### Page 3 of 16

1.0 Executive Summary

Azoxystrobin is a broad spectrum fungicide that controls plant diseases on agricultural crops, turf and ornamentals, and controls molds and fungi on indoor surfaces. The following formulated liquid end use products (EPs) are evaluated in this assessment: (1) Abound Flowable Fungicide (22.9% ai) , EPA Reg. No. 100

- 1098; (2) Quilt Fungicide, (7% azoxystrobin, 11.7% propiconazole), EPA Reg. No. 100

- 1178; and (3) Quilt Xcel Fungicide (13.5% azoxystrobin, 11.7% propioconazole) ; EPA Reg. No. 100

- 1 324

.

In this document, the name azoxystrobin will be used for the active ingre dient (ai) in these products

. O ccupational and residential exposure and risk estimates of propiconazole will be assessed in a separate document.

Proposed Use Profile :

Azoxystrobin is proposed for use a s a foliar application on cereal grain crops using ground, aerial and chemigation equipment. The use profile is summarized in Table 4.2 . Proposed single application rates on all proposed crops range from 0. 03 0

- 0.20 lb ai/A

.

Hazard Concerns:

In a 21

- d ay repeated dose dermal study in the rat, no dermal or systemic toxicity was seen at the limit dose (1,000 mg/kg/day). Furthermore, there was no concern for developmental or reproductive effects. Therefore, no hazard was identified for short

- and interme diate

- term dermal exposure scenarios, and a dermal risk assessment is not applicable at this time. The point of departure ( POD ) chosen for short

- term inhalation risk assessment is based on a developmental toxicity study in rats in which maternal effects ( increased diarrhea, urinary incontinence and salivation) were observed at the lowest observed adverse effect level (LOAEL) of 100 mg/kg/day. An oral no observed adverse effect level (NOAEL) of 25 mg/kg/day was identified
as the POD for the short

- term inha lation risk assessment. The POD chosen for intermediate

- term inhalation risk assessment is based on a 90

- day rat feeding study in which decreased body weight gain and clinical signs indicative of reduced nutrition were seen at the LOAELs of 211 (males)

an d 223 (females) mg/kg/day. An oral NOAEL of 20 mg/kg/day was identified as the POD for
the intermediate

- term inhalation risk assessment. Since the selected toxicological POD s are not based on developmental effects, the average adult body weight of 8 0 kg was used for estimating
short

- and intermediate

- term inhalation doses. Since no inhalation absorption data are available, toxicity by the inhalation route is considered to be equivalent to the toxicity by the oral route of exposure. Azoxystrobin is chara cterized as "not likely" to be a human carcinogen.

Residential Exposure:

There are no proposed residential uses at this time; however, there are existing residential uses that have been previously reassessed to reflect updates to HED’s 2012 Residential SOPs 1 

### along with policy changes for body weight assumptions (DP394287, K. Rury, 03/30/2012). All
residential risk estimates resulted in MOEs > 100 and

, therefor e, are not of concern to HED.

1 Available: http://www.epa.gov/pesticides/science/residential

- exposure

- sop.html

### Page 4 of 16

Based on the Agency's current practices, a quantitative non

- can cer occupational post

- application inhalation exposure assessment was not performed for azoxystrobin 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 azoxystrobin

.

Occupational Exposure:

Based on the proposed use pattern of azoxystrobin, t here is a potential for short

- and
intermediate

- term occupational exposure during handling (mixing

, loading , and applying ) and
post

- application activities. Chronic exposure is not expected for the proposed use patterns.

Occupational Handlers: The results of the occupational handler exposure and risk assessment estimates indicate that
short

- and intermediate

- term inhala tion MOEs are not of concern to HED ( i.e. MOE s > 100) with
baseline mitigation (no respirator) . The short

- term inhalation MOE s range from 38,000 to
570 ,000 for occupational handlers . The intermediate

- term MOEs range from 30,000 to 460 ,000 for occupationa l handlers

.

Agricultural Post

-

A pplication: Although occupational dermal exposure is expected following treatment of cereal grain crops

, dermal hazard was not identified for azoxystrobin. Therefore, a quantitative post

- application
dermal risk assessment was not conducted.

Based on the Agency's current practices, a quantitative non

- cancer occupational post

- application inhalation exposure assessment was not performed for azoxystrobin at this time. If new policies or procedures are put into pla ce, the Agency may revisit the need for a quantitative occupational
post

- application inhalation exposure assessment for azoxystrobin

.

A chemical

- specific dislodgeable foliar residue (DFR) study is available for the use of azoxystrobin on grapes, but has n ot been employed in this or previous risk assessments because
HED determined there is no hazard via the dermal route.

Restricted Entry Interval (REI): The REI specified on the proposed label is based on the acute toxicity of azoxystrobin. Based on
the Worker Protection Standard (WPS), a 12

- hour restricted entry interval (REI) is required for chemicals classified under Toxicity Category III or IV. Since a zoxystrobin is classified as Toxicity Category III for acute dermal and primary eye irritation and T oxicity Category IV for primary skin irritation, the 12

- hour REI listed on the two mixed active ingredient ( MAI ) label s (Quilt Fungicide and Quilt Xcel Fungicide) is appropriate.

For the Abound label, HED previously determined that the REI could be reduce d to 4 hours. Although a 12

- hour REI is the shortest waiting period permitted under the WPS, REIs may be
further reduced from 12 hours if certain criteria are met for both the technical material and the
different end

- use products in accordance with the Pe sticide Registration (PR) No tice 95

- 3 [Reduction of Worker P rotection Standard (WPS) Interim Restricted Entry Intervals (REIs) for

### Page 5 of 16

Certain Low Risk Pesticides]. 2 

### Since these criteria have been met for both the technical and the EP, the 4

- hour REI listed on the Abound label is appropriate.

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 and the AHETF database, are (1) subject to ethics review pursuant to 40 CFR 26, (2) have received that review, and (3) are compliant with applicable ethics requireme nts. 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
website 3



### .

2.0 Summary of Conclusions and Data Requirements

There are no occupational/residential risk estimates of concern associated with the proposed new
uses of azoxystrobin

.

Residue Data Requirements Turf Transferable Residue (TTR): In accordance with the updated Part 158 data requirements (2007), a TTR study is required for all occupational (e.g., sod farms, golf courses, parks, and recreational areas) or residential turf uses. However, a TTR study is not required for azoxystrobin a t this time because dermal and systemic toxicity were not seen in a 21

- day repeated dose dermal study in the rat up to the limit dose (1,000 mg/kg/day). Additionally, all
incidental oral risk estimate s from azoxystrobin use on turf result in MOEs ≥ 1,800 (with an LOC of 100)

.

3 .0 Hazard Characterization

The toxicological doses and endpoints supporting this petition remain unchanged and have been summarized in the previous human health risk assessment (DP394285, K. Rury, 04/30/2012).

Acute Toxicity

Tabl e 3 .1

. Acute Toxicity Data on Technical Azoxystrobin.

Guideline
No. Study Type MRID # Results Toxicity Category

870.1100 Acute Oral

- Rat 43678122 LD 50 > 5000 mg/kg (Limit Test) in Males & Females IV

870.1200 Acute Dermal

- Rat 43678124 LD 50 > 2000 mg/kg (Limit Test) in Males & Females III

870.1300 Acute Inhalation

-

Rat 43678126 LC 50 Males = 0.962 mg/L (95% C.I. = 0.674) Females = 0.698 mg/L (95% C.I. = 0.509, 2.425)
The combined LC50 was not calculated due to mortality pattern III

870.2400 Primary Eye

Irritation

- Rabbit 43678128 Slight to moderate erythema and slight chemosis in all rabbits within one hour, but effects resolved within 48

hours of treatment. III

2 Available: http://www.epa.gov/PR_Notices/pr95

- 3.html

3 http://www.epa.gov/pesticides/science/handler

- exposure

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

- app

- exposure

- data.html

### Page 6 of 16

Table 3.1

. Acute Toxicity Data on Technical Azoxystrobin.

Guideline
No. Study Type MRID # Results Toxicity Category

870.2500 Primary Skin

Irritation

- Rabbit 43678130 Very slight erythema and edema that persisted for three days on one rabbit and for one hour on another. IV

870.2600 Dermal Sensitization

- Guinea Pig 43678132 No erythema or edema were found 38 or 48 hrs after challenge with test material. Not a dermal
sensitizer



### Toxicological POD s Used for Risk Assessment

Table 3. 2

. Summary of Toxicological Doses and Endpoints for Azoxy strobin for Use in Dietary, Non

Occupational and Occupational Human Health Risk Assessments. 1

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) NOAEL = 25

mg/kg/day UF A = 10X

UF H = 10X FQPA SF = 1X Residential

LOC for MOE
= 100 Prenatal Developmental Oral Toxicity

– Rat.

LOAEL = 100 mg/kg/day based on increased maternal diarrhea, urinary incontinence, and
salivation.
Incidental Oral
Intermediate

Term (1

- 6 months) NOAEL = 20

mg/kg/day UF A = 10X

UF H = 10X FQPA SF = 1X Residential

LOC for MOE
= 100 90

- day Feeding Study

– Rat. LOAEL = 211/223

mg/kg/day (M/F) based on decreased body weight gain in both sexes and clinical signs
indicativ e of reduced nutrition.

Dermal (All Durations) No hazard was identified for this exposure scenario. 21

- Day Repeated Dose Dermal Study

– Rat. No dermal or systemic toxicity was seen at the limit dose (1,000 mg/kg/day).

Inhalation Short

Term (1

- 30 days) Oral NOAEL
= 25 UF A = 10X

UF H = 10X FQPA SF = 1X Occupational &

Residential
LOC for MOE
= 100 Prenatal Developmental Oral Toxicity

– Rat.

LOAEL = 100 mg/kg/day based on increased maternal diarrhea, urinary incontinence, and
salivation.
Inhalation
Intermediate

Term (1

- 6 months) Oral NOAEL
= 20 UF A = 10X

UF H = 10X FQPA SF=1X Occupational &

Residential
LOC for MOE
= 100 90

- day Feeding Study

– Rat. LOAEL = 211/223

mg/kg/day (M/F) based on decreased body weight gain in both sexes and clinical signs
indicative of reduced nutrition.
Cancer (oral, dermal, inhalation) Azoxystrobin is classified as "Not Likely" to be carcinogenic to humans.

1 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. UF A = e xtrapolation from animal to human (interspecies). UF H = potential variation in sensitivity among members of the human population (intraspecies). FQPA SF = FQPA Safety Factor. PAD = population adjusted dose (a = acute, c = chronic). RfD = reference dose . MOE = margin of exposure. LOC = level of concern. N/A = not applicable.



### 4 .0 Use Profile

Syngenta has submitted proposed use directions (Section B) for the following liquid EPs: (1) Abound Flowable Fungicide, EPA Reg. No. 100

- 1098; (2) Quilt Fungicid e, EPA Reg. No. 100

- 1178; and (3) Quilt Xcel Fungicide; EPA Reg. No. 100

- 1 324

. Table 4.1 summarizes the registered EPs, while Table 4.2 presents the proposed use directions on each of the proposed cereal grains (barley, oats, rye, wheat, and triticale).

### Page 7 of 16

Table 4.1. Summary of Proposed Azoxystrobin End

- Use Products.

Trade Name Reg. No. % ai of formulation Formulation Type Target Crop Source

Abound
Flowable Fungicide 100

- 1098 22.9% azoxystrobin (2.08 lb ai/gal) S C

Cereals Grains (barley, oats, rye

, wheat, triticale ) Undated supplemental label

included in Section B of the petition. Quilt Fungicide 100

- 1178 7% azoxystrobin (0.62 lb ai/gal) 11.7% propiconazole (1.04 lb ai/gal) EC

Quilt Xcel Fungicide 100

- 1324 13.5% azoxystrobin (1.18 lb ai/gal)
11.7% propiconazole (1.02 lb ai/gal) E C

Table 4 .2 . Su mmary of Directions for Use of Azoxystrobin

.
Applic. Timing, Type, and Equip. Formulation

[EPA Reg. No.] Applic.

Rate ( fl
oz and lb ai/A) Max. No.

Applic. per
Season 1 Max. Seasonal

Applic. Rate ( fl oz and lb ai/A) PHI

(days) Use Directions and Limitations 2

Cereals (Wheat, Triticale)

Foliar: Ground,
Aerial or Chemigation 2.08 lb

ai/gal SC [100

- 1098] 4.0

- 12

(0.07

- 0.20) 2 24 ( 0.40 ) 7

forage and hay Applications are to be made prior to
disease development

. Minimum volume for air applications is 5 gal/A.
Foliar: Ground,
Aerial or Chemigation MAI

(0.62 lb ai/gal) [100

- 1178] 7

- 14

(0.03

- 0.07) 2 28 (0.14) 7

forage and hay Apply Quilt in the spring for suppression of early season diseases. Follow up with a second application for full season control. Protecting the flag leaf is important for maximizing yield. For high yields apply Quilt when flag leaf is 50% to full head emergence (Feekes 10.5). Foliar: Ground,
Aerial or Chemigation MAI

(1.18 lb ai/gal) [100

- 1324] 7

- 14

(0.06

- 0.13) 2 28 (0.26) 7

forage and hay

Cereals (Barley, Oat and Rye) 100

- 1178, 100

- 1324 includes Triticale

Foliar: Ground,
Aerial or Chemigation 2.08 lb

ai/gal SC [100

- 1098] 6

- 12

(0.10

- 0.20) 2 24 ( 0.40 ) 7

forage and hay Applications are to be made prior to disease development. Minimum volume for air applications is 5 gal/A.
Foliar: Ground,
Aerial or Chemigation MAI

(0.62 lb ai/gal) [100

- 1178] 7

- 14

(0.03

- 0.07) 2 28 (0.14) 7

forage and hay Apply Quilt in the spring for suppression of early season diseases. Follow up with a second application for full season control. Protecting the flag leaf is important for maximizing yield. For high yields apply Quilt when flag leaf is 50% to full head emergence (Feekes 10.5). Foliar: Ground,
Aerial or Chemigation MAI

(1.18 lb ai/gal) [100

- 1324] 7

- 14

(0.06

- 0.13) 2 28 (0.26) 7

forage and hay

1 For resistance management, no more than two sequential applications of Abound Flowable Fungicide or other Group 11 fungicides should be made before alternating with a fungicide having a different mode of action (not in Group 11). Do not make more than two foliar applications of Abound Flowable Fungicide or other Group 11 fungicide per season.
2 Applications may be made no closer than a 14

- day interval. Do not apply after Feekes 10.54. Do not apply more than 0.40 lb ai/A per season of azoxystrobin

- containing products.



### The azoxystrobin product labels direct mixers, loaders, applicators and other handlers to wear a long

- sleeved shirt, long pants, chemical

- resistant gloves made of any waterproof material (such as polyvinyl chloride, nitrile, rubber or butyl rubber), shoes plus socks, and protective eyewear.

### Page 8 of 16

5 .0 Residential Exposure and Risk Estimates

There are no proposed residential uses at this time; however, there are existing residential uses
that have been previously reassessed to reflect updates to HED’s 2012 Residential SOPs 4 

### along with policy changes for body weight assumptions (DP394287, K. Rury, 03/30/2012)

.

5 .1 Residential Handler Exposure/Risk Estimates

HED uses the term “handlers” to describe those individuals who are involved in the pesticide applicat ion process. HED believes that there are distinct tasks related to applications and that exposures can vary depending on the specifics of each task as was described above for occupational handlers. Residential handlers are addressed somewhat differently by HED as homeowners are assumed to complete all elements of an application without use of any protective equipment.

Summary of Residential Handler Non

- Cancer Exposure and Risk Estimates The MOEs for adult handlers ranged from 2,400 (painting with an airless sprayer) to 1,000,000,000 (M/L/A a wettable powder to gardens and trees using a hose

- end sprayer).

Table 5 .1

. Short

- Term Residential Handler Non

- C ancer Exposure and Risk Estimate for Azoxystrobin

.

Exposure Scenario Level of
Concern Inhalation Unit Exposure (μ g/lb ai) Maximum

Application
Rate 1 Area Treated or

Amount Handled Daily 2 Inhalation

Dose (mg/kg/day) 3 MOE 4

Applicator

Painting with Airless Sprayer 100 0.56 1.0% ai by weight 5 one

- gallon cans 0.0149 2,400

Painting with a Brush 100 0.2 1.0% ai by weight 2 one

- gallon

cans 0.0005 50,000

Indoor Manually

- Pressurized
Handwand Wettable Powder 100 1.1 0.0047 (lb ai/gal) 0.5 gallons 0.000032 770,000

Indoor Manually

- Pressurized
Handwand Wettable Powder in

WSB 100 1.1 0.0047 (lb ai/gal) 0.5 gallons 0.000032 770,000

M/L/A Wettable Powders to Turf [Hose End Sprayer] 100 0.022 0.95 (lb ai/A) 0.5 acres 0.00013 190,000

M/L/A Wettable Powder to Turf [Manually Pressurized Handwand or Backpack Sprayer] 100 1.1 0.011 (lb ai/gal) 5 gallons 0.00076 33,000

M/L/A Wettable Powders in WSB to Turf [Hose End Sprayer] 100 0.034 0.95 (lb ai/A) 0.5 acres 0.0002 120,000

M/L/A Wettable Powder in WSB to Turf [Manually Pressurized Handwand or Backpack Sprayer] 100 0.018 0.011 (lb ai/gal) 5 gallons 0.000012 2,000,000

M/L/A Wettable Powder Azoxystrobin to Gardens and Trees [Manually

- Pressurized Handwand or Backpack Sprayer] 100 1.1 0.000125 (lb ai/gal) 5 gallons 0.0000086 2,900,000

4 Available: http://www.epa.gov/pesti cides/science/residential

- exposure

- sop.html

### Page 9 of 16

Table 5 .1

. Short

- Term Residential Handler Non

- C ancer Exposure and Risk Estimate for Azoxystrobin

.

Exposure Scenario Level of
Concern Inhalation Unit Exposure (μ g/lb ai) Maximum

Application
Rate 1 Area Treated or

Amount Handled Daily 2 Inhalation

Dose (mg/kg/day) 3 MOE 4

M/L/A Wettable Powder Azoxystrobin to Gardens and Trees [Hose

- End Sprayer] 100 0.0014 0.000125 (lb ai/gal) 11 gallons 0.000000024 1,000,000,000

M/L/A Wettable Powder Water Soluble Packets Azoxystrobin to Gardens and Trees [Manually

Pressurized Handwand or Backpack Sprayer] 100 0.018 0.000125 (lb ai/gal) 5 gallons 0.00000014 180,000,000

M/L/A Wettable Powder Water Soluble Packets Azoxystrobin to Gardens and Trees [Hose

- End

Sprayer] 100 0.034 0.000125 (lb ai/gal) 11 gallons 0.00000059 43,000,000

1 Based on register ed or proposed label (Reg. No. 100

- 1229 ).
2 Exposure Science Advisory Council Policy #9.1.
3 Inhalation Do se = Inhalation Unit Exposure (μ g/lb ai) x Conversion Factor (0.001 mg/μ g) x Application Rate (lb ai/acre or gal) x Amount Handled ( gallons/day) / BW (kg).
4 Inhalation MOE = Inhalation NOAEL (mg/kg/day) / Inhalation Dose (mg/kg/day). Short

- term Inhalation NOAEL = 25 mg/kg/day.



### 5

. 2 Residential Post

- A pplication 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 azoxystrobin

. Residential exposure is expected to be short

- term in duration.

Summary of Residential Post

- A pplication Non

- Cancer Exposure and Risk Estimates Although residential dermal exposure is expected following treatment of turf, no dermal hazard was identified for azoxystrobin. Therefore, a quantitative post

- application dermal risk assessment was not conducted. The exposure and risk estimates for all r esidential post

application uses result in risk estimates that are greater than the LOC MOE of 100, and therefore
are not of concern to HED. The MOEs ranged from 250 to 810,000 for incidental oral ingestion of azoxystrobin in indoor and outdoor environme nts . The highest residential non

- cancer
exposure s and risk estimate s resulted from indoor post

- application inhalation exposure from broadcast carpet use ( MOE s were 220,000,000 ,000 for adults and 52,000,000,000 for children)

.

Table 5

. 2

. Highest Residenti al Post

- A pplication Non

- C ancer Exposure and Risk Estimates for Azoxystrobin.

Lifestage Post

- A pplication Exposure Scenario Dose (mg/kg/day) MOEs

Adult Indoor Carpet

- Broadcast Inhalation 0.00000000011 220,000,000,000

Child Inhalation 0.00000000087 52,000,000,000

Hand to Mouth 0.098 250



### 5 .3 Combined Residential Risk Estimates (Multiple Exposure Scenarios)

Residential handler and post

- application scenarios do not need to be combined. Although there is potential for the same individual (i.e. an adult) to apply a pesticide in and around the home and be exposed by reentering a treated area in the same day, it is inappropriate to c ombin e both of these exposure scenarios because of the conservative nature of each individual assessment.

### Page 10 of 16

5

. 4 Residen tial Risk Estimates for Use in Aggregate Assessment

Table 5.4 reflects the high

- end residential risk estimates that are recommended for use i n the aggregate assessment for azoxystrobin

. The recommended residential exposure for use in the adult aggregate assessment reflects inhalation exposure from handlers applying paint via airless sprayers. The recommended residential exposure for use in the children 1 to <2 years old aggregate

assessme nt reflects inhalation and hand

- to

- mouth exposures from post

- application exposure to indoor applications to carpets.

Table 5

. 4

. Recommendations for the Residential Exposures for the Azoxystrobin Aggregate Assessment

. 1

Lifestage Handler Exposure

(mg/kg/day) 2 Residential

Handler Total
MOE 3 Post

- Application Exposure

(mg/kg/day) Residential Post

Application Total Exposure (mg/kg/day) 4 Residential Post

Application
MOE 5 Inhalation Inhalation Oral

Short

- Term
Adult 0.0149 2,400 N/A N/A N/A N/A

Child N/A N/A 0.00000000087 0.0982 0.0982 250

1 N/A = not applicable. Adult post

- application exposures do not need to be aggreg ated with the handler exposures, and children handler exposures are not expected. F or adults, the r esidential total exposure is equivalent to the inhalation exposure (Table 5.1). For young children, total residential exposure combines high

- end inhalation and post

- application incidental oral exposure (Table 5.2).
2 Handler exposure repre sents high

- end handler exposure ( i.e. the hi ghest handler exposure of all scenarios assessed)

. 3 Total MOE = Inhalation MOE = NOAEL / Inhalation Exposure

. Short

- Term I nhalation NOAEL = 25 mg/kg/day

. 4 Post

- application exposure represents high

- end inhalation and/or incidental oral exposure for the r elevant exposure duration

. 5 Total MOE = NOAEL ÷ ( Inhalation Exposure + Incidental O ral Exposure ). Inhalation NOAEL = Incidental O ral NOAEL =
25 mg/kg/day.



### 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 metho d employed for azoxystrobin

. 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 information 5



### . On a chemical by chemical basis, the Agency is now requiring interim mitigation measures for aerial applications that must be placed on product labels/labeling. The Agency has completed its
evaluation of the new data base 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 airbla st

, 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

5 Available: http://www.epa.gov/opp00001/factsheets/spraydrift.htm

### Page 11 of 16

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 Ex posure

Based on the Agency's current practices, a quantitative post

- application inhalation exposure assessment was not performed for azoxystrobin at this time primarily because of the low acute inhalation toxicity (Toxicity Category III), low vapor pressu re ( 8.2x10 - 13 

### mm Hg at 20oC ), and the low proposed use rate (0. 20 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 in put 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, 2010 6



### . The Agency is in the process of

eva luating 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 d eveloped, the Agency may revisit the need for a quantitative post

- application inh alation exposure assessment for azoxystrobin

.

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 t ask. 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 occupat ional handlers is based on the following scenarios: Mixing/loading liquids for groundboom

, aerial

, and chemigation application, Applying liquids via groundboom and aircraft , and Flagging for aerial application.

Occupational Handler Exposure Data and Assu mptions 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 : See Section 4.0.

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

### Page 12 of 16

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 and the AHETF database . Some of these data are proprieta ry 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 Exposur e Surrogate Reference Table 7 

### ”, 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 website 8



### .

Estimates of dermal and inhalation exposure were calculated for various levels of personal protective equipment (PPE). Results are presented for “baseline,” defined as a single layer of clothing consisting of a long sleeved shirt, long pants, shoes plus s ocks, no prote ctive gloves, and no respirator. However, t he azoxystrobin product labels direct mixers, loaders, applicators and
other handlers to wear a long

- sleeved shirt, long pants, chemical

- resistant gloves made of any waterproof material (such as pol yvinyl chloride, nitrile, rubber or butyl rubber), shoes plus socks, and protective eyewear

.

Area Treated or Amount Handled : Based on HED ExpoSAC Policy 9.1, the amount treated or handled per day was assumed to be: 80 acres for mixing/loading for groundboom applications and applying via ground equipment on barley, oats, and rye, 350 acres for mixing/loading for aerial applications and applying via aircraft on barley, oats, and rye

, 200 acres for mixing/loading groundboom applications and apply ing via ground equipment on wheat and triticale,

1200 acres for mixing/loading for aerial applications and applying via aircraft on wheat and triticale, and

350 acres for f

lagging for aerial application on all cereal grain crops.

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.

Absorption F

actors: Since inhalation absorption d ata are not available, toxicity by the inhalation route is considered to be equivalent to the estimated toxicity by the oral route of exposure.

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

7 Available: http://www.epa.gov/opp0000 1/science/handler

- exposure

- table.pdf

8 Available: http://www.epa.gov/pesticides/science/handler

- exposure

- data.html

### Page 13 of 16

occupational handlers will not apply the same chemical every day for more than a one

- month time frame; however, there may be a la rge agribusiness and/or commercial applicators who may apply a produ ct over a period of weeks (e.g. completing multiple applications for mult iple clients within a region).

Based on the proposed uses f or azoxystrobin

, short

- and intermediate

- term exposure s are expected for the following reas ons: (1) two applications can be made per season with a minimum retreatment interval (RTI) of 14 days; and (2) azoxystrobin is a broad spectru m fungicide which may be used for both early season suppression and full seas on control

.

Mitigation/Personal Protective Equipment: Occupational handler exposure assessments are completed by HED using different levels of risk mitigation. Typically, HED uses a tiered approach. The lowest tier is designed as the baseline exposure scenario ( i.e. long

- sleeve shirt, long pants, shoes, socks, no respirator). If risk estimates are of concern at baseline attire, then increasing levels of PPE ( i.e. gloves, respirators) are evaluated. If risk estimates remain a concern with maximum PPE, then engineering controls ( i.e. enclosed cabs or cockpits, water

soluble packaging, and closed mixing/loading systems) are evaluated. This approach is used to ensure that the lowest level of risk mitigation that provides adequate protection is selected, s ince the addition of PPE and engineering controls involves an additional expense to the user and (in the case of PPE) also involves an additional burden to the user due to decreased comfort and dexterity and increased heat stress and respiratory stress.

O ccupational Handler Non

- Cancer Exposure and Risk Estimate Equations Potential daily exposures for occupational handlers were calculated using the following formula: Daily Exposure (mg ai /day) = UE ( μ g ai / lb ai) × AR (lb ai /A) × AT (A /day) × 1E

- 3 mg/μg

w here: Daily Exposure = Amount (mg ai/day) that is available for inhalation absorption,
UE = Unit Exposure ( μ g ai / lb ai)

, AR = maximum application rate according to proposed label (lb ai /A) , and
AT = daily acres treated (A /day)

.



### The daily doses were calculated using the following formula: Average Daily Dose (mg ai/kg/day) = [Daily Expo sure (mg ai/day) × Absorption ( %)] Body Weight (kg)

w here: Average Daily Dose = Absorbed dose received from exposure to a pesticide in a given scenari o (mg pesticide active ingredient/kg body weight/day), Daily Exposure = Amount (mg ai/day) that is available for inhalation absorption, Absorption Factor = A measure of the amount of chemical that crosses a biological boundary such as the lungs (%) , and Body Weight = Body weight determined to represent the population of interest in a risk assessment (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 inhalation dose received by occupational handlers were compared to the appropriate POD ( i.e. NOAEL) to assess the risk to occupational handlers for each exposure route. All MOE values were calculated using the following formula:

MOE = POD (t

ypically a NOAEL in mg/kg/day) ADD (mg/kg/day)

w here:

### Page 14 of 16

MOE = Margin of Exposure: value used by HED to represent risk or risk estimates (unitless)

, POD = Point of Departure

, NOAEL = No Observed Adverse Effect Level (mg/kg/day) : Dose level in a toxicity study

, where no observed

adverse effects occurred in the study, and
ADD = Average Daily Dose (mg/kg/day) : the absorbed dose received from exposure to a pesticide in a given

scenario

.



### Summary of Occupational Handler Non

- Cancer Exposure and Risk Estimates
The short

- term occupational handler inhalation exposure risk estimates are not of concern to HED with baseline mitigation (Table 6.1). With baseline mitigation (no respirator) , the inhalation MOEs for occupational handlers of azoxystrobin to cereal grain crops range from 38,000 to 570,000. The intermediate

- term occupational handler inhalation exposure risk estimates are not of concern to HED with baseline mitigation (Table 6.1 ). With baseline mitigation (no respirator) , the inhalation MOEs for occupational handlers of azoxystrobin to cereal grain crops range from 30,000 to 460,000.

The Agency has evaluated scenarios that may be limited in nature such as flagging during aeri al applications because engineering controls ( i.e. Global Positioning Satellite technology) are now predominantly used as indicated by the 1998 National Agricultural Aviation Association (NAAA) survey of their membership. It appears, however, flaggers are still used in approximately 10 to 15 percent of aerial application operations. In cases like these, the Agency strongly encourages the use of the engineering control system but will continue to evaluate risks for flaggers and any other population where a clear exposure pathway exists until the potential for exposure is eliminated. The Agency is aware that NAAA is conducting another survey on exposure issues and will consider those results as are timely and appropriate.

HED has no data to assess exposure s 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); pilots are not required to wear protective gloves. With this level of protection, there

are no risk estimates of concern for applicators.

Table 6.1. Short

- and Intermediate

- Term Occupational Exposure and Risk Estimates for Proposed Use of
Az oxystrobin on Cereal Grains (Barley, Oats, Rye, Wheat, and Triticale)

. All estimates are at baseline mitigation (single layer without gloves or respirator y protection ).

Exposure Scenario Crop(s) Baseline
Inhalation
Unit Exposure (μg/lb ai) 1 Maximum

Application Rate (lb ai/A) 2 Area

Treated or
Amount
Handled Daily 3 Inhalation

Dose (mg/kg/day) 4 Short

- Term

MOE 5 Intermediate

Term MOE 6

Mixer/Loader

Mixing/Loading Liquids for Groundboom Application Barley, Oats, Rye

0.219 0.20 80 0.000044 570,000 460,000

Wheat,
Triticale 200 0.00011 230,000 180,000

Mixing/Loading Liquids for Aerial and Chemigation Application Barley, Oats, Rye 350 0.00019 130,000 100,000

Wheat,
Triticale 1200 0.00066 38,000 30,000

### Page 15 of 16

Table 6.1. Short

- and Intermediate

- Term Occupational Exposure and Risk Estimates for Proposed Use of Azoxystrobin on Cereal Grains (Barley, Oats, Rye, Wheat, and Triticale)

. All estimates are at baseline mitigation (single layer without gloves or respirator y protection ).

Exposure Scenario Crop(s) Baseline
Inhalation
Unit Exposure (μg/lb ai) 1 Maximum

Application Rate (lb ai/A) 2 Area

Treated or
Amount
Handled Daily 3 Inhalation

Dose (mg/kg/day) 4 Short

- Term

MOE 5 Intermediate

Term MOE 6

Flagger

Flagging for Aerial Application Barley, Oats, Rye, Wheat,
Triticale 0.35 0.20 350 0.00031 82,000 65,000

Applicator

Applying Sprays via Groundboom Equipment Barley, Oats, Rye 0.34

0.20 80 0.000068 370,000 290,000

Wheat,
Triticale 200 0.00017 150,000 120,000

Applying Sprays via Aerial Equipment * Barley, Oats, Rye 0.068 350 0.000060 420,000 340,000

Wheat,
Triticale 1200 0.00020 120,000 98,000

1 Based on “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (March 2012 ); includes data from PHED /AHETF

. Level of mitigation: Baseline

. 2 Based on registered labels with proposed new uses (Reg. No s . 100

- 1098, 100

- 1178, 100

- 1324).
3 Exposure Science Advisory Council Policy #9.1.
4 Inhalation Dose = Inhalation Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre) × Area Treated Daily (A/day) ÷ BW (kg). Bodyweight = 80 kg.
5 Inhalation MOE = Inhalation NOAEL (mg/kg/day) ÷ Inhalation Dose (mg/kg/day). Short

- Term Inhalation NOAEL = 25 mg/kg/day.

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

- Term Inhalation NOAEL = 20 mg/kg/day.



### 6

. 2 Occupational Post

- A pplication 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 re

entry exposure). Such exposures may occur when workers enter previously treated areas to perform job functions, including activities related to crop production, s uch as scouting for pests or harvesting. Post

- application exposure levels vary over time and depend o n 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 degradatio n 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

- A pplication Dermal Exposure/Risk Estimates

The proposed occupational uses for azoxystrobin addressed in this document result in the potential for exposure to azoxystrobin during scouting, hand weeding, and hand harvesting. However, no appropriate dermal endpoint was identified for azoxystrobin. T herefore, an assessment of occupational dermal post

- application exposure to azoxystrobin was not conducted.
A c hemical

- specific dislodgeable foliar residue (DFR) stud y is available for the use of azoxystrobin on grapes, but has not been employed in this o r previous risk assessments because
HED determined there is no hazard via the dermal route.

### Page 16 of 16

Restricted Entry Interval

The REI specified on the proposed label is based on the acute toxicity of azoxystrobin. Based on the Worker Protection Standard (WP S), a 12

- hour restricted entry interval (REI) is required for chemicals classified under Toxicity Category III or IV. Since a zoxystrobin is classified as Toxicity Category III for acute dermal and primary eye irritation and Toxicity Category IV for primar y skin irritation, the 12

- hour REI listed on the two MAI label s (Quilt Fungicide and Quilt Xcel Fungicide) is appropriate.

For the Abound label, HED previously determined that the REI could be reduced to 4 hours. Although a 12

- hour REI is the shortest waiting period permitted under the WPS, REIs may be
further reduced from 12 hours if certain criteria are met for both the technical material and the
different end

- use products in accordance with the Pesticide Registration (P R) Notice 95

- 3 [Red uction of Worker P rotection Standard (WPS) Interim Restricted Entry Intervals (REIs) for Certain Low Risk Pesticides]. 9 

### Since these criteria have been met for both the technical and the EP, the 4

- hour REI listed on the Abound label is a ppropriate.

6.2.1 Occupational Post

- A pplication Inhalation Exposure/Risk Estimates

Based on the Agency's current practices, a quantitative post

- application inhalation exposure

a ssessment was not performed for azoxystrobin at this time primarily because of the low acute inhalation toxicity (Toxicity Category III), low vapor pressure ( 8.2x10 - 13 

### mm Hg at 20oC ), and the low proposed use rate (0. 20 lb ai/A). However, there are multiple potential sources of post

application inh alation 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 exp ert 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, 2010 10



### . The Agency is in th e 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 occupat ional 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 inh alation exposure assessment for azoxystrob in

.

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 ou tdoors 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.

9 Available: http://www.epa.gov/PR_Notices/pr95

- 3.html

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