Date: 

Subject: 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

24-JAN-2014 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

Flutriafol. Occupational and Residential Exposure Assessment for Proposed 

Uses on Cucurbit Vegetables, Fruiting Vegetables, Strawberries, Tree Nuts, 

Wheat/Triticale, Brassica (cole) Leafy Vegetables, Celery, Leafy Vegetables, 

Cotton, Sorghum 

PC Code: 128940 DP Barcode: 0416213, 0416214, 0416216 

Registration No.: 67760-75, 67760-REN 

Regulatory Action: Section 3 

Decision No.: 475694, 478287, 482872 

Petition No.: N/A 

Risl< Assessment Type: Occupational/Residential 

Exposure Assessment 

Case No.: 7060 

TXR No.: NA 

MRID No.: 47090415 

CAS No.: 76674-21-0 

40 CFR: § 180.629 

From: 

Through: 

To: 

Introduction 

Kelly M. Lowe, Environmental Scientist~~ Risk Assessment Branch 1 (RAB 1) ~ ~ - bu · 

Health Effects Division (7509P) 

Charles 

Health Effects 

W. Smith, 

Division 

Branch 

(7509P Chief~ 

~ ~ 

and 

Shalu Shelat, Reviewer ~~· · 

Ivan Nieves, Reviewer ..-r .-- ___. Exposure Science Advisory Co mittee (ExpoSAC) I HED 

Tamue Gibson, RM21 

Fungicide Branch 

Registration Division (7505P) 

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

exposure and risk assessment for three actions related to flutriafol: 

( 1) new uses on cucurbit vegetables, fruiting vegetables, strawberries, tree nuts, and 

wheat/triticale (D416216); 

(2) new uses on Brassica (cole) leafy vegetables, celery, leafy vegetables, cotton, and 

Page 1 of23 
sorghum (D416213); and 

(3) an amendment to the tolerances for field corn and popcorn (D416214). 

A quantitative assessment of occupational exposure has been conducted for all of the proposed 

uses of flutriafol (D416216 and D416213); however, it was determined that an exposure 

assessment was not necessary for the corn tolerance amendment (D416214) since corn is a 

registered use site and has been assessed previously. The proposed tolerance changes do not 

impact the use pattern or application rate for the registered use on com, and, therefore, a revised 

exposure assessment is not required. The previous assessment (Memo, K. Lowe, 9/20111, 

D383037) provides the exposure and risk estimates for this use. 

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; and the Agricultural Reentry Task Force (ARTF) database. 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 Committee 

(ExpoSAC) on 12-DEC-2013. 

.Page 2 of23 
Page 3 of 23

Table of Contents

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

2.0 Risk Assessment Conclusions and Recommendations........................................................ 5

2.1 Summary of Risk Estimates............................................................................................. 5

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

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

3.0 Hazard Characterization....................................................................................................... 6

4.0 Exposure and Use Profile..................................................................................................... 8

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

5.1 Spray Drift...................................................................................................................... 10

5.2 Residential Bystander Post-Application Inhalation Exposure ....................................... 10

6.0 Occupational Exposure and Risk Estimates ...................................................................... 11

6.1 Occupational Handler Exposure/Risk Estimates............................................................ 11

6.2 Occupational Post-application Exposure/Risk Estimates .............................................. 17

6.2.1 Occupational Post-application Inhalation Exposure/Risk Estimates...................... 17

6.2.2 Occupational Post-application Dermal Exposure/Risk Estimates.......................... 18

Appendix A. Summary of Occupational Non-cancer Algorithms............................................... 21
Page 4 of 23

1.0 Executive Summary

Flutriafol [(±)-α-(2-fluorophenyl)-α-(4-fluorophenyl)-1H-1,2,4-triazole-1-ethanol] is a systemic, 

triazole fungicide that can be used as a systemic eradicant and a protectant. It has a postinfection activity that can stop pathogen establishment in the early phases of disease 

development. It is currently registered for use on a variety of agricultural crops, including corn, 

grapes, soybeans, apples, peanuts, pome fruit, stone fruit, and sugarbeets. Cheminova is 

requesting three actions related to flutriafol: (1) new uses on cucurbit vegetables, fruiting 

vegetables, strawberries, tree nuts, and wheat/triticale (D416216); (2) new uses on Brassica 

(cole) leafy vegetables, celery, leafy vegetables, cotton, and sorghum (D416213); and (3) an 

amendment to the tolerances for field corn and popcorn (D416214).

Exposure and Proposed Use Profile

The proposed uses involve three labels: Flutriafol® 250 g/L (EPA Reg. #: 67760-REN), 

TopGuard® Fungicide (EPA Reg. #: 67760-75), and Flutriafol® 500 g/L (EPA Reg. #: 67760-

REA). The proposed new uses are on cucurbit vegetables, fruiting vegetables, strawberries, tree 

nuts, wheat/triticale, Brassica (cole) leafy vegetables, celery, leafy vegetables, cotton, and 

sorghum. All of the uses are proposed at a maximum application rate of 0.114 lb ai/A, to be 

made to the foliage via aerial, groundboom or airblast applications. None of the uses allow for 

application via chemigation. There is one proposed soil-directed application of flutriafol for 

cotton at a rate of 0.26 lb ai/A (one application per season). The foliar applications are allowed 

for up to four times per season, with a retreatment interval of 7 days. The restricted entry 

interval for all the proposed uses is 12 hours. Based on the proposed use pattern, it has been 

determined that the potential exposure scenarios that will need to be assessed include short- and 

intermediate-term occupational exposures (handler and post-application). 

Hazard Profile

The short- (1-30 days), and intermediate- (1-6 months) term dermal and inhalation toxicological 

points of departure were identified from a prenatal developmental toxicity study in the rabbit 

where the effects were based on decreased number of live fetuses, complete litter resorptions and 

increased post-implantation loss. The NOAEL was 7.5 mg/kg/day. Flutriafol was classified as a 

“not likely” human carcinogen based on the carcinogenicity studies in rats and mice. The total 

uncertainty factor (UF) that was applied to occupational and residential risk assessments is 100 

for short- and intermediate-term risks (10x interspecies factor, 10x intraspecies factor). Since the 

POD for the dermal and inhalation routes of exposure are based on the same effect, the 

exposures from these routes can be combined to estimate total risk.

Residential Exposure and Risk

There are no residential uses proposed or currently registered for flutriafol. Therefore, 

residential handler and post-application exposure/risk were not assessed. 

Occupational Exposure and Risk

The occupational handler exposure and risk estimates indicate that the short- and intermediateterm dermal and inhalation combined MOEs are not of concern to HED (i.e., MOE > 100) with 

the use of chemical-resistant gloves as directed by the label. At the baseline level of personal 

protection (i.e., no gloves and no respirator), only one scenario results in a risk estimate below 
Page 5 of 23

the LOC with a combined (dermal + inhalation) MOE of 82; this scenario is mixing/loading a 

liquid formulation for aerial application to high acreage crops. With the addition of gloves, the 

combined dermal + inhalation MOE is 470, which is not of concern. All other scenarios result in 

risk estimates greater than 220 with baseline attire.

The occupational post-application dermal exposure and risk estimates are greater than the LOC 

of 100 on the day of application, ranging from 230 to 4,600 depending on crop and activity. 

Since the post-application assessment is not a concern on Day 0 (12 hours following 

application), the restricted entry interval (REI) is based on the acute toxicity of flutriafol

technical material. Flutriafol has low acute toxicity via the oral, dermal and inhalation routes 

(Toxicity Categories III and IV), is minimally irritating to the eyes (Toxicity Category III), and is 

not a dermal irritant (Toxicity Category IV). Flutriafol was not shown to be a skin sensitizer 

when tested in guinea pigs (Buehler method). Therefore, the acute toxicity categories for this 

chemical require a 12 hour REI under 40 CFR 156.208 (c) (2) (iii). The 12-hour REI, which 

currently appears on the labels, is adequate for the proposed uses.

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

inhalation exposure assessment was not performed for flutriafol 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 flutriafol.

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 

the PHED 1.1, the AHETF database, and the ARTF database are (1) subject to 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

There are no occupational risk estimates of concern for the proposed uses for flutriafol. At the 

baseline level of personal protection (i.e., no gloves and no respirator), only one scenario results 

in a risk estimate below the LOC with a combined (dermal + inhalation) MOE of 82; this 

scenario is mixing/loading a liquid formulation for aerial application to high acreage crops. With 

the addition of gloves, the combined dermal + inhalation MOE is 470, which is not of concern. 

All other scenarios result in risk estimates greater than 220 with baseline attire. The 

occupational post-application dermal exposure and risk estimates are greater than the LOC of 

100 on the day of application, ranging from 230 to 4,600 depending on crop and activity. 

 

1

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 23

2.2 Label Recommendations 

There are no label recommendations based on the proposed uses.

2.3 Data Deficiencies and Requirements

Dislodgeable Foliar Residue (DFR): 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 post-application dermal exposure. 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, the HED has decided 

that a calculated MOE of approximately 4 times higher than the level of concern (e.g., an MOE > 

400 if the LOC = 100) using the default dislodged residue values would provide an adequate 

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

(Guidance for Requiring/Waiving Turf Transferrable Residue (TTR) and Dislodgeable Foliar 

Residue (DFR) Studies. 12/12/2012, Exposure Science Advisory Council). A DFR study is 

required for flutriafol at this time since the dermal MOEs for leafy vegetables are less than 

4 times the LOC (i.e., 400) based on default values for the fraction of application rate 

available for transfer after a foliar application.

3.0 Hazard Characterization

Flutriafol has low acute toxicity via the oral, dermal and inhalation routes (Toxicity Categories 

III and IV). Flutriafol is minimally irritating to the eyes (Toxicity Category III) and is not a 

dermal irritant (Toxicity Category IV). Flutriafol was not shown to be a skin sensitizer when 

tested in guinea pigs (Buehler method). Table 3.1 presents a summary of the acute toxicity 

information for flutriafol.

Table 3.1. Acute Toxicity Profile – Flutriafol.

Guideline No. Study Type MRID(s) Results Toxicity Category

870.1100 Acute oral (rat) 47090336 LD50 = 1140 mg/kg (M); 

1480 mg/kg (F) III

870.1200 Acute dermal (rat) 47090337 LD50 > 2000 mg/kg III

870.1300 Acute inhalation (rat) 47090338 LC50 > 5.20 mg/L IV

870.2400 Primary eye irritation 

(rabbit) 47090339 Minimally irritating III

870.2500 Primary dermal irritation 

(rabbit) 47090341 Not a dermal irritant IV

870.2600 Dermal sensitization 

(guinea pigs) 47090343 Not a sensitizer -

Flutriafol appears to be generally equally toxic to rats, mice, and dogs with all three species 

having similar (within one order of magnitude) no-observed adverse-effect levels 
Page 7 of 23

(NOAELs)/lowest-observed adverse-effect levels (LOAELs). The target organ is the liver in 

dogs, rats and mice. Hepatotoxicity occurred at similar dose levels across several species and 

durations of exposure. Flutriafol is considered to be “Not likely to be Carcinogenic to Humans” 

based on the results of the carcinogenicity studies in rats and mice. 

The Hazard and Science Policy Council (HASPOC) met on December 12, 2013 to discuss the 

need for a subchronic inhalation toxicity study for flutriafol. Based on a weight of evidence 

approach, the HASPOC concluded that a subchronic inhalation toxicity study is not needed for 

flutriafol at this time for the following reasons: (1) flutriafol is category IV for acute toxicity 

through the inhalation route and the effects in that study were seen at a very high concentration 

of 5.2 mg/L; (2) following the ORE inhalation risk assessment, the lowest inhalation MOE is 

17,000; and (3) the HAPSOC waived the requirement for an inhalation study for cyproconazole, 

a similar broad spectrum triazole fungicide. 

A summary of the toxicological endpoints and doses chosen for the relevant exposure scenarios 

for human risk assessment are found in Table 3.2. The short- (1-30 days), and intermediate- (1-6 

months) term dermal and inhalation toxicological points of departure were identified from a 

prenatal developmental toxicity study in the rabbit where the effects were based on decreased 

number of live fetuses, complete litter resorptions and increased post-implantation loss. The 

NOAEL was 7.5 mg/kg. Flutriafol was classified as a “not likely” human carcinogen based on 

the carcinogenicity studies in rats and mice. 

The Agency’s level of concern for risks (i.e., target level for Margins of Exposure) is defined by 

the uncertainty factors that are applied to the assessment. The Agency applies a factor of 10X to 

account for interspecies extrapolation to humans from the animal test species and another factor 

of 10X to account for intra-species sensitivity. The total uncertainty factor that has been applied 

to occupational risk assessments is 100 for short- and intermediate- term dermal and inhalation 

exposures. 

Absorption

Since an oral study was used, a dermal absorption factor of 21% was used for the dermal risk 

assessment derived from a dermal penetration study (MRID 47090415). Since no inhalation 

absorption data are available, toxicity by the inhalation route is considered to be equivalent to the 

estimated toxicity by the oral route of exposure.

Body Weight

Since the dermal and inhalation PODs are based on developmental and/or fetal effects, the body 

weight appropriate for dermal and inhalation assessments is 69 kg.

Table 3.2: Summary of Toxicological Doses and Endpoints for Flutriafol.

Exposure/

Scenario

Point of 

Departure

Uncertainty/FQPA 

Safety Factors

RfD, PAD, 

Level of 

Concern for 

Risk 

Assessment

Study and Toxicological Effects
Page 8 of 23

Table 3.2: Summary of Toxicological Doses and Endpoints for Flutriafol.

Exposure/

Scenario

Point of 

Departure

Uncertainty/FQPA 

Safety Factors

RfD, PAD, 

Level of 

Concern for 

Risk 

Assessment

Study and Toxicological Effects

Dermal

Short (1-30 

days)- and 

Intermediate 

(1-6 months) -

Term 

NOAEL=7.5

mg/kg/day 

Dermal 

Absorption 

Factor = 21%

UFA = 10X

UFH = 10X

FQPA SF = 1X

Occupational 

LOC for MOE 

= 100

Developmental toxicity – rabbit

LOAEL = 15mg/kg, based on decreased number 

of live fetuses, complete litter resorptions and 

increased post-implantation loss. 

Inhalation 

Short (1-30 

days)- and 

Intermediate 

(1-6 months) -

Term 

NOAEL = 

7.5 

mg/kg/day

Inhalation 

toxicity 

assumed to 

be equivalent 

to oral 

toxicity.

UFA = 10X

UFH = 10X

FQPA SF = 1X

Occupational 

LOC for MOE 

= 100

Developmental toxicity – rabbit

LOAEL = 15 mg/kg, based on decreased number 

of live fetuses, complete litter resorptions and 

increased post-implantation loss. 

Cancer (oral, 

dermal, 

inhalation)

Classification: “Not likely to be Carcinogenic to Humans” based on the carcinogenicity studies in 

rats and mice. 

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 (intraspecies). UFH = 

potential variation in sensitivity among members of the human population (interspecies). FQPA SF = FQPA Safety Factor. MOE = margin of 

exposure. LOC = level of concern. 

4.0 Exposure and Use Profile 

Flutriafol is registered for use on a number of agricultural crops, including corn, grapes, 

soybeans, apples, peanuts, pome fruit, stone fruit, and sugarbeets. Based on the proposed new 

uses, it has been determined that the potential exposure scenarios that will need to be assessed 

include short- and intermediate-term occupational exposures (handler and post-application). A 

summary of the proposed use directions are included in Table 4.1 below. 

Table 4.1. Summary of Proposed Use Directions for Flutriafol.

Applic. Timing, Type, and 

Equip.

Formulation 

[EPA Reg. 

No.]

Application 

Rate

Max No. 

Applications 

per Season

Max 

Seasonal 

Application 

Rate

Use Directions and 

Limitations

Flutriafol® 250 g/L1 (67760-REN) 2.08 lb ai/gal (22.7% ai)

TopGuard® Fungicide1 (67760-75) 1.04 lb ai/gal (11.8% ai)

Flutriafol® 500 g/L1(67760-REA) 4.16 lb ai/gal (42% ai)

Brassica (cole) leafy vegetables, Celery, Leafy Vegetables

Apply preventatively or when 

conditions are favorable for 

disease. 

Groundboom or Aerial.

Liquid 

(67760-REN) 

0.114 lb 

ai/A

4 apps/growing 

season

0.455 lb ai/A

Do not apply via 

chemigation. REI = 12 

hours. RTI = 7 days. 

PHI = 7 days

Cotton

Apply preventatively or when Liquid 0.114 lb 2 foliar 0.488 lb ai/A Do not apply via 
Page 9 of 23

Table 4.1. Summary of Proposed Use Directions for Flutriafol.

Applic. Timing, Type, and 

Equip.

Formulation 

[EPA Reg. 

No.]

Application 

Rate

Max No. 

Applications 

per Season

Max 

Seasonal 

Application 

Rate

Use Directions and 

Limitations

conditions are favorable for 

disease. 

Groundboom or Aerial.

(67760-75) ai/A app/season (including 

both foliar 

and soil apps)

chemigation. REI = 12 

hours. RTI (for foliar 

applications) = 7 days. 

PHI = 30 days.

Applied at planting to the soil. 

Groundboom.

Liquid 

(67760-REA) 0.26 lb ai/A 1 soil app/season

Cucurbits (cucumbers, pumpkin, squash, watermelon, muskmelons)

Apply preventatively or when 

conditions are favorable for 

disease. 

Groundboom or Aerial.

Liquid 

(67760-75) 0.114 lb 

ai/A

4 apps/growing 

season

0.455 lb ai/A

Do not apply via 

chemigation. REI = 12 

hours. RTI = 7 days. 

PHI = 0 day.

Liquid 

(67760-REN) 

Pecans (and other tree nuts), Almonds and Walnuts

For Pecan Scab control, start 

application at bud break; 

continue 10-14 days prepollination and 14-21 days 

post-pollination. For all other 

diseases, apply preventatively 

or when conditions are 

favorable for disease. 

Airblast or Aerial.

Liquid 

(67760-75) 

0.114 lb 

ai/A

4 apps/growing 

season

0.455 lb ai/A

Do not apply via 

chemigation. REI = 12 

hours. RTI = 7 days. 

PHI = 14 days.

For Brown Rot Blossum

Blight, start applications at 5-

10% bloom, followed by an 

application at 50-100% bloom. 

For all other diseases, apply 

preventatively or when 

conditions are favorable for 

disease. 

Airblast or Aerial.

Liquid 

(67760-REN) 

Peppers (and Other Fruiting Vegetables), Tomatoes

Apply preventatively or when 

conditions are favorable for 

disease. 

Groundboom or Aerial.

Liquid 

(67760-75) 0.114 lb 

ai/A

4 apps/growing 

season

0.455 lb ai/A

Do not apply via 

chemigation. REI = 12 

hours. RTI = 7 days. 

PHI = 0 day.

Liquid 

(67760-REN) 

Wheat (spring and winter) and Triticale

For suppression of Fusarium 

Head Blight, apply at anthesis 

(or Pollination; beginning of 

flowering; Feekes Scale: 

10.51). For all other diseases, 

apply preventatively or when 

conditions are favorable for 

disease. 

Groundboom or Aerial.

Liquid 

(67760-75) 

0.114 lb 

ai/A

2 apps/growing 

season

0.203 lb ai/A

Do not apply via 

chemigation. REI = 12 

hours. RTI = 7 days. 

PHI = 30 days when 

grown for grain, 15 days 

when grown for hay, 0 

day when grown for 

forage.

Strawberry

Apply preventatively or when 

conditions are favorable for 

Liquid 

(67760-REN) 

0.114 lb 

ai/A

4 apps/growing 

season

0.455 lb ai/A Do not apply via 

chemigation. REI = 12 
Page 10 of 23

Table 4.1. Summary of Proposed Use Directions for Flutriafol.

Applic. Timing, Type, and 

Equip.

Formulation 

[EPA Reg. 

No.]

Application 

Rate

Max No. 

Applications 

per Season

Max 

Seasonal 

Application 

Rate

Use Directions and 

Limitations

disease. 

Groundboom or Aerial.

hours. RTI = 7 days. 

PHI = 0 day.

Sorghum

For Ergot, make first 

application at or just prior to 

planting. For all other 

diseases, apply preventatively 

or when conditions are 

favorable for disease. 

Groundboom or Aerial.

Liquid 

(67760-75) 

0.114 lb 

ai/A

4 apps/growing 

season

0.455 lb ai/A

Do not apply via 

chemigation. REI = 12 

hours. RTI = 7 days. 

PHI = 7 days.

1. PPE = LS shirt and long pants; CR gloves; shoes/socks

5.0 Residential Exposure and Risk Estimates

There are no residential uses proposed or currently registered for flutriafol. Therefore, 

residential handler and post-application exposure/risk were not assessed. 

5.1 Spray Drift

Spray drift is a potential source of exposure to those nearby pesticide applications. This is 

particularly the case with aerial application, but, to a lesser extent, spray drift can also be a 

potential source of exposure from the ground application methods (e.g., groundboom and 

airblast) employed for flutriafol. The Agency has been working with the Spray Drift Task Force 

(a task force composed of various registrants which was developed as a result of a Data Call-In 

issued by EPA), 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). 2 The Agency is also taking means to qualitatively and 

qualitatively address spray drift as a potential source of exposure in risk assessments for 

pesticides through existing programs such as Ag Drift and chemical specific properties of 

pesticides. The potential for spray drift will be quantitatively evaluated for each pesticide during 

the Registration Review process which ensures that all uses for that pesticide will be considered 

concurrently. 

5.2 Residential Bystander Post-Application Inhalation Exposure

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

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

inhalation toxicity (Toxicity Category IV) and the low vapor pressure (3.0 x 10-9 mmHg, 20°C). 

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 

 

2 Available: http://www.epa.gov/opp00001/factsheets/spraydrift.htm 
Page 11 of 23

Scientific Advisory Panel (SAP) in December 2009, and received the SAP’s final report on 

March 2, 20103. 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 postapplication inhalation exposure assessment for flutriafol.

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 the current labeling regarding types of equipment and 

techniques that can be used, occupational handler exposure is expected. The quantitative 

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

scenarios: 

1) Mixing/loading liquids for aerial, groundboom, and airblast applications;

2) Applying sprays via aerial, airblast and groundboom equipment; and

3) Flagging for aerial applications.

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: 

The application rates used in this assessment 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 Table4”, which, along with additional information on HED policy 

 

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

4 Available: http://www.epa.gov/opp00001/science/handler-exposure-table.pdf
Page 12 of 23

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

Agency website5.

Area Treated or Amount Handled: 

The inputs for area treated were based on information in ExpoSAC Policy 9.1 and include:

1200 and 350 acres for aerial application to high and typical acreage crops, respectively

200 and 80 acres for groundboom application to high and typical acreage crops, 

respectively

40 acres for airblast applications

350 acres for flaggers

 

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. 

For the proposed use patterns, short- and intermediate-term exposures are anticipated for the 

following reasons: (1) flutriafol is a fungicide that is recommended to be applied preventatively 

or when conditions favor disease; (2) up to 4 foliar applications can be made per season 7 days 

apart; and (3) commercial applicators may apply this product at various locations within a region 

over a period of weeks. In addition, the short- and intermediate-term PODs are the same; 

therefore, short-term risk estimates are protective of longer-term exposures.

Mitigation/Personal Protective Equipment: 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 socks, no protective gloves, and no respirator, as well as baseline with various levels 

of PPE as necessary (e.g., gloves, respirator, etc). The flutriafol product labels direct mixers, 

loaders, applicators and other handlers to wear long-sleeved shirt and long pants, shoes plus 

socks, and chemical-resistant gloves.

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:

Dermal and inhalation risk estimates were combined in this assessment, since the toxicological 

effects for these exposure routes were similar. 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)

 

5 Available: http://www.epa.gov/pesticides/science/handler-exposure-data.html
Page 13 of 23

Summary of Occupational Handler Non-Cancer Exposure and Risk Estimates

The occupational handler exposure and risk estimates indicate that the short- and intermediateterm dermal and inhalation combined MOEs are not of concern to HED (i.e., MOE > 100) with 

the use of chemical-resistant gloves as personal protective equipment as directed by the label. 

At the baseline level of personal protection (i.e., no gloves and no respirator), only one scenario 

results in a risk estimate below the LOC with a combined (dermal + inhalation) MOE of 82; this 

scenario is mixing/loading a liquid formulation for aerial application to high acreage crops. With 

the addition of gloves, the combined dermal + inhalation MOE is 470, which is not of concern. 

All other scenarios result in risk estimates greater than 220 with baseline attire.

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.

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.
Page 14 of 23

Table 6.1.1. Occupational Handler Non-Cancer Exposure and Risk Estimates for Flutriafol. 

Exposure 

Scenario Crop or Target

Dermal Unit 

Exposure 

(μg/lb ai)1

Inhalation 

Unit 

Exposure 

(μg/lb ai)1

Maximum 

Application 

Rate (lb 

ai/A)2

Area 

Treated 

(acres)3

Dermal

(LOC = 100)

Inhalation

(LOC = 100)

Total

(LOC = 

100)

Mitigation 

Level

Mitigation 

Level

Dose 

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

Mixer/Loader

Aerial application 

of liquid 

formulation

Brassica (cole) leafy vegetables, 

Celery, Leafy Vegetables, 

Cucurbits, Pecans (and other tree 

nuts), Almonds and Walnuts, 

Peppers (and Other Fruiting 

Vegetables), Tomatoes, 

Strawberry

220 

(baseline)

0.219 

(baseline)

0.114

350 0.0267 280 0.000127 59,000 280

Cotton, Wheat (spring and 

winter) and Triticale, Sorghum 1200

0.0916 82

0.000435 17,000

82

37.6 

(single layer 

w/gloves)

0.0156 480 470

Groundboom 

application of 

liquid formulation

Brassica (cole) leafy vegetables, 

Celery, Leafy Vegetables, 

Cucurbits, Pecans (and other tree 

nuts), Almonds and Walnuts, 

Peppers (and Other Fruiting 

Vegetables), Tomatoes, 

Strawberry 220 (baseline)

0.114

80 0.00612 1,200 0.000029 260,000 1,200

Wheat (spring and winter) and 

Triticale, Sorghum 200 0.0153 490 0.0000723 100,000 490

Cotton 0.26 200 0.0347 220 0.000165 45,000 220

Airblast

application of 

liquid formulation

Pecans (and other tree nuts), 

Almonds and Walnuts 0.114 40 0.00304 2,500 0.0000145 520,000 2,500

Applicator

Aerial spray 

application

Brassica (cole) leafy vegetables, 

Celery, Leafy Vegetables, 

Cucurbits, Pecans (and other tree 

nuts), Almonds and Walnuts, 

Peppers (and Other Fruiting 

2.08

(engineering 

control)

0.0049

(engineering 

control)

0.114 350 0.000253 30,000 0.00000284 2,600,000 30,000
Page 15 of 23

Table 6.1.1. Occupational Handler Non-Cancer Exposure and Risk Estimates for Flutriafol. 

Exposure 

Scenario Crop or Target

Dermal Unit 

Exposure 

(μg/lb ai)1

Inhalation 

Unit 

Exposure 

(μg/lb ai)1

Maximum 

Application 

Rate (lb 

ai/A)2

Area 

Treated 

(acres)3

Dermal

(LOC = 100)

Inhalation

(LOC = 100)

Total

(LOC = 

100)

Mitigation 

Level

Mitigation 

Level

Dose 

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

Vegetables), Tomatoes, 

Strawberry

Cotton, Wheat (spring and 

winter) and Triticale, Sorghum 1200 0.000867 8,700 0.00000971 770,000 8,600

Groundboom 

spray application

Brassica (cole) leafy vegetables, 

Celery, Leafy Vegetables, 

Cucurbits, Pecans (and other tree 

nuts), Almonds and Walnuts, 

Peppers (and Other Fruiting 

Vegetables), Tomatoes, 

Strawberry

78.6

(baseline)

0.34

(baseline)

0.114 80 0.00218 3,400 0.0000449 170,000 3,300

Wheat (spring and winter) and 

Triticale, Sorghum 0.114 200 0.00545 1,400 0.000112 67,000 1,400

Cotton 0.26 200 0.0124 600 0.000257 29,000 590

Airblast spray 

application

Pecans (and other tree nuts), 

Almonds and Walnuts

1770

(baseline)

4.71

(baseline) 0.114 40 0.0246 300 0.000312 24,000 300

Flagger

Flagger for aerial 

spray application

Brassica (cole) leafy vegetables, 

Celery, Leafy Vegetables, 

Cucurbits, Pecans (and other tree 

nuts), Almonds and Walnuts, 

Peppers (and Other Fruiting 

Vegetables), Tomatoes, 

Strawberry, Cotton, Wheat 

(spring and winter) and Triticale, 

Sorghum

11

(baseline)

0.35

(baseline)

0.114 350 0.00134 5,600 0.000203 37,000 4,900

Bolded MOEs are below the LOC of 100.

1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (March 2013); Level of mitigation: Baseline, PPE (gloves), Eng. Controls.

2 Based on proposed labels (Reg. No. 67760-REN, 67760-75, 67760-REA).

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) × Area Treated (A/day) × DAF (21 %) ÷ BW (69 kg).

5 Dermal MOE = Dermal NOAEL (7.5 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) × Area Treated (A/day) ÷ BW (69 kg).

7 Inhalation MOE = Inhalation NOAEL (7.5 mg/kg/day) ÷ Inhalation Dose (mg/kg/day).
Page 16 of 23

8 Total MOE = NOAEL (7.5 mg/kg/day) ÷ (Dermal Dose + Inhalation Dose).
Page 17 of 23

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 flutriafol at this time primarily because of the low acute 

inhalation toxicity (Toxicity Category IV) and low vapor pressure (3.0 x 10-9 mmHg, 20°C). 

However, there are multiple potential sources of post-application 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, 20106. 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 postapplication 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 flutriafol.

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 inhalation exposure. Therefore, it is expected that these 

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

inhalation exposure scenarios.

Furthermore, inhalation exposure during dusty mechanical activities such as shaking and 

mechanical harvesting of tree nuts is another potential source of post-application inhalation 

exposure. However, the airblast applicator scenario is believed to represent a reasonable worst 

case surrogate estimate of post-application inhalation exposure during these dusty mechanical 

harvesting activities. The non-cancer inhalation risk estimate for commercial airblast application 

is not of concern (i.e., MOE > 100).

 

6 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html
Page 18 of 23

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. A post-application assessment was not conducted for the soil application of flutriafol to 

cotton since it is applied at planting when no crop foliage is present. Currently, HED has no 

transfer coefficients or other data to assess post-application dermal exposures to soil by 

occupational workers. In general, such exposures are considered to be negligible. Therefore, for

the proposed soil-directed use for cotton, post-application exposures and risks to occupational 

workers were not assessed. 

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

days to six months as intermediate-term. For flutriafol, short- and intermediate-term exposures

are expected for the following reasons: (1) flutriafol is a fungicide that is recommended to be 

applied preventatively or when conditions favor disease; and (2) up to 4 foliar applications can 

be made per season 7 days apart. In addition, the short- and intermediate-term PODs are the 

same; therefore, short-term risk estimates are protective of longer-term exposures.

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 37” which, along with 

additional information about the ARTF data, can be found at the Agency website8. 

For this assessment, post-application dermal exposure was assessed for the activity with the 

highest transfer coefficient for each crop/crop group, and is considered to be protective of all 

other activities within that crop/crop group. 

Table 6.2.2.1. Summary of Post-Application Activities and Dermal Transfer Coefficients.

Crop Policy Crop Group 

Category

Crop 

Height

Foliage 

Density

Transfer 

Coefficients 

(cm2/hr)

Activities

Brassica (cole) leafy 

vegetables, Celery, Leafy 

Vegetables

Vegetable, head and 

stem Brassica

and

Vegetable, leafy

Low/High Min/Full 4,200

Scouting, Hand 

harvesting, Hand 

weeding, Topping

Cotton Field / row crop, low / 

medium Low Min/Full 210 Scouting

Cucurbits Vegetable, cucurbit Low Min/Full 1,900 Hand-set Irrigation

 

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

8 Available: http://www.epa.gov/pesticides/science/post-app-exposure-data.html
Page 19 of 23

Table 6.2.2.1. Summary of Post-Application Activities and Dermal Transfer Coefficients.

Crop Policy Crop Group 

Category

Crop 

Height

Foliage 

Density

Transfer 

Coefficients 

(cm2/hr)

Activities

Pecans (and other tree 

nuts), Almonds and 

Walnuts

Tree, "nut" High Full 1,400 Hand harvesting

Peppers (and Other 

Fruiting Vegetables), 

Tomatoes

Vegetable, fruiting Low/High Min/Full 1,900 Hand-set Irrigation

Wheat (spring and 

winter) and Triticale

Field / row crop, low / 

medium Low Min/Full 1,100 Scouting

Strawberry Berry, low Low Full 1,100 Hand harvesting

Sorghum Field / row crop, tall Low/High Min/Full 210 Scouting

Application Rate:

The application rates used in this assessment 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 flutriafol. 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 Dermal Exposure and Risk Estimate Equations

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 Dermal Risk Estimates

The short- and intermediate-term post-application exposure scenarios associated with the 

proposed uses for flutriafol are summarized in Table 6.2.2.2. All scenarios resulted in MOEs 

greater than the LOC of 100 (ranging from 230 to 4,600) on day 0 (12 hours after application) 

and, therefore, are not of concern to HED.

Table 6.2.2.2. Occupational Post-application Non-Cancer Exposure and Risk Estimates for Flutriafol.

Crop/Site Activities

Transfer 

Coefficient 

(cm2/hr)

Proposed 

Application 

Rate (lb ai/A)

DFR1 Dermal Dose 

(mg/kg/day)2

MOE3

(LOC = 

100)

Short- and Intermediate-term

Brassica (cole) 

leafy 

vegetables, 

Celery, Leafy 

Vegetables

Scouting, Hand 

harvesting, Hand 

weeding, Topping

4,200

0.114 0.32

0.033 230

Cotton Scouting 210 0.002 4,600
Page 20 of 23

Table 6.2.2.2. Occupational Post-application Non-Cancer Exposure and Risk Estimates for Flutriafol.

Crop/Site Activities

Transfer 

Coefficient 

(cm2/hr)

Proposed 

Application 

Rate (lb ai/A)

DFR1 Dermal Dose 

(mg/kg/day)2

MOE3

(LOC = 

100)

Short- and Intermediate-term

Cucurbits Hand-set Irrigation 1,900 0.015 510

Pecans (and 

other tree nuts), 

Almonds and 

Walnuts

Hand harvesting 1,400 0.011 690

Peppers (and 

Other Fruiting 

Vegetables), 

Tomatoes

Hand-set Irrigation 1,900 0.015 510

Wheat (spring 

and winter) and 

Triticale

Scouting 1,100 0.009 880

Strawberry Hand harvesting 1,100 0.009 880

Sorghum Scouting 210 0.002 4,600

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 (21%)] BW (69 kg).

3 MOE = POD (7.5 mg/kg/day) / Daily Dermal Dose. 

Restricted Entry Interval

The REI specified on the proposed label is based on the acute toxicity of flutriafol. Flutriafol has 

low acute toxicity via the oral, dermal and inhalation routes (Toxicity Categories III and IV). 

Flutriafol is minimally irritating to the eyes (Toxicity Category III) and is not a dermal irritant 

(Toxicity Category IV). Flutriafol was not shown to be a skin sensitizer when tested in guinea 

pigs (Buehler method). Short- and intermediate-term post-application 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 flutriafol. 
Page 21 of 23

Appendix A. Summary of Occupational Non-cancer Algorithms

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:

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
Page 22 of 23

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).

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:
Page 23 of 23

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).