# Environmental Fate and Ecological Risk Assessment Preliminary Problem Formulation in Support of Registration Review of Pyrethrins

DP Barcode D391619
PC Code 069001

Case No. 2580



## November 30, 2011



# Environmental Fate and Effects Division Office of Pesticide Programs U.S. Environmental Protection AgencyPrepared by: Amanda Solliday, Biologist José L. Meléndez, Chemist

Secondary Review: Keith Sappington, Senior Advisor Mah T. Shamim, Ph.D., Chief

Environmental Risk Branch V

23 Table of Contents

1. Purpose .................................................................................................................... ................ 4
2. Problem Formulation ........................................................................................................ ...... 5 2.1 Nature of Regulatory Action .............................................................................................. .. 5
2.2. Previous Risk Assessments ................................................................................................ .. 6
3. Stressor Source and Distribution ........................................................................................... . 9
3.1. Mechanism of Action ..................................................................................................... ... 16 3.2. Overview of Pesticide Usage ............................................................................................ 17 3.3. Environmental Fate and Transport .................................................................................... 30 4. Receptors................................................................................................................... ............ 35 4.1. Aquatic and Terrestrial Effects ......................................................................................... 35
4.2. Incident Database Review................................................................................................. 43 4.3. Ecosystems Potentially at Risk ......................................................................................... 45 5. Assessment Endpoints ....................................................................................................... ... 35 6. Conceptual Model .................................................................................................... .......... 46 6.1. Risk Hypothesis ........................................................................................................ ....... 46 6.2. Conceptual Diagram ..................................................................................................... ... 47 7. Analysis Plan ....................................................................................................... .............. 52
7.1. Stressors of Concern .................................................................................................... ..... 53 7.2. Measures of Exposure .................................................................................................... ... 53
7.3. Measures of Effect ...................................................................................................... ...... 58 7.4. Integration of Exposure and Effects ................................................................................. 59
7.5. Deterministic and Probabi listic Assessment Methods ...................................................... 59 7.6. Endangered Species Assessments ..................................................................................... 59 7.7. Drinking Water Assessment ............................................................................................. 6 0 7.8 Endocrine Disruption Screening Program ........................................................................ 60 7.9. Preliminary Identifica tion of Data Gaps ........................................................................... 61
7.9.1. Fate .................................................................................................................. ........... 61
7.9.2 Effects ................................................................................................................ ......... 65
8. References ................................................................................................................ ................ 70 9. Bibliography .............................................................................................................. .............. 70 Appendix A. PRD Data Reque st Justification Tables ................................................................ 80 Appendix B. Pyrethrins Down-the-Drain Risk Assessment ....................................................... 844 1. Purpose

The purpose of this problem formulation is to provide the foundation for the ecological risk assessment being conducted for the registered us es of pyrethrin. As such, it articulates the purpose and objectives of the risk assessment, eval uates the nature of the problem, and provides a plan for analyzing the data and characterizi ng the risk (USEPA, 1998). Additionally, this problem formulation is intended to identify data gaps, uncertainties and potential assumptions
needed to address those uncertainties in charact erizing the ecological risk associated with the registered uses of pyrethrin.

Pyrethrin (also refered to in th is document as pyrethrins; PC Code 069001) is a broad-spectrum insecticide used in four major sectors: agricultural settings, commercial/industrial/institutional/ food & non-food/mosquito abatement, domestic home and garden, and pet care. The pyrethrins are a mixture of naturally occurring ins ecticides derived from the flowers of Chrysanthemum cinerariaefolium and Chrysanthemum cineum . The six individual pyrethrins are pyrethrin 1, pyrethrin 2, cinerin 1, cinerin 2, ja smolin 1, and jasmolin 2. The technical grade active ingredient (FEK-99) is commonly referred to as pyrethrum extract, which is the sum of pyrethrins I (the esters of chrysanthemic acid - pyrethrin 1, cinerin 1 and jasmolin 1) and pyrethrins II (the esters of pyrethric acid - pyrethrin 2, ci nerin 2, and jasmolin 2), and this mixture constitutes 45 to 55% of pyrethrum extract. In additi on to pyrethrins, the extract cont ains “23-25% other phytochemical extracts containing triglyceride oi ls, terpenoids, and carotinoid plan t colours. The extracts usually contain 20-25% light isoparaffi ns and 3-5% butylated hydroxytoluene, which may be added during and after processing, respec tively, for extraction or as antio xidants” (Solecky 1999). All six pyrethrins have the same backbone molecular stru cture with different substituents at two sites.
Since all the structures at th e two sites are similar, they are expected to have similar environmental fate properties. The produc t PYRENONE® Crop Spray, a formulation that contains pyrethrins (6.0%), piperonyl butoxide (60.0%) and inert ingredie nts (34.0%), was used as a test material in many of the ecological eff ects laboratory studies. For the structure of the individual pyrethrins and further identification information, refer to Figure 3-2 and Table 3.1

.

There are many other formulation types, such as aerosol, combustible coil, dust, emulsifiable concentrate, ready to use li quid, shampoo, and wettable powder. According to the Chemical Profile for pyrethrins written by the Biological and Economic Analysis Division, “Application methods in agricultural and non-agricultural uses (based on the Reregistra tion Eligibility Decision [RED]) are diverse, and include: aerosol can, mist blower, metered release devices, total release aerosol, fixed wing aircraft, helic opter, truck-mounted ultra low volume (ULV) equipment, cold aerosol generator, hand held sprayers (high or low pressure handwands), thermal/cold/ULV fogging equipment, conven tional dusting equipment ( e.g. , power duster, bulb duster, shaker can), outdoor misting systems, and irrigation systems (USEPA 2011).

Of these, power dusting was banned by the RED due to inability to assess risk scenarios. However, dust applications to carpets are allowe d as spot treatments only. All other application methods are still label uses. However, due to human health risk concerns, several risk mitigation measures (such as limits on the number of applica tions per year or individual area treated) were imposed by the RED for three general application methods: broadcast dusts applied to carpets,5 indoor metered release devices, and out door residential misting systems.

As stated in BEAD’s Chemical Profile for Pyrethrins, “[T]he Insecticide Resistance Action Committee (IRAC), comprised of t echnical personnel from various large agrochemical and public health companies, classifies pyrethrin as a member of the Mode of Action Group 3 (subgroup 3A). This group of insecticides acts as sodium channel modulators, thus causing disruption of nerve impulses in the target insects (USEPA 2011).

Like other compounds derived from the chemical st ructure of pyrethrum, it is most toxic to the target pest on contact, and has a quick “knoc kdown” effect (Doull 1976). Pyrethrin is sometimes formulated with a synergist compound, usually pi peronyl butoxide, also known as PBO, or MGK264, to extend its active life and increase its toxic effect on target insects (Jones 1998).”

For agriculture uses, maximum seasonal rates ar e 0.50 lb a.i./A, and for all crops, the maximum number of pyrethrin applications per season is 10 at the maximum single application rate of 0.050 lb a.i./A (from the pyrethrins Master Label). Py rethrin may be applied year-round; thus, in some regions of the United States more than one season per year are possible. Because target species could develop resistance to pyrethrins, it appears that multiple seasons at the maximum seasonal rate are unlikely. According to BEAD’s Chemical Profile for pyrethrin, “Based on private market pesticide usage data from 1998-2010, the annual tota l agricultural usage av eraged approximately 2,000 pounds active ingredient for 123,000 acres (GfKynetic, 1998-2010).” Furthermore, the usage data indicates that the consumer indoor use ranged from 53,000 to 113,000 lbs active ingredient from 2000-2005, which indicates that non-agricultural use exceeds that of use on agricultural crops. Pyrethrin ma y be used in a wide variet y of crop and non-crop sites, ornamentals, lawns, etc. The chemical also has other FIFR A uses, such as applications to livestock (cattle, pigs, goats, horses and various others), pets (birds, dogs, cats, guinea pigs and various others) and in commercia l animal housing sites (such as pet stores and zoos). Pyrethrin can also be used on human clothing (for insect and mold/ mildew contro l), including clothing, outerwear clothing, in stor age clothing and woolens.

2. Problem Formulation

2.1. Nature of Regulatory Action

This report is the Environmental Fate and Effect s Division’s (EFED) Probl em Formulation for the Registration Review of pyrethrins. Previous risk assessments were completed for the use of this chemical, which serve as the basis for this document.

The Food Quality Protection Act (FQPA) of 1996 mandated the EPA to implement registration review ( http://www.epa.gov/oppsrrd1/registration_review/ ). All pesticides di stributed or sold in the United States generally must be registered by th e EPA. The decision to register a pesticide is
based on the consideration of scientific data and other factors showing that it will not cause unreasonable risks to human health, workers, or the environment when used as directed on product labeling. In addition, it must not be expected to caus e unreasonable adverse effects to human health through the dietary and residentia l routes of exposure under the Federal Food Drug6 and Cosmetic Act (FFDCA). The registration revi ew program is intended to ensure that, as the ability to assess risk evolves and as policies a nd practices change, all registered pesticides continue to meet the statutory standard of no unreasonable advers e effects to human health and the environment. Changes in science, public po licy, 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, Fungicid e and Rodenticide Act (FIFRA), the Agency is conducting an evaluation to determine whether pyr ethrin continues to meet the FIFRA standard for registration. This problem formulation for the environmental fa te and ecological risk assessment chapter, in support of the registration review, is intended for the initi al docket opening the public phase of the review process.

2.2. Previous Risk Assessments an d Scientific Advisory Panels

The most recent review performed for the pyrethr ins was the national-leve l EFED chapter of the Reregistration Eligibility Decision Do cument (EFED RED, dated April 4 th 2007; DP Barcode: D338495, USEPA 2007). The review indicated risk concerns for freshwater and estuarine/ marine organisms, including benthic organsims. For the agricultural uses, model generated exposure values suggested that maximum rates can result in acute ri sk to fish and aquatic invertebrates (freshwater and estuarine/ marine) with triggers that incl uded restrictive use and endangered species concern. Although concern for estuarine/ marine endangered invertebrate was triggered, EFED noted there were no listed spec ies under this category. However, it appears that at the present time there are listed estuarine/ ma rine species. Evaluating chronic risk from this exposure scenario showed that the LOC tri ggers were exceeded for estuarine/ marine invertebrates, while fish (freshwater and estuar ine/ marine) and freshwat er invertebrates were
found not to be at chronic risk from pyrethrin exposure in the wa ter column. Evaluation of four crop scenarios using the TGAI (ID potatoes, PA tomatoes, CA onions, OR snap beans) suggested
that LOCs for freshwater and estuarine/marine fish and invertebrates should not be exceeded if the typical application rate is used.

EFED also addressed potential aquatic risk from the PBO formulation at the maximum and typical rates for a pyrethrin. In th is case, the Agency only evaluated acute exposure to aquatic organisms. Risk quotients were calculated usi ng the technical grade active ingredient for the agricultural uses and formul ated product (PYRENONE® Crop Spray, EPA Reg. No. 432-1033) for the mosquito abatement uses. However, EFED also calculated potential risk from PBO formulation use on agricultural crops, which s howed that acute risk to freshwater and
estuarine/marine fish and invertebrates could increase by 2-7x for fres hwater and estuarine/
marine fish and 10x for estuarine/marine inve rtebrates based on the e nhanced toxicity of pyrethrins in the presence of the synergist PBO. However, the results obtained using the typical end use product with the synergist at the typical application rate resu lted in reduction of the risk to aquatic organisms (freshwater and estuarine/ marine fish and freshwater i nvertebrates), but this reduction in exposure still presented the potential for acute high, acute restrictive, and chronic risk7 to estuarine/marine invertebrates species.

Evaluation of the mosquito abatement applications , at the maximum rate showed that there did not appear to be the potential for acute risk to freshwater fish and invert ebrates or esrtuarine/ marine fish but there was the potential for acu te LOCs being exceeded for estuarine/ marine invertebrates. However, this risk to estuarine/ma rine invertebrates appeared to be eliminated if the boom height is set at 150 ft and a D v0.5 droplet size at 40 μm (a D v0.5 value is the droplet size over which half of the volume of the droplets is above that value and half of the volume of the droplets is below that value). The Agency also evaluated the typical rate and found that potential
acute risk to estuarine/marine invertebrates coul d be eliminated with a boom height of 75ft and a

D v0.5 50 μm droplet size.

The Agency also evaluated the pharmacological uses of pyrethrin using the “Down-the-Drain” module of the Exposure and Fate Assessment Sc reening Tool (E-FAST) model and found that aquatic LOCs were not exceeded for freshw ater or estuarine/marine organisms.

In the RED risk assessment, the Agency did not fi nd acute and chronic risks to listed or non-listed mammalian and avian species. Chronic avian data was not available, and risks were estimated using the results from a sub-acute dietar y study. Although the Agency did not conduct a quantitative risk assessment for beneficial insect s at the time, toxicity studies with honey bees show that pyrethrins are highly to xic on an acute contact basis. This suggests that pyrethrins are toxic to nontarget beneficial insects, as well as listed insect species.

2009 Scientific Advisory Panel OPP presented a “Proposed Common Mechanis m Grouping for the Pyrethrins and Synthetic Pyrethroids” to a FIFRA SAP in June 2009. OPP proposed two subgroups based on Type I or Type II effects related to sodium current tails and neurobehavioral impact, with esfenvalerate and fenpropathrin showing symptoms of both types. The panel agreed with OPP and indicated that
substances with mixed characteri stics could be included in both groups (see p. 18 of SAP minutes, USEPA 2009). The natural pyrethrins are Type I pyrethroid insecticides, with no cyanosubstitution in the alpha -position. This mechanism of action assessment was performed by HED/OPP and presented to the SAP to determine if a cumulative assessment is required for the synthetic pyrethroids. Information on the SAP is available in the doc ket (with non-copyright
material available at http://www.regulations.gov ) under EPA-HQ-OPP-2008-0489.

EFED does not currently conduct cumulative ecologi cal risk assessments for several reasons. Specifically, the Division does not currently ha ve the methodology to conduct similar cumulative risk assessments for all of the (non-human) biolog ical entities for which EFED has responsibility. In addition to addressing the toxicological aspects of the cumulative effects of multiple pyrethroids to multiple biological entities, a cu mulative ecological risk assessment would likely require consideration of exposure at a watershed scale in order to incorporate spatia l and temporal variability in pyrethroid applications into cumula tive exposure assessment. EFED does not have the modeling tools developed for conducting this type of assessment. However, EFED will consider open literature, currently available models and other lines-of-evidence ( e.g. , monitoring8 data) as available, to address the potential for cu mulative effects of pyrethroids and pyrethrins in the risk description of the ecological risk assessment for pyrethrin.

National Water Quality Assessment (NAWQA) The pyrethrins are not among the constituents monitored by the National Water Quality Assessment (NAWQA), maintained by the U.S. Geological Survey.

Aquatic Life Criteria and Aquatic Life Benchmarks The Clean Water Act requires the Agency to publish water quality criteria that accurately reflect the latest scientific knowledge on the kind and ex tent of all identifiable effects on health and welfare which might be expected from the presen ce of pollutants in any body of water, including ground water. While these recommended criteria do not, in themselves, impose any requirements,
states and authorized tribes can use them to develop water quality stan dards. US EPA Aquatic Life Ambient Water Quality Criteria documen t has not been published for pyrethrin (at http://www.epa.gov/waterscience/criteria/ accessed 05/09/11).

For pyrethrin, OPP has not published aquatic life be nchmarks for freshwater species, based on the most sensitive species from the most recent ri sk assessments (refer to the following site http://www.epa.gov/oppefed1/ecorisk_ders/a quatic_life_benchmark.htm#benchmarks accessed 05/09/11).

Impaired Water Bodies Pyrethrin is not individually iden tified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_na tion_cy.cause_detail_303d ?p_cause_group_id=885 (accessed 10/24/11). However, the pyrethroids (which are pyrethrin-like compounds, and could involve natural pyrethrins) as a group have been identified as a cause for impairment for three water bodies in Central Valley, Calif ornia: Del Puerto Creek, Ingram Creek Site (from confluence with Hospital Creek to Highway 33 crossing) and second Ingram Creek Site (from confluence with San Joaquin River to confluence with Hosp ital Creek). Additional bodies of water were
evaluated and included into the list of impaired bodies of water by October 2011 (see http://www.waterboards.ca.gov/water_issu es/programs/tmdl/integrated2010.shtml

, http://www.swrcb.ca.gov/rwqc b5/water_issues/tmdl/impaire d_waters_list/303d_list.shtml and http://www.epa.gov/region9/water/tmdl/303d-pdf/Final-DecisLtrEnclosResponsSumCA2008-10- 303d.pdf accessed 10/24/11). The 2010 303(d) list for California contains 10 additional streams due to pyrethroids in the sediments. EFED will include relevant information on 303(d) listings in the final ecological risk assessment as appropriate.

No Total Maximum Daily Load (TMDL) criteria have been developed sp ecifically for pyrethrin, based on information provided at http://iaspub.epa.gov/tmdl_waters10/attains_ nation.tmdl_pollutant_de tail?p_pollutant_group_id= 885&p_pollutant_group_name=PESTICIDES (accessed 10/24/11). It appears that a TMDL was established for pyrethroids and specifically for bifenthrin (Rio de Santa Clara/Oxnard Drain No. 3). More information on impaired wa ter bodies and TMDLs can be found at http://www.epa.gov/owow/tmdl/ . The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards in Appendix A of9 the OPP Standard Operating Procedure: Inclus ion of Impaired Water Body and Other Water Quality Data in OPP’s Registration Revi ew Risk Assessment and Management Process (at http://www.epa.gov/oppsrrd1/regist ration_review/water_quality_sop.htm ), in order to ensure they can be used quantitatively or qualitati vely in pesticide risk assessments.

3. Stressor Source and Distribution

Pyrethrins are nonvolatile hydrocar bons produced by certain species of the chrysanthemum plant (genus Chrysanthemum ) and have been used as insecticides since the 1800s. The plant species
with the most toxic content that can be e fficiently used for industrial purposes are C. cinerariaefolium and C. coccineum , which are grown mainly in Au stralia and East Africa. The active insecticidal components are collectively k nown as pyrethrins and consist of six esters. Although the ground flowers can be us ed as a dust, a more concentrated and efficacious pyrethrin product is possible through solvent extraction. Py rethrin-containing dusts and extracts usually have an active ingredient cont ent of about 30%. However, afte r filtration and reextraction the concentration can reach 90-100% (Matsumura 1985). These compounds are contact poisons which can quickly penetrate the neural syst em. Although the pyrethrin s have an effective “knockdown” action (induction of temporary paralysi s) they do not necessarily have high killing properties by themselves. These compounds are moderately persistent under certain environmental conditions but are quickly metaboli zed under other conditions such as in the presence of sunlight (photolysis). In order to delay the metabolic action (inhibition of microsomal enzymes) so that a lethal dose is assured, organophosphates, carbam ates, or synergists (such as piperonyl butoxide) may be added to the pyr ethrins (Ecobichon and Donald, 1991). Pyrethrin compounds have been used primarily to control human lice, mosquitoes, cockroaches, beetles, and flies. Some pyrethrin compounds used to c ontrol insects in horticult ural crops, are only 0.3% to 0.5% pyrethrins, and are used at rates of up to 50 lb/A. Other pyrethrin compounds may be used in grain storage and in poultry pens a nd on dogs and cats to control lice and fleas.

Natural pyrethrins have their limitations for use on a large scale for agricultural purposes because of their cost and instability in sunlight. Therefore, in recent decades, many man-made pyrethrinlike compounds were developed and are referred to as synthetic pyrethroids. These compounds are more stable in sunlight (due to lower reac tivity of side-chains) a nd are generally effective against most agricultural insect pest s when used at very low rates.

The formulated products of pyrethr ins usually contain a synergist, such as piperonyl butoxide, or MGK-264. These compounds enhance the insecticid al activity of pyrethrin. The Agency does not routinely include, in its screening risk assessments, an evaluation of more than one active ingredient. In the case of product formulations of active ingredients, each active ingredient is subject to an individual risk a ssessment for regulatory decision. It is noted, however, that some formulations of pyrethrin cont ain up to 60% PBO, with only about 5 to 6% pyrethrins. Table 3.1 provides some identification inform ation for pyrethrins, also, refe r to its general structure in Figures 3-1 and 3-2

.Figure 3-1. The general structure a nd stereochemistry of the pyrethrins

R = -CH 4 (for cinerin), -CH 3 CH 4 (for jasmolin) or -CH=CH 2 (for pyrethrin)
R’= -CH 3 (for pyrethrins I) -CO 2 CH 4 (for the pyrethins II)

The six individual pyrethrins are pyrethrin 1, pyr ethrin 2, cinerin 1, cinerin 2, jasmolin 1, and jasmolin 2. These compounds are esters of two carboxylic acids (chrysanthemic acid and pyrethric acid) and three cyclopentenolones (pyr ethrolone, cinerolone, and jasmolone). The technical grade active ingredient (FEK-99) is comm only referred to as pyrethrum extract, which is the sum of pyrethrins I (the esters of chrysanthe mic acid - pyrethrin 1, cinerin 1, and jasmolin 1) and pyrethrins II (the esters of pyrethric acid - pyrethrin 2, cinerin 2, and jasmolin 2), also called "the pyrethrins", and this mixture constitutes 45 to 55% of pyrethrum extract. In the United States, the pyrethrum extract is standardized as 45-55% w/w total pyrethrins. The typical proportion of Pyrethrins I to II is 1:14, while the ratio of pyrethrins: cynerins: jasmolins is 71:21:7 (Tomlin 1997).

10Figure 3-2. Specific structures of each of the pyrethrins

Table 3.1. Identification information for pyrethrins

PARAMETER VALUE(s) SOURCES

Nomenclature of Pyrethrins (IUPAC Names) pyrethrin 1 : (Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2- enyl (1R,3R)-2,2dimethyl-3-(2-methylprop-1-enyl) cyclopropanecarboxylate pyrethrin 2 : (Z)-(S)-2-methyl-4-oxo-3-(penta-2,4-dienyl)cyclopent-2- enyl (E)-(1R,3R)-3-(2methoxycarbonylprop-1-enyl)-2,2- dimethylcyclopropanecarboxylate
cinerin 1 : (Z)-(S)-3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl (1R,3R)-2,2-dimethyl-3(2-methylprop-1-enyl) cyclopropanecarboxylate
cinerin 2 : (Z)-(S)-3-(but-2-enyl)-2-methyl-4-oxocyclopent-2-enyl

(E)-(1R,3R)-3-(2methoxycarbonylprop-1-enyl)-2,2- USEPA 2006b

1112 Table 3.1. Identification information for pyrethrins

PARAMETER VALUE(s) SOURCES
dimethylcyclopropanecarboxylate jasmolin 1 : (Z)-(S)-2-methyl-4-oxo-3-(pent-2-enyl)cyclopent-2-enyl (1R,3R)-2,2-dimethyl-3(2-methylprop-1- enyl)cyclopropanecarboxylate jasmolin 2 : (Z)-(S)-2-methyl-4-oxo-3-(pent-2-enyl)cyclopent-2-enyl

(E)-(1R,3R)-3-(2methoxycarbonylprop-1-enyl)-2,2- dimethylcyclopropanecarboxylate

Nomenclature of Pyrethrins (CAS Names) pyrethrin 1 :(1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienylcyclopenten1-yl (1R,3R)-2,2dimethyl-3-(2-methyl-1-propenyl) cyclopropanecarboxylate pyrethrin 2 : (1S)-2-methyl-4-oxo-3-(2Z)-2,4-pentadienyl-2- cyclopenten-1-yl (1R,3R)-3-[(1E)3-methoxy-2-methyl-3-

oxo-1-propenyl]-2,2-dimethylcyclopropanecarboxylate
cinerin 1 : (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-2,2-dimethyl3-(2-methyl-1-propenyl) cyclopropanecarboxylate
cinerin 2 : (1S)-3-(2Z)-2-butenyl-2-methyl-4-oxo-2-cyclopenten-1-yl (1R,3R)-3-[(1E)-3methoxy-2-methyl-3-oxo-1-propenyl]- 2,2-dimethylcyclopropanecarboxylate jasmolin 1 : (1S)-2-methyl-4-oxo-3-(2Z)-2-pentenyl-2-cyclopenten-1- yl (1R,3R)-2,2-dimethyl3-(2-methyl-1-

propenyl)cyclopropanecarboxylate jasmolin 2 : (1S)-2-methyl-4-oxo-3-(2Z)-2-pentenyl-2-cyclopenten-1- yl (1R,3R)-3-[(1E)-3methoxy-2-methyl-3-oxo-1- propenyl]-2,2-dimethylcyclopropanecarboxylate USEPA 2006b

PC Code 069001 USEPA 2006b

Case Number 2580 USEPA 2006b

CAS Reg. Nos. 8003-34-7 Pyrethrum, 121-21-1 pyrethrin 1, 121-29-9 pyrethrin 2, 25402-06-6 cinerin 1,

121-20-0 cinerin 2, 4466-14-2 jasmolin 1, 1172-63-0 jasmolin 2 USEPA 2006b

Molecular Formulas Various as follows:
C 21 H 25 O 3, C 21 H 25 O 5, C 20 H 25 O 3, C 22 H 30 O 5

, C 21 H 28 O 3 , C 22 H 28 O 5 USEPA 2006b

Molecular Weights 328.4 g/mol pyrethrin 1 372.4 g/mol pyrethrin 2 316.4 g/mol cinerin 1 360.4 g/mol cinerin 2 330.5 g/mol jasmolin 1 357.7 g/mol jasmolin 2 USEPA 2006b

The structures of pyrethrins from the chemical’s data sheet accessed 05/10/2011 and available at http://www.alanwood.net/pesticides/pyrethrins.html

.

The laboratory environmental fate studies conducted for the pyrethrins were based on the data13 obtained for pyrethrin 1, which was chosen as a surr ogate for all the six pyrethrins. This selection appears to be appropriate since pyrethrin 1 is the pyrethrin with the highest abundance in the pyrethrum extract ( e.g. , see Essig and Zhao 2001). The follo wing conclusions were derived for these compounds: Pyrethrins are considered to be persistent in certain environments and short lived in other environments. Hydrolysis under alkaline conditions is an important route of dissipation for pyrethrins in wate r (half-life at pH 9 range 14-17 days); however, this reaction appears to be relatively slow unde r neutral or acidic conditions (p H 5 and 7). Pyrethrins quickly photodegrade in shallow clear water. Pyrethrins adsorb strongly to soil surfaces and are generally considered to have a relatively low mobility in soils (mean K F = 301.5 L/kg); therefore, the potential to leach into groundwater is considered low. They could reach surface water via spray drift or runoff events accompanied by erosion wher e they quickly adsorb to suspended solids in the water column, and partition into the sediment. Sediments are likely to be an environmental sink for any non-degraded pyrethrins since they appear to persist under anaerobic conditions. Biodegradation under aerobic conditions occurs fair ly rapidly with half-lives of a few days. Volatilization is not expected to be an important transport process since pyrethrins tend to have relatively low vapor pressure and Henry’s Law constant.

Pyrethrins 1 and 2 have a range of water sol ubilities of 0.2-9.0 mg/L, a nd its hydrophobic nature leads to strong soil adsorption and a tendency to partition to sedime nt in aquatic systems. The reported value of log octanol/ wate r partition coefficients of 4.3-5.9 suggest that pyrethrins have a potential to bioaccumulate in aquatic organisms, assuming that chemical metabolism is negligible. However, the measured bioconcentration factor in fish (471x whole fish; de puration was rapid: by day 1, 77% of the accumulated [ 14 C]-residues were eliminated, see Table 3.10 ) is much lower than that expected based on K OW alone, which suggests that pyret hrins metabolism by fish is substantial. Pyrethrins have a high molecular weight of ≥ 324 g/mol. With a vapor pressure of
~2.0 x 10 -5 to 4.0 x 10 -7 torr, and due to its solubility limit range, its calculated Henry’s Law Constant is relatively low ( e.g. , 7.73 x 10 -7 atm-m 3 /mol for pyrethrins 1). Pyrethrin 1’s air/water partition coefficient (K AW ) is ~3.14 x 10 -5 (unitless), which classifies it as ‘slightly volatile from a water surface’ (USEPA 2008), and the C water+soil /C air = ~9.58 x 10 6 , which classifies the chemical
as ‘non-volatile from mo ist soil’ (USEPA 2008). Based on th ese properties, pyrethrin 1 would have a slight potential to vol atilize from wet surfaces, but not fr om moist soil. The slight potential to volatilize of pyrethr in 1 is attenuated by its tendenc y to bind to organic matter ( e.g. , soils, sediments, or organic matter a nd particulate in natural water). Table 3.2 lists various important physicochemical characteristics of the chemical. Table 3.10 lists available environmental fate characteristics of pyrethrin 1, along with information on the major and minor degradates detected in the submitted environmental fate and transport studies.

Table 3.2. Physicochemical Properties of Pyrethrins

Property Pyrethrin

Value MRID or Source

Density/ Specific Gravity 0.982 g/mL pyrethrin 1 1.5242 g/mL pyrethrin 2 1.5355 g/mL USEPA 2006

Boiling Point ( 0 C) 146–148 ° C at 2x10 -3 torr for pyrethrin 1

196–198 ° C at 7x10 -3 torr for pyrethrin 2

136–138 ° C at 8x10 -3 torr for cinerin 1

182–184 ° C at 0.001 torr for cinerin 2 USEPA 2006Table 3.2. Physicochemical Properties of Pyrethrins Pyrethrin Property Value MRID or Source

Vapor Pressure (25 0 C) pyrethrin 1: 2x10 -5 torr pyrethrin 2: 4x10 -7 torr cinerin 1: 1.1x10 -6 torr (a)

cinerin 2: 4.6x10 -7 torr (a) jasmolin 1: 4.8x10 -7 torr (a) jasmolin 2: 1.9x10 -7 torr (a) USEPA 2006 (a) Estimated value from
EPISuite

Water Solubility (ppm) pyrethrin 1: 0.2 ppm pyrethrin 2: 9.0 ppm USEPA 2006

Henry’s Law Constant (atm-m 3 /mole) pyrethrin 1: ~7.7x10 -7 Atm-m 3 /mol pyrethrin 2: ~2.2x10 –8 Atm-m 3 /mol
‘Non-volatile under field conditions’

cinerin 1: 9.6x10 -7 Atm-m 3 /mol
cinerin 2: 9.2x10 -10 Atm-m 3 /mol jasmolin 1: 1.3x10 -6 Atm-m 3 /mol jasmolin 2: 1.2x10 –9 Atm-m 3 /mol Calculated for pyrethrin 1 and pyrethrin 2
Estimated for all the other chemicals using EPISuite

Octanol – water partition coefficient

(log K OW ) (25 o C) pyrethrin 1: 5.9 pyrethrin 2: 4.3 USEPA 2006

Air-water partition

coefficient (K AW ) K AW = C air /C water = HLC/RT
= 3.14 x 10 -5 (unitless) for pyrethrin 1 ‘Slightly volatile from a water surface’ Temperature assumed to be
25 0 C, calculated value; USEPA, 2008 Octanol-air partition

coefficient (K OA ) K OA = K OW /K AW = 2.53 x 10 10 for pyrethrin 1 Calculated Value

C water /C air ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

×× ×××

= 6
air water 10GMW P 760RT S

C C = RT/HLC

= 1/K AW = 31,757 (unitless) for pyrethrin 1 ‘Slightly volatile from a water surface’ Calculated USEPA, 2008

Volatilisation Flux ≤ 0.002 μ g/cm 2 ·hour MRID 43096604

C water+soil /C air C water+soil /C air = (1/K AW ) (1/r + K d ) =
9.58 x 10 6

‘Non-volatile from moist soil’ Calculated Value, using the

mean K F (assumed to be the
same than K d ) USEPA, 2008

For pyrethrin 1, log K OA > 5, log K OW > 2 and therefore is preliminarily identified as having a potential to biomagnify in terrestrial food chains. 1 However, its rate of biotransformation is moderate in the environment, and it appears to be moderately rapid in fish. Specifically, the bioconcentration factor is 471x for whole fish, whic h is much lower than would be expected if biotransformation was minimal. Furthermore, it is depurated rapidly in fi sh (depuration half life <1 day). Therefore, the potential of pyrethrins to biomagnify in terrestrial food chains appears to be low because it should be similarly bi otransformed by terrestrial organisms.

Even though various degradates were observed in the laboratory studies ( e.g. chrysanthemic acid, pyrethric acid and chrysanthemum dicarboxilic acid), it was found that all of them were the result

14 1 This preliminary conclusion is based on the following presumption: If log K OA > 5, log K OW > 2 and the rate of chemical transformation is low, the chemical may biomagnify in terrestrial food chain. Gobas et al. 2003 and Armitage & Gobas, 2007 support this pr esumption, which is utilized here only as a broad referen ce to determine the potential for biomagnification.15 of the rupture of the ester bond of the parent molecu le. It is believed that the resulting molecules are not as toxic as the parent be cause they presumably have lost the neurotoxic mode of action. Figure 3.3 shows the chemical structures of pyrethrin s’ major potential degradation products. All of them are expected to be more soluble a nd mobile than their respective parent compounds, especially the acids. Based on the information fr om pyrethrin 1, chrysanthemic acid appeared to be short lived and pyrethric acid and chrysant hemum dicarboxylic acid would be expected to behave similarly. The E-isomer of pyrethrin 1 (not shown in the figure) was observed in the photolysis on soil study to be short lived as well, therefore, it is of low concern.

No registrant-submitted data are available that ex amine the ecotoxicity of pyrethrins degradates. At this time, the degradates wi ll not be considered stressors of concern in the forthcoming environmental fate and ecological risk assessmen t. These conclusions ar e in agreement with EPA’s Health Effects Division’s (HED) approach of considering only the parent as the residue of concern for purposes of tolerance expression and risk assessment (HED chapter of the Reregistration Eligibility Decision Docume nt (RED) for pyrethrins, dated April 1 st 2009; DP Barcode D357566, see Appendix I).Figure 3.3. Structures of Potential Degr adation Products of the Pyrethrins

Nomenclature of Pyrethrin Breakdown Products

Common Name Chemical Name

Chrysanthemic acid 2-(1-isobutenyl-3,3-dimethylcyclopropanecarboxylic acid or 3-isobutenyl-2,2-dimethy lcyclopopanecarboxylic acid CDA or Chrysanthemum Dicarboxylic Acid 2,2-dimethyl-1,3-cyclopropanedicarboxylic acid

3.1. Mechanism of Action

Pyrethrins and pyrethroids share similar mode s of action, resembling that of DDT, and are considered axonic poisons that a ffect both the periphera l and central nervous system. It is now
well established that severe ne urological symptoms of poisoni ng with pyrethroids and DDT in
mammals and insects are the result of modification of Na + channel activity (cellular pores through which sodium ions are permitted to enter the axon to cause excitation) (Matsumura,1985). Advanced electrophysiological experiments using voltage clamp and patch clamp, together with ligand-binding and ionic flux experiments, have unve iled unique actions of pyrethroids of keeping
the Na + channel in the open state for an extremel y long period, sometimes as long as several
seconds. This modification of Na + channel properties leads to hyperactivity of the nervous system. Pyrethroids have also been shown to suppress GABA and glutamate receptor-channel complexes and voltage-activated Ca 2+ channels, but the toxicologica l significance of these actions is uncertain. Relative to physio logical responses, researchers ha ve designated two types of pyrethroids, Type I ( e.g. , pyrethrins, S-bioallet hrin, resmethrin, permethrin) and Type II ( e.g. , cypermethrin, deltamethrin, fenvalerate). Type I pyrethroids’ action is mainly associated with compounds that cause nerve excitation symptoms typi fied by the appearance of repetitive firing of

1617 axons in the peripheral nervous system and a negatively correlated temperature reversible knockdown property (similar to DDT) (Clark an d Matsumura, 1987). Pyrethrins are nonsystemic insecticides that work by physical contac t to the insect or by i ngestion, and they have a slight repellent effect.

The paralyzing effects caused by pyrethrins usua lly cannot occur without a synergist. For example, the synergist compound in PYRENONE® Crop Spray ( e.g. , EPA Reg. No. 432-1050) is piperonyl butoxide, and it blocks the meta bolic pathway that would breakdown pyrethrin
before the toxic effect occurs. Products that c ontain pyrethrins are prim arily used as a knockdown agent on the insects and the ad dition of a synergist does contri bute to the killing efficiency of a formulation (Casida and Quistad, 1995).

3.2. Overview of Pesticide Usage

The use information presented in this problem formulation was obtained from the tables in Appendix A-1 and Appendix A-2 dated 03/22/20 10 (and further revised 05/12/2011), from the Pyrethrins BEAD’s Chemical Profile for Regi stration Review (USEPA 2011), from various evaluated labels, and from the June 2006 Rere gistration Eligibility Decision Document for Pyrethrins. There are around 640 pyrethrin-contai ning products. Use reported for pyrethrins appears to be based on a subset of the universe of labels available for the chemical, as shown in
the 05/12/2011 revision of the Appendix A-1 and Appendix A-2.

The pyrethrins have numerous uses . A summary of agricultural use patterns for pyrethrin is
shown Table 3.3 . Note that for all the uses, the maxi mum single and seasonal application rate, the maximum number of applications at th e maximum rate, and the minimum retreatment interval are the same. Of the numerous crops mentioned, rice is worth mentioning separately because it will be assessed in a different way than other agricultural uses (see crop under Crop Group 15). This crop will be assessed using the tier 1 Rice Paddy Model (or further characterized using the PFAM model, see below). In all inst ances, there is a 1 day retreatment interval for high pest pressure, compared to a 3 day retr eatment interval for normal pest pressure.

Table 3.3. Summary of Agricultural Use Information for the Pyrethrins

Maximum Applic.

Rate (all crops) Maximum Seasonal Rate (all crops) Maximum Number of Applications (all crops) Minimum Retreatment Interval (all crops)

0.050 lb a.i./A 0.50 lb a.i./A 10 1 day (extreme pest pressure) 3 days (normal pest pressure) Pre-harvest interval (PHI) 0 days for all crops, except for cotton seed, for which it is 14 days. Application to hydroponically grown crops 10 applications at 0.10 ppm in water. Surface application to greenhouse grown crop 10 a pplications at 0.0012 lb a.i./1,000 sq. ft or 0.050 lb a.i./A. Space application to greenhouse grown crop 10 a pplications at 0.00014 lb a.i./1,000 cu ft. Other restrictions: Do not harvest until spray has dried. Do not wet foliage to point of runoff or drip. Crop Group 1: Root and Tuber Vegetables [including Arracacha; Arrowroot; Artichoke, Ch inese; Artichoke, Jeru salem; Beet, garden, Beet, sugar; Burdock, edible; Canna edible; Carrot; Cassava; Cele riac; Chayote; Chervil, turnip-r ooted; Chicory; Chufa; Dandeli on; Dasheen; Ginger; Ginseng; Horseradish; Leren; Parsley, turnip-ro oted; Parsnip; Potato; Radish; Radish, Oriental; Rutabaga; Sals ify; Salsify, black; Salsify, Spanish; Skirret; Sweet Potato; Tanier; Taro; Turmeric; Turnip; Yam bean; and Yam, true] Crop Group 2: Leaves of Root and Tuber Vegetables [including Beet, garden; Beet, sugar; Bu rdock, edible; Carrot; Cassava; Chervil, turnip-rooted; Chicory; Dasheen; Parsnip; Radish; Radish, Oriental; Rutabaga; Salsify, black; Tanier; Taro; Turnip; and Yam, tr ue] Crop Group 3: Bulb Vegetables [including Garlic; Garlic, great headed; Leek; Onion, dry bulb; Onion, green; Onion, potato; Onion, tree; Onion, welsh; and Shallot]Table 3.3. Summary of Agricultural Use Information for the Pyrethrins
Crop Group 4: Leafy Vegetables (Except Brassica Vegetables) [including Amaranth, leafy; Ar ugula; Cardoon; Celery; Celery, Chinese; Celtuce; Chervil; Chrysanthemum, edible-leaved; Chrysanthemum, garland; Corn salad; Cre ss, garden; Cress, upland; Dandelion; Dock; Endive; Fennel, Florence; Kale, sea; Lettuce, h ead; Lettuce, leaf; Orach; Parsley; Purslane, garden; Purslane, winter; Radicchio; Rhubarb; Spinach; Spinach, Chinese; Spinach, New Zealand; Spinach, vine; Swiss chard; and Tampala] Crop Group 5: Brassica (Cole) Leafy Vegetables [including Broccoli; Broccoli, Chinese; Broccoli raab; Brussels sprouts; Cabbage; Cabbage, Chinese, Bok choy; Cabbage, Chinese, mustard; Cabbage, Chinese, napa; Cauliflower; Collards; Kale; Kohlrabi; Mustard greens; Mustard spinach; and Rape greens] Crop Group 6: Legume Vege tables (Succulent or Dried) [including Bean (adzuki, broad, dry, kidney, lablab, lima, moth, mung, navy, pink, pinto, rice, runner, snap, tepary, ur d, wax, yardlong); Catjang; Chickpea; Cowpea; Guar; Gum, edible; Jackbean; Lentil; L upin, grain; Pea (blackeyed, crowder, dry, dwarf, edible-pod, English, field, garden, green, pigeon, snow, southern, succulent, sugar snap); Soybean; and Swordbean] Crop Group 7: Foliage of Legume Vegetables [including Bean (dry, lima, snap); cowp ea; Lupin, grain; Pe a (field and pigeon); Soybean] Crop Group 8: Fruiting Vegetables (Except Cucurbits) [including Chili; Eggplant; Groundche rry; Pepino; Pepper (bell, nonbell, nonbell sweet); Tomatillo; Tomato] Crop Group 9: Cucurbit Vegetables [including Balsam apple; Balsam pear; Cantaloupe; Chayote; Cucumber; Cucumber, Chinese; Gherkin, West Indian; Gourd, edible; Me lon; Melon, citron; Muskme lon; Pumpkin; Squash; Squa sh, summer; Squash, winter; Watermelon; Waxgourd, Chinese] Crop Group 10: Citrus Fruits (Citrus spp., Fortunella spp.) [including Calamondin; Ci tron, citrus; Citrus; Citr us hybrids; Grapefruit; Kumquat; Lemon; Lime; Mandarin, sa tsuma; Orange, sour; Orange, sweet; Pummelo; Tangelo; Tangerine] Crop Group 11: Pome Fruits [including Apple; Crabapple; Loquat; Mayhaw; Pear; Oriental Pear; and Quince] Crop Group 12: Stone Fruits [including Apricot; Cherry, sweet; Cherry, tart; Nect arine; Peach; Plum; Plum, chickasaw; Plum, damson; Plum, Japanese; and Plum, prune] Crop Group 13: Berries [including Blackberry, Blueberry; Currant; Elderberry; Gooseberry; Huckleberry; Loganberry; and Raspberry (black and red)] Crop Group 14: Tree Nuts [including Almond; Beech nut; Brazil nut; Butternut; Cashew; Chestnut; Chinquap in; Filbert; Hickory nut; Macadamia nut; Pecan; Pistachio; Walnut, black; and Walnut, English] Crop Group 15: Cereal Grains [including Barley; Buckwheat; Corn (field, pod, pop, and swee t); Millet; Millet, p earl; Millet, proso; Oat; Rice; Rice, wild ; Rye; Sorghum, grain; Teosin te; Triticale; Wheat; Wheat, vavilovi; Wheat, wild einkorn; and Wheat, wild emmer] Crop Group 16: Forage, Fodder, and Straw of Cereal Grains [including Barley; Corn (field, p od, pop, and sweet); Millet; Millet, pearl; Millet, proso; Oat; Rice; Rice, w ild; Rye; Sorghum (forage and grain); Teosin te; Triticale; Wheat; Wheat, vavilovi; Whea t, wild einkorn; and Wheat, wild emmer] Crop Group 17: Grass Forage, Fodder, and Hay [including Alkali s acaton; Alkaligrass; Arizona cott ontop; Bahiagrass; Beachgrass; Bentgrass; Bentgrass, spike; Be rmudagrass; Blowoutgrass; Bluegra ss; Bluegrass, silky; Bluestem australian; Bluestem, big; Blues tem, Caucasian; Bluestem, Diaz; Bluestem, little; Bluestem, sand; Bluestem, silver; Bluestem, south African; Bluestem, yellow; Brist legrass, plains; Bromegrass; Broomsedge; Bu ffalograss; Buffelgrass; Canary grass, annual; Canary grass, reed; Caribgrass; Carpetgrass; Carpetgrass, broadleaf; Centipedegrass; Cordgrass, marsh hay; Crabgrass; Curly mesquite; Dallisgrass; Dropseed, pine; Dropseed, sand; Dropseed, tall; Fescue; Fingergrass, feather; Foxtail, creeping; Foxtail, meadow; Gamagrass, eastern; Grass; Grass, galleta; Gr ass, gama; Grass, muhly; Grass, pasture; Grass, St. Augustine; Grass, wild rye; Grass, zoysia; Hairgrass tu fted; Hardinggrass; Indiangrass; Junegrass; Limpograss; Lovegrass; Maidencane; Mannagrass; Millet, foxtail; Millet, Japanese; Molassesgrass; Napiergrass; Needlegrass; Oat, sand; Oat, slender; Oat, wild; Oatg rass; Oatgrass, tall; Oniongrass; Orchardgrass; Pangolagrass; Pani cgrass; Paspalum; Polargrass; Qu ackgrass; Redtop; Reedgrass; Rhodesgrass; Rhodesgrass, multiflower false; Ricegrass, indian ; Ryegrass, Italian; Ryegrass, perennial; Sand reed, prairie; Sixweeks threeawn; Sloughgrass; Smilograss; Sorghum, forage; Spikeoat; Spra ngletop, green; Squirreltail; Sudangrass; Sunolgrass; Tanglehead; Timothy; Timothy, alpine; Trisetum, spike; Vaseygrass; Veldtg rass, perennial; Velvet grass; Wheatgrass; Wheatgrass, bluebunch; Wheatgrass, crested; Wheatgrass, fairway; Wheatgrass, intermediate; Wheatgrass, pubescent; Wheatgrass, Siberian; Wheatgrass, slender; Wheatgrass, streambank; Wheatgrass, tall; Wheatgrass, thickspike; Wheatgrass, western; and Windmillgrass, hooded] Crop Group 18: Nongrass Animal Feeds (Forage, Hay, Straw, and Hay) [including Alfalfa; Arrowl eaf balsamroot; Burclover; Clover; Clover, alsike; Clover, alyce; Clover, arrowleaf; Clover, ball; Clover, berseem; Clover, bigflower; Clover, crimson; Cl over, hop; Clover, lappa; Clover, persian; Cl over, red; Clover, rose; Clover, seaside; Clover , strawberry; Clover, striate; Clover, sub; C lover, sweet; Clover, true; Clover, white; Clover, whitetip; Crownvetch; Kudzu (note: kudzu is a generally cons idered a noxious weed and not a crop in the United States); Lespedeza; Lupine; Lupine, forage; Lupine, sweet; Mustard; Sainfoin; Trefoil; Velvetbean; Vetch; and Vetch, milk] Crop Group 19: Herbs and Spices [Including Allspice; Angelica; Anise; Anise hy ssop (mint); Anise, star; Annatto; Balm; Basil; Borage; Burnet; Camomile; Caper; Caraway; Caraway, black; Cardamom ; Cardamon amomum; Cassia; Catnip; Celery, seed; Chervil; Chive; Chive, Chinese; Cinnamon; Clary; Clove; Coriander; Costma ry; Cilantro (False coriander); Cumin; Curry; Dill; Dillweed; F ennel; Fennel, florence; Fenugreek; Grains of pa radise; Horehound; Juniper berry; Lavender; Lemongrass; Lovage; Mace; Marigold, pot; Marjoram (Oregano); Mustard; Nasturtium; Nu tmeg; Parsley; Pennyroyal; Pepper, black; Pepper, white; Poppy; Rosemary; Rue; Saffr on; Sage; Savory, summer; Savory, winter; Sweet bay; Tansy; Tarragon; Thyme; Vanilla; Wintergreen; Woodruff; and Wormwood]

18Table 3.3. Summary of Agricultural Use Information for the Pyrethrins
Miscellaneous Fruit, Subtropical/Tropical [including Acerola; Atemoy a, Avocado; Banana; Carob bean; Cherimoya; Date; Durian; Feijoa; Fig; Guava; Kiwifruit; Lychee; Mango; Papaya; Passionfruit; Persimmon; Pineapple; Pomegranate; Rambutan; and Starfruit (Carambola) ] Vegetable, Oriental [including Artichoke, Chinese; Balsam pear (bitter melon); Bean, mung; Bean, yardlong; Broccoli, Chinese; Cabbage, Chinese, bok choy; Cabbage, Chinese, mustard; Cabbage, Chinese, napa; Coriander (Cilantr o); Dasheen; Ginger; Ginseng; Melon, citron; Radish, oriental; Spinach , Chinese; and Waxgourd, Chinese] (Note: Individual crops listed above bel ong to various crop groups previously listed. )
Miscellaneous Commodities: Asparagus; Coffee; Cotton; Cranberry; Grape; Jo joba; Okra; Safflower; Strawberry; Sugarcane; Sunflower; and Tea All data were based Appendices A-1 and A-2, updated 05/12/2011.

For agricultural products, appli cation methods include aerial, air blast, or ground spray (foliar). As per requirements from the Reregistration Eligibility Decision (USEPA 2006), the following label requirements should be incorporated, to av oid spray drift. However, inspection of a representative label (EVERGREEN® Crop Prot ection EC 60-6; McLaughlin Gormley King Company or MGK®, containing 6.00% pyret hrins and 60.00% PBO, EPA Reg. No. 1021-1770),
indicated that the label does not have the below mentioned requirements. The Pesticide Reevaluation Division (PRD) has confirmed that at the present time, these changes are being made for all pyrethrins labels.

SPRAY DRIFT MANAGEMENT for AGRICULTURAL CROPS

• Avoiding spray drift at the appl ication site is the responsibi lity of the applicator and the grower. The interactions of many equipmen t and weather-related factors determine the potential for spray drift. The applicator and the grower are responsib le for considering all these factors when making decisions.

• Do not apply at wind speeds greater th an 10 mph at the application site.

• Do not make any type of applicat ion into temperature inversions.

• Apply as a medium or coarse r spray (ASABE standard 572).

• Additional requirements for aerial applications : a) Do not release spray at a height greater than 10 feet above the ground or crop canopy. b) The boom length must not exceed 75% of the wingspan or 90% of the ro tor blade diameter. c) Aerial applicators must consider flight speed a nd nozzle orientation in determining droplet size. d) When applications are made with a cross-wind, the swath will be displaced downwind. The applicator must compensate for this di splacement at the downwind edge of the application area by adju sting the path of the aircraft upwind.

• Additional requirements for ground applications: Do not release spray at a height greater than 4 feet above the ground or crop canopy.

• Additional requirements for airblast applica tions: a) Direct sprays into the canopy. b) Turn off outward pointing nozzles at ro w ends and when spraying outer rows.

The pyrethrins are toxic to fis h, aquatic invertebrates and bene ficial insects. The following
Environmental Hazards statements are required for products labele d for outdoor uses other than mosquito adulticide (USEPA 2006):

19ENVIRONMENTAL HAZARD STATEMENTS

• This product is toxic to aquatic organisms, including fish and invertebrates. Drift and runoff may be hazardous to aquatic organisms in water adjacent to treated areas. This product may contaminate water through runoff. This product has a potential for runoff for several weeks after application. Poorly draini ng soils and soils with shallow water tables are more prone to produce runoff that contains this product.

• This product is highly toxic to bees exposed to direct treatment on blooming crops or weeds. Do not apply this pr oduct or allow it to drift to blooming crops or weeds while bees are actively visiting the treatment area.

• Do not apply directly to water, to areas wh ere surface water is present or to intertidal areas below the mean high water mark. Do not contaminate water when disposing of equipment wash-waters or rinsate.

The pyrethrins also have multiple non-agricultural uses, as described in Table 3.4 . They include among others, garden crops and ornamentals, and lawn.

Table 3.4. Summary of Non-Agricultural Crops for the Pyrethrins

Use Single App. Rate Number of Apps. Seasonal App. Rate (lb a.i./A) Interval Between Apps. (days)
Preharvest Application to Garden Crops Residential app lications to garden crops. 0.050 lb a.i./A 10 0.50 lb a.i./A 1 (extreme pressure), 3 (normal pressure) Residential application to hydroponically grown

crops 0.10 ppm in water 10 NS

Non-food Crops in Greenhouse: Orna mental, Flowering and Foliage Plants Surface applications 0.15 lb ai/A NS NS 1 Space spray 0.00042 lb/ 1,000 cu ft NS NS 1 Non-food Crops Grown Outside: Ornamentals, Flowering and Foliage Plants, and Lawn

Surface applications (including fire ants and turf diagnostic aid) Residential: 0.10 lb ai/A)
Non-residential 0.0075 lb/ 1,000 sq ft NS NS 1

Crack/crevice or spot surface applications (including fire ants and turf diagnostic aid) 0.002 lb ai/1,000 sq ft NS NS 1

Crack/crevice or spot surface applications (including fire ants and turf diagnostic aid) .002 lb ai/ 1,000 sq ft NS NS 1

NS = Not specified

Furthermore, the pyrethrins have mosquito contro l uses. Applications are usually using very small droplet sizes ( i.e. , Ultra-Low Volume or ULV). For th ese uses, the master label says two application rates, both of whic h are much smaller than for typi cal agricultural applications ( Table 3.5 ).

Table 3.5. Adulticide Uses for the Pyrethrins

Use Max. App. Rate/ units Max. App. Rate per Year
Agricultural Crops/Soils: Groups of Agricultural Crops Whic h Cross Established Crop Groupings (Croplands); Agricultural Uncultivated Areas: Fallow lands, Pastures, and Rangelands; Intermittently Flooded Areas/Water; Irrigation Systems
Thermal fog 0.0025 lb ai/A Do not apply more than 0.2 lbs ai/acre/year in any treated

20Table 3.5. Adulticide Uses for the Pyrethrins

Use Max. App. Rate/ units Max. App. Rate per Year Non-thermal fog
ULV 0.008 lb ai/A area.

Various restrictions for the adulticide uses required during the RED process (USEPA 2006) are
as follows:

SPRAY DRIFT MANAGEMENT for WI DE AREA MOSQUITO ABATEMENT

A variety of factors incl uding weather conditions ( e.g. , wind direction, wind speed, temperature, relative humidity) and me thod of application ( e.g. , ground, aerial, airblast, chemigation) can influence pesticide drift. The applicator must evaluate all factors and make appropriate adjustments when applying this product.

WIND SPEED:

Apply only when wind speed is greater than or equal to 1 mph.

Ground-based wide area mosquito abatement application:

• Spray equipment must be adjusted so that th e volume median diameter is less than 30 microns (D v0.5 < 30 μ m) and that 90% of the spray is co ntained in droplets smaller than 50 microns (D v0.9 < 50 μ m). Directions from the equi pment manufacturer or vendor, pesticide registrant or a test facility using a laxer-based measurement instrument must be used to adjust equipment to produce accepta ble droplet size spectra. Application equipment must be tested at least annually to confirm that pressu re at the nozzle and nozzle flow rate(s) ar e properly calibrated.

Aerial wide area mosquito abatement application:

• Spray equipment must be adjusted so that the volume median diameter produced is less than 60 microns (D v0.5 < 60 μ m) and that 90% of the spra y is contained in droplets smaller than 80 microns (D v0.9 < 80 μ m). The effects of flight speed, and for non-rotary nozzles, nozzle angle on the droplet size spectr um must be considered. Directions from the equipment manufacturer or vendor, pesticide registrant or a test facility using a wind
tunnel and laser-based measurement instrument must be used to adjust equipment to produce acceptable droplet size spectra. Applic ation equipment must be tested at least annually to confirm that pre ssure at the nozzle and nozzl e flow rate(s) are properly
calibrated.

RELEASE HEIGHT:

Fixed wing:

• Apply using a nozzle height of no less than 100 feet above the ground or canopy.

Rotary wing:

• Apply using a nozzle height of no less than 75 feet above the ground or canopy.

21The agricultural usage of pyrethrin, from the Screen ing Level Usage Analysis (SLUA) is provided in Table 3.6 . The table is arranged by crop in al phabetical order. According to the table, the major agricultural us e for pyrethrin is wheat, with 2000 lb a.i. Numerous crops are provided in the table, for which the pounds of ac tive ingredient applied is <500. The crop with the highest percent crop treated is spinach (ave rage 5%, maximum 20%). Various other crops have moderate percent crop treated (i.e., 5-15%); however, for most of the crops, the percent crop treated is small (i .e., <1 or <2.5%).

Table 3.6. Screening-Level Estimates of Agricultural Uses of Pyrethrin (SLUA) 2

Crop Lb. A.I. Percent Crop Treated

Avg. Max.

Alfalfa <500 <1 <2.5

Almonds <500 <1 <2.5

Apples <500 <1 <2.5

Artichokes <500 5 15

Beans, Green <500 <1 <2.5

Broccoli <500 <2.5 5

Brussels Sprouts* <500 NC NC

Cabbage <500 <1 <2.5

Caneberries <500 5 10

Cantaloupes <500 <1 <2.5

Carrots <500 5 5

Cauliflower <500 5 10

Celery <500 <2.5 5

Cherries <500 <1 <2.5

Chicory* <500 NC NC

Corn <500 <1 <2.5

Cotton <500 <1 <2.5

Cucumbers <500 <1 <2.5

Dry Beans/Peas <500 <1 <2.5

Figs* <500 NC NC

Grapes <500 <1 <2.5

Hazelnuts (Filberts) <500 <1 <2.5

Lemons <500 5 5

Lettuce <500 5 10

Nectarines* <500 NC NC

Olives* <500 NC NC

Onions <500 <1 <2.5

Oranges <500 <1 <2.5

2 Dated 01/21/2011

22Table 3.6. Screening-Level Estimates of Agricultural Uses of Pyrethrin (SLUA) 2

Percent Crop Treated

Crop Lb. A.I. Avg. Max.

Peaches <500 <1 <2.5

Pears <500 <1 <2.5

Peas, Green <500 <1 <2.5

Pecans <500 <1 <2.5

Peppers <500 <2.5 5

Pistachios <500 <1 <2.5

Pomegranates* <500 NC NC

Potatoes <500 <1 <2.5

Prunes <500 <1 <2.5

Pumpkins <500 <1 <2.5

Sorghum <500 <1 <2.5

Soybeans <500 <1 <2.5

Spinach <500 5 20

Squash <500 <2.5 5

Strawberries <500 5 15

Sugarcane <500 <1 <2.5

Sunflowers <500 <1 <2.5

Sweet Corn <500 <1 <2.5

Tomatoes <500 <1 <2.5

Walnuts <500 <1 <2.5

Watermelons <500 <1 <2.5

Wheat 2,000 <1 <2.5

Sorted alphabetically. All numbers rounded. <500 Less than 500 pounds of active ingredient <2.5 Less than 2.5 percent of crop treated <1 Less than 1 percent of crop treated N/C Only Lbs. A.I. available * CA data only (95% or more of U.S. acres in California)
SLUA data sources include: USDA-NASS (United States Depart ment of Agriculture's National Agricultural Statistics Service) (pesticide usage data from 2001 to 2008) Private Pesticide Market Research (p esticide usage data from 2001 to 2008) California DPR (Department of Pe sticide Regulation) (data for 2000 to 2008) These results reflect amalgamated data developed by the Agency and are releasable to the public.

BEAD provided agricultural information by states in its Pyrethrins Chemical Profile for Registration Review (USEPA 2011): “On average, the states with the most agricultural usage in terms of pounds a.i. applied are California (52%), Oklahoma (16%), and Arizona (6%).”

23Table 3.7 provides a summary of several nonagricultur al (terrestrial/ outd oor) or non-crop uses for pyrethrin. The uses are classified by br oad categories as follows: commercial animal housing, outdoor agricultural premises, reside ntial sites – outdoors, and outdoor eating establishments. For various uses, the maximum app lication rate is expresse d in units other than “lb a.i./A” and in some instances it is expressed in units of percent pyreth rins. Many of the uses may well involve substantiv e exposure to wildlife, especially a quatic organisms, and they will be assessed accordingly ( e.g. , surface applications).

Table 3.7. Non-Crop Outdoor Uses for Pyrethrins

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App.
Interval/

days Commercial Animal Housing Animal areas and quarters; Animal shelte rs; Catteries; Dog runs; Kenne ls; Pet grooming shops; Pet stores; Research animal quarters; Zoos. (Animals are not present during application)

Surface – General 0.056 lb ai/1,000 ft 2 NS NS 1

Surface - Crack and crevice or spot 0.056 lb ai/1,000 ft 2 NS NS 1

Space – General 0.0033 lb ai/1,000 ft 3 NS NS 1 (restricted

to commercial pet areas)

Space - Metered release 0.000476 lb a.i./1000 ft 3 / day NS NS NS

Outdoor Agricultural Premises Empty Uncultivated Agricultural Areas: Corrals; Dairy areas; Farms; Goat holding areas; Hog operations; Rights-of-way; Sheep holding areas. Empty Cattle Feedlots: Beef cattle operations; Feedlo ts; Holding lots; Livestock lots; Swine lots and yards

Surface - General 0.0075 lb a.i./1,000 ft 2 NS NS 1

Surface - Crack and crevice or spot 0.22 lb ai/1,000 ft 2 NS NS 1

Impregnated mat 1.0% pyrethrins NS NS 1

Combustible coils 1.0 % pyrethrins NS NS 1

Residential Sites – Outdoor
Ant hills; Ant nests; Ant trails; Backyards; Doors; Driveways; En tranceways; Mud dauber, wasp, and yellow jacket nests; Outside surfaces of buildings; Patio furniture; Picnic areas; Residential areas; Screens; Siding; Spigots; Storage areas; Tree holes; U nder eaves; Under siding; Wall voids; Windows.
Nonagricultural Outdoor Buildings/Structures: Atriums; Carports ; Decks; Fences; Gazebos; Lanais ; Porches; Sheds; Tree houses; Tunnels and cavities in wood; Verandas; Tents. Fencerows; Hedgerows; Nonagricultural Rights-of-way; Paths; Patios; Paved Areas: Private Roads; Sidewalks; Garbage bins; Dumpsters; Meter boxes; Electri cal equipment; Electr ical fittings; Manure; Compost piles.

Surface – General 0.002 lb a.i./1,000 ft 2 NS NS

1 Surface - Crack and crevice or spot 0.056 lb a.i./1,000 ft 2 NS NS

Impregnated mat 1.0% pyrethrins NS NS

Combustible coil 1.0% pyrethrins NS NS Outdoor Eating Establishments Eating Establishments Equipm ent/Utensils, Food Handling Areas, Food Servi ng Areas, Non-Food Areas of outdoor eating
establishments and drive-in restaurants
Surface applications 0.0075 lbs a.i./1000 ft 2 NS NS

1 Crack/crevice or spot surface 0.056 lbs a.i./1000 ft 2 NS NS

Impregnated mat 1.0% pyrethrins NS NS

Combustible coil 1.0% pyrethrins NS NS

Other uses are classified as indoor. They include several broad categories as follows:

24postharvest applications to ve getables, fruit and nuts, bulk gr ain and seed, application to agricultural premises and equipment – indoor, residential – indoor, co mmercial/ industrial/ institutional establishments – indoor, eati ng establishments – i ndoor, food handling and processing establishments – indoor, retail and storage – indoor, transportation – indoor, and pet premise treatment.

Table 3.8. Indoor Uses for Pyrethrins

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App.
Interval/

days Postharvest Application to Vegetables, Fruit, and Nuts
Food/Feed Storage Areas -Full: Postharves t Application to Apple, Blackberry, Blueberry, Boysenberry, Cherry, Crabapple, Currant, Dewberry, Fig, Gooseberry, Grape, Guava, Loganberry, Mango, Muskmelon, Orange, Peach, Pear, Pea, Pin eapple, Plum, Potato, Raspberry, or Tomato in baskets, on trucks, in processi ng plants, in hampers, or in temporary storage areas (including raw stock stacked in yards) Copra (processed) in baskets, on trucks, in processing plants, in hampers, or in tem porary storage areas (including raw stock s tacked in the yard) Postharvest application to Almonds, Peanut s, and Walnuts (English/black) in bulk.

Surface - General 0.01 lb a.i./ 1,000 ft 2

10 0.10 lb a.i./
1000 ft 2

7 Surface - Direct application to fruits or tomatoes in baskets or hampers 0.16 ppm NS

Dip or spray 0.0004 lbs a.i./ gallon NS

Space - Fruits, vegetables, and copra 0.001 lb a.i./ 1,000 ft 3 0.010 lb a.i./
1000 ft 3
Postharvest Direct Applicat ion to Bulk Grain and Seed

Bulk Grain and Seed 0.10 lb a.i./ 1,000 bushels grain NS NS 30

- Barley 0.0033 oz/cwt NS NS 30

- Beans 0.0027 oz/cwt NS NS 30

- Beans, lima 0.0029 oz/cwt NS NS 30

- Birdseed 0.0032 oz/cwt NS NS 30

- Buckwheat 0.0033 oz/cwt NS NS 30

- Cocoa beans 0.0037 oz/cwt NS NS 30

- Corn 0.0029 oz/cwt NS NS 30

- Cottonseed 0.0057 oz/cwt NS NS 30

- Flax 0.0029 oz/cwt NS NS 30

- Grain sorghum 0.0029 oz/cwt NS NS 30

- Oats 0.0050 oz/cwt NS NS 30

- Pea (field) 0.0027 oz/cwt NS NS 30

- Rice 0.0036 oz/cwt NS NS 30

- Rye 0.0029 oz/cwt NS NS 30

- Wheat: club, comm on, durham 0.0027 oz/cwt NS NS 30

- Wheat: emmer, spelt 0.0040 oz/cwt NS NS 30

25Table 3.8. Indoor Uses for Pyrethrins

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Min. App. Rate per Interval/

Year days Application to Agricultural Premises and Equipment – Indoor
Greenhouses (empty) Agricultural/Farm Structures/Buildings and Equipment: Animal houses; Calf hutches; Ca lving pens and parlors; Dairies; Dairy farms; Goat houses; Livestock housing structures; Loafing sheds; Poultry houses; Poultry operations; Rabbit houses; Rabbit hutches; Stables; Swine houses. Barns/Barnyards/Auction Barns: Barns (Beef, Cattle, Dairy, Horse, Hog, and Livestock) Dairy Farm Milking Stalls/Parlors : Milk houses; Milking parlors Dairy Farm Milk Storage Room s/Houses/Sheds: Milk rooms Dairy Farm Milk Handling Facilities/Equipment: Milk handling equipment Dairy Farm Milking Equipment: Milking equipment Seed Houses/Stores/Storage Areas/ Warehouses: Stored seed warehous es; Seed warehouse bins; Granarie s; Seed storag e sites; Seed bins; Stable bins; St ored seed warehouses
Silos and Mushroom houses

Surface – General 0.056 lb ai/1,000 ft 2 NS NS

1 Space – General 0.0008 lb ai/1,000 ft 3 NS NS

Space - Metered release 0.000476 lbs a.i./
1000 ft 3 / day NS NS

Residential – Indoor Household/Domestic Dwellings: Apartments ; Cabins; Campers; Condominiums; Dwelli ngs; Homes; Mobile homes; Recreational vehicles; Residences; Public housing; Sheds; Toolsheds; Townhouses. Household/Domestic Dwelling Contents: Beds (cracks, crevices, framework); Bedding; Bookcases; Box springs; Boxes; Cabinets; Carpet; Cooking equipment; Cut Flowers; Drawers; Dressers; Draperies; Dryers; Equi pment; Fabrics; Flowering plants; Foliage plants; Formica; Furniture; Furniture bases; Furniture legs; Glass; Light fixtures; Linoleum; Machinery; Mattresses; Picture fr ames; Plastic fabric bags; Refrigerator; Rugs; Shelves; Shrubs; Sofas and Chairs; Sofa and Chair surfaces; Soffits; Stainless steel; Storage drawers; Stored items; Stoves; Tables ; Tiles; Trees; Upholstered furniture ; Upholstery; Vinyl tile; Washers. Household/Domestic Dwellings Indoor Food Ha ndling Areas (food covered): Cupboards; Kitchens; Sinks; Underneath sinks; Food

areas. Household/Domestic Dwellings Indoor Nonfood Handling Areas: Attics; Basements; Bedr ooms; Closets; Closed porches; Crawl spaces; Dining rooms; Garages; Pantries; Porches; Solariums; Storage areas; Sun porches; Utility rooms; Bathrooms. Household Domestic Dwellings Indoor Premises: Baseboards; Closed void areas; Cr acks and crevices; Dark corners; Doorframes; Door jambs; Doors; Door sills; Drains; Equipment voids; False ceilings; Floors; F oundations; Moldings; Mo ist places; Niches; Pipes; Screens; Soffits; Tunnel s and cavities in wood; Walls; Windows; Window frames; Window sills; Weep holes; Woodwork; Voids in attics, walls, ceilings, and equipment. Electrical Supplies/Equipment: Meter boxes; Electrical equi pment; Electrical fittings. Human Clothing (Insect and Mold/Mildew Control): Clothing; Clothing (outerwear); Clothing (in storage); Woolens. Garbage cans and Garbage/trash compactors.

Commercial/Industrial/Institutional Establishments – Indoor
Apartments; Auditoriums; Buildings; Churches; Commercial bu ildings; Correctional facilities; Communications centers; Courthouses; Day care centers; Dorm itories; Drugstores; Elevators; Equipment voids ; Factories; Fake ce ilings; Florists; Food service storage and preparation areas; Gas stations; Hotels; Industrial buildings; Industrial installations; Institutions; Inte riorscapes; Jails; Kitchens; Laboratorie s; Laundry areas; Lavatories; Libraries; Locker rooms; Lathhouses; Missions ; Motels; Movie Theatres ; Museums; Non-food areas of commercial build ings; Non-residential buildi ngs; Offices and office bui ldings; Other commercial, industrial, and governmental sites; Parking garages; Prisons; Public buildings ; Resorts; Schools; Shadehouses; Sheds; Stores; Textile mills & warehouses; Theaters; Universities; Utilities/util ity rooms; Health care facilities; Hospices; Hospitals; Nursi ng homes; Veterinary clinics.

Eating Establishments –Indoor
Eating Establishments (Food Contac t) [Equipment/Utensils; Food Handling Areas; F ood Serving Areas]: Cafeterias; Restaurants;
Mess halls

26Table 3.8. Indoor Uses for Pyrethrins

Use Max. App. Rate/ units Max. No. Applications/
Year Max. App. Min. App. Rate per Interval/

Year days
Food Handling and Processing Establishments – Indoor
Food Handling and Processing Plant Premis es and Equipment (Food Contact): Bakeri es; Bottling plants; Beverage plants; Canneries; Conveying Equipment; Dried fruit processing plants; Feed areas of commerc ial buildings; Food areas of commercial buildings; Food processing plants; Fruit packing sheds; Mushroom processing plants; Peanut processing plants; Processing areas of dried food products; Tobacco processing plants; Wineries Meat Processing Plant Premises and Eq uipment (Food Contact): Conveying equipm ent; Edible product areas of official establishments operat ing under the meat; poultry; shell egg grading and egg products insp ection operations; Meat packing plants ; Poultry processing plants; Rabbit processing pl ants; USDA inspected meat and poultry plants Dairies/Cheese Processing Plant Premises and Equipment (Food Contact): Dairies Egg Processing Plants Tobacco Processing Plants Feed Mills/Feed Processing Plants: Conveying equipment; Feed processing and handling sites; Flour mills; Grain mills; Mills; Milling operations; Roll housing and hoppers; Stored grain mills; Rice mills Feed/Food Treatment - Storage/Processi ng/Handling Equipment: Conveying equipment; Grain handling equipment

Retail and Storage – Indoor
Commercial Storage/Warehouses Premises: Br andy storage warehouses; Dried fruit ware houses; Elevators; Food storage areas; Freight containers; Peanut storage warehouses ; Spirit storage; Storage areas; Storage areas of dried food products; Stored seed warehouses; Warehouses; Wine storag e warehouses; Tobacco warehouses Food Stores/Markets/Supermar kets Premises and Equi pment: Food marketing - storage- di stribution; Grocery and convenience stores; Stores; Supermarkets; Conveying equipment; Freight co ntainers; Stored product areas Food/Feed Storage Areas-Full: Stored product areas.

Transportation – Indoor Commercial Transportation Facilities: Airplanes; Boats; Box cars; Buses; Cabins and holds of aircraft; Commercial transportati on centers; Freight containers; Ocean fright containers; Pallets; Passenger rail cars; Railroad cars; Recreational vehicles; Ships & ships’ holds; Trains; Trucks; Trailers; Truck trailers ; Livestock hauling equipment; Horse trailers. Commercial Transportation Facilities – Empty: Grain transportati on containers (truck beds; planes; box cars; cargo ship holds);
Pallets. Commercial Shipping Containers- Empty: Grai n transportation containers (truck beds; planes; box cars; cargo ship holds); Palle ts. Trunks of Automobiles, Taxis, Limousines.

Pet Premise Treatment Pet Living/Sleeping Quarters: Areas of floors & floor coverings wher e pets may be present; areas where female insects may crawl to lay eggs, and similar hiding pla ces; Dog houses and other sleepi ng quarters; Dog runs; Pet beddin g and premises; Pet premises; Pet resting areas; Kennels.

The pyrethrins also have numerous uses on pets and other animals, as indicated in Table 3.9

. Uses include cattle (beef/range/f eeder and dairy), dair y goats (meat, dairy), dogs/ canines, cats, hogs/ pig/ swine treatments, horses, livesto ck, poultry, and sheep animal treatment, etc. Treatments include direct application to livesto ck and poultry (dust), di rect application to livestock (liquid solution, towelette, spot-on and pour-on), and direct application to poultry (liquid solution). For cattle, the retreatment interv al is 1 day while for pets, it is not specified. Applied amounts may vary depending on the formulation. Figure 3.3 shows the cattle and calves inventory as of 2007. Each dot represen ts 10,000 cattle and calves. Since exposure to water bodies due to treatment of cattle and various other animals is possible, these uses will be assessed in the ecological risk assessment to estimate potential pyrethrins exposure following application to livestock.

27Figure 3.4 Cattle and Calves Inventory as of 2007 3

Table 3.9. Pet Care, Cattle and Various Other Animal Treatments of Pyrethrins

Use Max. App.
Rate/ units Max. No. Applications/
Year Max. App. Rate per

Year Min. App.
Interval/

days Birds: Amazon parrots; Budgies; Canaries; Cockatiels; Finc hes; Love birds; Macaws; Os trich; Parakeets; Parrots. Cats (including kittens), Dogs (includi ng puppies), Monkeys, Ferrets, Rabbits. Chimpanzees; Chinchillas; Horses; Llamas; Lemurs; Minks; Ponies; Pot bellied pigs. Rodents: Gerbils; Guinea pigs; Hamsters; Mice; Rats.
Shampoos 0.3% a.i.

NS NS NS Sprays 0.20 % ai

Spot-on or Pour-on 1.0% a.i.

Dust 1.0% a.i.

Towelettes 0.2% a.i.

3 Information obtained from the follo wing website accessed 05/18/2011: http://www.agcensus.usda.gov/Publications/2007/Online_ Highlights/Ag_Atlas_Maps/Livestock_and_Animals/Live stock,_Poultry_and_Other_Animals/07-M134.asp

28Table 3.9. Pet Care, Cattle and Various Other Animal Treatments of Pyrethrins

Use Max. App.
Rate/ units Max. No. Applications/
Year Max. App. Min. App. Rate per Interval/

Year days Direct Application to Animals Cattle (Beef/Range/Feeder and Dairy); Hogs /Pig/Swine; Goats (Meat and Dairy); Kids; Sheep; Lamb; Rabbits; Game Animals (including Beefalo, Buffalo, Deer, Exotics such as European red deer, Llamas, Moose, Elk); Livestock (including Donkeys, Horses

, Ponies, Mules); and Poultry
Direct application to livestock and poultry - Dust 1.0%

NS NS 1 Direct application to livestock – Liquid Solution 0.035 lb ai/gal
Direct application to livestock - Towelette 0.2%
Direct application to livestock - Spot-on or Pour-on 1.0%
Direct application to pou ltry – Liquid Solution 0.01%

The Agency has limited use and usage information relevant to urban exposures and residential uses of pyrethrins. The Agency intends to us e available non-agricultural use and usage data, such as the Kline database, the California Department of Pesticid e Regulation’s (CDPR) Pesticide Use Reporting Data and Pest Control Operator’s usage survey, and the Residential Joint Venture Task Force homeowner survey da ta (2003), to inform reasonable assumptions regarding various applica tions and information related to ur ban/residential use. Due to the limited data available, exposure to the envir onment and uncertainties wi ll be characterized. Detailed information on non-agricultural use and usag e of pyrethrins products would be useful in
order to reduce those uncertainties for the fina l environmental ecologic al risk assessment for pyrethrins.

For indoor uses, the Division has conducted enviro nmental risk assessments for a few chemicals for Reregistration Eligibility Decisions ( e.g. , resmethrin and permethrin). The pyrethrins were among the chemicals assessed. At the time, there were no exceedances of any of the LOCs. In one study (Weston and Lydy, 2010), several syntheti c pyrethroids were ob served in effluents after secondary treatment from POTWs in the Sacramento-San Joaquin Delta. In the study, bifenthrin was the most frequently detected pyrethroid from municipal wastewater treatment plant effluents (POTWs) tested in the Sacramento -San Joaquin Delta (18 samples tested), and it
exceeded the Hyalella azteca EC 50 . Based on the above informa tion, there is the potential for pyrethrins to reach surface waters via exposure from contaminated drains, ev en after treatment in wastewater plants (POTWs). Thus, EFED conducted a prelim inary assessment of the indoor uses of pyrethrins using highl y unrefined usage information and found no ecological risks of concern ( i.e. , all RQs were below the acute and chroni c LOCs). The Division will evaluate the potential for exposure to aquatic organisms from the indoor uses of pyrethrins, using refined usage information and new endpoint s (if any) developed by the re gistrant in the registration review ecological risk assessm ent (for further details see Section 6 , Conceptual Model, Section
7 , Analysis Plan and Appendix C ).

Pyrethrins Use with Synergists Toxicity data on environmental mixtures of pyrethr ins with other pesticides may be presented, if available, as part of the ecological risk assessmen t. It is expected th at the toxic effect of pyrethrins, in combination with other pesticides used in the environment, is likely to be a function of many factors including but not necessarily limited to: (1 ) the exposed sp ecies, (2) the co-contaminants in the mixture, (3) the ratio of pyret hrins and co-contaminant concentrations, (4)

29differences in the pattern and duration of expos ure among contaminants, and (5) the differential effects of other physical/ chemical characteristics of the receivi ng waters, such as organic matter present in sediment and suspended water. Quantit atively predicting the combined effects of all
these variables on mixture toxic ity to any given taxa with c onfidence is beyond the capabilities of the available data and methodologies. However, a discussion of implications of the available pesticide mixture effects data regarding the confidence of risk assessment conclusions will be addressed as part of the uncertainty analysis . EFED will consider open literature, currently available models and other lines-of-evidence ( e.g. , monitoring data), as available to address the potential for cumulative effects of pyrethrins a nd pyrethroids in the ri sk description of the ecological assessment for pyrethrins.

Piperonyl butoxide (PBO) and MGK-264 are commonly used in fo rmulations with pyrethrins and pyrethroids. PBO acts as a potentiator in both mammals and insects because the pyrethroid is not metabolized and excreted as quickly in its presence (Stewa rt 1998). MGK-264, another potentiator/synergist used with pyr ethroids, has similar effects as those observed for piperonyl butoxide (US EPA 2006a).

Currently, data on the extent to which the to xicity of pyrethrins and pyrethroids active ingredients are enhanced by varyin g concentrations of PBO are needed to address the ecological risk of products when co-applied with PBO. The Agency is currently evaluating a proposed study protocol that will quantify the enhancemen t of acute toxicity of pyrethroids to the freshwater amphipod, Hyalella azteca , by simultaneous exposure to PBO at varying PBO:pyrethroid ratios. It is e xpected that this comprehensive testing strategy, when augmented with similar acute toxicity data with freshw ater fish and other selected pesticide active ingredients, will facilitate bridgi ng of the synergist toxicity enhancement to other co-formulated or co-applied pesticide/synergist ac tive ingredients that are not test ed at varying synergist:active ingredient ratios. The need for s ynergist data is discussed in the EFED Registration Review Problem Formulation for Piperonyl Butoxide , dated December 13, 2010 (USEPA, 2010, D378420). The PBO Problem Formulation is availa ble in the PBO registra tion review docket at www.regulations.gov (EPA-HQ-OPP-2010-0498).

With respect to pyrethrins ecological data, multip le aquatic toxicity studies were previously submitted for a pyrethrins end-use product contai ning 6% pyrethrins and 60% PBO. Data are
available for freshwater and estuarin e/marine fish and invertebrates (see Section 4. Receptors ). This data will be considered in the upcoming ecol ogical risk assessment for pyrethrins, as well as any additional applicable inform ation that is generated through the comprehensive PBO testing strategy.

3.3. Environmental Fate and Transport

Table 3.10 summarizes the environmental fate/transport properties of pyrethrin. For information about the physicochemical properties of this compound, refer to Table 3.2.

30Table 3.10. Summary of Environmenta l Fate Properties for Pyrethrin

Study Value and unit Major Degradate Minor Degradates MRID # or
Citation Classification of Study

Abiotic Hydrolysis

25±1 ° C Half-life 1 = pH 5 no evidence of degradation pH 7 no evidence of degradation pH 9 14 days Major degradate : chrysanthemic acid (53.9– 64.5% at 21–30 days at pH 9) 43188201

Acceptable Half-life 1 = pH 5 no evidence of degradation pH 7 no evidence of degradation pH 9 17 days Major degradate : chrysanthemic acid (54– 64% at 21 days, and was 60–62% at 30 days). Also a
dimer derived from the hydrolysis product pyrethrolone (MW=320), identified as the single main alcohol-derived degradate, in a parallel test at pH 9. 43567502

Direct Aqueous Photolysis (pH 7,
irradiated with sunlight in Irvine, CA) Half-life 1 = ~1 hr for the isomerization 11.8 hours, for the combination of pyrethrin and the (E)-Isomer of pyrethrin 1 Major degradate : (E)-isomer of pyrethrin 1(50.7–55.7% AR at 2 hr)
More than 24 minor products (<10%) 43096601,
43567601 Supplemental

Soil Photolysis (natural sunlight from
California at 24±2 ° C) Half-life = <1 day in a sandy loam Numerous minor degradation products (<10% AR) 43096602 Supplemental

Atmospheric Degradation Half-life 1 = 0.036 days for hydroxyl radical 0.012 days for ozone reaction N/A EPISuite
v.4.0 N/A

Aerobic Soil Metabolism (at 75% of
0.33 bar moisture at

25±1 ° C) Half-life 1 = 9.5 days sandy loam from ND Major unidentified : Reg-3 (29.7% at 3 days) Minor degradate : chrysanthemic acid (4.0% at 3 days) 43499803 Supplemental

Aerobic Aquatic Metabolism (25±1 ° C) Half-life 1 = Flooded sandy loam soil: 10.5 days for the total system (study lasted only 30 days) In the water, the parent at 7.6% initially and was last detected at 14 days with 0.4% AR Major degradate : Water: chrysanthemic acid (11.5–14.0% at 14–30 days) Sediment: chrysanthemic acid (8.1% at 14 days) 43499802 Supplemental

31Table 3.10. Summary of Environmenta l Fate Properties for Pyrethrin

Study Value and unit Major Degradate Minor Degradates MRID # or Classification
Citation of Study

Anaerobic Aquatic Metabolism (25±1 ° C) Half-life 1 = Flooded sandy loam soil: 86 days The parent compound was not detected in the water phase. Major degradate : Water phase: Chrysanthemic acid (10.3% AR at 90 days) Chysanthemum dicarboxylic acid (14.2% AR, 364 days) In the sediment phase, Jasmolin-1 (10.0% AR at 364 days) Chrysanthemic acid ( 7.0% AR, single replicate, at 3 days) and other minor unidentified degradates (each ≤ 6.6% AR)

14 CO 2 (13.49% AR at 364 days) 43499801 Supplemental

Freundlich solid-water
distribution coefficient (K F ) All soils were domestic.

K F , 1/n, soil texture 198 L/kg, 1.10, sand 268 L/kg, 0.91, sandy loam 430 L/kg, 1.05, silty loam 310 L/kg, 0.92, silty clay loam
Mean K F = 301.5 L/kg Note: Inspection of the data
shows that the K F model represents the mobility of pyrethrin 1 better than K FOC

. N/A 43096603 Acceptable

Freundlich organiccarbon normalized
distribution coefficient (K FOC ) K FOC , 1/n, soil texture 37847 L/kg, 1.10, sand 12472 L/kg, 0.91, sandy loam 74175 L/kg, 1.05, silty loam 16190 L/kg, 0.92, silty clay
loam Note: Inspection of the data
shows that the K F model represents the mobility of pyrethrin 1 better than K FOC

. N/A 43096603 Acceptable

Volatility from Soil (Laboratory)
50–75% of field moisture capacity Limited volatility, ≤ 0.002

μ g/cm 2 ·hour from Mutchler sandy loam soil. Maximum
mean air concentrations were
5.839–7.316 μ g/m 3

. After 30 days, volatilized
residues totaled a maximum
of ~16% of which ~9% was
CO 2 , ~0.3% was pyrethrin, ~10% chrysanthemic acid,
and ~ ≤ 2.4 of two minor degradates. 43096604 Acceptable

Terrestrial Field Dissipation Dissipation Half-life 1,2 = Bare plots of sandy loam soils in Porterville, CA, Pinehurst, GA, and Mason, MI: ~1-2 days NA 42745501 Supplemental

32Table 3.10. Summary of Environmenta l Fate Properties for Pyrethrin

Study Value and unit Major Degradate Minor Degradates MRID # or Classification
Citation of Study

Bioconcentration Factor (BCF) – Bluegill Sunfish ( Lepomis
macrochirus ) Water temp. 17 0 C Mean or Steady State BCF= 873X viscera; 127X edible tissues; 471x whole fish. Depuration was rapid; by day 1,
77% of the accumulated [ 14 C]residues were eliminated from the edible tissues, 66% from the nonedible tissues, and
68% from the whole fish. In the edible tissue, of the extracted radioactivity pyrethrin 1 was
56.4% and 19.6% in the
nonedible tissue. Major degradates : In the edible tissue, chrysanthemic acid was 29.5%, and three Unknowns
totaled 23.2%. In the nonedible tissue, chrysanthemic acid was 32.9%, and five Unknowns
totaled 21.8%. 43302301,
43884102 Acceptable

Abbreviations: wt=weight; NA=Not Av ailable; N/A=Not Applicable. 1 Half-lives were calculated using the singlefirst order equation and nonlinear regression, unless otherwise specified. 2 The value may reflect both dissipation and degradation processes.

Pyrethrin is a naturally occurring substance that c ontains six esters that are biologically active. As it has been said earlier, all the pyrethrins have the same backbone structure, with the exception of variations in the subs titutions in the external or out ermost groups. Due to the fact that all the pyrethrins have very similar struct ures, the environmental fate studies were conducted and well characterized with only on e of the pyrethrins: pyrethrin 1. Diastereoisomers could have somewhat different basic properties. In this case the differences are in the substituents at two sites. The substituents at -R are expected to ha ve low reactivity, with the ethene being slightly more reactive. In any case, the driving fate reaction is the breaking of the ester bond which is away from -R. On the other ha nd, in the case of -R’, we have two different moieties. The methyl moiety will be relatively unreactive, while the acetyl group (ester bond) will be susceptible to hydrolysis, resu lting in an acid and an alc ohol. It is noted from the Table 3.2 that the water solubility of the various pyrethrins varies due to some structure variations among them, however, since the environmental fate of only pyrethrin 1 was characterized, its solubility will be used in the models. This may add some uncerta inty to the final ecological risk assessment. Nevertheless, EFED does not e xpect major differences in th e overall biotic and abiotic degradation of the pyrethrins.

In general, the environmental fate and transport data base of pyrethr in 1 is adequate to characterize the environmental fate, drinking wate r, and ecological exposur e of the pyrethrins. There are no mobility and little persistence data for the degradates of pyrethrin 1. In addition, studies using radiolabeling on the cyclopentene si de of the ester linkage were not conducted and cold analysis was not performed in the cyclope ntene labeled studies (w ith the exception of one study of hydrolysis). Consequently, there was no an alysis of potential de gradates containing the cyclopentene ring originating from the cl eavage of the carboxylate ester linkage.

Degradation and Metabolism

Pyrethrin 1 was relatively stable in sterile aque ous pH 5 and pH 7 buffer solutions that were
incubated in the dark at 25 ° C for 30 days. In pH 9 solutions , pyrethrin 1 hydrolyzed with a

33calculated half-life of 14 days a nd 17 days in two separate st udies. The major degradation product identified was chrysanthemic acid at up to 64% of the applied at 21 days.

In an aqueous photolysis experime nt, pyrethrin 1 isomerized to the (E)-isomer of pyrethrin 1 (which reached a maximum 50.7–55.7% of the applie d amount at 2 hours post-treatment ) with an observed half-life of approximately 1 hour in ster ile solutions (pH 7) that were irradiated with sunlight in Irvine, California. Th e overall calculated ha lf-life of dissipation of pyrethrin 1 and its (E)-isomer was 11.8 hours. In a soil photolysis study [ 14 C]-pyrethrin photode graded with an observed half-life of <1 day. The registrant reported half-life was 12.9 hours. The test was conducted in sandy loam soil from ND that was treated at 9.0–9.6 ppm, and irradiated with natural sunlight in California at 24 ° C. In the irradiated soil, [ 14 C]-pyrethrin was 66.0-49.3% of the applied amount at 0 hours posttreatment, ranged from 42.8 to 59.0% at 1 through 4 hours, and was only 11.7-21.1 % at 24 hours. In contrast, the dark control samples degraded with a reported half-life of 82.9 hours (~3.5 da ys). In the dark control, [ 14 C]-pyrethrin comprised 66.7- 73.9% of the applied through 4 hours postt reatment, and was 57.6% at 24 hours.

The reported half-life of [ 14 C]-pyrethrin 1 applied at 1 ppm , in an aerobic sandy loam soil adjusted to 75% of field capacity and incubated in the dark at 25 ° C was 9.5 days. The degradation was reported as biphasic [half-liv es were 3.2 days (0–14 day data) and 23.5 days (14–59 day data)]. Chrysanthemic acid was a minor identified metabolite. Another band (which appears to consist of multiple peaks) could not be identified.

[ 14 C]-Pyrethrin 1 degraded with a half-life of 10.5 days in flooded sandy loam soil incubated at

25 ° C in an aerobic aquatic dissipa tion study. In an anaerobic aqua tic dissipation study the halflife of pyrethrin 1 was 86 days. The behavior of the system was reported to be bi-phasic (86 days being the half-life for the total system and 27.8 days for 0–31 da y data). In both instances, chrysanthemic acid was reported as a major meta bolite. Also, chysanthemum dicarboxylic acid was reported at a maximum of 14.2% AR at 364 da ys, and in the sediment phase, jasmolin-1 was 10.0% AR at 364 days.

It is noted that in all the studies, the material was radiolabeled in the cyclopropane ring. As a result, the degradate that is most likely to be observed is chrysanthemic acid. Material radiolabeled in the cyclopentenolone ring woul d result in different degradation products; however, the first step in the degradation of pyr ethrin 1 is the ruptur e of the ester bridge, resulting in a carboxylic aci d, and an alcohol. The resulting mol ecules are expected to lose their pyrethroid toxicological activity; therefore, in th e final ecological risk assessment, they will not be considered of concern. Furthermore, the av ailable data show that chrysanthemic acid does not reach high levels except upon hydrolysis at pH 9. In the many of the studies multiple degradates at very low concentrations were observed, but not characterized. The only significant isomer observed in the aqueous photolysis study was the (E)-isomer of pyrethrin 1; however, the halflife of pyrethrin 1 was reported for the photolysis of pyrethrin 1 plus the isomer (as if it was parent) in the calculation (the resulting half-lif e was less than one day).

Soil Sorption and Mobility

Based on batch equilibrium experiments, [ 14 C]pyrethrin 1 was noted to have a relatively low

34mobility in sand, sandy loam, silt loam and silty clay loam soil:calcium chloride solution slurries (1:100, w:v). The mean K F value was 301.5 L/kg.

Field Dissipation

A study, providing marginally supplemental data (bare ground soils in CA, GA, and MI) appears to indicate that dissipation in the field is ve ry rapid (~1-2 days). The test substance was pyrethrum extract (mixture of pyrethrins I and pyreth rins II). The results appear to confirm what would be expected from the laboratory studies.

Potential transport mechanisms for a pesticide include surface water r unoff, spray drift, and secondary drift of volatilized or soil-bound residues leading to deposition onto nearby or more distant ecosystems. Surface water runoff and spray drift are expected to be the major routes of exposure for pyrethrins to non-target organisms. The magnitude of transport via secondary drift depends on the pyrethrins’ ability to be mobilized into air and its eventual removal through wet and dry deposition of gases/ part icles and photochemical reactions in the atmosphere. Therefore, physicochemical properties of pyrethr ins that describe it s potential to enter th e air from water or soil ( e.g., Henry’s Law constant and vapor pressure), pesticide use data, modeled estimated concentrations in water and air, and available air monitoring data are considered in evaluating the potential for atmospheric trans port of pyrethrins. Pyrethrins have a moderately low vapor pressure (2.03 x 10 -5 torr) and a low Henry’s Law constant (7.7x10 -7 atm-m 3 /mol); thus, volatilization from water and soil surfaces is expect ed to be very low. Pyrethrins’ potential for
volatilization is also reduced si gnificantly because it adsorbs strongly to soils. Pyrethrins’ estimated atmospheric half-life is short (~0.04 days for the hydroxyl radical reaction), indicating a low potential for transport via volatilized active substance (as opposed to present in suspended solids).

4. Receptors

4.1. Aquatic and Terrestrial Effects

The receptor is the biological entity that is exposed to the stressor (EPA, 1998). Due to the outdoor uses of pyrethrins, the types of receptors that may be exposed include both aquatic and terrestrial receptors, such as birds, rep tiles, mammals, amphibians, freshwater and estuarine/marine fish, non-target terrestrial & aquatic invertebrates and terrestrial & aquatic plants. The stressor in this case is the pyrethrin pesticide. Spra y drift and runoff exposures are expected for both ground and aerial applications of pyrethrins. Consis tent with the process described in the Overview Document (USEPA, 2004), this risk assessment uses a surrogate species approach in its evaluation of pyrethrins. Toxicological data genera ted from surrogate test species, which are intended to be representati ve of broad taxonomic groups, are used to extrapolate to potential effects on a variety of species (receptors) in cluded under these taxonomic groupings.

Tables 4.1 and 4.2 provide a summary of the taxonomic gr oups and the surrogate species tested to help understand potential acute and chronic ecological effects of pyrethrins to these non-target taxonomic groups.

35Terrestrial Species

For terrestrial species, data were submitted for both pyrethrum extract. In addition, mammalian toxicity studies with end-use products containing pyrethrins and the synergist PBO. A summary of the most sensitive endpoints fr om the available toxicity studies conducted with aquatic species is presented in Table 4.1 and the mammalian end-use product data is summarized in Table 4.2

.

Table 4.1 Summary of most sensitive endpoints from subm itted terrestrial toxicity studies for pyrethrins. Species (common

name) Taxa Represented Endpoint Concentration Test
Substance

(% a.i.) Reference Acute Toxicity
Classification

Rattus norvegicus (Laboratory Rat) Mammals LD 50 1400 mg/kg bw 58 (pyrethrum

extract) 42008101 Acceptable Slightly toxic

NOAEL 6.4 mg ai/kg bw/day 58 (pyrethrum

extract) 41327501 Acceptable Not Applicable LOAEL 65 mg/kg bw/day

Bobwhite quail ( Colinus virginianus )

Birds,
terrestrialphase amphibians, and reptiles LD 50 >2000 mg ai/kg bw 58 (pyrethrum

extract) 42010901 Acceptable Practically
non-toxic

Bobwhite quail ( Colinus virginianus )

Mallard duck ( Anas platyrhynchos ) LC 50 >5620 mg a.i./kg
diet 58 (pyrethrum

extract) 41968801 Acceptable

41968802 Acceptable Practically
non-toxic

NOAEC No data available Not Applicable LOAEC

Apis mellifera

(Honey bee) Terrestrial
invertebrates Contact

LD 50 0.022 μg a.i./bee 58 (pyrethrum

extract) 41968803 Acceptable Highly toxic

Birds The results of the single acute oral toxicity st udy available for pyrethrins (pyrethrum extract, 58% active ingredient) indicate that the chemical is practically non-toxic to avian species on an
acute oral basis. The acute oral LD 50 value for bobwhite quail ( Colinus virginianus ) is >2000 mg a.i./kg bw (MRID 42010901). At the 500, 1000 a nd 2000 mg ai/kg bw treatment levels, observations of toxicity effects included shallow and rapid resp iration, prostrate posture, lower limb weakness, loss of coordina tion, lethargy, hyperexcitability, reduced reaction to external stimuli, ruffled appearance and twitching. We ight loss was also observed at the 1000 and 2000 mg ai/kg bw, compared to the control birds. No acute dose-based exposure was estimated in the latest Agency ecological risk assessment fo r pyrethrins (USEPA 2007). However, based on a preliminary screen using the highest agricultu ral application scenario for pyrethrins (see Table
3.3 ), the highest peak dose-based EEC is 125 mg/kg bw. This conservative dietary exposure prediction is approximately 16 times lower than the highest treatment level tested in the available
acute oral test with bobwh ite quail, at which an LD 50 could not be establis hed due to lack of mortality.

36No acute avian oral studies with pyrethrins have been submitted for passerine species.

The results of the sub-acute dietar y toxicity studies available for pyr ethrins indicate that it can be classified as practically non-toxic to avia n species on an acute dietary basis. The LC 50 is greater than 5620 mg a.i./kg bw for bobwhite quail ( Colinus virginianus ) (MRID 41968801). In this study, the NOAEC was determined to be 3160 mg a.i./kg bw, based on reductions in body weight gain at the 5620 mg a.i./ kg bw treatment level. In a dietary study conducted with mallard ducks ( Anas platyrhynchos ), the LC 50 is also greater than 562 0 mg a.i./kg bw (MRID 41968802). The NOAEC in this study is 1780 mg a.i./kg bw, based on signs of lethargy. Both avian dietary studies were conducted with pyrethrum extract , 58% active ingredient. The highest peak predicted dietary exposure concentr ation for birds was 97 mg ai/kg bw, modeled in latest Agency ecological risk assessment for pyrethrins (USE PA 2007). Therefore, th e predicted dietary exposure for birds resulting from pyrethrins use a ppears to be at least 60 times lower than the highest treatment levels in the available avian dietary studies for pyrethrins, at which an LC 50 could not be established.

No avian reproduction studies have been submitted for pyrethrins.

Mammals Mammalian toxicity data submitted to the Agency's Health Effects Division (HED) are used to approximate toxicity to wild mammals. These studies are typically c onducted with laboratory rats ( Rattus norvegicus ) or mice ( Mus musculus ). No studies evaluating toxicity to wild mammal species have been submitted by the registrants for pyrethrins.

Acute oral, dermal and inhalation mammalian toxici ty studies with pyrethrins were submitted to the Agency. In addition, chronic dietary and 2-generation rat repr oduction studies have also been submitted for pyrethrins. These studies are presen ted in the HED chapter of the Reregistration Eligibility Decision Document (RED) for pyret hrins (US EPA, 2006). In addition, registrantsubmitted rat toxicity information for i ndividual products is also available.

The reported laboratory rat acute oral LD 50 value is 1400 mg/kg-bw for pyrethrins (MRID 42008101). The acute dermal LD 50 >2000 mg/kg bw for pyrethrins, based on a study conducted with rabbits (MRID 41964801). An acute inhalation conducted with rats resulted in an LC50 >3.4 mg/L for pyrethrins (MRID 42008002). Base d on these reported laboratory rat LD 50 values, pyrethrins have low to moderate acute toxicity to small mammals via the oral, dermal and
inhalation basis.

Additional rat acute oral data were available for crude pyrethrum extract, as well as a number of pyrethrins products. See Table 4.2 for an overview of the studies. Based on this subset of data for products containing pyrethrins or pyrethrins and PBO, mamma lian toxicity appears to be similar across products, ranging from prac tically nontoxic to slightly toxic.

Table 4.2. Rat acute oral toxicity data for crude pyrethrum extract and pyrethrins end-use products

Product Percent active ingredient LD 50 (mg/kg bw) Reference

37Crude pyrethrum extract not reported 787 mg/kg bw for females 2136 mg/kg bw for males MRID 45625301

Pyganic fogging

concentrate 5% pyrethrins ≥ 2000 mg/kg bw (females only) MRID 45848201

Pyrocide fogging

concentrate 5% pyrethrins, 25% PBO ≥ 500 and < 5000 mg/kg bw (both males and females) MRID 45647601

Pyrocide concentrate 3% pyrethrins, 30% PBO ≥ 500 and < 5000 mg/kg bw (both males and females) MRID 45807601

Pyrocide concentrated

aqueous spray 1% pyrethrins and 10%
PBO ≥ 2000 mg/kg bw (females only) MRID 45807701

In the available 2-generation rat reproducti on study, the NOAEL is 6.4 mg/kg/day based on decreased F1 pup body weight and body weight ga in during lactation at the 65 mg/kg/day treatment level (MRID 41327501). In the submitte d chronic mammalian dietary study with pyrethrins, the NOAEL is 4.37 mg/k g/day based on the increased incidence of follicular cell hyperplasia in male rats at the 42.9 mg/kg/ day treatment level (MRID 41559501). Because follicular cell hyperplasia is not clearly linked to the typical ecological endpoints of survival, growth and reproduction, the NOAEL of 6.4 mg/k g/day based on decreased F1 pup body weight in the 2-generation rat reproduction study is cons idered the most sensiti ve endpoint for risk
estimation at this time.

Terrestrial Invertebrates The Agency guideline terrestrial inve rtebrate tests are for honey bees ( Apis mellifera ). The acute

contact LD 50 value is 0.022 (with pyrethrum extract) (MRID 41968803). Based on these results, pyrethrins are classified as ‘h ighly toxic’ to honey bees on an acute exposure basis.

Aquatic Species

For aquatic species, data were submitted for both pyrethrum extract and an end-use product containing pyrethrins and the synergist PBO. In a ll situations where acute toxicity data with the same species were available for both pyrethrum extract and pyrethrins + PBO, the organisms were more sensitive to the pr oduct containing the synergist (LD 50 confidence intervals did not overlap). A summary of the most sensitive endpo ints from the available toxicity studies conducted with aquatic species is presented in Table 4.3

.

Table 4.3. Summary of most sensitiv e endpoints from submitted aquatic to xicity studies for pyrethrins.

Exposure
Scenario % Active Ingredient Species Exposure
Duration Endpoint Reference Acute Toxicity
Classification

Freshwater Fish

38Table 4.3. Summary of most sensitiv e endpoints from submitted aquatic to xicity studies for pyrethrins.

Acute Toxicity Exposure % Active Exposure Reference Species Endpoint Classification Scenario Ingredient Duration

Acute Pyrethrum

extract

57% Rainbow Trout

Oncorhynchus mykiss 96 hours LC 50 = 5.1 μg
a.i./L

NOAEC = 3.1 μg a.i./L MRID 43082303

Acceptable Very highly toxic

TEP

6% pyrethrins

60% PBO Rainbow Trout Oncorhynchus mykiss 96 hours LC 50 = 3.2 μg
a.i./L

NOAEC= 1.5 μg a.i./L MRID 43082304

Acceptable Very highly toxic

Chronic Pyrethrum

extract

57% Fathead minnow Pimephales promelas 30 days NOAEC = 1.9 μg a.i./L

LOAEC = 3.0 μg a.i./L MRID 43252701

Acceptable Not applicable

Freshwater Invertebrates

Acute Pyrethrum

extract

57% Water flea Daphnia magna 48 hours EC 50 = 11.6 μg
a.i./L

NOAEC=3.7

μg a.i./L MRID 43082305

Acceptable Very highly toxic

TEP

6% pyrethrins

60% PBO Water flea Daphnia magna 48 hours EC 50 = 6.7 μg
a.i./L

NOAEC = 0.5 μg a.i./L MRID 43082305 Acceptable Very highly toxic

Chronic Pyrethrum

extract

57% Water flea Daphnia magna 35 days NOAEC = 0.86 μg a.i./L

LOAEC = 2.0 μg a.i./L MRID 43252702

Acceptable Not applicable

39Table 4.3. Summary of most sensitiv e endpoints from submitted aquatic to xicity studies for pyrethrins.

Acute Toxicity Exposure % Active Exposure Reference Species Endpoint Classification Scenario Ingredient Duration

Acute Pyrethrum

extract

57% Sheepshead
minnow Cyprinodon variegatus 96 hours LC 50 = 16 μg
a.i./L

NOAEC = 7.4 μg a.i./L MRID 43082307

Acceptable Very highly toxic

TEP

6% pyrethrins

60% PBO Sheepshead
minnow Cyprinodon variegatus 96 hours LC 50 = 3.8 μg
a.i./L

NOAEC = 1.6 μg a.i./L MRID 43082308

Acceptable Very highly toxic

Chronic No data available

Estuarine/Marine Invertebrates

Acute Pyrethrum

extract

57% Saltwater mysid Americamysis
bahia 96 hours LC 50 = 1.4 μg
a.i./L

NOAEC=0.29 μg a.i./L MRID 43082311 Acceptable Very highly toxic

TEP

6% pyrethrins

60% PBO Saltwater mysid Americamysis
bahia 96 hours LC 50 = 0.14 μg
a.i./L

NOAEC = 0.084 μg a.i./L MRID 43082312 Acceptable Very highly toxic

Chronic No data available

Freshwater Fish

The acute toxicity studies avai lable to the Agency demonstrat e that pyrethrins (pyrethrum extract) can be classified as very high ly toxic to freshwater fish. The acute LC 50 value is 5.1 μg
a.i./L for rainbow tr out and the acute LC 50 value is 10 μg a.i./L for bluegill sunfish (MRIDs 43082303 and 43082301). Both endpoints are based on mean-measured concentrations of pyrethrins active ingredient.

The previously submitted studies also demonstrate that pyrethrins products formulated with the synergist PBO are more toxic than the pyrethrum extract to freshwater fish , but within an order of magnitude difference. The toxi city observed in acute freshwater fish toxicity studies with Pyrenone Crop Spray (6% pyrethrins and 60% PBO) resulted in an LC 50 value of 3.2 μg a.i./L
for rainbow trout and an LC 50 value of 3.4 μg a.i./L for bluegill sunfish (MRID 43082304 and

4043082302). Both endpoints are based on mean-measur ed concentrations of pyrethrins active ingredient.

An acceptable 30-day early-life st age study with fathead minnows ( Pimephales promelas ) was submitted to evaluate the effects of chronic exposure to pyrethrins on freshwater fish (MRID 43252701). The study demonstrated that chronic exposur e to concentrations as low 3.0 μg a.i./L has the potential to cause repr oductive toxicity, based on a signi ficant reduction in the number of eggs hatched and body weight in the 3.0 μg a.i./L treatment level relative to the controls (73% vs. 87% for egg hatch; 0.29 mg vs. 0.33 mg fo r body weight). The NOAEC for this study is 1.9 μg a.i./L.

No freshwater fish full life cycle study has been submitted for pyrethrins.

Estuarine/Marine Fish

The acute toxicity studies availa ble to the Agency demonstrate th at pyrethrins can be classified as very highly toxic to estuarine/marine fish. Expo sure to pyrethrum extract resulted in an acute
LC 50 value of 16 μg a.i./L for sheepshead minnow, and pyrethrins formulated with PBO yielded
an acute LC 50 value of 3.8 μg a.i./L for sheepshead minnow in a submitted toxicity test (MRIDs 43082307 and 43082308).

No estuarine/marine fish full life cycle study has been submitted for pyrethrins.

Freshwater Invertebrates

The acute toxicity studies availa ble to the Agency demonstrate th at pyrethrins can be classified as very highly toxic to freshwa ter invertebrates. The acute EC 50 value for pyrethrins (pyrethrum extract, 57% active ingredient) is 11.6 μg a.i./L based on a test with waterfleas ( Daphnia magna ) (MRID 43082305). Another submitted study with Daphnia magna indicates that pyrethrins formulated with PBO has greater toxicity than pyrethrins alone, with an EC 50 of 6.7 μg a.i./L (MRID 43082306).

In addition to the registrant-submitted studies fo r pyrethrins, one acute freshwater invertebrate toxicity test conducted by the U.S. Fish a nd Wildlife Service (1969) is available (MRID 05009242). Based on the overview provided, a st udy conducted with pyrethrum (active ingredient not reported) exposure to scuds ( Gammarus lacustris ) resulted in a 96 hour LC 50 of 12 μg a.i./L. The results of this study indicate a similar response between daphnids and amphipods to pyrethrins exposure. However, no additional details on test conditions , raw data and data analysis are available for this study, so the test is considered supplemental information for the upcoming risk assessment.

41An acceptable guideline life-cycle studies with waterfleas ( Daphnia magna ) reports a NOAEC of 0.86 μg a.i./L for pyrethrins (pyrethrum extract, 57% active ingredient. The LOAEC for this study is 2.0 μg a.i./L, based on reductions in th e number of young produc ed per female (MRID 43252702).

In addition to studies submitted that examine the e ffects of pyrethrins to aquatic invertebrates in the water column, a 28-day benthic invertebrate study with the midge Chironomus riparius has been submitted to the Agency (MRID 48141101, in review). This study was conducted with sediment spiked with pyrethrum extract, and conducted in accordance with OECD Guideline
218: Sediment-Water Chironomid Toxici ty Test Using Spiked Sediment . Percent emergence and development rate were calculated, and emergence rate was determined to be statistically lower than the controls at the highe st nominal treatment level, 1000 mg a.i./kg sediment (49% emergence in this treatment compared to 74% in the negative control). There is substantial uncertainty in using the results of this study quantitatively in the upcoming ecological risk assessment, as the measured concentrations in th e sediments were 10 to 17% of the nominal test concentrations on Day 0, and the measured levels of pyrethrins fell to <3 to 5% by Day 28. In addition, this study did not exam ine reproductive parameters.

Estuarine/Marine Invertebrates

The acute toxicity studies availa ble to the Agency demonstrate th at pyrethrins can be classified as very highly toxic to estuarine/marine invertebrates. A submitted study with pyrethrum extract (57% active ingredient ) and mysid shrimp ( Mysidopsis bahia ) resulted in an LC 50 value of 1.4 μg a.i./L (MRID 43082311). Based on an additional submitted study with pyrethrins formulated with PBO (6% pyrethrins; 60% PBO), showed in creased sensitivity to the product, with an LC 50 value of 0.14 μg a.i./L (MRID 43082312)

Pyrethrins appear to be less toxic to estuarin e/marine bivalves than shrimp, based on submitted studies with the eastern oyster ( Crassostrea virginica ). For bivalves, the EC 50 value is 86 μg a.i./L for pyrethrum extract and 26 μg a.i./L for formulated pyrethrins with PBO (MRIDs 43082309 and 43082310).

No chronic full life cycle study with estuarin e/marine invertebrates has been submitted for pyrethrins.

Plants

No studies evaluating the toxicity of pyrethrins to terrestrial plants , aquatic plants or algae have been submitted to the Agency.

ECOTOX Available open literature will be used to evaluate the potential direct effects of pyrethrins to the terrestrial receptors iden tified in this section. Th is includes toxicity data on the technical grade active ingredient, and when avai lable, formulated products.

42At this time, a full and complete ECOTOX search has not been performed, but will be conducted prior to the final risk assessment. The open lite rature studies will be identified through EPA’s ECOTOX database ( http://cfpub.epa.gov/ecotox/ ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and wildlife. The evaluation of data can also provide insight into the direct and indirect effects of pyrethrins on biotic communities from loss of species that are sensitive to the chemical and from changes in structure
and functional characteristics of the affected communities.

Open literature toxicity data for other ‘target’ insect species (not including bees, butterflies, beetles, and non-insect invert ebrates including soil arthropods and worms), which include efficacy studies, are not currently considered in deriving the most sensitive endpoint for terrestrial insects. Efficacy studi es do not typically provide endpoi nt values that are useful for risk assessment (such as NOAEC, EC 50 , etc.), but rather are inte nded to identify a dose that maximizes a particular effect (such as EC 100 ). Therefore, efficacy data and non-efficacy toxicological target insect data will not be included in the ECOTOX open literature search.

4.2. Incident Database Review

A review of the Ecological Incident Informa tion System (EIIS, v. 2.1) and Aggregate Incident databases for ecological incidents involving pyrethrins was completed on September 1, 2011. This database consists of exposure incident reports submitted to the EPA from 1994 to present. A search for incidents involving pyr ethins was also conducted in th e American Bird Conservancy’s Avian Incident Monitoring System (AIMS).

The reports are listed in order of certainty, from highly probable to unrelated. Incidents listed in EIIS are categorized by the likelihoo d that a particular pesticide is associated with that particular
incident. These classifications in clude highly probable, probable, possible, unlikely or unrelated. “Highly probable” incidents usually require carcass residues or cl ear circumstances regarding the exposure. “Probable” incidents include those where residue info rmation was not available or circumstances were less clear than those for “hig hly probable”. “Possible” incidents occur when multiple chemicals may have been involved and the contribution of an individual chemical is not obvious. An “unlikely” incident classification is given when a given chemical is considered nontoxic to the type of organism involved or the chemical was analyzed and not detected in samples. The “unrelated” category is used for in cidents confirmed not to involve pesticides.

The number of reports listed in the EIIS database is believed to be only a small fraction of the total incidents involving organism mortality and damage caused by pesticides. Few resources are assigned to incident reporting. Reporting by states is only volu ntary, and individuals discovering incidents may not be informed on the procedure of reporting these occu rrences. Additionally, much of the database is generated from regi strant-submitted incident reports. In addition, incident reports for non-target organisms typical ly provide information only on mortality events and plant damage incidents. Except for phytotoxic effects in terrestrial pl ants, sublethal effects for organisms such as reduced growth or impa ired reproduction are rarely reported. Because of these logistical difficulties, EIIS is most likel y a minimal representation of all pesticide-related ecological incidents.

43Registrants are legally required to provide detailed reports of only “major” ecological incidents involving pesticides, while “minor” incident s are reported aggregately. Based on 40 CFR §159.184, an ecological incident is considered major and must be submitted to the Agency by the registrant if any of the following criteria are met:

Fish or wildlife: (A) Involves any incident caused by a pe sticide currently in Formal Review 4 for ecological concerns. (B) Fish: Affected 1,000 or more individua ls of a schooling species or 50 or more individuals of a non-schooling species. (C) Birds: Affected 200 or more individuals of a flocking species, or 50 or more individuals of a songbird species, or 5 or mo re individuals of a predatory species. (D) Mammals, reptiles, amphibians: Af fected 50 or more individuals of a relatively common or herding species or 5 or more individuals of a rare or solitary species. (E) Involves effects to, or illegal pesticide treatment (misuse) of a substantial tract of habitat (greater than or equal to 10 acres , terrestrial or aquatic).
Plants : (A) The effect is alleged to have occurre d on more than 45 percent of the acreage exposed to the pesticide.

The EIIS database contained 7 major incident s involving pyrethrins. The reports included 2 fish incidents and 5 plant incidents. In respect to the likelihood that pyrethrins caused the reported incidents, the certainty ranged from po ssible to probable. No unrelated or unlikely incidents were listed in EIIS for pyrethrins. Four of the incidents resulted from registered uses, two were misuses and one use pattern is unknow n. A summary of ecologi cal incidents involving pyrethrins included in the EIIS database are listed in Appendix B

.

The AIMS database contains no avi an incidents involving pyrethrins.

All other incidents are classified as ‘minor’. All ecological incide nts classified as ‘minor’ only need to be aggregately reported as quarterly coun ts of incidents by the re gistrant(s). Ecological incidents reported in aggregate re ports include those categorized as ‘minor fish and wildlife’ (WB), ‘minor plant’ (P-B), and ‘other non-target ’ (ONT) incidents. ‘Oth er non-target’ incidents include reports of adverse e ffects to insects and other terrestrial invertebrates. For pyrethrins, the registrants have reported 231 minor plant incidents. All reported incidents occurred between 1995 and 2010, and involved currently registered products such as Ortho Rose and Flower Insect Killer, Ortho Toma to and Vegetable Insect Killer , Real Kill Rose and Garden Insect Spray and Pyganic 5.0, among others. Unle ss additional information on these aggregated incidents becomes available, they will be assumed to be representative of registered uses of pyrethrins in the risk assessment.

4 Formal Review means Special Review, Rebuttable Presumption Against Registration (RPAR), FIFRA section 6(c) suspension proceeding, or FIFRA sectio n 6(b) cancellation proceeding, whether completed or

not.

444.3. Ecosystems Potentially at Risk

Pyrethrins may be applied on a variety of food/f eed crops, including (but not limited to), alfalfa, nut trees, corn, leafy vegetables, stone fru its, pome fruits, fruiting vegetables, cucurbit vegetables, cole crops, onion and soybean. In addition, they may be us ed on numerous non-food sites ( e.g. ornamentals, commercial animal housing, outdoor agricultural pr emises, residential sites – outdoors, outdoor eating establishments, and as an adulticide or mosquito control). Thus, the ecosystems at risk may be extensive in sc ope, and as a result it may not be possible to identify specific ecosystems during the developmen t of a baseline risk a ssessment. In general terms, terrestrial ecosystems potentially at risk due to the use of pyrethr ins, could include the treated field and areas immediately adjacent to the treated field that may receive drift or runoff. Areas adjacent to the treated field could include cultivated fields, fencerows and hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats and other uncultivated areas. Due to the potential persistence of pyrethrins under certain circumstances, it is expected to drift and/ or runoff due to application to food crops and certain non-crop sites, resulting in possible exposure to aquatic ecosystems. Aquatic ecosyst ems potentially at risk due to the use of pyrethrins include water bodies ad jacent 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 hab itat also includes marine ecosystems, such as
estuaries.

5. Assessment Endpoints

Assessment endpoints are defined as “explicit expressions of the actual envir onmental value that is to be protected.” Defining an assessment e ndpoint involves two steps: 1) identifying the
valued attributes of th e environment that are considered to be at risk; and 2) operationally defining the assessment endpoint in terms of an ecological entity ( i.e. , a community of fish and aquatic invertebrates) and its attributes ( i.e. , survival and reproduction). Therefore, selection of the assessment endpoints is ba sed on valued entities ( i.e. , ecological receptors), the ecosystems potentially at risk, the migration pathways of pesticides, and the routes by which ecological receptors are exposed to pesticide-related cont amination. The selection of clearly defined assessment endpoints is important because they provide direction and bou ndaries in the risk assessment for addressing risk management issues of concern. Changes to assessment endpoints are typically estimated from the available toxici ty studies, which are used as the measures of effects to characterize potential ecological risks associated with exposure to pesticides, such as pyrethrins.

To estimate exposure concentrations, the ecological risk assessment considers applications at the maximum application rate to fields that have vu lnerable soils. The most sensitive toxicity endpoints are used from surrogate test species to estimate treatment-re lated direct effects on acute mortality and chronic reproductive, growth and survival assessment endpoints. Toxicity
tests are intended to determine e ffects of pesticide exposure on bi rds, mammals, fish, terrestrial and aquatic invertebrates, and plants. These tests include short-term acute, sub-acute, and

45reproduction studies and are typically arranged in a hier archical or tiered system that progresses from basic laboratory tests to appl ied field studies. The toxicity studies are used to evaluate the potential of a pesticide to cause adverse effects, to determine wh ether further testing is required, and to determine the need for precautionary labe l statements to minimize the potential adverse effects to non-target animals and plants.

An open literature search will be conducted to determine any relevant endpoints. The search will focus on survival, growth and reproductive eff ects for aquatic and terrestrial effects of pyrethrins. More sensitive endpoints from accepta ble open literature studies will be included in the ecological risk assessment.

6. Conceptual Model

For a pesticide to pose an ecological risk, it mu st 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 recepto r. For an ecological pathway to be complete, it must have a source, a release mechanism, an environmental transport medium, a point of exposure for ecological receptors, an d a feasible route of exposure.

A conceptual model provides a written descriptio n and visual representation of the predicted relationships between pyrethrins, potential routes of exposure, a nd the predicted effects for the assessment endpoint. A conceptual model consists of two major components: risk hypothesis and a conceptual diagram (USEPA, 1998).

6.1. 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 (USEPA 1998). For th is assessment, the risk is stressor-initiated,
where the stressor is the releas e of pyrethrins into the environment. The following risk hypotheses are presumed for this screening-level assessment:

Pyrethrins, when used outdoors in accordance w ith registered labels, will likely lead to off-site movement of the compound via agricultural and urban runoff, spray drift, and eroded soil leading to exposure of nontarget plants and animals Based on information on the environmental fate, mode of action, dire ct toxicity and potential indirect effects, EFED assumes that registered uses of pyre thrins have the potential to cause reduced survival, growth, and reproduction to non-target terrestrial and/ or aquatic animals and plants.

Pyrethrins, when used indoors for uses such as pet shampoos, etc ., in accordance with current labels, will likely result in off-si te movement of the compound via wash-off into surface waters via drains and municipal wa stewater treatment plants, leading to exposure of nontarget aquatic plants and anima ls. This potential exposure pathway may result in adverse effects upon the survival , growth, and/or reproduction of non-target aquatic animals and plants.

46Pyrethrins, when used for the treatment of cattle (and certain other animals), in accordance with current labels, may result in off-site movemen t of the compound via wash-off of cattle and calves into surfa ce waters, leading to exposure of nontarget aquatic plants and animals. This potentia l exposure pathway may result in adverse effects upon the survival, growth, and/or re production of non-target aquatic animals and plants.

The conceptual model is a generic graphic depi ction of the risk hypothesis. It includes the potential pesticide or stressor (pyrethrins and pos sible metabolites, as well as synergists), the source of the pesticide and/or transport pathways, exposure me dia, exposure point, biological receptor types, and attribute changes.

6.2. Conceptual Diagram

The conceptual model is a generic graphic depict ion of the risk hypothesis, and assumes that the insecticide pyrethrins, which is a natural pyr ethroid insecticide, having multiple outdoor agricultural and non-agricu ltural uses, is capable of affecting aquatic a nd terrestrial animals provided that environmental concen trations are sufficiently elevated as a result of proposed label uses. Based on an examination of the physicoche mical properties of pyrethrins, the fate and disposition in the environment, and mode of application, a concep tual model was developed that represents the possible relati onships between the stressors, ecological recept ors, and the assessment endpoints. Through a preliminary iterat ive process of examining available data, the conceptual model ( i.e ., the representation of the risk hypothe sis) may be refined to reflect the likely exposure pathways and the organisms that are most relevant and applicable to this assessment ( Figures 6.1a and 6.1b ). They include the potential pe sticide or stresso r (pyrethrins, but the presence of toxicologically important metabolites and/ or s ynergists cannot be ruled out), the sources and/ or transport pathways, exposure media and expos ure points, biological receptor types and attribute changes.

In order for a chemical to pose an ecologica l risk, it must reach ecological receptors in biologically significant c oncentrations. 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 recep tors, and a feasible route of exposure. In addition, the potential mechanisms of degradation/ transformation ( i.e. , which degradation/ transformation products may form in the environm ent, in which media, and how much) must be understood, especially if for the chemical, its metabolit es/ transformation products are of greater toxicological concern than the parent com pound. The assessment of ecological exposure pathways, therefore, includes an examination of the source and pot ential migration pathways for constituents, and the determination of potential exposure routes.

Under the possible uses of pyrethrins, the sour ces and mechanisms of release of the compounds are from ground or aerial spray or ULV applications . Note that this conceptual model considers agricultural applications as well as certain non-ag ricultural applications. Surface runoff from the areas of application is assumed to depend on f actors such as topography, irrigation, and rainfall

47events. Direct deposition may result in contam ination of food items that may be consumed by terrestrial organisms. Spray dr ift results in contaminated adj acent areas, including bodies of water. Leaching to groundwater is not consider ed an important source because the pyrethrins, like many other pyrethroids, show low mobility in a va riety of soils. Pyrethrins appear to have a low potential for volatilization, wi th a low vapor pressure and Henr y’s Law Constants. Further, the hydroxyl radical reaction half- life for pyrethrins is ~0.04 days as estimated by quantitative structure-activity relationship (Q SAR) methods (EPI Suite v.4.0). The short (atmospheric) halflife, the low vapor pressure (~10 -5 to ~10 -7 torr) and relatively low Henry’s Law constant (~10 -7

to ~10 -8 atm/m 3 -mol), and its binding capacity, suggest that the potential for atmospheric transport for pyrethrins is relatively low and that this source of the chemical is of low importance, compared to spray drift, runoff and/ or direct contact after application.

For aquatic receptors, the major point of expos ure is through direct contact with the water column, sediment, and pore water (gill/ integumen t) contaminated with spray drift (from spray application) and/or runoff and flow ( e.g. , piped storm drains) from treat ed areas. Indirect effects to aquatic organisms (both fish and aquatic invertebrates) can also occur through impact to various food chains. The representative aquatic receptors are certain fres hwater and estuarine/ marine fish, invertebrates, and, in certain cases, aquatic plants. The major point of exposure for terrestrial animals is consumption of food contaminated with residue s such as grass, foliage, and small insects. For plants, the point of expos ure is direct contact or root uptake. The representative terrestrial receptors are mammals , birds and terrestrial plants. The attribute changes used to assess risk to terrestri al receptors depend on the type of test ( e.g. , reduced survival, growth, or reproduction for animals a nd seedling emergence and vegetative vigor for plants). It should be noted, that these species do not cover all th e possible species in the animal and plant kingdoms; certain taxa ar e considered as surrogates for other taxa. For example, fish are considered surrogates for aquatic phase amphibians.

This conceptual model also shows informati on about the potential fo r biomagnification for pyrethrins (see piscivorous birds and mammals in Fig. 6.1b ). The reported value of log octanol/ water partition coefficient of 4.3–5.9 (or K OW = 2.0 x 10 4 – 7.9 x 10 5 ) suggests that pyrethrins have the potential to bioaccumulate in aquatic organisms assuming that chemical metabolism is negligible. However, the measured bioconcentration factor in fish ( Table 3.11 ) is much lower than what would be expected based on K OW alone, which suggests that pyrethrins fish metabolism is substantial. Thus, it appear s that the potential for bioaccumulation/ bioconcentration in aquatic organisms and bioma gnification in terrestrial organisms is low.

Pyrethrins show a range of solubili ty of 0.2 to 9.0 ppm, a very high K OW and relatively high K F s and K FOC s. These properties suggest that the chem icals could partition with the sediments and particulate suspended in bodies of water. Pyrethri ns are likely to concen trate in the sediments, especially after repeated exposures (applications ), where they could pers ist. Such sediments could serve as repositories of the chemical for extended periods of time and could potentially be toxic to sediment dwelling organisms, affecti ng the food chain. These issues will also be assessed in the risk assessment for pyrethrins.

48Figure 6.1a. Aquatic conceptual model de picting stressors, exposure pathways, and potential effects to aquatic organisms from the use of pyrethrins on agricultural and certain non-agricultural sites

**Considered a minor route of exposure 

### Stressor

Source

Receptors

Attribute Change Pyrethrins applied to agricultural or non-agricultural use site

Spra y drif t

Aquatic animals
Invertebrates
Vertebrates Piscivorous mammals
and birds**

Individual organisms
Reduced survival (2) Reduced growth Reduced reproduction Food chain Reduction in algae and vascular plants Reduction in prey Modification of PCEs related to prey availability Habitat integrity Reduction in primary productivity Surface water/ S edimen t Runoff

Aquatic Animals
Invertebrates
Vertebrates 

### Exposure
Media

Uptake/gills or integument

In g estion Ingestion Atmospheric transport

Wet/dry deposition Soil Leaching to Groundwater

Uptake/gills or integument

Aquatic Plants
Non-vascular
Vascular Uptake/cell, roots, leaves Riparian plants
terrestrial

exposure pathways; see

Figure 6.1b Flow ( 1 ) Impervious Surfaces

Reduced cover Community change Modification of PCEs related to
habitat

1 Includes flow across vegetation and vegetated drainage systems ( e.g. , swales) and flow across impervious surfaces and through impervious (piped) storm drains.

2 Immobilization is considered equivalent to mort ality in toxicity tests for aquatic invertebrates.

Dotted lines indicate exposure pathways that have a low likelihood of contributing to ecological risk.

49Figure 6.1b. Terrestrial conceptual model de picting stressors, exposure pathways, and potential effects to terrestria l organisms from the use of py rethrins on agricultural and certain non-agricultural sites

Stressor

Source

Attribute Change Pyrethrins applied to agricultural or non-agricultural use sites

Direct application Spray drift

Terrestrial
vertebrates Terrestrial Exposure Media & Receptors

invertebrates

Individual organisms
Reduced survival Reduced growth Reduced reproduction Food chain Reduction in prey and food Modification of PCEs related to prey availability Habitat integrity Reduction in primary productivity
Reduced cover Community change Modification of PCEs related
to habitat Terrestrial plants grasses/ forbs, fruit, seeds (trees, shrubs) Runoff

Terrestrial
vertebrates Soil

Ingestion Ingestion Ingestion Dermal uptake/Ingestion Atmospheric transport

Root uptake/contact

Wet/dry deposition

Ingestion Leaching to Groundwater Irrigation

water

Dotted lines indicate exposure pathways that have a low likelihood of contributing to ecological risk.

The conceptual model for potential risks of pyrethrins to aquatic organisms due to various indoor uses of the chemical that could potentially end up in a “drain” and disposed through domestic wastewater is depicted in Fig. 6.2 . The stressor is the chemical of concern, pyrethrins. It is noted that the transport pathway is wastewater fl ow, the exposure media is the treatment facility and the exposure route, receptor, and attribute changes for aquatic organisms are similar to the conceptual model for agricultural applications.

EFED performed a preliminary assessment of the “down-the-drain” uses and found that RQs did not exceed any LOCs (see Appendix C ). The Division will perform a similar assessment, using refined usage information and new endpoints (i f any are developed, from newly submitted studies) in the Registration Revi ew ecological risk assessment.

50Figure 6.2. Conceptual model for potential ri sks of pyrethrins to aquatic organisms for
various indoor uses of the chemical that could potentially end up in the “drain”

Stressor Pyrethrins applications that could potentially end up “down-the-drain”

Source/ Transport Pathways Domestic wastewater flow; Partitioning with sewage sludge

Source/ Exposure
Media Treatment facility discharges into surface

waters

Exposure

Route Gill/ Integument Uptake

Receptors

Attribute Changes Aquatic Invertebrates,
Vertebrates

Individual
Vertebrates and

Invertebrates
Reduced survival or reproduction A quatic
Plants Uptake/ Adsorption

Plant Population
Reduced population

growth

The conceptual model for potential risks of pyrethrins to terrestrial and aqua tic organisms as a
result of the treatment on cattl e or calves is depicted in Fig. 6.3 . The stressor is the chemical of concern, pyrethrins, and potentially interactions caused by applications with the synergists PBO and MGK. The organisms that could be expected to be affected are terre strial plants, aquatic plants and aquatic animals. It is noted that the potential tran sport pathway, the exposure media and the exposure point or route, receptor, and attribute changes for plant and aquatic organisms are similar to the conceptual mode l for agricultural applications Fig. 6.1a

.

51Figure 6.3: Conceptual model for potential ri sks of pyrethrins to aquatic organisms as a
result of the treatment on cattle or calves.

Stressor Pyrethrins and PBO used as for the treatment of cattle and other animals (Immersion in surface water body or washoff transported nearby or to surface waters)

Source/ Transport Pathways Surface waters

Source/ Exposure
Media Riparian/
Wetland Foliage/Soil Receiving Water Body/
Sediment

Exposure
Route Direct Contact/ Root Uptake Gill/ Integument

Uptake

Receptors

Attribute Changes Aquatic Invertebrates,

Vertebrates Wetland/ Riparian

Plants

Individual Plants Reduced survival, growth, or reproduction Individual
Vertebrates and
Invertebrates
Reduced survival or reproduction Plant Population
Reduced population

growth Aquatic
Plants Uptake/ Adsorption

7. Analysis Plan

In order to address the risk hypot hesis, the potential for adverse effects on the environment is estimated. Usage, environmental fate and tran sport, and ecological e ffects of pyrethrins are characterized and integrated to assess the risks. This is accomplished using a risk quotient (ratio of exposure concentration to eff ects concentration) approach. A lthough risk is often defined as the likelihood and magnitude of adverse ecological effects, the risk quotient-based approach does not provide a quantitative estima te of likelihood and/ or magnitude of an adverse effect. However, as outlined in the Overview Docume nt (USEPA 2004), the likelihood of effects to individual organisms from par ticular uses of a chemical is estimated using the probit doseresponse slope and either the level of concern (d iscussed below) or the actual calculated risk quotient value.

This analysis plan will be re visited and may be revised dependi ng on the data available in the open literature and the information submitted by th e public or the registrant in response to the

52opening of the Registration Review docket.

7.1. Stressors of Concern

The focus of this assessment is on the parent material, pyrethrins. However, the Agency will review open literature to identify degradat e(s) of potential toxicological concern ( e.g. chrysanthemic acid, pyrethric acid, chrysanthemum dicarboxilic aci d, pyrethrolone, cinerolone and jasmolone). Also, risk resulting from use of pyrethrins and synergists will be assessed for
cattle treatments.

Toxicity data for environmental mixtures of pyr ethrins with other pesticides (those mixtures occurring in the environment following application), if available, may be presented as part of the ecological risk assessment. Pyre thrins may be applied in tank mixtures with other products approved for use on registered crops . It is expected that the t oxic effect of pyrethrins, in combination with other pesticides used in the en vironment, is likely to be a function of many factors including, but not necessa rily limited to (1) the exposed species, (2) the co-contaminants in the mixture, (3) the ratio of pyrethrins and co-contaminant concentrations, (4) differences in the pattern and duration of exposure among contamin ants, and (5) the differential effects of other physical/ chemical characteristic s of the receiving waters ( e.g. organic matter present in sediment and suspended water). A discussion of implicat ions of the available pesticide mixture effects
data on the confidence of risk asse ssment conclusions will be addre ssed in the risk description of the final ecological assessment.

7.2. Measures of Exposure

In order to estimate risks of pyrethrins exposures in aquatic and terres trial environments, all exposure modeling and resulting risk conclusion s will be made based on maximum application rates for the current use patterns. Available monitoring data will also be considered when describing potential environmental exposure to non-target organisms.

Measures of exposure are based on aquatic and terrestrial models that predict estimated environmental concentrations of pyrethrins using maximum labeled application rates and methods, as well as any mitigation measures specifically indicated on the label.

Additional information on the terrestrial exposur e models and screening tools employed in EPA ecological risk assessments for pesticides can be found at http://www.epa.gov/oppefed1/models/terrestrial/

.

More information on aquatic pestic ide exposure models can be found at http://www.epa.gov/oppefed1/models/water/index.htm

.

Dietary exposure to terrestrial organisms

Measures of exposure for terrestrial mammals , birds, reptiles and amphibians similarly incorporate maximum proposed use rates but rely less on fate properties. Terrestrial exposures were estimated using a number of methods. For pyrethrins, acute and chronic terrestrial

53exposure estimates are derived directly from em pirically determined observations of pesticide
residues on various terrestrial food items. Th e Kenaga nomogram, as modified by Fletcher et al

, (Kenaga and Hoerger, 1972; Fletcher et al , 1994) is used to relate pe sticide application rates to residues on terrestrial food items. The surface residue concentration (ppm) is estimated by multiplying the application rate ( pounds active ingredient per acre) by a value specific to eachfood item. For numerous applications for a given use, the exposure model incorporates a firstorder decay rate dependent on the foliar dissipation half-life of th e chemical. In the absence of foliar dissipation data, a default foliar diss ipation half-life of 35 days is used.

Inhalation, drinking water and dermal exposure

Two screening tools were utilized to assess the potential for pyr ethrins exposure to terrestrial organisms via inhalation and drinking water exposure. The S creening T ool for I nhalation R isk (STIR v.1.0, November 19, 2010) was used to cal culate an upper bound estimate of exposure using vapor pressure and molecula r weight of pyrethrins for vapor phase exposure, as well as the maximum application rate and method of applicati on for spray drift. STIR incorporates results from several toxicity studies including acute oral and inhalation rat toxicity (oral LD 50 = 1400 mg/kg bw and LC 50 >3.4 mg/L, respectively) as well as the most sensitive acute oral avian toxicity endpoint (bobwhite quail, LD 50 > 2000 mg ai/kg bw). Based on the results of the STIR model, inhalation exposure alone was determined not to be a potential pathway of concern for avian and mammalian species on an acute basis.

Inhalation exposure via spray drift and vapor-phase of the pyrethrins alone does not appear to be of concern. The analysis of the inhalation route of in STIR does not consider that aggregation with other exposure pathways such as dietary, de rmal, or drinking water may contribute to a total exposure that has a potential fo r effects to non-target animals. However, the Agency does consider the relative importance of other routes of exposure in situ ations where data indicate that pesticide exposures through other routes may be potentially signi ficant contributo rs to wildlife risk (US EPA, 2004).

The S creening I mbibition P rogram (SIP v.1.0, Released June 15, 2010) was used to calculate an upper bound estimate of exposure using pyrethrin’s so lubility (9 mg/L), the most sensitive acute avian oral toxicity endpoint (bobwhite quail, LD 50 > 2000 mg ai/kg bw) and the most sensitive
acute and chronic mammalian toxicity endpoints (oral LD 50 = 1400 mg/kg bw and NOAEL = 6.4 mg/kg bw, respectively). Drinki ng water exposure alone was determined not to be a potential pathway of concern for avian and mammalian sp ecies on an acute basis or for mammalian species on a chronic basis. However, chronic av ian data was not available to include in the preliminary drinking water screen.

Although drinking water exposure alone does not appear to be of concern, this does not take into account that when aggregated with other exposure pathways (dietary food sources, dermal, inhalation) drinking water may c ontribute to a total exposure that has a potential for effects on non-target animals and should be explored fu rther. Because there is a high degree of
conservatism in the SIP 1.0 exposure estimate, there is limited expectation that use scenarios not triggering a SIP 1.0 concern would contribute significantly to a ggregate risks from water plus diet when a refined water exposure model is in corporated in the actual quantitative risk

54assessment.

Although not available at this time, the Agency is actively pursuing modeling techniques to account for dermal exposure via direct applica tion of spray and by inci dental contact with contaminated vegetation, soil and water.

Exposure to terrestrial plants

TerrPlant is used by the Environm ental Fate and Effects Division (EFED) as a Tier 1 model for screening level assessments of pesticides. The pur pose of TerrPlant is to provide screening level estimates of exposure to terrestrial plants from single pesticide a pplications. The model does not consider exposures to plants from multiple pesticide applications. TerrPlant derives pesticide EECs in runoff and in drift. RQs are developed for non-listed and listed species of monocots and dicots inhabiting dry and semi-aqua tic areas which are adjacent to treatment sites. Once suitable terrestrial plant data are submitted to the Agen cy, this model will be used to determine the potential risks to terrestrial plants following pyrethrins applications.

Aquatic exposure modeling

The models used to predict aquatic EECs are th e Pesticide Root Zone Model coupled with the Exposure Analysis Model System (PRZM/EXAMS). Also, to estimate aquatic exposure related to releases of pyrethrins from domestic wast ewater treatment plants, the Exposure and Fate Assessment Screening Tool’s (E-FAST2) down- the-drain module will be used. For the treatment of cattle, measures of exposure will be calculations assuming di rect applications to water considering living habits of cattle livestock.

PRZM (v.3.12.2, May 2005) and EXAMS (v.2.98.4.6, April 2005) are simulation models coupled with the input shell PE5.pl (August, 2007) to generate daily exposures and 1-in-10 year EECs of pyrethrins, that may occur from spray drift and runoff to surf ace water bodies adjacent to application sites. PRZM simulates pestic ide application, movement and transformation on an agricultural field and the result ant pesticide loadings to a receiving water body via runoff, erosion and spray drift. The EXAMS model simu lates the fate of the pesticide and resulting concentrations in the water body. The standa rd scenario used fo r ecological pesticide assessments assumes application to a 10-hectare ag ricultural field that drains into an adjacent 1- hectare water body that is 2 meters deep (20,000 cubic meters volume) with no outlet. PRZM/ EXAMS is used to estimate screening-level exposu re of aquatic organisms to pyrethrins and/ or its transformation products, should they be of concern. The measure of exposure for aquatic species is the 1-in-10 year return peak or rolling mean concentra tion. The 1-in-10 year peak is used for estimating acute exposures of direct eff ects to aquatic organisms. The 1-in-10-year 60- day mean is used for assessing chronic exposure to fish and aquatic-phase amphibians. The 1-in10-year 21-day mean is used for assessi ng aquatic invertebrate chronic exposure.

At the present time, EFED considers the use of the impervious scenar io (a PRZM modeling scenario) as the most suitable available modeling approach for simulating runoff from impervious surfaces such as roads, sidewalks, patios and parking lots. The PRZM impervious scenario may be used in the tier 2 coupl ed aquatic models PRZM/EXAMS along with the

55residential or other suitable scenario such as rights-of-way (ROW) to obtain EECs. The conceptual model for the resident ial scenario integrates simulta neous modeling of the individual use scenario with an impervious scenario. This approach assumes that no watershed is completely covered by either the 1⁄4 acre lot (the basis for the residential scenario) or undeveloped land (the basis for the ROW scenar io) for residential and ROW use patterns; therefore, differential amounts of runoff will oc cur within the watershed. The impervious scenario was developed to repr esent the paved areas within a watershed not including roads, parking lots, sidewalks, and build ings outside the 1⁄4 acre lot (the 1⁄4 acre lot scenario accounts for impervious surfaces such as buildings within th e represented area). By modeling a separate scenario for impervious surfaces, it is also pos sible to estimate that amount of exposure that could occur when the pesticide is oversprayed onto this surface. Using two scenarios in tandem requires post-processing of the modeled output in order to derive a weighted EEC that represents the contribution of both the pervious ( i.e. , residential and ROW scenarios) and the impervious
surfaces.

In general, incorporation of impervious surf aces into the exposure assessment results in increasing runoff volume in the watershed, which te nds to reduce overall pesticide exposure. For the purposes of risk assessment alternate assumptions for percent impervious surfaces, percentage of use site treated, and percentage of overspray may be considered in order to characterize the assumptions of the ecological risks assessment in the context of the individual exposure assessment and risk conclusions. For exam ple, previously tested assumptions used in the endangered species assessments may be considered for characterization ( i.e. , 10% and 30% impervious surfaces, 10% lot treated, and 0%, 1% and 10% overspray) unless other relevant values can be determined ( i.e. , modeling may be completed for the impervious surface with 0%, 1% and 10% overspray to provide lower and upper bound values). Th e results of these alternate modeling exercises may be discussed in the assessment.

Given the aquatic toxicity of pyrethrins and its likelihood to occur in sediment, the Agency will also consider the potential expos ures resulting from be nthic/ sediment concentrations (EECs). Pore water concentrations are commonly used to predict toxicity of non-ionic substances in sediments and characterize exposure to organisms th at spend time in or near sediments (Di Toro
et al. 1991; US EPA 2002). PRZM/ EXAMS estimat es 1-in-10-year peak and 21-day mean EECs for pore water.

To estimate exposure related to releases of pyr ethrins from domestic wastewater treatment plants, the Agency will rely on the Office of Pollution Prevention and Toxics (OPPT) model, Exposure and Fate Assessment Screening Tool (EFAST, version 2.0, or EFAST2, 2007). From this model, the Agency will use the “Down-the-Dr ain” module, which is designed for releases to
domestic wastewater treatment. It is suitabl e for all the sources of pyrethrins that could potentially be exposed through a “down-the-drain” scenario ( i.e. , disposed through domestic wastewaters). The model provide s screening level estimate con centrations of chemicals in surface water that may result from household uses and the disposal of consumer products into wastewater using a few simple input parameters (production volum e and fraction of the chemical removed during wastewater treatment). The Agency has conducted a preliminary analysis of the exposure resulting from wastewater effluents from POTWs and compared against the available acute and chronic endpoints for pyrethrins and has found no RQs exceeded any of the LOCs. At

56the present time, the Agency does not anticipate to require of a POTW treatability study. EFED anticipates repeating the analysis for the fina l ecological risk assessment using more refined production volume values provided by BEAD or th e registrant and any new endpoints (if any), developed during Registration Review.

Since pyrethrin has uses on rice, the screening-le vel Tier 1 Rice Model v.1.0 will be utilized to obtain estimated exposure concentrations (EECs) re lated to that use. The Tier I Rice Model v1.0 relies on an equilibrium partitioning concept to pr ovide conservative estimates of environmental concentrations resulting from a pplication of pesticides to rice paddies. When a pesticide is applied to a rice paddy, the model assumes that it will instantaneously partition between a water phase and a sediment phase. Among the assumpti ons of this model, the degradation of the pesticide and the mass transfer from the aqueous phase to the sediment ar e not considered. Also,
volatilization and other dissi pation processes are not considered. If LOCs are exceeded using the Tier 1 rice model, estimates may be made using a provisional model, PFAM to better characterize the risk. However, PFAM is not yet approved for general use for calculating pesticide EECs by the Agency.

There are two possible scenarios whereby pyrethr ins residues can enter the aquatic ecosystem due to treatment to cattle. First, multiple cattle that are treated with pyret hrins can directly enter a water body, and second, rainfall can cause was hoff of pyrethrins residues to be transported from treated multiple cattle to water bodies via runoff. For these cases, surface water concentrations will be calculated using the maxi mum mass of pyrethrins per animal, spilling into a standard farm pond of 1 ha area an d 2 m depth or a volume of 2.0 x 10 7 L. Surface water EECs will be calculated utilizing a suitable program wh ich considers the soil-water partition coefficient and the depth of the sediment layer such as the KdCalc (v.1.0 10/02/02) . Certain assumptions are required for these scenarios. For example, for the first scenario, 20 treated cattle may be
assumed to enter the water and for the second sc enario, a 1000 treated ca ttle feedlots may be assumed (USDA NASS data). 5 A maximum of 100% of the ac tive ingredient is assumed to wash-off cow hide for pour on products.

Bioaccumulation

The potential for bioaccumulation for the chemical is assessed using the KABAM model, as well
the results from bioconcentr ation in fish studies ( e.g. the bioconcentration factors). These models are parameterized using relevant reviewed registrant-submitted environmental fate and transport data.

As indicated in Table 3.1 and its associated text in Section 3 , pyrethrins appears to have some potential to bioconcentrate in aqua tic organisms and it appears that th ere is also some potential to biomagnify in terrestrial organisms. The potenti al for bioaccumulation of pyrethrins will also be examined in the risk assessment. Because pyrethrins have a fairly high K OW (2.0 x 10 4 – 7.9 x
10 5 ) and the chemical may be persistent in water (despite having a short aqueous photolysis halflife, it could be persistent to hydrolysis at pH 7) and sediments (>10 days of aquatic metabolism), there could be a potential for bioaccumulation. The ma ximum bioconcentration

5 http://www.nass.usda.gov/Surveys/Guide_to _NASS_Surveys/Cattle_On_Feed/index.asp (accessed 02/01/11) “Feedlots with 1,000 or more head capacity represen t about 85 percent of all fed cattle in the U.S.”

57factor was 471x for whole fish; however, the depurat ion rate is rapid (half depuration time of <1 day, MRID Nos. 43302301 & 43884102). Bioaccumulation will be assessed using the results
from bioaccumulation in fish studi es, as well as the KABAM model (K OW (based) Aquatic BioAccumulation Model, version 1.0, 2009), adjusti ng for biotransformation rates. KABAM is used to estimate potential bioaccumulation of hydrophobic organic pesticides in freshwater aquatic ecosystems and risks to mammals and bi rds consuming aquatic organisms which have bioaccumulated these pesticides. Monitoring data and biotransformation rates in terrestrial species will also be evaluated, to assess the po tential for bioaccumulatio n in terrestrial food
webs.

7.3. Measures of Effect

Ecological effects data are used as measures of di rect and indirect effects to biological receptors. Data are typically obtained from registrant-submitte d studies or from literature studies identified by ECOTOX. The ECOTOX database provides more ecological effects data in an attempt to bridge existing data gaps. EC OTOX is a source for locating singl e chemical toxicity data and potential chemical mixture toxicity data for aq uatic life, terrestrial plants, and wildlife. ECOTOX was created and is maintained by the US EPA, Office of Research and Development,
and the National Health and Environmental Ef fects Research Laboratory's Mid-Continent Ecology Division.

The acute measures of effect used fo r animals in this assessment are the LD 50 , LC 50 and EC 50

. LD stands for "Lethal Dose", and LD 50 is the amount of a material, given all at once, that is
estimated to cause the death of 50% of the test organisms. LC st ands for “Lethal Concentration”
and LC 50 is the concentration of a chemical that is estimated to kill 50% of the test organisms.
EC stands for “Effective Concentration” and the EC 50 is the concentration of a chemical that is estimated to produce a specific effect in 50% of the test organisms. Endpoints for chronic measures of exposure for listed and non-lis ted animals are the NOAEL/NOAEC and NOEC.
NOAEL stands for “No Observed-Adverse-Effect-Level ” and refers to the hi ghest tested dose of a substance that has been reported to have no harm ful (adverse) effects on test organisms. The NOAEC ( i.e. , “No-Observed-Adverse-Effect-Concentration” ) is the highest test concentration at
which none of the observed effects were statisti cally different from the control. For non-listed plants, only acute e xposures are assessed ( i.e. , EC 25 for terrestrial plants and EC 50 for aquatic plants); for listed plants either the NOAEC or EC 05 is used.

At the time of the risk assessment, updated info rmation on the potential effects of pyrethrins on non-target animals will also collected from the Ecological Incident Information System (EIIS), Aggregrate Incident Reports and the Avian Monitoring Information System (AIMS).

Where available, sub-lethal effects observed in both registrant-submitted and open literature studies will be evaluated qualitatively. Such effects may include behavioral changes ( e.g. , lethargy and changes in colora tion). Quantitative assessments of risks, though, are limited to those endpoints that can be di rectly linked to the Agency’s assessment endpoints of impaired survival, growth and reproduction.

The assessment of risk for direct effects to non- target organisms makes the assumption that the

58toxicity of pyrethrins to birds is similar to terrestrial-phase am phibians and reptiles. The same assumption is made for fish a nd aquatic-phase amphibians.

7.4. Integration of Exposure and Effects

Risk characterization is the integration of e xposure and ecological effects to determine the potential ecological risk from the use of pestic ides and the likelihood of direct and indirect effects to non-target organisms in aquatic and te rrestrial habitats. The exposure and toxicity effects data are integrated in order to evaluate the risks of adverse ecological effects on nontarget species. For the assessment of risks, the risk quotient (RQ) method is used to compare exposure and measured toxicity va lues. 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). These criteria will be used to indicate when pyrethrins uses, as dire cted on the label, have the potential to cause adverse direct or indirect effects to non-target organisms. In addition,
incident data from the EIIS will be consider ed as part of the risk characterization.

7.5. Deterministic and Probabilistic Assessment Methods

The quantitative assessment of risk will primarily depend on the deterministic point-estimate based approach described in the risk assessment. An effort may also be made to further qualitatively describe risk using probabilistic to ols that the Agency has developed. These tools have been reviewed by FIFRA Scientific Advisory Panels ( http://www.epa.gov/sc ipoly/sap/index.htm ) and have been deemed as appropriate means of refining assessments where deterministic approaches have identified risks.

7.6. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to Federally-listed th reatened and/or endangere d (listed) species from registered uses of pyrethrins. This assessm ent will be conducted in accordance with the Overview Document (USEPA 2004), provisi ons of the ESA, and the Services’ Endangered Species Consultation Handbook (USFWS/NMFS, 1998).

The assessment of effects associat ed with the registration of py rethrins is based on an action
area. The action area is considered to be the ar ea directly or indirectly affected by the federal action, as indicated by the exceedance of Agency Le vels of Concern (LOCs) used to evaluate
direct or indirect eff ects. The Agency’s approach to defi ning the action area under the provisions of the Overview Document (USEPA 2004) considers the results of the risk assessment process to establish boundaries for that action area with the understandi ng that exposures below the Agency’s defined LOCs constitute a no-effect threshold. For th e purposes of this assessment,
attention will be focused on the footprint of the action ( i.e. , the area where pyret hrins application occurs), plus all areas where offsite transport may result in potential exposure that exceeds the Agency’s LOCs. Specific measures of ecologica l effect that define the action area for listed species include any direct and indirect effects and/ or potential modification of its critical habitat, including reduction in survival, growth, and reproduction as well as the full suite of sub-lethal
effects available in the effects literature. Ther efore, the action area extends to a point where

59environmental exposures are below any measured lethal or sub-le thal effect threshold for any biological entity at the whole organism, organ, tissu e, and/ or cellular level of organization. In situations where it is not possible to determin e the threshold for an observed effect, the action area is not spatially limited and is assumed to be the entire United States.

7.7. Drinking Water Assessment

A drinking water assessment will be conducted to support future human health risk assessments of pyrethrins should it be required, based on all the available environmental fate information. The drinking water assessment will incorporate model estimates of pyrethrins in surface and ground waters. Concentrations in surface waters will be estimated using FQPA Index Reservoir Screening Tool (FIRST, v.1.1.1, 12/18/07) (or subs equently using PRZM/ EXAMS, with the Index Reservoir – for description see above – if refinements are required). Ground water
estimates of concentrations will be obtained using the Screening Concentration In GRound Water (SCI-GROW) model (v.2.3, July 2003). The drinking water assessment will also include a summary of available surface a nd ground water monitoring data.

7.8. Endocrine Disruptor Screening Program

As required by FIFRA and the Federal Food, Dr ug, and Cosmetic Act (FFDCA), EPA reviews numerous studies to assess pot ential adverse outcomes from exposure to chemicals. Collectively, these studies include acute, subchr onic and chronic toxicity , including assessments of carcinogenicity, neurotoxicity, developmental, reproductive, and general or systemic toxicity. These studies include endpoints which may be susceptible to endocrine influence

, including effects on endocrine target or gan histopathology, organ weights, estrous cyclicity, sexual maturation, fertility, pregnancy rates, reproductiv e loss, and sex ratios in offspring. For ecological hazard assessments, EP A evaluates acute tests and chr onic studies that assess growth, developmental and reproductive effects in di fferent taxonomic groups. As part of its reregistration decision

, EPA reviewed these data and selected the most sensitive endpoints for
relevant risk assessment scenarios from the exis ting hazard database. However, as required by FFDCA section 408(p), pyrethrins ar e subject to the endocrine scre ening part of the Endocrine Disruptor Screening Program (EDSP).

EPA has developed the EDSP to determine whet her certain substances (including pesticide active and other ingredients) may have an effect in humans or wildlife similar to an effect produced by a “naturally occurring estrogen, or ot her such endocrine effect s as the Administrator may designate.” The EDSP employs a two-tiered approach to making th e statutorily required
determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a chemical substance to interact with the estrog en, androgen, or thyroid (E, A, or T) hormonal systems. Chemicals that go th rough Tier 1 screening and are found to have the potential to interact with E, A, or T hormonal systems will proceed to the next stag e of the EDSP where EPA will determine which, if any, of th e Tier 2 tests are necessary base d on the available data. Tier 2 testing is designed to identify a ny adverse endocrine-related eff ects caused by the substance, and establish a dose-response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must scre en all pesticide chemicals. Accordingly, as

60part of registration review, EP A will issue future EDSP orders /data call-ins, requiring the submission of EDSP screening assays for pyrethrins. For further information on the status of the EDSP, the policies and procedures, the current and future chemical lists, the test guidelines and the Tier 1 screening battery, please visit our website: http://www.epa.gov/endo/

.

7.9. Preliminary Identification of Data Gaps

7.9.1. Environmental Fate Data Gaps

After evaluation of the available data for pyret hrins, the following data gaps for registration
review have been identified.

835.4100 Aerobic Soil Metabolism - There is an aerobic soil metabolism study, conducted on a single soil system. Aerobic soil metabolism studies with one soil type are generally sufficient for the evaluation of transformation pathways. Rates of transformation should be determined in at least three additional soils (from Fate, Trans port and Transformation Test Guidelines – OCSPP Guideline 835.4100 & 835.4200). Thus, aerobic soil metabolism studies are required to be
conducted in three additional di fferent soils. For metabolism studies, domestic soils are preferred.

835.4200 Anaerobic Soil Metabolism – There is no available study. Anaerobic studies with one soil type are generally sufficient for the ev aluation of transformation pathways. Rates of
transformation should be determined in at least three additional soils (from Fate, Transport and Transformation Test Guidelines – OCSPP Guideline 835.4100 & 835.4200). The registrant is required to perform an anaerobic soil metabolism study, conducted in four different soils. For metabolism studies, domesti c soils are preferred.

835.4300 Aerobic Aquatic Metabolism – A study is available, wh ich was conducted in a single soil/ sediment system. According to the OC SPP Fate, Transport and Transformation Test Guidelines (835.4300 & 835.4400) “At least two sediment s and their associated waters are used
for both the aerobic and the anaerobi c studies respectively.” It furt her says that, “However, there may be cases where more than two aquatic se diments should be used, for example, for a chemical that may be present in freshwater an d/or marine environments. Sediments should be representative of intended us e sites.” Since pyrethrins have a high potential for use near estuarine/ marine areas, one of the required sediment systems should be from estuarine/marine environment. Therefore, two additional differe nt sediment systems are required for pyrethrins, one of which should be of marine origin. Fo r the metabolism studies, domestic sediments are preferred.

835.4400 Anaerobic Aquatic Metabolism – A study is available in one soil/sediment system. According to the OCSPP Fate, Transport a nd Transformation Test Guidelines (835.4300 & 835.4400) “At least two sediments and their associated waters are used for both the aerobic and the anaerobic studies respectively... However, ther e may be cases where more than two aquatic sediments should be used, for example, for a chemical that may be present in freshwater and/or marine environments. Sediments should be represen tative of intended use sites.” At this time, EFED is requiring anaerobic aqua tic metabolism studies conducte d with two water/ sediment

61systems. Since pyrethrins have a high potential for use near estuar ine/ marine areas, one of the required sediment systems should be from estuar ine/ marine origin. For all the metabolism studies, domestic sediments are preferred.

EFED recommended to waive the Terrestrial and Aquatic Field Dissipation ( OCSPP
835.6100 and 835.6200 ) data requirements. EFED believes that a new study will not substantially change the environm ental fate assessment. The pa rent degrades rapidly and the ultimate degradate is CO 2 , and bound residues in soil. It appe ars that metabolites produced are of no significant environmental concern, as indica ted earlier. The proposed use rate is low (single application rate of 0.050 lb a.i./acre, season al application rate of 0.50 lbs a.i./acre). The degradates such as chrysanthemic acid may not reach sufficiently high levels to pose a toxicological concern. Based on data from the labor atory studies, at the cu rrent application rate, in field use conditions the peak degradates’ c oncentrations are likely to be below 0.01 ppm.

Other studies:

Environmental Chemistry Methods (ECMs), and Independent Laboratory Validations (ILVs), for Soil, Water and Sediment . ECMs associated with the Terrestrial Field Dissipation study (Field dissipation §158.1300; O PPTS guidelines 835.6100, 835.6200, and 835.6300), along with successful confirmatory method trials (validation) by an independent laboratory ( i.e. ILVs), are required. If there is risk concern for a given taxon, ECMs should be available for the environmental media in which organisms of the taxon reside. These ECMs should have limits of quantification for the residues of c oncern that are lower than the re levant toxicological levels of concern. Previous reviews on pyrethrins indicate that there is high concer n for acute and chronic toxicity to aquatic animals, in cluding those living in the benthos. Certain scenarios triggered
acute and chronic levels of con cern for freshwater and/or estuar ine/marine aquatic invertebrates and/or for fish and/or organisms living in the benthos. Therefore, ECMs for water and sediment are required in addition to the ECM for soil. The ECMs should include pa rent and those residues found in the laboratory studies that exceeded 10% of the applied. Based on the available data at this time, the following appear to be the resi dues of concern for each media, but this could change, based upon the results of newly submitte d environmental fate and ecological effects studies (if any is conduc ted on the degradates): Soil – parent compound Water and Sediment – parent, chrysanthemi c acid and chrysanthemum dicarboxylic acid The registrant is encouraged to submit state-of-the-art environm ental chemistry methods; further, multi-residue methods (MRMs) for soil, water and se diment are preferred, if applicable. There is one method for pyrethrins published in the Agency’s ECM website 6 for the analysis of total pyrethrins in water only (MRID N o. 43884102). The Agency will veri fy the suitability of this method and the appropriateness of its levels of quantitation (0.06 μg/L or ppb). At this time, no specific methods have been identified for the anal ysis of degradates of the pyrethrins. A full description of the method valida tion procedures performed by an independent laboratory should also be submitted. It should include the following information (Corbin et al. 2006): (a) Recovery level(s) of the test compound(s) from the soil, water and sediment (substrates) at various relevant fortification level(s) us ing the residue analytical methodology; (b) a validated method sensitivity level; (c) results of the study and statistical test applied, including a step wise presentation of the

6 Available at url: http://www.epa.gov/pesticides/methods/ecmindex.htm

62procedure for calculating percent recovery from the raw data; (d) all the data/ information necessary to independently verify the results; (e) summary of th e results; and, (f) discussion and
conclusions of the results.

EFED Does Not Recommend Requesting a PO TW Treatability Study at This Time – The Agency has recently requested and provided comments on a protocol developed by the Pyrethroid Working Group (PWG) for a bench scale study of wastewater treatment for pyrethroids, to assess the percen tage removed in the biosolids by the treatment, the amount that would degrade during treatment, and the amount th at would remain in the wastewater. These data have been required for several synthetic pyrethroid compounds to inform removal percentages by waste water treatment, which is an input to the Exposur e and Fate Assessment Screening Tool’s (E-FAST) “Down-the-Drain” module. Based upon (a) a preliminary risk assessment performed using the “Down-the Drai n” module which does not account for possible degradation of the chemical in wastewaters or pa rtitioning with organic matter/ particulate matter in wastewaters, (b) a highly conservative pr oduction volume estimated value (that assumed all consumer indoor plus Pest Control Operator (PCO) volume goes ‘down-the-drain’), (c) default wastewater treatment half-lives of 10,000 hr (~ 417 days) in the primar y, aeration and settling
tanks instead of the EPISuite v.4.0 estimated half -lives range of 30-300 hrs or ~1-12 days), and (d) the most conservative stream dilution factor of 1.00 ( i.e. , no dilution) that results from the high end 10 th percentile concentration), all of the aquatic RQs were below the acute or chronic LOCs. Based on the best available information, at the present time, it is anticipated that this study will not be required for pyrethrins (f or modeling output files, refer to the Appendix C ).

The Agency is actively evaluating the extent to which ecological risk from pesticide active ingredients, such as pyrethrins, via land application of biosol ids should be addressed in its forthcoming environmental fate and ecological risk assessment and by extension, any additional data that may be required. As part of this evaluation, OPP is working closely with the Office of Water which regulates land application of biosolids under the Clean Water Act.

EFED is aware of a study that suggests inhi bition of POTW treatment processes is not a significant risk due to pyrethrin exposures. A study was submitted to the EU and reported in the Draft Assessment Report (DAR) for Pyrethrins (Koopmans 1995). EFED believes that the submission of the study to the Agency fo r further evaluation will be beneficial.

Table 7.1 lists the status of the environmental fate data requirements for pyrethrins.

63Table 7.1. Summary of Environmental Fa te Data Requirements for Pyrethrins

Study Identification Use
Pattern 1 Does EPA Have Data To Satisfy This Requirement? Bibliographic Citation Must Additional
Data Be Submitted
Under FIFRA

3(c)(2)(B)?

§158.1300 ENVIRONMENTAL FATE
Degradation Studies-Lab : 835.2120 Hydrolysis 1,2,3 Yes 43188201, 43567502 No 835.2240 Photodegradation in
Water 1,2,3 Yes 43096601, 43567601 No

835.2410 Photodegradation on
Soil 1,2,3 Yes 43096602 No

835.2370 Photodegradation in
Air 1,2,3 No Not Available No 2

Metabolism Studies-Lab :

835.4100 Aerobic Soil 1,2,3 Yes 43499803 Yes 3

835.4200 Anaerobic Soil 1,2,3 No Not Available Yes 3

835.4300 Aerobic Aquatic 1,2,3 Yes 43499802 Yes 4

835.4400 Anaerobic Aquatic 1,2,3 Yes 43499801 Yes 4

Mobility Studies : 835.1230 Leaching – Adsorption/ Desorption 1,2,3 Yes 43096603 No

835.1410 Volatility (Lab) 1,2,3 Yes 43096604 No
835.8100 Volatility (Field) 1,2,3 No Not Available No 2

Dissipation Studies-Field :

835.6100 Terrestrial Field Dissipation 1,2,3 Yes 42745501 No 5

835.6200 Aquatic Field Dissipation 1,2,3 Yes 43818501 No 5

835.6300 Forestry Dissipation 1,2,3 No Not Applicable N/A Ground Water Monitoring Studies :

835.7100 Ground Water Monitoring 1,2,3 No Not Available No 6

§158.1100 SPRAY DRIFT

201-1 Droplet Size Spectrum 1,2,3 No Not Available No 7

202-1 Drift Field Evaluation 1,2,3 No Not Available No 7

Other Studies : Environmental Chemistry Methods (ECMs) and Independent Laboratory Validations (ILVs) 1,2,3 Yes 43884102 Yes 8

POTW Treatability Study Indoor Uses No Not Available No 9

64Table 7.1. Summary of Environmental Fa te Data Requirements for Pyrethrins

Must Additional
Data Be Submitted Does EPA Have

Study Identification Use Under FIFRA Data To Satisfy Pattern 1 Bibliographic Citation 3(c)(2)(B)? This Requirement? 1. Use Patterns: 1=Terrestrial/Food; 2=Te rrestrial/Feed; 3=Aquatic/Food or Non-Food. 2. EFED recommended a data waiver based on the relatively low vapor pressure and Henry’s Law Constant for pyrethrins, and low levels of pyrethrins evolved in an available labora tory volatility study (DP Barcode D300419). Furthermore, the predicted environmental half-life for the chemi cal is short (due to OH radical reaction). 3. The registrant conducted studies with only one soil system. According to current OCSPP guidelines, four soils are required. 4. Only one sediment system was evaluated while current gu idelines require at least two. A study, performed with two water/sediment systems is required, one of which should be of marine origin. 5. EFED recommended a data waiver based on the environmental fate characteristics of the pyrethrins and evaluation of the available terrestrial field dissipa tion study (DP Barcode D227214+). 6. With high K d and K OC values, and moderate half-life values, it appears unlikely that leaching will be important for these chemicals. EFED recommended a waiver of the study (DP Barcode D300419). 7. Data requirements covered by submission of the Spray Drift Task Force. 8. The data requirement remains unfulfilled for pyrethrins, pending evaluation of the available study. 9. Based upon a preliminary risk assessment performed using the E-FAST’s “Down-the Drain” module and a highly conservative production volume value, EFED belie ves that this study will not be required.

7.9.2 Effects

For registration review, the following studies are requested to fulfill any data gaps:

Guideline Number: 850.2100 Study Title: Avian acute oral t oxicity test (passerine species) Acute avian oral toxicity data are required for either one waterfowl or one upland game species and one passerine species under the Part 158 da ta requirements (CFR 40 2008) for conventional pesticides. Because passerine spec ies have higher metabolic rates due to their smaller sizes than either waterfowl or upland game bird species, a nd because they may utilize different metabolic pathways, they may be more or less sensitive to pyrethrins. A recent study reported that at least one passerine species (canary, Serinus sp ) is sensitive to a formulated pyrethroid, beta cyfluthrin,
with a calculated LD 50 of 170 mg/kg bw (Addy-Orduna et al 2011). The other two species tested in this study, shiny cowbird (Order Passerifo rmes) and eared doves (Order Columbiformes), showed decreased sensitivity to beta cyfluthrin (LD 50 of 2234 mg/kg bw and 2271 mg/kg bw, respectively). Based on a preliminar y screen using the highest agri cultural application scenario for pyrethrins (see Table 3.3 ), the highest peak dose-based EEC is 125 mg/kg bw. This level of acute exposure could be an environmentally-rele vant if pyrethrins show the same increase in toxicity to passerine species th at is indicated by the study with beta cyfluthrin. In order to properly characterize risk to passerines, an avian oral toxicity test is requested. A passerine study protocol must be submitted for review by the Agency prior to in itiation of the study.

Guideline Number: 850.2300 Study Title: Avian reproduction test No avian reproduction data have been submitted fo r pyrethrins. The Part 158 (CFR 40 2008) lists

65avian reproduction data as a requirement to support all outdoor products. Studies with pyrethroids have shown reproductive effects to avian species at low levels of exposure, including cyhalothrin (NOAEC = 5 mg/ kg diet; MRID 00153504) and permethrin (NOAEC = 125 mg/kg diet; MRID 42322902). In addition, chronic eff ects were observed in mammalian reproduction studies at exposure concentrati ons that exceeded levels-of-co ncern for pyrethrins (chronic RQ=1.10; US EPA 2006b). Tests are recommende d for the technical product with both waterfowl and an upland game bird species.

Guideline Number: 850.1350 Study Title: Aquatic Invert ebrate Life-Cycle (saltwater) Previously submitted studies indicate that estuarine/marine invertebrates are among the most sensitive taxa to pyrethrins on an acute basis, with effects expected below 2 μg a.i./L.

The need for a life cycle chronic toxicity of pyrethrins to estu arine/marine invertebrates is indicated based on its aquatic t oxicity and environmental fate properties according to 40 CFR Part 158 data requirements (October 26, 2007). Specifically:
1. Pyrethrins are intended for use such that its presence in estuarine/marine environment in significant c oncentrations is expected;
2. The acute LC/EC 50 for pyrethrins is substantiall y lower than the 40 Part 158 trigger value of 1 mg/L (1.4 μg a.i./L for pyrethrins and 0.14 μg a.i./L for pyrethrins + PBO product; Mysidopsis bahia ); and
3. Previous risk assessments have indicate d that the aquatic EEC s are > 0.01 of the
acute LC/EC 50 values for pyrethrins, which is another condition for triggering an estuarine/marine invertebrate life cycle study. In the most recent assessment for pyrethrins, the 21-day aquatic estimated exposure concentrations modeled for all 13 scenarios modeled crop scenarios range from 0.15 - 0.60 μg/L (US EPA 2006b).

Guideline Number: OCSPP 850.1760 (in pr ep), OCSPP 850.1770 (in prep.) and OCSPP 850.1780 (in prep.) Study Title: Whole sediment: chroni c invertebrates freshwater and marine
No chronic sediment toxicity tests for freshwater or marine invertebrates have been submitted for pyrethrins to satisfy th e Agency’s updated data requirement s for outdoor uses in 40 CFR Part 158 (October 26, 2007). For pyrethrins, available in formation indicates that benthic organisms may be exposed via run-off or spray drift applicati ons used in agricultural, forest, and residential settings. Based on calculations in the most recent EFED assessment, the 21-day sediment porewater EECs predicted for pyrethrins ranged from 0.03 to 0.20 μg a.i./L (USEPA 2008b). The upper end of this range exceeds 0.1 of the most sensitive acute LC/EC 50 (1.4 μg a.i./L for mysid shrimp), which satisfies one of the criteria for re quiring chronic whole sedi ment toxicity testing under 40 CFR Part 158. Furthermore, chronic reproduc tive effects were seen in water column studies with aquatic inverteb rates (daphnids), with a NOAEC = 0.86 μg a.i./L and LOAEC = 2.0 μg a.i./L.

Pyrethrins are expected to persist in sediments, based on half-lives in submitted soil metabolism and aquatic metabolism studies (a erobic soil = 9.5 days; aerobi c aquatic metabolism, 10.5 days; anaerobic aquatic metabolism, 86 days) (MRIDs 43499803, 43499802 and 43499801). These

66half-life values exceed the 40 CFR Part 158 criterion of 10 days.

The third set of trigger criteria for requiring chronic testing (K d > 50 or log K OW >3 or K OC > 1000) is also met for pyrethrins (log K OW is 4.5 to 5.9, the mean K OC value is ~35,200 assuming
it is similar to K FOC , and K d is 301.5 assuming it is similar to K F ). The physicochemical property triggers (K d , K OW and K OC ) reflect the propensity of the chemi cal to partition onto the particulate or organic matter phases of sediments. Ex ceeding any one of the physicochemical property triggers listed above is sufficient for indicating the pesticide has reasonable potential for partitioning to the sediment compartment.

Chronic whole sediment tests on Hyalella azteca

, Chironomus tentans , and Leptocheirus plumulosus are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche (epibenthic v. infauna l species), physiology, and there is some evidence suggesting Hyalella is among the more sensitive invertebrates to pyrethroids based on water column tests (Maund et al., 2002; Weston and Jackson, 2009). Pyrethrins have the potential to enter estuarine/marine water bodie s based on current usage patterns that include coastal areas. Therefore, test ing is also required for an es tuarine/marine sediment-dwelling invertebrate species.

Until the final OCSPP guidelines for chronic sediment toxicity tests are published, the registrant should submit a protocol to EFED for approval prior to test initiation.

• Test Method 100.4: Hyalella azteca 42-d Test for Measuring the Effects of Sediment
Associated Contaminants on Survival , Growth, and Reproduction in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated
Contaminants with Freshwater Invertebrates EPA 600/R-99/064 ( OCSPP 850.1770, in

prep. );

• Test Method 100.5: Life-cycle Test for Meas uring the Effects of Sediment-associated
Contaminants on Chironomus dilutus (formerly known as C. tentans ) in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated
Contaminants with Freshwater Invertebrates EPA 600/R-99/064 ( OCSPP 850.1760, in

prep. ); and

• Leptocheirus plumulosus in USEPA 2001 Method for Asse ssing the Chronic Toxicity of
Marine and Estuarine Sediment-associ ated Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R-01/020 ( OCSPP 850.1780, in prep. ).

Guideline Number: 850.1020 Study Title: Acute Freshwater Invertebrate Toxicity ( Hyalella azteca )

Acute water column tests with Hyallela azteca have been requested in pyrethroid problem formulations based on the increased sensitivity of this species to pyrethroid insecticides. The 850.1020 test guideline for Gammarid amphipod s is recommended with appropriate
modifications to address specific testing needs of H. azteca . The registrant should use OCSPP Guideline 850.1020 as a basis for developing the study, and submit a protocol prior to test initiation or submit any open literature studies that may fulfill this data gap.

67Guideline Numbers: 850.4150 and 850.4250 Study Title: Vegetative vigor a nd Seedling emergence, Tiers I/II No acceptable toxicity data are currently available to assess the risk of pyrethrins to non-target terrestrial plants. Since pyrethrins have many outdoor uses, vegetative vigor and seedling emergence studies are required. In addition, 5 major terrestrial plan t incidents have been reported to the Agency involving pyrethrins alone or pyr ethrins with piperonyl butoxide, a commonly used pyrethroid synergist. A total of 231 repor ted minor plant incident s are attributed to pyrethrins use. Phytotoxicity data are needed to assess the impact of pyrethrins on non-target terrestrial plants.

Guideline Number: 850.4400 and 850.5400 Study Title: Aquatic Plant Growth (al gal and aquatic vascular plant toxicity) Tiers I/II No acceptable toxicity data are currently available to assess the risk of pyrethrins to non-target aquatic nonvascular and vascular plants. Since pyrethrins have many outdoor uses, an aquatic plant growth toxicity study is requested with either pyrethrins technical or a typical end-use product.

The Agency is aware that additional pyrethrins data are available for the European Food Safety Authority reports (EFSA, 2008). It is recommende d that any applicable data generated for the European review process be submitted to EPA.

Table 7.2 lists the status of the ecological e ffects data requirements for pyrethrins.

Table 7.2. Ecological Effects Data Requirements for Pyrethrins.

Data Requirement Does EPA Have Data To Satisfy
This Requirement? Bibliographic Citation (MRID) Must Additional
Data Be Submitted Under FIFRA 3(c)(2)(B)?

§158.630 TERRESTRIA L ORGANISM TESTING

850.2100 Acute Avian Oral, Quail/Duck/Passerine Partially 42010901 Yes 1

850.2200 Acute Avian Diet, Quail Yes 41968801 No

850.2200 Acute Avian Diet, Duck Yes 41968802 No

850.2300 Avian Reproduction Quail No N/A Yes

850.2300 Avian Reproduction Duck No N/A Yes

§158.630 AQUATIC ORGANISM TESTING

850.1075 Acute Fish Toxicity Bluegill Yes 43082301 No

850.1075 Acute Fish Toxicity Rainbow

Trout Yes 43082303 No

850.1075 Acute Fish Toxicity (TEP) Yes 43082302, 43082304 No

850.1010 Acute Aquatic Invertebrate Yes 43082305 No

68Table 7.2. Ecological Effects Data Requirements for Pyrethrins.

Does EPA Have Must Additional Data To Satisfy

Data Requirement This Requirement? Bibliographic Data Be Submitted Citation (MRID) Under FIFRA 3(c)(2)(B)?

850.1010 Acute Aquatic Invertebrate (TEP) Yes 43082306 No

850.1075 Acute Est/Mar Toxicity Fish Yes 43082307 No

850.1075 Acute Est/Mar Toxicity Fish (TEP) Yes 43082308 No

850.1035 Acute Est/Mar Toxicity Shrimp Yes 43082311 No

850.1035 Acute Est/Mar Toxicity Shrimp (TEP) Yes 43082312 No

850.1025 Acute Est/Mar Toxicity Mollusk Yes 43082309 No

850.1025 Acute Est/Mar Toxicity Mollusk (TEP) Yes 43082310 No

850.1400 Early Life Stage Fish Yes 43252701 No

850.1300 Life Cycle Aquatic Invertebrate (freshwater) Yes 43252702 No

850.1350 Life Cycle Aquatic Invertebrate (saltwater) No N/A Yes

850.1500 Life Cycle Freshwater Fish No N/A No 2

850.1730 Bioaccumulation in Fish Yes 43302301, 43884102 No

OCSPP 850.1760 (in prep.), 850.1770 (in prep.) and 850.1780 (in prep.) Whole
sediment: chronic invertebrates
freshwater & marine No N/A Yes 3

850.1020 Aquatic Invertebrate Acute Toxicity ( Hyalella ) No NA Yes 4

§158.660 PLANT PROTECTION TESTING

850.4100 Seed Germ, Seedling Emergence No NA Yes 5

850.4150 Vegetative Vigor No NA Yes 6

850.4400, 850.5400 Aquatic Plant Growth No NA Yes 7

§158.490 INSECT POLLINATOR TESTING

850.3020 Honey Bee Acute Contact Yes 41968803 No

850.3030 Honey Bee Residue on Foliage No N/A No

850.3040 Field Test for Pollinators No N/A No

69N/A = Not applicable because no citation is available.

1 Data are required for a passerine species. The registrant must submit a protocol prior to conducting this study.

2 No additional data is required at this time. The results from the fish early-life stage studies will be used in the upcoming
risk assessment to evaluate the chronic risk of pyrethrins to fish species.

3 Until the final OCSPP guidelines for chronic sediment toxicity tests are published, the registrant should submit a protocol to EFED for approval prior to test initiation.

4 Acute water column tests with Hyallela azteca are requested for pyrethrins and pyre throids Registration Review ecological risk assessments. Guideline 850.1020 should be used as a basis for study development and the registrants should submit a protocol prior to test initiation.

5 Tier II tests required if a tested terrestrial species exhibits a statistically significant detrimental effect in the Tier I st udy.

6 Tier II tests required if a tested aquatic species exhibits a statistically significan t detrimental effect in a Tier I study.

7 Study required for aquatic nonvascular and vascular plants. Test may be conducted with technical grade pyrethrins or a typical end-use product.

8. References

Addy-Orduna, L.M., Zaccagnini, M-E, Canavelli , S.B. and P. Mineau. 2011. Formulated beta

cyfluthrin shows wide divergence in toxicity among bird species. Journal of Toxicology . Volume 2011, Article ID 803451: 10 pages.

Casida J.E., Quistad G.B. Pyrethrum Flowers. Pg. xvii. 1995 Oxford University Press, Inc. New York, New York.

Clark, J.M. and Matsumura, F. 1987. The action of two classes of pyrethroi ds on the inhibition of brain Na-Ca and Ca + Mg ATP hydrolyzing activities of the American cockroach. Comp Biochem Physiol C . 86(1):135-45.

Corbin, M, W. Eckel, M. Ruhman, D. Spatz, N. Thurman, R. Gangaraju, T. Kuchnicki, R. Mathew, and I. Nicholson. 2006. NAFTA Guidan ce Document for Conducting Terrestrial Field Dissipation Studies. Available at url: http://www.epa.gov/oppefed1/ecorisk_ders /terrestrial_field_dissipation.htm (accessed 01/26/11).

Di Toro, DM, CS Zarba, DJ Hansen, WJ Berry, RC Swartz, CE Cowan, SP Pavlou, HE Allen, NA Thomas and PR Paquin. 1991. Technical basis fo r establishing sediment quality criteria for nonionic organic chemicals using equilibrium partitioning. Environ. Toxicol. Chem. 10:1541-
1583.

Ecobichon, Donald J. 1991. Toxic Effects of Pestic ides. In Casarett and Doull's Toxicology, The Basic Science of Poisons, Third Edition. Curtis D. Klaassen, Mary O. Amdur, and John Doull editors. Macmillan Publishing Company, NY.

Essig, K. and Z.J. Zhao. 2001. Preparation and Characterization of a Pyrethrum Extract Standard. LCGC 19 ( 7) July 2001, pp. 722-730, available at www.chromatographyonline.com

.

70European Food Safety Authority, 2008. Draft assessment report for the active substance pyrethrins. Council Direc tive 91/414/EEC. Volume 3, Annex B, Part 5 B.9.

Food and Agriculture Organization of the United Nations. FAO PESTICIDE DISPOSAL SERIES 8. Assessing Soil Contamination: A Re ference Manual. Appendix 2. Parameters of pesticides that influence pro cesses in the soil. Editorial Group, FAO Information Division: Rome, 2000. http://www.fao.org/DOCREP/003/X2570E/X2570E00.htm (accessed 05/20/11)

GfK Kynetec. (1998-2008). EPA Proprietary Data (Cited in BEAD’s Pyrethrins Chemical Profile, USEPA 2011).

Koopmans, M.S.J. 1995. Determination of ‘Rea dy’ Biodegradability: Carbon Dioxide (CO2) Evolution Test (modified Sturm Test) w ith Pyrethrum Extract. Notox B.V. 5231 DDHertogenbosh. The Neatherlands. Kenya Pyre thrum Information Centre. Report No. 141964. GLP, Unpublished (Study cited in Pyrethrins Draft Assessment Report; Rapporteur Member State Italy)

Matsumura, F. 1985. Toxicology of insects. 2nd ed. Plenum New York.

Narahashi, T. 1976. Effects of Insecticides on Nervous Conduction and Synaptic Transmission. Ch. 9 in: C.F. Wilkinson (ed.), Insecticide Biochemistry and P hysiology. 753 pp. Plenum Press,
New York.

Solecky, R. 1999. Pyrethrum Extract (Pyrethrins) (addendum). Journal of Medicinal Plants Research or JMPR 1999, 273-291 [Same informa tion was obtained from IPCS INCHEM Toxicological Evaluations at http://www.inchem.org/documents/jmpr/jmpmono/v99pr11.htm accessed 09/27/2011]

Stewart, D. 1998. The Evaluation of Synergisti c Action in the Laborat ory and Field. p. 173-198

In: Piperonyl Butoxide: the Insecticide Synergist. Academic Press.

Tomlin CDS; The Pesticide Manual. 11 th Ed. Crop Protection Publ: British Crop Protection Council 49 Downing St, Farnham United Kingdom (1997).

USEPA. 2002. Technical Basis for the deriva tion of Equilibrium Partitioning Sediment Guidelines (ESGs) for the Protection of Benthi c Organisms: Nonionic Organics [Draft]. EPA
Document No. 822R02041. October 2002.

USEPA. 2004. Overview of the Ecological Risk Assessm ent Process in the Office of Pesticide Programs . United States Environmental Protection Ag ency (USEPA). Environmental Fate and
Effects Division. Office of Pes ticide Programs. Available at http://www.epa.gov/espp/consultation/ecorisk-overview.pdf (accessed 05/17/2011).

USEPA. 2006a. Reregistration Eligibility Decisi on (RED) Document for N-Octyl bicycloheptene dicarboximide (MGK-264), List B, Case No. 2430, Office of Chemical Safety and Pollution Prevention, Document ID EPA 738-R-06-006, June 2006.

71USEPA. 2006b. Reregistration Eligibility Decision (R ED) Document for Pyrethrins, List B, Case No. 2580, Office of Chemical Safety and Pollution Prevention, Document ID EPA 738-R-06- 004, June 2006.

USEPA. 2007. Hoffmann, M., and J.L. Meléndez. Revised Pyrethrins RED Chapter After Additional 60-Day Comment Period, Phase 5. Memorandum to C. O’Connell dated April 4,
2007. DP Barcode: D338495. OCSPP/OPP/ Envi ronmental Fate and Effects Division

USEPA. 2008. OPPTS 835.6100 Terrestrial Field Dissipation . EPA 712-C-08-020. October 2008. Office of Chemical Safety and Pollution Prevention (formerly Office of Prevention, Pesticides, and Toxic Substances). United States Environmental Protection Agency. Available at http://www.epa.gov/ocspp/pubs/frs/public ations/Test_Guide lines/series835.htm (accessed 05/17/2011).

USEPA. 2011. BEAD Chemical Profile for Regi stration Review: Pyrethrin (PC Code 069001). Memorandum from Biological a nd Economic Analysis Division to Pesticide Reevaluation
Division.

729. Fate and Ecotoxicity Bibliography



## Pyrethrins Environmen tal Fate Bibliography

MRID Citation Reference



### 161-1 Hydrolysis

43188201 Selim, S. (1994) Hydrolysis of Pyrethrin 1 as a Function of pH at 25 degrees C: Lab Project Number: P1092011: 93-1147.BTC. Unpublished study prepared by Biological Test Center. 83 p.

43567502 Selim, S. (1995) Hydrolysis of Pyrethrin 1 as a Function of pH at 25 (degrees) C: Amended Report : Lab Project Numbers: P1092011: 93-1147.BTC. Unpublished study prepared by Biological Test Center. 163 p.



### 161-2 Photodegradation-water

144749 Bullivant, M.; Pattenden, G. (1973) Fundamental photodegradation pathways for rethrolone moieties of the pyrethrin insecticides. Pyrethrum Post 12(2)64-69,75.

164634 Chen, Y.; Casida, J. (1970) Photodecomposition of pyrethrin I, allethrin, phthalthrin, and dimethrin modifications in the acid moiety. Pyrethum Post 10(3):7-16.

43096601 Selim, S. (1994) Aqueous Photolysis of Py rethrin 1: Lab Project Number: P1192006. Unpublished study prepared by Biological Test Center. 87 p.

43567501 Selim, S. (1995) Aqueous Photolysis of Pyrethrin 1: Amended Report: Lab Project Numbers: P1192006: 93-1203.BTC. Unpublished study prepared by Biological Test Center. 170 p.

43567601 Schoenig, G. (1995) Response to EPA Data Evaluation Record for Study Entitled: Aqueous Photolysis of Pyrethrin 1: Lab Project Number: P1192006. Unpublished study prepared by Biological Test Center. 6 p.

43773401 Chen, Y.; Casida, J. (1969) Photodegradation of pyrethrin I, allethrin, phthalthrin, and dimethrin: Modifications in the acid moiety. J. Agr. Food Chem. 17(2):208-215.



### 161-3 Photodegradation-soil

42146 Holmstead, R.L.; Casida, J.E.; Ruzo, L.O. (1976?) Photochemical Re- actions of Pyrethroid Insecticides. (Unpublished study received Aug 22 , 1977 under 10182 -3; prepared by Univ. of California, Dept. of Entomological Sciences, Pesticide Chemistry and Toxi- cology Laboratory, submitted by ICI Americas, Inc., Wilmington, Del.; CDL:096330-A)

60035 Elliott, M.; Farnham, A.W.; Janes, N.F.; et al. (1973) NRDC 145: A more stable pyrethroid. Proceedings of the 7th British Insecti- cide Conference ? :721-728 . (Also~In~unpublished submission received Feb 3, 1977 under 10182-EX-8; submitted by ICI Ameri- cas, Inc., Wilmington, Del.; CDL:228194-B)

66649 Elliott, M.; Farnham, A.W.; Janes, N.F.; et al . (1973) NRDC 143: A more stable pyrethroid. Pages 721-728,~In~Proceedings, 7th British Insecticid e and Fungicide Conference. N.P. (Also~In~

73unpublished submission received Feb 3, 1977 unde r 10182-EX-7; submitted by ICI Americas, Inc., Wilmington, Del.; CDL:228608-B)

113574 Miskus, R.; Andrews, T. (19??) Stabilization of thin films of pyre- thrins and allethrin. Pyrethrum Post:135-136. (Incomplete; also In unpublished submission receive d Jan 21, 1977 under 6296-24; submitted by Nutrilite Products, Inc., Buena Park, CA; CDL:229731-B)

113576 Head, S.; Sylvester, N.; Challinor, S. (19??) Th e effect of pipero- nyl butoxide on the stability of films of crude and refined pyrethrum extracts. ?Source unknown|:14-22. (Also In unpublished submission received Jan 17, 1977 under 6296-24; submitted by Nutrilite Products, Inc., Buena Park, CA; CDL:229731-D)

141553 U.S. Pyrethrum Culture (1984) Application for EPA Registration: Pyrethrum Powder. Unpublished compilation. 581 p.

40700401 Reddy, G. (1988) Analytical Results of Pyrethrin Photolysis Resi- dues after Exposure to Natural Sunlight: SL# 15981-15982. Un- published study prepared by Shrader Laboratories. 96 p.

43096602 Testman, R. (1994) Soil Surface Photolysis of Pyrethrin 1: Lab Project Number: P1192007. Unpublished study prepared by Biological Test Center. 91 p.

43567602 Schoenig, G. (1995) Response to EPA Data Evaluation Record for Study Entitled: Soil Surface Photolysis of Pyrethrin 1: Lab Project Number: P1192007. Unpublished study prepared by Biological Test Center. 13 p.



### 162-1 Aerobic Soil Metabolism

43499803 Robinson, R.A. (1994) Aerobic Soil Metabolism of [14C] Pyrethrin 1 . XBL Study No. XBL93061. XBL Report No. RPT00204. Unpublished Study by XenoBiotic Laboratories, Inc. Plainsboro, NJ and Submitted by Pyrethrin Joint Venture/Chemical Speciaties Manufacturers Association, Washington, DC.



### 162-2 Anaerobic Aquatic Metabolism

43499801 Robinson, R.A. and M.J. Wisocky (1994) Anaerobic Aquatic Metabolism of [14C ] Pyrethrin 1. XBL Study No. XBL93062. XBL Report No. RPT00205. Unpublished Study by XenoBiotic Laboratories, Inc. Plainsboro, NJ and Submitted by Pyrethrin Joint Venture/Chemical Speciaties
Manufacturers Associa tion, Washington, DC.



### 162-4 Aerobic aquatic metab.

43499802 Robinson, R.; Wisocky, M. (1994) Aerobic Aquatic Metabolism of (carbon 14)Pyrethrin 1: Lab Project Number: XBL93063: RPT00193. Unpublished study prepared by Xenobiotic Lab., Inc. 130

p.



### 163-1 Leaching/adsorption/desorption

7443096603 Reynolds, J.; Robinson, R. (1994) Adsorption and Desorption of (carbon 14) Pyrethrin 1 in Four Soils: Lab Project Number: 93064: RPT00156. Unpublished study prepared by XenoBiotic Laboratories, Inc. 123 p.



### 163-2 Volatility - lab

43096604 Selim, S. (1994) Laboratory Volatility of Pyrethrin 1 from Soil: Lab Project Number: P0693011. Unpublished study prepared by Biological Test Center. 101 p.



### 164-1 Terrestrial field dissipation

42745501 Hattermann, D. (1992) LX1180-02 (Pyrethrum + Piperonyl Butoxide) Field Dissipation-Terrestrial Study on Bareground in California, Georgia, and Michigan: Lab Project Number: 91189: 18021E08. Unpublished study prepared by Bio/Dynamics, Inc. 207 p.

43807101 Brookman, D.; Curry, K.; Smith, C. (1995) Data Waiver Request for the Requirement of a Study on Terrestrial Field Dissipation for Degradates of Pyrethrin. Unpublished study prepared by Technology Sciences Group, Inc. 28 p.



### 164-1 Terrestrial fiel d dissipation with PC Code 069000

42900401 Hattermann, D. (1992) Pyrenone Crop Spray (Pyrethrum + Piperonyl Butoxide) Field DissipationTerrestrial Study Applied to Bareground in California, Georgia and Michigan: Field and Analytical Phases: Lab Project Number: 18021E08: 91189. Unpublished study prepared by Landis International, Inc. 220 p.



### 164-2 Aquatic field dissipation

43125701 Hattermann, D. (1994) Piperonyl Butoxide Analytical (and Field) Phase for Pyrenone Crop Spray (Pyrethrin + Piperonyl Butoxide): Aquatic Dissipation Study Applied Post-Emergence to Barewater in California, Arkansas, and Mississippi: Lab Project Number: 18021V09: 91190. Unpublished study prepared by Pharmaco LSR International, Inc. 227 p.

43195201 Hattermann, D. (1994) Pyrethrin Analytical Phase for Pyrenone Crop Spray ( Pyrethrin + Piperonyl Butoxide ) Aquatic Dissipation Study Applied Post-Emergence to Barewater in California, Arkansas, and Mississippi: Lab Project Number: 18021V09: 91190: BD-047-92. Unpublished study prepared by Pharmaco LSR Intern ational, Inc. and Landis International, Inc. 152 p

43818501 Brookman, D.; Curry, K.; Hobson, J.; et al. (1995) Data Waiver Request for the Requirement of a Study on Aquatic Field Dissipation of Pyrethrin. Unpublished study prepared by Technology Sciences Group, Inc. 34 p.



### 165-4 Bioaccumulation in fish

43302301 Schocken, M. (1994) Bioconcentration Study with (carbon 14 ) Pyrethrin 1 in Bluegill Sunfish:

75Final Report: Lab Project Number: 94-5-5258: 11572.0993.6125.140. Unpublished study prepared by Springborn Labs., Inc. 148 p.

43884102 St. Laurent, J. (1995) Development and Validation of an Analytical Methodology for the Determination of Total Pyrethrins in Water, Acetone, and Fish Tissue: Final Report: Lab Project Number: 93-9-4922: 11572.0193.6105.250. Unpublished study prepared by Springborn Labs, Inc. 87 p.



### 201-1 Droplet size spectrum

144487 Palmisano, J. (1984) Letter sent to J. Haus dated Jun 12, 1984: Acute Inhalation LC50: Rat – Particle Size. Unpublished study prepared by Realex Corp. 1 p.

144911 Shaklee Corp. (1984) [Chemistry Data for Shaklee Natural Pesti- cide]. Unpublished compilation . 31 p.

No MRID (Ancillary Data) Dimenna, G.P. and G.P. Schoenig (1993) Summary of Work Performed to Determined Appropriate Storage and Handling Procedures for 14C Pyrethrin 1. Unpublished Study Performed by Toxicology/Regulatory Services. Charlotte sville, VA and Submitted by Pyrethrin Joint Venture/Chemical Specialties Manufacturers Association, Washington, DC.



### 171-4B Residue Analytical Methods

43292701 Hattermann, D. (1994) Pyrethrin Analytical Phase on the Raw Agricultural Commodity residue evaluation of Pyrethrin + Piperonyl Butoxide Applied as Pyrenone Crop Spray to Brassica, including Field Phase for LX1180-20: Final Report: Lab Project Number: 18014A004. Unpublished study prepared by En-CAS Analytical Lab., Ph armaco LSR Internati onal Inc. 472 p.

43298901 Hattermann, D. (1994) Field Phase for LX1180-02 (Pyrethrin + Piperonyl Butoxide) Raw Agricultural Commodity Trials on Fruiting Vegeta ble in Florida, Michigan, New Jersey, North Carolina, California, and Texas: Final Report: in cluding Analytical Phas e: Lab Project Number: 18015A005. Unpublished study prepared by Paragon Global Services, En-Cas Analytical Labs, and Pharmaco LSR International Inc. 272 p.

45398401 Hatterman, D. (2001) Field Phase for LX1180-02 (Pyrethrin + Piperonyl Butoxide) Raw Agricultural Commodity Trials on Brassica in Arkansas, Ca lifornia, Oregon, New York, Florida, Texas and Georgia: Amended Final Report: Lab Project Number: 18014A004: 1714-91-180-02-14D-37/AR. Unpublished study prepared by Landis International, Inc. 503 p.

76

## Pyrethrins Ecotoxicity Bibliography

Avian Oral Toxicity

MRID Citation Reference

42010901 Campbell, S. and S.P. Lynn (1991) An Acute Oral Toxicity Study with Pyrethrum Extract in the Northern Bobwhite Quail. Wildlife International Ltd. Project No. 326-
103. FIFRA Guideline 71-1.



### Avian Dietary Toxicity

MRID Citation Reference

41968801 Grimes, J.; Lynn, S.; Smith, G. (1991) A Dietary LC50 Study with Pyrethrum Extract in the Northern Bobwhite Quail: Lab Project Number: 326-101. Unpublished study prepared by Wildlife Inter- national Ltd. 62 p.

41968802 Grimes, J.; Lynn, S.; Smith, G. (1991) A Dietary LC50 Study with Pyrethrum Extract in the Mallard: Lab Project Number: 326/102. Unpublished study prepared by Wildlife International Ltd. 62 p.



### Acute Toxicity to Freshwater Fish

MRID Citation Reference

43082301 Machado, M. (1994) Pyrethrum Extract (FEK-99): A Flow-Through Acute Toxicity Test with Bluegill Sunfish (Lepomis m acrochirus): Final Report: Lab Project Number: 93/8/4916. Unpublished study prepared by Springborn Laboratories, Inc. 66 p.

43082302 Machado, M. (1994) Pyrenone Crop Spray (Sample Ref. 13650): A Flow-Through Acute Toxicity Test with Bluegill Sunfish (Lepomis macrochirus): Final Report: Lab Report Number 93/11/5008. Unpublished study prepared by Springborn Laboratories, Inc. 66 p.

43082303 Machado, M. (1994) Pyrethrum Extract (FEK-99): A Flow-Through Acute Toxicity Test with Rainbow Trout (Oncorhynchus mykiss): Final Report: Lab Project Number: 93/11/5084. Unpublished study prepared by Springborn Laboratories, Inc. 65 p.

43082304 Machado, M. (1994) Pyrenone Crop Spray (Sample Ref. 13650): A Flow-Through Acute Toxicity Test with Rainbow Trout (Oncorhynchus mykiss): Final Report: Lab Project Number: 93/11/5048. Unpublished study prepared by Springborn Laboratories, Inc. 65 p.

77

### Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

43082305 Putt, A. (1994) Pyrethrum Extract (FEK-99): A Acute Toxicity to Daphnids (Daphnia magna) under Flow-Through Conditions: Final Report: Lab Project Number: 93/11/5082. Unpublished study prepared by Springborn Laboratories, Inc. 71 p

43082306 Putt, A. (1994) Pyrenone Crop Spray (Sample Ref. 13650): Acute Toxicity to Daphnids (Daphnia magna) under Flow-Through Conditions: Final Report: Lab Project Number: 93/11/5075. Unpublished study prepared by Springborn Laboratories, Inc. 82 p.

05009242 Sanders, H.O. (1969) Toxicity of Pesticides to the Crustacean Gammarus Lacustris. Washington, DC, U.S. Bureau of Sport Fi sheries and Wildlife. (U.S. Bureau of Sport Fisheries and Wildlife Technical Paper 25)



### Acute Toxicity to Estua rine/Marine Organisms

MRID Citation Reference

4308
2307 Machado, M. (1994) Pyrethrum Extract (FEK-99): A Flow-Through Acute Toxicity Test with Sheepshead Minnow (Cyprinodon 78ariegates): Final Report: Lab Project Number: 93/12/5081. Unpublished study prepared by Springborn Laboratories, Inc. 64 p.

4308
2308 Machado, M. (1994) Pyrenone Crop Spray (Sample Ref. 13650): A FlowThrough Acute Toxicity Test with Sheepshead Minnow (Cyprinodon 78ariegates): Final Report: Lab Project Number: 93/11/5037. Unpublished study prepared by Springborn Laboratories, Inc. 63 p.

4308
2309 Dionne E. (1994) Pyrethrum Extract (FEK-99): Acute Toxicity to Eastern Oyster (Crassostrea virginica) u nder Flow-Through Conditions: Final Report: Lab Project Number: 93/11/5032. Unpublished study prepared by Springborn Laboratories, Inc. 65 p.

4308
2310 Dionne E. (1994) Pyrenone Crop Spray (Sample Ref. 13650): Acute Toxicity to Eastern Oyster (Crassostrea virginica) under Flow-Through Conditions: Final Report: Lab Project Number: 93/10/4995. Unpublished study prepared by Springborn Laboratories, Inc. 67 p.

4308
2311 Machado, M. (1994) Pyrethrum Extr act (FEK-99): Acute Toxicity to Mysid Shrimp (Mysidopsis bahia) under Flow-Through Conditions: Final Report: Lab Project Number: 93/12/5097. Unpublished study prepared by Springborn Laboratories, Inc. 68 p.

4308
2312 Machado, M. (1994) Pyrenone Crop Spray (Sample Ref. 13650): Acute Toxicity to Mysid Shrimp (Mysidopsis bahia) under Flow-Through Conditions: Final Report: Lab Project Number: 93/12/5077. Unpublished study prepared by Springborn Laboratories, Inc. 67 p.

78

### Fish Early Life Stage/Aquatic In vertebrate Life Cycle Study

MRID Citation Reference

4325 Machado, M. (1994) Pyreth rum Extract (FEK-99)-The Toxicity to Fathead Minnow (Pimephales promelas) During an Early Life-Stage Exposure: Final Report: Lab Project Number: 93-10-4983: 11572. 0193. 6114. 120. Unpublished study prepared by Springborn Lab., Inc. 137 p.

4325 Putt, A. (1994) Pyrethrum Extract (FEK-99)-The Chronic Toxicity to Daphnia magna Under Flow-Through Conditions: Final Report: Lab Project Number: 94-1-5116: 11572.0193.6115.130. Unpublished study prepared by Springborn Lab., Inc. 165 p.



### Honey bee acute contact

MRID Citation Reference

Lynn, S.; Hoxter, K. (1991) An Acute Contact Toxicity Study with Pyrethrum Extract with the Honey Bee: Lab Project No: 326/104. Unpublished study prepared by Wildlife International Ltd. 33

p.

79Appendix A. PRD Data Reque st Justification Tables

The following proposed Data Call-in tables include rationales for requiring the data requested in this problem formulation, explanations of the ut ility of the data, and explanations for how the data might impact risk assessment, following the format provided by PRD.

Guideline Numbers and Study Titles:

• Test Method 100.4 (OCSPP 850.1770, in prep .); Whole sediment: chronic invertebrates freshwater ( Hyalella azteca )

• Test Method 100.5 (OCSPP 850.1760, in prep .); Whole sediment: chronic invertebrates freshwater ( Chironomus dilutus ) US EPA 2001,

• EPA 600/R-01/020 (OCSPP 850.1780, in prep.); Whole sediment: chronic invertebrates marine ( Leptocheirus plumulosus )

Rationale for Requiring the Data

No chronic sediment toxicity tests for freshwater or marine invertebrates have been submitted for pyrethrins to satisfy the Agency’s updated data requirements for outdoor uses in 40 CFR Part 158 (October26, 2007). For pyrethrins, available information indicates that benthic organisms may be exposed via runoff or spray drift applications used in agricultural, forest, and residential settings. Based on calculations in the most recent EFED assessment, the 21-day sedime nt porewater EECs predicted for pyrethrins ranged from 0.03 to 0.20 μg a.i./L (USE PA 2008b). The upper end of this ra nge exceeds 0.1 of the most sensitive
acute LC/EC 50 (1.4 μg a.i./L for mysid shrimp), which satis fies one of the criteria for requiring chronic whole sediment toxicity testing under 40 CFR Part 158. Furthermore, chronic reproductive effects were seen in water column studies with aquatic invertebra tes (daphnids), with a NOAEC = 0.86 μg a.i./L and LOAEC = 2.0 μg a.i./L.

Pyrethrins are expected to persist in sediments, based on half-lives in submitted soil metabolism and aquatic metabolism studies (aerobic soil = 9.5 days; aerobic aquatic metabolism, 10.5 days; anaerobic aquatic metabolism, 86 days) (MRIDs 43499803, 43499802 and 43499801). These half-life values are
exceed the 40 CFR Part 158 criterion of 10 days.

The third set of trigger criteria for requiring chronic testing (K d > 50 or log K OW >3 or K OC > 1000) is also met for pyrethrins (log K OW is 4.5 to 5.9, the average K OC value is 35,200 assuming it is similar to K FOC , and K d is 302 assuming it is similar to K F ). The physicochemical property triggers (K d , K OW and K OC ) reflect the propensity of the chemical to partition onto th e particulate or organic matter phases of sediments. Exceeding any one of the physicochemical property tr iggers listed above is sufficient for indicating the pesticide has reasonable potential for partitioning to the sediment compartment.

Chronic whole sediment tests on Hyalella azteca

, Chironomus tentans , and Leptocheirus plumulosus are requested. Although both are freshwater species, Hyalella and Chironomus differ substantially in their ecological niche (epibenthic v. infa unal species), physiology, and th ere is some evidence suggesting Hyalella is among the more sensitive invertebrates to pyrethroids based on water column tests (Maund et al., 2002; Weston and Jackson, 2009). Pyrethrins have the potential to enter estuarine/marine water bodies based on current usuage patterns that include coastal areas. Therefore, testing is also required for an
estuarine/marine sediment-dwe lling invertebrate species.

Until the final OCSPP guidelines for chronic sediment toxicity tests are published, the registrant should submit a protocol to EFED for approval prior to test initiation.

• Test Method 100.4: Hyalella azteca 42-d Test for Measuring the Ef fects of Sediment Associated Contaminants on Survival, Growth, and Reproduction in USEPA 2000 Methods for Measuring the

80Toxicity and Bioaccumulation of Sediment-associated Cont aminants with Freshwater Invertebrates EPA 600/R-99/064 ( OCSPP 850.1770, in prep. );

• Test Method 100.5: Life-cycle Test for Measuring the Effects of Sediment-associated
Contaminants on Chironomus dilutus (formerly known as C. tentans ) in USEPA 2000 Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates EPA 600/R-99/064 ( OCSPP 850.1760, in prep. ); and

• Leptocheirus plumulosus in USEPA 2001 Method for Assessing the Chronic Toxicity of Marine
and Estuarine Sediment-associated Contaminants with the Amphipod Leptocheirus plumulosus EPA 600/R-01/020 ( OCSPP 850.1780, in prep. ).

Practical Utility of the Data

How will the data be used? Data from sediment toxicity studies will be used to estimate potential risks to benthic organisms associated with uses of pyrethrins. The data will reduce uncertainties associated with the current risk assessment for benthic species and will improve our understanding of the potential effects of permethrin.

How could the data impact the Ag ency’s future decision-making? Although there was uncertainty in estimating the effect of pyrethrins on benthic organisms in previous assessments, there was a potential risk associated with adverse e ffects identified for other aquatic organisms. Acceptable data for benthic organisms will reduce the uncertainty from the previous
assessment If the data indicates th at registered pyrethrins usage may pos e a risk of adverse effects to nontarget benthic organisms above the Agency Level of Concern, the Agency may explore decision options to mitigate this risk. The lack of these data will li mit the flexibility the Agency and registrants have in coming into compliance with the Enda ngered Species Act, and could resu lt in use restrictions which may otherwise be avoided, or which are unnecessarily severe.

81Appendix B. Reported Pyrethrins Ecological In cident Summaries in the EIIS Database

Table C-1. Pyrethrins In cident Report Summaries

Incident # Organism(s) Affected Certainty of
Involvement Legality of
Use Description

I021276-024 Fish ( Cyprinus carpio ) Probable Unknown The Washington Department of Agriculture reported that pyrethrins applied to control mosquitos had drifted to a holding tank and killed 13 koi. No pesticide concentrations were included in the report (Benton County, Washington; 8/17/2003).

I001297-011 Fish (unknown species) Possible Misuse (intentional) A game preserve employee misused Adams Flea and Tick Dust II (active ingredients include pyrethrins, piperonyl butoxide, carbaryl and silica gel by applying it to an ant hill. Heavy rain washed the product into a nearby pond where 5-6 fish were killed. It is
not known which one or what
combination of the four active ingredients is responsible for the mortality. No pesticide concentrations were included in the report (Texas; 9/2/1994).

I019897-001 Cherry trees Probable Misuse (accidental) Cherry trees were damaged by the product PyGanic Crop Protection EC 1.4 (active ingredient pyrethrins). The product was applied at 14 times the
maximum label rate. The trees showed heavy leaf damage and dieback.
Greater than 45% of the orchard trees appeared to be affected. The product was applied a second time to some trees that showed more significant aphid infestation and these trees were affected more severely than others. No pesticide concentrations were included in the report (Polk County, Oregon; 6/2/2008).

I008693-047 Rose bushes Possible Registered

use A homeowner sprayed approximately
12 rose bushes with RosePride Rose and Flower Insect Killer, active ingredients pyrethrins and piperonylbutoxide. The product was then reapplied 2 weeks later. The plants died following the second application. No pesticide concentrations were included in the report (Santa Clara County, California; 4/22/1999).

I010017-017 Ornamental plants Possible Registered

use Severe leaf damage occurred two weeks after application of RosePride

82Table C-1. Pyrethrins In cident Report Summaries

Incident # Organism(s) Affected Certainty of Legality of Description Involvement Use
Rose and Flower Insect Killer to ornamental plants at a residence. The active ingredients in the product are pyrethrins and piperonyl butoxide. No pesticide concentrations were included in the report (Lincoln County, Wisconsin; 3/8/2000).

I008693-046 Unknown plants Possible Registered

use Phytotoxicity occurred following the application of RosePride Rose and Flower Insect Killer (active ingredients pyrethrins and piperonyl butoxide) to unknown plants at a residence. No pesticide concentrations were included in the report (Muskegon County, Mississippi; 4/30/1999).

I008693-046 Rose bushes Possible Registered

use A homeowner reported that RosePride Rose and Flower Insect Killer (active ingredients pyrethrins and piperonyl butoxide) caused 6 or 7 roses to turn brown following application of the product. A rose that was not sprayed remained healthy. No pesticide
concentrations were included in the report (Sarasota County, Florida; 2/2/2000).

83

### Appendix C. Pyrethrins Down-the -Drain Risk Assessment

Summary: No RQ exceeded any of the acute or chronic LOCs. These results were based on the following assumptions:

1. A highly conservative production volume va lue (all consumer indoor + PCO production volume);
2. Default wastewater treatment half-lives (10,000 hr or ~417 days). It is noted that the
EPISuite v.4.0 modeled ha lf-lives are 30-300 hr;
3. A stream dilution factor of 1.00 ( i.e. , no dilution) that results fr om the use of the high end (or 10 th percentile) concentration, which may be compared to SDF = 20-24 for the 50 th percentile. The 10 th percentile concentration represents small receiving streams while the
50 th percentile represents midsized stream flows.

Rough Estimate of the Production Volume

This section shows how a rough estimate of the production volume was obtained.

In the current assessment, a conservative appr oach that all non-agri cultural uses with a potential to be used and disposed through domestic wastewater s, was equivalent to the production volume is used.

Table C-1. Non-agricultural use of pyrethrin s across recent years in various site categories 1, 2

Year Market Segment Sum Of Pounds A.I. Approx. Ave. lbs A.I.

2000 Consumer - Indoor 52,000 ~82,500 2005 Consumer - Indoor 113,000

2008 Food Handling <500

Not Applicable to the
Down-the-Drain

Assessment 2006 Institutional Turf <500

2002 Lawn Care Operators (LCOs) 3,000

2006 Lawn Care Operators <500

2003 Mosquito Abatement 2,000

2005 Mosquito Abatement 12,000

2002 Nursery/Greenhouse <500

2004 Nursery/Greenhouse <500

2006 Nursery/Greenhouse <500

2003 Pest Control Operator (PCO) 9,000 9000 Rough estimate of the production volume from non-agricultural uses with potential to be used indoors; value is considered conservative. ~91,500 lb (or ~41,500 kg)
1. Data source : Kline and Co., proprietary market surveys, 2002-2008
2. The area of the table shaded yellow was adapted from BEAD’s Chemical Profile for Pyrethrins (USEPA 2011). Area shaded blue ( i.e. , column with average pounds and row providing the rough estimated total A.I. for non-agri cultural uses that could potentia lly reach POTWs) was added by

EFED.

Because it is a very unrefined value, the production volume was rounded to one significant figure.

84Table C-2. Pyrethrin 1 down-the- drain input values and results

Production Vol. BCF (whole fish) WWT (%) a Acute EEC (ppb, 1Q10) b Chronic EEC (ppb, 7Q10) b ~40,000 kg A.I. 471 x 91.7 0.0806 0.0806

1. A removal of 91.7% is obtained from EPISuite v.4.0 using the default treatment t 1/2 ’s (10,000 hr).
2. 1Q10 - single day of lowest flow over a 10-year period (stream dilution factor = 1.00 means not dilution) 7Q10 - 7 consecutive days of lowest flow over a 10-year period (conservative stream dilution factor also = 1.00)

Table C-3. Acute and chronic RQs for freshwater fish associated with “down-the-drain” uses of pyrethrins based on rainbow trout LC 50 = 5.1 ug/L and fathead minnow NOAEC = 1.9 ug/L; and, acute and chronic RQs for freshwater invertebrate s associated with ‘down-the-drain” uses of pyrethrins based on Daphnia magna EC 50 = 11.6 ug/L and Daphnia magna NOAEC = 0.86 ug/L.

Peak EEC

( μ g/L) Chronic EEC ( μ g/L) FW Fish Acute RQ FW Fish Chronic RQ FW Invert Acute RQ FW Invert Chronic RQ 0.0806 0.0806 0.02 0.04 0.01 0.09

The production volume needs to be above ~125,000 kg to cause the RQ to exceed the acute endangered species LOC of 0.05, and above ~425,000 kg to cause the RQ to exceed the chronic
LOC of 1.00.

85Running E-FAST’s Down-the-Drain Module

Physical/Chemistry Input Screen : Chemical’s ID = Pyrethrin 1;
BCF = 471
Wastewater treatment removal = 91.7% MW = 328.4 g/mol
Choose modules: Down-the-Drain & Probabilistic Dilution Model (PDM)

Consumer Disposal Input Screen : Production Volume = 40,000 kg/yr Exposure Duration = 57 yr
Choose: Run in PDM High End Scenario

Select “Run Disposal Model”

86Partial Output Files from EPISuite v.4.0 for Pyrethrin 1 (only STP results are shown)

STP Fugacity Model: Predicted Fate in a Wastewater Treatment Facility

====================================================================== (using 10000 hr Bio P,A,S) PROPERTIES OF: Cyclopropanecarboxylic acid, 2,2-dimethyl-3-(2-methyl-1- propenyl)-, 2-methyl-4-oxo-3-(2,4-pentadienyl)-2-cyclopenten-1-

------------- Molecular weight (g/mol) 328.46 Aqueous solubility (mg/l) 0 Vapour pressure (Pa) 0 (atm) 0 (mm Hg) 0 Henry 's law constant (Atm-m3/mol) 7.73E-007 Air-water partition coefficient 3.16134E-005 Octanol-water partition coefficient (Kow) 794328 Log Kow 5.9 Biomass to water partition coefficient 158866 Temperature [deg C] 25 Biodeg rate constants (h^-1),half life in biomass (h) and in 2000 mg/L MLSS (h): -Primary tank 0.00 9968.63 10000.00 -Aeration tank 0.00 9968.63 10000.00 -Settling tank 0.00 9968.63 10000.00

STP Overall Chemical Mass Balance:

--------------------------------- g/h mol/h percent

Influent 1.00E+001 3.0E-002 100.00

Primary sludge 5.81E+000 1.8E-002 58.08 Waste sludge 3.28E+000 1.0E-002 32.83 Primary volatilization 1.28E-005 3.9E-008 0.00 Settling volatilization 2.87E-005 8.7E-008 0.00 Aeration off gas 7.09E-005 2.2E-007 0.00

Primary biodegradation 1.70E-002 5.2E-005 0.17 Settling biodegradation 4.20E-003 1.3E-005 0.04 Aeration biodegradation 5.53E-002 1.7E-004 0.55

Final water effluent 8.32E-001 2.5E-003 8.32

Total removal 9.17E+000 2.8E-002 91.68 Total biodegradation 7.66E-002 2.3E-004 0.77

8788 Partial Output File from E-FAST: Surfa ce Water Aquatic Exposure Estimates (EECs)

WWT
REMOVAL (%) PRODUCTION
VOLUME

(kg/yr) HOUSEHOLD
RELEASE

DAYS PRETREATMENT
RELEASE (g/person/day) POST-TREATMENT
RELEASE (g/person/day) BODY
WEIGHT (kg) BCF (L/kg)

91.7 4.00E+04 365.00 3.77E-04 3.13E-05 71.80 471.00

50 th PERCENTILE AQUATIC EXPOSURE ESTIMATES - SURFACE WATER

DESCRIPTOR Harmonic Mean 30Q5 7Q10 1Q10

STREAM DILUTION FACTOR 134.85 39.66 24.22 20.08

CONCENTRATION ( μ g/L) 5.98E-04 2.03E-03 3.33E-03 4.01E-03

10 th PERCENTILE AQUATIC EXPOSURE ESTIMATES - SURFACE WATER

DESCRIPTOR Harmonic Mean 30Q5 7Q10 1Q10

STREAM DILUTION FACTOR 7.95 1.80 1.00 1.00

CONCENTRATION ( μ g/L) 1.01E-02 4.48E-02 8.06E-02 8.06E-02