

If the assumptions associated with the baseline action area result in RQs that are below the listed 

species LOCs, a "no effect" determination conclusion is made with respect to listed species in 

that taxon, and no further refinement of the action area is necessary. Furthermore, RQs below 

the listed species LOCs for a given taxonomic group indicate no concern for indirect effects on 

listed species that depend upon the taxonomic group for which the RQ was calculated. However, 

in situations where the screening assumptions lead to RQs in excess of the listed species LOCs 

for a given taxonomic group, a potential for a "may affect" conclusion exists and may be 

associated with direct effects on listed species belonging to that taxonomic group or may extend 

to indirect effects upon listed species that depend upon that taxonomic group as a resource. In 

such cases, additional information on the biology of listed species, the locations of these species, 

and the locations of use sites are considered to determine the extent to which screening 

assumptions regarding an action area applies to a particular listed organism. These subsequent 

refinement steps will consider how this information would impact the action area for a particular 

listed organism and potentially include areas of exposure that are downwind and downstream of 

the pesticide use site. 

Assessment endpoints, exposure pathways, and the conceptual models addressing the registered 

uses, and the associated exposure and effects analyses conducted for the soap salts (e.g. 

potassium, ammonium, and sodium salts of fatty acids) screening-level ecological risk 

assessment are in Sections II to III. The assessment endpoints used in the ecological risk 

assessment include those defined operationally as reduced survival, growth and reproductive 

impairment for both aquatic and terrestrial animal species and survival and growth of aquatic and 

terrestrial plant species from both direct acute and chronic exposures. These assessment 

endpoints are intended to address the standard set forth in the Endangered Species Act requiring 

federal agencies to ensure that any action they authorize does not appreciably reduce the 

likelihood of both the survival and recovery of a listed species in the wild by reducing the 

reproduction, numbers, or distribution of the species. Risk estimates (RQs), integrating exposure 

and effects, are calculated for broad based taxonomic groups in the screening-level risk 

assessment presented in Section IV.

Both acute listed species and chronic risk LOCs are evaluated in the screening-level ecological 

risk assessment to identify direct and indirect effects to taxa of listed species. This section 

identifies direct effect concerns, by taxon, that are triggered by exceeding endangered LOCs in 

the risk assessment, with an evaluation of the potential probability of individual effects for 

exposures that may occur at the established listed species LOC. Data on exposure and effects 

collected under field and laboratory conditions are evaluated to make determinations on the 

predictive utility of the direct effect screening assessment findings to listed species 

V.2.1. Probit Dose-Response Analysis 

The Agency uses the probit dose-response relationship as a tool for providing additional 

information on the potential for acute direct effects to aquatic and terrestrial animals (USEPA, 

2004). As part of this evaluation, the acute RQ for listed species is presented in terms of the 

chance of an individual event (i.e., mortality or immobilization) should exposure at the EEC 

actually occur for a species with sensitivity to soap salts on par with the acute toxicity endpoint 

selected for RQ calculation. To accomplish this interpretation, the Agency uses the slope of the 
55 

dose-response relationship available from the toxicity study used to establish the acute toxicity 

measures of effect for each taxonomic group except plants and terrestrial invertebrates that is 

relevant to this assessment. The individual effects probability associated with the acute RQ is 

based on the mean estimate of the slope and an assumption of a probit dose-response 

relationship. In addition to a single effects probability estimate based on the mean, upper and 

lower estimates of the effects probability are also provided to account for variance in the slope, if 

available. Based on the available acute toxicity for soap salts, a summary of the probit doseresponse analysis is provided in Table V.3. If no dose response information is available to 

estimate a slope for this analysis, a default slope assumption of 4.5 (with lower and upper bounds 

of 2 to 9) (Urban and Cook, 1986) is used. 

Except for terrestrial invertebrates, no risk concerns were identified for soap salts; thus, the 

probability of an acute direct effect to listed species derived based on the highest calculated acute 

RQ was not calculated. While LOC exceedances were seen in terrestrial invertebrates, an 

uncertainty exists since a honeybee study was used as a surrogate that triggered the exceedances. 

It was not proper to find the probability of an acute direct effect to Listed terrestrial invertebrates 

when risks were identified and no significant mortality was observed in honeybees as high as 

100 μg/bee. 

Individual effect probabilities are calculated based on an Excel spreadsheet tool IECV1.1 

(Individual Effect Chance Model Version 1.1) developed by the U.S. EPA, OPP, Environmental 

Fate and Effects Division (June 22, 2004). The model allows for such calculations by entering 

the mean slope estimate (and the 95% confidence bounds of that estimate) as the slope parameter 

for the spreadsheet. The desired threshold for the probability of an individual effect is entered as 

the listed species LOC or the derived acute RQ. 

Table V.3. Summary of Soap Salts Probit Dose Response Analysis for Listed Species 

Taxa (study type) Acute Effect 

Slope (95% C.I.) 

Chance of Individual Effect 

at Listed Species LOC (95% 

C.I.) 

Chance of Individual Effect at 

Derived Acute RQ (95% C.I.) 

Bird oral dose No mortality observed Not calculated; no mortality 

observed 

Not calculated; no mortality 

observed

Bird dietary No mortality observed Not calculated; no mortality 

observed

Not calculated; no mortality 

observed

Mammal oral dose No mortality observed Not calculated; no mortality 

observed 

Not calculated; no mortality 

observed 

Freshwater fish 

Mortality 

Slope = 3.9 

(3 – 5)

1 in 5.13E+06 

(1 in 2.1E+4 to 1 in 2.58E+10)

Not calculated; no LOC 

exceedances 

Estuarine/marine 

fish No mortality observed Not calculated; no mortality 

observed 

Not calculated; no mortality 

observed 

Freshwater 

Invertebrates 

Immobilization 

Slope = 3.2 

(2 – 4) 

1 in 6.38E+04 

(1 in 216 to 1 in 1.03E+7) Not calculated; environmental 

fate and effects data suggest 

soap salts in water is not toxic 

to aquatic invertebrates. Estuarine/marine 

Invertebrates 

Mortality 

Default Slope = 4.5 

(2 – 9) 

1 in 4.18E+08 

(1 in 216 to 1 in 1.75E+31) 

As shown in Table V.3, the probability for acute direct effects (i.e., mortality) to individual 

listed fish (based on the most sensitive species, rainbow trout) at the Listed species LOC is 1 in 
56 

5,130,000 following one application at 205 lb a.i./A. This reflects a slope of 3.9. The chance of 

an individual effect for freshwater and estuarine/marine invertebrates, based on the daphnid and 

mysid, respectively, are 1 in 63,800 and 1 in 418,000,000. 

 V.2.2. Listed Species Occurrence Associated with Soap Salts Use 

The goal of the co-location analysis is determine whether sites of pesticide use are 

geographically associated with known locations of listed species [following the convention of the 

Services, the word ‘species’ in this assessment may apply to a ‘species’, ‘subspecies’, or an 

Evolutionary Significant Unit (ESU)]. At the screening level, this analysis is accomplished 

using the LOCATES database (version 2.10.3). The database uses location information for listed 

species at the county level and compares it to agricultural census data (from 2002) for crop 

production at the same county level of resolution. The product is a listing of Federally-listed 

species that are located in counties known to produce the crops upon which the pesticide will be 

used. 

Additional data is needed on the potentially affected species associated with the registered uses 

of soap salts; thus, until the uncertainties have been addressed, this analysis has not been 

conducted for this assessment. For the purposes of listed species effects determination, exposure 

is assumed to occur. 

VI. References 

Irani, R.R. and C.F. Callis (1960). Metal complexing by phosphorous compounds II. Solubility 

of calcium salts of linear carboxylic acids. J. Phys. Chem. 64:1741 

USEPA. 2004. Overview of the Ecological Risk Assessment Process in the Office of Pesticide 

Programs, U.S. Environmental Protection Agency. Endangered and Threatened Species 

Effects Determinations. Office of Prevention, Pesticides and Toxic Substances, Office of 

Pesticide Programs, Washington, D.C. January 23, 2004. Online at: 

http://www.epa.gov/oppfead1/endanger/consultation/ecorisk-overview.pdf 

USEPA. 2006b. User’s Guide: TerrPlant Version 1.2.2 (Terrestrial Residue Exposure model). 

 United States Environmental Protection Agency. Environmental Fate and Effects 

Division. Office of Pesticide Programs. U.S. Environmental protection Agency. 

Washington, D.C. December 26, 2006. 

Urban, D.J. and N.J. Cook, 1986. Hazard Evaluation Division Standard Evaluation Procedure 

Ecological Risk Assessment. EPA 540/9-85-001. U.S. Environmental Protection 

Agency, Office of Pesticide Programs, Washington D.C. 

VI.1. Submitted Studies 

Guideline: OPPTS 850.2100 Avian Single Dose Oral Toxicity 

------------------------------------------------------------------------------------- 

AMMONIUM 
57 

No studies available 

POTASSIUM 

MRID: 44980310 

W.M.M. Stadens-peek and Drs. M.A. Leopold. 1996. Acute Oral toxicity Study in Bobwhite Quail. Unpublished 

study performed by NOTOX,‘s-Hertogenbosch, Netherlands. Laboratory Study No. 185052. Sponsored by Neudorff 

GmbH KG, Emmerthal, Germany. Study completed December 20, 1996. 

MRID: 40066202 

Hinken C. & Jaber, M. 1987. Aphid-Mite Attack Concentrate: An Acute Oral Toxicity Study with the Bobwhite. 

Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 227-103A. 

Sponsored by Reuter Laboratories, Manassas Park, Virginia. Study completed January 16, 1987. 

MRID: 40053301 

Grimes, J. & Jaber, M. 1987. Aphid-Mite Attack Concentrate: An Acute Oral Toxicity Study with the Bobwhite. 

Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 227-103. 

Sponsored by Reuter Laboratories, Manassas Park, Virginia. Study completed December 29, 1986. 

MRID: 30861 

Hunsaker, D. 1979. Acute Oral Toxicity Study of Safer’s Insecticidal Soap on Mallard Ducks. Unpublished study 

performed by San Diego State University, San Diego, CA. Laboratory study no.: Not reported. Sponsored by SaferAgro Chem Ltd, Victoria, British Columbia. Study completed May 24, 1979. 

SODIUM 

No studies available 

Guideline: OPPTS 850.2300 Avian Dietary Toxicity 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 46206301 

Bien, E. 2003. Avian Dietary Toxicity Test of NEU 1170 H in the Japanese Quail. Unpublished study performed by 

Harlan Bioservice for Science GmbH, Walsrode, Germany. Laboratory Study No.: 10-16-0146-03. Sponsored by 

Neudorff GmbH KG, Emmerthal, Germany. Study completed October 30, 2003. 

POTASSIUM 

MRID: 00157472 

Beavers, J.B. 1986. Safer Herbicide H2: A Dietary LC50 Study with the Bobwhite. Unpublished study performed by 

Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 208-104. Sponsored by Safer Agro-Chem 

Ltd., British Columbia, Canada. Study completed January 31, 1986. 

MRID: 00105040 

Beavers, J.B. and R. Fink. 1981. Untitled. Final Report on the Toxicity of Safer’s Insecticidal Soap #1 to Mallard 

Duck (Anas platyrhynchos). Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. 

Laboratory Study No.: WI-447A. Sponsored by Applied Biological Sciences Laboratory, Glendale, California. 

Study completed May 5, 1981. 

MRID: 40385601 

Johnson, M. & Jaber, M. 1987. Herbicide H2: A Dietary LC50 Study with the Mallard. Unpublished study 

performed by Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 508-106. Sponsored by Safer 

Ltd., Victoria, British Columbia, Canada. Study completed August 7, 1987. 

MRID: 44980311 

Leopold, M.A. 1997. 5-day Dietary Toxicity Study in Bobwhite Quail. Unpublished study performed by NOTOX, 

‘s-Hertogenbosch, Netherlands. Laboratory Study Number 185085. Sponsored by W. Neudorff GmbH KG, 

Emmerthal, Germany. Study completed February 28, 1997. 
58 

MRID: 44980312 

Leopold, M.A. 1997. 5-day Dietary Toxicity Study in Mallard Duck. Unpublished study performed by NOTOX, ‘sHertogenbosch, Netherlands. Laboratory Study Number 185118. Sponsored by W. Neudorff GmbH KG, 

Emmerthal, Germany. Study completed March 3, 1997. 

MRID: 00096640 

Beavers, J.B. and R. Fink. 1981. Untitled. Final Report on the Toxicity of Safer’s Insecticidal Soap #1 to Bobwhite 

Quail (Colinus virginianus). Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. 

Laboratory Study No.: 157-107. Sponsored by Applied Biological Sciences Laboratory, Glendale, California. Study 

completed April 22, 1981. 

MRID: 40066203 

Grimes, J., Hinken, C., Jaber, M. 1987. Aphid-Mite Attack Concentrate: A Dietary LC50 Study with the Bobwhite. 

Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 227-101B. 

Sponsored by Reuter Laboratories, Manassas Park, Virginia. Study completed January 23, 1987. 

MRID: 40053302 

Grimes, J. & Jaber, M. 1986. Aphid-Mite Attack Concentrate: A Dietary Toxicity Study with the Bobwhite. 

Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 227-101A. 

Sponsored by Reuter Laboratories, Manassas Park, Virginia. Study completed December 12, 1986. 

MRID: 40053303 

Grimes, J. & Jaber, M. 1986. Aphid-Mite Attack Concentrate: A Dietary Toxicity Study with the Mallard. 

Unpublished study performed by Wildlife International, Ltd., Easton, Maryland. Laboratory Study No.: 227-102. 

Sponsored by Reuter Laboratories, Manassas Park, Virginia. Study completed November 7, 1986. 

MRID: 30862 

Condrashoff, S.F. 1979. Avian Dietary LC50 Toxicity of Safer’s Insecticidal Soap on the Mallard Duck. 

Unpublished study performed by Professional Ecological Services, Victoria, British Columbia. Laboratory Study 

No.: Not reported. Sponsored by Safer Agro-Chem Ltd, Victoria, British Columbia. Study completed October, 1979. 

MRID: 30863 

Condrashoff, S.F. 1979. Avian Dietary LC50 Toxicity of Safer’s Insecticidal Soap on the Bobwhite Quail. 

Unpublished study performed by Professional Ecological Services, Victoria, British Columbia. Laboratory Study 

No.: Not reported. Sponsored by Safer Agro-Chem Ltd, Victoria, British Columbia. Study completed November, 

1979. 

SODIUM 

No study available 

Guideline OPPTS 850.2300 Avian Reproduction 

------------------------------------------------------------------------------------- 

AMMONIUM 

No study available 

POTASSIUM 

No study available 

SODIUM 

No study available 

Guideline OPPTS 850.1075 Freshwater Fish Acute Toxicity 

----------------------------------------------------------------------------------------------- 
59 

AMMONIUM 

MRID: 42806405 

Ward, T.J., P.L. Kowalski, and R.L. Boari. 1993. Acute Toxicity of Hinder to the Rainbow Trout, Oncorhynchus 

mykiss. Unpublished study performed by T.R. Wilbury Laboratories, Inc., Marblehead, Massachusetts. Laboratory 

Study No.: 211-UN. Sponsored by Uniroyal Chemical Company, Inc., Bethany, Connecticut. Study completed on 

May 28, 1993. 

POTASSIUM 

MRID: 00096636 

Berlin, C. 1981. Static Acute Toxicity – Fish Bioassay with Rainbow Trout. Unpublished study performed by 

Applied Biological Sciences Laboratory, Glendale, California. Laboratory Study Number 17382. Sponsored by 

Safer Agro, British Columbia, Canada. Study completed June 12, 1981. 

MRID: 00090936 

Janssen, R. 1979. Acute Toxicity Study of Safer’s Insecticidal Soap on the Rainbow Trout (Salmo gairdneri). 

Unpublished study performed by E.V.S. Consultants Ltd, Victoria, British Columbia. Laboratory Study Number 

791/79-23. Sponsored by Safer Agro-Chem Ltd., Richmond, British Columbia, Canada. Study completed April, 

1979. 

MRID: 44980314 

Grunert, B. 1996. Acute Toxicity Study in Bluegill Sunfish. Unpublished study performed by NOTOX, ‘sHertogenbosch, Netherlands. Laboratory study number 185142. Sponsored by W. Neudorff GmbH KG, Emmerthal, 

Germany. Study completed August 1, 1996. 

MRID: 44980313 

Nedvidek, W. 1996. Acute Toxicity Study in Rainbow Trout with Neudosan Neu. Unpublished study performed by 

BioChem GmbH, Karlsruhe, Germany. Laboratory study no.: 96 50 41 213 A. Sponsored by W. Neudorff GmbH 

KG, Emmerthal, Germany. Study completed July 30, 1996. 

MRID: 40053304 

Obenchain, F. 1986. Salmo gairdneri– Acute Toxicity Tests on Aphid-Mite Attack. Unpublished study performed by 

EA Engineering, Science, and Technology, Inc., Sparks, Maryland. Laboratory study no.: 12-19-133. Sponsored by 

Reuter Laboratories, Inc., Manassas Park, Virginia. Study completed December 1986. 

MRID: 40053304 

Obenchain, F. 1986. Lepomis macrochirus – Acute Toxicity Tests on Aphid-Mite Attack. Unpublished study 

performed by EA Engineering, Science, and Technology, Inc., Sparks, Maryland. Laboratory study no.: 12-19-133. 

Sponsored by Reuter Laboratories, Inc., Manassas Park, Virginia. Study completed December 1986. 

MRID: 909737 

Reid, B. 1979. Acute Toxicity of Safer’s Insecticidal Soap on Goldfish. Unpublished study performed by E.V.S. 

Consultants Ltd., North Vancouver, British Columbia. Laboratory study no.: 791. Sponsored by Safer Agro-Chem 

Ltd., Victoria, British Columbia. Study completed November, 1979. 

SODIUM 

No study available 

Guideline OPPTS 850.1075 Estuarine/marine Fish Acute Toxicity 

----------------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 48402202 

Fournier, A.E. 2011. H01 Concentrate Herbicidal Soap - Acute Toxicity to Sheepshead Minnow (Cyprinodon 

variegates) Under Static-Renewal Conditions, Following OPPTS Draft Guideline 850.1075. Unpublished study 

performed by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No: 13989.6106. Sponsored by W. 
60 

Neudorff GmbH KG, Great Falls, Virginia. Study completed February 15, 2011. 

POTASSIUM 

MRID: 48469802 

Fournier, A.E. 2011. Neudorff’s Insecticidal Soap Concentrate - Acute Toxicity to Sheepshead Minnow 

(Cyprinodon variegates) Under Flow Through Conditions, Following OPPTS Draft Guideline 850.1075. 

Unpublished study performed by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No: 13989.6115. 

Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. Study completed April 26, 2011. 

MRID: 48636502 

Sayers, L.E. 2011. Safer Brand O-Insecticidal Soap Concentrate – Acute Toxicity to Sheepshead Minnow 

(Cyprinodon variegates) Under Flow-Through Conditions, Following OPPTS Draft Guideline 850.1075. Laboratory 

Study No.: 13999.6107. Sponsored by Soap Salts Reregistration Task Force, Washington, DC. Study completed 

October 4, 2011. 

SODIUM 

No study available 

Guideline OPPTS 850.1010 Freshwater Invertebrate Acute Toxicity 

--------------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 42806406 

Ward, T.J., Kowalski, P.L., and R.L. Boeri. 1993. Acute Toxicity of Hinder to the Daphnid, Daphnia magna. 

Unpublished study performed by T.R. Wilbury Laboratories, Inc., Marblehead, Massachusetts. Laboratory study no: 

210-UN. Sponsored by Uniroyal Chemical Company, Inc., Bethany Connecticut. Study completed May 28, 1993 

and amended June 2, 1993. 

MRID: 44760402 

Kleiner, R. 1998. Acute Immobilization Test Daphnia – Daphnia magna according to OECD Guideline 202-1 

(1984) NEU 1170 H (22%). Unpublished study performed by BioChem Agrar, Labor fur biologische und chemische 

Analytik, Cunnersdorf, Germany. Laboratory study no.: 98 10 78 039. Sponsored by Neudorff GmbH KG, 

Emmerthal, Germany. Study completed July 8, 1998 and amended September 24, 1998. Addendum No. 1 was 

completed September 22, 1998. 

POTASSIUM 

MRID: 44980315 

Grunert, B. 1996. Acute Daphnia Immobilization Test with Neudosan Neu. Unpublished study performed by 

BIOCHEM, Karlsruhe, Germany. Laboratory study number 96 50 41 213 B. Sponsored by Neudorff GmbH KG, 

Emmerthal, Germany. Study completed August 1, 1996 and amended August 22, 1997. 

MRID: 40053305 

Harrison, E. 1986. Aphid-Mite Attack Concentrate 48-hour Static Acute Bioassay: Daphnid pulex. Unpublished 

study performed by James R. Reed and Associates, Inc., Newport News, Virginia. Laboratory study number 86-

3368. Sponsored by Reuter Laboratories, Inc., Manassas Park, Virginia. Study completed November 15, 1986. 

MRID: 30865 (96638) 

Condrashoft, S.F.. 1979. Acute Toxicity LC50 of Safer’s Insecticidal Soap on Daphnid pulex. Unpublished study 

performed by Professional Ecological Services, Victoria, British Columbia. Laboratory study number not reported. 

Sponsored by Safer’s Agro-Chem Ltd., Victoria, British Columbia. Study completed July, 1979. 

SODIUM 

No study available 

Guideline OPPTS 850.1025 Estuarine/Marine Mollusk Acute Toxicity (Shell Deposition) 
61 

------------------------------------------------------------------------------------- 

AMMONIUM 

No study available 

POTASSIUM 

No study available 

SODIUM 

No study available 

Guideline OPPTS 850.1035 Estuarine/Marine Invertebrate Acute Toxicity 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 48402201 

A. E. Fournier. 2011. H01 Concentrate Herbicidal Soap -Acute Toxicity to Mysid (Americamysis bahia) Under 

Static-Renewal Conditions, Following OPPTS Guideline 850.1035. Unpublished study performed by Smithers 

Viscient, Wareham, Massachusetts. Laboratory Study No. 13989.6105. Study sponsored by W. Neudorff GmbH 

KG, Great Falls, Virginia. Study completed February 15, 2011. 

POTASSIUM 

MRID: 48469801 

A. E. Fournier. 2011. Neudorff’s Insecticidal Soap Concentrate -Acute Toxicity to Mysid (Americamysis bahia) 

Under Flow Through Conditions, Following OPPTS Guideline 850.1035. Unpublished study performed by Smithers 

Viscient, Wareham, Massachusetts. Laboratory Study No. 13989.6114. Study sponsored by W. Neudorff GmbH 

KG, Great Falls, Virginia. Study completed April 22, 2011. 

MRID: 48608707 

Sayers, L.E. 2011. Safer Brand O-Insecticidal Soap Concentrate -Acute Toxicity to Mysid (Americamysis bahia), 

Under Flow Through Conditions, Following OPPTS Guideline 850.1035. Unpublished study performed by Smithers 

Viscient, Wareham, Massachusetts. Laboratory Study No. 13999.6106. Study sponsored by Smithers Viscient, 

Wareham, Massachusetts. Study completed September 20, 2011. 

SODIUM 

No study available 

Guideline OPPTS 850.1300 Freshwater Aquatic Invertebrate Life Cycle 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 48402203 

Fournier, A.E. 2011. H01 Concentrate Herbicidal Soap – Full Life-Cycle Toxicity Test with Water Fleas (Daphnia 

magna) Under Static-Renewal Conditioning, Following OPPTS Draft Guideline 850.1300. Unpublished study 

performed by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No.: 13989.6107. Sponsored by W. 

Neudorff GmbH KG, Great Falls, Virginia. Study completed February 24, 2011. 

POTASSIUM 

MRID: 48668601 

Fournier, A.E. 2011. Neudorff’s Insecticidal Soap Concentrate – Full Life-Cycle Toxicity Test with Water Fleas 

(Daphnia magna) Under Flow-Through Conditions, Following OPPTS Draft Guideline 850.1300. Unpublished 

study performed by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No.: 13989.6116. Sponsored by 

W. Neudorff GmbH KG, Great Falls, Virginia. Study completed November 23, 2011. 

MRID: 48664201 

Sayers, L.E. 2011. Safer Brand O-Insecticidal Soap Concentrate – Full Life-Cycle Toxicity Test with Water Fleas 
62 

(Daphnia magna) Under Flow-Through Conditions, Following OPPTS Draft Guideline 850.1300. Unpublished 

study performed by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No.: 13999.6108. Sponsored by 

Soap Salts Reregistration Task Force, Washington, DC. Study completed November 18, 2011. 

SODIUM 

No study available 

Guideline OPPTS 850.1350 Estuarine/Marine Invertebrate Life Cycle 

------------------------------------------------------------------------------------- 

AMMONIUM 

No study available 

POTASSIUM 

No study available 

SODIUM 

No study available 

Guideline OPPTS 850.1400 Freshwater and Estuarine/marine Fish Early-Life Stage 

------------------------------------------------------------------------------------- 

AMMONIUM 

No study available 

POTASSIUM 

No study available 

SODIUM 

No study available 

Guideline OPPTS 850.3020 Honeybee Acute Contact Toxicity 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 44766401 

Nengel, S. 1998. Assessment of Side Effects of NEU 1170 H to the Honey Bee, Apis mellifera L. in the Laboratory 

Following EPPO Guideline No. 170. Unpublished study performed by Arbeitsgemeinschaft, GAB Biotechnologie 

GmbH & IFU Umweltanalytik GmbH, Niefern-Oschelbronn, Germany. Laboratory Study No.: 97253/01-BLEU. 

Sponsored by Neudorff GmbH KG, Emmerthal, Germany. Study completed June 22, 1998. 

MRID: 42806407 

Ward, T.J., Kowalski, P.L., and Boari, R.L. 1993. Acute Toxicity of Hinder to the Honey Bee, Apis mellifera. 

Unpublished study performed by T.R. Wilbury Laboratories, Inc., Marblehead, Massachusetts. Laboratory Study 

No.: 209-UN. Sponsored by Uniroyal Chemical Company, Inc., Bethany, Connecticut. Study completed May 28, 

1993. 

POTASSIUM 

MRID: 42806001 

Hoxter, K.A., Bernard, W.L., and Smith, G.J. 1993. Ringer/Safer 50% Insecticidal Soap Concentrate Technical 

grade: An Acute Contact toxicity Study with the Honey Bee. Unpublished study performed by Wildlife International 

Ltd., Easton, Maryland. Laboratory Study No.: 333-101D. Sponsored by Ringer Corporation, Eden Prairie, 

Minnesota. Study completed on May 12, 1993. 

SODIUM 

No study available 
63 

Guideline OPPTS 850.4100 Seedling Emergence 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 48402204 

Martin, J.A. 2011. H01 Concentrate Herbicidal Soap – Seedling Emergence Test Following U.S. EPA OPPTS Draft 

Guideline 850.4225. Unpublished study performed by Smithers Viscient, Wareham, Massachusetts. Laboratory 

Study Number 13989.6101. Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. Study completed February 

18, 2011. 

POTASSIUM 

MRID: 48608704 

Martin, J.A. 2011. Safer Brand O-Insecticidal Soap Concentrate – Seedling Emergence Test Following U.S. EPA 

OPPTS Draft Guidelines 850.4100 and 850.4225. Unpublished study performed by Smithers Viscient, Wareham, 

Massachusetts. Laboratory Study Number 13999.6102. Sponsored by Soap Salts Reregistration Task Force, 

Washington, DC. Study completed September 13, 2011. 

MRID: 48402301 

Martin, J.A. 2011. Neudorff’s Insecticidal Soap Concentrate – Seedling Emergence Test Following U.S. EPA 

OPPTS Draft Guideline 850.4225. Unpublished study performed by Smithers Viscient, Wareham, Massachusetts. 

Laboratory Study Number 13989.6110. Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. Study 

completed February 18, 2011. 

SODIUM 

No study available 

Guideline OPPTS 850.4150 Vegetative Vigor 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 48402205 

Martin, J.A. 2011. H01 Concentrate Herbicidal Soap – Vegetative Vigor Test Following U.S. EPA OPPTS Draft 

Guideline 850.4250 (Tier II). Unpublished study performed by Smithers Viscient, Wareham, Massachusetts. 

Laboratory Study Number 13989.6102. Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. Study 

completed February 15, 2011. 

POTASSIUM 

MRID: 48608703 

Martin, J.A. 2011. Safer Brand O-Insecticidal Soap Concentrate – Vegetative Vigor Test Following U.S. EPA 

OPPTS Draft Guideline 850.4250 (Tier II). Unpublished study performed by Smithers Viscient, Wareham, 

Massachusetts. Laboratory Study No. 13999.6103. Sponsored by Soap Salts Reregistration Task Force, Washington, 

DC. Study completed September 14, 2011. 

MRID: 48402302 

Martin, J.A. 2011. Neudorff’s Insecticidal Soap Concentrate – Vegetative Vigor Test Following U.S. EPA OPPTS 

Draft Guideline 850.4225 (Tier II). Unpublished study performed by Smithers Viscient, Wareham, Massachusetts. 

Laboratory Study No.: 13989.6111. Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. Study completed 

February 15, 2011. 

SODIUM 

No studies available 

Guideline OPPTS 850.4400 Aquatic Vascular Plant Toxicity 

------------------------------------------------------------------------------------- 
64 

AMMONIUM 

MRID: 48402206 

Softcheck, K.A. 2011. H01 Concentrate Herbicidal Soap – 7-day toxicity Test with Duckweed (Lemna gibba)

following OPPTS Draft Guideline 850.4400. Unpublished study performed by Smithers Viscient, Wareham, 

Massachusetts. Laboratory Study No.13989.6103. Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. 

Study completed on February 17, 2011. 

POTASSIUM 

MRID: 48608702 

Softcheck, K.A. 2011. Safer Brand O-Insecticidal Soap Concentrate – 7-day Toxicity Test with Duckweed (Lemna 

gibba) following OPPTS Draft Guideline 850.4400. Unpublished study performed by Smithers Viscient, Wareham, 

Massachusetts. Laboratory Study No. 13999.6104. Sponsored by Soap Salts Reregistration Task Force, Washington, 

DC. Study completed September 16, 2011. 

MRID: 48469803 

Softcheck, K.A. 2011. Neudorff’s Insecticidal Soap Concentrate – 7-day Toxicity Test with Duckweed (Lemna 

gibba) following OPPTS Draft Guideline 850.4400. Unpublished study performed by Smithers Viscient, Wareham, 

Massachusetts. Laboratory Study No. 13989.6112. Sponsored by W. Neudorff GmbH KG, Great Falls, Virginia. 

Study completed April 15, 2011. 

SODIUM 

No study available 

Guideline OPPTS 850.5400 Algal Plant Toxicity 

------------------------------------------------------------------------------------- 

AMMONIUM 

MRID: 48402207 

Softcheck, K.A. 2011. H01 Concentrate Herbicidal Soap – 96-hour Toxicity Test with the Freshwater Green Alga, 

Pseudokirchneriella subcapitata, Following OPPTS Draft Guideline 850.4400. Unpublished study performed by 

Smithers Viscient, Wareham, Massachusetts. Laboratory Study No. 13989.6104. Sponsored by W. Neudorff GmbH 

KG, Great Falls, Virginia. Study completed February 22, 2011. 

POTASSIUM 

MRID: 48608701 

Softcheck, K.A. 2011. Safer Brand O-Insecticidal Soap Concentrate – 96-hr Toxicity Test with the Freshwater 

Diatom, Navicula pelliculosa. Unpublished study performed by Smithers Viscient, Wareham, Massachusetts. Study 

No. 13999.6111. Sponsored by Soap Salts Reregistration Task Force, Washington, DC. Study completed September 

16, 2011. 

MRID: 48636501 

Softcheck, K.A. 2010. Safer Brand O-Insecticidal Soap Concentrate – 96-hr Toxicity Test with the Freshwater BlueGreen Alga, Anabaena flos aquae, Following OPPTS Draft Guideline 850.5400. Unpublished study performed by 

Smithers Viscient, Wareham, Massachusetts. Laboratory Study No. 13999.6110. Sponsored by Soap Salts 

Reregistration Task Force, Washington, DC. Study completed September 30, 2011. 

MRID: 48608706 

Softcheck, K.A. 2010. Safer Brand O-Insecticidal Soap Concentrate – 96-hr Toxicity Test with the Freshwater 

Green Alga, Pseudokirchneriella subcapitata, Following OPPTS Draft Guideline 850.5400. Unpublished study 

performed by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No. 13999.6105. Sponsored by Soap 

Salts Reregistration Task Force, Washington, DC. Study completed September 15, 2011. 

MRID: 48402303 

Softcheck, K.A. 2010. Neudorff’s Insecticidal Soap Concentrate – 96-hr Toxicity Test with the Freshwater Green 

Alga, Pseudokirchneriella subcapitata, Following OPPTS Draft Guideline 850.5400. Unpublished study performed 
65 

by Smithers Viscient, Wareham, Massachusetts. Laboratory Study No. 13989.6113. Sponsored by W. Neudorff 

GmbH KG, Great Falls, Virginia. Study completed February 24, 2011. 

MRID: 48608705 

Softcheck, K.A. 2011. Safer Brand O-Insecticidal Soap Concentrate – 96-hr Toxicity Test with the Marine Diatom, 

Skeletonema costatum, Following OPPTS Draft Guideline 850.5400. Unpublished study performed by Smithers 

Viscient, Wareham, Massachusetts. Laboratory Study No.: 13999.6109. Sponsored by Soap Salts Reregistration 

Task Force, Washington, DC. Study completed September 15, 2011. 

SODIUM 

No study available 
66 

Appendix A. GENEEC2 Inputs and Outputs 

 RUN No. 1 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

205.000(205.000) 1 1 100.0 100.0 AERL_B( 13.0) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 3.17 2.52 .89 .32 .21 

 RUN No. 2 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

116.000(116.000) 1 1 100.0 100.0 AERL_B( 13.0) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 1.79 1.43 .50 .18 .12 

 RUN No. 3 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

103.800(103.800) 1 1 100.0 100.0 AERL_B( 13.0) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 
67 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 1.60 1.28 .45 .16 .11 

 RUN No. 4 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

 63.000( 63.000) 1 1 100.0 100.0 AERL_B( 13.0) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 973.47 775.90 273.81 97.62 65.08 

 RUN No. 5 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

 10.000( 10.000) 1 1 100.0 100.0 AERL_B( 13.0) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 154.52 123.16 43.46 15.49 10.33 

 RUN No. 6 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

 1.000( 1.000) 1 1 100.0 100.0 AERL_B( 13.0) .0 .0 
68 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 15.45 12.32 4.35 1.55 1.03 

 RUN No. 7 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

205.000(205.000) 1 1 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 2.85 2.24 .79 .28 .19 

 RUN No. 8 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

116.000(116.000) 1 1 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 1.61 1.27 .45 .16 .11 

 RUN No. 9 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 
69 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

103.800(103.800) 1 1 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 1.44 1.13 .40 .14 .09 

 RUN No. 10 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

 63.000( 63.000) 1 1 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 876.40 687.46 241.76 86.18 57.46 

 

 RUN No. 11 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

 10.000( 10.000) 1 1 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 
70 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 139.11 109.12 38.37 13.68 9.12 

 RUN No. 12 FOR soap salts ON any * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

 1.000( 1.000) 1 1 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MICROGRAMS/LITER (PPB)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 13.91 10.91 3.84 1.37 .91 

EECs after 3, 10, 25, and 50 applications at the maximum rate 

 RUN No. 3 FOR soap salts ON * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

205.000(206.614) 3 7 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 3.01 2.38 .84 .30 .20 

 RUN No. 10 FOR soap salts ON * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

205.000(206.614) 10 7 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 
71 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 3.02 2.39 .84 .30 .20 

 RUN No. 25 FOR soap salts ON * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

205.000(206.614) 25 7 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 3.02 2.39 .84 .30 .20 

 RUN No. 50 FOR soap salts ON * INPUT VALUES * 

 -------------------------------------------------------------------- 

 RATE (#/AC) No.APPS & SOIL SOLUBIL APPL TYPE NO-SPRAY INCORP 

 ONE(MULT) INTERVAL Koc (PPM ) (%DRIFT) (FT) (IN) 

 -------------------------------------------------------------------- 

205.000(206.614) 50 7 100.0 100.0 GRHIFI( 6.6) .0 .0 

 FIELD AND STANDARD POND HALFLIFE VALUES (DAYS) 

 -------------------------------------------------------------------- 

 METABOLIC DAYS UNTIL HYDROLYSIS PHOTOLYSIS METABOLIC COMBINED 

 (FIELD) RAIN/RUNOFF (POND) (POND-EFF) (POND) (POND) 

 -------------------------------------------------------------------- 

 1.00 2 N/A .00- .00 2.00 2.00 

 GENERIC EECs (IN MILLIGRAMS/LITER (PPM)) Version 2.0 Aug 1, 2001 

 -------------------------------------------------------------------- 

 PEAK MAX 4 DAY MAX 21 DAY MAX 60 DAY MAX 90 DAY 

 GEEC AVG GEEC AVG GEEC AVG GEEC AVG GEEC 

 -------------------------------------------------------------------- 

 3.02 2.39 .84 .30 .20
72 

Appendix B. Incident Reports EIIS Pesticide Summary Report: Species Information

Potassium salts of fatty acids (079021)

Incident # Species Scientific Name Magnitude Response 

PLANTS

Cherry

I008521-001

cherry Prunus sp. 6 acres plant damage 

I008521-002

cherry Prunus sp. all .5 acres plant damage 

 Incident # Date County State Certainty Legal. Formul. Appl. Method PLANTS

Cherry

I008521-002 6/18/1998 YAKIMA WA 3 RU N/R Broadcast I008521-001 3/9/1999 YAKIMA WA 3 RU N/R Broadcast 
73 

APPENDIX C. Toxicity Study Summaries 

Freshwater Fish, Acute Effects 

Fish toxicity studies using the typical end-use products were submitted to establish the acute 

toxicity of salts to fish. Results of the acute studies with the ammonium and potassium salts 

formulated products to freshwater fish indicate the trout LC50 value of 12 mg a.i./L and 9.19 m

a.i./L, respectively, (Table C.1) are used to evaluate potential acute effects of the salts to 

freshwater fish. 

AMMONIUM SALTS OF FATTY ACIDS 

A 96h static-renewal acute exposure study (MRID 42806405; Supplemental) with rainbow tro

(Onchorhynchus mykiss) is available for a 13.1% ammonium salts of fatty acids formulation. 

Twenty trout per level were exposed to nominal concentrations of 0 (control), 3, 5, 8, 13 and 2

Table C.1. Freshwater Fish Acute Toxicity with Soap Salts (Ammonium and Potassium).

Species % a.i. 96-hour LC50

(mg a.i./L) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classificatio

AMMONIUM SALTS OF FATTY ACIDS 

Rainbow trout 

(Oncorhynchus mykiss) 13.1 12A Slightly 

toxic 

42806405 

Ward et al. (1993) Supplementa

POTASSIUM SALTS OF FATTY ACIDS 

Rainbow trout 

(Oncorhynchus mykiss) 

51 131.3B Practically 

nontoxic 

00090936 

Janssen. (1979) Supplementa

49 17C Slightly 

toxic 

44980313 

Nedvidek. (1996) Acceptable

25 9.19D Moderately 

toxic 

40053304 

Obenchain. (1986) Supplementa

Not 

reported

18.1 mg 

formulation/LE N/A4 00096636 

Berlin. (1981) Supplementa

Bluegill sunfish 

(Lepomis macrochirus) 25 23F Slightly 

toxic 

40053304 

Obenchain. (1986) Supplementa

A Trout 95% Confidence Interval (C.I.) = 11-14 mg a.i./L; slope = N/A (moving average) B Trout 95% C.I. = 85-151 mg a.i./L; slope = N/A (binomial) 

C Trout 95% C.I. = 7.67-28.64 mg a.i./L; slope = N/A (binomial) 

D Trout 95% C.I. = 7.28-11.5 mg a.i./L; slope (95% C.I) = 3.88 (2.53-5.22) 

E Trout 95% C.I. = 16.8-19.3 mg formulation/L; slope (95% C.I.) = 18.15 (9.42-26.88) 

F Sunfish 95% C.I. = 19.2-27.5 mg a.i./L; slope (95% C.I.) = 4.97 (3.27-6.66) 

1

 No chemical analyses were performed on the test concentrations at the beginning and end of the test as well as 

before and after each renewal. 

2

 Each concentration was less than 60% of the next higher concentration, there were not enough concentrations at 

which between 0% and 100% of the fish died in 96 hours. 

3

 Aeration was applied within 24 hours of the test in order to maintain dissolved oxygen levels since levels fell 

below 40% saturation between 24- and 48-hours. 

4

 The purity of the active ingredient in the formulation was not reported, it was not possible to determine the 

toxicity category for the active ingredient when corrected for purity. 5

 No chemical analyses of the test solutions for the presence of the formulation or active ingredient. 6

Aeration was used. 
74 

mg a.i./L (corrected for purity). 10, 40 and 100% mortalities occurred at the 8, 13 and 20 mg 

a.i./L concentrations. The LC50 was determined to be 12 mg a.i./L (adjusted for purity). Dark 

coloration and lethargy were observed in the 13 and 20 mg a.i./L concentrations, the EC50 could 

not be calculated; the visual-observed NOAEC is 8 mg a.i./L. 

POTASSIUM SALTS OF FATTY ACIDS 

A 96h static acute exposure study (MRID 90936; Supplemental) with rainbow trout 

(Onchorhynchus mykiss) is available for a 51% potassium salts of fatty acids formulation. Ten 

trout per level were exposed to nominal concentrations of 0 (control), 24, 43, 77, 135 and 240 

mg a.i./L (corrected for purity). No mortality occurred in the control or in concentrations up to 

43 mg a.i./L. 100% mortality occurred in the 135 mg a.i./L and 240 mg a.i./L, the two highest 

concentrations tested. While the formulated product was used, the 96-hour LC50 and NOAEC for 

the active ingredient was determined to be 131 and 87 mg a.i./L, respectively. 

A 96h static acute exposure study (MRID 96636; Supplemental) with rainbow trout 

(Onchorhynchus mykiss) is available for a potassium salts of fatty acids formulation. Twenty 

trout per level were exposed to nominal concentrations of 0 (control), 10, 15, 17, 20 and 22 mg 

formulation/L. The purity of the active ingredient was not reported; the reviewer could not 

correct the concentrations for purity. 10, 30, 70 and 100% mortalities occurred at the 15, 17, 20 

and 22 mg formulation/L concentrations. The LC50 was determined to be 18 mg formulation/L. 

Data on sub-lethal effects were not available to evaluate whether there were other effects than 

mortality. The statistical output calculated an NOAEC of 17 mg/L for mortality; however, the 

reviewer felt that the observed mortality at this level (30%) was biologically significant and 

therefore, visually determined the NOAEC to be 15 mg formulation/L based on the single 

mortality at this level. 

A 96h static acute exposure study (MRID 40053304; Supplemental) with bluegill sunfish 

(Lepomis macrochirus) is available for a 25% potassium salts of fatty acids formulation. Twenty 

sunfish per level were exposed to nominal concentrations of 0 (control), 10, 18, 32, 56 and 100 

mg a.i./L. 5, 30, 70, 100 and 100% mortalities occurred at the 10, 18, 32, 56 and 100 mg a.i./L 

test levels. While the formulated product was used, the 96-hour LC50 for the active ingredient 

based on 25% of product by volume was determined to be 23 mg a.i./L. 

A 96h static acute exposure study (MRID 40053304; Supplemental) with rainbow trout 

(Onchorhynchus mykiss) is available for a 25% potassium salts of fatty acids formulation. 

Twenty trout per level were exposed to nominal concentrations of 0 (control), 3.7, 7.5, 15.2, 32 

and 65 mg a.i./L. 10, 30, 80, 100 and 100% mortalities occurred at the 3.7, 7.5, 15.2, 32 and 65 

mg a.i./L test levels. While the formulated product was used, the 96-hour LC50 for the active 

ingredient based on 25% of product by volume was determined to be 9.19 mg a.i./L. 

A 96h static acute exposure study (MRID 44980313; Acceptable) with rainbow trout 

(Onchorhynchus mykiss) is available for a 49% potassium salts of fatty acids formulation. 

Twenty trout per level were exposed to initial-measured concentrations of 0 (control), 4.48, 7.67, 

28.64, 41.42, 260.1 and 404.9 mg a.i./L (adjusted for purity). 90, 100, 100 and 100% mortalities 

occurred at the 28.64, 41.42, 260.1 and 404.9 mg a.i./L test levels. The LC50 was determined to 

be 17 mg a.i./L. The NOAEC, based on sublethal effects of lying at the bottom, floating 

vertically and swimming slowly, is 4.48 mg a.i./L based on initial-measured concentrations. 
75 

Freshwater Fish, Chronic Effects 

AMMONIUM and POTASSIUM SALTS OF FATTY ACIDS 

No chronic ecological effects studies of ammonium and potassium salts using freshwater fish 

were submitted. 

Freshwater Invertebrates, Acute Effects 

Toxicity studies using the typical end-use products were submitted to establish the acute toxicity 

of salts to freshwater invertebrates. Results of the acute studies with the ammonium and 

potassium salts formulated products to freshwater invertebrates indicate the EC50 value of 27.1 

mg a.i./L and 0.57 mg a.i./L, respectively, (Table C.2) is used to evaluate potential acute effects 

of the salts to freshwater invertebrates. 

Table C.2. Freshwater Invertebrate Acute Toxicity with Soap Salts (Ammonium and 

Potassium). 

Species % a.i. 48-hour 

EC50 (mg 

a.i./L)

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Water flea 

(Daphnia magna)

13.1 27.1 A Slightly 

toxic 

42806406 

Ward et al. (1993) Supplemental1

22 30.9 B Slightly 

toxic 

44760402 

Kleiner (1998) Acceptable 

POTASSIUM SALTS OF FATTY ACIDS

Water flea 

(Daphnia pulex)

51 106 C Practically 

non-toxic 

00096638 

Condrashoft. 

(1979) 

Supplemental2

Water flea 

(Daphnia magna) 25 0.57 D Highly 

toxic 

40053305 

Harrison. (1986) Acceptable 

Water flea 

(Daphnia magna) 49 17.3 E Slightly 

toxic 

44980315 

Grunert. (1996) Supplemental1

A D. magna 95% Confidence Interval = 20-33 mg a.i./L; slope = N/A (binomial) 

B D. magna 95% Confidence Interval = 24-40.9 mg a.i./L; slope = N/A (moving average) 

C D. pulex 95% Confidence Interval = N/A; slope = N/A 

D D. magna 95% Confidence Interval = 0.44-0.75 mg a.i./L; slope and its 95% C.I. = 3.18 (2.13-4.23) 

E D. magna 95% Confidence Interval = 14.1-21.3 mg a.i./L; slope and its 95% C.I. = 4.46 (2.9-6.0) 

1

 No chemical analyses were performed on the test concentrations for the presence of the active ingredient or 

formulation especially when mortality/immobility were observed. 

2

 The test solutions were aerated after the test material was added; the dissolved oxygen data was not reported to 

verify the need to aerate the test solutions.
76 

AMMONIUM SALTS OF FATTY ACIDS

A 48h static-renewal acute exposure study (MRID 42806406; Supplemental) with daphnids 

(Daphnia magna) is available for a 13.1% ammonium salts of fatty acids formulation. Twenty 

daphnids per level were exposed to nominal concentrations of 0 (control), 12, 20, 33, 52, 79 and 

131 mg a.i./L (corrected for purity). 90, 100, 100 and 100% mortalities occurred at the 33, 52, 

79 and 131 mg a.i./L concentrations. The immobility EC50 was determined to be 27.1 mg a.i./L; 

the NOAEC was 20 mg a.i./L (adjusted for purity). 100% lethargy was observed in the 33 mg 

a.i./L concentration; in higher concentrations, complete immobility/mortality precluded the 

observations of sublethal effects, the EC50 could not be calculated; the visual-observed NOAEC 

for sub-lethal effects is 20 mg a.i./L. 

A 48h static-renewal acute exposure study (MRID 44760402; Acceptable) with daphnid 

(Daphnia magna) is available for a 22% ammonium salts of fatty acids formulation. Twenty 

daphnids per level were exposed to initial-measured concentrations of 0 (control), 0.5, 0.9, 1.4, 

4.7, 6.6, 22.6, 34.4, 82.3 and 203.7 mg a.i./L (corrected for purity). 5, 10, 55, 100 and 100% 

immobility occurred at the 6.6, 22.6, 34.4, 82.3 and 203.7 mg a.i./L concentrations. The EC50

and NOAEC for immobility was determined to be 30.9 and 22.6 mg a.i./L, respectively (adjusted 

for purity). The sub-lethal effects were not reported since immobility was considered a sub-lethal 

effect by the study authors. 

POTASSIUM SALTS OF FATTY ACIDS

A 48h static acute exposure study (MRID 96638; Supplemental) with daphnids (Daphnia pulex) 

is available for a 50.5% potassium salts of fatty acids formulation. Thirty daphnids per level 

were exposed to nominal concentrations of 0 (control), 50, 100, 150 and 200 mg a.i./L. 33.3, 40, 

73.3 and 100% mortality occurred in the first test and 20, 40, 66.7 and 100% mortality occurred 

in the second test. The study author based its conclusion on dead daphnids; no data on 

immobilized daphnids were available and were not included in the count; it is possible the actual 

EC50 value could be lower if immobilized daphnids had been included in the count. The reviewer 

calculated the LC50 for the first and second tests separately and was 84.7 and 97.6 mg a.i./L, 

respectively; however, the study author reported a LC50 of 106 mg a.i./L by combining the data 

of the tests together. The immobility EC50 is not available since data on immobilization were not 

available. 

A 48h static acute exposure study (MRID 40053305; Acceptable) with daphnids (Daphnia pulex) 

is available for a 25% potassium salts of fatty acids formulation. Twenty daphnids per level 

were exposed to nominal concentrations of 0 (control), 0.25, 0.5, 1.25, 2.5 and 3.75 mg a.i./L. 5, 

55, 85, 95 and 100% effect occurred at the 0.25, 0.5, 1.25, 2.5 and 3.75 mg a.i./L concentrations. 

It appears that the study author based its conclusion on dead daphnids rather than the total of 

daphnids dead and immobilized; it is possible the actual EC50 value could be lower if 

immobilized daphnids had been included in the count. The LC50 based on mortality was 

determined to be 0.57 mg a.i./L. The NOAEC was not determined since >5% effects were 

observed in all levels. The immobility EC50 is not available since data on immobilization were 

not available. 

A 48h static acute exposure study (MRID 44980315; Supplemental) with daphnids (Daphnia 

magna) is available for a 49% potassium salts of fatty acids formulation. Twenty daphnids per 
77 

level were exposed to nominal concentrations of 0 (control), 0.38, 0.76, 1.53, 3.06, 6.13, 12.25, 

24.5, 49 and 98 mg a.i./L (corrected for purity). 35, 65, 100 and 100% immobility occurred at 

the 12.25, 24.5, 49 and 98 mg a.i./L concentrations. The EC50 and NOAEC for immobility was 

determined to be 17.2 and 6.13 mg a.i./L, respectively (adjusted for purity). 

Freshwater Invertebrates, Chronic Effects 

Laboratory toxicity studies using the typical end-use products were submitted to establish the 

chronic toxicity of salts to freshwater invertebrates. Results of the reproduction studies with the 

ammonium and potassium salts formulated products to freshwater invertebrates indicate the 

NOAEC value of 23 mg a.i./L and 0.5 mg a.i./L, respectively, (Table C.3) is used to evaluate 

potential reproductive effects of the salts to freshwater fish. 

Table C.3. Freshwater Invertebrate Chronic Toxicity with Soap Salts (Ammonium and 

Potassium). 

Species % a.i. 21-day 

NOAEC 

(mg a.i./L)

Endpoint 

affected 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Water flea 

(Daphnia 

magna)

21.85 23 

Time to first 

brood release, 

offspring per 

adult, length and 

dry weight 

48402203 

Fournier. (2011) Acceptable 

POTASSIUM SALTS OF FATTY ACIDS

Water flea 

(Daphnia 

magna)

50.1 0.5 

Offspring per 

adult, length and 

parental survival 

48664201 

Sayers. (2011) Acceptable 

Water flea 

(Daphnia 

magna)

46.8 0.52

Time to first 

brood release, 

offspring per 

adult and length 

48668601 

Fournier. (2011) Acceptable 

AMMONIUM SALTS OF FATTY ACIDS

A 21d freshwater invertebrate life-cycle study (MRID 48402203; Acceptable) with daphnids 

(Daphnia magna) is available for a 21.85% ammonium salts of fatty acids formulation. Meanmeasured test concentrations were 0 (control), 4.8, 12, 23, 48 and 100 mg a.i./L. Survival 

averaged 70 to 100% for all levels. The mean day of first brood release averaged 8.3, 8.9, 9.1, 

8.6, 10.2 and 18.1 days for the control and 4.8, 12, 23, 48 and 100 mg a.i./L levels, respectively. 

There was a significant (p <0.05) treatment-related delay in first brood release at the two highest 

treatment levels. The cumulative number of offspring release per female averaged 128 for the 

control, compared to 132, 113, 155, 148 and 14 for the test levels. The difference was 

statistically significant compared to the control (p < 0.05) at the 100 mg a.i./L level. At study 

termination, surviving daphnia from the control and test levels measured 4.6, 4.67, 4.66, 4.71, 

4.72 and 4.02 mm in length and 0.66, 0.76, 0.77, 0.74, 0.8 and 0.55 mg in dry weight with the 

difference statistically-reduced compared to the control at the 100 mg a.i./L level. Offspring per 
78 

adult female, length and weight were affected; however, the time of the first brood releases was 

most affected, the NOAEC is 23 mg a.i./L. 

POTASSIUM SALTS OF FATTY ACIDS

A 21d freshwater invertebrate life-cycle study (MRID 48664201; Acceptable) with daphnids 

(Daphnia magna) is available for a 50.1% potassium salts of fatty acid formulation. Meanmeasured test concentrations were 0 (control), 0.16, 0.31, 0.63, 1.3 and 2.5 mg a.i./L, 46-80% of 

nominal levels. Survival averaged 15 to 100% for all levels, with a statistically-significant 

difference at 1.9 mg a.i./L, the highest test level, when compared to control. The day of first 

brood release was recorded on Day 7 or 8 for the control group and all treatment levels except 

the highest level where no offspring were produced. The day of the first brood release recorded 

was consistent with the control performance. The cumulative number of offspring released per 

female average 149 for the negative control, compared to 182, 182, 178, 65 and 0 for the meanmeasured 0.087, 0.14, 0.5, 0.9 and 1.9 mg a.i./L levels, respectively. The difference was 

statistically-significant compared to the control (p<0.05) at the 0.9 and 1.9 mg a.i./L levels. 

Surviving daphnia from the control group and treatment levels measured 4.8, 4.9, 4.9, 5.0, 4.1 

and 2.7 mm in length and 0.99, 0.98, 1.05, 1.3, 1.04 and 0.59 mg in weight; the difference in 

length was statistically-reduced (p<0.05) compared to the control at the 0.9 and 1.9 mg a.i./L 

levels. No treatment-related reductions were observed for dry weight. Time of first brood release 

and parental survival were affected; however, offspring per adult and length were most affected, 

the NOAEC is 0.5 mg a.i./L. 

A 21d freshwater invertebrate life-cycle study (MRID 48668601; Acceptable) with daphnids 

(Daphnia magna) is available for a 46.8% potassium salts of fatty acid formulation. Meanmeasured test concentrations were 0 (control), 0.091, 0.21, 0.33, 0.52 and 1.4 mg a.i./L, 52-85% 

of nominal levels. Survival averaged 90 – 98% for all levels, with no statistically-significant 

differences from the control. The day of first brood release was recorded on Day 8 for the control 

group and levels up to the 0.52 mg a.i./L treatment level. The day of the first brood release 

recorded for the 1.4 mg a.i./L treatment level was on Day 10. The reviewer interpreted this to be 

a treatment-related delay in first brood release at the highest test level. The cumulative number of 

offspring released per female averaged 115 for the control, compared to 136, 153, 170, 174 and 

85 for the mean-measured 0.091, 0.21, 0.33, 0.52 and 1.4 mg a.i./L levels, respectively. The 

difference was statistically-significant compared to the control (p<0.05) at the highest test level. 

Surviving daphnia from the control and treatment levels measured 4.43, 4.46, 4.53, 4.63, 4.7 and 

4.06 mm in length and 0.93, 1.00, 0.99, 1.02, 1.08 and 0.96 mg in dry weight. The difference in 

length was statistically-reduced (p<0.05) compared to the control at the 1.4 mg a.i./L level. Time 

to first brood releases, offspring per adult and length were equally affected, the NOAEC is 0.52 

mg a.i./L. 

Estuarine/Marine Fish, Acute Effects 

Estuarine/marine fish toxicity studies using the typical end-use products were submitted to 

establish the acute toxicity of salts to fish. Results of the acute studies with the ammonium and 

potassium salts formulated products to estuarine/marine fish indicate the minnow LC50 value of 

>105 mg a.i./L and >4.4 mg a.i./L, respectively, (Table C.4) is used to evaluate potential acute 

effects of the salts to freshwater fish. 
79 

AMMONIUM SALTS OF FATTY ACIDS 

A 96h static-renewal acute exposure study (MRID 48402202; Acceptable) with sheepshead 

minnow (Cyprinodon variegatus) is available for a 21.9% ammonium salts of fatty acids 

formulation. Twenty minnows per level were exposed to Time Weighted Average (TWA) 

concentrations of 0 (control), 6.3, 13, 25, 50 and 100 mg a.i./L. There were no mortality in the 

control and levels up to 50 mg a.i./L; 5% mortality occurred at the 100 mg a.i./L test level, the 

highest level tested. The TWA LC50 is determined to be >105 mg a.i./L. The 5% mortality was 

not statistically-significant, the TWA NOAEC is 105 mg a.i./L. No sub-lethal effects were 

observed in the control or any of the treatment levels. 

POTASSIUM SALTS OF FATTY ACIDS 

A 96h flow-through acute exposure study (MRID 48469802; Acceptable) with sheepshead 

minnow (Cyprinodon variegatus) is available for a 46.8% potassium salts of fatty acids 

formulation. Twenty minnows per level were exposed to mean-measured concentrations of 0 

(control), <LOD, 0.017, 0.35, 1.0 and 2.1 mg a.i./L, 0 to 42% of nominal levels due to rapid 

degradation in seawater. No mortality or sub-lethal effects occurred in the control or in 

treatment levels up to the solubility limit. While the formulated product was used, the 96-hour 

LC50 and NOAEC for the active ingredient is determined to be >2.1 and 2.1 mg a.i./L, 

respectively. 

A 96h flow-through acute exposure study (MRID 48636502; Acceptable) with sheepshead 

minnow (Cyprinodon variegatus) is available for a 50.8% potassium salts of fatty acids 

formulation. Twenty minnows per level were exposed to mean-measured concentrations of 0 

(control), <LOD, 0.12, 0.76, 2.9 and 4.4 mg a.i./L, 9.4 to 85% of nominal levels due to rapid 

degradation in seawater. No mortality or sub-lethal effects occurred in the control or in 

treatment levels up to the solubility limit. The 96-hour LC50 and NOAEC for the active 

ingredient is determined to be >4.4 and 4.4 mg a.i./L, respectively. 

Table C.4. Estuarine/Marine Fish Acute Toxicity with Soap Salts (Ammonium and 

Potassium). 

Species % a.i. 96-hour 

LC50 (mg 

a.i./L)

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Sheepshead minnow 

(Cyprinodon 

variegates)

21.9 >105 Practically 

nontoxic 

48402202 

Fournier. (2011) Acceptable 

POTASSIUM SALTS OF FATTY ACIDS

Sheepshead minnow 

(Cyprinodon 

variegates)

46.8 >2.1 

No effects 

up to 2.1 

mg/L 

48469802 

Fournier. (2011) Acceptable 

50.8 >4.4

No effects 

up to 4.4 

mg/L 

48636502 

Sayers. (2011) Acceptable 
80 

Estuarine/Marine Fish, Chronic Effects 

AMMONIUM and POTASSIUM SALTS OF FATTY ACIDS 

No chronic ecological effects studies of ammonium and potassium salts using estuarine/marine 

fish were submitted. 

Estuarine/Marine Invertebrates, Acute Effects 

Toxicity studies using the typical end-use products were submitted to establish the acute toxicity 

of salts to estuarine/marine invertebrates. Results of the acute studies with the ammonium and 

potassium salts formulated products to estuarine/marine invertebrates indicate the mysid shrimp 

LC50 value of 66.5 mg a.i./L and 1.2 mg a.i./L, respectively, (Table C.5) is used to evaluate 

potential acute effects of the salts to estuarine/marine invertebrates. No data on Eastern oysters 

were available, this is a data gap and the value is discussed further in the risk description section. 

Table C.5. Estuarine/Marine Invertebrate Acute Toxicity with Soap Salts (Ammonium and 

Potassium). 

Species % a.i. 96-hour 

LC50/EC50 

 (mg a.i./L)

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Mysid shrimp 

(Americamysis 

bahia)

21.85 66.5 A Slightly 

toxic 

48402201 

Fournier. (2011) Acceptable 

Eastern oyster 

(Crassostrea 

virginica) 

-- -- -- No data -- 

POTASSIUM SALTS OF FATTY ACIDS

Mysid shrimp 

(Americamysis 

bahia)

46.8 >2.2

No effects 

up to 2.2 

mg a.i./L 

48469801 

Fournier. (2011) Acceptable 

50.8 1.2 B Moderately 

toxic 

48608707 

Sayers. (2011) Acceptable 

Eastern oyster 

(Crassostrea 

virginica) 

-- -- -- No data -- 

A Mysid 95% Confidence Interval = 54.1-85.7 mg a.i./L; slope = N/A (moving average) 

B Mysid 95% Confidence Interval = 0.9 – 1.6 mg a.i./L; slope = N/A (binominal) 

AMMONIMUM SALTS OF FATTY ACIDS 

A 96h static-renewal acute exposure study (MRID 48402201; Acceptable) with mysid shrimp 

(Americamysis bahia) is available for a 21.85% ammonium salts of fatty acids formulation. 
81 

Twenty mysids per level were exposed to time-weighted average concentrations of 0 (control), 

3.3, 8, 20, 45 and 125 mg a.i./L. All mysids in the control group and TWA-measured 8.0 mg 

a.i./L were normal throughout the test. At test termination, 10, 5, and 5% mortality was observed 

in the lowest test level (3.3 mg a.i./L), 20 and 45 mg a.i./L. Complete mortality was observed in 

the highest test level. The LC50 is determined to be 66.5 mg a.i./L; the NOAEC via Fisher’s 

Exact Test is 45 mg a.i./L. Data on the sublethal effects observations were not available for 

analysis. 

No acute ecological effects studies of ammonium salts using mollusks were submitted. 

POTASSIUM SALTS OF FATTY ACIDS 

A 96h flow-through acute exposure study (MRID 48469801; Acceptable) with juvenile mysids 

(Americamysis bahia) is available for a 46.8% potassium salts of fatty acids formulation. 

Twenty mysids per level were exposed to mean-measured concentrations of 0 (control), 0.081, 

<0.034, 0.31, 1.1 and 2.2 mg a.i./L. Two and three mysids died in the control group and the 

lowest test level, respectively, and two died at the third highest test level, considering the 

naturally occurring variability in mortality, the reviewer agrees the mysids that died were not 

treatment-related. Mysids were normal in all other test levels. The LC50 is >2.2 mg a.i./L. The 

NOAEC is 2.2 mg a.i./L, the highest test level tested. The EC50 is not available since data on 

sublethal effects were not available. 

A 96h flow-through acute exposure study (MRID 48608707; Acceptable) with young adult 

mysids (Americamysis bahia) is available for a 50.8% potassium salts of fatty acids formulation. 

Twenty mysids per level were exposed to mean-measured concentrations of 0 (control), <0.059, 

0.17, 0.9, 1.6 and 5.0 mg a.i./L. One mysid died at the lowest level and 100% mortality was 

observed in the two highest test levels at test termination. The reviewer felt that the mysid that 

died in the lowest level is considered naturally occurring variability and not an adverse response. 

The LC50 is 1.2 mg a.i./L; the NOAEC is 0.9 mg a.i./L. The EC50 on sublethal effects is not 

available since data were not available for analysis. 

No acute ecological effects studies of potassium salts using mollusks were submitted. 

Estuarine/Marine Invertebrates, Chronic Effects 

AMMONIUM and POTASSIUM SALTS OF FATTY ACIDS 

No chronic ecological effects studies of ammonium and potassium salts using estuarine/marine 

invertebrates were submitted. 

Effects to Aquatic Vascular and Non-vascular Plants 

Potassium salts studies were submitted for a freshwater vascular plant (duckweed, Lemna gibba) 

and four phytoplanktonic nonvascular plants: a green algae (Pseudokirchneriella subcapitata), a 

cyanobacteria (Anabaena flos-aquae), a freshwater diatom (Navicula pelliculosa) and a marine 

alga (Skeletonema costatum). Duckweed and P. subcapitata were the only plants tested for 

ammonium salts, the effects to the three other phytoplanktonic nonvascular plants listed above 

exposed to ammonium salts are unknown. In each of these studies, because the salts rapidly 
82 

degrade by metabolism, no salts were detected at the end of the studies. However, based on the 

Pesticide Reregistration Rejection Rate Analysis (USEPA 1994), under such a circumstance, 

analysis is based on the initial measured concentrations. 

Aquatic plant toxicity studies using the typical end-use products were submitted to establish the 

toxicity of potassium and ammonium salts to vascular and non-vascular species. Results of the 

studies with the ammonium and potassium salts formulated products to aquatic plants indicate 

nonvascular plants were more sensitive than vascular plants to salts. EC50 values of 200 and 6.6 

for ammonium salts and of >5.0 and 0.59 mg a.i./L for potassium salts (Table C.6) were used to 

evaluate potential effects of the salts to non-listed aquatic vascular and non-vascular plants, 

respectively. Corresponding NOAEC values of 15 and 2.9 mg a.i./L for ammonium salts and of 

0.3 and 0.39 mg a.i./L for potassium salts were used to evaluate potential effects of the salts to 

listed aquatic vascular and nonvascular plants, respectively. 

Table C.6. Aquatic Plant Toxicity with Soap Salts (Ammonium and Potassium). 

Species % a.i. EC50 

(mg a.i./L)

NOAEC 

(mg a.i./L) 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Vascular Plants 

Duckweed

Lemna gibba 21.9 200 A 30 48402206 

Softcheck. (2011) Acceptable 

Non-Vascular Plants

Marine diatom 

Skeletonema costatum -- -- -- No data -- 

Freshwater blue-green 

algae 

Anabaena flos-aquae 

-- -- -- No data -- 

Freshwater diatom 

Navicula pelliculosa -- -- -- No data -- 

Freshwater green algae 

Pseudokirchneriella 

subcapitata 

21.9 6.6B 2.9 48402207 

Softcheck. (2011) Acceptable 

POTASSIUM SALTS OF FATTY ACIDS

Vascular Plants

Duckweed

Lemna gibba

46.8 >19 19 48469803 

Softcheck. (2011) Acceptable 

50.8 >5.0 5.0 48608702 

Softcheck. (2011) Acceptable 

Non-Vascular Plants 

Marine diatom 

Skeletonema costatum 50.8 8.1 C 1.2 48608705 

Softcheck. (2011) Acceptable 

Freshwater blue-green 

algae 

Anabaena flos-aquae 

50.8 5.4 D 2.6 48636501 

Softcheck. (2011) Acceptable 

Freshwater diatom 

Navicula pelliculosa 50.8 0.59 E 0.39 48608701 Acceptable 
83 

Table C.6. Aquatic Plant Toxicity with Soap Salts (Ammonium and Potassium). 

Species % a.i. EC50 

(mg a.i./L)

NOAEC 

(mg a.i./L) 

MRID No. 

Author/Year 

Study 

Classification 

Softcheck. (2011) 

Freshwater green algae 

Pseudokirchneriella 

subcapitata 

50.8 0.86 F 0.63 48608706 

Softcheck. (2011) Acceptable 

46.8 2.9 G 1.2 48402303 

Softcheck. (2011) Acceptable 

A Duckweed 95% Confidence Interval (C.I.) = 170-240 mg a.i./L

B Freshwater green algae 95% C.I. = 5.3-8.2 mg a.i./L C Marine diatom 95% C.I. = 6.4-10 mg a.i./L 

D Blue-green algae 95% C.I. = 4.8-5.9 mg a.i./L 

E Freshwater diatom 95% C.I. = 0.43-0.82 mg a.i./L 

F Green algae 95% C.I. = 0.46-1.6 mg a.i./L G Green algae 95% C.I. = 1.2-3.2 mg a.i./L

AMMONIUM SALTS OF FATTY ACIDS 

In a 7-day static-renewal toxicity study, the aquatic vascular plant duckweed (Lemna gibba) was 

exposed to a 21.9% ammonium salts of fatty acids formulation (MRID 48402206; Acceptable). 

Measured concentrations at Day 0 ranged from 110 to 120% of nominal and by Day 3 dropped 

below the level of quantitation in the three lowest levels; thus, the initial-measured 

concentrations of 0 (control), 4.3, 11, 30, 68, 170, 430 and 1100 mg a.i./L were used in the 

calculations. All endpoints were affected with frond density the most sensitive endpoint, with 

EC50 and NOAEC values of 200 and 30 mg a.i./L, respectively. The % growth inhibition of frond 

density in the treated culture as compared to the control ranged from -6 to 96%. Smaller frond 

size, less root formation, curled and chlorotic fronds were observed in the ≥170 mg a.i./L 

treatment levels. 

In a 96-hour static toxicity study, the green algae Pseudokirchneriella subcapitata was exposed 

to a 21.9% ammonium salts of fatty acids formulation (MRID 48402207; Acceptable). 

Measured concentrations at Day 0 ranged from 100 – 123% of nominal and by test termination 

dropped below the level of quantitation in all test levels; thus, the initial-measured concentrations 

of 0 (control), 1.6, 2.9, 5.3, 10 and 20 mg a.i./L were used in the calculations. Cell density was 

the most sensitive endpoint, with 96-hour EC50 and NOAEC values of 6.6 and 2.9 mg a.i./L, 

respectively. The % growth inhibition of cell density in the treated culture as compared to the 

control ranged from -1 to 87%. No signs of injury occurred and the cells were observed to be 

normal throughout the test. 

No ecological effects studies of ammonium salts using the three remaining phytoplanktonic 

nonvascular plants (freshwater and marine diatom and blue-green algae) were submitted. 

POTASSIUM SALTS OF FATTY ACIDS 

In a 7-day static-renewal toxicity study, the aquatic vascular plant duckweed (Lemna gibba) was 

exposed to a 46.8% potassium salts of fatty acids formulation (MRID 48469803; Acceptable). 
84 

Measured concentrations at Day 0 ranged from 90 to 100% of nominal and by Day 7 dropped 

below the level of quantitation in all test levels; thus, the initial-measured concentrations of 0 

(control), 1.2, 2.5, 4.5, 9.7 and 19 mg a.i./L were used in the calculations. None of the endpoints 

inhibited 50% or more, with EC50 and NOAEC values all >19 and 19 mg a.i./L, respectively. The 

% growth inhibition of frond density in the treated culture as compared to the control ranged 

from -2 to 6%. Fronds were observed to be normal in all test levels. 

In a 7-day static-renewal toxicity study, the aquatic vascular plant duckweed (Lemna gibba) was 

exposed to a 50.8% potassium salts of fatty acids formulation (MRID 48608702; Acceptable). 

Measured concentrations at Day 0 ranged from 98-100% of nominal and by Day 7 dropped 

below the level of quantitation in all test levels; thus, the initial-measured concentrations of 0 

(control), 0.3, 0.63, 1.2, 2.5 and 5.0 mg a.i./L were used in the calculations. None of the frond 

density, biomass or growth rate were inhibited 50% or more in the test, with an EC50 value of 

>5.0 mg a.i./L for all endpoints. A statistically significance difference in frond density and dry 

frond weight was observed in all test levels when compared to the control group, making the 

NOAEC below the lowest test concentration tested (<0.3 mg a.i./L). However, a closer look at 

the statistical results indicated the control group outperformed the data of all treatment groups 

when compared which explains why the NOAEC could not be determined with significant 

differences at all test levels, while results within the treatment groups were not statistically 

significant among treatment levels when compared. If a graph was plotted with inhibition the 

highest in the middle and lowest at the lowest and highest test concentrations, a shallow bellshaped dose-response curve would be observed rather than a monotonically decreasing dose 

response curve. Therefore, it was determined by the reviewer that the statistically significance 

differences were not biologically significant and that none of the endpoints were affected. 

Fronds were observed to be normal in all test levels. 

In a 96-hour static toxicity study, the marine diatom Skeletonema costatum was exposed to a 

50.8% potassium salts of fatty acids formulation (MRID 48608705; Acceptable). Measured 

concentrations at Day 0 ranged from 76-99% of nominal and by test termination dropped below 

the level of quantitation in all test levels; thus, the initial-measured concentrations of 0 (control), 

0.62, 1.2, 1.9, 4.4 and 8.8 mg a.i./L were used in the calculations. Biomass was the most 

sensitive endpoint, with 96-hour EC50 and NOAEC values of 8.1 and 1.2 mg a.i./L, respectively. 

The % growth inhibition of biomass in the treated culture as compared to the control ranged from 

3 to 53%. No signs of injury occurred and the cells were observed to be normal throughout the 

test. 

In a 96-hour static toxicity study, the freshwater blue-green algae Anabaena flos-aquae was 

exposed to a 50.8% potassium salts of fatty acids formulation (MRID 48636501; Acceptable). 

Measured concentrations at Day 0 ranged from 100-104% of nominal and by test termination 

dropped below the level of quantitation in all test levels; thus, the initial-measured concentrations 

of 0 (control), 0.63, 1.3, 2.6, 5.0 and 10 mg a.i./L were used in the calculations. Biomass was the 

most sensitive endpoint, with 96-hour EC50 and NOAEC values of 5.4 and 2.6 mg a.i./L, 

respectively. The % growth inhibition of biomass in the treated culture as compared to the 

control ranged from -4 to 93%. No signs of injury occurred and the cells were observed to be 

normal throughout the test. 

In a 96-hour static toxicity study, the freshwater diatom Navicula pelliculosa was exposed to a 

50.8% potassium salts of fatty acids formulation (MRID 48608701; Acceptable). Measured 
85 

concentrations at Day 0 ranged from 84-100% of nominal and by test termination dropped below 

the level of quantitation in all test levels; thus, the initial-measured concentrations of 0 (control), 

0.084, 0.18, 0.39, 0.79 and 1.6 mg a.i./L were used in the calculations. Cell density was the most 

sensitive endpoint, with 96-hour EC50 and NOAEC values of 0.59 and 0.39 mg a.i./L, 

respectively. The % growth inhibition of cell density in the treated culture as compared to the 

control ranged from -27 to 98%. No signs of injury occurred and the cells were observed to be 

normal throughout the test. 

 In a 96-hour static toxicity study, the freshwater green algae Pseudokirchneriella subcapitata 

was exposed to a 50.8% potassium salts of fatty acids formulation (MRID 48608706; 

Acceptable). Measured concentrations at Day 0 ranged from 93.8-100% of nominal and by test 

termination dropped below the level of quantitation in all test levels except the highest 

concentration; thus, the initial-measured concentrations of 0 (control), 0.1, 0.26, 0.63, 1.5, 3.8 

and 9.5 mg a.i./L were used in the calculations. Cell density was the most sensitive endpoint, 

with 96-hour EC50 and NOAEC values of 0.86 and 0.63 mg a.i./L, respectively. The % growth 

inhibition of cell density in the treated culture as compared to the control ranged from -4 to 98%. 

No signs of injury occurred and the cells were observed to be normal throughout the test. 

In a 96-hour static toxicity study, the freshwater green algae Pseudokirchneriella subcapitata 

was exposed to a 46.8% potassium salts of fatty acids formulation (MRID 48402303; 

Acceptable). Measured concentrations at Day 0 ranged from 92.3-100% of nominal and by test 

termination dropped below the level of quantitation in the lowest test level while the remaining 

test levels were 1.5 – 5.8% of nominal; thus, the initial-measured concentrations of 0 (control), 

0.6, 1.2, 2.4, 4.7 and 10 mg a.i./L were used in the calculations. Biomass was the most sensitive 

endpoint, with 96-hour EC50 and NOAEC values of 2.0 and 0.6 mg a.i./L, respectively. The % 

growth inhibition of biomass in the treated culture as compared to the control ranged from 27 to 

98%. No signs of injury occurred and the cells were observed to be normal throughout the test. 

Birds, Acute Oral 

Acute avian oral toxicity studies using the typical end-use products were submitted to establish 

the acute toxicity of salts to birds via the oral route (Table C.7). No acute oral data on passerine 

birds for potassium salts and on any bird species for ammonium salts were available, bridging 

data from other salts are used as a surrogate. 
86 

Table C.7. Avian Acute Oral Toxicity with Soap Salts (Ammonium and Potassium). 

Species % a.i. Nominal 

LD50 

(mg a.i./kg 

bw) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Passerine bird n/a n/a n/a No data n/a 

Northern bobwhite 

quail or mallard duck n/a n/a n/a No data n/a 

POTASSIUM SALTS OF FATTY ACIDS

Passerine bird n/a n/a n/a No data n/a 

Mallard duck 

(Anas platyrhynchos) 

50 >2500 A Practically 

nontoxic 

00030861 

Hunsaker. 1979. Supplemental1

50.5 >2000 A Practically 

nontoxic 

00096639 

Fink et al. 1981. Acceptable 

Northern bobwhite 

quail 

(Colinus virginianus)

Not 

reported 

>2250 mg 

formulation/

kg bw 

Could not 

be 

determined 

40053301 

Grimes & Jaber. 1987. Supplemental2

25 >2000 A Practically 

nontoxic 

40066202 

Hiken & Jaber. 1987. Acceptable 

60 >1350 

No effects 

up to 1350 

mg a.i./kg 

bw 

0157471 

Beavers. 1986. Supplemental3

49 >2450 A Practically 

nontoxic 

44980310 

Stadens-peek & Leopold 

1996. 

Acceptable 

A The LD50 was greater than the highest concentration; therefore, it was not possible to calculate a probit slope and 95% 

confidence intervals. 

1 Not enough of the birds tested at the 5000 mg/kg bw dose level were the proper age. There was no mention of the pretest condition of the ducks or the climatic conditions of the test chamber if indoors or the atmospheric conditions if 

outdoors. 

2 The purity of the active ingredient in the formulation was not reported; it was not possible to convert to mg active 

ingredient/kg bw.

3 The concentrations used (when adjusted for active ingredient) did not produce a precise LD50 and the highest 

concentration was below 2000 mg a.i./kg bw. 

AMMONIUM SALTS OF FATTY ACIDS 

No ecological effects studies of ammonium salts using an upland game bird or waterfowl and a 

passerine bird were submitted. 

POTASSIUM SALTS OF FATTY ACIDS 

The acute oral toxicity of a 50.5% potassium salts of fatty acids formulation (MRID 00030861; 

Supplemental) to juvenile and young mallard ducks (Anas platyrhynchos) was assessed over 48 
87 

hours and held for an additional 5 days for post-observation. The formulation was administered 

in corn oil to a total of 31 ducks comprising two groups of differing ages per treatment level by 

gavage at nominal concentrations of 0 (control) and 500 mg a.i./kg bw. No mortality was 

observed in the controls or at the limit dose. Following the completion of the study, an additional 

dose at 2500 mg a.i./kg bw using ducks from the previous study were subsequently added to 

observe for any mortality at the higher dose. As a result, none of the juvenile or young ducks 

died at 500 or 2500 mg a.i./kg bw. Raw data were not available to verify the author’s conclusions 

on sublethal effects; however, the author reported there were no externally observable effects on 

the behavior or physiology of ducks, including no decline in vigor or in food and water intake. 

The young ducks were able to reproduce, lay eggs, and engage in normal adult preening 

behavior. The 48-hours acute oral LD50 is >2500 mg a.i/kg bw based on a lack of mortality and 

sub-lethal effects. 

The acute oral toxicity of a 50.5% potassium salts of fatty acids formulation (MRID 00096639; 

Supplemental) to 6-month old mallard ducks (Anas platyrhynchos) was assessed over 14 days. 

The formulation was administered to ducks per treatment level by gavage at nominal 

concentrations of 0 (control), 201, 319, 505, 803 and 1268 mg a.i./kg bw (corrected for purity) 

and a second trail conducted at 2000 mg a.i./kg bw. No mortality was observed in the controls or 

in the treatment groups. Overall percent body weight change during the 14-day exposure period 

averaged 1.9% in the control and 2.4, 1.0, 1.8, 4.5 and 6% in the nominal 201, 319, 505, 803 and 

1268 mg a.i./kg bw treatment groups, respectively. In the 2nd study with the nominal 2,000 mg 

a.i./kg bw treatment group, overall % body weight change averaged 0% as compared to 3% in 

the vehicle control. The mean food consumption in the control and nominal 201, 319, 505, 803 

and 1268 mg a.i./kg bw treatment groups during 1-7 day period was 91 g in the control and 101, 

81, 94, 112 and 100 g in the treatment groups, respectively, yielding inhibitions of -10, 11, -3, -

23 and -10%, respectively. During the 8-14 day period, mean food consumption in the control 

was 96 g and 88, 104, 105, 106 and 103 g in the treatment groups, yielding inhibitions of 8, -8, -

9, -10 and -7%. In the 2nd study with the nominal 2,000 mg a.i./kg bw treatment group, mean 

food consumption was inhibited 24% during the 1-7 day period and -12% during the 8-14 day 

period when compared to control. The 14-day acute oral LD50 is >2000 mg a.i./kg bw based on a 

lack of mortality and sub-lethal effects. 

The acute oral toxicity of a potassium salts of fatty acids formulation (MRID 40053301; 

Supplemental) to 26-week old bobwhite quails (Colinus virginianus) was assessed over 14 days. 

The formulation was administered to birds per treatment level by gavage at nominal 

concentrations of 0 (control) 292, 486, 810, 1350 and 2250 mg formulation/kg bw (% a.i. not 

reported, values not corrected for purity). No mortality was observed in the controls or in the 

treatment groups. Overall percent body weight change for both males and females during the 14-

day test period average 7% in the control and 6, 5, 5, 6 and 6% in the nominal 292, 486, 810, 

1350 and 2250 mg formulation/kg bw treatment groups, respectively. The mean food 

consumption in the control and nominal 292, 486, 810, 1350 and 2250 mg formulation/kg bw 

treatment groups during the1-7 day period was 45 g in the control and 67, 55, 50, 43 and 35 g in 

the treatment groups, respectively, yielding inhibitions of -33, -22, -11, 4 and 22%, respectively. 

During the 8-14 day test period, mean food consumption in the control and nominal 292, 486, 

810, 1350 and 2250 mg formulation/kg bw treatment groups was 45 g in the control and 51, 46, 

47, 37 and 33 g in the treatment groups, respectively, yielding inhibitions of -13, -2, -4, 18 and 

27%. The 14-day acute oral LD50 is >2250 mg formulation/kg bw (not corrected for purity) 

based on a lack of mortality and sub-lethal effects. 
88 

The acute oral toxicity of a 25% potassium salts of fatty acids formulation (MRID 40066202; 

Acceptable) to 31-week old bobwhite quails (Colinus virginianus) was assessed over 14 days. 

The formulation was administered to birds per treatment level by gavage at nominal 

concentrations of 0 (control), 500, 1000 and 2000 mg a.i./kg bw. No mortality was observed in 

the controls or in the treatment groups. Overall percent body weight change for both males and 

females during the 14-day test period average 10% in the control and 8, 9 and 8% in the nominal 

500, 1000 and 2000 mg a.i./kg bw treatment groups, respectively. The mean food consumption 

in the control and nominal 500, 1000 and 2000 mg a.i./kg bw treatment groups during the1-7 day 

period was 42 g in the control and 43, 37 and 45 g in the treatment groups, respectively, yielding 

inhibitions of -2, 12 and -7%, respectively. During the 8-14 day test period, mean food 

consumption in the control and nominal 500, 1000 and 2000 mg a.i./kg bw treatment groups was 

33 g in the control and 38, 30 and 46 g in the treatment groups, respectively, yielding inhibitions 

of -15, 9 and -40%. The 14-day acute oral LD50 is >2000 mg a.i./kg bw based on a lack of 

mortality and sub-lethal effects. 

The acute oral toxicity of a 60% potassium salts of fatty acids formulation (MRID 00157471; 

Supplemental) to 22-week old bobwhite quails (Colinus virginianus) was assessed over 14 days. 

The formulation was administered to birds per treatment level by gavage at nominal 

concentrations of 0 (control), 175, 292, 486, 810 and 1350 mg a.i./kg bw (corrected for purity). 

No mortality was observed in the controls or in the treatment groups. Overall percent body 

weight change for both males and females during the 14-day test period average 7% in the 

control and 7, 8, 7, 9 and 5% in the nominal 175, 292, 486, 810 and 1350 mg a.i./kg bw 

treatment groups, respectively. The mean food consumption in the control and nominal 175, 292, 

486, 810 and 1350 mg a.i./kg bw treatment groups during the1-7 day period was 58 g in the 

control and 59, 60, 52, 57 and 56 g in the treatment groups, respectively, yielding inhibitions of -

2, -3, 10, 2 and 3%, respectively. During the 8-14 day test period, mean food consumption in the 

control and nominal 175, 292, 486, 810 and 1350 mg a.i./kg bw treatment groups was 48 g in the 

control and 47, 49, 43, 51 and 49 g in the treatment groups, respectively, yielding inhibitions of 

2, 8, 10, -6 and -2%. The 14-day acute oral LD50 is >1350 mg a.i./kg bw based on a lack of 

mortality and sub-lethal effects. 

The acute oral toxicity of a 49% potassium salts of fatty acids formulation (MRID 44980310; 

Acceptable) to 21-week old bobwhite quail (Colinus virginianus) was assessed over 15 days. The 

formulation was administered to birds per the limit dose by gavage at a nominal concentration of 

2450 mg a.i./kg bw (corrected for purity). No mortality was observed in the controls or in the 

limit dose. Overall percent body weight change for both males and females during the 15-day 

test period average 3% in the control and 4% in the nominal 2450 mg a.i./kg bw treatment group. 

The mean food consumption in the control and nominal 2450 mg a.i./kg bw treatment group 

during the1-8 day period was 15 g in the control and 15 g in the treatment group, yielding an 

inhibition of 0%. During the 8-15 day test period, mean food consumption in the control and 

nominal 2450 mg a.i./kg bw treatment group was 14 g in the control and 15 g in the treatment 

group, yielding an increase of 7%. The 15-day acute oral LD50 is >2450 mg a.i./kg bw based on a 

lack of mortality and sub-lethal effects. 

No ecological effects studies of potassium salts using a passerine bird were submitted. 
89 

Birds, Subacute Dietary 

Subacute avian dietary toxicity studies using the typical end-use products were submitted to 

establish the acute toxicity of salts to birds via the dietary route (Table C.8). No acute dietary 

data on a waterfowl for ammonium salts were available, bridging data from other salts are used 

as a surrogate. 
90 

Table C.8. Avian Acute Dietary Toxicity with Soap Salts (Ammonium and Potassium). 

Species % a.i. Nominal LC50 

(mg a.i./kg diet) 

Toxicity 

Category 

MRID No. 

Author/Year 

Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS

Mallard duck 

(Anas platyrhynchos) n/a n/a n/a No data n/a 

Japanese quail 

(Coturnix japonica) 22 >1,100 

No effects up to 

1,100 mg 

a.i./kg diet 

46206301 

Bien. 2003. Acceptable 

POTASSIUM SALTS OF FATTY ACIDS

Mallard duck 

(Anas platyrhynchos)

Not 

report

ed 

>10,000 mg 

formulation/kg 

diet 

Could not be 

determined 

00105040 

Beavers & Fink. 1981. Supplemental1

60 >3,372 

No effects up to 

3,372 mg 

a.i./kg diet 

40385601 

Johnson & Jaber. 1987. Acceptable 

49 >2,450 

No effects up to 

2,450 mg 

a.i./kg diet 

44980312 

Leopold. 1997. Acceptable 

25 >1,405 

No effects up to 

1,405 mg 

a.i./kg diet 

40053303 

Grimes & Jaber. 1986. Supplemental 

25 >5620 Practically 

nontoxic 

40066204 

Grimes & Jaber. 1987. Acceptable 

50 >2,642 

No effects up to 

2,642 mg 

a.i./kg diet 

00030862 

Condrashoff. 1979. Supplemental 

Northern bobwhite quail 

(Colinus virginianus)

60 >3372 

No effects up to 

3372 mg a.i./kg 

diet 

00157472 

Beavers. 1986. Acceptable 

25 >1,405 

No effects up to 

1,405 mg 

a.i./kg diet 

40053302 

Grimes & Jaber. 1986. Supplemental 

Not 

report

ed 

>10,000 mg 

formulation/kg 

diet 

Could not be 

determined 

00096640 

Beavers & Fink. 1981. Supplemental1

25 >5620 Practically 

nontoxic 

40066203 

Grimes et al. 1987. Acceptable 

50 >2,642 

No effects up to 

2,642 mg 

a.i./kg diet 

00030863 

Condrashoff. 1979. Supplemental 

49 >2450 A

No effects up to 

2,450 mg 

a.i./kg diet 

44980311 

Leopold. 1997. Acceptable 

A The LD50 was greater than the highest concentration; therefore, it was not possible to calculate a probit slope and 95% 

confidence intervals. 

1 The % of the active ingredient in the formulation was not reported; thus, it was not possible to correct the toxicity value 

to the active ingredient.
91 

AMMONIUM SALTS OF FATTY ACIDS 

In an 8-day acute dietary toxicity study, the 8-day old Japanese quail (Coturnix japonica) was 

exposed to a 22% ammonium salts of fatty acids formulation (MRID 46206301; Acceptable). 

The formulation was administered to the birds in the diet at nominal concentrations of 0 (control) 

and 1,100 mg a.i./L (corrected for purity). No mortalities were observed. Percent body weight 

change during the 5-day exposure period averaged 40.7% in the control and 38.3% in the 1,100 

mg a.i./kg diet treatment group yielding an inhibition of 5.8%. Percent body weight gain during 

the 3-day observation period (days 6-8) averaged 15.9% in the control and 18.6% in the 

treatment group yielding an increase of 17%. The overall % body weight gain was 50.2% in the 

control and 49.8% in the treatment group. The mean food consumption in the control and 

treatment group during the exposure period (days 0-5) was 134 and 123 g, respectively, yielding 

an inhibition of 8.2% and mean food consumption in the control and treatment group during the 

observation period was 178 and 169 g, respectively, yielding an inhibition of 5.1%. The 8-day 

LC50 is >1,100 mg a.i./kg diet (corrected for purity) based on a lack of mortality and sub-lethal 

effects. 

POTASSIUM SALTS OF FATTY ACIDS 

In an 8-day acute dietary toxicity study, the 14-day old mallard duck (Anas platyrhynchos) was 

exposed to a potassium salts of fatty acids formulation (MRID 00105040; Supplemental). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 562, 1000, 1780, 3160 and 5620 mg formulation/kg diet and a second trail conducted at 

10,000 mg formulation/kg diet (% a.i. not reported, values not corrected for purity). No 

mortalities or behavioral abnormalities were observed. Percent body weight change during the 5-

day exposure period averaged 46% in the control and 47.1, 46.7, 48.1, 49.4 and 43.2% in the 

nominal 562, 1000, 1780, 3160 and 5620 mg/kg diet treatment groups, respectively, yielding 

inhibitions of -2.3, -1.5, -4.5, -7.3 and 6%. In the 2nd study with the nominal 10,000 mg/kg 

treatment group, % body weight gain averaged 47.4% as compared to the 44.8% gain in the 

vehicle control, yielding an inhibition of -5.8%. The mean food consumption in the control and 

nominal 562, 1000, 1780, 3160 and 5620 mg/kg diet treatment groups during the exposure 

period (days 0-5) was 3965 g in the control and 4370, 3740, 4279, 3696 and 3882 g in the 

treatment groups, respectively, yielding inhibitions of -10.2, 5.7, -7.9, 6.8 and 2.1%, respectively. 

In the 2nd study with the nominal 10,000 mg/kg diet treatment group, mean food consumption 

was 3814 g as compared to 3827 g in the vehicle control, yielding an inhibition of 0.3% The 8-

day LC50 is >10,000 mg formulation/kg diet (not corrected for purity) based on a lack of 

mortality and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 10-day old mallard duck (Anas platyrhynchos) was 

exposed to a 60% potassium salts of fatty acids formulation (MRID 40385601; Acceptable). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 337.2, 600, 1068, 1896 and 3372 mg a.i./kg diet (corrected for purity). No mortality or 

behavioral abnormalities were observed. Percent body weight change during the exposure period 

averaged 43.2% in the control and 42.1, 42.9, 40.9, 43.3 and 40.5% in the nominal 337.2, 600, 

1068, 1896 and 3372 mg a.i./kg diet treatment groups, respectively, yielding inhibitions of 2.5, 

0.7, 5.3, -0.2 and 6.3%. Percent body weight gain during the observation period averaged 22.7% 

in the control and 22.7, 20.3, 20.0, 22.1 and 22.6% in the 337.2, 600, 1068, 1896 and 3372 mg 

a.i./kg diet treatment groups, respectively, yielding increases of 0, -10.6, -11.9, -2.6 and -0.4%. 
92 

The overall % body weight gain was 55.1% in the control and 55.2, 54.5, 52.8, 55.8 and 54.0% 

in the 337.2, 600, 1068, 1896 and 3372 mg a.i./kg diet groups, respectively. The mean food 

consumption in the control and nominal 337.2, 600, 1068, 1896 and 3372 mg a.i./kg diet 

treatment groups during the exposure period was 64 g in the control and 61, 56, 62, 60 and 53 g, 

respectively, yielding inhibitions of 5, 12, 3, 6 and 17%. Mean food consumption in the control 

and treatment groups during the observation period was 66.2 g in the control and 67, 61, 61, 71 

and 65 g, respectively, yielding inhibitions of -2, 8, 8, -8 and 2%. The 8-day LC50 is >3,372 mg 

a.i./kg diet (corrected for purity) based on a lack of mortality and sub-lethal effects. 

 

In an 8-day acute dietary toxicity study, the 10-day old mallard duck (Anas platyrhynchos) was 

exposed to a 49% potassium salts of fatty acids formulation (MRID 44980312; Acceptable). The 

formulation was administered in the diet to 20 ducks at 2450 mg a.i./kg diet (corrected for 

purity), 10 ducks were exposed to a diet without a vehicle and 10 ducks to a diet mixed with 

acetone. Twenty ducks were exposed to a control diet without a vehicle and twenty ducks to a 

diet mixed with acetone in case inhomogeneity occurred in the diets prepared without a vehicle. 

No mortality or behavioral abnormalities were observed. Percent body weight change during the 

exposure period averaged 42.6% in the control and 41.7% in the nominal 2450 mg a.i./kg diet 

treatment group, yielding an inhibition of 2.1%. For the groups mixed with acetone, the % body 

weight gain averaged 46.2% in the control and 46.3% in the limit dose level, resulting in an 

inhibition of -0.2%. The overall % body weight gain was 52.1% in the control and 51.7% in the 

treatment group without acetone; for the groups mixed with acetone, the gain was 53.9% in the 

control and 58.5% in the treatment group. The mean food consumption in the control and 

nominal 2450 mg a.i./kg diet treatment group during the exposure period was 35 g in the control 

and 38 g, yielding an inhibition of -8.6% and mean food consumption in the control and 

treatment groups during the observation period was 42 g in the control and 43 g, yielding an 

inhibition of -2.4%. The mean food consumption for the groups mixed with acetone during the 

exposure period was 40 g in the control and 37 g in the limit dose, yielding an inhibition of 7.5% 

and mean food consumption during the observation period was 43 g in the control and 47 g in the 

limit dose, yielding an inhibition of -9.3%. The 8-day LC50 is >2450 mg a.i./kg diet (corrected 

for purity) based on a lack of mortality and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 10-day old mallard duck (Anas platyrhynchos) was 

exposed to a 25% potassium salts of fatty acids formulation (MRID 40053303; Supplemental). 

The formulation was administered to the ducks in the diet at nominal concentrations of 0 (vehicle 

control), 140.5, 250, 445, 790 and 1405 mg a.i./kg diet (corrected for purity). Percent body 

weight change during the exposure period averaged 52% in the control and 53.6, 52.7, 51.5, 51.9 

and 51.5% in the nominal 140.5, 250, 445, 790 and 1405 mg a.i./kg diet treatment groups, 

yielding inhibitions of -3.0, -1.3, 1.0, 0.2, 1.0%. The overall % body weight gain was 63.4% in 

the control and 65, 63.2, 63.5, 63.8 and 62.7% in the treatment groups, respectively. The mean 

food consumption in the control and nominal 140.5, 250, 445, 790 and 1405 mg a.i./kg diet 

treatment groups, respectively, during the exposure period was 58.6 g in the control and 61, 56, 

58, 61 and 54 g, respectively, yielding inhibitions of -4.0, 4.4, 1.0, -4.0 and 7.8% and mean food 

consumption in the control and treatment groups during the observation period was 70 g in the 

control and 72, 65, 65, 75 and 73 g, respectively, yielding inhibitions of -2.9, 7.1, 7.1, -7.1 and -

4.3%. The 8-day LC50 is >1405 mg a.i./kg diet (corrected for purity) based on a lack of mortality 

and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 10-day old mallard duck (Anas platyrhynchos) was 
93 

exposed to a 25% potassium salts of fatty acids formulation (MRID 40066204; Acceptable). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 562, 1000, 1780, 3160 and 5620 mg a.i./kg diet. No mortality or behavioral 

abnormalities were observed. Percent body weight change during the exposure period averaged 

45% in the control and 45, 45, 47, 47 and 44% in the nominal 562, 1000, 1780, 3160 and 5620 

mg a.i./kg diet treatment groups, respectively, yielding inhibitions of -4, -2, 5, -4 and 4%. 

Percent body weight gain during the observation period averaged 23% in the control and 23, 26, 

22, 22 and 24% in the 562, 1000, 1780, 3160 and 5620 mg a.i./kg diet treatment groups, 

respectively, yielding increases of 4, 5, -3, 3 and -4%. The overall % body weight gain was 60% 

in the control and 57, 59, 60, 59 and 57% in the 562, 1000, 1780, 3160 and 5620 mg a.i./kg diet 

groups, respectively. The mean food consumption in the control and nominal 562, 1000, 1780, 

3160 and 5620 mg a.i./kg diet treatment groups during the exposure period was 69 g in the 

control and 63, 64, 62, 68 and 62 g, respectively, yielding inhibitions of 9, 7, 10, 1 and 10%. 

Mean food consumption in the control and treatment groups during the observation period was 

83 g in the control and 82, 87, 82, 79 and 78 g, respectively, yielding inhibitions of 1, -5, 1, 5 and 

6%. The 8-day LC50 is >5620 mg a.i./kg diet based on a lack of mortality and sub-lethal effects. 

In a 5-day acute dietary toxicity study, the 14-day old mallard duck (Anas platyrhynchos) was 

exposed to a 50% potassium salts of fatty acids formulation (MRID 00030862; Supplemental). 

The formulation was administered to the ducks in the diet at nominal concentrations of 0 (vehicle 

control) and 2,642 mg a.i./kg diet (corrected for purity). Percent body weight change during the 

exposure period averaged 42.7% in the control and 48.2% in the nominal 2642 mg a.i./kg diet 

treatment groups, yielding an inhibition of -13%. The overall % body weight gain could not be 

assessed since an observation period was not included in the test. The mean food consumption in 

the control and nominal 2642 mg a.i./kg diet treatment group during the exposure period was 

724.9 g in the control and 781.6 g, yielding an inhibition of -7.8%. The mean food consumption 

in the control and treatment group during the observation period could not be assessed since an 

observation period was not included in the test. The 8-day LC50 is >2642 mg a.i./kg diet 

(corrected for purity) based on a lack of mortality and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 10-day old bobwhite quail (Colinus virginianus) was 

exposed to a 60% potassium salts of fatty acids formulation (MRID 00157472; Acceptable). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 337, 600, 1068, 1896 and 3372 mg a.i./kg diet (corrected for purity). No mortality or 

behavioral abnormalities were observed. Percent body weight change during the exposure period 

averaged 40.4% in the control and 46.9, 45.2, 45.5, 44.8 and 45.2% in the nominal 337, 600, 

1068, 1896 and 3372 mg a.i./kg diet treatment groups, respectively, yielding inhibitions of 2.4, 

5.5, -0.6, 11.6 and 5.5%. Percent body weight gain during the observation period averaged 

19.6% in the control and 20, 20.5, 23.3, 21.6 and 20.5% in the 337, 600, 1068, 1896 and 3372 

mg a.i./kg diet treatment groups, respectively, yielding increases of 2.4, 4.9, -4.9, 9.8 and 4.9%. 

The overall % body weight gain was 52.1% in the control and 57.5, 56.4, 58.1, 56.8 and 56.4% 

in the 337, 600, 1068, 1896 and 3372 mg a.i./kg diet groups, respectively. The mean food 

consumption in the control and nominal 337, 600, 1068, 1896 and 3372 mg a.i./kg diet treatment 

groups during the exposure period was 9 g in the control and 13, 10, 11, 11 and 13 g, 

respectively, yielding inhibitions of -44, -11, -22, -22 and -44%. Mean food consumption in the 

control and treatment groups during the observation period was 16 g in the control and 14, 10, 

11, 10 and 13 g, respectively, yielding inhibitions of 12.5, 37.5, 31.3, 37.5 and 18.8%. The 8-day 

LC50 is >3,372 mg a.i./kg diet (corrected for purity) based on a lack of mortality and sub-lethal 
94 

effects. 

In an 8-day acute dietary toxicity study, the 10-day old bobwhite quail (Colinus virginianus) was 

exposed to a 25% potassium salts of fatty acids formulation (MRID 40053302; Supplemental). 

The formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 140.5, 250, 445, 790 and 1405 mg a.i./kg diet (corrected for purity). Percent body 

weight change during the exposure period averaged 40.7% in the control and 37.9, 37, 37, 37.9 

and 39.3% in the nominal 140.5, 250, 445, 790 and 1405 mg a.i./kg diet treatment groups, 

yielding inhibitions of -7.4, 0, 0, -7.4 and -3.7%. Percent body weight gain during the 

observation period averaged 22.9% in the control and 21.6, 25, 20.6, 19.4 and 24.3% in the 

140.5, 250, 445, 790 and 1405 mg a.i./kg diet treatment groups, respectively, yielding increases 

of 5.4, 2.7, -2.9, 2.7 and 5.4%. The overall % body weight gain was 54.3% in the control and 

51.4, 52.8, 50, 50 and 54.1% in the treatment groups, respectively. The mean food consumption 

in the control and nominal 140.5, 250, 445, 790 and 1405 mg a.i./kg diet treatment groups, 

respectively, during the exposure period was 12 g in the control and 10, 11, 8, 13 and 9 g, 

respectively, yielding increases of -20, -9, -50, 7.7 and -33% and mean food consumption in the 

control and treatment groups during the observation period was 12 g in the control and 12, 18, 

11, 20 and 12 g, respectively, yielding increases of 0, 33, -9, 40 and 0%. The 8-day LC50 is 

>1,405 mg a.i./kg diet (corrected for purity) based on a lack of mortality and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 14-day old bobwhite quail (Colinus virginianus) was 

exposed to a potassium salts of fatty acids formulation (MRID 00096640; Supplemental). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 562, 1000, 1780, 3160 and 5620 mg formulation/kg diet and a second trail conducted at 

10,000 mg formulation/kg diet (% a.i. not reported, values not corrected for purity). No 

mortalities or behavioral abnormalities were observed. Overall percent body weight change 

during the test averaged 43.2% in the control and 40.6, 39.4, 42.9, 38.7 and 36.1% in the nominal 

562, 1000, 1780, 3160 and 5620 mg/kg diet treatment groups, respectively, yielding inhibitions 

of 13.5, 10.8, 5.4, 16.2 and 2.7%. In the 2nd study with the nominal 10,000 mg/kg treatment 

group, overall % body weight gain averaged 44.9% as compared to the 47% gain in the vehicle 

control, yielding an increase of 2%. The mean food consumption in the control and nominal 562, 

1000, 1780, 3160 and 5620 mg/kg diet treatment groups during the exposure period (days 0-5) 

was 396 g in the control and 357, 409, 361, 345 and 356 g in the treatment groups, respectively, 

yielding inhibitions of 10.1, -3.0, 9.1, 13.1 and 10.3%, respectively. In the 2nd study with the 

nominal 10,000 mg/kg diet treatment group, mean food consumption was 406 g as compared to 

376 g in the vehicle control, yielding an inhibition of -7.9% The 8-day LC50 is >10,000 mg 

formulation/kg diet (not corrected for purity) based on a lack of mortality and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 10-day old bobwhite quail (Colinus virginianus) was 

exposed to a 25% potassium salts of fatty acids formulation (MRID 40066203; Acceptable). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control), 140.5, 250, 445, 790 and 1405 mg a.i./kg diet (corrected for purity). Percent body 

weight change during the exposure period averaged 36.1% in the control and 33.3, 36.4, 36.7, 

36.4, 34.4% in the nominal 140.5, 250, 445, 790 and 1405 mg a.i./kg diet treatment groups, 

yielding inhibitions of 3.2, -6.5, 3.2, -6.5, and -3.2%. Percent body weight gain during the 

observation period averaged 21.3% in the control and 25, 21.4, 23.1, 21.4 and 22% in the 140.5, 

250, 445, 790 and 1405 mg a.i./kg diet treatment groups, respectively, yielding increases of 1.5, 

6.2, -1.0, 6.2 and 3.9%. The overall % body weight gain was 49.7% in the control and 50, 50, 
95 

51.3, 50 and 48.8% in the treatment groups, respectively. The mean food consumption in the 

control and nominal 140.5, 250, 445, 790 and 1405 mg a.i./kg diet treatment groups during the 

exposure period was 9.4 g in the control and 9, 10, 10, 10 and 11 g, respectively, yielding 

inhibitions of 4.3, -6.4, -6.4, -6.4 and -17% and mean food consumption in the control and 

treatment groups during the observation period was 15 g in the control and 12, 12, 16, 15 and 14 

g, respectively, yielding inhibitions of 20, 20, -6.7, 0.0 and 6.7%. The 8-day LC50 is >1405 mg 

a.i./kg diet (corrected for purity) based on a lack of mortality and sub-lethal effects. 

In a 5-day acute dietary toxicity study, the 14-day old bobwhite quail (Colinus virginianus) was 

exposed to a 50% potassium salts of fatty acids formulation (MRID 00030863; Supplemental). 

The formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control) and 2,642 mg a.i./kg diet (corrected for purity). Percent body weight change during the 

exposure period averaged 37% in the control and 23% in the nominal 2642 mg a.i./kg diet 

treatment groups, yielding an inhibition of 25%. The overall % body weight gain could not be 

assessed since an observation period was not included in the test. The mean food consumption in 

the control and nominal 2642 mg a.i./kg diet treatment group during the exposure period was 

317.2 g in the control and 263.3 g, yielding an inhibition of 17%. The mean food consumption in 

the control and treatment group during the observation period could not be assessed since an 

observation period was not included in the test. The 8-day LC50 is >2642 mg a.i./kg diet 

(corrected for purity) based on a lack of mortality and sub-lethal effects. 

In an 8-day acute dietary toxicity study, the 14-day old bobwhite quail (Colinus virginianus) was 

exposed to a 50% potassium salts of fatty acids formulation (MRID 44980311; Acceptable). The 

formulation was administered to the birds in the diet at nominal concentrations of 0 (vehicle 

control) and 2,450 mg a.i./kg diet (corrected for purity). Percent body weight change during the 

exposure period averaged 33.8% in the control and 33% in the nominal 2450 mg a.i./kg diet 

treatment group, yielding an inhibition of 2.6%. Percent body weight gain during the observation 

period averaged 16.5% in the control and 20.8% in the limit dose, yielding an increase of 1.4%. 

The overall % body weight gain was 44.7% in the control and 46.9% in the limit dose. The mean 

food consumption in the control and nominal 2450 mg a.i./kg diet treatment group during the 

exposure period was 8 g in the control and 8 g in the treatment group, yielding an inhibition of 

0%. The mean food consumption in the control and treatment group during the observation 

period was 9 g in the control and 9 g in the treatment group, yielding an inhibition of 0%. The 8-

day LC50 is >2450 mg a.i./kg diet (corrected for purity) based on a lack of mortality and sublethal effects. 

Birds, Reproduction 

AMMONIUM and POTASSIUM SALTS OF FATTY ACIDS 

No chronic ecological effects studies of ammonium and potassium salts using birds were 

submitted. The Agency is not asking for the ecological studies due to the lack of effects at high 

rates in acute avian studies and the salts undergo rapid degradation via metabolism in less than a 

day. 

Mammals, Acute Oral and Reproduction 
96 

In most cases, rat or mouse toxicity values are obtained from the Agency's Health Effects 

Division (HED) for EFED’s ecological risk assessment to evaluate the potential risk to 

mammalians. In an August 29, 2012 memorandum (D399690), HED has reported the toxicology 

database for soap salts is adequate to support reregistration eligibility. HED has waived all 

generic mammalian toxicity data requirements for soap salts due to the lack of effects at high 

doses in the available studies of other fatty acid salts, the nature of the chemicals (fatty acids) 

and their ubiquity in nature, and the limited potential for human exposure via the oral route from 

established uses. With no systemic toxicity observed, HED did not select endpoints for human 

health risk assessment and waived all mammalian toxicity data; thus, the ecological effects to 

mammals are anticipated to be minimal. 

Beneficial Insects, Acute 

Honeybee acute contact studies were submitted for soap salts because of its wide-ranging uses 

that will result in honeybee exposure (Table III.21). The acute contact LD50, using the honey 

bee, Apis mellifera, is derived from a laboratory study designed to estimate the quantity of 

toxicant required to cause 50% mortality in a test population of bees. Results of the acute contact 

studies with honeybees indicate the formulated products of soap salts are practically non-toxic to 

bees on a contact exposure basis. The available honeybee acute contact and oral studies are 

summarized in C.9. 

Table C.9. Acute Contact and Oral Toxicity of Ammonium and Potassium Salts to Honeybees

Species % a.i. Nominal 

LD50/LC50* 

(μg a.i./bee) 

Toxicity 

Category 

MRID No. Study 

Classification 

AMMONIUM SALTS OF FATTY ACIDS 

Honey bee 

(Apis 

mellifera) 

13.1 >262 (contact) Practically 

nontoxic 

42806407 

Ward et al. 

1993. 

Acceptable 

22 

>100 (contact) Practically 

nontoxic 44766401 

Nengel. 1998. 

Acceptable 

>108.94 (oral) Not categorized Supplemental†

POTASSIUM SALTS OF FATTY ACIDS

Honey bee 

52.8 >13 (contact) Practically 

nontoxic 

42806001 

Hoxter and 

Bernard. 1993. 

Acceptable 

19.9 >5 (contact) 

No significant 

effects up to 5 

μg a.i./bee 

43042801 

Palmer and 

Beavers. 1993. 

Acceptable 

40 >10 (contact) 

No significant 

effects up to 10 

μg a.i./bee 

43173604 

Palmer and 

Beavers. 1993. 

Acceptable 
97 

Table C.9. Acute Contact and Oral Toxicity of Ammonium and Potassium Salts to Honeybees

50.5 

>100 (contact) Practically 

nontoxic 45060901 

Schur. 1999. 

Acceptable 

>96.04 (oral) Not categorized Supplemental†

† Acute oral - a non-guideline study 

* The LD50s/LC50s were greater than the highest concentration; therefore, it was not possible to calculate a 

probit slope and 95% confidence intervals.

AMMONIUM SALTS OF FATTY ACIDS 

The acute contact toxicity of a 13.1% ammonium salt formulated product (MRID 42806407; 

Acceptable) to honey bees (Apis mellifera) was tested in the laboratory. In the 48-hour acute 

contact test, bees were exposed to the formulation administered topically to the thorax, at an 

application rate of 0 (control), 16.4, 32.8, 65.5, 131 and 262 μg a.i./bee. Lethargy was the only 

reported sub-lethal effect and was only observed in the two highest doses. At 48 hours, 10.4% of 

surviving bees in the 131 μg a.i./bee treatment group were lethargic. At 4 hours, one bee of the 

surviving 49 bees in the 262 μg a.i./bee treatment group was lethargic, and at 48 hours the 

number of lethargic bees increased to 14%. Mortality was 2, 6, 6, 4 and 30% in the 16.4, 32.8, 

65.5, 131 and 262 μg a.i./bee treatment groups, respectively. The 48-hour acute contact LD50

was >262 μg a.i./bee and the NOAEL was 65.5 μg a.i./bee, based on sub-lethal effects. 

The acute contact and oral toxicity of a 22% ammonium salt formulated product (MRID 

44766401; Acceptable (contact), Supplemental (oral)) to honey bees were tested in the 

laboratory. In the 48- hour acute contact test, bees were exposed to the formulation administered 

topically to the thorax, at an application rate of 0 (control), 6.25, 12.5, 25, 50 and 100 μg a.i./bee, 

while in the oral test, bees were exposed to the formulation by feeding at an intake rate of 7.36, 

13.56, 29.11, 59.21 and 108.94 μg a.i./bee. In the contact test, no sub-lethal effects were 

observed in the control or in the treatment groups. Mortality was 0% in the control and nominal 

6.25, 12.5 and 25 μg a.i./bee treatment groups and 8 and 14% in the nominal 50 and 100 μg 

a.i./bee treatment groups, respectively. The resulting contact NOAEL and LD50 values were 50 

and >100 μg a.i./bee, respectively. In the oral test, no sub-lethal effects were observed in the 

control or treatment groups. At the highest dose of 108.94 μg a.i./bee, only 4% of the bee died. 

The resulting oral NOAEC and LC50 values were 108.94 and >108.94 μg a.i./bee, respectively. 

POTASSIUM SALTS OF FATTY ACIDS 

The acute contact toxicity of a 52.8% potassium salt formulated product (MRID 42806001; 

Acceptable) to honey bees (Apis mellifera) was tested in the laboratory. In the 48-hour acute 

contact test, bees were exposed to the formulation administered topically to the thorax, at an 

application rate of 0 (negative and solvent controls), 0.8, 1.6, 3.3, 6.6 and 13 μg a.i./bee. 

Immobility was observed in one bee in the nominal 0.8 μg a.i./bee treatment group and in two 

bees in each of the 1.6 and 13 μg a.i./bee treatment groups the first 2 hours following application 

of the formulation. No sub-lethal effects were observed. Mortality was 0% in the controls and 

nominal 0.8, 3.3 and 6.6 μg a.i./bee treatment groups and 4% in the nominal 1.6 ad 13 μg a.i./bee 

treatment groups, yielding 48-hour acute contact LD50 and NOAEL values of >13 and 13 μg 

a.i./bee, respectively. 
98 

The acute contact toxicity of a 19.9% potassium salt formulated product (MRID 43042801; 

Acceptable) to honey bees (Apis mellifera) was tested in the laboratory. In the 48-hour acute 

contact test, bees were exposed to the formulation administered topically to the thorax, at an 

application rate of 0 (negative and solvent controls), 0.3, 0.6, 1.3, 2.5 and 5 μg a.i./bee. No 

mortality was observed in the negative control and solvent control groups. Four bees appeared 

lethargic on day 0 in the negative control group, all other control bees appeared normal 

throughout the test. Mortality in the treatment groups ranged between 0 and 4%. On day 0, one 

bee was lethargic in the highest dose. All surviving bees were normal in appearance and behavior 

throughout the test. The 48-hour acute contact LD50 and NOAEL values were >5 and 5 μg 

a.i./bee, respectively, based on lack of mortality and sub-lethal effects. 

The acute contact toxicity of a 40% potassium salt formulated product (MRID 43173604; 

Acceptable) to honey bees (Apis mellifera) was tested in the laboratory. In the 48-hour acute 

contact test, bees were exposed to the formulation administered topically to the thorax, at an 

application rate of 0 (negative and solvent controls), 0.6, 1.2, 2.5, 5 and 10 μg a.i./bee. None of 

the bees died in the negative control group; however, 6% mortality was observed in the solvent 

control group. Mortality in the treatment groups ranged between 0 and 4%. The 48-hour acute 

contact LD50 and NOAEL values were >10 and 10 μg a.i./bee, respectively, based on lack of 

mortality and sub-lethal effects. 

The acute contact and oral toxicity of a 50.5% potassium salt formulated product (MRID 

45060901; Acceptable (contact), Supplemental (oral)) to honey bees were tested in the 

laboratory. In the 48- hour acute contact test, bees were exposed to the formulation administered 

topically to the thorax, at an application rate of 0 (control), 6.25, 12.5, 25, 50 and 100 μg a.i./bee, 

while in the oral test, bees were exposed to the formulation by feeding at an intake rate of 6.15, 

10.7, 24.32, 48.72 and 96.04 μg a.i./bee. In the contact test, mortality was 0% in the control and 

nominal 6.25, 12.5, 25 and 50 μg a.i./bee treatment groups and 10% in the nominal 100 μg 

a.i./bee treatment group. The resulting contact NOAEL and LD50 values were 50 and >100 μg 

a.i./bee, respectively. In the oral test, mortality was 8% in the control and 6, 18, 8, 14 and 20% in 

the nominal 6.15, 10.7, 24.32, 48.72 and 96.04 μg a.i./bee treatment groups, respectively. The 

resulting oral NOAEC and LC50 values were 25 and >96.04 μg a.i./bee, respectively. 

Terrestrial Plants, Seedling Emergence and Vegetative Vigor 

Terrestrial plant studies are required for all terrestrial outdoor pesticides. Tier II terrestrial plant 

toxicity studies were conducted to establish the toxicity of the ammonium (Table C.10) and 

potassium salt formulated products (Tables C.11 and C.12) to non-target terrestrial plants which 

was tested at doses lower than the maximum labeled application rates of 103.8 and 205 lb a.i./A 

for ammonium and potassium salts respectively. The recommendations for seedling emergence 

and vegetative vigor studies are for testing of (1) six species of at least four dicotyledonous 

families, one species of which is soybean (Glycine max), and the second of which is a root crop, 

and (2) four species of at least two monocotyledonous families, one of which is corn (Zea mays). 

AMMONIUM SALTS OF FATTY ACIDS 

For seedlings and young plants exposed to ammonium salt formulated products (Table C.10), 

seedlings at 100 lb a.i./A were not affected while active-growing monocotyledonous and 

dicotyledonous species were mostly affected. The seedling emergence EC25s were >100 lbs 
99 

a.i./A for all monocotyledonous and dicotyledonous species tested and would be used as a 

screening-level endpoint to assess risk to non-listed seedling, as well as it corresponding 

NOAEC of 100 lb a.i./A to assess risk to listed plants. 

In the vigor studies, dry weight was most affected in corn, oat, bean, oilseed rape and soybeans, 

while shoot length was most affected in cucumber, radish and tomato. No effects were seen in 

active-growing onion and ryegrass when exposed to ammonium salt formulated products. The 

most sensitive monocotyledonous species was corn, based on dry weight, with EC25 and NOAEC 

values of 6.2 and 1.5 lb a.i./A and would be used to assess risk to non-listed and listed 

monocotyledonous plants, respectively. The most sensitive dicotyledonous species was tomato, 

based on shoot length, with EC25 and EC05 values of 2.2 and 1.1 lb a.i./A and would be used to 

assess risk to non-listed and listed dicotyledonous plants, respectively. 

Table C.10. Summary of Tier II Seedling Emergence and Vegetative Vigor Results for an 

Ammonium Salt Formulated Product 

Vegetative Vigor* Seedling Emergence** 

Species Endpoint NOAEC/[EC05] EC25 Endpoint NOAEC EC25

Corn Dry weight 1.5 6.2 None 100 >100 

Oat Dry weight 6.3 9.8 None 100 >100 

Onion None 6.3 >6.3 None 100 >100 

Ryegrass None 6.3 >6.3 None 100 >100 

Bean Dry weight 6.3 27 None 100 >100 

Cucumber Shoot length 1.3 6.6 None 100 >100 

Oilseed Rape Dry weight 1.5 2.9 None 100 >100 

Radish Shoot length 0.094 5.8 None 100 >100 

Soybean Dry weight 1.5 4.4 None 100 >100 

Tomato Shoot length 1.1 2.2 None 100 >100 

* 21.85% a.i ammonium salts of fatty acids; MRID 48402205, Martin. 2011. Measured concentrations for tomato 

were <LOQ (<0.0015, control), 0.023, 0.094, 0.36, 1.5, and 6.3 lb a.i./A. For corn, oilseed rape, cucumber, onion, 

ryegrass, and radish, measured concentrations were <LOQ (<0.0015, control), 0.094, 0.36, 1.5, 6.3, and 22 lb a.i./A. 

For bean, oat, and soybean, measured concentrations were <LOQ (<0.0015, control), 0.36, 1.5, 6.3, 22, and 94 lb 

a.i./A. 

** 21.85% a.i ammonium salts of fatty acids; MRID 48402204, Martin. 2011.

POTASSIUM SALTS OF FATTY ACIDS 

Results indicate the plants at the 3-leaf stage (young plants) exposed to potassium salts were 

more sensitive to potassium salt formulated products than seedlings (Tables C.11 and C.12. 

Monocotyledonous and dicotyledonous seedlings and active-growing monocotyledonous species 

were generally not inhibited 25% or more to potassium salt formulated products at the maximum 

doses (62 or 68 lb a.i./A). The only reliable dicotyledonous seedling was radish, the EC25 and 

NOAEC values were 53.9 and 3.9 lb a.i./A based on reduced height and would be used as 

screening-level endpoints to assess risk to non-listed and listed dicotyledonous seedlings, 

respectively. For monocotyledonous seedlings, the most sensitive species was ryegrass based on 

significant reductions in survival and emergence, the EC25 and NOAEC values were >62.34 and 

31.17 lb a.i./A and would be used to assess risk to non-listed and listed monocotyledonous 

seedlings, respectively.

Dry weight was the most sensitive endpoint in the vegetative vigor studies exposed to potassium 

salt formulated products. The most sensitive monocotyledonous species was corn, based on dry 
100 

weight, with EC25 and NOAEC values of 5.91 and 4.24 lb a.i./A and would be used to assess risk 

to non-listed and listed monocotyledonous plants, respectively. The most sensitive 

dicotyledonous species was oilseed rape, based on dry weight, with EC25 and EC05 values of 18.5 

and 4.38 lb a.i./A and would be used to assess risk to non-listed and listed dicotyledonous plants, 

respectively. 

Table C.11. Summary of Tier II Seedling Emergence and Vegetative Vigor Results for a Potassium 

Salt Formulated Product 

Vegetative Vigor* Seedling Emergence** 

Species Endpoint NOAEC/[EC05] EC25 Endpoint NOAEC/[EC05] EC25

Corn Dry weight 4.24 5.91 None 68.57 >68.57 

Onion None 68.08 >68.08 None 68.57 >68.57 

Ryegrass None 68.08 >68.08 None 68.57 >68.57 

Oat None 68.08 >68.08 None 68.57 >68.57 

Bean Dry weight 8.104 20.72 None 68.57 >68.57 

Cucumber Dry weight 16.21 23.05 Emergence 

and 

Survival 

16.83 23.8A

Oilseed 

Rape 

Dry weight [4.38] 18.50 None 68.57 >68.57 

Radish Dry weight 16.21 57.27 None 68.57 >68.57 

Soybean Dry weight 16.21 30.55 Emergence 

and 

Survival 

[4.1] 43.79 A

Tomato Dry weight 16.21 21.73 None [0.0000021]*** >68.57 

* 46.8% a.i potassium salts of fatty acids; MRID 48402302, Martin. 2011. 

** 46.8% a.i potassium salts of fatty acids; MRID 48402301, Martin. 2011. 

*** Result is not reliable, as it is well below tested doses.

A Toxicity value should be interpreted with caution as the 95% confidence intervals appear unreliable. 

Table C.12. Summary of Tier II Seedling Emergence and Vegetative Vigor Results for a Potassium 

Salt Formulated Product 

Vegetative Vigor* Seedling Emergence** 

Species Endpoint NOAEC/[EC05] EC25 Endpoint NOAEC EC25

Corn None 68.57 >68.57 None 62.34 >62.34 

Onion None 68.57 >68.57 None 62.34 >62.34 

Ryegrass Shoot length 31.79 NC Emergence 

and 

Survival 

31.17 >62.34 

Oat Dry weight 16.21 >68.57 None 62.34 >62.34 

Bean Shoot length [39.3] 49.8 Height 31.17 >62.34 

Cucumber Shoot length [2.3]A 47.7 None 62.34 >62.34 

Oilseed Rape None [NC] NC Weight 15.58 >62.34 

Radish None 68.57 >68.57 Height 3.9 53.9 

Soybean None 68.57 >68.57 None 62.34 >62.34 

Tomato Dry weight 31.79 32.6 None 62.34 >62.34 

* 50.8% a.i potassium salts of fatty acids; MRID 48608703, Martin. 2006. 

** 50.8% a.i potassium salts of fatty acids; MRID 48608704, Martin. 2011. 

NC – The ECx or/and 95% confidence intervals appear unreliable. A Toxicity value should be interpreted with caution as the 95% confidence intervals appear unreliable.