Date: 

Subject: 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

February 25, 2013 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

FLUOXASTROBIN. Occupational and Residential Exposure Assessment for 

the Proposed Use of Fluoxastrobin on Melons (Subgroup 9-A) and Sorghum and a 

Reevaluation of the Registered Granular Formulation for Residential Use on 

Ornamentals. 

PC Code: 028869 

Decision No.: 465774 

Petition No.: 2F8047 

DP Barcode: D405369 

Registration No.: 66330-64 

Regulatory Action: Section 3 

Risk Assessment Type: Occupational/Residential Exposure Assessment Case No.: NA 

TXR No.: NA CAS No.: 361377-29-9 

MRIDNo.: NA 40 CFR: §180.609 

From: 

Through: 

To: 

Kristin Rury, Biologist ·y_ Q ..---r 

Risk Assessment Branch 3 "' 0 

Health Effects Division (7509P) 

Barry O'Keefe, ORE Team Leader /J .. 0 <){p#n 

Risk Assessment Branch 3 ' . -~ 

Health Effects Division (7509P) 

and 

Jeff Evans 

Bridget Bobowiec ~~ 

Exposure Science Advisory Committee (ExpoSAC) I HED 

Nancy Tsaur, Chemist, Risk Assessor 

Risk Assessment Branch 3 

Health Effects Division (7590P) 

and 

Heather Garvie/Shaja Joyner, RM 20 

Fungicide Branch 

Division (7505P) 

Page I of30 
Introduction 

The Registration Division (RD) requested that the Health Effects Division (HED) conduct an 

exposure and risk assessment for the newly proposed use of fluoxastrobin on melons (subgroup 

9A) and sorghum. In addition, HED is providing a reassessment of the registered residential 

handler use of granular fluoxastrobin on ornamentals (EPA Reg. Nos. 66330-380 and 66330-

407). 

It is HED policy to use the best available data to assess exposure. Several sources of generic 

data were used in this assessment as surrogate data in the absence of chemical-specific data, 

including Pesticide Handlers Exposure Database Version 1.1 (PHED 1.1 ), the Agricultural 

Handler Exposure Task Force (AHETF) database, the Outdoor Residential Exposure Task Force 

(ORETF) database, the Agricultural Reentry Task Force (ARTF) database, and the Residential 

SOPs (Gardens/Trees). Some of these data are proprietary, and subject to the data protection 

provisions of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). 

Note: This memorandum was reviewed by the Exposure Science Advisory Council (ExpoSAC) 

on 02/21/2013. 

Page 2 of30 
Page 3 of 30

Table of Contents

1.0 Executive Summary............................................................................................................. 4

2.0 Risk Assessment Conclusions and Recommendations........................................................ 6

2.1 Summary of Risk Estimates............................................................................................. 6

2.2 Label Recommendations.................................................................................................. 6

2.3 Data Deficiencies and Requirements ............................................................................... 6

3.0 Hazard Characterization....................................................................................................... 8

4.0 Use Profile ........................................................................................................................... 9

5.0 Residential Exposure and Risk Estimates.......................................................................... 10

5.1 Residential Handler Exposure/Risk Estimates............................................................... 10

5.2 Residential Post-application Exposure/Risk Estimates.................................................. 11

5.3 Residential Risk Estimates for Use in Aggregate Assessment ...................................... 12

5.5 Spray Drift...................................................................................................................... 13

5.6 Residential Bystander Post-Application Inhalation Exposure ....................................... 13

6.0 Occupational Exposure and Risk Estimates ...................................................................... 14

6.1 Occupational Handler Exposure/Risk Estimates............................................................ 14

6.2 Occupational Post-application Exposure/Risk Estimates .............................................. 20

6.2.1 Occupational Post-application Inhalation Exposure/Risk Estimates...................... 20

6.2.2 Occupational Post-application Dermal Exposure/Risk Estimates.......................... 20

Appendix A. Summary of Occupational and Residential Non-cancer Algorithms..................... 23
Page 4 of 30

1.0 Executive Summary

Fluoxastrobin is a strobilurin-class fungicide (also termed methoxyacrylates) that controls foliar 

fungal diseases and soilborne/seedling fungal diseases. It works by interrupting mitochondrial 

respiration in plant-pathogenic fungi, thus inhibiting spore germination and mycelial growth.

Arysta LifeScience North America, LLC (Arysta) is proposing a new use of fluoxastrobin on 

melons (subgroup 9-A) and sorghum. The proposed formulated end-use product is labeled under 

the trade name Fluoxastrobin 480 SC Fungicide (EPA Reg. No. 66330-64) and serves as the 

master label for EVITO® 480 SC fungicide, DISARMTM 480 SC Fungicide, and Fluoxastrobin 

480 SC Fungicide Seed Treatment. Fluoxastrobin 480 SC Fungicide is a suspension concentrate 

(SC) formulation containing 40.3% active ingredient (ai) by weight (3.98 lb ai per gallon). 

Furthermore, HED reassessed the currently registered use of granular fluoxastrobin on residential 

ornamentals based on current policies and toxicological endpoints because this scenario had not 

previously been re-evaluated using HED’s 2012 Residential SOPs and changes for body weight 

assumptions. 

Proposed Use Profile

Fluoxastrobin 480 SC Fungicide may be applied as a foliar spray via groundboom, aircraft, 

chemigation, and handheld equipment. The maximum single application rate for melons is 5.7 fl 

oz/A (0.18 lb ai/A) and applications may be repeated on a 7-day interval, up to a maximum 

seasonal application rate of 22.8 fl oz/A (0.72 lb ai/A) per year. The maximum single 

application rate for sorghum is 4.0 fl oz/A (0.12 lb ai/A) and applications may be repeated on a 

14-day interval, up to a maximum seasonal application rate of 8 fl oz/A (0.26 lb ai/A) per year.

The proposed label requires occupational handlers to wear long pants, long sleeves, shoes, socks, 

and chemical resistant gloves. 

Exposure Profile

Based on application rate and label information, exposure is expected to occur for short- and 

intermediate-term durations for occupational handlers. Exposure in residential settings is 

expected to be short-term only. Chronic exposure is not expected for the proposed use patterns. 

Hazard Concerns

A short-term dermal endpoint was not identified. The estimated intermediate-term dermal and 

the estimated short- and intermediate-term inhalation exposures were compared to the oral No 

Observed Adverse Effect Level (NOAEL) of 3.0 mg/kg/day from a 90 day subchronic dog

feeding study. Because this point of departure (POD) is from an oral study, the estimated dermal 

exposures were adjusted by applying a 2.3% dermal absorption factor. Since inhalation 

absorption data are not available, toxicity by the inhalation route is considered to be equivalent to 

the estimated toxicity by the oral route of exposure. This endpoint is not a developmental effect; 

therefore, an 80 kg body weight was used in the calculations. The level of concern (LOC) is a 

margin of exposure (MOE) of 100 (i.e. an MOE < 100 is of concern). Fluoxastrobin is

characterized as “not likely to be carcinogenic” to humans.
Page 5 of 30

Residential Exposures and Risk Estimates

Existing residential uses of fluoxastrobin were recently reassessed by HED to reflect updates to 

HED’s 2012 Residential SOPs along with policy changes for body weight assumptions (N. 

Tsaur, D393846, 05/31/2012 and N. Tsaur, D406106, 10/25/2012), except the use of a granular 

formulation on ornamental plants. There are no registered products that would lead to any 

residential handler or post-application risk estimates of concern. Short-term residential handler 

(inhalation only) MOEs range from 7,300 to 1,100,000 for granular fluoxastrobin use on 

residential turf. Because there is no short-term dermal endpoint, and incidental oral postapplication exposures are not expected from application to ornamental plants, residential postapplication exposure was not assessed for granular application to ornamentals. However, the 

worst-case post-application exposure assessments for existing uses on turf have been presented 

here for reference. 

Residential Scenarios Recommended for use in Aggregate Assessment

The most protective residential exposure risk estimates are included in the aggregate exposure 

assessment. The recommended residential exposure for use in the adult aggregate risk 

assessment reflects dermal and inhalation exposure from hand dispersal of granulars to 

ornamentals (MOE = 7,300). The recommended residential exposure for use in the children 1<2 

years old aggregate assessment reflects hand-to-mouth exposures from post-application exposure 

to liquid applications to turf (MOE = 390). 

Occupational Handler Exposures and Risk Estimates

There is potential for short- and intermediate-term occupational exposure to fluoxastrobin during 

handling (e.g. mixing, loading, application). There are no risk estimates of concern at the 

baseline level of personal protective equipment (PPE); all short-term handler risk estimates 

(inhalation only) resulted in MOEs ranging from 3,400 to 76,000; all intermediate-term handler 

risk estimates (dermal + inhalation) resulted in MOEs ranging from 320 to 21,000. 

Occupational Post-application Exposures and Risk Estimates

There is potential for short- and intermediate-term occupational exposure during post-application 

activities. There is no short-term dermal POD selected for fluoxastrobin. There are no 

intermediate-term dermal post-application risk estimates of concern on day 0 (12 hours after 

application); all scenarios resulted in MOEs greater than the LOC (100) and ranged from 1,400 

to 55,000 on day 0. Based on a quantitative post-application assessment, the 12-hour restricted 

entry interval (REI) on the proposed label is acceptable for melons (subgroup 9-A) and sorghum. 

Based on the Agency's current practices, a quantitative non-cancer occupational post-application 

inhalation exposure assessment was not performed for fluoxastrobin at this time. If new policies 

or procedures are put into place, the Agency may revisit the need for a quantitative occupational 

post-application inhalation exposure assessment for fluoxastrobin.

Human Studies Review

This risk assessment relies in part on data from studies in which adult human subjects were 

intentionally exposed to a pesticide or other chemical. These data, which include studies from 

PHED 1.1, the AHETF database, the Outdoor Residential Exposure Task Force (ORETF) 

database, the ARTF database, and the Residential SOPs (Gardens and Trees), are (1) subject to 
Page 6 of 30

ethics review pursuant to 40 CFR 26, (2) have received that review, and (3) are compliant with 

applicable ethics requirements. For certain studies, the ethics review may have included review 

by the Human Studies Review Board. Descriptions of data sources, as well as guidance on their 

use, can be found at the Agency website1. 

2.0 Risk Assessment Conclusions and Recommendations

2.1 Summary of Risk Estimates

Reassessment of Registered Granular Use on Ornamentals

There are no registered products that would lead to any residential handler or post-application 

risk estimates of concern. Short-term residential handler (inhalation only) MOEs range from 

7,300 to 1,100,000 for granular fluoxastrobin use on residential turf. Residential postapplication exposure was not assessed because there is no short-term dermal endpoint, and 

incidental oral post-application exposures are not expected from application to ornamental 

plants. 

Occupational Handlers

There are no risk estimates of concern at the baseline level of personal protective equipment 

(PPE). All short-term handler risk estimates (inhalation only) resulted in MOEs ranging from 

3,400 to 76,000; all intermediate-term handler risk estimates (dermal + inhalation) resulted in 

MOEs ranging from 320 to 21,000.

Occupational Post-Application

There is no short-term dermal POD selected for fluoxastrobin. Based on a quantitative 

assessment, there are no intermediate-term dermal post-application risk estimates of concern on 

day 0 (12 hours after application); all scenarios resulted in MOEs greater than the LOC (100) and 

ranged from 1,400 to 55,000 on day 0. 

2.2 Label Recommendations 

There are no label recommendations based on the occupational or updated residential exposure 

assessments. 

2.3 Data Deficiencies and Requirements

There are no outstanding data deficiencies or exposure requirements for fluoxastrobin. 

HED recently waived the required subchronic inhalation toxicity study for fluoxastrobin (TXR# 

0056388). The waiver was granted because: (1) fluoxastrobin has low acute inhalation toxicity 

and low volatility; (2) the main target organ is the liver following fluoxastrobin exposure; and (3)

all occupational inhalation MOEs are > 1,000 using a conservative oral POD, except for 

 

1

http://www.epa.gov/pesticides/science/handler-exposure-data.html and 

http://www.epa.gov/pesticides/science/post-app-exposure-data.html
Page 7 of 30

exposure scenarios the Agency considers relatively rare (mixing/loading for granular application 

to sod and hand dispersal of granular formulations to turf by residential handlers). 

Residue Data Requirements

Turf Transferrable Residue Studies

A TTR study is required for fluoxastrobin at this time since the incidental oral hand-to-mouth

MOE for small children is less than 1,000 (MOE = 390, LOC = 100) based on default values for 

the fraction of application rate available for transfer after a liquid application to turf (N. Tsaur, 

D406106, 10/25/2012). 

Dislogeable Foliar Residue (DFR) Studies

Following a foliar application, some pesticide residue remains on the leaves of the target plant 

for an individual to contact and remove from the leaf surface resulting in exposure.2 This is 

represented by a measurement from a standardized sampling method (Iwata, et al., 1977) and is 

referred to as DFR. If no study providing DFR measurements is available for a specific 

pesticide, potential exposure from DFR can be estimated using the application rate and a default 

value for the fraction of application rate available to be dislodged after a foliar application (FAR). 

In accordance with the updated Part 158 data requirements (2007), one or more DFR studies are

required when a pesticide has residential or occupational uses that could result in postapplication dermal exposure. This guidance indicates, however, that OPP may waive the 

requirement for a DFR study for a specific pesticide if, based on a case-by-case estimate of 

potential exposure calculated using the default FAR, there is an adequate margin of safety for the 

potential exposures to DFR of the chemical. In such a circumstance, OPP could reasonably 

determine that the Agency does not need a chemical-specific DFR study to reach the conclusion 

that potential exposures to TTR would not pose an unacceptable risk and therefore that the 

chemical-specific DFR study would not be useful in the Agency’s evaluation.

As part of the recent revision to the Health Effects Division’s 2012 Standard Operating 

Procedures for Residential Pesticide Exposure Assessment, HED analyzed a number of DFR 

studies and selected a new default value for the fraction of the application rate available to be 

dislodged after a foliar application (FAR). This default value is 25% and is based on an analysis 

of 19 DFR studies where the FAR value ranged from 2% to 89%. This value is recommended for 

use in both residential and occupational post-application assessments. Of the analyzed DFR 

studies, the maximum FAR value seen was 89% or 3.6 times higher than the default residue 

transfer value. Therefore, a calculated MOE of approximately 4 times higher than the LOC (i.e., 

an MOE > 400 if the LOC = 100) using the default dislodged residue value should provide an 

adequate margin of safety for any potentially higher residues seen in a chemical-specific DFR 

study. A DFR study is not required for fluoxastrobin at this time based on default values for the 

fraction of application rate available for transfer after a foliar application. All intermediate-term 

occupational dermal MOEs for post-application activities are greater than 4 times the LOC, 

except for detassling and hand harvesting sweet corn grain on the day of application (MOE = 

220). However, detassling and hand harvesting activities for sweet corn would be unlikely to 

occur on the day of application for a continuous period of 1-6 months. In addition, the 

fluoxastrobin label provides guidance on resistance management, including that weeds are 

susceptible to strobilurin resistance, so the total number of applications of fluoxastrobin and 

 

2 Described in more detail in http://www.epa.gov/pesticides/science/post-app-exposure-data.html
Page 8 of 30

other Group 11 fungicides should be limited and alternated with other fungicides. All other 

occupational post-application dermal MOEs are >400. Therefore, a DFR study is not required.

3.0 Hazard Characterization

The toxicological doses and endpoints supporting this label amendment remain unchanged and 

have been summarized in the previous human health risk assessment (DP393842, N. Tsaur, 

06/27/2012).

Acute Toxicity

Table 3.1. Acute Toxicity Profile – Fluoxastrobin (EPA Reg. No. 66330-65).

Guideline No. Study Type MRID Results Toxicity Category

870.1100 Acute oral - rat 45865612 LD50 > 2000 mg/kg III

870.1200 Acute dermal - rat 45865613 LD50 > 2000 mg/kg III

870.1300 Acute inhalation - rat 45865618 LC50 = 4.9 mg/L IV

870.2400 Acute eye irritation - rabbit 45865620 moderate irritant III

870.2500 Acute dermal irritation - rabbit 45865622 not an irritant IV

870.2600 Skin sensitization - guinea pig 45865624 not a sensitizer -

Toxicological PODs Used for Risk Assessment

Table 3.2. Summary of Toxicological Doses and Endpoints for Fluoxastrobin for Use in Dietary, NonOccupational, and Occupational Human Health Risk Assessmentsa

Exposure/ 

Scenario

Point of 

Departure

Uncertainty/

FQPA Safety 

Factors

RfD, PAD, 

Level of 

Concern for 

Risk 

Assessment

Study and Toxicological Effects

Incidental Oral 

Short-Term 

(1-30 days) 

and 

IntermediateTerm (1-6 

months)

NOAEL = 

3.0 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

Residential 

LOC for 

MOE = 100

90-day subchronic dog

LOAEL = M/F 24.8/24.2 mg/kg/day based 

on dose-related reductions in net body weight 

gain and food efficiency in addition to 

toxicity findings in the liver (cholestasis) in 

both sexes, and kidneys (increased relative 

weights in females and degeneration of the 

proximal tubular epithelium in males).

Dermal ShortTerm (1-30 

days)

None: There were no systemic or dermal toxicity findings in a 28-day dermal toxicity study in 

the rat up to the limit dose (1000 mg/kg/day) and there were no developmental or neurotoxicity 

concerns raised in other studies.

Dermal 

IntermediateTerm (1-6 

months)

NOAEL = 

3.0 

mg/kg/day

dermal 

absorption 

factor = 

2.3%

UFA = 10X

UFH = 10X

FQPA SF = 1X

LOC for 

MOE = 100

90-day subchronic dog

LOAEL = M/F 24.8/24.2 mg/kg/day based 

on dose-related reductions in net body weight 

gain and food efficiency in addition to 

toxicity findings in the liver (cholestasis) in 

both sexes, and kidneys (increased relative 

weights in females and degeneration of the 

proximal tubular epithelium in males).
Page 9 of 30

Table 3.2. Summary of Toxicological Doses and Endpoints for Fluoxastrobin for Use in Dietary, NonOccupational, and Occupational Human Health Risk Assessmentsa

Exposure/ 

Scenario

Point of 

Departure

Uncertainty/

FQPA Safety 

Factors

RfD, PAD, 

Level of 

Concern for 

Risk 

Assessment

Study and Toxicological Effects

Inhalation 

Short- Term 

(1-30 days)

and 

IntermediateTerm (1-6 

months)

NOAEL = 

3.0 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

LOC for 

MOE = 100

90-day subchronic dog

LOAEL = M/F 24.8/24.2 mg/kg/day based 

on dose-related reductions in net body weight 

gain and food efficiency in addition to 

toxicity findings in the liver (cholestasis) in 

both sexes, and kidneys (increased relative 

weights in females and degeneration of the 

proximal tubular epithelium in males).

Cancer (oral, 

dermal, 

inhalation)

Classification: “Not likely to be Carcinogenic to Humans.”

Point of Departure (POD) = A data point or an estimated point that is derived from observed dose-response data and

used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human 

exposures. NOAEL = no observed adverse effect level. LOAEL = lowest observed adverse effect level. UF = 

uncertainty factor. UFA = extrapolation from animal to human (interspecies). UFH = potential variation in 

sensitivity among members of the human population (intraspecies). FQPA SF = FQPA Safety Factor. MOE = 

margin of exposure. LOC = level of concern.

Absorption

Since inhalation absorption data are not available, toxicity by the inhalation route is considered 

to be equivalent to the estimated toxicity by the oral route of exposure.

A dermal absorption factor of 2.3% was used for the intermediate-term dermal exposure 

assessment. 

Body Weight

The standard body weight for the general population (80 kg) was used for all exposure scenarios 

covered in this risk assessment since the endpoints selected were not developmental and/or fetal 

effects.

4.0 Use Profile 

Table 4.1. Summary of Proposed Directions for Use of Fluoxastrobin.

Applic. 

Timing, Type, 

and Equip.

Formulation 

[EPA Reg. 

No.]

Applic. 

Rate (fl 

oz/A)

Applic. 

Rate (lb 

ai/A)

Max. No. 

Applic. per 

Season

Max. 

Seasonal 

Applic. Rate 

(lb ai/A)

PHI 

(days)

Use Directions and 

Limitations

Melon (Subgroup 9A)

Ground, Aerial. 

Chemigation, 

Handheld

Liquid 

[66330-64]

Contains 3.98 

lb ai/gal 

product

5.7 fl 

oz/A

0.18

(0.018 lb 

ai/gal)

4 0.72 1

There is a minimum 

interval of 7 days between 

applications.

Do not apply to Subgroup 

9-A crops in a Greenhouse.

Not approved for use in 
Page 10 of 30

Table 4.1. Summary of Proposed Directions for Use of Fluoxastrobin.

Applic. 

Timing, Type, 

and Equip.

Formulation 

[EPA Reg. 

No.]

Applic. 

Rate (fl 

oz/A)

Applic. 

Rate (lb 

ai/A)

Max. No. 

Applic. per 

Season

Max. 

Seasonal 

Applic. Rate 

(lb ai/A)

PHI 

(days)

Use Directions and 

Limitations

California.

Sorghum

Ground, Aerial. 

Chemigation, 

Handheld

Liquid 

[66330-64] 

Contains 3.98 

lb ai/gal 

product

4.0 fl 

oz/A 0.12 2 0.26

21 

(grain & 

stover)

14 

(forage)

There is a minimum 

interval of 14 days between 

applications

Not approved for use in 

California.

5.0 Residential Exposure and Risk Estimates

There are no proposed residential uses at this time; however, there are existing residential uses of 

granular fluoxastrobin on ornamentals that have been reassessed in this document to reflect 

updates to HED’s 2012 Residential SOPs3along with policy changes for body weight 

assumptions. All other residential uses were reassessed using HED’s 2012 Residential SOPs and 

updated body weights in the most recent ORE assessments (N. Tsaur, D393846, 05/31/2012 and 

N. Tsaur, D406106, 10/25/2012). The revision of residential exposures will impact the human 

health aggregate risk assessment for fluoxastrobin.

5.1 Residential Handler Exposure/Risk Estimates

HED uses the term “handlers” to describe those individuals who are involved in the pesticide 

application process. HED believes that there are distinct tasks related to applications and that 

exposures can vary depending on the specifics of each task. Residential handlers are addressed 

somewhat differently by HED as homeowners are assumed to complete all elements of an 

application without use of any PPE.

The quantitative exposure/risk assessment to evaluate the registered uses of granulars on 

ornamentals is based on the following scenarios: 

Applying with a push-type rotary spreader,

Applying with a spoon,

Applying with a cup,

Applying via Hand dispersal, and

Applying with a shaker can.

Residential Handler Exposure Data and Assumptions

A series of assumptions and exposure factors served as the basis for completing the residential 

handler risk assessments. Each assumption and factor is detailed below.

Application Rate: The registered fluoxastrobin labels allow up to 0.0000719 lb ai/ft2for granular 

application to ornamental plants. 

 

3 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 11 of 30

Unit Exposures and Area Treated or Amount Handled: Unit exposure values and estimates for 

area treated or amount handled were taken from HED’s 2012 Residential SOPs4.

Exposure Duration: Residential handler exposure is expected to be short-term in duration. 

Intermediate-term exposures are not likely because of the intermittent nature of applications by 

homeowners. 

Residential Handler Non-Cancer Exposure and Risk Estimate Equations

The algorithms used to estimate exposure and dose for residential handlers can be found in 

Appendix A and/or the 2012 Residential SOPs5.

Combining Exposures/Risk Estimates:

Dermal and inhalation risk estimates were not combined in this assessment, since there is no 

short-term dermal POD. 

Summary of Residential Handler Non-Cancer Exposure and Risk Estimates

There are no registered products that would lead to any residential handler or post-application 

risk estimates of concern. Short-term residential handler (inhalation only) MOEs range from 

7,300 to 1,100,000 for granular fluoxastrobin use on residential turf. 

Table 5.1. Residential Handler Non-cancer Exposure and Risk Estimates for Granular Application of 

Fluoxastroin to Ornamentals.

Exposure Scenario Level of Concern

Inhalation 

Unit 

Exposure

(mg/lb ai)

Maximum 

Application 

Rate (lb 

ai/ft2)

1

Area Treated 

or Amount 

Handled Daily

(ft2)

2

Inhalation

Dose

(mg/kg/day)3 MOE4

Mixer/Loader/Applicator

Applying with Push-type 

Rotary Spreader

100

0.0026

0.0000719 1200

0.0000028 1,100,000

Applying with a Spoon 0.087 0.000094 32,000

Applying with a Cup 0.013 0.000014 210,000

Hand Dispersal 0.38 0.00041 7,300

Applying with a Shaker 

Can 0.013 0.000014 210,000

1 Based on registered label (EPA Reg. No. 66330-380).

2 Based on HED’s 2012 Residential SOPs (http://www.epa.gov/pesticides/science/residential-exposure-sop.html).

3 Inhalation Dose = Inhalation Unit Exposure (mg/lb ai) × Application Rate (lb ai/ft2) × Area Treated or Amount Handled 

(ft2/day) ÷ BW (80 kg).

4 Inhalation MOE = Inhalation NOAEL (mg/kg/day) ÷ Inhalation Dose (mg/kg/day).

5.2 Residential Post-application Exposure/Risk Estimates

There is the potential for post-application exposure for individuals exposed as a result of being in 

an environment that has been previously treated with fluoxastrobin. A quantitative postapplication exposure assessment for granular application to ornamentals has not been included 

 

4 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html

5 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 12 of 30

because of the following reasons: (1) there is no short-term dermal POD for fluoxastrobin, (2) 

intermediate-term post-application is not expected in residential settings, and (3) incidental oral 

ingestion is not expected from applications to ornamentals. 

Since fluoxastrobin is also registered for use on turf, all other residential uses were reassessed 

using HED’s 2012 Residential SOPs and updated body weights in the most recent ORE 

assessments (N. Tsaur, D393846, 05/31/2012 and N. Tsaur, D406106, 10/25/2012).

Table 5.2 presents the worst-case post-application incidental oral MOE values calculated after 

liquid applications of fluoxastrobin to turf for all registered products. Post-application risk 

estimates for all scenarios are not of concern to HED (MOEs range from 390 to 180,000). The 

algorithms used to estimate residential post-application exposure and dose can be found in 

Appendix A and/or the 2012 Residential SOPs6Error! Bookmark not defined..

Table 5.2. Short-Term Residential Post-Application Exposure and Risk Estimates for Fluoxastrobin on Turf.

Lifestage Post-Application Exposure Scenario Dose1

MOEs2

mg/kg/day

Suspension Concentrate (SC) Liquid Formulation

Fluoxastrobin 480 SC Fungicide (EPA Reg. No. 66330-64)

3.69 lb ai/gallon

Max Single Application Rate: 2.13 lb ai/A

From: N. Tsaur, D406106, 10/25/2012

Child 1 to < 2 year old

Hand to Mouth 0.0077 390

Object to Mouth 0.00024 13,000

Incidental Soil Ingestion 0.000017 180,000

1 Hand-to-Mouth Dose = hand residue loading (mg/cm2) × fraction of hand mouthed (0.127) × surface area of 1 hand (150 cm2) 

× exposure time (1.5 hrs/day) × # of replenishment intervals/hr (4 int/hr) × (1-((1-saliva extraction factor (0.5))^(Number of 

hand-to-mouth events per hour (13.9 events/hr) ÷ # of replenishment intervals/hr)) ÷ body weight (11 kg).

Object-to-Mouth Dose = object residue loading (μg/cm2) × unit conversion factor (0.001 mg/μg) × object surface area mouthed

/ event (10 cm2/event) × exposure time (1.5 hrs/day) × # replenishment intervals/hr (4 int/hr) × (1-((1- saliva extraction factor 

(0.50))^(# Object-to-Mouth Events/hr (8.8 events/hr) ÷ # replenishment intervals/hr)) ÷ body weight (11 kg).

Soil Ingestion = soil residue (μg/g) × ingestion rate (50 mg/day) × conversion factor (0.000001 g/μg) ÷ body weight (11 kg).

Granule Ingestion = % ai in the product × ingestion rate (0.3 g/day) × Conversion Factor (1000 mg/g) ÷ body weight (11 kg).

2 MOE = NOAEL ÷ Daily Dose (mg/kg/day). Incidental Oral NOAEL= 3.0 mg/kg/day. Level of concern = 100.

5.3 Residential Risk Estimates for Use in Aggregate Assessment

Table 5.3 reflects the residential risk estimates that are recommended for use in the aggregate 

assessment for fluoxastrobin.

The recommended residential exposure for use in the adult aggregate assessment reflects 

dermal and inhalation exposure from hand dispersal of granulars to ornamentals in 

residential settings. 

The recommended residential exposure for use in the children 1<2 years old aggregate 

assessment reflects hand-to-mouth exposures from post-application exposure from liquid 

applications to turf. 

 

6 Available: http://www.epa.gov/pesticides/science/residential-exposure-sop.html
Page 13 of 30

Table 5.3. Scenarios Recommended for Aggregate Risk Assessment of Fluoxastrobin (Short-Term Only).

Scenario

Daily Dose1,3

MOE2,4

mg/kg/day

Adults 

Residential Handler Inhalation Exposure

(Applying Granulars via Hand Dispersal) 0.00041 7,300

Children (1 to <2 Years Old)

Post-Application Incidental Oral Exposure: Hand-to-Mouth

(After Liquid Application to Turf) 0.0077 390

1 Residential Handler Dose = the highest handler dose for each applicable lifestage of all scenarios assessed from all registered fluoxastrobin 

residential uses – taken from Table 5.1. Total = dermal + inhalation.

2 Residential Handler MOE = the MOEs associated with the highest doses identified in Table 5.1.1. 

3 Residential Post-application Dose = the highest post-application dose for each applicable lifestage of all scenarios assessed from all registered 

fluoxastrobin residential uses - Table 5.2. 

4 Residential Post-application MOE = the MOEs associated with the highest doses identified in Table 5.2. 

5.5 Spray Drift

Spray drift is always a potential source of exposure to residents nearby to spraying operations. 

This is particularly the case with aerial application, but, to a lesser extent, could also be a 

potential source of exposure from the ground application method employed for fluoxastrobin. 

The Agency has been working with the Spray Drift Task Force, EPA Regional Offices and State 

Lead Agencies for pesticide regulation and other parties to develop the best spray drift 

management practices (see the Agency’s Spray Drift website for more information7. The 

Agency has completed its evaluation of the new database submitted by the Spray Drift Task 

Force, a membership of U.S. pesticide registrants, and is developing a policy on how to 

appropriately apply the data and the AgDRIFT computer model to its risk assessments for 

pesticides applied by air, orchard airblast and ground hydraulic methods. After the policy is in 

place, the Agency may impose further refinements in spray drift management practices to reduce 

off-target drift with specific products with significant risk estimates associated with drift.

Although a quantitative residential post-application inhalation exposure assessment was not 

performed as a result of pesticide drift from neighboring treated agricultural fields, an inhalation 

exposure assessment was performed for flaggers. This exposure scenario is representative of a 

worse case inhalation (drift) exposure and may be considered protective of most outdoor 

agricultural and commercial post-application inhalation exposure scenarios. 

5.6 Residential Bystander Post-Application Inhalation Exposure

Based on the Agency's current practices, a quantitative post-application inhalation exposure 

assessment was not performed for fluoxastrobin at this time primarily because of the low acute 

inhalation toxicity (Toxicity Category IV), low vapor pressure (4.2 x 10-12 mm Hg at 20 °C), and 

the low proposed use rate (0.18 lb ai/A). However, volatilization of pesticides may be a source 

of post-application inhalation exposure to individuals nearby pesticide applications. The Agency 

sought expert advice and input on issues related to volatilization of pesticides from its Federal 

Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, 

 

7 Available: http://www.epa.gov/opp00001/factsheets/spraydrift.htm 
Page 14 of 30

and received the SAP’s final report on March 2, 20108. The Agency is in the process of 

evaluating the SAP report and may, as appropriate, develop policies and procedures to identify 

the need for and, subsequently, the way to incorporate post-application inhalation exposure into 

the Agency's risk assessments. If new policies or procedures are developed, the Agency may 

revisit the need for a quantitative post-application inhalation exposure assessment for 

fluoxastrobin.

6.0 Occupational Exposure and Risk Estimates

6.1 Occupational Handler Exposure/Risk Estimates

HED uses the term handlers to describe those individuals who are involved in the pesticide 

application process. HED believes that there are distinct job functions or tasks related to 

applications and exposures can vary depending on the specifics of each task. Job requirements 

(amount of chemical used in each application), the kinds of equipment used, the target being 

treated, and the level of protection used by a handler can cause exposure levels to differ in a 

manner specific to each application event. 

Based on the anticipated use patterns and current labeling, types of equipment and techniques 

that can potentially be used, occupational handler exposure is expected from the proposed uses. 

The quantitative exposure/risk assessment developed for occupational handlers is based on the 

following scenarios: 

Mixing/Loading liquids for aerial, chemigation, and groundboom application

Applying liquids with aerial and groundboom equipment, and

Mixing/Loading/Applying with a mechanically pressurized handgun.

Occupational Handler Exposure Data and Assumptions

A series of assumptions and exposure factors served as the basis for completing the occupational 

handler risk assessments. Each assumption and factor is detailed below on an individual basis.

Application Rate: All proposed application rates are provided in Table 4.1.

Unit Exposures: It is the policy of HED to use the best available data to assess handler exposure. 

Sources of generic handler data, used as surrogate data in the absence of chemical-specific data, 

include PHED 1.1, the AHETF database, the Outdoor Residential Exposure Task Force 

(ORETF) database, or other registrant-submitted occupational exposure studies. Some of these 

data are proprietary (e.g., AHETF data), and subject to the data protection provisions of FIFRA. 

The standard values recommended for use in predicting handler exposure that are used in this 

assessment, known as “unit exposures”, are outlined in the “Occupational Pesticide Handler Unit 

Exposure Surrogate Reference Table9”, which, along with additional information on HED policy 

on use of surrogate data, including descriptions of the various sources, can be found at the 

Agency website10.

 

8 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html

9 Available: http://www.epa.gov/opp00001/science/handler-exposure-table.pdf

10 Available: http://www.epa.gov/pesticides/science/handler-exposure-data.html
Page 15 of 30

Area Treated or Amount Handled: Based on HED ExpoSAC Policy 9.1, the amount treated or 

handled per day was assumed to be: 

350 acres for mixing/loading for aerial application to melons (subgroup 9A),

1200 acres for mixing/loading for aerial application to sorghum, 

350 acres for mixing/loading for chemigation application to melons and sorghum, 

80 acres for mixing/loading for groundboom application to melons (subgroup 9A), 

200 acres for mixing/loading for groundboom application to sorghum, 

350 acres for aerial applications, and

1000 gallons for applications using a mechanically pressurized handgun to melons 

(subgroup 9-A). 

Exposure Duration: HED classifies exposures from 1 to 30 days as short-term and exposures 30 

days to six months as intermediate-term. Exposure duration is determined by many things, 

including the exposed population, the use site, the pest pressure triggering the use of the 

pesticide, and the cultural practices surrounding that use site. For most agricultural uses, it is 

reasonable to believe that occupational handlers will not apply the same chemical every day for 

more than a one-month time frame; however, there may be a large agribusiness and/or 

commercial applicators who may apply a product over a period of weeks (e.g., completing 

multiple applications for multiple clients within a region). 

For fluoxastrobin, based on the proposed use, short- and intermediate-term exposure(s) are

expected because repeated applications may be made to the proposed crops (up to 4 applications 

per season). Additionally, since the same POD was selected for both short- and intermediateterm inhalation exposures, the quantitative occupational exposure assessment is protective of 

both exposure durations. There was no short-term dermal POD selected for fluoxastrobin; 

therefore, only intermediate-term dermal exposure was quantitatively assessed. 

Mitigation/Personal Protective Equipment: Estimates of dermal and inhalation exposure were 

calculated for various levels of PPE. Results are presented for “baseline,” defined as a single 

layer of clothing consisting of a long sleeved shirt, long pants, shoes plus socks, no protective 

gloves, and no respirator, as well as baseline with various levels of PPE as necessary (e.g., 

gloves, respirator, etc). The fluoxastrobin product labels direct mixers, loaders, applicators and 

other handlers to wear long sleeved shirts, long pants, shoes, socks, and chemical resistant 

gloves. 

HED recommends that RD ensure the appropriate safety directions and re-entry restrictions are 

included in the label.

Occupational Handler Non-Cancer Exposure and Risk Estimate Equations

The algorithms used to estimate non-cancer exposure and dose for occupational handlers can be 

found in Appendix A.

Combining Exposures/Risk Estimates:

Only inhalation exposure was assessed for short-term durations because no short-term dermal 

POD was selected for fluoxastrobin. Intermediate-term dermal and inhalation risk estimates

were combined in this assessment, since the toxicological effects for these exposure routes were 
Page 16 of 30

the same. Intermediate-term dermal and inhalation risk estimates were combined using the 

following formula:

Total MOE = Point of Departure (mg/kg/day) ÷ Combined dermal + inhalation dose (mg/kg/day)

Summary of Occupational Handler Non-Cancer Exposure and Risk Estimates

There are no risk estimates of concern at the baseline level of personal protective equipment 

(PPE); all short-term handler risk estimates (inhalation only) resulted in MOEs ranging from 

3,400 to 76,000; all intermediate-term handler risk estimates (dermal + inhalation) resulted in 

MOEs ranging from 320 to 21,000.

The Agency matches quantitative occupational exposure assessment with appropriate 

characterization of exposure potential. While HED presents quantitative risk estimates for human 

flaggers where appropriate, agricultural aviation has changed dramatically over the past two 

decades. According the 2012 National Agricultural Aviation Association (NAAA) survey of 

their membership, the use of GPS for swath guidance in agricultural aviation has grown steadily 

from the mid 1990’s. Over the same time period, the use of human flaggers for aerial pesticide 

applications has decreased steadily from ~15% in the late 1990’s to only 1% in the most recent 

(2012) NAAA survey. The Agency will continue to monitor all available information sources to 

best assess and characterize the exposure potential for human flaggers in agricultural aerial 

applications.

HED has no data to assess exposures to pilots using open cockpits. The only data available is for 

exposure to pilots in enclosed cockpits. Therefore, risks to pilots are assessed using the 

engineering control (enclosed cockpits) and baseline attire (long-sleeve shirt, long pants, shoes, 

and socks); per the Agency’s Worker Protection Standard stipulations for engineering controls, 

pilots are not required to wear protective gloves for the duration of the application. With this 

level of protection, there are no risk estimates of concern for applicators.

Table 6.1.1. Occupational Handler Short-Term Non-Cancer Exposure and Risk Estimates for Fluoxastrobin.

Exposure Scenario Crop or Target

Inhalation Unit 

Exposure (μg/lb ai)1 Maximum

Application 

Rate2

Area 

Treated or 

Amount 

Handled 

Daily3

Inhalation

Baseline (No 

Respirator) Dose (mg/kg/day)4 MOE5

Mixer/Loader

Mixing/Loading for 

Aerial Application

Melon (subgroup 

9A) 0.219 0.18 lb ai/A 350 0.000173 17,000

Sorghum 0.219 0.12 lb ai/A 1200 0.000394 7,600

Mixing/Loading for 

Chemigation 

Application

Melon (subgroup 

9A) 0.219 0.18 lb ai/A 350 0.000173 17,000

Sorghum 0.219 0.12 lb ai/A 350 0.000115 26,000

Mixing/Loading for 

Groundboom 

Application

Melon (subgroup 

9A) 0.219 0.18 lb ai/A 80 0.0000394 76,000

Sorghum 0.219 0.12 lb ai/A 200 0.0000658 46,000

Applicator
Page 17 of 30

Table 6.1.1. Occupational Handler Short-Term Non-Cancer Exposure and Risk Estimates for Fluoxastrobin.

Exposure Scenario Crop or Target

Inhalation Unit 

Exposure (μg/lb ai)1 Maximum

Application 

Rate2

Area 

Treated or 

Amount 

Handled 

Daily3

Inhalation

Baseline (No 

Respirator) Dose (mg/kg/day)4 MOE5

Applying with Aerial 

Equipment

Melon (subgroup 

9A) 0.068 0.18 lb ai/A 350 0.0000535 56,000

Sorghum 0.068 0.12 lb ai/A 1200 0.000122 25,000

Applying with 

Groundboom

Melon (subgroup 

9A) 0.34 0.18 lb ai/A 80 0.0000613 49,000

Sorghum 0.34 0.12 lb ai/A 200 0.000102 29,000

Flagger

Flagging for Aerial 

Application

Melon (subgroup 

9A) 0.35 0.18 lb ai/A 350 0.000276 11,000

Sorghum 0.35 0.12 lb ai/A 350 0.000184 16,000

Mixer/Loader/Applicator

Mixing/Loading/Appl

ying for Broadcast 

Application with 

Mechanically 

Pressurized Handgun

Melon (subgroup 

9A) 3.9 0.018 lb ai/gal 1000 0.000878 3,400

Mixing/Loading/Appl

ying for 

Drench/Soil/Ground 

Directed Application 

with Mechanically 

Pressurized Handgun

Melon (subgroup 

9A) 3.9 0.018 lb ai/gal 1000 0.000878 3,400

1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (March 2012); Level of mitigation: Baseline. Aerial 

Application is in a closed system at baseline level of PPE. 

2 Based on registered or proposed label (Reg. No. 66330-64).

3 Exposure Science Advisory Council Policy #9.1.

4 Inhalation Dose = Inhalation Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb ai/acre or gal) × Area Treated 

or Amount Handled Daily (A or gal/day) ÷ BW (80 kg).

5 Inhalation MOE = Inhalation NOAEL (3.0 mg/kg/day) ÷ Inhalation Dose (mg/kg/day).
Page 18 of 30

Table 6.1.2. Occupational Handler Intermediate-Term Non-Cancer Exposure and Risk Estimates for Fluoxastrobin.

Exposure Scenario Crop or Target

Dermal Unit 

Exposure (μg/lb 

ai)1

Inhalation Unit 

Exposure (μg/lb 

ai)1

Maximum 

Applicatio

n Rate2

Area 

Treated or 

Amount 

Handled 

Daily3

Dermal Inhalation Total

Mitigation Level Mitigation Level Dose 

(mg/kg/day)4 MOE5 Dose (mg/kg/day)6 MOE7 MOE8

Mixer/Loader

Mixing/Loading for Aerial 

Application

Melon 

(subgroup 9A) 220 0.219 0.18 lb ai/A 350 0.0040 750 0.000173 17,000 720

Sorghum 220 0.219 0.12 lb ai/A 1200 0.00911 330 0.000394 7,600 320

Mixing/Loading for 

Chemigation Application

Melon 

(subgroup 9A) 220 0.219 0.18 lb ai/A 350 0.0040 750 0.000173 17,000 720

Sorghum 220 0.219 0.12 lb ai/A 350 0.00266 1,100 0.000115 26,000 1,100

Mixing/Loading for 

Groundboom Application

Melon 

(subgroup 9A) 220 0.219 0.18 lb ai/A 80 0.000911 3,300 0.0000394 76,000 3,200

Sorghum 220 0.219 0.12 lb ai/A 200 0.00152 2,000 0.0000658 46,000 1,900

Applicator

Applying with Aerial 

Equipment

Melon 

(subgroup 9A) 5 0.068 0.18 lb ai/A 350 0.0000905 33,000 0.0000535 56,000 21,000

Sorghum 5 0.068 0.12 lb ai/A 1200 0.000207 14,000 0.000122 25,000 9,000

Applying with Groundboom

Melon 

(subgroup 9A) 78.6 0.34 0.18 lb ai/A 80 0.000325 9,200 0.0000613 49,000 7,700

Sorghum 78.6 0.34 0.12 lb ai/A 200 0.00054 5,500 0.000102 29,000 4,600

Flagger

Flagging for Aerial 

Application

Melon 

(subgroup 9A) 11 0.35 0.18 lb ai/A 350 0.000199 15,000 0.000276 11,000 6,300

Sorghum 11 0.35 0.12 lb ai/A 350 0.000133 23,000 0.000184 16,000 9,400

Mixer/loader/Applicator

Mixing/Loading/Applying for 

Broadcast Application with 

Mechanically Pressurized 

Handgun

Melon 

(subgroup 9A) 1,300 3.9 0.018 lb ai/gal 1,000 gal 0.00673 450 0.000878 3,400 400

Mixing/Loading/Applying for 

Drench/Soil/Ground Directed 

Application with 

Mechanically Pressurized 

Melon 

(subgroup 9A) 1,300 3.9 0.018 lb ai/gal 1,000 gal 0.00673 450 0.000878 3,400 400
Page 19 of 30

Table 6.1.2. Occupational Handler Intermediate-Term Non-Cancer Exposure and Risk Estimates for Fluoxastrobin.

Exposure Scenario Crop or Target

Dermal Unit 

Exposure (μg/lb 

ai)1

Inhalation Unit 

Exposure (μg/lb 

ai)1

Maximum 

Applicatio

n Rate2

Area 

Treated or 

Amount 

Handled 

Daily3

Dermal Inhalation Total

Mitigation Level Mitigation Level Dose 

(mg/kg/day)4 MOE5 Dose (mg/kg/day)6 MOE7 MOE8

Handgun

1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (March 2012); Level of mitigation: Baseline. Aerial Application is in a closed system at baseline level of 

PPE. 

2 Based on registered or proposed label (Reg. No. 66330-64).

3 Exposure Science Advisory Council Policy #9.1.

4 Dermal Dose = Dermal Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb ai/acre or gal) × Area Treated or Amount Handled (A or gal/day) × DAF (%) ÷ BW (80 

kg).

5 Dermal MOE = Dermal NOAEL (3.0 mg/kg/day) ÷ Dermal Dose (mg/kg/day).

6 Inhalation Dose = Inhalation Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb ai/acre or gal) × Area Treated or Amount Handled (A or gal/day) ÷ BW (80 kg).

7 Inhalation MOE = Inhalation NOAEL (3.0 mg/kg/day) ÷ Inhalation Dose (mg/kg/day).

8 Total MOE = NOAEL (3.0 mg/kg/day) ÷ Dermal Dose + Inhalation Dose.
Page 20 of 30

6.2 Occupational Post-application Exposure/Risk Estimates

HED uses the term post-application to describe exposures that occur when individuals are 

present in an environment that has been previously treated with a pesticide (also referred to as reentry exposure). Such exposures may occur when workers enter previously treated areas to 

perform job functions, including activities related to crop production, such as scouting for pests 

or harvesting. Post-application exposure levels vary over time and depend on such things as the 

type of activity, the nature of the crop or target that was treated, the type of pesticide application, 

and the chemical’s degradation properties. In addition, the timing of pesticide applications, 

relative to harvest activities, can greatly reduce the potential for post-application exposure.

6.2.1 Occupational Post-application Inhalation Exposure/Risk Estimates

Based on the Agency's current practices, a quantitative post-application inhalation exposure 

assessment was not performed for fluoxastrobin at this time primarily because of the low acute 

inhalation toxicity (Toxicity Category IV), low vapor pressure (4.2 x 10-12 mm Hg at 20 °C), and 

the low proposed use rate (0.18 lb ai/A). However, there are multiple potential sources of postapplication inhalation exposure to individuals performing post-application activities in 

previously treated fields. These potential sources include volatilization of pesticides and 

resuspension of dusts and/or particulates that contain pesticides. The Agency sought expert 

advice and input on issues related to volatilization of pesticides from its Federal Insecticide, 

Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and 

received the SAP’s final report on March 2, 201011. The Agency is in the process of evaluating 

the SAP report as well as available post-application inhalation exposure data generated by the 

ARTF and may, as appropriate, develop policies and procedures, to identify the need for and, 

subsequently, the way to incorporate occupational post-application inhalation exposure into the 

Agency's risk assessments. If new policies or procedures are put into place, the Agency may 

revisit the need for a quantitative occupational post-application inhalation exposure assessment 

for fluoxastrobin.

Although a quantitative occupational post-application inhalation exposure assessment was not 

performed, an inhalation exposure assessment was performed for occupational/commercial 

handlers. Handler exposure resulting from application of pesticides outdoors is likely to result in 

higher exposure than post-application exposure. Therefore, it is expected that these handler 

inhalation exposure estimates would be protective of most occupational post-application 

inhalation exposure scenarios.

6.2.2 Occupational Post-application Dermal Exposure/Risk Estimates

Occupational Post-application Dermal Exposure Data and Assumptions

A series of assumptions and exposure factors served as the basis for completing the occupational 

post-application risk assessments. Each assumption and factor is detailed below on an individual 

basis.

 

11 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html
Page 21 of 30

Exposure Duration: HED classifies exposures from 1 to 30 days as short-term and exposures 30 

days to six months as intermediate-term. For fluoxastrobin, based on the proposed use, both

short-and intermediate-term post-application exposures are expected. The use pattern indicates 

that repeated applications are allowed, and hand-setting irrigation and scouting may allow for 

continuous exposure. Additionally, there was no short-term dermal POD selected for 

fluoxastrobin; therefore, only intermediate-term post-application exposure has been 

quantitatively assessed.

Transfer Coefficients: It is the policy of HED to use the best available data to assess postapplication exposure. Sources of generic post-application data, used as surrogate data in the 

absence of chemical-specific data, are derived from ARTF exposure monitoring studies, and, as 

proprietary data, are subject to the data protection provisions of FIFRA. The standard values 

recommended for use in predicting post-application exposure that are used in this assessment, 

known as “transfer coefficients”, are presented in the ExpoSAC Policy 312” which, along with 

additional information about the ARTF data, can be found at the Agency website13.

Table 6.2.2.1. Anticipated Post-Application Activities and Dermal Transfer Coefficients.

Proposed Crops Policy Crop 

Group Category

Transfer 

Coefficients 

(cm2/hr)

Activities

Cantaloupe, Watermelon Vegetables, 

Cucurbits

1900 Hand-Set Irrigation

550 Hand Harvesting, Mechanically Assisted 

Harvesting, Turning

230 Transplanting

90 Scouting, Hand Weeding, Hand Pruning, 

Thinning Fruit

Sorghum Field/row crop, tall

210 Scouting

70 Hand Weeding

Application Rate: All proposed application rates are provided in Table 4.1.

Exposure Time: The average occupational workday is assumed to be 8 hours. 

Dislodgeable Foliar Residues: Chemical-specific dislodgeable foliar residue data have not been 

submitted for fluoxastrobin. Therefore, this assessment uses HED’s default assumption that 25% 

of the application is available for transfer on day 0 following the application and the residues 

dissipate at a rate of 10% each following day.

Occupational Post-application Non-Cancer Intermediate-Term Dermal Exposure and Risk 

Estimate Equations

 

12 Available: http://www.epa.gov/pesticides/science/exposac_policy3.pdf

13 Available: http://www.epa.gov/pesticides/science/post-app-exposure-data.html
Page 22 of 30

The algorithms used to estimate non-cancer exposure and dose for occupational post-application 

workers can be found in Appendix A.

Occupational Post-application Non-Cancer Intermediate-Term Dermal Risk Estimates

There are no intermediate-term dermal post-application risk estimates of concern on day 0 (12 

hours after application); all scenarios resulted in MOEs greater than the LOC (100) and ranged 

from 1,400 to 55,000. 

Table 6.2.2.2. Occupational Post-application Non-Cancer Intermediate-Term Exposure and Risk Estimates

for Fluoxastrobin.

Crop/Site Activities Transfer Coefficient 

(cm2/hr) DFR/TTR1 Dermal Dose (mg/kg/day)2 MOE3

Intermediate-term

Cantaloupe, 

Watermelon

Hand-Set Irrigation 1900 0.505 0.00221 1,400

Hand Harvesting, 

Mechanically Assisted 

Harvesting, Turning

550 0.505 0.000639 4,700

Transplanting 230 0.505 0.000267 11,000

Scouting, Hand Weeding, 

Hand Pruning, Thinning 

Fruit

90 0.505 0.000105 29,000

Sorghum

Scouting 210 0.337 0.000163 18,000

Hand Weeding 70 0.337 0.0000543 55,000

1 DFR = Application Rate × F × (1-D)t × 4.54E8 μg/lb × 2.47E-8 acre/cm2; where F = 0.25 and D = 0.10 per day. 

2 Daily Dermal Dose = [DFR (μg/cm2) × Transfer Coefficient × 0.001 mg/μg × 8 hrs/day × dermal absorption (%)] BW (80 kg).

3 MOE = POD (mg/kg/day) / Daily Dermal Dose. Daily Dermal Dose = [DFR/TTR (μg/cm2) × TC × 0.001 mg/μg × 8 hrs/day × dermal 

absorption factor (%)] BW (80 kg).

Restricted Entry Interval

The REI specified on the proposed label is based on the acute toxicity of fluoxastrobin. 

Fluoxastrobin is classified as Toxicity Category III via the dermal route and Toxicity Category 

IV for skin irritation potential. It is not a skin sensitizer. Short- and intermediate-term postapplication risk estimates were not a concern on day 0 (12 hours following application) for all 

post-application activities. Under 40 CFR 156.208 (c) (2) (iii), ai’s classified as Acute III or IV 

for acute dermal, eye irritation and primary skin irrigation are assigned a 12-hour REI. 

Therefore, the [156 subpart K] Worker Protection Statement interim REI of 12 hours is adequate 

to protect agricultural workers from post-application exposures to fluoxastrobin. Therefore, the 

proposed REI is adequate. 
Page 23 of 30

Appendix A. Summary of Occupational and Residential Non-cancer Algorithms

Residential Non-cancer Handler Algorithms

Dermal and Inhalation Handler Exposure Algorithm

Daily dermal and inhalation exposure (mg/day) for residential pesticide handlers, for a given 

formulation-application method combination, is estimated by multiplying the formulationapplication method-specific unit exposure by an estimate of the amount of active ingredient 

handled in a day, using the equation below:

E = UE * AR * A

where:

E = exposure (mg/day);

UE = unit exposure (mg/lb ai);

AR = application rate (e.g., lb ai/ft2, lb ai/gal); and

A = area treated or amount handled (e.g., ft2/day, gal/day).

Residential Non-cancer Post-application Algorithms

Post-application Dermal Exposure Algorithm – Physical Activities on Turf

Exposure resulting from contacting previously treated turf while performing physical activities is 

calculated as shown below. Residential post-application exposure assessment must include 

calculation of exposure on the day of application. Therefore, though an assessment can present 

exposures for any day “t” following the application, it must include “day 0” exposure.

E = TTRt * CF1 * TC * ET

where:

E = exposure (mg/day);

TTRt = turf transferable residue on day t (μg/cm2);

CF1 = weight unit conversion factor (0.001 mg/μg);

TC = transfer coefficient (cm2/hr); and

ET = exposure time (hr/day).

If chemical-specific TTR data are available, then surface residues from the day of application 

should be used (assume that individuals could be exposed to residues immediately after 

application). However, if data are not available, then TTRt can be calculated using the following 

formula:

TTRt= AR * F * (1-FD)t * CF2 * CF3

where:
Page 24 of 30

TTRt = turf transferable residue on day t (μg/cm2);

AR = application rate (lbs ai/ft2or lb ai/acre);

F = fraction of ai as transferable residue following application (unitless);

FD = fraction of residue that dissipates daily (unitless);

t = post-application day on which exposure is being assessed;

CF2 = weight unit conversion factor (4.54 x 108μg/lb); and

CF3 = area unit conversion factor (1.08 x 10-3ft2/ cm2or 2.47 x 10-8acre/cm2).

Dermal absorbed doses are calculated as:

BW

E AF D*

where:

D = dose (mg/kg-day);

E = exposure (mg/day);

AF = absorption factor (dermal); and

BW = body weight (kg).

Table A-X: Turf (Physical Activities) -- Inputs for Residential Post-application Dermal Exposure

Algorithm Notation Exposure Factor

(units) Point Estimate(s)

AR Application rate

(mass active ingredient per unit area) [input]

F

Fraction of AR as TTR 

following application (if 

chemical-specific data is 

unavailable)

L/WP/WDG 0.01

Granules 0.002

FD

Daily residue dissipation 

(if chemical-specific data 

is unavailable)

(fraction)

L/WP/WDG 0.1

Granules 0.1

TC

Transfer 

Coefficient 

(cm2/hr)

L/WP/WDG

Adults 180,000

Children 1 < 2 years old 49,000

Granules

Adults 200,000

Children 1 < 2 years old 54,000

ET Exposure Time

(hours per day)

Adults 1.5

Children 1 < 2 years old 1.5

BW Body Weight

(kg)

Adults 80

Children 1 < 2 years old 11

L/WP/WDG = Liquids/Wettable Powders/Water-dispersible Granules

Post-application Hand-to-Mouth Exposure Algorithm– Physical Activities on Turf

Exposure from hand-to-mouth activity is calculated as follows (based on the algorithm utilized in 

the SHEDS-Multimedia model):

E = [HR * (FM * SAH) * (ET * N_Replen) * (1- (1- SE)

(Freq_HtM/N-Replen))]
Page 25 of 30

where:

E = exposure (mg/day);

HR = hand residue loading (mg/cm2);

FM = fraction hand surface area mouthed / event (fraction/event);

SAH = typical surface area of one hand (cm2);

ET = exposure time (hr/day);

N_Replen = number of replenishment intervals per hour (intervals/hour);

SE = saliva extraction factor (i.e., mouthing removal efficiency); and

Freq_HtM = number of hand-to-mouth contacts events per hour (events/hour).

and

SA * 2

Fai *DE

HR

H

hands

where:

HR = hand residue loading (mg/cm2);

Faihands = fraction ai on hands compared to total surface residue from dermal transfer coefficient 

study (unitless);

DE = dermal exposure (mg); and

SAH = typical surface area of one hand (cm2).

Dose, normalized to body weight, is calculated as:

BW

E

D

where:

D = dose (mg/kg-day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A-X: Turf (Physical Activities) – Inputs for Residential Post-application Hand-to-Mouth Exposure 

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

Faihands

Fraction of ai on hands 

from dermal transfer 

coefficient study

(unitless)

Liquid formulations 0.06

Granular formulations 0.027

DE Dermal exposure (mg) Calculated

SAH

Typical surface area of one hand (cm2), children 1 < 

2 years old 150

AR Application rate

(mass active ingredient per unit area) [input]

HR Residue available on the hands (mg/cm2) Calculated via (DE * Faihands)/SAH
Page 26 of 30

Table A-X: Turf (Physical Activities) – Inputs for Residential Post-application Hand-to-Mouth Exposure 

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

FM

Fraction hand surface area mouthed

(fraction/event) 0.127

N_Replen Replenishment intervals per hour

(intervals/hr) 4

ET Exposure time 

(hrs/day) 1.5

SE Saliva extraction factor

(unitless) 0.48

Freq_HtM Hand-to-mouth events per hour

(events/hr) 13.9

BW Body Weight

(kg) Children 1 < 2 years old 11

Post-application Object-to-Mouth Exposure Algorithm– Physical Activities on Turf

Exposure from object-to-mouth activity is calculated as follows (based on the algorithm utilized 

in SHEDS-Multimedia):

E = [OR* CF1 * SAMO * (ET * N_Replen) * (1- (1- SEO)

(Freq_OtM/N_Replen))]

where:

E = exposure (mg/day);

OR = chemical residue loading on the object on day “t” (ug/cm2);

CF1 = weight unit conversion factor (0.001 mg/μg);

SAMO = area of the object surface that is mouthed (cm2/event);

ET = exposure time (hr/day);

N_Replen = number of replenishment intervals per hour (intervals/hour);

SEO = saliva extraction factor (i.e., mouthing removal efficiency); and

Freq_OtM = number of object-to-mouth contact events per hour (events/hour).

and

OR = AR * FO * CF2 * CF3

where:

OR = chemical residue loading on the object (μg/cm2);

AR = application rate (lbs ai/ft2or lb ai/acre);

FO = fraction of residue available on the object (unitless);

CF2 = weight unit conversion factor (4.54 x 108μg/lb); and

CF3 = area unit conversion factor (1.08 x 10-3ft2/cm2or 2.47 x 10-8acre/cm2).

Dose, normalized to body weight, is calculated as:
Page 27 of 30

BW

E

D

where:

D = dose (mg/kg-day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A-X: Turf (Physical Activities) – Inputs for Residential Post-application Object-to-Mouth Exposure 

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

AR Application rate (to turf)

(mass active ingredient per unit area) [input]

FO Fraction of AR as OR following application 10.01

SAMO

Surface area of object mouthed 

(cm2/event) 10

N_Replen Replenishment intervals per hour (intervals/hour) 4

SEO

Saliva extraction factor

(fraction) 0.48

ET Exposure time 

(hours per day) 1.5

Freq_OtM Object-to-mouth events per hour (events/hr) 8.8

BW Body Weight (kg) Children 1 < 2 years old 11

1 This SOP assumes that all of the residue on the turf could be transferred to the object (e.g., object residue is 

equal to turf transferable residue).

Post-application Incidental Soil Ingestion Exposure Algorithm– Physical Activities on Turf

Exposure from incidental soil ingestion is calculated as follows:

E = SRt * SIgR * CF1

where:

E = exposure (mg/day);

SRt = soil residue on day "t" (μg/g);

SIgR = ingestion rate of soil (mg/day); and

CF1 = weight unit conversion factor (1 x 10-6g/μg).

and

SRt = AR * FS * (1-FD)

t

* CF2 * CF3 * CF4

where:

SRt = soil residue on day "t" (μg/g);

AR = application rate (lbs ai/ft2or lb ai/acre);

FS = fraction of ai available in uppermost cm of soil (fraction/cm);

FD = fraction of residue that dissipates daily (unitless);

T = post-application day on which exposure is being assessed;
Page 28 of 30

CF2 = weight unit conversion factor (4.54 x 108μg/lb);

CF3 = area unit conversion factor (1.08 x 10-3ft2/cm2 or 2.47 x 10-8acre/cm2); and

CF4 = soil volume to weight unit conversion factor (0.67 cm3/g soil).

Dose, normalized to body weight, are calculated as:

BW

E

D

where:

D = dose (mg/kg-day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A-X: Turf (Physical Activities) – Inputs for Residential Post-application Incidental Soil Ingestion 

Exposure 

Algorithm 

Notation

Exposure Factor

(units) Point Estimate(s)

AR Application rate

(mass active ingredient per unit area) [input]

FS Fraction of AR available in uppermost 1 cm of soil

(unitless) 1

FD

Daily residue dissipation

(fraction) 0.1

SIgR Soil ingestion rate (mg/day) 50

BW Body weight (kg) Children 1 < 2 years old 11

Occupational Non-cancer Handler Algorithms

Potential daily exposures for occupational handlers are calculated using the following formulas:

where:

E = exposure (mg ai/day),

UE = unit exposure (μg ai/lb ai),

AR = maximum application rate according to proposed label (lb ai A or lb ai/gal), and

A = area treated or amount handled (e.g., A/day, gal/day).

The daily doses are calculated using the following formula:

where:
Page 29 of 30

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day),

E = exposure (mg ai/day),

AF = absorption factor (dermal and/or inhalation), and

BW = body weight (kg).

Margin of Exposure: Non-cancer risk estimates for each application handler scenario are 

calculated using a Margin of Exposure (MOE), which is a ratio of the toxicological endpoint to 

the daily dose of concern. The daily dermal and inhalation dose received by occupational 

handlers are compared to the appropriate POD (i.e., NOAEL) to assess the risk to occupational 

handlers for each exposure route. All MOE values are calculated using the following formula:

where:

MOE = margin of exposure: value used by HED to represent risk estimates (unitless),

POD = point of departure (mg/kg/day), and

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day).

Occupational Non-cancer Post-application Algorithms

Potential daily exposures for occupational post-application workers are calculated using the 

following formulas:

where:

DFRt = dislodgeable foliage residue on day "t" (μg/cm2),

AR = application rate (lb ai/acre),

F = fraction of ai retained on foliage or 25% (unitless),

D = fraction of residue that dissipates daily or 10% (unitless), and

t = number of days after application day (days).

where:

E = exposure (mg ai/day),

TC = transfer coefficient (cm2/hr),

DFRt = dislodgeable foliar residue on day “t” (μg/cm2), and

ET = exposure time (hours/day).
Page 30 of 30

The daily doses are calculated using the following formula:

where:

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day),

E = exposure (mg ai/day),

AF = absorption factor (dermal and/or inhalation), and

BW = body weight (kg).

Margin of Exposure: Non-cancer risk estimates for each scenario are calculated using a Margin 

of Exposure (MOE), which is a ratio of the toxicological endpoint to the daily dose of concern. 

The daily dermal dose received by occupational post-application workers is compared to the 

appropriate POD (i.e., NOAEL) to assess the risk to occupational post-application workers. All 

MOE values are calculated using the following formula:

where:

MOE = margin of exposure: value used by HED to represent risk estimates (unitless),

POD = point of departure (mg/kg/day), and

ADD = average daily dose absorbed in a given scenario (mg ai/kg/day).