UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON D.C., 20460

OFF ICE O F

CHEMICAL S AFETY AND

POLLUTION PR EV EN TI ON



### PC Code: 09980 

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DP Barcode: D423166

Date: October 29, 2015

MEMORANDUM

SU BJ EC T : Tran s mitt a l of th e Preliminar y E n v i ro nm e ntal Fate a nd Eco lo g i cal Ri s k

A ssess m e nt fo r th e Re gis trati o n R ev i ew of E th ephon



### T O:

FROM: Marquea Kin g, C hemical R ev i ew Manager

Jill Bl oo m

, Team L ead e r

Linda Arri n gton, Bran c h C hi ef

Ri sk Mana ge m e nt and Impl e m e nt a ti o n Branch 5

P es ti c id e R e-Eva lu a ti o n Di v i s i o n (7 508P)

Na th a n Mi ll e r

, Bio l og i s t

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I brahim Abde l -Sa h e b

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, Env ironm e nt a l Scienti st ''

E n v ironmen t a l Ri s k B ra n c h V I

E n v ironm e nt a l Fa t e a nd E ff ec t s Di v i s i o n (7507 P )



### REVIEWED (), 

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BY: Amy Blankin s hip

, Seni o r Biol og i st

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Monica Wait

, Ri s k Assess m e nt Pro cess Leade r 

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E n v ironm e ntal Ri s k B ra nch V I

E n v i ro nm e n ta l Fate and Effec t s Di v i s i o n (7507P)



### THROUGH: Mark Co rbin

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E n v ironm e n ta l Fate and E ffects Di v i s ion (7507

This memorandum tr a n s mit s th e pr e liminar y eco l og i ca l risk assessment for the regi s tration

r ev i ew of e th ep h on (2

- c hl oroe th y l pho s phonic ac id ; CAS No.: 16672-87-0 ; PC Code 099801).

Afte r review in g th e mo s t r ece nt e n v i ro nment a l fa t e a nd effec t s data fo r e thephon

, the assess m e nt

conclude s t h a t r eg i ste r ed u ses of t h e pl an t growt h r eg ulat or e th ep h o n ma y r es u l t in ri sks th at

exceed b ot h l i s t ed a nd n o n-li s t e d s p ec i es LOC s for b ird s, m a mm a l s, a nd t e rre st rial pl a nt s

, and

li s t e d species LO Cs for a qu a ti c vasc ul a r pl a n t s.- Page 2 of 87

-



# Environmental Fate and Ecological Risk Assessment

for the Registration Review of Ethephon

2

- chloroethylphosphonic acid

CAS Registry Number: 16672

- 87

- 0

PC Code: 099801

Prepared b

y :

Nathan Miller

, Biologist

Ibrahim Abdel

- Saheb , Ph.D.

, Environmental Scientist U.S. Enviro nmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

(EFED)

Environmental Risk Branch V I

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington, DC 20460 Reviewed by:

Amy Blankinship , Senior Biologist

Andrew Shelb y, Physical Scientist

Monica Wait, Risk Assessment Process Leader

Mark Corbin

, Branch Chief



### October 29 , 2015- Page 3 of 87

-



## Table of Contents

1. Executive Summary

................................ ................................ ................................ .............. 4

2. Problem Formulation

................................ ................................ ................................ ........... 6

2.1. Nature of Regulatory Action

................................ ................................ ........................ 6

2.2. Stressor Source and Distribution

................................ ................................ ................ 7

2.2.1. Nature of the Stressor

................................ ................................ ................................ .......................... 7

2.2.2

. Overview of Pesticide Use

................................ ................................ ................................ .................. 8



### 2. 3. Receptors

................................ ................................ ................................ ....................... 8

2.3.1. Aquatic and Terrestrial Effects

................................ ................................ ................................ ............ 8

2.3.2. Ecosystems Potentially at Risk

................................ ................................ ................................ ............ 9



### 2.4. Assessment Endpoints

................................ ................................ ................................ .. 9

2.5. Conceptual Model

................................ ................................ ................................ ........... 9

2.5.1. Risk Hypotheses

................................ ................................ ................................ ................................ 10

2.5.2. Conceptual Pathways Table

................................ ................................ ................................ .............. 10



### 2.6. Analysis Plan

................................ ................................ ................................ ................. 12

2.6.1. Residu es of Concern

................................ ................................ ................................ .......................... 12

2.6.2. Measures of Exposure

................................ ................................ ................................ ....................... 12

2.6.3. Measures of Effect

................................ ................................ ................................ ............................. 15

2.6.4. Integration of Exposure and Effects

................................ ................................ ................................ .. 16



### 3. Analysis

................................ ................................ ................................ ............................. 18

3.1. Use Characterization

................................ ................................ ................................ .. 18

3.2. 3.2. Exposure Characterization

................................ ................................ ................. 21

3.2.1. Environmental Fate and Transport Characterization

................................ ................................ ......... 21

3.2.2. Measures of Aquatic Exposure

................................ ................................ ................................ .......... 25



### 3.2.3. Measures of Terrestrial Exposure

................................ ................................ ............. 28

3.3. Ecological Effects Characterizatio n

................................ ................................ .......... 35

4. Risk Characterization

................................ ................................ ................................ ......... 43

4.1. Risk Estimation

................................ ................................ ................................ ................... 43

4.2. Inc ident Database Review

................................ ................................ ................................ .. 52

4.3. Risk Description

................................ ................................ ................................ .................. 54

4.3.1 Risk to Aquatic Organisms

................................ ................................ ................................ ................ 54

4.3.2. Risk to Terrestrial Organisms

................................ ................................ ................................ ............ 55



### 4.4. Uncertainties and Data Gaps

................................ ................................ ..................... 60

4.4.1. Fate and Transport

................................ ................................ ................................ ............................. 60

4.4.2. Effects

................................ ................................ ................................ ................................ ................ 61



### 5. Endocrine Disruptor Screening Program (EDSP)

................................ ........................... 61

6. Federally Threatened and Endangered (Listed) Species Concerns

............................... 61

7. Conclusions

................................ ................................ ................................ .......................... 63

8. References

................................ ................................ ................................ ............................ 64

8.1 Submitted Product Chemistry and Environmental Fate Studies

................................ ... 66

8.2. Submitted Ecotoxicity Studies

................................ ................................ ........................... 70- Page 4 of 87

-



## Appendices

Appendix A. Selected SWCC Output Files

................................ ................................ ................. 77

Appendix B. Toxicity Categories and Levels of Concern

................................ ........................... 79

Appendix C . Example T

- REX (v. 1.5.2) Input and Output for Ethephon

................................ ... 80

Appendix D . STIR Results

................................ ................................ ................................ .......... 82

Ap pendix E . Screening Imbibition Program (SIP) Version 1.0 Inputs and Results

.................... 83

Appendix F

. A cce p t ed E C O T O X D a t a Ta b l e (200 9 Report)

................................ ...................... 84

1. Executive Summar y

The Environmental Fate and Effects Division ( EFED ) has completed the preliminary ecological

risk assessment for the Registration Review of ethephon (2

- chloroethylphosphonic acid; CAS

No .: 16672

- 87

- 0 ; PC Code 099801 ) and its end

- use product s

. Ethephon i s an

o rganophosphonate plant growth regulator intended to promote fruit ripening, abscission, flower

induction, breaking of apical dominance (inhibition of the growth of lateral buds by the terminal

bud of a shoot), and other plant responses through the re lease of ethylene gas, a natural plant

hormone . It has been registered in the United States for more than 40 years for use on a number

of terrestrial food, feed and nonfood crops, greenhouse food crops and outdoor residential plants.

Ethephon is applied as a broadcast foliar spray via ground, aerial, or backpack sprayer

equipment. Application rates range from 0.25 pounds of active ingredient per acre ( lb a.i./A ) for

a niche use on cucurbit crops for hybrid seed production (applied up to six times at a mi nimum

of three day interval) to 4 lbs a.i./A for turf (applied up to five times at a minimum of 14 day

interval). The highest registered ethephon use rate for a food crop is a single application at 2 lbs

a.i./A on apples, berries, pineapples , and tobacco

.

E thephon is characterized as nonvolatile, soluble compound that is slightly t o moderately mobile

in soil. Ethephon dissipates in the environment through both biotic and abiotic degradation and

by leaching in soils that are low in organic carbon. Therefor e, there is slight potential for

ethephon to accumulate in soil with repeated applications. E thephon is not expected to

bioaccumulate due to its low K

ow 

### ( ≤6.3 x 10

- 3 

### ).

Potential Risks to Non

- target Organisms

Summary of the Major Risk Conclusions for Aqu atic Taxa

Fish and Aquatic Invertebrates. The estimated environmental concentration are well below

ecotoxicity study

- defined toxic thresholds, such that neither acute nor chronic effects to fish or

aquatic invertebrates are expected. There were no leve ls of concern (LOC) exceedances of listed

and non

- listed species of fish or aquatic invertebrates for the registered uses of ethephon.- Page 5 of 87

-



### Aquatic Plants

. Risk Quotients (RQs) do not exceed the LOC for non

- listed aquatic vascular

plants or listed or non

- lis ted species of aquatic non

- vascular plants. For ethephon used on turf,

ornamentals, and cotton, risk exceeds the LOC for listed species of aquatic vascular plants. The

LOC exceedance s for these three use patterns may be overestimated by the absence of a

definitive no

- adverse effect concentration ( NOAEC ) in the available study

.

Summary of the Major Risk Conclusions for Terrestrial Plants and Animals

Terrestrial Plants

. There is potential for adverse effects to non

- target plants based on

ethephon ’s plant growth regulator mode of action

. The available terrestrial plant studies

demonstrate that effects to non

- target plants occur at rates well below the maximum labeled

application rates. RQs exceed the LOC for listed and non

- listed terrestrial plants, and t he extent

of adverse effects from spray drift in terms of distance away from the treated field exceed the

AgDRIFT model range (>997 feet) for multiple use sites. Additionally, t here are seven

terrestrial plant incidents associated with ethephon use which reinforce the certainty of adverse

effects

.

Birds and Surrogates (Reptiles and Terrestrial Amphibians )

. There is a potential for adverse

chronic effects ( e.g.

, reduced number of hatchling, reduced survival of hatchlings) and acute

effects for birds consum ing short grass, tall grass, broadleaf plants/small insects, and arthropods

(RQ s exceed acute listed, acute non

- listed, and chronic risk LOCs for multiple use patterns).

Mammals

. There is a potential for adverse chronic effects ( e.g.

, reduced offspring bodyweight)

and acute effects for mammals consuming short grass, tall grass, broadleaf plants/small insects,

and arthropods (RQs exceed acute listed, acute non

- listed [turf use pattern only] , and chronic risk

LOCs for multiple use patterns ).

Honey Bees and Terrestrial Invertebrates

. Acute oral and contact honey bee ( Apis mellifera )

toxicity data indicate that the likelihood of adverse effects from exposure to ethephon is

considered low (RQ<LOC) for all use patterns. However, c hronic oral toxicity data for young

adult bees and acute and chronic larval honey bee data are not available to fully evaluate the

potential for effects to individual adult honey bees or their bro od (eggs, larvae, and pupae), and

risk is uncertain.

Data Gaps and Uncertainties

Fat e and ecotoxicity data gaps discussed in Section 4.4 . There are no significant data gaps in the

environmental fate database submitted by the registrant. F ate data submitted with the RR DCI

–

aerobic soil metabolism studies MRIDs 48202001 (MRIDs 48202002 was classified as

unacceptable) and aerobic aquatic metabolism MRID 48202003 were considered in this

assessment. Submitted independent laboratory validation (ILV) studies for these ECMs (MRIDs

49305601, 49305603) are in review

.

The main ecotoxicity uncert ainties in the risk assessment concern terrestrial plants and terrestrial

invertebrates, because the available toxicity data are not comprehensive

. For terrestrial plants, a- Page 6 of 87

-



### no effect concentration could not be established for the most sensitive dicot spe cies tested in the

vegetative vigor study design. In lieu of a NOAEC, the EC 05 

### is used to estimate risk to listed

terrestrial dicots, consistent with EFED policy. Concerning terrestrial invertebrates, chronic

dietary risk to adult honeybees and acute and chronic dietary risk to larval honeybees is uncertain

due to a lack of data. Honey bee risk assessment guidance has recently been finalized and

recommends the following honey bee data for a Tier I screening

- level risk assessment for bees:

 acute oral toxi city to adult honey bees;

 acute oral toxicity to larval honey bees;

 chronic oral toxicity to adult honey bees; and,

 chronic oral toxicity to larval honey bees.

Acute oral toxicity data for adult honey bees are available

, and no effects were seen at an

acc eptable limit dose . H owever, i f the other Tier I studies identify the potential for a risk

concern, additional studies may be requested ( i.e.

, semi

- field testing for pollin ators [special

study, Tier II] , f

ield testing for pollinators [OCSPP 850.3040, Tier III] , and field trial of residues

in pollen and nectar [special study, Tier III] )

. Since these data are currently unavailable for

ethephon , the potential for adverse effects to individual honey bees and their brood is uncertain

.

2. Problem Formulation

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

ecological risk assessment for the R egistration R eview of the o rganophosphonate plant growth

regulator ethephon (2

- chloroethylphosphonic acid; CAS No .: 16672

- 87

- 0 ; PC Code 099801 ) and

its end

- use products. The problem formulation sets the objectives for the risk assessment,

establishes a risk hypothesis and conceptual model depicting potential routes of exposure,

biological receptors and their measurement endpoi nts , and it provides a plan for analyzing the

data and characterizing the risk associated with the use of ethephon (USEPA, 1998)

.

2.1. Nature of Regulatory Action

Under the Federal Insec ticide, Fungicide, and Rodenticide Act (FIFRA), all pesticides distributed

or sold in the United States must be registered by the United States Env ironmental Protection

Agency ( EPA). To determine whether a pes ticide can be registered, the EPA evaluates it s safety

to non

- target species based on a wide range of environmental and health effects studies. In 1996,

FIFRA was amended by the Food Quality Protection Act (FQPA), and EPA was mandated to

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

., R egistration R eview 1 

### . The

R egistration R eview program is intended to ensure that as the ability to assess risk evolves and as

policies and practices change, all registered pesticides continue to meet the statutory standard of

no unreasonable adverse effects to human health and the environment. Changes in science,

public policy, and pesticide use practices will occur over time. Through the registration review

program, the Agency periodically reevaluates pesticides to make sure that as change s occur

, products in the marketplace can be used safely.

1 http://www.epa.gov/oppsrrd1/registration_review/- Page 7 of 87

-



### 2.2. Stressor Source and Distribution

2.2.1. Nature of the Stressor

Ethephon is an organophosphonate plant growth regulator intended to promote fruit ripening,

abscission, flower induction, breaking of ap ical dominance (inhibition of the growth of lateral

buds by the terminal bud of a shoot), and other plant responses. Ethephon is not a plant hormone

per se ; however, its princip a l degradation product, ethylene, is a natural plant hormone that is

distribut ed systemically in plants (Archer et al. , 1973), and exerts effects on plant physiology

. A

Reregistration Eligibility Decision ( RED ) for ethephon was published in 1995 (USEPA, 1995 ).

In 2006, an ecological risk assessment was conducted for proposed new u ses of ethephon on

filbert and coffee to aid in harvesting (DP 324040). In 2010, a P reliminary P roblem F ormulation

for Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure

Assessments for Ethephon was conducted (DP 371952 ).

An o rganophosphonate pesticide

, ethephon demonstrates inhibition of plasma

butyr y lcholinesterase ( EPA R.E.D. Facts Ethephon , 1995 ) in mice. However, its single

degradate retain s the phosphate moiety, 2

- hydroxyethylphosphonic acid (H EPA), and does not

inhibit plasma butyr y lcholinesterase (see chemical structures in Table 8 ). The Health Effects

Division ( HED) completed a screening level review of comparative toxicity studies of ethephon

and HEPA that were submitted. This review conclu ded that the HEPA metabolite does not pose a

concern for risk assessment ( USEPA , 2002)

.

Ethylene does not contain the organophosphonate moiety of the ethephon molecule. Therefore,

although ethephon may inhibit cholinesterase in animals, no degradates o f ethephon are expected

to do so. The 1992 RED for ethylene (PC 041901) confirms that ethylene is not a cholinesterase

inhibitor ( USEPA, 1992). Ethephon alone is the residue of concern for animals in this

assessment.

The biologically active degradate of ethephon, ethylene, is a degradate of concern for plants in

this risk assessment, as it demonstrates a phytohormonal mode of action that could have adverse

effects on plant growth. Therefore, ethephon and ethylene are the residues of concern for plants

i n this assessment. Table 1 summaries the chemical profile of ethephon.- Page 8 of 87

-



### Table 1 . Chemical Profile of Ethephon.

Common name Ethephon

Chemical name

Chemical formula [(2

- chloroethyl) phosphonic acid]

C 2 

### H 6 

### ClO 3 

### P

Structure

SMILES Notation C(CCl)P(=O)(O)O

Pesticide type plant growth regulator

Chemica l class Organophos phon ate

CAS number 16672

- 87

- 0

Molecular Weight 144.5 g/mol

2.2.2

. Overview of Pesticide Use

Ethephon was first registered in the United States in 1973 to promote fruit ripening, abscission,

flower induction, breaking of apical domi nance and other plant responses. Ethephon currently has

43 active registered products for use on terrestrial food, feed and nonfood crops, greenhouse food

crops and outdoor residential plants. Ethephon end use products are formulated as flowable liquids

a nd soluble concentrates. Broadcast a pplication s to plant foliage are made by either ground or

aerial equipment. Ethephon may also be applied by hand sprayer to select home garden

vegetables. The turf use represents the highest application rate: 3.4 lb a .i/A, 6 applications, 28

- day

interval. This assessment evaluates risk based on currently labeled maximum application rates.

2.3. Receptors

2.3.1. Aquatic and Terrestrial Effects

The receptor is the biological entity that is exposed to the stressor (USEPA, 1998) . Consistent

with the process described in the Overview Document (USEPA, 200 4a) , this risk assessment uses

a surrogate species approach. T oxic ity data generated from surrogate test species, which are

intended to be representative of broad taxonomic groups, are used to extrapolate potential effects

on a vari ety of species (receptors) included under these taxonomic groupings.

A cute and chronic toxicity data from studies submitted by pesticide registrants along with the

available open literature are used to evaluate potential direct effects to aquatic and te rrestrial

receptors. The open literature studies are located through EPA’s ECOTOXicity database

( ECOTOX ; http://cfpub.epa.gov/ecotox/ ), which provides a source for locating single chemical

toxicity data for aqu atic life, terrestrial plants, and wildlife.- Page 9 of 87

- 

### 2.3.2. Ecosystems Potentially at Risk

The ecosystems potentially at risk are often extensive in scope; therefore, it may not be possible

to identify specific ecosystems during the development of a nation

- wide ecological risk

assessment. However, in general terms, terrestrial ecosystems potentially at risk could include

the treated field or tree(s) and immediately adjacent areas that may receive spray drift or runoff.

Areas adjacent to the treated field o r tree(s) could include cultivated fields, fencerows and

hedgerows, meadows, fallow fields or grasslands, woodlands, riparian habitats, and other

uncultivated areas.

Aquatic ecosystems potentially at risk include water bodies adjacent to or downstream f rom use

sites, and might include natural or impounded lentic water bodies such as ponds, lakes and

reservoirs, or flowing waterways such as streams or rivers including all adjacent off

- channel

habitats that are permanently or intermittently connected to fl owing waters. For uses in coastal

areas, aquatic habitat also includes marine ecosystems, including estuaries, embayments, and

near

- shore environments such as tidal marshes.

2.4. Assessment Endpoints

Assessment endpoints represent the actual environmen tal value that is to be protected, defined by

an ecological entity (species, community, or other entity) and its attribute or characteristics

(USEPA, 1998) . For ethephon , ecological entitie s of potential concern include the following:

birds, terrestrial

- and aquatic

- phase amphibians, reptiles, mammals, freshwater fish and

invertebrates, estuarine/marine fish and invertebrates, non

- target terrestrial plants, terrestrial

invertebrates, and aq uatic vascular and non

- vascular plants. The attributes for each of these

entities include gro wth, survival, and reproduction

.

The assessment endpoints are intended to reflect population sustainability and community

structure within ecosystems and hence r elate back to ecosystems at risk. If risks are expected for

given species/taxa based on the screening

- level assessment, then risks might be expected to

translate to higher levels of biological organization.

2.5. Conceptual Model

For a pesticide t o pose an ecological risk, it must reach ecological receptors in biologically

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

environment from a source to an ecological receptor. For an ecological pathway to be complete,

it must have a source, a release mechanism, an environmental transport medium, a point of

exposure for ecological receptors, and a feasible route of exposure. The conceptual model is

intended to provide a written description and visual repre sentation of the predicted relationships

between ethephon , potential routes of exposure, and the predicted effects for the assessment

endpoint. The conceptual model consists of two major components: the risk hypotheses and a

conceptual model (USEPA, 1998)

.

The conceptual model used to depict the potential ecological risk associated with the existing

uses of ethephon relies on previous assessments and the Agency’s current understanding of th e- Page 10 of 87

-



### environmental fate and ecological effects of the chemical. Consistent with the intended use of

ethephon as a plant growth regulator

, risk to non

- target terrestrial and aquatic plants is expected.

Effects on plants, which represent the primary producers in an ecosystem, may result in

secondary effects on consumers which may include a broad range of taxa

.

2.5.1. Risk Hypotheses

For ethephon , the following gener ic ecological risk hypotheses are being employed for this risk

assessment:

Given the curre ntly labeled uses of ethephon and its environmental fate properties, there

is a likelihood of exposure to non

- target terrestrial and aquatic organisms.

When used in accordance with the label, ethephon may result in potential adverse effects

upon the sur

vival, growth, and reproduction of non

- target terrestrial and aquatic

organisms.

2.5.2. Conceptual Pathways Table

The environmental fate properties of ethephon indicate that for foliar applications

, spray drift and

runoff (inclu ding of eroded sediment) are potential transport mechanisms to aquatic habitats

where non

- target organisms may be exposed. It is expected that non

- target terrestrial organisms

can be exposed via foliar applications of ethephon through consumption of expos ed plants and

invertebrates on treated field s . Additionally, ethephon may reach terrestrial environments off the

field via spray drift. A summary of the transport pathways and the models used for those

pathways in the assessment are provided in Table 2

.

Ethephon is not persistent in the environment. The major routes of dissipation appear to be

chemical hydrolysis under neutral and alkaline conditions and microbial degradation. Although

ethephon does degrade fairl y rapidly in somewhat acidic soils (pH 6.1) under aerobic and

anaerobic conditions, it does not hydrolyze in sterile, acidic water (pH 5). The major degradates

of ethephon are ethylene gas and 2

- hydroxy ethyl phosphonic acid (HEPA) , the latter formed by

mi crobially mediated hydrolytic dehalogenation. Ethephon can be characterized as having

moderate to low mobility in soil. The mobility of the soil degradate 2

- hydroxy ethyl phosphonic

acid is slightly to hardly mobile (Kfoc range of 1460

– 12100 L/kg). Etheph on is reported to have

a very low octanol/water partition coefficient ( K ow <0.00626), therefore, it is not expected to

accumulate in fish.

Additionally, the Screening Tool for Inhalation Risk (STIR) version 1.0 (November 23, 2010)

indicates that ethephon exposure via inhalation is not likely to be a risk concern for birds and

mammals ( Appendix D ). Another screening tool, t he Screening Imbibition Program (SIP v.1.0,

released June 15, 2010) was used to calculate an upper

- bound estimate of wildlife drinking water

exposure . The SIP screening tool indicates that drinking water exposure alone is considered a

potential pathway of concern for birds or mammals on either an acute or chronic exposure basis

based on solubility and available toxicity data (- Page 11 of 87

-



### Appendix E )

.

The exposure pathways may result in exposure to various aquatic and terrestrial organisms.

With exposure, the following attribute changes have the potential to occur:

 e ffects to individual organisms ;

 e ffect s to the food chain (reduction in prey and food, modification of primary constituent

elements (PCE) related to prey availability) ; and

,

 e ffects to habitat integrity (reduction in primary productivity, reduced cover, community

change, and modification of PC E related to habitat).

Table 2 . List of the Various Models and the Related Taxa for which the Models will be

Used to A ssess R isk

.

Environment Taxa of Concern Exposure

Media Exposure

Pathway Model(s) or

Pathway Attribute Change

Aqu atic Vertebrates/

Invertebrates

(including

sediment

dwelling) Surface water and

sediment Runoff and spray

drift to water and

sediment SWCC Individual Organisms

Food Chain

Habitat Integrity

Aquatic Plants

(vascular and

nonvascular) Food Chain

Habitat Integrity

Riparian plants See terrestrial exposure pathways Habitat Integrity

Terrestrial Vertebrate Dietary items Ingestion of

residues in/on

dietary items as a

result of direct

application T

- REX Individual Organisms

Food Chain

Habitat Integrity

Co nsumption of

aquatic organisms Residues taken up

by aquatic

organisms KABAM Individual Organisms

Food Chain

Habitat Integrity

Plants Spray drift/runoff Runoff and spray

drift to plants TERRPLANT

Food Chain

Habitat Integrity Surface water Residues in

irrigation water Not a major

transport pathway

Groundwater

Bees and other

terrestrial

invertebrates 1 Contact

Dietary items Spray contact and

ingestion of

residues in/on

dietary items as a

result of direct

application See honey bee risk

assessme nt

guidance (USEPA

et al ., 2014) Individual Organisms

Colony/Population

Integrity

All

Environments All Movement through

air to aquatic and

terrestrial media Spray drift AgDRIFT (Spray

drift) Individual Organisms

Food Chain

Habitat Integrity Atmospher ic

transport

2 Not a major

transport pathway

Text in italics represent transport pathway s that are not of concern.

1 See pollinator SAP white paper for full list of modelling approaches for evaluating exposure used in this

assessm ent (USEPA, 2012b)

.

2 Ethephon is non

- vo latile. Gaseous ethylene will be degraded in the atmosphere by reaction with photochemically

-- Page 12 of 87

-

produced hydroxyl radicals with DT 50 of 24 hours; therefore, it is not likely to disperse via atmospheric transport.



### 2.6. Analysis Plan

2.6.1. Residues of Concern

Ethephon alone is the stressor of concern for animals in the risk assessment. Ethephon’s single

organophosphate degradate, HEPA, does not inhibit plasma butyr yl cholinesterase (Morton,

2002). Therefore, the degradates of ethephon are not expec ted to be cholinesterase inhibitors and

are not of toxicological concern for animals.

The biologically active degradate of ethephon, ethylene gas, is a stressor of concern for plants in

the risk assessments, as it demonstrates a phytohormonal mode of acti on that could have adverse

effects on plant physiology . Therefore, the stressors of concern for plants in the risk assessment

include ethephon and ethylene.

2.6.2

. Measures of Exposure

Using EFED’s standard suite of models, surface water estimated env ironmental concentrations

(EECs) were generated for ethephon for the registered uses. The Surface Water Concentration

Calculator (SWCC, v 1.106, May, 2014) is used to generate estimated environmental

concentrations (EEC)s that may occur in surface water. The SWCC simulates pesticide transport

via runoff from an agricultural field (in addition to loadings from spray drift), following

applications to crops . The model then simulates resulting concentrations in an adjacent surface

water body ( i.e ., the stand ard pond). The measure of exposure for aquatic species in surface

water bodies receiving runoff and/or spray drift is a return frequency of 1

- in

- 10 years of the

EEC, based on 30

- year simulations. The maximum 1

- in

- 10 year return frequency concentration

is used for estimating acute exposures to aquatic organisms (plants and animals); the 1

- in

- 10 year

21

- day mean concentration is used for assessing aquatic invertebrate chronic exposure; and the

1

- in

- 10 year 60

- day mean concentration is used for assessing chr onic exposure for fish (and

aquatic

- phase amphibians for which freshwater fish serve as surrogates). EECs for ethephon

include only the parent compound as the single residue of concern. Additional details on the

model can be found at http://www.epa.gov/oppefed1/models/water/



### .

Terrestrial wildlife are potentially exposed to ethephon via consumption of residues on food

items from spray applications on various use sites . For spray applications, the T

- REX model

( T errestrial R esidue EX posure model; v. 1.5.2; June 6, 2013) is used to predict dietary exposure

to ethephon residues on foliar surfaces and insects using the Kenaga nomogram as modified by

Fletcher (Fl etcher et al. , 1994; Hoerger and Kenaga, 1972) . In this assessment, the default foliar

dissipation half

- life of 35 days was used for terrestrial modeling purposes. Additionally, the

influence of lower foliar dissipation half

- live values on risk was expl ored. Estimated exposures

of terrestrial insects to ethephon are evaluated. Additional details on the model may be found at

http://www.epa.gov/oppefed1/models/te rrestrial/trex/trex_v1_5_webversion.xlsm

.

The TERRPLANT (v. 1.2.2; October 29, 2009) model is used to derive EECs relevant to

terrestrial and wetland plants for the registered uses of ethephon . The model assumes that- Page 13 of 87

-



### default fractions of the intended ap plication will be transported to an adjacent field through

runoff and spray drift. Measures of exposure to terrestrial plants are expressed as a fraction of

the mass of the ethephon applied to a treated field. Additional details on the model may be

found at http://www.epa.gov/oppefed1/models/terrestrial/index.htm#terrplant



### .

To characte rize potential non

- target animal and plant exposure from spray drift alone, Tier 1

m odules in AgDRIFT (v. 2.1.1, December 2011) were used to estimate how far off

- site spray

drift exposure might occur at a level kn own to cause adverse effects based on aquatic and

terrestrial toxicity endpoints

. Additional details on the model may be found at

http://www.agdrift.com/AgDRIFt2/DownloadAgDrift2_0.htm



### .

The Screening Tool for Inhalation Risk (STIR v.1.0, November 19, 2010) was used to calculate

an upper

- bound estimate of wild life inhalation exposure using ethephon ’s vapor pressure and

molecular weight for vapor phase exposure as well as the maximum application rate and method

of application for spray drift. STIR incorporates results from several toxicity studies including

acu te oral and inhalation rat toxicity endpoints obtained from the “six

- pack” of core studies,

which is a series of six guideline studies that are submitted to the Registration Division of the

Office of Pesticide Programs for technical and formulated products of a pesticide (LD 50 

### = 1205

mg/kg

- bw/day, MRID 00029509 ; and inhalation LC 50 

### > 2.13 mg/L, MRID 43849403

, respectively) as well as the most sensitive acute oral avian toxicity endpoint ( Bobwhite quail ;

Colinus virginianus ; LD 50 

### = 596 mg/kg

- bw, MRID 00027493 ) . Based on the results of the STIR

model (- Page 14 of 87

-



### Appendix D ), exposure through inhalation of spray drift or the vapor phase of ethephon is not

considered a primary pathway of concern for either avian or mammalian species on an acute

inhalation exposure basis. Additional details on the model may be found at

http://www.epa.gov/oppefed1/models/terrestrial/

.

The analysis of the inhalation route in STIR does n ot consider that aggregation with other

exposure pathways such as dietary, dermal, or drinking water may contribute to a total exposure

that has a potential for effects to non

- target animals. However, the Agency does consider the

relative importance of ot her routes of exposure in situations where data indicate that pesticide

exposures through other routes may be potentially significant contributors to wildlife risk

(USEPA, 2004a)

. The risk characterization section ( Section 4.3 ), discusses the impact of

consideration of other routes of exposure that have been identified as potentially important and

the degree of certainty associated with screening

- level ri sk assessment conclusions. Detailed

information about STIR v.1.0, as well as the tool, can be found on EPA’s website

( http://www.epa.gov/pesticides/science/models_pg.htm#t errestrial ).

The Screening Imbibition Program (SIP v.1.0, released June 15, 2010) was used to calculate an

upper

- bound estimate of wildlife drinking water exposure using ethephon ’s solubility ( i.e

., 1.24 x

10 6 

### mg/L at 23 o 

### C, MRID 41154506 ), and compared t o the most sensitive acute and chronic avian

and mammalian toxicity endpoints (see Table 11 7 ). Based on this analysis, d rinking water

exposure alone is considered a potential pathway of concern for birds or mammals on either an

acute or chronic exposure basis. For a sample of the output generated by SIP v.1.0, please see- Page 15 of 87

-



### Appendix E

. Additional details on the model may be found at

http://www.epa.gov/oppefed1/models/terrestrial/

.

Ethephon is reported to have a very low octanol/water partition coefficient (K ow <0.00626;

MRID 41743501 

### ), therefore, it is not expected to accumulate in fish.

2.6.3

. Measures of Eff

ect

Measures of effect are obtained from a suite of registrant

- submitted guideline studies that were

conducted with a limited number of surrogate test species ( Table 3 ). The test species ar e not

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

ability to thrive under laboratory conditions. Toxicity testing reported in this risk assessment

utilizes surrogate species to represent all freshwater fish (2000+) and bird (680+) species in the

U.S. In addition, the ECOTOX database was searched twice; once in 2009 by USEPA’s Office

of Research and Development Mid

- Continent Ecology Division (ORD

- MED), and once in 2015

using the ECOTOX website; to provide more ecological effects data for ethephon

. The 2009

ECOTOX run was reviewed in 2010 for the ethephon Problem Formulation. Data were further

examined if endpoints were more sensitive (lower) than endpoints available from submitt ed

studies or were available for amphibians, freshwater mollus c s, or reptiles (USEPA, 2011) . Data

meeting the OPP’s standard for inclusion in risk assessment

( http://www.epa.gov/pesticides/science/literature

- studies.html ) were available at the time of the

2009 ECOTOX run that showed greater sensitivity than results from submitted studies for

aquatic nonvascular plants (M a et al

, 2004, ECOTOX Number E095681 )

.

The acute measures of effect used in this screening

- level assessment are the LD 50 

### (Lethal Dose),

LC 50 

### (Lethal Concentration), EC 50 

### (Effects Concentration), and IC 50 

### (Inhibition Concentration).

These are measures of acute toxicity which result in 50% of the respective effect in tested

organisms. The endpoints for chronic measures of exposure are the NOAEC (No Observed

Adverse Effects Concentration) and the NOAEL (No Observed Adverse Effects Level).

Toxicity studies were submitted for freshwater fish and invertebrates, estuarine/marine fish and

invertebrates, aquatic and terrestrial plants, bi rds, mammals, and honey bees. The endpoints

used for risk characterization were derived from studies which underwent review and were

classified as “acceptable” (conducted under guideline conditions and considered to be

scientifically valid) or “supplement al” (conditions deviated from guidelines but the results are

considered to be scientifically valid).

Table 3 lists the measures of environmental exposure and ecological effects used to assess the

potential risks of ethephon to n on

- target organisms. The methods used to assess the risk are

consistent with those outlined in the document “ Overview of the Ecological Risk Assessment

Process in the Office of Pesticide Programs ” (USEPA, 2004a)

.- Page 16 of 8 7

-



### Table 3

. Measures of Exposure and Effect Used in Assessing Potential Risks Associated with

the Proposed Uses of E thephon

.

Assessment Endpoint Surrogate Species and Measures of

Ecological Effect 1 Measures of Exposure

Birds 2 Survival Lowest acute LD 50 (single oral dose test)

and LC 50 (subacute dietary test)

Upper

- bound residues on

food items Reproduction

and Growth Lowest NOAEC

(21

- week reproduction test)

Ma mmals Survival Lowest acute LD 50 (single oral dose test)

and LC 50 (subacute dietary test)

Reproduction

and Growth Lowest NOAEC

(2

- generation reproduction test)

Aquatic Animals (Fish and

invertebrates) 3 Survival Lowest tested LC 50 or EC 50 (acute toxici ty test) Peak EECs 4

Reproduction

and Growth Lo west NOAEC (early life

- stage, full

life

- cycle tests , 10

- day sediment tests,

or chronic sediment tests) 21

- day EECs for invertebrates

and 60

- day EECs for fish 4

Terrestrial plants 5 Survival and

growth Lowest E C 25 (for non

- listed plants) and

corresponding NOAEC (for listed

plants)

(endpoints derived for monocots and

dicots from seedling emergence and

vegetative vigor studies) Estimates of runoff and spray

drift to non

- target areas

Insects 6

Survival Lowest hon ey bee LD 50 (acute contact

test) Upper

- bound residues on tall

grass 7

Aquatic plants (vascular

and non

- vascular) Survival and

growth Lowest EC 50 (for non

- listed plants) and

corresponding NOAEC or EC 05 (for

listed plants) Peak EECs 4

1 The most sensitive s pecies tested within taxonomic groups is used for screening

- level risk assessments.

2 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

3 Freshwater fish represent surrogates for aquatic

- phase amphibians.

4 Aquatic EECs are based on modeling described in Section 3.2.2.1

.

5 Four species of two families of monocots

- one is corn, six species of at least four dicot families, of which one is

soybeans.

6 Risk to terrestrial invertebrates from ethephon use is quantitatively evaluated agai nst the acute listed terrestrial

invertebrate LOC of 0.4.

7 The tall grass residue value from the T

‐ REX model (v. 1.5.2) is used as a surrogate for pesticide concentrations in

nectar and pollen.



### 2.6.4

. Integration of Exposure and Effects

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

ecological effec ts on non

- target species. For the risk assessment of ethephon , the risk quotient

(RQ) method is used to compare estimated exposure and measured toxicity values. The RQ

method involves dividing estimated environmental concentrations (EEC) by acute and chr onic

toxicity values. The resulting RQs are then compared to the Agency’s Levels of Concern (LOC)

(USEPA, 2004a) ( Table 4 ). The LOCs are used to indicate when applications of ethephon , as- Page 17 of 87

-



### directed on the label, have the potential to cause adverse e ffects to non

- target organisms from

exposure to ethephon

.

Table 4 . Agency Risk Quotient (RQ) Met rics and Levels of Concern (LOC) Per Risk Class.

R isk C lass R isk D escription RQ LOC

Aquatic Animals (fish and invertebrates)

Acute Potential for effects to non

- listed animals from acute

exposures Peak EEC/LC 50 1 0.5

Acute

Restricted Use Potential for eff ects to animals from acute exposures

Risks may be mitigated through restricted use

classification Peak EEC/LC 50 1 0.1

Acute Listed

Species Listed species may be potentially affected by acute

exposures Peak EEC/LC 50 1 0.05

Chronic Potential for effects to n on

- listed and listed animals

from chronic exposures 60

- day EEC/NOAEC (fish)

1 21

- day EEC/NOAEC

(invertebrates)

Aquatic Plants

Non

- Listed Potential for effects to non

- listed plants from

exposures Peak EEC/LC 50 1 1

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

Terrestrial Animals (mammals and birds) 2

Acute Potential for effects to non

- listed animals from acute

exposures EEC/LC 50 (Dietary)

0.5

EEC/LD 50 (Dose)

Acute

Restricted Use Potential for effects to animals fro m acute exposures

Risks may be mitigated through restricted use

classification EEC/LC 50 (Dietary)

0.2

EEC/LD 50 (Dose)

Acute Listed

Species Listed species may be potentially affected by acute

exposures EEC/LC 50 (Dietary)

0.1

EEC/LD 50 (Dose)

Chroni c Potential for effects to non

- listed and listed animals

from chronic exposures EEC/NOAEC 1

Honey bee s

Acute Potential for effects to individual bees or brood due

to contact and dietary exposure. Contact EEC/acute contact

LD 50

Diet EEC/ acute oral LD 50

Diet EEC/ Larval LD 50 0.4

Chronic Potential for effects to individual bees or brood due

to contact and dietary exposure. Diet EEC/ adult NOAEL

Diet EEC/ larval NOAEL 1.0

Terrestrial and Semi

- Aquatic Plants

Non

- Listed Potential for effects to non

- target, non

- listed plants

from exposures EEC/ EC 25 1

Listed Plant Potential for effects to non

- target, listed plants from

exposures EEC/ NOAEC

1

EEC/ EC 05

1 LC 50 or EC 50

.

2 EEC based on upper bound Kenaga nomogram values for foliar exposure.- Page 18 of 87

-



### 3. Anal ysis

3.1

. Use Characterization

Use patterns

Ethephon was first registered in the United States in 1973. Ethephon is a plant growth regulator

used on field crops (e.g., blueberries, cotton, cucumbers, and wheat), fruit and nut orchards,

vineyards, orna mentals and turf (e.g., golf courses and residential lawns ) . Currently, there are 43

active product registrations for ethephon. These formulations are flowable liquids or emulsifiable

concentrates.

Applications are made by ground or air spray. Maximum sin gle application rates for ethephon,

numbers of applications per year, application intervals and application methods for all registered

uses are provided in Table 5

.

Table 5 . Ethephon Application Rates for the Various Uses.

Use S ingle max

application

rate (lb a.i./A) Number of

app. per year Application

interval (d) max annual

application

rate

(lb a.i./A) Application method(s)

Barley 0.5 1 Not stated 0.5 Ground, ae r ial

Blackberry 2 1 Not stated 2 Ground, aerial

Blueberry 2 1 No t stated 2 Ground, aerial

Blueberry (SLN) 0.43 2 21 Not stated Ground, aerial

Cantaloupe 0.75 1 Not stated 0.75 Ground, aerial

Coffee (SLN) * 0.5 Not stated Not stated Not stated Not stated

Cotton 2 1 Not stated 2 Ground, aerial

Cucumber (CA) 0.25 6 3 Not stated Ground, aerial

Cucumber (outside

CA) 0.083 Not stated 7 Not stated Ground, aerial

Grass for seed 1 1 Not stated Not stated Ground, aerial

Pepper 1 1 Not stated 1 Ground, aerial

Pineapple 2 2 ** Not stated 3 Ground, aerial

Pumpkin 0. 25 6 3 1.5 Ground, aerial

Squash 0.25 6 3 1.5 Ground, aerial

Sugarcane 0.5 1 Not stated 0.5 Aerial

Tobacco 2 1 Not stated 2 Ground, aerial

Tomato 1.63 1 Not stated 1.63 Ground, aerial

Tomato (large

- fruited

greenhouse variety;

SLN) 1.25 Not stated N ot stated Not stated Ground

Wheat 0.5 1 Not stated 0.5 Ground, aerial

Apples 2 1 Not stated 2 Ground, aerial

Pears (SLN) 1 1 Not stated Ground

Cherries 1 1 Not stated 1 Ground, aerial

Douglas firs (seed

orchards; SLN) 3.3 Not stated Not stated N ot stated Ground, aerial- Page 19 of 87

-

Grapes 0.5 1 Not stated 0.5 Ground, aerial

Macadamia nut (SLN) 1.44 1 Not stated Not stated Ground, aerial

Walnut 1.25 1 Not stated 1.25 Ground, aerial

Ornamental conifers 0.5 Not stated Not stated Not stated Ground, aerial

Ornamental deciduous

fruit trees 1 Not stated Not stated Not stated Ground, aerial

Ornamental Douglas

fir 0.25 Not stated Not stated Not stated Ground, aerial

Ornamental

herbaceous plants 5.28 Not stated 14 Not stated Ground

Ornamental trees 0.19 per 20

gallon 1 Not stated 0.19 per 20

gallon Ground, ae r ial

Plumeria (SLN) 0.013 (lbs

a.i./tree) 1 Not stated Not stated Ground

Commercial lawns

and golf courses † 4.1 Not stated 28 Not stated Ground

Recreational lawn s 3.4 6 28 Not stated Ground

Bol d text indicates the use with the highest annual application rate

*: Allowed in Puerto Rico only

**: Plus an additional application of 1 lb a.i./A

† : Max application rate



### According to the 2014 Screening Level Usage Analysis (SLUA) prepared by the Biological and

Economic Analysis Division (BEAD) using data from 200 4

- 201 2 , the average percent crop

treated for cotton is estimated to be 55% nationally, with a maximum estimate of 70% (USE PA,

2012) . The average annual pounds applied for cotton estimated in the SLUA was 8, 4 00,000

pounds per year. Use sites with the next highest usage after cotton are apples, tomatoes, and

grapes, but the overall pounds applied to those use sites is much l ower (30,000; 30,000; and

20,000 pounds annually respectively).

As shown in Figure 1

, based on USGS National Water Quality Assessment Program (NAWQA)

from 2012, ethephon agricultural us age appear s to be predominat ely on cotton. NAWQA does

not consider non

- agricultural uses of ethephon in its data collection

. Neither does BEAD include

non

- agricultural uses in the SLUA.- Page 20 of 87

-



### Figure 1 . Reported Ethephon Use f rom USGS NAWQA D atabase

http://water.usgs.gov/nawqa/pnsp/usage/maps/show_map.php?year=2011&map=ETHEPHON&hilo=L&disp=Ethephon

(accessed July 14, 2015).- Page 21 of 87

-



### 3.2. 3.2. Exposure Characterization

3.2.1. Environmental Fate and Transport Characterization

The general physical/chemical properties of ethephon are summarized in Table 6 . Environmental

fate and transport

- related properties of eth ephon are characterized in further detail in the

following sections.

Table 6 . General Physical and Chemical Properties of Ethephon.

Parameter Value Reference

Physical/Chemical Parameters

Molecular mass 144.5 g/mol USEPA, 1995

Vapor pressure (25°C) <1.0 x 10

- 7 

### torr MRID 41154506

Water solubility (23°C, pH not reported) 1.24 x 10 6 

### mg/L MRID 41154506

Dissociation constants (25°C) 2.5 (pKa 1 

### ); 7.2 (pKa 2 

### ) MRID 41154506

Octanol

- water partition coefficient (K OW 

### )

(25°C, pH not repor ted) < 6.3 x 10

- 3 

### MRID 41743501



### Table 7 contains the submitted environmental fate data for the pesticide

.

Table 7 . Environmental Fate Data Summary for Ethephon.

Mobility

Freundlich adsor ption Coefficient (k d 

### ) 30 L/kg (5 soils; range:

2.37

- 57.3 L/kg ) MRID

42126001

Persistence in Water

Hydrolysis half

- life (25°C) 74 d (pH 5)

2.4 d (pH 7)

1.0 d (pH 9) MRID

41545701

Aqueous photolysis half

- life (25°C) 139 d MRID

41545601

Aerobic aquatic metabolism half

- life (25°C) 2.6 d MRID

4820200 3

Anaerobic aquatic metabolism half

- life (25°C) 5.3 d MRID

41757702

Persistence in Soil

Soil photolysis half

- life (25°C) 12 d (sandy loam, pH 6.1, OM 1.1%) MRID

41681401

Aerobic soil metabolism half

- life ( 25°C) 9.1 d (sandy loam, pH 6.1, OM 1.1%)

11 d (clay loam soil, pH 7.6, OM 4.8%) MRID

41757701

, 48202001

Field Dissipation

Terrestrial field dissipation half

- life; maximum

leaching depth 6.8 d; 15 cm (NC; pH 6.6)

12 d; 45 cm (CA; pH 7.8)

25 d; 60 cm (WA ; pH 7.1) MRID

42011501- Page 22 of 87

- 

### 3.2.1.1. Transport and Mobility

Ethephon (2

- chloroethylphosphonic acid) is a white, waxy solid (MRID 41154506) and will not

likely volatized as indicated by a low partial vapor pressure of <1 x 10

- 7 

### torr (25°C; MRID

41154506). The compound is an anion (pKa 1 

### = 2.5) in acidic and neutral environments and a

double anion in alkaline environments (pKa 2 

### = 7.2). Ethephon is present as an anion in most

environmentally relevant conditions. As an anion, ethephon is soluble in water up to 1.24 x 10 6



### mg/L at 23°C (pH not reported; MRID 41154506). Also, ethephon will not bioaccumulate in

aquatic or terrestrial food chains, which is supported by its low octanol

- to

- water partitioning

coefficient (K OW 

### ) of ≤6.3 x 10

- 3 

### (MRID 41743501).

E theph on showed high variability in adsorption to five studied acidic soils (initial soil pH values

of 4.6

- 6.0), ranging from moderately to slightly mobile in soil (K FOC 

### range of 386

– 3070 L/kg OC 

### ;

1/n ra nge of 0.98

– 1.02; MRID 42126001 ), according to the FAO soil mobility classification

scheme (USEPA, 2006 d ). The mechanisms behind this variability are not well understood;

however, adsorption to organic matter appears to account for some of the variability, as the

coefficient of variation for the Freundlich organic carbon

- normalized soil partition coefficients

(K FOC 

### ; CV = 58%) is less than that for the Freundlich soil

- water partition coefficients (K F 

### ; CV =

85%). However, regression of percents organic carbon in soil versus Freundlich soil

- water

partition coefficien ts is characterized by a correlation coefficient of 0.75 and a probability value

>0.05 (0.057), which indicates uncertainty in correlating the data. A dsorption/desorption are not

pH dependent . R egression of soil pH versus Freundlich soil

- water partition co efficients is

characterized by a correlation coefficient of 0. 1444.

3.2.1.2. Degradation

Ethephon is relatively stable to photodegradation in water, with a half

- life of 139 days (MRID

41545601); however, the compound more readily photodegrades in soil, wi th a half

- life of 12

days (MRID 41681401). Ethephon is also relatively stable to hydrolysis in acidic conditions,

with a half

- life of 74 days (MRID 41545701). However, ethephon hydrolyzes readily in neutral

and alkaline conditions, with half

- lives of 2.4 and 1.0 days, respectively.

Ethephon is susceptible to microbial degradation in aerobic soil, with a half

- li ves that range from

9 .1

– 11 days (MRID 41757701 , 48202001 ). Ethephon moderately persistent in soil according to

Goring et al., 1975 scale for pesticide degradation in soil. Susceptibility to biodegradation in

acidic, aerobic soil indicates that ethephon will degrade in acidic, aerobic water bodies; however,

if ethephon biodegradation in aerobic aquatic systems is similar to that of anaerobic aqu atic

systems, ethephon may persist in acidic, aerobic water bodies.

Major degradates of ethephon identified in environmental fate studies include ethylene,

phosphoric acid, and 2

- hydroxyethylphosphonic acid (HEPA), the latter of which is less mobile

than the parent compound. Minor identified degradates include methylated phosphoric acid and

carbon dioxide. Ethylene was quantified in submitted studies based on its conversion to carbon

dioxide. While ethephon is not expected to degrade into volatile compo unds other than ethylene- Page 23 of 87

-



### and carbon dioxide, data were not provided to confirm that ethylene and carbon dioxide were the

only volatilized degradates present in the test vessels’ headspace.

3.2.1.3. Field Studies

Ethephon dissipated with half

- lives of 7 to 25 days and showed moderate to low mobility under

actual field conditions (MRID 42011501 ), which is relatively consistent with the submitted

laboratory data. Although ethephon was detected at depths of 45 and 60 cm in the loam soil in

California and t he loamy sand soil in Washington, respectively, these detections were likely the

result of sample contamination through the use of the bucket auger sampling apparatus, given

that these detects were first encountered within 1 week after application. In Nor th Carolina sand

soil, ethephon did not move below the 15

- cm depth.

In California , ethephon dissipated with a calculated half

- life of 12 days in the 0

- to 45

- cm depth

of loam soil after spraying with Ethrel  

### (2 lbs a.i./gallon SC/L) at a nominal concentra tion of 1.6

lbs a.i./A (maximum label rate). At the time of application (May 1990), the field plot contained

tomato plants that were 10

- 30 cm in height. At 0

- to15

- cm soil depth, ethephon concentrations

ranged from 0.62

- 0.87 ppm immediately post treatmen t , 0.31

- 0.39 ppm at 4 days, 0.13

- 0.19 ppm

at 15 days, 0.06

- 0.08 ppm at 29 days, and 0.02 ppm at 98 days. In the 15

- to 30

- cm soil depth,

ethephon averaged 0.026 ppm at 4 and 9 days post treatment and ≤ 0.01 ppm at 15 through 98

days. Ethephon was detected in the 30

- to 45

- cm depth only at 4 and 9 days post treatment , at

0.010

- 0.020 ppm. Ethephon was not detected below a depth of 45 cm.

In North Carolina , ethephon dissipated with a calculated half

- lif e of 6.8 days in the 0

- to 15

- cm

depth of sand soil that was sprayed with Prep  

### (6 lbs a.i./gallon SC/L) at a nominal concentration

of 2.0 lbs a.i./A (maximum label rate). At the time of application (August 1990), the field plot

contained cotton plants tr immed to 0.2 m in height. In the 0

- to 15

- cm soil depth, ethephon was

detected at 0.72

- 1.29 ppm immediately post treatment , 0.35

- 0.41 ppm at 4 days, 0.06

- 0.11 ppm

at 16 days, and 0.03

- 0.05 ppm at 31 days. Ethephon was not detected below a depth of 15 cm.

In Washington State , ethephon dissipated with a calculated half

- life of 25 days in the 0

- to 60

- cm

depth of loamy sand soil that was sprayed with Cerone  

### (4 lbs a.i./gallon SC/L) at a nominal

concentration of 1.66 lbs a.i./A (>3x maximum label rate). At the time of application (April

1990), the field plot contained wheat plants that were 0.5

- 0.7 cm in height. In the 0

- to15

- cm

soil depth, ethephon was detected at 1.18

- 1.34 ppm immediately post treatment , 0.14

- 0.31 ppm

at 7 days, 0.10

- 0.21 ppm at 30 days , and 0.01

- 0.04 ppm at 58 through 128 days. In the 15

- to 30

- cm soil depth, ethephon averaged 0.30 ppm at 7 days post treatment and steadily decreased to

0.01 ppm at 128 days. Ethephon averaged a maximum of 0.205 ppm in the 30

- to 45

- cm depth

and 0.06 pp m in the 45

- to 60

- cm depth, both at 7 days post treatment

.

3.2.1.4. Monitoring Data

Mon itoring studies of ethephon and/ or its major degradates were not found in a literature search.

The U.S. Geological Service National Water Quality Assessment ( NAWQA) and

National Stream Quality Accounting Network (NASQAN) databases do not show instances of

ethephon or its degradates monitored in water bodies. The California Department of Pesticide- Page 24 of 87

-



### Re gulation Surface Water Database does not contain instances of ethephon or its degradates.

Ethephon is not a regulated chemical under the Safe Water Drinking Act or related statutes.

Therefore, it is not listed in the EPA Safe Drinking Wat er Information System database nor is it

found in the EPA Unregulated Contaminants Monit oring Regulation chemical monitoring

database. Groundwater monitoring studies from 1971 to 1991 listed in th e EPA Pesticides in

Ground Water Database (Environmental Protection Agency, 1992) did not test for ethephon.

3.2.1.5. Bioconcentration Data

Fish bioconcentration data are not necessary for compounds with low K

ow 

### , but data have been

submitted for ethephon ( MRID 00136290 ; in review)

.

3.2.1.5. Environmental Degradates

Table 8 lists the maximum degradate amounts measured in degradation studies.

Tabl e 8 . Ethephon and i ts Major Radiolabeled Degradates (amounts >10% in bold).

Common

Name Chemical Name Chemical Structure Study Type Maximum

%AR A (day)

Parent

Ethephon 2

- chloroethylphosphonic

acid -- --

Major Radiolabeled (>10%) Degradates

Ethylene ethene Hydrolysis (pH 5) 23 (30 d)

Hydrolysis (pH 7) 81 (7 d)

Hydrolysis (pH 9) 71 (2 d)

Soil Photolysis 53 (30 d)

Aerobic Soil Metabolism 15 (21 d)

Anaerobic Aquatic Metabolism 52 (14

- 30 d)

HEPA 2

- hydroxyethylphosphonic

acid Hydrolysis (pH 5) Not detected

Hydrolysis (pH 7) Not detected

Hydrolysis (pH 9) Not detected

Soil Photolysis 20 (10

- 30 d)

Aerobic Soil Metabolism 64 (30 d)

Anaerobic Aquatic Met abolism 43 (30 d)

Unextracted

residue -- -- Hydrolysis (pH 5) Not detected

Hydrolysis (pH 7) Not detected

Hydrolysis (pH 9) Not detected

Soil Photolysis 

### 23 (30 d)

Aerobic Soil Metabolism 

### 15 (30 d)

Anaerobic Aquatic Metabolism 

### 7.7 (30 d )

A. %AR means “percent of applied radioactivity”.- Page 25 of 87

-



### Ethylene (as a gas; CAS No. 74

- 85

- 1) was the primary degradate in both the photolysis and

hydrolysis studies. The SRC PhysProp data base (accessed Mar. 3, 2010) reports the

experimentally

- derived physical

- chemical properties of ethylene listed in Table 9

.

TABLE 9

. General Chemical Properties of Ethylene.

Parameter Value Reference

Molecular mass 28.05 g/mol (Calculated)

Vapor pressu re (25°C) 5.21 x 10 4 

### torr Daubert & Danner, 1985

Water solubility (25°C) 131 mg/L McAuliffe, 1966

Henry’s law constant (25°C) 0.228 atm

- m 3 

### /mol Wasik and Tsang, 1970

Octanol

- water partition coefficient (K OW 

### )

(temperature not reported) 13 Hansch et al. , 1 995



### The experimental Henry’s law constant of 0.228 atm

- m 3 

### /mol at 25°C is two orders of magnitude

less than the value calculated from vapor pressure and solubility in water at the same temperature

( i.e. , 14.7 atm

- m 3 

### /mol). Even with the lower Henry’s law constant, and with a vapor pressure of

5.2 x 10 4 

### torr at 25°C, most ethylene produced from ethephon in terrestrial or aquatic

environments will partition into the air. The Level III fugacity model in EpiSUITE (v4.0)

estimates a half

- life in air of 25 hour s, which is driven by reaction with hydroxyl radicals.

The major degradate in the aerobic soil metabolism study, HEPA, was soil

- bound, not easily

extracted, and possibly persistent, as the concentration of HEPA increased across the length of

the 30

- day st udy. The mobility of HEPA was confirmed in a batch equilibrium study as slightly

to hardly mobile (K fOC 

### range of 1460

– 12100 L/kg OC 

### ; 1/n range of 0.89

– 0.98; MRID 43991301),

according to the FAO soil mobility classification scheme (USEPA, 2006 d ). Data from

supplemental aerobic soil studies (MRID # 48202001

- 2) and soil photolysis study (MRID#

41681401) showed u nextracted residues represented >10% of applied radioactivity was likely to

be ethephon parent or HEPA. The anaerobic aquatic metabolism study’s majo r degradates

included both ethylene gas and HEPA. Ethylene gas is the biologically active degradate of

ethephon.

3.2.2. Measures of Aquatic Exposure

3.2.2.1. Surface Water Exposure to Ethephon

Using EFED’s standard suite of models, surface wa ter EECs were generated for ethephon for the

registered use s on various crops . The Surface Water Concentration Calculator (SWCC, v 1.106,

May, 2014), which incorporates the Pesticide Root Zone Model (PRZM) and the Exposure

Analysis Model System (EXAMS), is used to generate EECs that may occur in surface water.

The SWCC simulates pesticide transformation on and runoff from an agricultural field (in

addition to loadings from spray drift), following applications to crops. The model then simulates

resulting concentra tions in an adjacent surface water body. The EXAMS model simulates- Page 26 of 87

-



### pesticide concentrations in water due to loading via runoff, erosion, and spray drift, assuming a

standard 1

- ha pond, 2

- m deep (20,000 m 3 

### ) with no outlet that borders a 10

- ha treated field

. Simulations are for 30 years, from which the Agency estimates peak values that are expected to

recur on average once every ten years, based on time series of daily estimated concentrations.

The coupled PRZM and EXAMS models and user’s manuals are avail able from the U.S.

Environmental Protection Agency Water Models web

- page

(http://www.epa.gov/oppefed1/models/water).

Exposure estimates generated using the standard pond are intended as surrogates for potential

concentrations in a wide variety of vulnerab le water bodies, including prairie potholes, playa

lakes, vernal pools, other wetlands, man

- made and natural ponds, and ephemeral and first

- order

streams. Multiple site

- specific factors will tend to make such water bodies more or less

vulnerable than the standard pond. Static water bodies that have larger ratios of pesticide

- treated

drainage area to water body volume are generally expected to have higher peak concentrations

than the standard pond’s EECs. Such water bodies may be smaller in size, and/or h ave larger

drainage areas. However such water bodies may be more likely to overflow and discharge

pesticide in their effluent, whereas the EFED standard pond has no discharge. As watershed size

increases, it becomes increasingly unlikely that the entire watershed is planted with a single crop

that is all treated simultaneously with a pesticide. Headwater streams may have peak

concentrations that are higher than those predicted for the standard pond, but such concentrations

will likely persist for only sh ort periods of time or distance, as they are carried downstream and

diluted with water originating elsewhere.

The general chemical and environmental fate data for ethephon listed in Table 7 & Table 7 were

used for generating model input parameter values for SWCC ( Table 1 1 ). C hemical specific and

model input values were chosen in accordance with current divisional guidance (USEPA, 2009).

Modeling was conducted to generate EECs in surface water of ethephon using SWCC.

Modeling results are reported in Table 1 2

.

Table 1 0 . Registered Uses Modeled for E thephon

Crop Application

method Registration (application timing) Max single

application

rate (lb

a.i./A) Max

seasonal

a pplication

rate (lb

a.i./A) Minimum

retreatment

interval (days)

Cotton Ground,

Aerial At mature "cut

- out" stage 2 2 N A

Tobacco Ground Mature leaves, not overly rank green 2 2 N A

Apples Ground,

Aerial 2

- 4 weeks after full bloom 2 2 N A

Berries Ground,

Ae rial Apply when barren berries are between

90% and 100% petal fall 2 2 N A

Cherries Ground Varies with plant variety 1 1 N A

Grapes Ground,

Aerial 5

- 30% berry showing color 0.5 0.5 N A

Peppers Ground,

Aerial 10

- 30% red and chocolate fruit 1 1 N A

Pineapple Ground, "bearing age", 12 months after planting 2 2 N A- Page 27 of 87

- Aerial and 6 months prior to harvest

Sugar cane Aerial Just prior to flower formation 1 1 N A

Tomatoes Ground,

Aerial 5

- 30% of fruit are pink 1.63 1.63 N A

Tomatoes (Processing) Ground 5

- 30% of fruit are pink 1.63 1.63 N A

Tomatoes

- Fresh

Market (CA only) Ground 3

- 6 days prior to harvest 1.25 1.25 N A

Walnuts Ground,

Aerial 95

- 100% of nuts are mature size 1.25 1.25 N A

Wheat and Barley Ground,

Aerial Growth stage Feekes 8 to 10 and

Zadok’s Code 37

- 45 0.5 0.5 N A

Ornamentals Ground Varies with plant variety 2.8 2.8 7

- 14

Turf ** Ground Actively growing turf; Prior to seed head

formation (poa annua) 4 20 14

Pumpkin (Hybrid seed

production only)

(IL only Ground 2

- 4 Leaf stage 0. 25 1.5 7

Cantaloupes (TX only) Ground,

Aerial 2

- 5 days prior to harvest 0.75 0.75 NA

Cucumber, Pumpkins,

and squash (Hybrid

seed production only)

(CA only) Ground First true leaf stage 0.25 1.5 3

NA : Not Available.

*: Maxi mum application rate registered.



### Table 1 1

. SWCC Chemical Specific Input Parameter Values for Modeling Ethephon Use.

Input Parameter Value S ource C omment

Application Rate in lbs a.i./A See Table 1 0

Application Method See Table 1 0

Molecular Mass (g /mol) 144.5 MRID 46255403

Spray Drift Fraction 1 2 .5 (aerial

default)

6.2 (Ground

default) 

### Guidance on Modeling Offsite

Deposition of Pesticides via Spray Drift

for Ecological and Drinking Water

Assessments. 2013

Application Efficiency 0.99 (ground)

0.9 5 (aerial)

Vapor Pressure (Torr) 1.00E

- 7 MRID 41154506

Solubility in Water at 25°C (mg/L) 1.2E+ 6

(essentially

completely

miscible with

water) MRID 41154506

Freundlich adsorption Coefficient (K d 

### )

(L/kg) 30 MRID 42126001 Represents the mean K D 

### , of five soils.

Binding is not correlated with organic

carbon content

. Aerobic Soil Metabolism Half

- life

(days) 13 MRID 41757701,

48202001 The 90 th 

### percentile confidence bound on

the mean half

- life value (9.11, and 11

days) . T he input guidance (2009)

.



### Aerobic A quatic Metabolism Half

- life

(days) 2.6 MRID 48202003 The 90 th 

### percentile confidence bound on

the mean half

- life value (2.5, and 2. 4- Page 28 of 87

- 

### days) . T he input guidance (2009)

.



### Anaerobic Aquatic Metabolism Half

life (days) 16 MRID 41757702 Represents 3x the non

- line ar half

- life of

5.3 days.

Hydrolysis Half

- life (days) 2.4 (pH 7) MRID 41545701

Aqueous Photolysis

- Half

- life (days) 1 39 MRID 41545601



### Table 1 2

. Surface Water Modeling Results for Ethephon on Various Crops.

Aquatic Surface Water Modeling Results

Crop Group SWCC Model

Scenario 1

- in

- 10 year Surface Water (μg/L)

peak daily peak 21

- day

average peak 60

- day

average

Berries OR berries 14.0 1.49 0.53

Cucurbits FL cucumber 4.28 0.96 0.41

Field crops &

Tropical fruit MS cotton

FL sugarcane

NC tobacco 14.3

3.59

7.25 2.25

0.58

1.14 0.92

0.26

0.45

Fruiting vegetables FL tomato

PA tomato

CA tomato 23.0 *

13.2

11.5 3.07

2.20

1.79 1.08

0.80

0.63

Grasses FL turf

ND wheat 17.7

3.49 4.00 *

0.58 3.00 *

0.21

Grapes NY grape 4.01 0.70 0.26

Nuts OR filbert

GA Pe cans

CA Almond 8.73

11.0

9.40 0.94

1.70

0.93 0.33

0.60

0.33

Ornamentals FL nursery

NJ nursery

CA nursery 16.0

14.2

9.72 2.13

2.11

0.95 0.84

0.86

0.34

Pome fruit NC apples 14.0 2.22 0.83

Stone fruit MI cherries 4.14 0.74 0.30

Bold text and asterisk( * ) denote t he highest EEC



### Selected model input and output files supporting these values are presented in Appendix A

.

3.2. 3

. Measures of Terrestrial Exposure

3.2.3.1

. Ingestion of Surface Residues by Birds and Mammals

Terrestrial wildlife exposure est imates are typically calculated for birds and mammals,

emphasizing a dietary exposure route for uptake of pesticide active ingredients. Avian exposures

are considered surrogates for exposures to terrestrial

- phase amphibians and reptiles. For

exposure to te rrestrial organisms, such as birds and mammals, pesticide residues on food items

are estimated, based on the assumption that organisms are exposed to pesticide residues in a

given exposure use pattern. For ethephon , application methods for the registered uses include- Page 29 of 87

-



### foliar spray . For terrestrial animals, the T

- REX model (Version 1.5.2) 2 

### is used to calculate

dietary

- and dose

- based EECs of ethephon for mammals and birds feeding on the site of

application. Input values for T

- REX include the maximum single application rates, number of

applications, and retreatment interval for a given use and are located in Table 1 0

. In this

assessment, EFED uses a default foliar dissipation half

- life of 35 days as an input for terrestrial

exposure modeling in T

- REX. Addi tionally, foliar dissipation half

- life values between 1 and 35

days were explored as inputs for terrestrial exposure modeling in T

- REX.

Upper

- bound Ken a ga nomogram values based on Hoerger and Kena ga (19 72) as modified by

Fletcher et al

. (1994) are used to derive EECs for ethephon exposures to terrestrial mammals and

birds based on dietary

- and dose

- based exposures from foliar applications of ethephon ( Table

1 3 )

. A one

- year time period is simu lated. Consideration is given to different types of feeding

strategies for mammals and birds, including herbivores, insectivores and granivores. For dose

based exposures, three weight classes of mammals (15, 35, and 1000 g) and birds (20, 100, and

1000 g ) are considered. For more information on estimating exposure to terrestrial organisms,

see the T

- REX User’s Guide 3



### . EECs derived based on mean Kenaga nomogram values were

also selectively evaluated.

2 http://www.epa.gov/oppefed1/models/terrestrial/

3 http://www.epa.gov/oppefed1/models/terrestrial/trex/t_rex_user_guide.htm- Page 30 of 87

-



### Table 1 3

. T

- REX Calculated EECs as Food Residues for Terrestrial Animals from Ethephon Uses.

Food Type Dietary

- Based

EEC (mg/kg

diet) Dose

- Based EEC (mg/kg

- body weight)

Mammals and

Birds Birds Mammals

All Size s

Classes Small (20 g) Medium (100 g) Large

(1000 g) Small

(15 g) Medium

(35 g) Large

(1000 g )

Max Label Rate for Cotton , Tobacco, Apples, Berries, and Pineapple : 2 lbs a.i./A, 1 application

Short grass 480 54 7 31 2 1 40 45 8 316 73.3

Tall grass 220 25 1 14 3 6 4 2 10 14 5 33.6

Broadleaf plants/small insects 270 30 8 17 5 78.5 257 17 8 41. 3

Fruits/pods/ (seeds, dietary only) 30 34. 2 19. 5 8.72 28.6 19. 8 4.58

Arthropods 188 214 122 54. 7 179 12 4 28.7

Seeds (granivore) N/A 7.59 4.33 1.94 6.36 4.39 1.02

Max Label Rate for Tomatoes (including tomatoes for processing) : 1.63 lbs a.i./A, 1 application

Short gr ass 391.20 44 6 254 11 4 37 3 25 8 59. 8

Tall grass 179.30 204 11 7 52.1 17 1 118 27. 4

Broadleaf plants/small insects 220.05 25 1 14 3 6 4 2 10 145 33.6

Fruits/pods/(seeds, dietary only) 24.45 27. 9 15. 9 7.11 23.3 16.1 3.74

Arthropods 153.22 17 5 99.5 44.5 146 10 1 23.4

Seeds (granivore) N/A 6.19 3.53 1.58 5.18 3.58 0.83

Max Label Rate Used on Tomatoes

- Fresh Market (CA only) and Walnuts : 1.25 lbs a.i./A, 1 application

Short grass 300 34 2 19 5 87.2 286 19 8 45.8

Tall grass 137 15 7 89.3 40.0 131 90.6 21

Broadleaf plants/small insects 169 192 110 49. 1 16 1 111 2 5.8

Fruits/pods/(seeds, dietary only) 18. 8 21. 4 12. 2 5.45 17. 9 12. 4 2.86

Arthropods 11 8 13 4 7 6.3 34.2 112 7 7.4 1 8

Seeds (granivore) N/A 4.75 2.71 1.21 3.97 2.75 0.64

Max Label Rate for Peppers, Cherries, a nd Sugarcane : 1 lb a.i./A, 1 application

Short grass 240 273 15 6 69. 8 22 9 158 36. 7

Tall grass 110 125 71.4 3 2 105 72. 5 16.8

Broadleaf plants/small insects 135 15 4 87. 7 39 12 9 8 9 2 0.6

Fruits/pods/(seeds, dietary only) 15 17. 1 9.74 4.36 14.3 9.88 2.29

A rthropods 94 107 6 1.1 27.3 8 9.6 61.9 14.4

Seeds (granivore) N/A 3.80 2.16 0.97 3.18 2.20 0.51

Max Label Rate for Cantaloupes (TX only) : 0.75 lb a.i./A, 1 application

Short grass 180 205 11 7 52.3 17 2 11 9 27.5

Tall grass 82.5 9 4 53. 6 2 4 78. 7 54. 4 12.6- Page 31 of 87

-

Food Type Dietary

- Based

EEC (mg/kg

diet) Dose

- Based EEC (mg/kg

- body weight)

Mammals and

Birds Birds Mammals

All Size s

Classes Small (20 g) Medium (100 g) Large

(1000 g) Small

(15 g) Medium

(35 g) Large

(1000 g )

B roadleaf plants/small insects 101 115 65. 8 29.4 96.5 66.7 15. 5

Fruits/pods/(seeds, dietary only) 11. 3 12.8 7.31 3.27 10.7 7.41 1.72

Arthropods 70.5 80. 3 45. 8 20.5 67.2 46.4 10 .8

Seeds (granivore) N/A 2.85 1.62 0.73 2.38 1.65 0.38

Max Label Rate for Whe at, Barley, and Grapes : 0.5 lb a.i./A, 1 application

Short grass 120 13 7 77.9 34. 9 114 7 9.1 18.3

Tall grass 55 62.6 35.7 16 52.4 36.2 8.40

Broadleaf plants/small insects 67.5 76. 9 43.8 19.6 64. 4 44.5 10.3

Fruits/pods/(seeds, dietary only) 7.5 8.54 4.87 2.18 7.15 4.94 1.15

Arthropods 47 53.5 30.5 13.7 44.8 31 7.18

Seeds (granivore) N/A 1.90 1.08 0.48 1.59 1.10 0.25

Max Label Rate for Ornamentals : 2.8 lb s a.i./A, 1 application

Short grass 672 765 436 195 6 41 44 3 1 03

Tall grass 308 35 1 200 89. 6 29 4 20 3 4 7.1

Broadleaf plants/small insects 378 43 1 24 6 1 10 360 249 5 7.8

Fruits/pods/(seeds, dietary only) 42 47.8 27. 3 12.2 40 27. 7 6.42

Arthropods 263 300 17 1 76.5 25 1 1 73 40.2

Seeds (granivore) N/A 10.6 6.06 2.71 8.90 6.15 1.43

Max Label Rate for Turf : 4 lb s a.i./A, 5 application s , 14

- day interval

Short grass 2973 338 7 1931 86 5 283 5 1959 454

Tall grass 136 3 1552 885 396 1299 898 208

Broadleaf plants/small insects 167 3 190 5 1086 486 159 5 1102 25 6

Fruits/pods/(seeds, dietary only) 18 6 21 2 121 54 177 122 28. 4

Arthropods 116 5 132 6 756 33 9 1110 767 17 8

Seeds (granivore) N/A 47.0 26.8 12.0 39. 4 27.2 6.31

Max Label Rate for Pumpkin (Hybrid seed production in IL only) : 0.25 lb a.i./A, 6 application s, 7

- day interval

Short grass 261.75 298.11 169.99 76.11 24 9.56 172.48 39.99

Tall grass 119.97 136.63 77.91 34.88 114.38 79.05 18.33

Broadleaf plants/small insects 147.23 167.69 95.62 42.81 140.38 97.02 22.49

Fruits/pods/(seeds, dietary only) 16.36 18.63 10.62 4.76 15.60 10.78 2.50

Arthropods 102.52 116.76 66. 58 29.81 97.74 67.55 15.66- Page 32 of 87

-

Food Type Dietary

- Based

EEC (mg/kg

diet) Dose

- Based EEC (mg/kg

- body weight)

Mammals and

Birds Birds Mammals

All Size s

Classes Small (20 g) Medium (100 g) Large

(1000 g) Small

(15 g) Medium

(35 g) Large

(1000 g )

Seeds (granivore) N/A 4.14 2.36 1.06 3.47 2.40 0.56

Max Label Rate for Cucumber, Pumpkins, and S quash (Hybrid seed production in CA only): 0.25 lb a.i./A, 6 application s, 3

- day interval

Short grass 311.91 355.23 202.57 90.69 2 97.38 205.53 47.65

Tall grass 142.96 162.82 92.84 41.57 136.30 94.20 21.84

Broadleaf plants/small insects 175.45 199.82 113.95 51.01 167.28 115.61 26.80

Fruits/pods/(seeds, dietary only) 19.49 22.20 12.66 5.67 18.59 12.85 2.98

Arthropods 122.16 139.13 79.34 35.52 116.47 80.50 18.66

Seeds (granivore) N/A 4.93 2.81 1.26 4.13 2.85 0.66

### 33 3.2.3.4. Exposure to Honey bee s

Potential risk to bees is assessed in this document according to the tiering process described in

the Guidance for Assessing Pesticid e Risks to Bees (USEPA et al., 2014)

. As part of the Tier I

risk assessment, screening

- l evel exposures are estimated in pollen and nectar using generic

residue data generated from other chemicals as well as other plant parts as described Table 8 4

. For dietary exposures resulting from foliar applicati ons, it is assumed that pesticide re sidues on

tall grass (from the K enaga nomogram of T

- REX) are a suitable surrogate for residues in pollen

and nectar of flowers that are directly sprayed during application. For contact exposure,

exposure estimates are b ased on the work of Koch and Weisser 4 

### (Koch and Weißer, 1997)

. For

soil applications, pesticide concentrations in pollen and nectar are assumed to be consistent with

chemical concentrations in the xylem of barley (calculated using the Briggs’ model). For seed

treatments, pesticide concentrations in pollen and nectar are based on concentrations in leaves

and stems of treated plants (based on the European and Mediterranean Plant Protection

Organization (EPPO) default value discussed in the White Paper), assumed to be 1 milligram per

kilogram (mg/kg) or 1 part per million (ppm). More details on these methods are available in the

in the T

- REX User’s Guide 5



### .

The Tier I method is intended to generate “reasonabl y conservative” estimates of pesticide

exposure to honey bee s which are then refined using available empirical residue data from a

variety of crops ; however, these data are not available for ethephon . The Tier I exposure method

is intended to account for t he major routes of pesticide exposure that are relevant to bees ( i.e

., through diet and contact). Exposure routes for bees differ based on application type. Under the

approach used in this assessment, bees foraging in a field treated with a pesticide thr ough foliar

spray could potentially be exposed to the pesticide through direct spray, i.e. , contact, as well

through consuming ethephon residues in pollen and nectar. Table 8 4 summarizes exposure

estimates for hone y bees for the Tier I assessment.

Table 8 4 . Screening

- level EECs for honey bee s based on foliar applications

.

Use Exposure

Route Exposure Estimate Calculation 1 Life

stage EEC

(μg

a

. i

. /bee/day)

Max Label Rate for Turf: 4 lbs

a.i. /A , 5 application s , 14

- day

interval Contact APP*(2.7 μ g a

. i

. /bee) Adults 10.8

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 128

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 55

Max Label Rate for

Ornamentals: 2.8 lbs a.i./A, 1

application Contact APP*( 2.7 μ g a.i. /bee) Adults 7.56

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 89.9

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 38.2

Max Label Rate for Cotton,

Tobacco, Apples, Berries, and

Pineapple: 2 lbs a.i./A, 1

application Contact APP*(2.7 μ g a.i./ bee) Adults 5.4

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 64.2

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 27.3

Max Label Rate for Tomatoes

(including tomatoes for Contact APP*(2.7 a.i./bee) Adults 4.4

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 52.4

4 Koch, H. and P. Weißer. 1997. Exposure of honey bees during pesticide application under field conditions.

Apidologie

, 28 : 439

- 44 7.

5 http://www.epa.gov/oppefed1/models/terrestrial/trex/t_rex_user_guide.htm

### 34

processing): 1.63 lbs a.i./A, 1

application Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 22.2

Max Label Rate Used on

Tomatoes

- Fresh Market (CA

only) and Walnuts: 1.25 lbs

a.i./A, 1 application Contact APP*(2.7 a.i./bee) Adults 3.4

Diet APP* (110 μ g a.i /g)*(0.292 g/day) Adults 40.2

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 17.1

Max Label Rate for Peppers,

Cherries, and Sugarcane: 1 lb

a.i./A, 1 application Contact APP*(2.7 a.i./bee) Adults 2.7

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Ad ults 32.1

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 13.6

Max Label Rate for

Cantaloupes (TX only): 0.75

lb a.i./A, 1 application Contact APP*(2.7 a.i./bee) Adults 2.03

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 24.1

Diet APP*(110 μ g a.i /g)*(0 .124 g/day) Brood 10.2

Max Label Rate for Wheat,

Barley, and Grapes: 0.5 lb

a.i./A, 1 application Contact APP*(2.7 a.i./bee) Adults 1.35

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 16.1

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 6.82

Max Label Ra te for Pumpkin

(Hybrid seed production in IL

only): 0.25 lb a.i./A, 6

applications, 7

- day interval Contact APP*(2.7 a.i./bee) Adults 0.68

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 8.03

Diet APP*(110 μ g a.i /g)*(0.124 g/day) Brood 3.41

Max Label Ra te for

Cucumber, Pumpkins, and

Squash (Hybrid seed

production in CA only): 0.25

lb a.i./A, 6 applications, 3

- day

interval Contact APP*(2.7 a.i./bee) Adults 0.68

Diet APP*(110 μ g a.i /g)*(0.292 g/day) Adults 8.03

Diet APP*(110 μ g a.i /g)*(0.124 g/day) B rood 3.41

APP = application rate in lbs ai/A

*The label maximum single application rate was modeled

1 Based on food consumption rates for larvae (0.124 g/day) and adult (0.292 g/day) worker bees and concentration in

pollen and nectar.



### 3. 2

. 3.2. Runoff and Spray Drift to Terrestrial and Semi

- Aquatic Plants

TERRPLANT (Version 1.2.2) 6 

### is used to calculate EECs for non

- target plants that inhabit dry

and semi

- aquatic areas. In this assessment, exposure to non

- target plants is calculated based on

the potent ial runoff and spray drift of foliar applications of ethephon and potential runoff after

soil and seed treatment applications ( Table 9 5 ). TERRPLANT does not account for particulate

drift.

Table 9 5 . EECs for Non

- target Terrestrial and Semi

- aquatic P lants for E thephon (based on

TERRPLANT)

.

Uses App

Technique Single Max.

App. Rate

(lbs a

. i

. /A) EECs (lbs a

. i

. /A)

Semi

- Aquatic

Areas (Total) Dry Areas

(Total)

Max Label Rate for Turf: 4 lbs a. i./A * Foliar 4 2.0 4 0.24

Max Label Rate for Ornamentals Foliar 2.8 1.43 0.17

Max Label Rate for Cotton, Tobacco,

Apples, Berries, and Pineapple Foliar 2 .0 1.1 0.2

6 http://www.epa.gov/oppefed1/models/terrestrial/

### 35

Max Label Rate for Tomatoes (including

tomatoes for processing) Foliar 1.63 0.90 0.16

Max Label Rate Used on Tomatoes

- Fresh

Market (CA only) and Walnuts Foliar 1.25 0.70 0.13

Max Label Rate for Peppers, Cherries, and

Sugarcane Foliar 1.0 0.55 0.1

Max Label Rate for Cantaloupes (TX only ) Foliar 0.75 0.41 0.08

Max Label Rate for Wheat, Barle y, and

Grapes Foliar 0.5 0.28 0.05

Max Label Rate for Pumpkin (Hybrid seed

production in IL only) and Cucumber,

Pumpkins, and Squash (Hybrid seed

production in CA only) * Foliar

0.25 0.13 0.02

App = Application

* A single application was modeled, consisten t with the model input parameter guidance



### The spray drift model AgDrift version 2.1.1 is also used to provide bounds defining the spatial

extent of risk concern resulting from off

- field drift at currently registered ethephon application

rates.

3.3

. E cological Effects Characterization

The ecological effects characterization for ethephon is based up on registrant

- submitted toxicity

data for the technical grade active ingredient ( TGAI ) and for formulations

. The ecotoxicity data

for ethephon and its ass ociated products have been reviewed previously in multiple ecological

risk assessments (USEPA, 2013 ) (USEPA, 2006 ) and in a Preliminary Problem Formulation for

Registration Review (USEPA, 2010 , DP Barcode 371952 )

. These data are summarized briefly in

Sections 3.3.1 and 3.3. 2. Various studies with terrestrial and aquatic plants, birds, and aquatic

animals exposed to TGAI ethephon have been received since the Problem Formulation was

issued in 2010 ; the results of these studies are described briefly in this section

.

The res ults of a 2015 review of the Ecological Incident Information System (EIIS) are described

in Section 3.3.3 (USEPA, 2012a)

. In addition, the ECOTOX open literature report prepared in

2009 was reviewed in 2010 for the ethephon Problem Formulation. Data were further examined

if e ndpoints were more sensitive (lower) than endpoints available from submitted studies or were

available for amphibians, freshwater molluscs, or reptiles (USEPA, 2011) . Data meeting the

OPP’s stand ard for inclusion in risk assessment

( http://www.epa.gov/pesticides/science/literature

- studies.html ) were available in ECOTOX that

showed greater sensitivity than results from su bmitted studies for aquatic nonvascular plants (Ma

et al, 2004, ECOTOX Number E095681) . An ECOTOX refresh report was not availab le for

ethephon at the time of the writing of this preliminary risk assessment

. The endpoints from the

ECOTOX

- ca talogued open literature studies are provided in Appendix F , for reference.

### 36

3.3.1. Aquatic Toxicit y Assessment

A summary of the most sensitive toxicity endpoints for aquatic organisms is shown in Table

10 6 . These endpoints will be used to calculate risk quotients.

The available data indicate that ethephon TGA I is slightly toxic to freshwater fish and freshwater

and estuarine/marine invertebrates on an acute exposure basis. No chronic estuarine/marine fish

studies are available. Effects on fry hatching success were observed in the available chronic

freshwater fish study at 86 m g a.i./L

. A dult length was significantly reduced at 38 mg a.i./L in

the available chronic daphnid study

. Effects on survival were observed in the v a scular aquatic

plant duckweed ( Lemna gibba ; EC 50 

### = 2.49 mg a.i./L, EC 05 

### = 0.017 m g a.i./L) and inhibited

growth was observed when nonvascular freshwater green alga ( Chlorella pyrenoidosa ; EC 50 

### =

23.5 mg a.i./L , NOAEC= 2 mg a.i./L ) was exposed to ethephon at 5 m g a.i./L.

Table 10 6 . Summary of Most Sensitive Toxicity Dat a for Aquatic Organisms Exposed to

Ethephon (TGAI).

Common Name

(Species) Study Type

and

( Duration of

Exposure) Test

Substance

(% a.i.) Endpoint

(Effect Observed

at Endpoint) Toxicity Value

(95% CI)

m g a.i./L

(Acute Toxicity

Category) MRID

Study

Classifica tion 1

Freshwater Fish (Surrogate for Aquatic

- phase A mphibians )

Fathead m innow

( Pimephales promelas ) Static

( 96

- hour ) TGAI

( Not

specified ) LC 50

(Survival) 88 (73.2

- 106)

(slightly toxic) 00027496

Supplemental

Fathead m innow

( Pimephales promelas ) Flow

- thro ugh

(3 4

- day) TGAI

(71.4%) NOAEC /LOAEC

(survival at hatch) 43 / 86 48202004

Acceptable

Estuarine/Marine Fish

Sheepshead m innow

( Cyprinodon

variegatus ) Acute TGAI

( 73.8%) LC 50

(Survival) >102

(Practically

nontoxic) 49040501

Acceptable

Sheepshead m innow

( Cy prinodon

variegatus ) Chronic

-- NOAEC >50 2 ACR

Freshwater Aquatic Invertebrates

Water flea

(Daphnia magna) Static

(48

- hour) TGAI

(88.3%) EC 50

(Immobility) 31.7

(slightly toxic) 00054013

Supplemental

Water flea

(Daphnia magna) Flow

- through

(21

- days) TG AI

( 71 .2%) NOAEC /LOAEC

( length ) 17/38 42294501

Acceptable

Estuarine/marine Aquatic Invertebrates

Eastern oyster

( Crassostrea virginica ) Flow

- through

(96

- hour) TGAI

( 72.2 %) Growth

( reduced shell

deposition ) 60 (25

- 93)

( slightly toxic ) 41296202

Acceptabl e

G rass shrimp

( Palaemonetes spp. ) Chronic

-- NOAEC >198 3 ACR

Aquatic Plants

Duckweed

( Lemna gibba ) Static Renewal

14

- day TGAI

( 71.9 %) EC 50

( Survival ) 2.5 ( Slope: 0.65;

CI: 1.34

- 9.48 ) 41509001

Acceptable EC 05 0.017

### 37

Common Name

(Species) Study Type

and

( Duration of

Exposure) Test

Substance

(% a.i.) Endpoint

(Effect Observed

at Endpoint) Toxicity Value

(95% CI)

m g a.i./L

(Acute Toxicity

Category) MRID

Study

Classifica tion 1

Freshwater green alga

( Chlorella pyrenoidosa ) 96

- hr TGAI

( 85 %) EC 50

( growth inhibition) 23.5 Acceptable

E095681

NOAEC/LOAEC 2/5 Acceptable

E095681

TGAI=technical grade active ingredient:

1 Supplemental studies may or may not be suitable to calculate RQs. Quantitative values are s uitable for calculation

of RQ. Qualitative values are not considered suitable for calculation of RQs but may be useful in understanding the

weight of evidence for evaluating the likelihood of risk.

2 This NOAEC is based on the acute

- to

- chronic ratio using fathead minnow endpoints [ 88/43

= 2.1 (ACR)] and the

96

- hour LC 50 of the sheepshead minnow

.

3 This NOAEC is based on the acute

- to

- chronic ratio using water flea endpoints [31.7/17=1.9 (ACR)] and the grass

shrimp 96

- hour LC 50 (>370 mg a.i./L).



### 3.3.1.1. Tox icity to Aquatic Vertebrates

On an acute exposure basis, ethephon TGAI is slightly toxic to practically nontoxic to freshwater

fish , with 96

- hour LC 50 

### values ranging from 88 mg a.i./L for the f athead minnow ( Pimephales

promelas ; MRID 27496 ) to 357 m g a.i. /L for the rainbow trout ( Oncorhynchus mykiss ; MRID

252943 )

. On an acute exposure basis, ethephon TGAI is practically nontoxic to estuarine/marine

fish, with a 96

- hour nondefinitive LC 50 

### value of >102 mg a.i./L for s heepshead minnow

( Cyprinodon variegatus ; MRID 49040501)

.

One freshwater fish early

- life stage study was submitted ( Pimephales promelas ; MRID

48202004) where survival of organisms at hatch averaged 73% for the control level, compared to

72, 71, 66, 72, and 0% for the mean

- measured 5.0, 10, 21 , 43, and 86 mg a

. i

. /L levels,

respectively. The survival at the 86 mg ai/L level was statistically significant compared to the

control . The study NOAEC and LOAEC were 43 mg a

. i

. /L and 86 mg a

. i

. /L

, respectively, based

on survival at hatch

. No chronic es tuarine/marine fish studies are available ; however, an acute

to

- chronic ratio (ACR) was determined from fathead minnow endpoints [88/43=2.1] and applied

to the 96

- hour LC 50 

### of the sheepshead minnow to estimate the chronic toxicity of ethephon to

estuarine/ marine fish. Since the acute sheepshead minnow endpoint is non definitive (>102 mg

a.i./L ), the estimated chronic sheepshead minnow endpoint is also non definitive (>50 mg a.i./L ).

3.3.1.2. Toxicity to Aquatic Invertebrates

On an acute exposure basis, ethephon is slightly toxic to practically nontoxic to freshwater

invertebrates, with water

- column 48

- hour E C 50 

### values ranging from 31.7 m g a.i./L for the water

flea ( Daphnia magna ; MRID 000 54013) to 165 m g a.i./L for the midge ( Chironomus te n tans ;

MRID 000 54013)

. E thephon is also slightly toxic to practically nontoxic to e stuarine/marine

invertebrate s

, with 96

- hour I C 50 

### values ranging from 60 m g a.i./L for the e astern oyster

( Crassostrea virginica ; MRID 41296202 ) based on inhibition of shell growth to a 96

- hour L C 50

### 38

of >370 mg a.i./L for the grass shrimp ( Palaemonetes spp. ; MRID 000 54013 )

.

Chronic toxicity data are available for freshwater but not estuarine / marine invertebrates. For the

water flea ( Daphnia magna ) , the 21

- day NOAEC/ LOAEC was 17 / 38 m g a.i. /L (MRID

42294501 ) based on a statistically significant (p<0.05) 3.5% reduction of adult body lengt h in

the 38 mg a.i./L treatment compared to the control

. The estuarine / marine invertebrate NOAEC

is based on the ACR derived from water flea endpoints [31.7 /17=1.9] which was subsequently

applied to the 96

- hour LC 50 

### of the grass shrimp ( >370 mg a.i./L ), resulting in an estimate d

chronic toxicity of >198 mg a.i./L for grass shrimp

. The ACR was not applied to the most

sensitive acute toxicity value ( i.e. , the endpoint used for RQ determination) because it is of

questionable validity to compare the mollusc shell growth inhibition test sublethal effects

endpoint to the lethality endpoint from a test with non

- molluscs.

3.3.1.3. Toxicity to Aquatic Plants

Tier I toxicity testing with duckweed ( Lemna gibba ) exposed to 1.5 mg a.i./L ethephon TGAI

resulted in a 56.1% decrease in frond production co mpared to controls. In a Tier II test, exposure

to the highest test concentration (1.6 mg a.i./L) resulted in growth in hibition of 46.1%, compared

to controls. The estimated EC 50 

### for the Tier II test was 2.5 mg a.i./L. Statistically significant

effects were observed at all test concentrations ( 19, 23, 27, 39, and 46% growth reductions were

recorded in the 0.10 , 0.17, 0. 44, 0.81, and 1.6 mg a.i./L treatment compared to the control );

therefore, the NOAEC was not established. The EC 05 

### was estimated as 0.017 mg a.i./L (MRID

41509001).

Data from T ier 1 studies are available for 4 species of non

- vascular plants ( Skeletonem a

cosatum, Navicula pelliculosa, Anabaena flos

- aquae and Pseudokirchneriella subcapitata

formerly Selenastrum capricornutum ) exposed to ≥1.4 mg a.i./L ethephon for 120 hours. In

these studies, cell densities of treatment groups were not significantly diff erent when compared

to controls ( MRIDs 41403301,

- 02,

- 03 and

- 04).

In a study located in the scientific literature (Ma et al. , 2004; ECOTOX # 0 95681), 4 species of

non

- vascular aquatic plants were exposed to 85% ethephon. The study authors reported EC 50 

### values (based on growth inhibition) ranging 23.5

- 174 mg/L, with NOECs ranging from 2

- 50

mg/L

.

3.3.2. Terrestrial Effects Characterization

A summary of the most sensitive terrestrial animal toxicity data for ethephon , based on a current

EPA review of all submitted data, is provided in Table 11 7 and is discussed further in Sections

3.3.2.1 to 3.3.2.3. The available data indicate that ethephon TGAI ranges from practically non

toxic to slightly toxic to birds, includ ing passerines

, and is slightly toxic to mammals on an acute

oral exposure basis and highly toxic to mammals on an sub acute

- dietary exposure basis

. Ethephon is practically non

- toxic to young adult honey bees on an acute oral and contact

exposure basis

.

### 39

M allard duck (

Anas platyrhynchos ) fed diets containing ethephon for 20

- weeks were found to

have significantly fewer hatchlings per eggs set and surviving hatchlings per eggs set relative to

controls at 300 mg a.i./kg

- diet ; however, there were no effects to any parameter evaluated at the

955 mg a.i./kg diet treatment compared to the control

. Laboratory rats fed diets containing

ethephon (3000 mg a.i./kg

- diet) had significant bodyweight and food consumption reductions

relative to controls.

The available data for terrestrial plants exposed to technical e thephon for formulation into end

use products (71.9

- 73.8% a.i. ) described in Section 3.3.2.4, indicate that ethephon exposure to

seeds and/or emerging plants ( i.e. , seedling emergence) resulted in significantly reduced plant

height at application rates equivalent to 0. 22 lb a.i./A compared to the control (significant effects

to emergence and survival were recorded for a dicot species tested at 0.32 lb a.i./A ) . Ethephon

exposure to foliage ( i.e. , vegetative vigo r) resulted in significantly reduced plant height at

application rates equivalent to 0.00 8 lb a.i./A compared to the control

.

Table 11 7 . Summary of the Most Sensitive Toxicity Data for Terrestrial Animals Exposed

to Ethephon

.

Com mon Name

(Species) Study Type

(Duration of

Exposure) Test

Substance

(% a.i.) Endpoint

(Effect at

endpoint) Toxicity Value

(95% CI)

(Acute Toxicity

Category) MRID

Study

Classification

Birds

Canary

( Serinus canaria) Acute Oral

( capsule with 14

- day observa tion) TGAI

( 73.8 %) L D 50

(Mortality) 1640 mg a

. i

. /kg

- bw

( 1230

- 2480 )

Slope

= 6.1 (1.9

- 10.3)

( slightly toxic) 49160601

Acceptable

Bobwhite quail

( Colinus

virginianus) Acute Oral (Oral

gavage with 14

- day observation) TGAI

(75 %) LD 50

(Mortality) 596 mg a.i./k g

- bw

( 521

- 681 )*

( slightly toxic) 00027493

Acceptable

Bobwhite quail

( Colinus

virginianus) Subacute Dietary

(8

- day) TGAI

( 71.3 %) L C 50

(Mortality) >5000 mg a.i./kg

- diet

( practically non toxic) 41080201

Acceptable

Mallard duck

( Anas

platyrhynchos ) Reproduct ion

(20 week) TGAI

( 73.8 %) NOAEC/

LOAEC

( hatchlings per

eggs set ) 10 6 / 300 mg a.i./kg

- diet* 49305605

Supplemental

Quantitative

Mammals 1

Laboratory rat

(Rattus

norvegicus) Acute Oral TGAI

(75%) LD 50

(Mortality) 1205 mg a.i. /kg

- bw

( slightly toxic ) 00029 509

Laboratory rat

(Rattus

norvegicus) Two

- generation

Reproduction TGAI NOAEL/

LOAEL

( bodyweight

and food

consumption

reductions ) NOAEL: 300 mg a.i. /kg

diet* or

24 mg a.i. /kg/day/

LOAEL: 3000 mg a.i. /kg

diet or

245 mg a.i. /kg/day 41508701

Honey bee s

### 40

Com mon Name

(Species) Study Type

(Duration of

Exposure) Test

Substance

(% a.i.) Endpoint

(Effect at

endpoint) Toxicity Value

(95% CI)

(Acute Toxicity

Category) MRID

Study

Classification

Ho ney Bee

(Apis mellifera) Acute c ontact

( 48

- hour) 71.6% L C 50 (Mortality) > 0. 100 m g a.i./bee

( practically non toxic) 48202006

Acceptable

Acute oral

( 48

- hour) 71.6% LD 50 (Mortality) > 0. 1 17 m g a.i./bee

( practically non toxic) 48202006

Acceptable

* Most sensit ive endpoint; will be used in RQ calculations.

1 M ammalian toxicity endpoints were provided and reviewed by EPA/OCSPP/OPP Health Effects Division



### 3.3.2.1. Toxicity to Animals

Etheph on is classified slightly toxic to birds on an acute oral exposure basis

. Two acute oral

toxicity s tudies have been submitted for n orthern bobwhite quail ( Colinus virginianus ) exposed

to technical ethephon. In these studies, LD 50 

### values were 596 (521

- 681) mg/kg (MIRD

00027493) and 1072 (907

- 1267) mg/kg (MRID 00026041). In a n acute oral study with the

mallard duck (

Anas platyrhyncos ) exposed to technical ethephon, the LD 50 

### was 1998 (1748

- 2283) mg/kg (MRID 00026040).

On a subacute dietary basis, ethephon is classified practically non

- toxic. Data are available from

two regis trant submitted studies where 8

- d LC 50 

### values were >5000 mg/kg

- diet for bobwhite

quail (MRID 41080201) and mallard duck (MRID 00056480).

Since the time of the Problem Formulation, three avian reproduction studies (MRIDs 48202005,

49305605, and 49325701) a nd one passerine acute oral toxicity study (MRID 49160601) have

been submitted and reviewed. MRID 48202005 is a Japanese quail ( Couturnix japonica ) avian

reproduction test that was classified as supplemental because NOAECs could not be established

for the most sensitive endpoints (number of hatchlings and hatchling survival) and because of

test species selection (the Japanese quail is not a preferred test species). Studies with mallard

and bobwhite quail were conducted and submitted between 2012 and 2014 (MRIDs 49305605

and 49325701). Both mallard and bobwhite avian reproduction studies included dietary

exposure concentrations greater than environmental exposures estimated to result from the

highest registered single application rate of ethephon; however, environmental exposures

estimated to result from multiple applications of ethephon to turf exceed the highest dietary

exposure concentration of these studies. Since t he avian reproduction NOAEC has been

established below the highest concentration tested, this uncertainty d oes not affect chronic avian

risk estimation.

The mallard avian reproduction study (MRID 49305605) is the source of the lowest avian

chronic endpoint which is used to calculate RQs. 15 pairs per level of 20

- week old mallard duck

( Anas platyrhynchos ) were exposed to technical ethephon at m ean

- measured concentrations of

<20 (<LOQ, negative control), 106, 300 and 955 mg ai/kg diet, over ca. 20 we eks. T he number

of hatchlings per eggs set and hatchling survival per eggs set were significantly reduced in the

300 mg a.i./kg diet treatment compared to the control ; however, there were no significant effects

to these parameters at the highest test conc entration (955 mg a.i./kg diet). S ince more than a

quarter of the pens at the 300 mg a.i./kg diet treatment had a strikingly low number of viable

### 41

embryos it is uncertain whether the effects on the number of hatchlings per eggs set and the

number of hatchl ings surviving at 14 days post hatch per eggs set were toxicant mediated, the

result of a greater proportion of sensitive birds in the 300 mg ai/kg diet treatment, or related to

husbandry; however, the effects at the 300 mg ai/kg diet treatment are conserv atively considered

to be a direct result of ethephon exposure. Therefore, the mallard avian reproduction NOAEC

and LOAEC are conservatively established at 106 and 300 mg ai/kg diet

, respectively.

I n acute oral toxicity testing with the passerine canary ( Serinus canaria ; MRID 49160601 ) , no

regurgitation was observed following dosing with two gelatin capsules per bird

. Observations

continued for 14

- days during which 70% mortality was recorded at the highest treatment and the

LD 50 

### was 1640 mg ai/kg bw

.

E thephon is slightly toxic to mammals on an acute oral exposure basis. The acute oral LD 50 

### was

1205 mg a.i./kg

- bw (corrected for 75% a.i.; MRID 00029509). Additional data were available to

describe the acute oral toxicity of ethephon to rats. The LD 50 

### va lues for males, females and

combined sexes, when corrected for percent a.i., were 2641, 1565, and 2145 mg a.i./kg

- bw

, respectively (MRID 41154501).

In a 2

- generation reproduction study, the LOAEL for ethephon parental toxicity was 3,000 ppm

(245 mg a.i./k g/day) based on decrements in adult female pre

- mating body weight, reduced food

consumption and relative food utilization. The LOAEL for offspring toxicity was 3000 ppm

(245 mg a.i./kg/day) based on body weight decrease (4.5% relative to controls) . The r esulting

NOAEL for the study was 300 ppm (24 mg a.i. mg/kg/day) (MRID 41508701).

As of September 15, 2009, no additional acute or chronic toxicity data for animals exposed to

ethephon were identified in the scientific literature (based on a search of EC OTOX).

Additional honey bee toxicity data have also been received since the time of the Problem

Formulation. The honey bee, Apis mellifera L., was exposed to ethephon (71.4% a.i.) for 48

hours in oral and contact toxicity tests (MRID 48202006). The oral and contact nominal

concentrations were 0 (solvent control), 6.3, 12.5, 25, 50, and 100 μg ai/bee. The measured

concentrations of e thephon i n the oral toxicity test were 7.3, 14.2, 28.5, 58.5, and 116.5 μg

ai/bee

. By 48 hours in the oral test, mortality was 0, 3, 0, 7, and 0%. One bee in the 58.5 μg

ai/bee test level had coordination problems at 4 hours, which did not persist. By 48 hours in the

contact test, there was no mortality in the controls or treatment groups

. T here were no sub

- lethal

effects. The LC 50 

### value for the oral test was >116.5 μg ai/bee . The LD 50 

### value for the contact

test was >100 μg ai/bee

. As a result, e thephon is categorized as practically nontoxic to honey

bees on an acute oral and contact basis. The NOAELs for the oral and c ontact tests were 116.5

and 100 μg ai/bee, respectively.

3.3.2.4. Toxicity to Terrestrial Plants

Terrestrial plant toxicity studies are required for pesticides that have terrestrial use patterns or

may move off of the application site

. The NOAEL and IC 25 

### (concentration that causes an

### 42

inhibitory effect in 25% of the population for the monitored endpoint) values are established for

markers of seedling emergence and vegetative vigor.

Seedling emergence and vegetative vigor data are available for 6 speci es of dicots and 4 species

of monocots (MRIDs 41403305, 41659401 , 49037901, 49037902 ) ( Table 1 8 )

. These studies

were conducted with 71.3

- 73.8% active ingredient ethephon formulations . While the tested

formulations were not typical end use products (TEPs) as required by 40 CFR §158.660, the

tested products are understood to approximate ethephon TEPs compositionally ( i.e. , the ethephon

TEPs do not contain additional surfactants, wetting agents, or other inert ingredients compared to

the tested formulations of higher active ingredient percentage) when diluted with water.

The lowest available IC 25 

### values for mon ocots are 0.24 lb a.i./A for seedling emergence of

ryegrass and 2.1 lbs a.i./A for vegetative vigor of corn (MRIDs 41659401 and 49037902,

respectively ) . The corresponding NOAEC value for seedling emergence of ryegrass is 0.11 lbs

a.i./A. The corresponding NOAEC value for vegetative vigor of corn is 0.127 lb a.i./A.

The lowest available I C 25 

### values for dicots are 0.318 lb a.i./A for seedling emergen ce of cabbage

and 0. 0106 lb a.i./A for vegetative vigor of cucumber

. The corresponding NOAEC value for

seedling emergence of cabbage is 0.127 lb a.i./A. Because there were significant effects at all

treatment concentrations for cucumber shoot length, a N OAEC could not be established

. According to EFED policy, in the ab sence of a suitable NOAEC, the I C 05 

### is used as a surrogate.

The corresponding I C 05 

### value for vegetative vigor of cucumber is 0.000418 lb a.i./A.

Table 12 8

. Summary of Terrestrial Plants Toxicity Data for Ethephon Formulations.

Crop Formulation

(% a.i.) Species I C 25

(lbs a.i./A) NOAEC

or IC 05 /

LOAEC

(lbs a.i./A) Most Sensitive

Endpoint

Affected MRID

Study Classification

Seedling Emergence

Monocots Ethephon

[for

for mulation

into end

- use

products]

(73.8%) Ryegrass

( Lolium

perenne ) 0.24* 0.11*/

0.22 Shoot length

49037901

Supplemental

quantitative Dicots Cabbage

( Brassica

oleracea ) 0.318* 0.127*/

0.318 Emergence,

survival

Vegetative Vigor

Monocots Ethephon

[for

f ormulation

into end

- use

products]

(73.8%) Corn ( Zea

mays ) 2.1 * 0.127 * /

0.318 Shoot length

49037902

Supplemental

quantitative Dicots Cucumber

( Cucumis

sativus ) 0.0106 * 0.000418 *† /

0.00799 Shoot length

* Most sensitive endpoint used for risk estimation ( i.e. , RQ calculations) or risk description (for non

- definitive

endpoints).

†The IC 05 is reported because there were significant effects at all treatment concentrations

### 43

4. Risk Characterization

4.1. Risk Estimation

This assessment of the labeled uses of ethephon relies on the deterministic RQ method to provide

a metric of potential risks. The RQ provides a comparison of exposure estimates to toxicity

endpoints ( i.e. , estimated exposures divided by acute and/or chronic toxicity endpoints expressed

in the same units as exposures, respectively). The resulting unitless RQ values , calculated in the

Risk Estimation Section) are compared to the Agency’s LOCs (see Table 4 ) . The LOCs are

used by the Agency to indicate wh en the use of a pesticide, as directed by the label, has the

potential to result in exposure levels sufficient to cause adverse effects to non

- target organisms.

For endangered species, LOC exceedances require an additional in

- depth listed species

evaluati on to characterize risks for the potential co

- occurrence of listed species and areas in

which crops are grown. In this approach, RQs that exceed non

- listed species LOCs necessarily

also exceed the corresponding listed species LOCs. Acute risk LOCs are di fferent for listed and

non

- listed taxa; however, the chronic LOC is 1.0 across all animals

. For plants, unlike for

animals, RQ values are not presented for acute versus chronic risk; instead, RQ values are

presented for listed and non

- listed species based on a comparison of a given EEC to NOAEL and

EC 25 

### values (for terrestrial plants) and EC 50 

### values (for aquatic plants), respectively. The LOC

for all plants is 1.0. A discussion of the RQ values for ethephon and of other information that

provides context for the interpretation of potential risk to various taxa is presented in the Risk

Description in Section 4.2

. Risk quotients were estimated for maximum labeled rates.

4.1.1

. RQ Values for Aquatic Organisms

The SWCC was used to calculate water

- colu mn 1

- in

- 10

- year peak, 21

- day average, and 60

- day

average EECs for aquatic organism s . Toxicity endpoints used to calculate risk quotients are the

most sensitive acute and chronic endpoints for each tax on and are specified in the table showing

the RQ value.

Freshwater fish serve as surrogates for aquatic

- phase amphibians . RQ values based on both

maximum application rates for freshwater and estuarine/marine fish exposed to ethephon are l ess

than 0.01, below the LOC (0.05) for acute risk for listed species f or all registered uses ( Table 19 ).

Similarly, chronic RQ values for freshwater and estuarine/marine fish are less than the chronic

risk LOC (1.0) for maximum label rates for all uses.

Table 19 . RQs for Direct Ef fects to Fish from Ethephon Use

Model scenario App.

Rate

(lbs

a.i./A) Peak

EECs

(m g

a.i./L) 60

- day

average

EECs Risk Quotients

Freshwater Fish Estuarine/Marine Fish

Acute

LC 50 = 88 m g

a.i./L Chronic

NOAEC =

43 m g

a.i./L Acute

EC 50 =

>102 m g

a.i. /L Chronic

NOAEC = >50

m g a.i./L 1

Maximum Label Rates

– Runoff and Spray Drift Simulated

OR berries 2.0 0.014 0.0005 < 0.0 1 < 0.01 < 0.01 < 0.01

FL cucumber 0.25 0.00 4 0.0004 < 0.01 < 0.01 < 0.01 < 0.01

MS cotton 2.0 0.01 4 0.0009 < 0.01 < 0.01 < 0.01 < 0.01

FL sugarcane 1.0 0.004 0.0002 < 0.01 < 0.01 < 0.01 < 0.01

### 44

NC tobacco 2.0 0.00 7 0.0005 < 0.01 < 0.01 < 0.01 < 0.01

FL tomato 1.63 0.02 3 0.0010 < 0.01 < 0.01 < 0.01 < 0.01

PA tomato 1.63 0.013 0.0008 < 0.01 < 0.01 < 0.01 < 0.01

CA tomato 1.63 0.01 2 0.0006 < 0.01 < 0.01 < 0.01 < 0.01

FL turf 4 0.0 17 0.0030 < 0.01 < 0.01 < 0.01 < 0.01

ND wheat 0.5 0.003 0.0 002 < 0.01 < 0.01 < 0.01 < 0.01

NY grape 0.5 0.004 0.0003 < 0.01 < 0.01 < 0.01 < 0.01

OR filbert 1.25 0.009 0.0003 < 0.01 < 0.01 < 0.01 < 0.01

GA pecan 1.25 0.01 1 0.0006 < 0.01 < 0.01 < 0.01 < 0.01

CA almond 1.25 0.009 0.0003 < 0.01 < 0.01 < 0.01 < 0.01

FL nursery 2.8 0.0 16 0.0008 < 0.01 < 0.01 < 0.01 < 0.01

NJ nursery 2.8 0.01 4 0.0008 < 0.01 < 0.01 < 0.01 < 0.01

CA nursery 2.8 0.0 10 0.0003 < 0.01 < 0.01 < 0.01 < 0.01

NC apples 2.0 0.014 0.0008 < 0.01 < 0.01 < 0.01 < 0.01

MI cherries 1.0 0.004 0.000 3 < 0.01 < 0.01 < 0.01 < 0.01

Abbreviations: App.= Application

1 Estima ted using the estuarine/marine fish 96

- hr LC 50 of >102 m g a.i./L and a n ACR from freshwater fish



### RQ values based on maximum application rates for freshwater and estuarine/marine

invertebrates exposed to ethephon on an acute exposure basis are well below the LOCs for risk to

listed (LOC=0.05) and non

- listed (LOC=0.5) species ( Table 21 ). RQ values for freshwater and

estuarine/marine invertebrates

, based on chronic exposure to ethephon

, likewise do not exceed

LOCs for chron ic risk ( Table 2 0 )

.

Table 2 0 . RQs for Direct Effects to Aquatic Invertebrates from Ethephon Use

Model scenario App.

Rate

(lbs

a.i./A) Peak

EECs

(m g

a.i./L) 21

- day

average

EECs

(m g

a.i./L) Risk Quotients

Freshwater

Invertebrates E/M Invertebrates

Acute

EC 50 =

31 .7 m g

a.i./L Chronic

NOAEC =

17 m g

a.i./L Acute

EC 50 =

60 m g

a.i./L Chronic

NOAEC =

>198 m g

a.i./L 1

Maximum Label Rates

– Runoff and Spray Drift Simulated

OR berries 2.0 0.014 0.001 < 0.0 1 < 0.0 1 < 0.0 1 < 0.0 1

FL cucumber 0.25 0.00 4 0.001 < 0.01 < 0.01 < 0.01 < 0.01

MS cotton 2.0 0.01 4 0.002 < 0.01 < 0.01 < 0.01 < 0.01

FL sugarcane 1.0 0.004 0.0006 < 0.01 < 0.01 < 0.01 < 0.01

NC tobacco 2.0 0.00 7 0.001 < 0.01 < 0.01 < 0.01 < 0.01

FL tomato 1.63 0.02 3 0.003 < 0.01 < 0.01 < 0.01 < 0.01

PA tomato 1.63 0.013 0.002 < 0.01 < 0.01 < 0.01 < 0.01

CA tomato 1.63 0.012 0.002 < 0.01 < 0.01 < 0.01 < 0.01

FL turf 4 0.0 17 0.004 < 0.01 < 0.01 < 0.01 < 0.01

ND wheat 0.5 0.003 0.0006 < 0.01 < 0.01 < 0.01 < 0.01

NY grape 0.5 0.004 0.00 07 < 0.01 < 0.01 < 0.01 < 0.01

OR filbert 1.25 0.009 0.0009 < 0.01 < 0.01 < 0.01 < 0.01

GA pecan 1.25 0.01 1 0.002 < 0.01 < 0.01 < 0.01 < 0.01

CA almond 1.25 0.009 0.0009 < 0.01 < 0.01 < 0.01 < 0.01

FL nursery 2.8 0.0 16 0.002 < 0.01 < 0.01 < 0.01 < 0.01

NJ nursery 2.8 0.01 4 0.002 < 0.01 < 0.01 < 0.01 < 0.01

CA nursery 2.8 0.0 10 0.001 < 0.01 < 0.01 < 0.01 < 0.01

NC apples 2.0 0.014 0.002 < 0.01 < 0.01 < 0.01 < 0.01

### 45

MI cherries 1.0 0.004 0.0007 < 0.01 < 0.01 < 0.01 < 0.01

Abbreviations: App.= Application. ; E/M=estuarine/marine

1 Estimated using the estuarine/marine invertebrate (grass shrimp) 96

- hr LC 50 of >370 mg a.i./L and an ACR from

freshwater invertebrates.



### For aquatic vascular and non

- vascular plants exposed to ethephon, RQ values based on

maximum application rates equaled or exceeded the LOC (1.0) for risk to listed aquatic vascular

plant s associated with use on tomato and turf ; however RQs were considerably less than the

LOC for listed and non

- listed aquatic non

- vascular plants and non

- listed aquatic vascular plants

for t he same use patterns ( Table 2 1 ).

Table 2 1 . RQ Values for Direct Effects to Aquatic Vascular and Nonvascular Plants from

Ethephon Use

Model scenario App.

Rate

(lbs

a.i./A) Peak water

EEC

(m g a.i./L) Risk Quotients

Aquatic Vascular Plants Aquatic Non

- vascular Plants

Listed

EC 05 =

0.017 m g

a.i./L Non

- listed

EC 50 =

2.5 m g a.i./ L Listed

NOAEC =

2 m g a.i./L Non

- listed

EC 50 =

23.5 m g a.i./ L

Maximum Label Rates

– Runoff and Spray Drift Simulated

OR berries 2.0 0 .014 0.82 < 0.01 < 0.01 < 0.01

FL cucumber 0.25 0.00 4 0.24 < 0.01 < 0.01 < 0.01

MS cotton 2.0 0.01 4 0.82 < 0.01 < 0.01 < 0.01

FL sugarcane 1.0 0.004 0.24 < 0.01 < 0.01 < 0.01

NC tobacco 2.0 0.00 7 0.41 < 0.01 < 0.01 < 0.01

FL tomato 1.63 0.02 3 1.35 < 0 .01 0.01 < 0.01

PA tomato 1.63 0.013 0.76 < 0.01 < 0.01 < 0.01

CA tomato 1.63 0.012 0.71 < 0.01 < 0.01 < 0.01

FL turf 4 0.0 17 1.00 < 0.01 < 0.01 < 0.01

ND wheat 0.5 0.003 0.18 < 0.01 < 0.01 < 0.01

NY grape 0.5 0.004 0.24 < 0.01 < 0.01 < 0.01

OR filbe rt 1.25 0.009 0.53 < 0.01 < 0.01 < 0.01

GA pecan 1.25 0.01 1 0.65 < 0.01 < 0.01 < 0.01

CA almond 1.25 0.009 0.53 < 0.01 < 0.01 < 0.01

FL nursery 2.8 0.0 16 0.94 < 0.01 < 0.01 < 0.01

NJ nursery 2.8 0.01 4 0.82 < 0.01 < 0.01 < 0.01

CA nursery 2.8 0.0 10 0.5 9 < 0.01 < 0.01 < 0.01

NC apples 2.0 0.014 0.82 < 0.01 < 0.01 < 0.01

MI cherries 1.0 0.004 0.24 < 0.01 < 0.01 < 0.01

Abbreviations: App.= Application

RQs exceed ing the aquatic plant risk LOC of 1 .0 shown in bold font



### 4.1.2. RQ Values for Terrestrial Or ganisms

Exposure estimated for birds and mammals were calculated using upper

- bound K enaga values

calculated using T

- Rex version 1.5.2. As noted previously, b irds are the surrogate species for

reptiles an d terrestrial

- phase amphibians. Toxicity endpoint s used to calculate risk quotients are

the most sensitive for the taxa evaluated and are described in the tables showing the RQ values.

For e thephon applied at maximum applications rates on turf and ornamentals , the acute dose

based RQ values for birds ex ceed the LOC for acute risk to listed (RQ≥0.1) species for four or

### 46

more dietary items for all size classes ( Table 2 2 ). In addition, for turf , the acute dose

- based RQ

values for birds exceed the LOC for acute risk to non

- listed (RQ≥0.5) species for all size classes

of birds feeding on three types of dietary items ; no other registered uses have acute non

- listed

LOC exceedances for all size classes of birds for any dietary items . The chronic risk LOC

(RQ≥1) is exceeded for birds consuming short grass, ta ll grass, broadleaf plants/small insects , or

arthropods at the maximum label rate for all registered uses with the exception of peppers,

cherries, sugarcane, cantaloupes (TX only), pumpkin (hybrid seed production in IL only)

, wheat,

barley, and grapes

. Fo r use on turf, t he chronic risk LOC is exceeded for birds consuming every

dietary item, with RQs ranging from 1.75 for fruits and pods to 28 for short grass.

Table 2 2 . Acute and Chronic RQ for Birds Exposed to Ethephon as a Result of Registered

Use s

Food Type Acute Dose

- Based RQs 1 Subacute Dietary

RQs 2 Chronic

Dietary

- Based RQs 3 Small

(20 g) Medium

(100 g) Large

(1000 g)

National Maximum Label Rate for

Ornamentals: 2.8 lb s a.i./A, 1 application , Foliar

Short grass 1.78 * 0.80 * 0.25 0.13 6.34

Tall g rass 0.82 * 0.37 0.12 0.06 2.91

Broadleaf plants/small

insects 1.00 * 0.45 0.14 0.08 3.57

Fruits/pods/(seeds,

dietary only) 0.11 0.05 0.02 0.01 0.40

Arthropods 0.70 * 0.31 0.10 0.05 2.48

Seeds (granivore) 0.02 0.01 <0.01 N / A N / A

National Maximum Label Ra te for

Cotton, Tobacco, Apples, Berries, and Pineapple:

2 lbs a.i./A, 1 application , Foliar

Short grass 1.27 * 0.57 * 0.18 0.10 4.53

Tall grass 0.58 * 0.26 0.08 0.04 2.08

Broadleaf plants/small

insects 0.72 * 0.32 0.10 0.05 2.55

Fruits/pods/(seeds,

dieta ry only) 0.08 0.04 0.01 0.01 0.28

Arthropods 0.50 * 0.22 0.07 0.04 1.77

Seeds (granivore) 0.02 0.01 <0.01 N / A N / A

National Maximum Label Rate

for Tomatoes (including tomatoes for processing):

1.63 lbs a.i./A, 1 application , Foliar

Short grass 1.04 * 0. 46 0.15 0.08 3.69

Tall grass 0.48 0.21 0.07 0.04 1.69

Broadleaf plants/small

insects 0.58 * 0.26 0.08 0.04 2.08

Fruits/pods/(seeds,

dietary only) 0.06 0.03 0.01 <0.01 0.23

Arthropods 0.41 0.18 0.06 0.03 1.45

Seeds (granivore) 0.01 0.01 <0.01 N / A N / A

N ational Maximum Label Rate

for Tomatoes

- Fresh Market (CA only) and Walnuts:

1.25 lbs a.i./A , 1 application , Foliar

Short grass 0.80 * 0.36 0.11 0.06 2.83

Tall grass 0.36 0.16 0.05 0.03 1.30

### 47

Food Type Acute Dose

- Based RQs 1 Subacute Dietary

RQs 2 Chronic

Dietary

- Based RQs 3 Small

(20 g) Medium

(100 g) Large

(1000 g)

Broadleaf plants/small

insects 0.45 0.20 0.06 0.03 1.59

Fru its/pods/(seeds,

dietary only) 0.05 0.02 0.01 <0.01 0.18

Arthropods 0.31 0.14 0.04 0.02 1.11

Seeds (granivore) 0.01 <0.01 <0.01 N / A N / A

National Maximum Label Rate for

Peppers, Cherries, and Sugarcane :

1 lb a.i./A , 1 application , Foliar

Short grass 0 .64 * 0.29 0.09 0.05 2.26

Tall grass 0.29 0.13 0.04 0.02 1.04

Broadleaf plants/small

insects 0.36 0.16 0.05 0.03 1.27

Fruits/pods/(seeds,

dietary only) 0.04 0.02 0.01 <0.01 0.14

Arthropods 0.25 0.11 0.04 0.02 0.89

Seeds (granivore) 0.01 <0.01 <0.01 N / A N / A

National Maximum Label Rate for

Cantaloupes (TX only) :

0.75 lb a.i./A , 1 application , Foliar

Short grass 0.48 0.21 0.07 0.04 1.70

Tall grass 0.22 0.10 0.03 0.02 0.78

Broadleaf plants/small

insects 0.27 0.12 0.04 0.02 0.96

Fruits/pods/(seeds,

di etary only) 0.03 0.01 <0.01 <0.01 0.11

Arthropods 0.19 0.08 0.03 0.01 0.67

Seeds (granivore) 0.01 <0.01 <0.01 N / A N / A

National Maximum Label Rate for

Wheat, Barley, and Grapes :

0.5 lb a.i./A , 1 application , Foliar

Short grass 0.32 0.14 0.05 0.02 1.13

Tall grass 0.15 0.07 0.02 0.01 0.52

Broadleaf plants/small

insects 0.18 0.08 0.03 0.01 0.64

Fruits/pods/(seeds,

dietary only) 0.02 0.01 <0.01 <0.01 0.07

Arthropods 0.12 0.06 0.02 0.01 0.44

Seeds (granivore) <0.01 <0.01 <0.01 N / A N / A

National Maximum Label Rate for

Turf :

4 lbs a.i./A, 5 applications , 14

- day interval , Foliar

Short grass 7.89 * 3.53 * 1.12 * 0.59 * 28.05

Tall grass 3.61 * 1.62 * 0.51 * 0.27 12.86

Broadleaf plants/small

insects 4.44 * 1.99 * 0.63 * 0.33 15.78

Fruits/pods/(seeds,

dietary only ) 0.49 0.22 0.07 0.04 1.75

Arthropods 3.09 * 1.38 * 0.44 0.23 10.99

Seeds (granivore) 0.11 0.05 0.02 N / A N / A

Pumpkin (Hybrid seed production in IL only):

0.25 lb a.i./A, 6 application s, 7

- day interval , Foliar

Short grass 0.69 * 0.31 0.10 0.05 2.47

### 48

Food Type Acute Dose

- Based RQs 1 Subacute Dietary

RQs 2 Chronic

Dietary

- Based RQs 3 Small

(20 g) Medium

(100 g) Large

(1000 g)

Tall grass 0.32 0.14 0.05 0.02 1.13

Broadleaf plants/small

insects 0.39 0.17 0.06 0.03 1.39

Fruits/pods/(seeds,

dietary only) 0.04 0.02 0.01 <0.01 0.15

Arthropods 0.27 0.12 0.04 0.02 0.97

Seeds (granivore) 0.01 <0.01 <0.01 N / A N / A

Cucumber, Pumpkins, and S quash (Hybrid seed production in CA only):

0.25 lb a.i./A, 6 application s, 3

- day interval , Foliar

Short grass 0.83 * 0.37 0.12 0.06 2.94

Tall grass 0.38 0.17 0.05 0.03 1.35

Broadleaf plants/small

insects 0.47 0.21 0.07 0.04 1.66

Fruits/pods/(seeds,

die tary only) 0.05 0.02 0.01 <0.01 0.18

Arthropods 0.32 0.15 0.05 0.02 1.15

Seeds (granivore) 0.01 0.01 <0.01 N / A N / A

N / A=not applicable

Bolded values meet or exceed the Level of Concern (LOC) for acute risk to listed (RQ > 0.1) birds or chronic risk to

bi rds (RQ > 1).

* Bolded values with an asterisk meet or exceed the Level of Concern (LOC) for acute risk to non

- listed (RQ > 0.5)

birds

1 Acute dose

- based RQ values are based on the bobwhite quail LD 50 value of 596 mg ai/kg

- bw (MRID 00027493 )

.

2 Acute diet ary RQ values a re based on the bobwhite quail 8

- day LC 50 value of >5,000 mg a.i./kg diet (MRID

41080201 )

.

3 Chronic RQ values are based on the mallard NOAEC value of 106 mg a

. i

. /kg diet (MRID 49305605 )

.



### For maximum applications rates for use of ethephon on turf , the acute dose

- based RQ values for

all size classes of mammals exceed the LOC for acute risk to listed (RQ≥0.1) species for short

grass, tall grass, broadleaf plants/small insects , or arthropods ( Table 2 3 ). For maximum

applications rates for use of ethephon on ornamentals , the acute dose

- based RQ values for all

size classes of mammals exceed the LOC for acute risk to listed (RQ≥0.1) species for short grass

only

. There are no acute dose

- based LOC exceedances for peppers, cherries, sugarcane,

cantaloupes (TX only), pumpkin (hybrid seed production in IL only), wheat, barley, or grapes at

maximum application rates for these uses. No subacute dietary studies were available for

ethephon so no s ubacute dietary RQs were calculated . Chronic dietary RQs exceed the chronic

risk LOC of 1.0 for turf and ornamentals for at least three dietary classes. There are no c hronic

dietary LOC exceedances for peppers, cherries, sugarcane, cantaloupes (TX only), pumpkin

(hybrid seed pr oduction in IL only), wheat, barley, or grapes at maximum application rates for

these uses

.

Table 23 . Acute and Chronic RQ for Mammals Exposed to Ethephon as a Result of

Registered Use

Food Type Acute Dose

- Based RQs 1 Chronic

Dietary

- Based RQs 2 Small

( 15 g) Medium

( 35 g) Large

(1000 g)

National Maximum Label Rate for

Ornamentals: 2.8 lb s a.i./A, 1 application , Foliar

Short grass 0.24 0.21 0.11 2.24

### 49 Food Type Acute Dose

- Based RQs 1

Chronic

Dietary

- Based RQs 2 Small

( 15 g) Medium

( 35 g) Large

(1000 g)

Tall grass 0.11 0.09 0.05 1.03

Broadleaf plants/small

insects 0.14 0.12 0.06 1.26

Fruits/pods/(seeds, dietary

only) 0.02 0.01 0.01 0.14

Arthropods 0.09 0.08 0.04 0.88

Seeds (granivore) < 0.0 1 < 0.0 1 < 0.0 1 N / A

National Maximum Label Rate for

Cotton, Tobacco, Apples, Berries, and Pineapple:

2 lbs a.i./A, 1 application , Foliar

Short grass 0.17 0.15 0.08 1.60

Tall grass 0.08 0.07 0.04 0.73

Broadleaf plants/small

insects 0.10 0.08 0.04 0.90

Fruits/pods/(seeds, dietary

only) 0.01 0.01 <0.01 0.10

Arthropods 0.07 0.06 0.03 0.63

Seeds (granivore) <0.01 <0.01 <0.01 N / A

National Maximum Label Rate

for Toma toes (including tomatoes for processing):

1.63 lbs a.i./A, 1 application , Foliar

Short grass 0.14 0.12 0.06 1.30

Tall grass 0.06 0.06 0.03 0.60

Broadleaf plants/small

insects 0.08 0.07 0.04 0.73

Fruits/pods/(seeds, dietary

only) 0.01 0.01 <0.01 0.08

Arthropods 0.06 0.05 0.03 0.51

Seeds (granivore) <0.01 <0.01 <0.01 N / A

National Maximum Label Rate

for Tomatoes

- Fresh Market (CA only) and Walnuts:

1.25 lbs a.i./A , 1 application , Foliar

Short grass 0.11 0.09 0.05 1.00

Tall grass 0.05 0.04 0.02 0.4 6

Broadleaf plants/small

insects 0.06 0.05 0.03 0.56

Fruits/pods/(seeds, dietary

only) 0.01 0.01 <0.01 0.06

Arthropods 0.04 0.04 0.02 0.39

Seeds (granivore) <0.01 <0.01 <0.01 N / A

National Maximum Label Rate for

Peppers, Cherries, and Sugarcane :

1 lb a.i./A, 1 application , Foliar

Short grass 0.09 0.07 0.04 0.80

Tall grass 0.04 0.03 0.02 0.37

Broadleaf plants/small

insects 0.05 0.04 0.02 0.45

Fruits/pods/(seeds, dietary

only) 0.01 <0.01 <0.01 0.05

Arthropods 0.03 0.03 0.02 0.31

Seeds (granivore) <0.01 <0.01 <0.01 N / A

### 50 Food Type Acute Dose

- Based RQs 1

Chronic

Dietary

- Based RQs 2 Small

( 15 g) Medium

( 35 g) Large

(1000 g)

National Maximum Label Rate for

Cantaloupes (TX only) :

0.75 lb a.i./A, 1 application , Foliar

Short grass 0.06 0.06 0.03 0.60

Tall grass 0.03 0.03 0.01 0.28

Broadleaf plants/small

insects 0.04 0.03 0.02 0.34

Fruits/pods/(seeds, dietary

only) <0.01 <0.01 <0.01

0.04

Arthropods 0.03 0.02 0.01 0.24

Seeds (granivore) <0.01 <0.01 <0.01 N / A

National Maximum Label Rate for

Wheat, Barley, and Grapes :

0.5 lb a.i./A, 1 application , Foliar

Short grass 0.04 0.04 0.02 0.40

Tall grass 0. 02 0.02 0.01 0.18

Broadleaf plants/small

insects 0.02 0.02 0.01 0.23

Fruits/pods/(seeds, dietary

only) <0.01 <0.01 <0.01

0.03

Arthropods 0.02 0.01 0.01 0.16

Seeds (granivore) <0.01 <0.01 <0.01 N / A

National Maximum Label Rate for

Turf :

4 lbs a.i./A, 5 applications , 14

- day interval , Foliar

Short grass 1.07 * 0.91 * 0.49 9.91

Tall grass 0.49 0.42 0.22 4.54

Broadleaf plants/small

insects 0.60 * 0.51 * 0.28 5.58

Fruits/pods/(seeds, dietary

only) 0.07 0.06 0.03 0.62

Arthropods 0.42 0.36 0.19 3.88

Seeds ( granivore) 0.01 0.01 0.01 N / A

Pumpkin (Hybrid seed production in IL only):

0.25 lb a.i./A, 6 application s, 7

- day interval , Foliar

Short grass 0.09 0.08 0.04 0.87

Tall grass 0.04 0.04 0.02 0.40

Broadleaf plants/small

insects 0.05 0.05 0.02 0.49

Fruits /pods/(seeds, dietary

only) 0.01 0.01 <0.01 0.05

Arthropods 0.04 0.03 0.02 0.34

Seeds (granivore) <0.01 <0.01 <0.01 N / A

Cucumber, Pumpkins, and S quash (Hybrid seed production in CA only):

0.25 lb a.i./A, 6 application s, 3

- day interval , Foliar

Short gr ass 0.11 0.10 0.05 1.04

Tall grass 0.05 0.04 0.02 0.48

Broadleaf plants/small

insects 0.06 0.05 0.03 0.58

Fruits/pods/(seeds, dietary

only) 0.01 0.01 <0.01 0.06

Arthropods 0.04 0.04 0.02 0.41

Seeds (granivore) <0.01 <0.01 <0.01 N / A

### 51

N / A=not applicable

Bolded values meet or exceed the Level of Concern (LOC) for acute risk to listed (RQ > 0.1) mammals or chronic

risk to mammals (RQ > 1).

* Bolded values with an asterisk meet or exceed the Level of Concern (LOC) for acute risk to non

- listed (RQ > 0.5)

mamm als

1 Acute dose

- based RQ values are based on the laboratory rat LD 50 value of 1205 mg a.i

. /kg

- bw (MRID 00029509 ).

2 Chronic RQ values are based on the laboratory rat NOAEC value of 300 mg a.i./kg

- diet (MRID 41508701 ).



### 4.1.2.3. Terrestrial Invertebrate s

EECs for terrestrial invertebrates were calculated using the equations described in Section

3.2.3.4

. Ethephon is classified as practically non toxic to honey bee s on an acute contact and oral

exposure basis

. Since the acute oral and contact toxicity s tud ies for honey bee s exposed to

ethephon were non

- definitive ( i.e. , LD 50 

### s greater than highest concentration tested), RQs are not

calculated. The risk to insect pollinators is discussed in greater detail in the Risk Description

( Section 4.2 ).

4.1.2.4. Non

- target Terrestrial Plants

EECs for terrestrial plants were calculated using TERRPLANT (Version 1.2.2). RQ values for

terrestrial plants are calculated using the most sensitive endpoints for monocot and dicot species

in vegetative vigor and seedling e mergence tests with ethephon technical grade active ingredient

(T GAI ) ( Table 13 4 ). For all label uses of ethephon ( except for use on pumpkin, cucumber, and

squash ) , RQ values for monocot and dicot plants exposed to runoff exc eed the risk to non

- listed

and listed species LOC (LOC =1).

The potential for adverse effects to listed and non

- listed species of terrestrial and semi

- aquatic

plants from exposure to ethephon is discussed in greater detail in the Risk Descrip tion ( Section

4.2 ). In the risk description, the distance from the edge of the field where effects may occur due

to exposure to spray drift is described

.

Table 13 4 . RQs for Non

- target Terrestrial Plants Adjacent to Ethephon Use Sites

.

Use Plant Type Listed Status Risk Quotients

Dry Semi

- Aquatic

Turf (modeled application: 4 lbs a.i./A)

Monocot non

- listed 1.00 8.50

Monocot listed 2.18 18.55

Dicot non

- listed 0.75 6.42

Dicot listed 1.89 16.06

Ornamentals (modeled appli cation: 2.8 lbs a.i./A)

Monocot non

- listed 0.70 5.95

Monocot listed 1.53 12.98

Dicot non

- listed 0.53 4.49

Dicot listed 1.32 11.24

Cotton, Tobacco, Apples, Berries, and Pineapple (modeled application: 2 lbs a.i./A)

Monocot non

- listed 0.83 4.58

Monocot listed 1.82 10.00

Dicot non

- listed 0.63 3.46

### 52

Use Plant Type Listed Status Risk Quotients

Dry Semi

- Aquatic

Dicot listed 1.57 8.66

Tomatoes (including tomatoes for processing) (modeled application: 1.63 lbs a.i./A)

Monocot non

- listed 0.68 3.74

Monocot listed 1.48 8.15

Dicot non

- listed 0.51 2.82

Dicot listed 1.28 7.06

Tomatoes

- Fresh Market (CA only) and Walnuts (modeled application: 1.25 lbs a.i./A)

Monocot non

- listed 0.52 2.86

Monocot listed 1.14 6.25

Dicot non

- listed 0.39 2.16

Dicot listed 0.98 5.41

Peppers, Cherries, and Sugarcane (modeled application: 1 lb a.i./A)

Monocot non

- listed 0.42 2.29

Monocot listed 0.91 5.00

Dicot non

- listed 0.31 1.73

Dicot listed 0.79 4.33

Cantaloupes (TX only) (modeled application: 0.75 lb a.i./A)

Monocot non

- listed 0.31 1.72

Monocot listed 0.68 3.75

Dicot non

- listed 0.24 1.30

Dicot listed 0.59 3.25

Wheat, Barley, and Grapes (modeled application: 0.5 lb a.i./A)

Monocot non

- listed 0.21 1.15

Monocot listed 0.45 2.50

Dicot non

- listed 0.16 0.86

Dicot listed 0.39 2.17

Pumpkin (Hyb rid seed production in IL only) and Cucumber, Pumpkins, and Squash

(Hybrid seed production in CA only) (modeled application: 0.25 lb a.i./A)

Monocot non

- listed <0.1 0.53

Monocot listed 0.14 1.16

Dicot non

- listed <0.1 0.40

Dicot listed 0.12 1.00

B old values indicate LOC (1.0) exceedence

* Runoff RQ values for non t arget plants are based on the seedling emergence NOAEC of 0.11 lb a.i./A for monocots

and 0.127 lb a.i./A for dicots

. C orresponding I C 25 values were estimated to be 0.24 lb a.i./A for monoc ots and 0.32

lb a.i./A for dicots . The most sensitive NOAEC for vegetative vigor is 0.13 lb a.i./A for monocots and 0.00042 lb

a.i./A for dicots.



### 4. 2. Incident Database Review

The Ecological Incident Information System (EIIS)

, which is maintained by the Agency’s Office

of Pesticide Programs, was searched to determine if ecological incidents have been reported for

ethephon . Based on a search of EIIS conducted in July 2015, t here are eight incident s in the EIIS

database associated with ethephon

. Of th e eight incidents, six allege crop damage following

application. Three incidents are associated with barley crop damage ( I010934

- 010 ; I016662

- 029; I017865

- 030 ); one is associated with grape crop damage ( I014426

- 010 ); one is associated

### 53

with rye crop damage ( I021411

- 019 ) ; and one is associated with spring wheat crop damage

( I016912

- 018 ). Of the two remaining incidents, one ( B0000

- 500

- 14 ) is a farm pond fish kill that

occurred following application of ethephon

, malathion

, and merphos to nearby cotton, and the

other involved horses that became ill after entering a treated pasture ( I024576

- 001 ).

 Incident# B0000

- 500

- 14 occurred in Brooks County, GA in October 1989. Malathion (PC

code 057701), merphos (PC code 074901) and ethephon were aerially applied adjacent to a

pond at rates of 1, 1 and 1.5 pt/A, respectively. W ater sampling approximately two weeks

after the applications detected malathion at 0.18 ppb. Malathion had been sprayed as part of

the program to eradicate the boll weevils on cotton and t he certai nty index for this incident

indicated that it was probable that malathion was most likely responsible for the fish kill

. The certainty of ethephon contributing to this incident was designated possible.

 Incident# I010934

- 010 occurred in 2000 in Teton, ID. This incident reported plant damage

in 360 A of barley fields directly sprayed with ethephon contained in Cerone  

### (39.9% a.i.).

Cerone  

### was broadcast at 0.66 pt/A as a registered use. It was assumed that the product was

responsible for the damage and t he certainty index of the incident was reported as probable.

 Incident# I014426

- 010 occurred in 2003 in Kern County , CA. This incident reported crop

drop and loss in 78 A of grape crops (vineyard) treated directly with 1 pint/A of Ethrel 



### (21.7% a.i.). E ffects were observed in 100% of the plants, but the entire crop was not lost.

The application was made with high temperatures and improper timing. The registrant,

Bayer CropScience, reported that the symptoms were related to Ethrel  

### ; the certainty index

was possible.

 Incident# I016662

- 029 occurred in 2005 in Burleigh County , ND. This incident reported leaf

burn and leaf loss in 65 A of barley fields directly treated with ethephon. Cerone  

### (39.9%

a.i.; Registration #264

- 377) was applied aerially at 8 oz /A. At the time of application,

temperatures were very high, which was against the directions of that label and was thus, a

misuse of this product. The certainty index of this incident was probable.

 Incident# I016912

- 018 occurred in 2005 in Henry County , ID. This incident reported

stunting of 60 A of spring wheat treated directly with Cerone  

### (39.9% a.i.). Cerone  

### plant

regulator was applied at 0.66 pint/A by ground spray under registered use. The certainty

index was classified as possible, but it was unclear why the effects occurred.

 Incident# I017865

- 030 occurred in 2006 in Montana. This incident reported yellowing of

540 acres of barley treated directly with Cerone  

### at 7 oz/A. The certainty index was

classified as probable.

 Incident# I02 1411

- 019 occurred in October 2009 in Halifax County, NC. This incident

reported a phototoxic reaction from an application of the products Dropp SC ( 1.5 pint/acre;

a.i. thiadiazuron) and Finish Pro ( 2.4 oz/acre; a.i. cyclanilide and ethephon) onto 75 acres of

rye in Halifax County, NC. The rye was allegedly desiccated by the application throughout

100% of the field. The certainty index was classified as possible.

### 54

 Incident# I024576

- 001 occurred in October 2012 in Parker County, TX. It was reported that

ethephon was applied to a field by an aerial applicator several days before several horses

became ill after going into the pasture. The certainty of this incident was classified as

possible.

Based on a search of the U.S. EPA Office of Pesticide Programs Incident Data System (IDS),

which compiles aggregate incidents, only one incident involving ethephon was found. This

incident (016573

- 00081) was for minor plant damage associated with Ethrel ® 

### soluble

concentrate occurring between April and June of 2005

.

A lack of reported incidents does not necessarily mean that incidents have not occurred. In

addition, incident reports for non

- target plants and animals typically provide information on

acute mortality events only. Reports for other adverse effects, such as reduc ed growth or

impaired reproduction, are rarely received. Available incident information indicates that

registered use s of ethephon have the potential to result in adverse effects to terrestrial plants and

animals

.

4.3

. Risk Description

This prelim inary risk assessment of the labeled uses of ethephon relies on the deterministic RQ

method to provide a metric of potential risks. RQs for some registered ethephon uses exceed

LOC values for :

 birds (acute listed, acute non

- listed , and chronic risk LOCs) ;

 mammals (acute listed, acute non

- listed , and chronic LOCs) ;

 listed aquatic vascular plants; and,

 terrestrial plants (listed and non

- listed)

T oxicity data available for adult honey bee s suggest that LOCs wo uld not be exceeded on an

acute oral or contact basis.

4.3 .1 Risk to Aquatic Organisms

Aquatic Exposure

Surface water EECs resulting from applications of ethephon are estimates of exposure for the use

of ethephon as a plant growth regulator. Application practices were modeled using the

maximum annual application rates. Environmental fate data were conservatively represented in

keeping with EFED’s Input Parameter Guidance

(http://www.epa.gov/oppefed1/models/water/input_parameter_guidance.htm) by using an

uncertainty factor of 3X applied to the single s oil and sediment metabolism half

- life estimates.

Finally, scenario selection was conservatively performed by modeling runoff prone soils that

drain to a small pond without an outlet.

Aquatic Animals

R isk to freshwater and estuarine/marine fish and inve rtebrates is well below the established acute

and chronic levels of concern and adverse effects to aquatic animals are not anticipated to result

from registered uses of ethephon. Although there is one aquatic animal incident associated with

### 55

ethephon in th e EIIS database , this incident was more likely caused by the malathion rather than

ethephon applied

.

Aquatic Plants

Based on available data, t he likelihood for adverse effects to listed and non

- listed vascular and

nonvascular aquatic plants is considered low

. RQ values for non

- listed vascular and listed and

non

- listed non vascular aquatic plants range from < 0.0 1 to 0.01. RQ values for listed vascular

aquatic plants range from 0.24 to 1 .2 3 . The aquatic modelling scenarios having exposures higher

than the vascular aquatic plant toxicity endpoint

— thereby resulting in risk exceeding the LOC

of 1.0

— are FL tomato (RQ=1.35) and FL turf (RQ=1.00 ). T here is some uncertainty with this

conclusion of adverse effects to listed vascular aquatic plants because the to xicity endpoint is an

EC 05 

### rather than a NOAEC, since s tatistically sig nificant effects were observed at all

concentrations tested (19% growth reduction compared to the control in the lowest treatment)

. T he lowest concentration tested was 0.10 mg a.i./L , b ut the EC 05 

### was determined to be

approximately an order of magnitude smaller than this concentration (0.017 mg a.i./L).

Therefore, since a NOAEC of 0.024 mg a.i./L would eliminate risk exceeding the LOC for

aquatic vascular plants, additional data establis hing a NOAEC only 0.00 7 mg a.i./L higher than

the current EC 05 

### w ould change risk conclusions

.

4.3.2. Risk to Terrestrial Organisms

Terrestrial Exposure

To evaluate the potential for terrestrial exposure from the multiple registered use s of ethephon

, appli cation practices were modeled by using maximum application rates. Exposure was

estimated using upper

- bound Kenaga values from T

- REX version 1.5.2. T he spray drift model

AgDrift version 2.1.1 provide s helpful bounds which define the spatial extent of risk concern

resulting from off

- field drift at currently registered ethephon application rates.

Birds and Mammals

Ethephon is categorized as slightly toxic to birds on an acute oral exposure basis. On a subacute

dietary basis, ethephon is categorized as pr actically non

- toxic. Ethephon is categorized as

slightly toxic to mammals on an acute oral exposure basis.

In this assessment, RQ s based on acute oral exposure to birds exceed the acute risk to listed

species LOC of 0.1 and acute risk to non

- listed spe cies LOC of 0.5 for at least four of the dietary

classes for small birds at maximum application rates

. Risk to n on

- listed species LOCs are

exceeded for small birds foraging on short grass at maximum labeled rates for all uses except

cantaloupes

, wheat, ba rley, and grapes. Risk to non

- listed species LOCs are exceeded for three

dietary classes for small, medium , and large

- sized birds for turf at maximum label e d rates. RQs

calculated based on a sub acute dietary exposure to birds exceed LOCs for risk to list ed birds

foraging on short grass at the maximum label rates for ornamentals, cotton, tobacco, apples,

berries, and pineapple

. RQs calculated based on a subacute dietary exposure to birds exceed

LOCs for risk to listed birds foraging on tall grass, broadle af plants/small insects, and

arthropods, and listed and non

- listed birds foraging on short grass at the maximum label rate for

turf

.

### 56

RQs for birds based o n chronic dietary exposure exceed the chronic risk LOC for birds

consuming short grass, tall grass, broadleaf plants/small insects, and arthropods at the maximum

label rate for all registered uses with the exception of peppers, cherries, sugarcane, cantaloupes

(TX only), pumpkin (hybrid seed production in IL only), wheat, barley, and grapes (RQs for

the se uses, at application rates ranging from 0.25 lb a.i./A to 1 lb a.i./A, exceed the avian chronic

risk LOC for one to three dietary categories . For use on turf, the chronic risk LOC is exceeded

for birds consuming every dietary item, with RQs as high as 28 for foragers consuming short

grass. Avian reproduction testing with mallard found a significant reduction in hatchlings (24%

reduction compared to the control) and hatchling survival per eggs set (25% reduction compared

to the control) at the 300 mg a.i ./kg diet treatment level compared to the control; however, no

significant reductions for the parameters of number of hatchlings and hatchling survival per eggs

set (2% reduction compared to the control for both number of hatchlings and hatchling survival)

were seen in the 955 mg a.i./kg diet treatment. Therefore, the NOAEC used to estimate avian

chronic RQs is conservatively established at 106 mg a.i./kg diet , since it is uncertain whether the

reductions were toxicant mediated, the result of a greater pro portion of sensitive birds in the 300

mg a

. i

. /kg diet treatment, or related to husbandry

.

For maximum applications rates for use of ethephon on turf , the acute dose

- based RQ values for

all size classes of mammals exceed the LOC for acute risk to listed (R Q≥0.1) species for short

grass, tall grass, broadleaf plants/small insects , or arthropods

. For maximum applications rates

for use of ethephon on ornamentals, the acute dose

- based RQ values for all size classes of

mammals exceed the LOC for acute risk to l isted (RQ≥0.1) species for short grass only

. There

are no acute dose

- based LOC exceedances for peppers, cherries, sugarcane, cantaloupes (TX

only), pumpkin (hybrid seed production in IL only), wheat, barley, or grapes at maximum

application rates for thes e uses. No subacute dietary studies were available for ethephon so no

subacute dietary RQs were calculated. Chronic dietary RQs exceed the chronic risk LOC of 1.0

for turf and ornamentals for at least three dietary classes. There are no c hronic dietary LOC

exceedances for peppers, cherries, sugarcane, cantaloupes (TX only), pumpkin (hybrid seed

production in IL only), wheat, barley, or grapes at maximum application rates for these uses

(ranging from 0.25 lb a.i./A to 1 lb a.i./A)

.

Laboratory rats fed di ets containing ethephon (3000 mg a.i./kg

- diet) had significant bodyweight

and food consumption reductions relative to controls. Dietary EECs range from 1 ,362 to 2,973

mg/kg

- diet for maximum label rates and are lower than the LOAEC. Standard RQs are

calcu lated based on upper

- bound K enaga values. When considering EECs based on mean

K enaga exposure estimates and the maximum application rate for turf , chronic dietary RQs for

mammals are approximately 66% less than RQs associated with the upper

- bound Kenaga v alues.

Chronic LOC exceedances remain for mean Kenaga exposure estimates for the turf use pattern;

however, the magnitude of the exceedances is lesser

.

The potential for risk to birds and mammals from proposed foliar uses were evaluated in this

assessment using the default foliar dissipation half

- life of 35 days, since no additional data w ere

available to determine the decline in ethephon residues in dietary items. However, since LOCs

for acute risk to listed (RQ≥0.05) and non

- listed (RQ≥0. 1) birds and chronic risk (RQ≥1) to

mammals are exceeded in this assessment, the impact of different half

- lives on RQs was

examine d for purposes of characterization ( Table 14 5 ). Based on this analysis, at maximum

### 57

labeled application rates, both acute and chronic risk LOCs are exceeded even when a half

- life of

1 day is considered. Additionally, at maximum label rates and assuming the defaul t 35 day foliar

dissipation rates, LOCs are exceeded for 7 to more than 56 days. Therefore, potential risks of

concern to birds and mammals from labeled use s of ethephon would not be precluded based on

refinements to the default foliar dissipation half

- li fe.

Table 14 5

. Impact of Different Foliar Dissipation Half

- lives on the Number of Days RQs

Based on Dietary Exposure Exceed LOCs.

Application Rate

(lbs a.i./A) Number of Days T here is a D ietary LOC exceedance 1

Avian Mammalian

Acute Chronic Acute Chronic

35 day foliar dissipation rate

4 (5 applications, 14

- d interval) 56 56 56 56

1 56 42 0 56

0.5 56 7 0 40

0.25 ( 6 applications,

7

- d interval) 56 45 0 54

0.25 (6 applications,

3

- d interval) 56 53 6 56

1 day foliar dissipatio n rate

4 (5 applications, 14

- d interval) 20 16 8 20

1 3 2 0 3

0.5 2 1 0 2

0.25 (6 applications,

7

- d interval) 6 0 0 6

0.25 (6 applications,

3

- d interval) 6 0 0 6

1 The analysis is only carried out to a maximum of 56 days based on limitations in T

- REX

.



### T he STIR model output indicates that inhalation of ethephon is not likely to be a significant

exposure pathway of concern for avian and mammalian species.

The SIP model output indicates that drinking water exposure alone is considered a potential

pat hway of concern for birds or mammals on an acute and chronic exposure basis. However, the

model employs a number of conservative assumptions to derive upper bound exposure estimates,

the most important of which being how it equates the concentration of ch emical in drinking

water to the solubility of the chemical in water. Since ethephon is highly soluble (1.24 x 10 6



### mg/L), the drinking water concentrations estimated by SIP are far higher than would conceivably

be found in a puddle following application.

Terrestrial Invertebrates

In a 48

- hour acute oral and contact toxicity test in which young adult honey bees were exposed

to ethephon

, t here was 7 % mortality observed at 58.5 μg a.i./bee in the oral toxicity assay, and

no mortality in the contact toxicity a ssay

. The NOAELs for the oral and contact tests were 116.5

and 100 μg ai/bee, respectively. The LC 50 

### value for the oral test was >116.5 μg ai/bee . The

LD 50 

### value for the contact test was >100 μg ai/bee

. Based on th ese limited data, e thephon is

categori zed as practically nontoxic to honey bees on an acute oral and contact basis . The acute

### 58

dietary exposure EEC s for tall grass range from 0.68 to 10.8 μg a.i./bee/day

, the highest ratio of

the EEC to the highest level tested in the contact toxicity assay ( 1 0.8/100

= 0.11 ) is l ess than the

acute risk LOC (0.4) for individual bees.

Since ethephon is used on cotton and and other insect pollinator

- attractive crops used by some

beekeepers to produce honey, the proximity of bee colonies to ethephon use areas ma y be high

. C otton specifically is an in de te rminate blooming crop, i.e. , blooms over a protracted period of

time , which increases the potential timeframe for exposure

. Ethephon is taken up into plants ;

however , it is unknown whether it is transported in t he xylem and phloem and whether bees may

be exposed to ethephon taken up into plant materials such as pollen, nectar, etc.

There are no reported incidents of bee kills for ethephon . However, the absence of bee kill

incident data cannot be construed as the absence of incidents.

Based on the acute oral and contact toxicity studies , risk to individual adult honey bee s would be

considered low; however, a full dataset is not available to fully evaluate risk to honey bee s (i.e.,

chronic oral toxicity to ad ults and acute and chronic toxicity to larvae) . Pollinator risk

assessment guidance has recently been finalized and recommends the following honey bee data

be available for a Tier I screening level

risk assessment for honey bee s:

 acute oral toxicity to a dult honey bee s ;

 acute oral toxicity to larval honey bee s ;

 chronic oral toxicity to adult honey bee s ; and

,

 chronic oral toxicity to larval honey bee s.

Acute oral toxicity data for adult honey bees are available and no effects were seen at an

acceptable li mit dose; however, i f the other Tier I studies identify the potential for a risk concern,

additional studies may be requested

.

Until these data are available, the risk to honey bee s cannot be fully evaluated. Risk to

individual adult honey bee s exposed in the ir diet to ethephon could not be evaluated.

Additionally, data are not available to evaluate potential eff ects to brood.

Non

- target terrestrial plants

Based on the available registrant

- submitted toxicity data, RQs exceed the Agency’s LOC for risk

to terrestrial plants ( Table 13 4 ). Application of technical grade ethephon at rates of up to 2.1 lb

a.i./acre resulted in statistically significant (p<0.05) reductions in shoot length for cucumber

( Cucumis sativus ) in vegetative vigor testing at treatment rates as low as 0.008 lb a.i./acre ( EC 05



### = 0. 000418 lb a.i./A) and shoot length for corn ( Zea mays ) in vegetative vigor testing at

treatment rates as low as 2.1 lb s a.i./acre ( NOAEC = 0. 127 lb a.i./A)

. This indic ates that there is

potential for effects to non

- target plants at the maximum labeled rates. Assuming an aerial

application, ASAE fine to medium drop size distribution, and 0.5 lb a.i./A application rate,

exposure at 0. 0106 lb a.i./A (the vegetative vigor dicot IC 25 

### ) would occur up to 43 3 feet from the

edge of the field

. Aerial application rates greater than or equal to 1 lb a.i./A would require a

spray drift buffer greater than 997 feet to protect sensitive non

- target plants. Based on available

data, a 7 19

- foot spray drift buffer for aerial applications of ethephon at 0.75 lb a.i./A, and a 435

-

### 59

foot spray drift buffer for aerial applications of ethephon at 0.5 lb a.i./A would be protective of

sensitive non

- target plants.

Six terrestrial plant incident s in the EIIS database are associated with ethephon : Three incidents

are associated with barley crop damage ( I010934

- 010; I016662

- 029; I017865

- 030 ); one is

associated with grape crop damage ( I014426

- 010 ); one is associated with rye crop damage

( I021411

- 019 ); and one is associated with spring wheat crop damage ( I016912

- 018 ). The

certainty of each terrestrial plant incident in EIIS was categorized as either possible or p robable.

A search of the U.S. EPA Office of Pesticide Programs Incident Data System (IDS ) identified

one additional aggregate incident involving ethephon . This incident (016573

- 00081) was for

minor plant damage associated with Ethrel ® 

### soluble concentrate occurring between April and

June of 2005

. B ased on the fact that ethephon is a known plan t growth regulator having a

mechanism of action that co uld result in effects to plants, t he EIIS and IDS incidents corroborate

the potential for ethephon to dir ectly affect terrestrial plants

.

Terrestrial Spray Drift Distance

It is useful to know how far from the edge of the field spray drift exposure alone could result in

risk to terrestrial organisms. S pray drift exposure to ethephon was determined using AgDRIFT

version 2.1.1 (USEPA, 2013) . The terrestrial spray drift distance was determined using Tier I

Ground and Tier I Aerial terrestrial point deposition estimates using a fraction of applied based

on the acute

- dose based RQ for birds and the acute listed and acute non

- listed LOC. The default

ASAE Fine to Medium droplet size distribution was assumed for aerial applications. For ground

applications, a high boom, ASAE very fine to fine drop size distribution, and the 90 th 

### data

percentile was assumed. These are the default spray drift inputs recommended for modeling

spray drift (USEPA, 2013)

.

The acute

- dose based RQ value combined with the acute risk to listed and acute risk to non

- listed

species LOC s , results in the greatest spray drift distance for terrestrial organisms. The terrestrial

spray drift distance ( i.e ., the distance from the edge of the fie ld where spray drift exposure could

result in RQs that exceed LOC s ) for acute and chronic risk to listed and non

- listed birds was

explored for the turf use pattern (the highest registered application rate for ethephon) and for

cotton, tobacco, apples, berr ies, and pineapple (the highest registered aerial application rate for

ethephon) and other select application rates ( Table 27 )

. For ground applications to turf , the

spray drift buffer distance s range from three feet to 190 feet from the edge of the field for listed

birds

. On a chronic basis , the spray drift distances range from seven to 72 feet for the turf use

pattern for birds

. For listed species, the buffer distance for aerial applications to cotton, tobacco,

apples, berries, and pineapple range from zero to 121 feet for birds

. On a chronic basis, the spray

drift distances range from zero to 26 feet for the cotton / tobacco / apples / berries/pineapple use

pattern for birds. The terrestrial spray drift distance estimated for birds is protective of other

te rrestrial organisms (e.g., mammals, reptiles, terrestrial phase amphibians) from effects due to

exposure to spray drift since avian toxicity endpoints are the lowest of tested terrestrial animals

. The use of drift reduction technology (DRT) could reduce t he distance necessary to prevent

exceedances of the LOC but DRT is not currentl y required on ethephon labels.

Table 27. Spray Drift Distance Where Avian RQs do not Exceed Acute and Chronic LOCs

### 60

Application Rate (lbs a.i./A) Distance to no LOC exceedanc e (feet) *

Avian

Acute Chronic

20 (ground application) Listed: 190

Non

- listed: 43 72

2 .8 (ground application) Listed: 45

Non

- listed: 10 20

2 (aerial application) 121 26

1 (ground application) Listed: 20

Non

- listed: 3 7

0.5 (ground application) Liste d: 10

Non

- listed: 0 3

*Results generated by AgDRIFT



### The terrestrial spray drift distance ( i.e ., the distance from the edge of the field where spray drift

exposure could result in RQs that exceed LOCs) for risk to non

- listed terrestrial plants was

explor ed for the turf use pattern (the highest registered application rate for ethephon) and for

cotton, tobacco, apples, berries, and pineapple (the highest registered aerial application rate for

ethephon) ( Table 28 )

.

Table 2 8 . Spray Drift Distance Where Ter restrial Plant RQs do not Exceed LOCs

Application Rate (lb a.i./A) Distance to no LOC exceedanc e (feet)*

Terrestrial Plant

Monocot Vegetative Vigor

Zea mays IC 25 = 2.1 lb a.i./A Dicot Vegetative Vigor

Cucumis sativus IC 25 =0.0106 lb a.i./A

Ground appli cation

4 7 659

2.8 3 515

2 3 400

1

-- ** 226

0.75

-- ** 174

0.5

-- ** 118

0.25

-- ** 59

Aerial application

2

-- ** >997

1

-- ** >997

0.75

-- ** 719

0.5

-- ** 433

*Results generated by AgDRIFT

**Off

- site exposure resulting from spray drift is les s than toxicity threshold for this comparison



### 4.4

. Uncertainties and Data Gaps

4.4 .1. Fate and Transport

The studies submitted to fulfill environmental fate data requirements for ethephon are sufficient

to conduct an exposure assessment.

### 61

T

- REX EECs ar e based on residues on surfaces of dietary items. Ethephon is taken up into

leaves and it is uncertain whether ethephon is taken up by roots and/or distributed in xylem

and/or phloem. Exposure based on this exposure route was not assessed.

4.4 .2. Effe cts

Pollinator risk assessment guidance has recently been finalized and recommends a suite of

laboratory

- based studies extending beyond the acute contact study with adult bees.

As these data are currently unavailable for ethephon

, the potential risk to individual honey bee s

and brood success could not be fully assessed

.

5. Endocrine Disruptor Screening Program (EDSP)

Ethephon was not included in the first group of 67 chemicals issued an order to conduct Tier 1

EDSP testing. For additional information on the EDSP, visit http://www.epa.gov/endo/

.

6

. Federally Threatened and Endangered (Listed) Species Concerns

In November 2013, the EPA, along with the U.S. Fish & Wildlife Service (USFWS), the

National Marine Fi sheries Service (NMFS) (collectively, the Services) , and the U.S. D epartment

of Agriculture (USDA) released a summary of their joint Interim Approaches for assessing risks

to listed species from pesticides. The Interim Approaches were developed jointly by the

a g encies in response to the N ational A cademy of S ciences’ (NAS) recommendations and reflect

a common approach to risk assessment shared by the a gencies as a way of addressing scientific

differences between the EPA and the Services. The NAS report outlines recommendations on

specific scientific and technical issues related to the development of pesticide risk assessments

that EPA and the Services must conduct in connection with their obliga tions under the

Endangered Species Act (ESA) and FIFRA

.

The joint Interim Approaches were released prior to a stakeholder workshop held on November

15, 2013. In addition, the EPA presented the joint Interim Approaches at the December 2013

P esticide P rog ram D ialogue C ommittee (PPDC) and S tate

- FIFRA Issues Research and

Evaluation Group ( SFIREG ) meetings, and held a stakeholder workshop in April 2014, allowing

additional opportunities for stakeholders to comment on the Interim Approaches. As part of a

phas ed, iterative process for developing the Interim Approaches, the agencies will also consider

public comments on the Interim Approaches in connection with the development of upcoming

Registration Review decisions. The details of the joint Interim Approach es are contained in the

white paper “ Interim Approaches for National

- Level Pesticide Endangered Species Act

Assessments Based on the Recommendations of the National Academy of Sciences April 2013

Report ,” dated November 1, 2013.

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

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

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

### 62

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

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

specific species or habitat s, for this preliminary assessment EPA conducted a screening

- level

assessment for all taxa of non

- target wildlife and plants that assumes for the sake of the

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

the application of ethephon . This preliminary risk assessment will allow EPA to focus its future

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

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

- level risk

assessment for ethephon indicates potential risks of direct effects to listed dicot terrestrial plan ts,

monocot terrestrial plants

, aquatic vascular plants, mammals, birds , and terrestrial invertebrates

for registered ethephon u se sites . Listed species of semi

- aquatic plants may also be affected

through indirect effects because of the potential for direct effects on listed and non

- listed species

upon which such species may rely. Potential direct effects on listed dicot terrestr ial plants,

monocot terrestrial plants, aquatic vascular plants, mammals, birds, and terrestrial invertebrates

from the use of ethephon may be associated with modification of Primary Constituent Elements

(PCEs) of designated critical habitats, where such d esignations have been made. O nce the

agencies have fully developed and implemented the scientific methods necessary to complete

risk assessments for endangered and threatened (listed) species and their designated critical

habitats, these methods will be a pplied to subsequent analyses for ethephon as part of completing

this registration review.

Table 15 9

. Preliminary Conclusions for Potential Direct Effects to Federally Listed Taxa

Associated with the Registered Uses of Ethephon

.

Listed Plant Taxon Potential Direct Effects

Terrestrial and semi

- aquatic plants

–

monocots and dicots Yes

Aquatic vascular plants Yes

Aquatic non

- vascular plants No

Listed Animal Taxon Potential Direct Effects

Acute Chronic

Terrestrial invertebrates Uncertain: No toxicity data for

larval bees Uncertain: No chronic toxicity

data for adult or larval honey

bees

Mammals Yes Yes

Birds

Yes Yes Reptiles

Amphibians

Freshwater fish No No

Freshwater invertebrates No No

Mollusks No No data

Estuarine /marine fish No No

Estuarine/marine invertebrates No No

### 63

7

. Conclusions

The risk hypothesis identified in the problem formulation stated

,

Given the currently labeled uses of ethephon and its environmental fate properties, there

is a likelihood of expo sure to non

- target terrestrial and aquatic organisms.

When used in accordance with the label, ethephon may result in potential adverse effects

upon the survival, growth, and reproduction of non

- target terrestrial and aquatic

organisms.

After reviewin g the most recent environmental fate and effects data for ethephon , the preliminary

risk assessment concludes that registered uses of the plant growth regulator ethephon may result

in risks to both listed and non

- listed species of birds, mammals, and terre strial plants and listed

aquatic vascular plants

.

With respect to exposure, ethephon is characterized as nonvolatile, soluble compound that is

slightly t o moderately mobile in soil. Ethephon dissipates in the environment through both biotic

and abiotic degradation and by leaching in soils that are low in organic carbon. Therefore, there

is slight potential for ethephon to accumulate in soil with repeated applications. Surface water

contamination may also occur due to spray drift and/or transport of resi dues sorbed to sediment

in runoff ( i.e , erosion). In either aquatic or terrestrial environments, ethephon is not expected to

bioaccumulate due to its low K

ow



### .

The available data indicate that ethephon is slightly toxic to freshwater fish and freshwater a nd

estuarine/marine invertebrates on an acute exposure basis. Effects on fry hatching success were

observed in the available chronic freshwater fish study

. Chronic effects to a dult length were

observed in the available chronic freshwater invertebrate tes ting . Effects on survival were

observed in testing with vascular aquatic plant s, and inhibited growth was observed when

nonvascular aquatic plants were exposed to ethephon

.

The available data indicate that ethephon ranges from practically non

- toxic to slightly toxic to

birds, including passerines, and is slightly toxic to mammals on an acute oral exposure basis and

highly toxic to mammals on an subacute

- dietary exposure basis. Ethephon is practically non

toxic to young adult honey bees on an acute oral and contact exposure basis

.

The available data for terrestrial plants exposed to technical e thephon for formulation into end

use products (71.9

- 73.8% a.i. ) indicate that ethephon exposure to seeds and/or emerging plants

( i.e. , seedling emergence) can eff ect significantly reduced plant height at application rates

equivalent to 0. 22 lb a.i./A compared to the control while exposure to foliage ( i.e. , vegetative

vigor) can effect significantly reduced plant height at application rates equivalent to 0.00 8 lb

a. i./A compared to the control

.

There is a potential for direct adverse effects to the following taxa based on LOC exceedances :

 Mammals (acute listed, acute non

- listed , and chronic risk LOCs exceeded)

 Birds

, terrestrial

- phase amphibians

, and reptiles (acu te listed, acute non

- listed , and

### 64

chronic risk LOCs exceeded)

 Aquatic vascular plants ( listed species LOC exceeded for three ethephon use patterns)

 Terrestrial plants

Limited available toxicity data for honey bee s suggest that acute risk LOCs are not excee ded on

an acute contact or oral basis; however, data are not available to evaluate potential for effects to

individual bees and their brood exposed via the diet.

8. R eferences

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of Pesticide Regulation, Surface Water Protection Program. Available at:

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degradation in soil. Pages 135

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Urban, D. J., & Cook, N. J. 1986. Ecological Risk Assessment . EPA 540/9

– 85

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USEPA. 1992. Reregistration Eligibility Decision (RED): Eth ylene. United States

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Substances. Online at: http://nepis.epa.gov/Adobe/PDF/90110700.PDF

USEPA. 1992a. Pesticides in Ground Water Database: A Compilation of Monitoring Studies:

1 971

- 1991 : National Summary. United States Environmental Protection Agency,

Washington DC.

USEPA. 199 5 . Reregistration Eligibility Decision (RED): Ethephon . United States

Environmental Protection Agency, Office of Prevention, Pesticides, and Toxic

Sub stances. Online at: http://www.epa.gov/pestici des/reregistration/REDs/0382.pdf

USEPA. 1998. Guidelines for Ecological Risk Assessment . EPA/630/R

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Assessment Forum. Office of Research and Development. U.S. Environmental

Protection Agency. A vailable at http://www.epa.gov/raf/publications/guidelines

ecological

- risk

- assessment.htm (Accessed November 7, 2012).

USEPA. 2002. Morton, T.G. Minutes of the HED Ethephon Risk Assessment Team Meeting of

4/25/02 discussing the hydroxy metabolite in water and poultry metabolism studies.

Chemical No. 099801. Barcode D282695. United States Environmental Protection

Agency, Office of Pesticide Programs, Health Eff ects Division; Memorandum of

Conference. May 28, 2002.

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, United States Environmental Protection Agency (USEPA) (pp. 100).

Washington, D.C.: Government Prin ting Office. Available at

http://www.epa.gov/espp/consultation/ecorisk

- overview.pdf (Accessed June 19, 2009).

### 65

USEPA. 2004b. Overview of the Ecological Risk Assessment Process in the Office of Pesticide

Programs . Environmental Fate and Effects Division. Office of Pesticide Programs. U.S.

Environmental Protection Agency. Available at

http://www.epa.gov/espp/cons ultation/ecorisk

- overview.pdf (Accessed June 19, 2009).

USEPA. 2006. Environmental Fate and Ecological Risk Assessment for the Registration of New

Uses of Ethephon . DP Barcode no. 324040. September 14, 2006.

USEPA. 2006a. Drinking Water Data & Databases. United States Environmental Protection

Agency. Available at: http://www.epa.gov/safewater/databases.html.

USEPA. 2009

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, United States Environmental Protection Agency

(USEPA) . Available at http://cfpub.epa.gov/ecotox/

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Barcode 371952. April 19, 2010. Environmental Fate and Eff ects Division. Office of

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USEPA. 2011. Evaluation for Ecological Toxicity Data in Open Literature . May 9, 2011.

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Chemical Safety and Pollution Prevention. U.S. Environmental Protection Agency.

Available at

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pecies_reregistration_workgroup/esa_evaluation_open_literature.htm (Accessed April 3,

2015).

USEPA. 2012. Screening Level Usage Analysis (SLUA) of Ethephon (099801). U.S.

Environmental Protection Agency, Office of Prevention, Pesticides and Toxic

Substances, Biological and Economic Analysis Division. May 14, 2012

. USEPA. 2012a. Ecological Incident Information System. Environmental Fate and Effects

Division. United States Environmental Protection Agency.

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September 11

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Available at http://www.regulations.gov/#!documentDetail;D=EPA

- HQ

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- 2012

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0543

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Ecological and Drinking Water Assessment . Environmental Fate and Effects Division.

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Environm ental Protection Agency. Available at

http://www.regulations.gov/#!docketDetail;D=EPA

- HQ

- OPP

- 2013

- 0676 (Accessed

April 11, 2014).

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Tomatoes (PP# 2E7993; IR

- 4) . DP Barcode no. 402283. January 2, 2013.

USEPA, Health Canada PMRA, & California Department of Pesticide Regulation. 2014.

Guidance for Assessing Pesticide Risks to Bees . June 23 , 2014. U.S. Environmental

Protection Agency. Health Canada Pest Management Regulatory Agency. California

Department of Pesticide Regulation. Available at http:/ /www2.epa.gov/pollinator

protection/pollinator

- risk

- assessment

- guidance (Accessed April 10, 2015).

### 66

8 .1 Submitted P roduct Chemistry and Environmental Fate Studies

161

- 1 Hydrolysis

40270 Raman, H.P. (1969) The Effect of pH, Time and Temperature on the Degradation of Ethrel. (Unpublished

study received Aug 27, 1971 under 2G1195; submitted by Union Carbide Agricultural Products Co., Ambler, Pa.;

CDL:095928

- C)

54003 Amchem Products, Incorporated (1972) (2

- Chloroethyl)phosphonic acid (Ethephon): Photodecomp osition

Study. (Unpublished study re

- ceived Dec 5, 1974 under 264

- 292; submitted by Union Carbide Ag

- ricultural

Products Co., Inc., Ambler, Pa.; CDL:230425

- E)

54004 Biddle, E.; Russell, K.E. (1969?) The Decomposition of 2

- Chloro

- ethylphosphonic acid in Aqueous

Solution under Controlled Condi

- tions of pH. (Unpublished study received Dec 5, 1974 under 264

- 292; prepared

by Queen's Univ., Dept. of Chemistry, Canada, sub

- mitted by Union Carbide Agricultural Products Co., Inc.,

Ambler, Pa.; CDL:230425

- G)

5 4007 Harrison, S. (1973) Letter sent to R.J. Otten dated Jan 26, 1973: Photodecomposition of (2

- Chloroethyl)phosphonic acid in dilute aqueous solution. (Unpublished study received Dec 5, 1974 under 264

- 292;

submitted by Union Carbide Agricultural Product s Co., Inc., Ambler, Pa.; CDL:230425

- K)

122420 Harrison, S. (1973) Letter sent to R. Otten dated Jan 26, 1973: Photodecomposition of (2

- chloroethyl)

phosphonic acid in dilute aqueous solution. (Unpublished study received 1973 under 2F1275; submitted by Un ion

Carbide Agricultural Products Co., Inc., Research Triangle Park, NC; CDL:095926

- B)

123944 Harrison, S. (1973) Letter sent to R. Otten dated Jan 26, 1973: Photodecomposition of (2

- chloroethyl)

phosphonic acid in dilute aqueous solution. (Unpublished st udy received 1973 under 3F1325; submitted by Union

Carbide Agricultural Products Co., Inc., Research Triangle Park, NC; CDL:093556

- C)

124862 Chib, J.; Heintzelman, R. (1983) Ethephon ... Photolytic Degrada

- tion Study: File No. 29241. (Unpublished

study re ceived Jan 18, 1983 under 264

- 257; submitted by Union Carbide Agricultural Products Co., Inc., Research

Triangle Park, NC; CDL:249295

- B)

136289 Biddle, E.; Russell, K. (1969) The Decomposition of 2

- chloroethyl

- phosphonic Acid in Aqueous Solution

under Con trolled Conditions of pH. (Unpublished study received Oct 3, 1972 under 3F1321; prepared by Queen's

Univ., Dept. of Chemistry, Ontario, sub

- mitted by Troy Janitorial Supply Co., Inc., Troy, MI; CDL: 092129

- I)

41545701 Das, Y. (1990) Hydrolysis of ?Ethyl( U)

- ?carbon 14|Ethephon in Aqueous Solutions Buffered at pH 5, 7

and 9: Lab Project Number: 89150. Unpublished study prepared by Innovative Scientific Services, Inc. 113 p.

161

- 2 Photodegradation

- water

41545601 Das, Y. (1990) Photodegradation of ?Ethyl(U)

- ?carbon 14||Ethephon in Aqueous Solution Buffered at pH

5 under Sunlight: Lab Project Number: 89151. Unpublished study prepared by Innovative Scien

- tific Services, Inc.

95 p.

### 67

161

- 3 Photodegradation

- soil

124861 Chib, J.; Heintzelman, R. (1981) Ethephon . .. Hydrolytic Degrada

- tion Study: File No. 29242.

(Unpublished study received Jan 18, 1983 under 264

- 257; submitted by Union Carbide Agricultural Products Co.,

Inc., Research Triangle Park, NC; CDL:249295

- A)

157624 Smith, B.; Huhtanen, K. (1986) Ethrel: P hotolysis of Ethephon (2

- Chloroethyl Phosphonic Acid) on a Soil

Surface: Project No. 866R10: File No. 34393. Unpublished study prepared by Union Carbide Agricultural Products

Co., Inc. 26 p.

41681401 Das, Y. (1990) Photodegradation of [Ethyl(U)

- (carbon 1 4)]| Ethephon on Soil under Artificial Sunlight:

Lab Project Number: 90032. Unpublished study prepared by Innovative Scientific, Inc. 106 p.

162

- 1 Aerobic soil metabolism

124863 Chib, J.; Heintzelman, R. (1983) Ethephon ... Aerobic Soil Metabo

- lism Study on Sand: File No. 31181.

(Unpublished study re

- ceived Jan 18, 1983 under 264

- 257; submitted by Union Carbide Agricultural Products Co.,

Inc., Research Triangle Park, NC; CDL:249295

- C)

41757701 Das, Y. (1991) Metabolism of [Ethyl(U)

- [carbon 14]Ethephon U nder Aerobic Soil Conditions: Lab

Project Number: EC

- 90

- 111: 90031. Unpublished study prepared by Innovative Scientific Services, Inc. 82 p.

162

- 3 Anaerobic aquatic metab.

157158 Huhtanen, K. (1986) Anaerobic Aquatic Metabolism Study [Using Ethrel]: Projec t No.

866R10. Unpublished study prepared by Union Carbide Agricultural Products Co., Inc. 13 p.

41757702 Das, Y. (1991) Metabolism of [Ethyl(U)

- [carbon 14]Ethephon Under Anaerobic Aquatic Soil Conditions:

Lab Project No: EC

- 90

- 112. Unpublished study prepar ed by Innovative Scientific Services, Inc. 92 p.

163

- 1 Leach/adsorp/desorption

27015 McManus, J. (1972) Soil Mobility Study of A

- 820. (Unpublished study received Sep 26, 1973 under 264

- 265; prepared by Amchem Products, Inc., submitted by Union Carbide Agri cultural Products Co., Ambler, Pa.;

CDL:120461

- F)

30177 Amchem Products, Incorporated (1976) Mobility of 2

- (3

- Chlorophen

- oxy)

- propionamide and 2

- (3

- Chlorophenoxy)

- propionic acid on Two Hawaiian Soils. (Unpublished study received Dec 10, 1979 under 264

- 338 ;

submitted by Union Carbide Agricultural Products Co., Ambler, Pa.; CDL:099174

- C)

33327 Union Carbide Agricultural Products Company (1972) Soil Mobility Study of A

- 820. (Unpublished study

received Dec 19, 1974 under 2G1285; CDL:093814

- J)

33334 McManus, J. (1972) Soil Mobility Study of A

- 820: Amchem Analytical Report. (Appendix; unpublished

study received Dec 19, 1974 under 2G1285; submitted by Union Carbide Agricultural Products Co., Ambler, Pa.;

CDL:093814

- U)

42974 Union Carbide Agricultural Products Comp any (1969) Effect of 2

- Chloroethylphosphonic acid on

Witchweed and Crops. (Unpub

- lished study received Dec 23, 1969 under 264

- 257; CDL:100700

- A)

54002 Amchem Products, Incorporated (1972) Studies of the Behavior of (2

- Chloroethyl) phosphonic acid

(Etheph on) in Soils. (Unpublished study received Dec 5, 1974 under 264

- 292; submitted by Union Carbide

Agricultural Products Co., Inc., Ambler, Pa.; CDL: 230425

- D)

### 68

71012 Chib, J.S.; North, S.P.; Harrison, S.L. (1980) Ethephon ?(2

- Chloro

- ethyl)phosphonic Acid| L eaching

Studies: Project No. 10221/580B. (Unpublished study received Feb 23, 1981 under 264

- 257; submit

- ted by Union

Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:244607

- A)

122405 U.S. Agricultural Research Service (1969) Evaluation of Experi

- mental Chemical for Activity on

Witchweed: ?Ethrel|. (Unpub

- lished study received Dec 23, 1969 under 264

- 257; submitted by Union Carbide

Agricultural Products Co., Inc., Research Triangle Park, NC; CDL:002225

- B)

125332 Heintzelman, R. (1983) Letter sent to W. Davis dated Jan 27, 1983: Ethephon leaching study. (Unpublished

study received Feb 1, 1983 under 264

- 376; submitted by Union Carbide Agricultural Products Co., Inc., Research

Triangle Park, NC; CDL:249424

- A)

129395 Union Carbide Agricultural Product s Co., Inc. (1972) Studies of the Behavior of (2

- Chloroethyl)phosphonicacid (Ethephon) in Soils. (Unpublished study received Jun 27, 1983 under 264

- 257; CDL:

250644

- K)

41263801 Dykes, J. (1989) Soil Adsorption/Desorption with ?Carbon 14|

- Ethe

- phon: Rept . No.

37275. Unpublished study prepared by Analytical Bio

- Chemistry Laboratories, Inc. 32 p.

42126001 Das, Y. (1991) Soil Adsorption and Desorption of ?carbon 14| Ethephon: Lab Project Number: ISSI

91020: EC

- 91

- 166. Unpub

- lished study prepared by Innovat ive Scientific Services, Inc. 182 p .

43991301 Miller, N.; Liu, A. (1996) 2

- Hydroxyethylphosphonic Acid (Ethephon Metabolite):

Adsorption/Desorption Study: Lab Project Number: EC

- 95

- 314: F95332

- 129: 1095 RP SOIL. Unpublished study

prepared by Rhone

- Poulen c Ag Co. 232 p.

44526801 Mislankar, S.; Estes, T. (1994) Adsorption/Desorption of (carbon 14)

- RPA 090946: Amended Final

Report: Lab Project Number: EC

- 94

- 259. Unpublished study prepared by Rhone

- Poulenc Ag Co. 98 p.

164

- 1 Terrestrial field dissipation

4 2974 Union Carbide Agricultural Products Company (1969) Effect of 2

- Chloroethylphosphonic acid on

Witchweed and Crops. (Unpub

- lished study received Dec 23, 1969 under 264

- 257; CDL:100700

- A)

54000 Fritz, C.D. (1971) Letter sent to Anson R. Cooke dated Mar 19, 1971: Ethrel rate of disappearance in soil.

(Unpublished study received Dec 5, 1974 under 264

- 292; submitted by Union Carbide Agricultural Products Co.,

Inc., Ambler, Pa.; CDL:230425

- B)

54001 Cantliffe, D.J.; Robinson, R.W. (1971) Response of cucumber to soil application of (2

- Chloroethyl)phosphonic acid. Horticultural Science 6(4):336

- 337. (Also~In~unpublished submission received Dec

5, 1974 under 264

- 292; submitted by Union Carbide Agricul

- tural Products Co., Inc., Ambler, Pa.; CDL:230425

- C)

116123 Amchem Products, Inc. (1970) Residue and Metabolism: Ethephon in Pineapples. (Compilation;

unpublished study received Jul 30, 1970 under 1F1016; CDL:091065

- A)

122405 U.S. Agricultural Research Service (1969) Evaluation of Experi

- mental Chemical for Activi ty on

Witchweed: ?Ethrel|. (Unpub

- lished study received Dec 23, 1969 under 264

- 257; submitted by Union Carbide

Agricultural Products Co., Inc., Research Triangle Park, NC; CDL:002225

- B)

125588 Union Carbide Agricultural Products Co., Inc. (1971) ?Ethrel Resi

- dues in Various Subjects|.

(Compilation; unpublished study re

- ceived Sep 1, 1971 under 1F1016; CDL:093325

- A)

### 69

42011501 Norris, F. (1991) A Terrestrial Field Soil Dissipation Study with Ethephon: Lab Project Number: EC

- 89

-

070: R092

- 079: R094

- 052. Unp ublished study prepared by Rhone

- Poulenc Ag Co., A & L East

- ern Agriculteral

Labs and A & L Western Agriculteral L abs. 250 p.

49305601 Chen, C. (2014) Independent Laboratory Validation of Bayer Method ET 001 S13;01: An Analytical

Method for the Determin ation of Residues of Ethephon and its Metabolite 2

- HEPA in Soil and Sediment Using

LC/MS/MS

- Final Report. Project Number: 13/CPS/029, RAETL041. Unpublished study prepared by Critical Path

Services, LLC (CPS). 107p.

49305603 Sears, K. (2014) Independen t Laboratory Validation of "An Analytical Method for the Determination of

Residues of Ethephon and its Metabolite 2

- HEPA in Water Using LC/MS/MS

- Final Report. Project Number:

RAETL042 80907. Unpublished study prepared by Pyxant Labs, Inc. 88p.

165

- 4 Bio accumulation in fish

136290 Sleight, B. (1972) Exposure of Fish to 14C

- labeled Ethephon: Accumulation, Distribution and Elimination

of Residues. (Unpub

- lished study received Oct 3, 1972 under 3F1321; prepared by Bionomics, Inc., submitted by

Troy Janitor ial Supply Co., Inc., Troy, MI; CDL:092129

- J)

164666 Kuo, W. (1981) [Carbon 14]

- Ethrel: Channel Catfish, Ictalurus punctatus (Rafinesque): Bioconcentration

Study: UCCES Project No. 11507

- 80. Unpublished study prepared by Union Carbide Corp. Environmental Services.

195 p.

### 70

8 .2. Submitted Ecotoxicity Studies

Avian Single Dose Oral Toxicity

MRID Citation Reference

26040 Beavers, J.B.; Fink, R.; Brown, R. (1979) Final Report: Acute Oral LD50

-- Mallard Duck: Project No. 113

- 146.

(Unpublished study re

- ceived Dec 19, 1979 under 264

- 267; prepared by Wildlife Interna

- tional, Ltd. in cooperation with

Washington College, submitted by Union Carbide Agricultural Products Co., Ambler, Pa.; CDL: 099158

- A)

26041 Beavers, J.B.; Fink, R.; Brown, R. (1979) Final R eport: Acute Oral LD50

-- Bobwhite Quail: Project No. 113

- 145.

(Unpublished study received Dec 19, 1979 under 264

- 267; prepared by Wildlife Inter

- national, Ltd. in cooperation with

Washington College, submitted by Union Carbide Agricultural Products Co., Am bler, Pa.; CDL: 099158

- B)

27493 Beavers, J.B.; Fink, R.; Brown, R. (1978) Final Report: Acute Oral LD50

-- Bobwhite Quail: Project No. 164

- 104.

(Unpublished study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Wildlife In

- ternational, Ltd. in cooperatio n with

Washington College, sub

- mitted by GAF Corp., Chemical Div., New York, N.Y.; CDL: 099355

- A)

27497 Hinkle, S.; Twigg, C.J. (1980) Final Report: Acute Oral LD50 Study in Bobwhite Quail: Project No. 257

- 111.

(Unpublished study received Apr 3, 1980 und er 1529

- EX

- 2; prepared by Hazleton Laboratories America, Inc., submitted by

GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- F)

27502 Moore, S.C.; Reno, F.E. (1979) Final Report: Acute Oral LD50 in Bobwhite Quail: Project No. 257

- 104. Rev.

(Unpublishe d study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Hazleton Labo

- ratories America, Inc., submitted by

GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- L)

54012 Gabriel, K.L. (1969) Acute Oral Toxicity

-- Bob White Quail. (Unpub

- lished study rec eived Dec 5, 1974 under 264

- 292; prepared by Biosearch, Inc., submitted by Union Carbide Agricultural Prod

- ucts Co., Inc., Ambler, Pa.; CDL:230425

- Q)

57812 Gabriel, K.L. (1969) Acute Oral Toxicity

-- Bob White Quail. (Unpub

- lished study received Sep 4, 19 75 under 264

- 290;

prepared by Biosearch, Inc., submitted by Union Carbide Agricultural Prod

- ucts Co., Inc., Ambler, Pa.; CDL:225086

- C)

69674 Gabriel, K.L. (1969) Acute Oral Toxicity

-- Bob White Quail. (Unpub

- lished study received Feb 27, 1970 under

1F101 6; prepared by Biosearch, Inc., submitted by Amchem Products,

Inc., Ambler, Pa.; CDL:091064

- J)

Avian Dietary Toxicity

MRID Citation Reference

27494 Hinkle, S.; Cameron, J.T. (1979) Final Report: Avian Dietary Toxic

- ity (LC50) Study in Bobwhite Qua il: Project No.

257

- 108. (Un

- published study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Hazleton Laboratories America, Inc.,

submitted by GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- B)

27498 Hinkle, S.; Cameron, J.T. (1979) Final Report: Avian Dietary Toxic

- ity (LC50) Study in Bobwhite Quail: Project No.

257

- 110. (Un

- published study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Hazleton Laboratories America, Inc.,

submitted by GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- G)

27503 Moore, S.C.; Reno, F.E. (1979) Final Report: Subacute Dietary LC50 in Bobwhite Quail: Project No. 257

- 106. Rev.

(Unpublished study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Hazleton Laboratories America, Inc., submitted by

GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- M)

27504 Moore, S.C.; Reno, F.E. (1979) Final Report: Subacute Dietary LC50 in Mallard Ducks: Project No. 257

- 105. Rev.

(Unpublished study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Hazleton Labo

- ratories America, Inc., submitted by

### 71

GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- N)

56480 Hinkle, S.; Cameron, J.T. (1979) Final Report: Avian Dietary Toxic

- ity (LC50) Study in Mallard Ducks: Project No.

257

- 107. (Un

- published study received Apr 3, 1980 under 15 29

- EX

- 2; prepared by Hazleton Laboratories America, Inc.,

submitted by GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- C)

72983 Fink, R. (1972) Final Report: Eight

- Day Dietary LCI50^

-- Mallard Ducks: Project No. 141

-

246. (Unpublished study received D ec 5, 1974 under 264

- 292; prepared by Environmental Sciences Corp., submitted by Union

Carbide Agricultural Products Co., Inc., Am

- bler, Pa.; CDL:230425

- P)

73622 Fink, R. (1972) Final Report: Eight

- Day Dietary LCI50^

-- Mallard Ducks: Project No. 141

-

246. (Unpublished study received Sep 4, 1975 under 264

- 290; prepared by Environmental Sciences Corp., submitted by Union

Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:225086

- B)

85446 Fink, R.; Beavers, J.B.; Brown, R. (1977) Final Report: Eight

- da y Dietary LCI50^

-- Bobwhite Quail: Project No. 113

-

139. (Unpub

- lished study received Mar 2, 1979 under 264

- 267; prepared by Wildlife International, Ltd. and Washington

College, submitted by Union Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:0 97830

- F)

104086 Fink, R.; Reno, F. (1976) Final Report: Eight

- day Dietary LC50

-- Bobwhite Quail: ?

CPGR/2|: Project No. 257

- 203. (Unpublished study received Feb 9, 1976 under 1529

- 20; prepared by Truslow Farms, Inc. and

Hazleton Laboratories America, Inc.

, submitted by GAF Corp., Chemical Div., New York, NY; CDL:239732

- A)

107428 Fink, R.; Reno, F. (1974) Final Report: Eight

- day Dietary LC50

-- Mallard Ducks: ?CPGR|: Project No. 257

- 102.

(Unpublished study received Mar 15, 1974 under 1529

- 20; prepared by Tru slow Farms, Inc., and Environmental Sciences Corp.,

submitted by GAF Corp., Chemical Div., New York, NY; CDL:132053

- A)

122414 Fink, R. (1972) Eight

- day Dietary LC50

-- Mallard Ducks: Ethephon: Project No. 141

- 246. Final rept. (Unpublished

study received Dec 5, 1974 under 264

- 292; prepared by Hazleton Laboratories, Inc., submitted by Union Carbide Agricultural

Products Co., Inc., Research Triangle Park, NC; CDL:028299

- D)

123801 Fink, R.; Reno, F. (1974) Eight

- day Dietary LC50

-- Mallard Ducks: CPGR: Project No

. 257

- 102. Final rept. (Unpublished study received Mar 15, 1974 under unknown admin. no.; prepared by Hazleton Laboratories,

Inc., submitted by GAF Corp., Chemical Div., New York, NY; CDL:131715

- A)

40874301 Fletcher, D. (1988) 8

- Day Dietary LC50 Study wi th Base 250 in Bob

- white Quail: Project No. BLALA Study No.

86 QC 75. Unpublished study prepared by Bio

- Life Associates, Ltd. 73 p.

41080201 Fletcher, D. (1988) 8

- Day Dietary LC50 Study with Base 250 in Bob

- white Quail: Project No. BLAL Study No. 86

QC 75. Unpublished study prepared by Bio

- Life Associates, Ltd. 73 p.

Acute Toxicity to Freshwater Fish

MRID Citation Reference

122412 Sleight, B. (1971) The Acute Toxicity of Ethrel to Bluegill

... and

... Salmo gairdneri. (Unpublished study received Dec

5

, 1974 under 264

- 292; prepared by Bionomics, Inc., submitted by Union Carbide Agricultural Products Co., Inc., Research

Triangle Park, NC; CDL:028299

- B)

122443 Pitcher, F. (1974) (Cepha

-- Bluegill): Test No. 665. (Unpublished study received Mar 13, 1974 un der 1529

- 20; prepared

by Pesticides Regulation Div., Animal Biology Laboratory, submitted by U.S. Environmental Protection Agency, Beltsville,

MD; CDL: 128204

- A)

44389903 Dionne, E. (1997) Finish

-- Acute Toxicity to Channel Catfish (Ictalurus punctatus) U nder Flow

- Through Conditions:

Final Report: Lab Project Number: 97

- 2

- 6870: 10566.1096.6407.107: 100296/FIFRA/107/FIN. Unpublished study prepared by

Springborn Labs, Inc. 90 p. (Relates to L0000183)

Acute Toxicity to Freshwater Invertebrates

### 72

MRID Citation Reference

122448 Pitcher, F. (1974) (Cepha

-- Daphnia magna): Test No. 672. (Unpublished study received Mar 13, 1974 under 1529

- 20;

prepared by Pesticides Regulation Div., Animal Biology Laboratory, submitted by U.S. Environmental Protection Agency,

Belts ville, MD; CDL: 132055

- A)

Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

41296202 Dionne, E. (1989) Ethephon

-- Acute Toxicity to Eastern Oyster (Crassostrea virginica) under Flow

- through

Conditions: Final: SLI Report No. 89

- 10

- 3121 ; SLI Study 10566.1288.6123.504. Unpublished study prepared by Springborn

Laboratories, Inc., Environmental Sciences Div. 37 p.

Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

MRID Citation Reference

27495 Bentley, R.E. (1974) Acute Toxicity of CPGR Formulation and CPGR 100% to Bluegill (?

~Lepomis macrochirus~?) and Rainbow Trout (?~Salmo gairdneri~?). (Unpublished study received Apr 3, 1980 under 1529

- EX

2; prepared by Bionomics, EG&G Environmental Con

- sultants, submitted by GAF Corp., Che mical Div., New York, N.Y.;

CDL:099355

- D)

27496 Foote, K.C. (1978) Toxicity Test of GAF's Corporation: Teceth 75 ?8065

- 20|: Contract No.

L1362

- 05. (Unpublished study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Syracuse Research Corp., submitted by G AF

Corp., Chemical Div., New York, N.Y.; CDL:099355

- E)

27499 Foote, K.C. (1979) Toxicity Test of GAF Corporation's NMP with ?~Lepomis macrochirus~(Bluegill): Contract No.

L1393

- 05. (Un

- published study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Syr acuse Research Corp., submitted by

GAF Corp., Chemical Div., New York, N.Y.; CDL:099355

- I)

27501 Posner, S. (1969) The Effect of Methyl pyrrolidone on Fingerling Fish: Laboratory No. 90458. (Unpublished study

received Apr 3, 1980 under 1529

- EX

- 2; prepared by Food and Drug Research Labo

- ratories, Inc., submitted by GAF Corp.,

Chemical Div., New York, N.Y.; CDL:099355

- K)

27505 Buccafusco, R.J. (1978) Acute Toxicity of Sample 7767

- 141AF to Bluegill (?~Lepomis macrochirus~?) and Rainbow

Trout (?~Salmo ?~gair dneri~?): Report # BW

- 78

- 4

- 115. (Unpublished study re

- ceived Apr 3, 1980 under 1529

- EX

- 2; prepared

by Bionomics, EG&G, submitted by GAF Corp., Chemical Div., New York, N.Y.; CDL: 099355

- O)

27506 Foote, K.C. (1979) Toxicity Test of GAF Corporation's 7767

- 141: Contract No. L1393

- 05. (Unpublished study

received Apr 3, 1980 under 1529

- EX

- 2; prepared by Syracuse Research Corp., submitted by GAF Corp., Chemical Div., New

York, N.Y.; CDL:099355

- P)

54010 Sleight, B.H., III (1971) Bioassay Report: The Acute Toxi city of Ethrel to Bluegill (?

~Lepomis macrochirus~?) and Rainbow Trout (?~Salmo gairdneri~?). (Unpublished study received Dec 5, 1974 under 264

- 292;

prepared by Bionomics, Inc., submitted by Union Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL: 230425

- N)

42294501 Putt, A. (1992) Ethephon Technical

-- The Chronic Toxicity to Daphnia magna Under Flow

- through Conditions:

Final Report: Lab Project Number: 92

- 1

- 4074: 10566.0891.6210.130. Unpublished study prepared by Springborn Labs., Inc. 98

p.

81

- 1 Acute oral toxicity in rats

MRID Citation Reference

28615 Griffiths, J.T.; Babish, J.G. (1978) Approximate Acute Oral Toxic

- ity (LD50) in Rats: Laboratory No. 5659b.

(Unpublished study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Food and Drug R esearch Laboratories, Inc., submitted

by GAF Corp., Chemical Div., New York, N.Y.; CDL:099359

- D)

### 73

28620 Griffiths, J.T.; Babish, J.G. (1978) Approximate Acute Oral Toxic

- ity (LDI50^) in Rats: Laboratory No. 5659a.

(Unpublished study received Apr 3, 1980 u nder 1529

- EX

- 2; prepared by Food and Drug Research Laboratories, Inc., submitted

by GAF Corp., Chemical Div., New York, N.Y.; CDL:099359

- I)

29509 Griffiths, J.T.; Parent, R.A. (1979) The Approximate Acute Oral Toxicity (LDI50^) of GAF CPD 71921/L9 in Male

Sprague

- Dawley Rats: Laboratory No. 2

- 6153. (Unpublished study received Apr 3, 1980 under 1529

- EX

- 2; prepared by Food

and Drug Research Labora

- tories, Inc., submitted by GAF Corp., Chemical Div., New York, N.Y.; CDL:099356

- A)

55315 Holsing, G.C. (1968) Final Report: Acute Oral Administration

-- Rats: Project No. 141

- 169. (Unpublished study

received Mar 6, 1969 under 264

- 263; prepared by TRW, Inc., submitted by Union Carbide Agricultural Products Co., Inc.,

Ambler, Pa.; CDL: 002234

- D)

57166 Moldovan, M. (1974) Determination of the Acute Oral LDI50^: OE No. 4199

- 1670. (Unpublished study received Jul

16, 1974 under 1529

- 20; prepared by Food and Drug Research Laboratories, Inc., submitted by GAF Corp., Chemical Div., New

York, N.Y.; CDL: 119822

- A)

81317 Fie ld, W.E.; Carter, W. (1978) Oral LDI50^ In Rats: Study No. CDC

- AM

- 014

- 78. (Unpublished study received Mar

2, 1979 under 264

- 267; prepared by CDC Research, Inc., submitted by Union Carbide Agricultural Products Co., Inc., Ambler,

Pa.; CDL:097830

- A)

85754 Weatherholtz, W.M.; Twigg, C.J.; Wolfe, G.W. (1980) Acute Oral Toxicicity Study in Rabbits: Project No. 400

- 630.

Final rept. (Unpublished study received Oct 19, 1981 under 264

- 267; pre

- pared by Hazleton Laboratories America, Inc.,

submitted by Union Carb ide Agricultural Products Co., Inc., Ambler, Pa.; CDL:246064

- A)

89757 Bach, K.J. (1974) Acute Oral Toxicity in Rats: ?Amchem 73

- A191|. Final rept. (Unpublished study received Mar 18,

1974 under 264

- 290; prepared by Affiliated Medical Research, Inc., subm itted by Union Carbide Agricultural Products, Co.,

Inc., Ambler, Pa.; CDL:023033

- E)

116549 DeProspo, J. (1972) Effective Dose for Vomiting: ?Tech. Ethrel|: Contract No. 121

- 1498

-

52. Final rept. (Unpublished study re

- ceived Oct 8, 1972 under 2F1275; prep ared by Affiliated Medical Enterprises, Inc.,

submitted by Amchem Products, Inc., Ambler, PA; CDL:091812

- C)

116670 Myers, R.; Coleman, J.; Bellich, N.; et al. (1982) Ethephon AXF

- 1209: Acute Toxicity and Irritancy Study: Project

Report 45

- 172. (Unpublish ed study received Oct 15, 1982 under 264

- 380; sub

- mitted by Union Carbide Agricultural Products

Co., Inc., Re

- search Triangle Park, NC; CDL:248658

- A)

116931 Holsing, G. (1968) Acute Oral Administration

-- Rats: Amchem 68

- 250 (Ethrel) 39.5% Active Ingred ient by Weight:

Project No. 141

- 169. Final rept. (Unpublished study received Jul 29, 1970 under 1F1016; prepared by Hazleton Laboratories,

Inc., submitted by Amchem Products, Inc., Ambler, PA; CDL:092124

- B)

122446 Hazleton Laboratories, Inc. (1968) Acute Oral Administration

-- Rats: Amchem 68

- 250 (Ethrel) 39.5% Active Ingredient

by Weight: Project No. 141

- 169. Final rept. (Unpublished study received Sep 1, 1969 under 264

- 263; submitted by Union

Carbide Agricul

- tural Products Co., Inc., Research Triangle Par k, NC; CDL: 129923

- C)

128627 Myers, R.; Christopher, S.; Coleman, J.; et al. (1983) Cerone 4 Liquid Plant Growth Regulator

-- Peroral and

Percutaneous Toxicity Study: Project Report 46

- 37. (Unpublished study received May 11, 1983 under 264

- 257; submitted by

Union Carbide Agricultural Products Co., Inc., Research Triangle Park, NC; CDL:250387

- A)

41154501 Myers, R. (1989) Acute Peroral Toxicity Study: Ethephon Base 250: Project ID 47

- 49 (Revised). Unpublished study

prepared by Bushy Run Research Center. 11 p

.

43123904 Kuhn, J. (1993) Flordimex

- Konzentrat (sic) 65 (Ethephon 65%): Acute Oral Toxicity Study in Rats: Lab Project

Number: 0421

- 93. Unpublished study prepared by Stillmeadow, Inc 23 p.

43368423 Douds, D. (1993) An Acute Oral Toxicity Study in Rats with EXP 31039B: Final Report: Lab Project Number:

3147.185. Unpublished study prepared by Springborn Labs, Inc. 69 p.

43837102 Wnorowski, G. (1995) ETK

- 2201: Acute Oral Toxicity Test (in Rats): Lab Project Number: 3936. Unpublished

### 74

study prepared by Pr oduct Safety Labs. 22 p.

43849401 Kuhn, J. (1994) Ethephon 6#: Acute Oral Toxicity Study in Rats: Lab Project Number: 0610

- 93. Unpublished study

prepared by Stillmeadow, Inc. 23 p.

43920501 Varsho, B. (1996) Acute Oral Toxicity of Florel Plant Growth R egulator in Albino Rats: Final Report: Lab Project

Number: WIL

- 21068. Unpublished study prepared by WIL Research Labs, Inc. 25 p.

43920502 Varsho, B. (1996) Acute Oral Toxicity Study of Ethrel Plant Regulator in Albino Rats: Final Report: Lab Project

Num ber: WIL

- 21069. Unpublished study prepared by WIL Research Labs, Inc. 51 p.

44652501 Douds, G. (1998) An Acute Oral Toxicity Study in Rats with EXP 31648A: Final Report: Lab Project Number:

3147.258. Unpublished study prepared by Springborn Laboratories, Inc. 34 p.

45568104 Rodabaugh, D. (2001) An Acute Oral Toxicity Study in Rats with Finish Extra: Final Report: Lab Project Number:

3522.41. Unpublished study prepared by Springborn Laboratories, Inc. 26 p. {OPPTS 870.1100}

2

- generation repro.

- rat

MRID Citation Reference

36508 Weatherholtz, W.M.; Ferrell, J.F. (1972) Final Report: Three

- Gener

- ation Reproduction Study

-- Rats: Project No. 141

-

214. (Unpub

- lished study received on unknown date under 4F1490; prepared by Hazleton Laboratories, Inc., submitte d by

Union Carbide Agricul

- tural Products Co., Ambler, Pa.; CDL:093946

- B)

80405 Weatherholtz, W.M. (1972) Final Report: Three

- generation Reproduc

- tion Study

-- Rats: Project No. 141

- 214.

(Unpublished study re

- ceived Oct 6, 1972 under 2F1275; prepared

by Environmental Sci

- ences Corp., submitted by Union Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:091810

- A)

80985 Weatherholtz, W.M. (1972) Final Report: Three

- generation Reproduc

- tion Study

-- Rats: Project No. 141

- 214.

(Unpublished study re

- ceived Dec 5, 1974 under 264

- 292; prepared by Environmental Sciences Corp., submitted by Union

Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:028298

- B)

81076 Weatherholtz, W.M. (1972) Final Report: Three

- generation Reproduc

- tion Study

-- Rats: P roject No. 141

- 214.

(Unpublished study re

- ceived Dec 5, 1974 under 264

- 292; prepared by Environmental Sci

- ences Corp., submitted by Union

Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:050583

- B)

81781 Union Carbide Agricultural Products Compan y, Incorporated (1970) Three

- generation Reproduction Study

-- Rats.

(Unpublished study received May 7, 1971 under 1G1172; CDL:090971

- B)

83627 Weatherholtz, W.M. (1972) Final Report: Three

- generation Reproduc

- tion Study

-- Rats: Project No. 141

- 214.

(Unpublish ed study re

- ceived Jun 1, 1974 under 5F1524; prepared by Environmental Sciences Corp., submitted by Union

Carbide Agricultural Products Co., Inc., Ambler, Pa.; CDL:094482

- B)

41508701 Neeper

- Bradley, T.; Tyl, R. (1990) Two

- generation Reproduction Study in CD Albino Rats exposed to Ethephon by

Dietary Inclu

- sion: Lab Project I.D.: 51

- 539. Unpublished study prepared by Union Carbide Bushy Run Research Center. 760 p.

Seed Germination/Seedline Emergence and Vegetable Vigor

MRID Citation Reference

41403 305 Hoberg, J. (1990) Ethephon

-- Determination of Effects on Seedling Germination, Shoot Emergence and Seedling

Vigor of Ten Plant Species: Lab Project Number: 90

- 2

- 3220: 10566

- 1288

- 6124

- 610. Unpublished study prepared by Springborn

Laboratories, Inc. 311 p.

44518602 Teixeira, D. (1998) EXP

- 31039C

-- Determination of Effects on Seedling Emergence of Two Plant Species and

Vegetative Vigor of Ten Plant Species: Lab Project Number: 97

- 12

- 7199: 10566.0797.6431.610. Unpublished study prepared

by Springborn Labo ratories, Inc. 263 p.

Aquatic plant growth

MRID Citation Reference

### 75

41403301 Giddings, J. (1990) Ethephon

-- Toxicity to the Marine Diatom Skele

- tonema costatum: Lab Project Number: 90

- 1

-

3207: 10566

- 0389

- 6131

- 450. Unpublished study prepared by Spri ngborn Laboratories, Inc. 36 p.

41403302 Giddings, J. (1990) Ethephon

-- Toxicity to the Freshwater Diatom Navicula pelliculosa: Lab Project Number: 90

- 2

-

3234: 10566

- 0389

- 6131

- 440. Unpublished study prepared by Springborn Laboratories Inc. 36 p.

41403303 Giddings, J. (1990) Ethephon

-- Toxicity to the Freshwater Bluegreen Alga Anabaena flos

- aquae: Lab Project

Number: 90

- 1

- 3206: 10566

- 0389

- 6131

- 420. Unpublished study prepared by Springborn Labora

- tories, Inc. 35 p.

41403304 Giddings, J. (1990) Ethephon

-- T oxicity to the Freshwater Green Alga Selenastrum capricornutum: Lab Project

Number: 90

- 1

- 3197: 10566

- 0389

- 6131

- 430. Unpublished study prepared by Springborn Labora

- tories, Inc. 36 p.

41509001 Giddings, J. (1990) Ethephon

-- Toxicity to the Freshwater Plan t Lemna gibba G3: Final Report: SLI Report No.: 90

-

04

- 3302; SLI Study No.: 10566.0389.6131.410. Unpublished study prepared by Springborn Laboratories, Inc., Environmental

Sciences Div. 42 p.

Seed germination/seedling emergence and vegetative vigor

MRID C itation Reference

43868323 Hoberg, J. (1995) EXP

- 31039B

-- Determination of Effects on Seedling Emergence and Vegetative Vigor of Ten

Plants Species: Lab Project Number: 95

- 5

- 5867: 10566.0495.6364.610. Unpublished study prepared by Springborn Labs, In c.

343 p.

44518602 Teixeira, D. (1998) EXP

- 31039C

-- Determination of Effects on Seedling Emergence of Two Plant Species and

Vegetative Vigor of Ten Plant Species: Lab Project Number: 97

- 12

- 7199: 10566.0797.6431.610. Unpublished study prepared

by Springbo rn Laboratories, Inc. 263 p.

Aquatic plant growth

MRID Citation Reference

41509001 Giddings, J. (1990) Ethephon

-- Toxicity to the Freshwater Plant Lemna gibba G3: Final Report: SLI Report No.: 90

-

04

- 3302; SLI Study No.: 10566.0389.6131.410. Unpubli shed study prepared by Springborn Laboratories, Inc., Environmental

Sciences Div. 42 p.

850.2100 Avian acute oral toxicity test

MRID Citation Reference

49160601 Christ, M. ; Shepherd, J. (2013) Toxicity of Ethephon Technical During an Acute Oral LD 50 with the Canary

(Serinus canaria). Project Number: 07SRLS13C3. Unpublished study prepared by SynTech Research Laboratory Services, LLC.

51p.

850.2300 Avian reproduction test

MRID Citation Reference

### 76

48202005 Mitchell, L.; Martin, K.; Beavers, J. ; et al. (2001) Ethephon: A Reproduction Study with the Japanese

Quail: Final Report. Project Number: 171/159, C012884. Unpublished study prepared by Wildlife International, Ltd.

158 p.

49305605 Christ, M.; Shepherd, J.; Moore, S. (2014) Toxicity of Ethep hon (Base 250) on the Reproduction of the

Mallard Duck (Anas platyrhynchos). Project Number: 07SRLS13C4. Unpublished study prepared by SynTech

Research Laboratory Services, LLC. 73p.

49325701 Stafford, J. (2014) Ethephon: Reproductive Toxicity Test with t he Northern Bobwhite (Colinus

virginianus): Final Report. Project Number: 13798/4138, XY4711. Unpublished study prepared by Smithers Viscient.

439p.

850.3020 Honey bee acute contact toxicity

MRID Citation Reference

48202006 Schmitzer, S.; Sterk, N

. (1999) Laboratory Testing for Toxicity (Acute Contact and Oral LD50) of

Ethephon on Honey Bees (Apis mellifera L.) (Hymenoptera, Apidae): Final Report. Project Number: R006341,

6291036. Unpublished study prepared by Institut fuer Biologische Analytik und Consulting IBACON. 28 p.

850.4225 Seedling emergence, Tier II

MRID Citation Reference

49037901 Kohler, P. (2012) Ethephon 71.3: Effects on the Seedling Emergence and Growth of Three Species of

Non

- Target Terrestrial Plants (Tier 2). Project Number : VV12/038, EBETL017, M/443312/01/1. Unpublished study

prepared by Bayer CropScience GmbH. 116p.

850.4250 Vegetative vigor, Tier II

MRID Citation Reference

48976901 Kohler, P. (2012) Ethephon 71.3: Effects on the Vegetative Vigour of Six Species o f Non

- Target

Terrestrial Plants (Tier 2): Final Report. Project Number: M/443312/01/1/OCR, VV12/038, EBETL017. Unpublished

study prepared by Bayer CropScience GmbH. 140p.

49037902 Kohler, P. (2012) Ethephon 71.3: Effects on the Vegetative Vigour of Six C rop Species of Non

- Target

Terrestrial Plants (Tier 2). Project Number: VV12/038, EBETL017, M/443312/01/1. Unpublished study prepared by

Bayer CropScience GmbH. 140p.

### 77

Appendix A . Selected SWCC Output Files



# Summary of Wa ter Modeling of Ethephon and the USEPA

Standard Pond

Turf

Table 1. Estimated Environmental Concentrations (ppb) for Ethephon.

Peak (1

- in

- 10 yr) 17.7

4

- day Avg (1

- in

- 10 yr) 9.00

21

- day Avg (1

- in

- 10 yr) 3.97

60

- day Avg (1

- in

- 10 yr) 2.89

365

- day Avg (1

- in

- 10 yr) 0.489

Entire Simulation Mean 0.434

Table 2. Summary of Model Inputs for Ethephon.

Scenario FLturfSTD

Cropped Area Fraction 1

K d 

### (ml/g) 30

Water Half

- Life (days) @ 25 °C 2.6

Benthic Half

- Life (days) @ 25 °C 16

Photolysis Half

- Life (days) @ 40

°Lat 139

Hydrolysis Half

- Life (days) 2.4

Soil Half

- Life (days) @ 22 °C 13

Foliar Half

- Life (days) 35

Molecular Wt 144.5

Vapor Pressure (torr) 1E

- 7

Solubility (mg/l) 1.2E6

### 78

Table 3. Application Schedule for Ethephon.

Date (Mon/Day) Type Amount (kg/ha) Eff. Drift

03/1 Ground 4.48 0.99 0.062

03/15 Ground 4.48 0.99 0.062

03/29 Ground 4.48 0.99 0.062

04/12 Ground 4.48 0.99 0.062

04/26 Ground 4.48 0.99 0.062

### 79

Appendix B

. Toxicity Categories and Levels of Co ncern

Table B1. Categories of Toxicity for Aquatic Organisms

L C 50 ( p pm) Toxici t y C a t e go r y

< 0

. 1 Very hi g h ly t o xic

> 0

. 1

- 1 Hi g h ly toxic

> 1

- 10 M od e rately t o xic

> 1 0

- 1 0 0 Slightly toxic

> 1 00 Practically n on toxic



### Table B2. C ategories of Toxicity for Te r res t rial Organisms

Oral d o se LD 5 0 ( m g/k g

- b w ) Toxici t y C a t e go r y

< 10 Very h ig h ly to x ic

10

- 5 0 Hi g h ly toxic

5 1

- 500 M od e rately t o xic

5 0 1

- 2 0 0 0 Slightly toxic

> 2 0 00 Practically n ont ox ic

Die t ary L C 50 (ppm) Toxici t y C a t e go r y

< 50 Very h ig h ly to x ic

5 0

- 500 H i g h ly t ox i c

5 0 1

- 1 0 0 0 M od e rately t o x ic

1 00 1

- 5 00 0 Slightly toxic

> 5 0 00 Practically n ont ox ic



### Table B3. Categories of Toxicity for Honey Bee

Bee A c ute Contact L D 50 (μg / bee) Toxici t y C a t e go r y

<2 Hig h ly t ox ic

2

– 1 0

. 9 9 M od e rately t o x ic

> 11 Practically nontoxic



### Table B4. Levels of Concern for Te rr estrial and Aquatic Organisms

T a xa Acu t e L O C Ch r o nic L O C

Avi a n 1 (t e rres t

rial p h ase a m

phibia n s) 0

. 1 1

M a m m a lia n 2 0

. 1 1

Terres t rial pla n ts 3 1

Aq u atic A n i m a ls 4 (aq u atic phase

a m phibia n s) 0

. 05 1

Insects 5 0

. 05 1

Used in RQ ca lc ulations:

1 L D 50 and es t i m a ted NOEL

2 L D 50 and NOEC

3 EC25

4 LC / EC 50 and estimated and r e p roducti v e NOEC

5 L D 50 p e r EF E D’s CRLF Steer i ng Co mm ittee

### 80

Appendix C . Example T

- REX (v. 1.5 .2 ) Inpu t and Output for Ethephon

Table D .1. T

- REX Model Inputs: Chemical Application Scenarios and Body Mass for Assessed

Species.

Table D .2. Avian and Mammalian Toxicity Endpoints for RQ Calculation.

### 81

### 82

Appendix D

. STIR Results

### 83

Appendix E . S creenin g Imbibition Program (SIP) Version 1.0 Inputs and Results

### 84

Appendix F

. A cce p t ed E C O T O X D a t a Ta b l e (2008 to 2015 Refresh Report)

Th e c od e li st f

o r E C O T O X can b e f

oun d a t : htt p :// c f

p u b

. e p a .gov/ ec otox/

b l ac k b ox/h e l p / c od e li s t. p df

Genus Species Common

Name Effect

Group Effect Meas Endpt1 Endpt2 Dur

Preferred

Mean Dur Unit

Preferred Conc Units

Preferred %

Purity Ref #

Rhododendron sp. Azaleas GRO GRO GGRO NOAEL 56 d % 100 81589

Rhodo dendron sp. Azaleas GRO MPH LGTH NOAEL 21 d % 100 81589

Rhododendron sp. Azaleas GRO MPH LGTH NOAEL 21 d % 100 81589

Rhododendron sp. Azaleas GRO GRO GGRO NOAEL 56 d % 100 81589

Rhododendron sp. Azaleas GRO DVP GDVP NOAEL 42 d % 100 81589

Rhodo dendron sp. Azaleas GRO DVP GDVP NOAEL 42 d % 100 81589

Abutilon theophrasti Butter print GRO GRO LGTH LOAEL 4 d ppm >=95 106960

Abutilon theophrasti Butter print REP REP VIAB LOAEL 4 d ppm >=95 106960

Fusarium oxysporum Fungi POP POP ABND NOAEL 4 d ppm >=95 106960

Abutilon theophrasti Butter print GRO DVP EMRG NOAEL 28 d ppm >=95 106960

Abutilon theophrasti Butter print REP REP VIAB NOAEL 28 d ppm >=95 106960

Abutilon theophrasti Butter print GRO GRO WGHT LOAEL 28 d ppm >=95 106960

NR Fungi Fungi Kingdom POP POP ABND NOAEL 28 d ppm >=95 106960

Fusarium oxysporum Fungi POP POP ABND NOAEL 28 d ppm >=95 106960

Oryza sativa Rice BCM HRM ABSA NOEC fs M 100 98600

Oryza sativa Rice BCM BCM ETHL LOEC fs M 100 98600

Oryza sativa Rice CEL CEL CDRT NOEC fs M 100 98600

Oryza sativa Rice GRO DVP DVLP NOEC fs M 100 98600

Oryza sativa Rice GRO GRO WGHT NOEC ma M 100 98600

Prays oleae Olive Moth POP POP INDX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP INDX L OAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP PRPE NOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP INDX N OAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP PRPE NOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 1095 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 1095 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 1095 d % 100 116440

Prays oleae Olive Moth POP POP PRPE NOAEL 1095 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 365 d % 100 116440

### 85

Prays oleae Olive Moth POP POP IN DX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP PRPE LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP IN DX NOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP PRPE NOAEL 730 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP IN DX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP INDX LOAEL 365 d % 100 116440

Prays oleae Olive Moth POP POP PRPE NOAEL 365 d % 100 116440

Phloeotribus scarabaeoides Olive Bark

Beetle POP POP ABND NOAEL 19 d % 48 116051

Phloeotribus scarabaeoides Olive Bark

Beetle POP POP ABND NOAEL 26 d % 48 116051

Phloeotribus scarabaeoides Olive Bark

Beetle POP POP ABND NOAEL 33 d % 48 116051

Phloeotribus scarabaeoides Olive Bark

Beetle POP POP ABND NOAEL 40 d % 48 116051

Triglochin mariti ma Arrowgrass REP REP GERM LOAEL 20 d mM 100 115844

Neoseiulus fallacis Predatory mite MOR MOR MORT LC50 2 d gal/100 gal 100 71217

Tetranychus urticae Two

- spotted

spider mite MOR MOR MORT LC50 2 d gal/100 gal 100 71217

Anabaena flosaquae Blue

- gree n

algae POP POP BMAS EC50 4 d mg/L 85 95681

Microcystis aeruginosa Blue

- green

algae POP POP BMAS EC50 4 d mg/L 85 95681

Microcystis flosaquae Blue

- green

algae POP POP BMAS EC50 4 d mg/L 85 95681

Chlorella pyrenoidosa Green algae POP POP BMAS EC50 4 d mg/L 85 95681

Anthonomus grandis Boll Weevil POP POP ABND LOAEL 3 d AI kg/ha 100 115843

Anthonomus grandis Boll Weevil POP POP ABND LOAEL 10 d AI kg/ha 100 115843

Anthonomus grandis Boll Weevil POP POP ABND NOAEL 44 d AI kg/ha 100 115843

An thonomus grandis Boll Weevil POP POP ABND NOAEL 36 d AI kg/ha 100 115843

Anthonomus grandis Boll Weevil POP POP ABND NOAEL 30 d AI kg/ha 100 115843

Phymatotrichum omnivora Fungus POP POP DMTR LOAEL d ppm 100 115652

Oryza sativa Rice BCM BCM ETHL LOAEL 2 d M 100 108051

Oryza sativa Rice BCM BCM ETHL LOAEL 2 d M 100 108051

Oryza sativa Rice GRO GRO WGHT LOAEL ma M 100 108051

### 86

Oryza sativa Rice REP REP STRL LOAEL ma M 100 108051

Oryza sativa Rice GRO GRO WGHT LOAEL ma M 100 108051

Oryza sativa Rice REP REP STRL LOAEL ma M 100 108051

Septoria apiicola Fungus REP REP GERM NOAEL LOAEL 3.666666667 d ppm 100 116149

Prays oleae Olive Moth POP POP ABND LOAEL d AI g/ha 100 116150

Olea europaea Olive POP POP BMAS NOAEL hv lb /acre 100 116150

Oryza sativa Rice BCM BCM MLDH LOAEL 9 d mM 100 116151

Oryza sativa Rice BCM BCM MLDH LOAEL 9 d mM 100 116151

Oryza sativa Rice BCM ENZ GENZ LOAEL 9 d mM 100 116151

Oryza sativa Rice BCM ENZ GENZ LOAEL 9 d mM 100 116151

Oryza sativa Rice GRO MPH WGHT LOAEL hv mM 100 116151

Oryza sativa Rice GRO MPH WGHT LOAEL hv mM 100 116151

Aphis gossypii Cotton aphid POP POP ABND NOAEL 4 d AI lb/acre 100 116381

Aphis gossypii Cotton aphid POP POP ABND NOAEL 4 d AI lb/acre 100 116381

Aphis gossypii Cotton aphid POP POP ABND NOAEL 4 d AI lb/acre 100 116381

Aphis gossypii Cotton aphid POP POP ABND NOAEL 27 d AI lb/acre 100 116381

Aphis gossypii Cotton aphid POP POP ABND NOAEL 27 d AI lb/acre 100 116381

Aphis gossypii Cot ton aphid POP POP ABND NOAEL 27 d AI lb/acre 100 116381

Gossypium hirsutum Cotton POP POP BMAS NOAEL hv AI lb/acre 100 116381

Gossypium hirsutum Cotton POP POP BMAS NOAEL hv AI lb/acre 100 116381

Gossypium hirsutum Cotton POP POP BMAS NOAEL hv AI lb/acre 100 116381

Gossypium hirsutum Cotton POP POP BMAS NOAEL hv AI lb/acre 100 116381

Gossypium hirsutum Cotton POP POP BMAS NOAEL hv AI lb/acre 100 116381

Gossypium hirsutum Cotton POP POP BMAS NOAEL hv AI lb/acre 100 116381

Anabaena flosaquae Blue

- green

algae POP POP BMAS NOEC LOEC 4 d mg/L 85 95681

Microcystis aeruginosa Blue

- green

algae POP POP BMAS NOEC LOEC 4 d mg/L 85 95681

Microcystis flosaquae Blue

- green

algae POP POP BMAS NOEC LOEC 4 d mg/L 85 95681

Chlorella pyren oidosa Green algae POP POP BMAS NOEC LOEC 4 d mg/L 85 95681

Anabaena flosaquae Blue

- green

algae POP POP BMAS MATC 4 d L/mg 85 95681

Microcystis aeruginosa Blue

- green

algae POP POP BMAS MATC 4 d L/mg 85 95681

Microcystis flosaquae Blue

- green

algae PO P POP BMAS MATC 4 d L/mg 85 95681

Chlorella pyrenoidosa Green algae POP POP BMAS MATC 4 d L/mg 85 95681

Claviceps fusiformis Fungus REP REP GERM NOAEL 1 d ppm 100 116052

### 87

Pennisetum glaucum Pearl millet REP REP SSET NOAEL 20 d ppm 100 116052

Pen nisetum glaucum Pearl millet REP REP SSET NOAEL 20 d ppm 100 116052

Pennisetum glaucum Pearl millet REP REP SSET NOAEL 20 d ppm 100 116052

Gossypium hirsutum Cotton POP POP ABND NOAEL LOAEL 55 d lb/acre 100 115843

Gossypium hirsutum Cotton POP POP A BND NOAEL 48 d lb/acre 100 115843

Gossypium hirsutum Cotton POP POP ABND NOAEL 37 d lb/acre 100 115843

Gossypium hirsutum Cotton POP POP ABND NOAEL 29 d lb/acre 100 115843

Gossypium hirsutum Cotton POP POP ABND NOAEL 23 d lb/acre 100 115843

Pen nisetum glaucum Pearl millet GRO MPH HGHT LOAEL 20 d ppm 100 116052

Pennisetum glaucum Pearl millet GRO MPH HGHT LOAEL 20 d ppm 100 116052

Anthonomus grandis Boll Weevil BEH AVO CHEM NOAEL 90 d ppm 100 115845

Anthonomus grandis Boll Weevil BEH AVO CHEM NOAEL 90 d ppm 100 115845

Sclerotinia sclerotiorum Fungus POP POP PGRT NOAEL 4 d ppm 100 115842

Sclerotinia sclerotiorum Fungus POP POP PGRT NOAEL 4 d ppm 100 115842

Sclerotinia sclerotiorum Fungus POP POP PGRT NOAEL 4 d ppm 100 115842

Ec hinochloa oryzicola Rice

Barnyardgrass REP REP GERM NOAEL LOAEL 9 d mg/L 100 31310

Oryza sativa Rice REP REP GERM NOAEL 9 d mg/L 100 31310

Echinochloa oryzicola Rice

Barnyardgrass GRO MPH LGTH NOAEL LOAEL 18 d mg/L 100 31310

Oryza sativa Rice GRO MPH LGTH LOAEL 18 d mg/L 100 31310

NR Chrysopidae Lacewing

family POP POP PRPE NOAEL hv AI g/ha 100 116150

Malus domestica Apple PHY PHY PSYN NOAEL 35 d ppm 100 42817

Malus domestica Apple GRO GRO LGTH LOAEL 14 d ppm 100 42817

Malus domestica App le PHY INJ DAMG NOAEL 35 d ppm 100 42817

Epiphyas postvittana Lightbrown

Apple Moth POP POP ABND NOAEL 35 d ml/L 100 117205

Oryza sativa Rice BCM BCM PNYL LOAEL fi mg/L 100 108344

Oryza sativa Rice BCM BCM PNYL LOAEL fi mg/L 100 108344

Oryz a sativa Rice BCM BCM PNYL LOAEL fi mg/L 100 108344

Oryza sativa Rice REP REP STRL LOAEL fi mg/L 100 108344

Oryza sativa Rice REP REP STRL LOAEL fi mg/L 100 108344

Oryza sativa Rice REP REP STRL LOAEL fi mg/L 100 108344