Document ID: EPA-HQ-OPP-2012-0896-0024
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2018-11-30T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                         WASHINGTON, D.C. 20460      

                                                     	OFFICE OF CHEMICAL SAFETY
                                                      	AND POLLUTION PREVENTION
	

Date:	8/30/18							
					
Subject:	BROMOXYNIL.  Occupational and Residential Exposure Assessment for the Registration Review of Bromoxynil, Bromoxynil Phenyl and Bromoxynil Octanate

PC Code: 035301, 035302, 035303,128920
DP Barcode:  D448609
Decision No.: 535851
Registration No.: See Tables 4.1
Petition No.: NA
Regulatory Action: Registration Review
Risk Assessment Type: Occupational/Residential Exposure Assessment
Case No.: 1689-84-5, 1689-99-2, 3861-41-4, 56634-95-8
TXR No.: NA
CAS No.: 1689-84-5, 1689-99-2
MRID No.: NA
40 CFR: §180.324

FROM:	Seyed Tadayon, Chemist
      Risk Assessment Branch III
		Health Effects Division (HED, 7509P)

THROUGH	Thomas Moriarty, Branch Chief 
		Risk Assessment Branch III 
		Health Effects Division (7509P)

and

		Shalu Shelat, ExpoSAC Designated Reviewer
		Monica Hawkins, ExpoSAC Designated Reviewer
		Exposure Science Advisory Committee (ExpoSAC) / HED

TO: 		Nicole Zinn, Chemical Review Manager
      Pesticide Reevaluation Division (PRD) (7508P)

				

Introduction		

The Pesticide Re-evaluation Division (PRD) has requested that the Health Effects Division (HED) conduct an exposure and risk assessment to estimate the risk to human health that will result from the currently registered uses of bromoxynil in support of registration review. This memorandum serves as HED's assessment of the occupational and residential exposure and risk from existing uses of bromoxynil.  

It is HED policy to use the best available data to assess exposure.  Several sources of generic data were used in this assessment as surrogate data in the absence of chemical-specific data, including Pesticide Handlers Exposure Database Version 1.1 (PHED 1.1); the Agricultural Handler Exposure Task Force (AHETF) database; the Outdoor Residential Exposure Task Force (ORETF) database; the Agricultural Reentry Task Force (ARTF) database; and other registrant-submitted exposure monitoring studies (MRIDs 49884502 and 49884501).  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 8/30/2018.
                               Table of Contents

1.0 Executive Summary	4
2.0 Risk Assessment Conclusions and Recommendations	6
2.1 Summary of Risk Estimates	6
2.2 Label Recommendations from Occupational Assessment	8
2.3 Data Deficiencies and Requirements	8
3.0 Hazard Characterization	8
4.0 Use Profile	11
5.0 Residential Exposure and Risk Estimates	13
6.0 Non-Occupational Spray Drift Exposure and Risk Estimates	13
7.0 Non-Occupational Bystander Post-Application Inhalation Exposure and Risk Estimates	17
8.0 Occupational Exposure and Risk Estimates	17
8.1 Occupational Handler Exposure/Risk Estimates	17
8.2 Occupational Post-application Exposure/Risk Estimates	30
8.2.1 Occupational Post-application Inhalation Exposure/Risk Estimates	30
8.2.2 Occupational Post-application Dermal Exposure/Risk Estimates	30
Appendix A.  Summary of Occupational Non-cancer Algorithms	38
Appendix B.  Summary of Occupational and Residential Cancer Algorithms	41
Appendix C.  Summary of Spray Drift Algorithms	42
Appendix D.  Summary of Directions for Agricultural Occupational Uses of Bromoxynil	46

1.0 Executive Summary

HED has conducted an occupational and residential exposure assessment for Registration Review uses of the active ingredient (ai), bromoxynil.  Bromoxynil is a contact herbicide which is registered for application as the octanoic and/or heptanoic acid esters for control of broadleaf weeds. Since the bromoxynil octanoic and heptanoic esters are rapidly converted to the bromoxynil phenol, the exposure and tolerances are based on bromoxynil phenol (referred to as bromoxynil in the remainder of this document).

This memorandum contains HED's exposure and risk estimates to occupational pesticide handlers (i.e., mixers, loaders, applicators) and post-application exposure to re-entry workers.  There are no registered residential uses. However, a spray drift assessment for off-target movement of pesticides into residential settings was conducted for existing registered uses.    
 
Based on the Agency's current practices, a quantitative non-cancer occupational post-application inhalation exposure assessment was not performed for bromoxynil 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 bromoxynil.

Use Pattern
Bromoxynil is currently formulated as a liquid, registered for use on agricultural food crops including garlic and onions; food and feed crops including mint, flax, spearmint, peppermint, barley, oats, rye, triticale, wheat, sorghum, cotton, and corn (field and pop); and feed crops including alfalfa, forage/hay, and grass.  Current, non-food uses include outdoor industrial areas, non-agricultural uncultivated areas/soil, non-residential commercial/industrial lawns, shrubs/bushes/vines, and sod farms.  

Bromoxynil registered products are applied either via aerial, groundboom, or chemigation equipment. The use of a backpack or any type of handheld equipment is prohibited on all the registered labels.  Spot treatments should be applied only with a calibrated boom. Most of the bromoxynil product labels direct mixers, loaders, applicators, and other handlers to wear baseline attire (i.e., long-sleeved shirt, long pants, shoes and socks), coveralls, chemical resistant apron, gloves, protective eyewear, and respirators. The restricted entry intervals (REIs) range from 12 to 24 hours for most labels.  

Exposure Profile
Occupational handler and post-application exposure is expected to be both short- (1 to 30 days) and intermediate-term (1 to 6 months).  Exposures from spray drift are expected to be short-term only.  For occupational use patterns, dermal and inhalation exposures are anticipated for occupational handlers and post application workers.  

Hazard Characterization
Bromoxynil phenol has moderate acute toxicity (Toxicity Category II) via the oral and inhalation routes and low acute toxicity (Toxicity Category III) via the dermal route. It is a moderate eye irritant (Toxicity Category II) and is not a dermal irritant (Toxicity Category IV) or skin sensitizer.  Bromoxynil octanoate has moderate acute toxicity via the oral and dermal routes (Toxicity Category II) and low acute toxicity (Toxicity Category III) via the inhalation route.  It is a moderate eye irritant (Toxicity Category II) and is not a dermal irritant (Toxicity Category IV).  Bromoxynil octanoate is a skin sensitizer. 

Estimated short- and intermediate-term dermal exposures were compared to the no observed adverse effect level (NOAEL) of 10 mg/kg/day from a dermal developmental study in which increased incidence of supernumerary ribs were seen.  Estimated short- and intermediate-term inhalation exposures were compared to the NOAEL of 4 mg/kg/day from an oral developmental toxicity study in the rat based on increased incidence of supernumerary ribs.  

Short-term incidental oral NOAEL of 5 mg/kg/day has been selected to protect infants and children from the subchronic dog study. The Food Quality Protection Act (FQPA) Safety Factor (SF) was reduced from 10X to 1X.

The dermal, inhalation and oral level of concern (LOC) is equal to 100 based on an uncertainty factor (UF) of 100 to account for interspecies extrapolation (10X); intraspecies variation (10X); and the FQPA SF of 1X.

Bromoxynil is classified as a "possible human carcinogen" based on the presence of hepatocellular tumors in male mice.  The unit risk, Q1[*], of bromoxynil based upon male mouse hepatocellular tumors rates is 0.103 (mg/kg/day)[-1] in human equivalents (TXR 0050045, E. Budd and E. Rinde. 03/12/1997).  Mutagenicity tests were largely negative and did not raise a concern.  

Residential Exposure and Risk Assessment
There are no registered residential uses associated with bromoxynil; therefore, a quantitative handler and post-application assessment was not performed.

Spray Drift Exposure and Risks
Adult dermal risk estimates from aerial and groundboom applications are not of concern at the field edge.  

Dermal and hand-to-mouth risk estimates for children 1 < 2 years old from groundboom applications are not of concern at the field edge For aerial applications, hand-to-mouth risks are not of concern at the field edge; however, dermal risk estimates are of concern for several scenarios. 
Occupational Handler Exposure and Risk Assessment

Non-Cancer Exposure and Risk Estimates
Dermal MOEs range from 5.2 to 23,000, inhalation MOEs range from 2,100 to 1,800,000, and total MOEs range from 5.2 to 23,000 at baseline. All occupational handler inhalation risk estimates are not of concern at baseline attire (no respirator), while about a third of the dermal risks estimates are of concern at baseline (single layer, no gloves).  Of the eleven scenarios with dermal risks of concern at baseline, all but two are not of concern with consideration of increasing levels of dermal protection (e.g., double layer + gloves).  Two of the occupational handler exposure scenarios result in estimated risks of concern despite the addition of dermal protection (e.g., double layer + gloves). These two scenarios are not of concern with the use of engineering controls which result in dermal MOEs of 230 and 130 for mixing/loading liquids for applications to fallow land and mixing/loading liquids for applications to high-acreage field crops respectively.

Cancer Exposure and Risk Estimates
Occupational cancer risks were estimated for both private/farmer and contract/commercial handlers.  Cancer risks at baseline (single layer, no gloves, no respirator) range from 6E-07 to 4E[-]04 for private/farmer and 2E-06 to 1E-03 for contract/commercial handlers. With the addition of dermal and inhalation protection (double layer, gloves, P10 respirator), cancer risks range from 9E-08 to 5E-05 for private/farmer and 3E-07 to 1E-04 or contract/commercial handlers.  

Occupational Post-application Dermal Exposure and Risk Assessment

Non-Cancer Exposure and Risk Estimates
Several dermal post-application exposure scenarios resulted in MOEs lower than the LOC (100) on the day of treatment (i.e., day 0) and are of concern. These scenarios resulted in MOEs ranging from 14 to 310. 

Cancer Exposure and Risk Estimates
Cancer risks based on a 30-day average dose range from 1E-07 to 1E-05 .

Human Studies Review

This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical.  These data, which include studies from PHED 1.1; the AHETF database; the Outdoor Residential Exposure Task Force (ORETF) database 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 website.  

2.0 Risk Assessment Conclusions and Recommendations

2.1 Summary of Risk Estimates
Exposure and Risk Assessment
A residential handler exposure assessment was not conducted since bromoxynil is only applied to use sites that are not treated by residential handlers (e.g., grass grown for seed only, sod farms, non-residential turf, and non-cropland industrial sites).

Spray Drift Exposure and Risks
Adult dermal risks from groundboom and aerial  applications are not of concern at the field edge.  
Dermal and hand-to-mouth risk estimates for children 1 < 2 years old from groundboom applications are not of concern at the field edge. Hand-to-mouth risk estimates resulting  from aerial application, are not of concern at the field edge; however, dermal risks is of concern for the following scenarios:

 Aerial applications using fine to medium spray up to 10 feet from the field 
 Aerial applications using medium to coarse spray at edge 
 Aerial applications using coarse to very coarse spray at edge 
 Aerial applications using very fine to fine spray up to 100 feet from the field 
 Aerial applications using AT401, M, 10 mph, 37% SD configuration at edge and up to 10 feet from field Aerial applications using WASP, M, 10 mph, 37% SD and AT401, C, 10 mph, 25% SD at edge.
 
Occupational Handler Exposure and Risk Assessment

Non-Cancer Exposure and Risk Estimates
Dermal MOEs range from 5.2 to 23,000, inhalation MOEs range from 2,100 to 1,800,000, and total MOEs range from 5.2 to 23,000 wearing baseline attire. Occupational handler inhalation risk estimates are not of concern at baseline (no respirator), while about a third of the dermal risks estimates were of concern at baseline (single layer, no gloves).  Of the eleven scenarios with dermal risks of concern at baseline, all but two scenarios are not of concern with consideration of increasing levels of dermal protection.  The following two mixer/loader  exposure scenarios result in estimated risks of concern despite the addition of dermal protection (double layer + gloves): 

 Mixer/loader of liquid formulation for aerial applications to fallow land at 1.0 lb ai/A (Dermal MOE = 68, Total MOE = 67)
 Mixer/loader of liquid formulation for aerial applications to high-acreage field crop at 0.5 lb ai/A (Dermal MOE = 39, Total MOE = 38).

These two mixer/loader scenarios are not of concern with the use of engineering controls. The mixing/loading of liquids for applications to fallow land resulted in a dermal MOE of 230; while  mixing/loading liquids for applications to high-acreage field crops resulted in a dermal MOE of 
130.
 
Cancer Exposure and Risk Estimates
Occupational cancer risks were estimated for both private/farmer and contract/commercial handlers.  Cancer risks at baseline (single layer, no gloves, no respirator) range from 6E-07 to 4E-04 for private/farmer and 2E-06 to 1E-03 contract/commercial handlers. With the addition of dermal and inhalation protection (double layer, gloves, P10 respirator), cancer risks range from 9E-08 to 5E-05 for private/farmer and 3E-07 to 1E-04 or contract/commercial handlers  

Occupational Post-application Dermal Exposure and Risk Assessment

Non-Cancer Exposure and Risk Estimates
Several dermal post-application exposure scenarios resulted in MOEs lower than the LOC (MOE < 100) on the day of treatment (i.e., day 0) and are of concern. Risks were of concern (MOE < 100) for the following scenarios: 

 Irrigating (hand set) alfalfa, grasses grown for seed, and mint up to 1 day after application at 0.5 lb ai/A
 Scouting barley and wheat on the day of treatment at 0.5 lb ai/A
 Scouting flax on the day of treatment at 0.25 lb ai/A
 Irrigating (hand set) corn (field and pop) up to 1 days after application at 0.5 lb ai/A
 Hand weeding onion (green and bulb) up to 1 days after application at 0.375 lb ai/A
 Hand weeding garlic up to 3 days after application at 0.5 lb ai/A

Cancer Exposure and Risk Estimates
Cancer risks based on a 30-day average dose range from from 7E-07 to 3E-05.

2.2 Label Recommendations from Occupational Assessment 

None.

2.3 Data Deficiencies and Requirements
There are no data deficiencies or outstanding data requirements for the registered uses of bromoxynil

3.0 Hazard Characterization

Acute Toxicity
Bromoxynil phenol has moderate acute toxicity (Toxicity Category II) via the oral and inhalation routes and low acute toxicity (Toxicity Category III) via the dermal route. It is a moderate eye irritant (Toxicity Category II) and is not a dermal irritant (Toxicity Category IV) or skin sensitizer. 

Bromoxynil octanoate has moderate acute toxicity via the oral and dermal routes (Toxicity Category II) and low acute toxicity (Toxicity Category III) via the inhalation route.  It is a moderate eye irritant (Toxicity Category II) and is not a dermal irritant (Toxicity Category IV).  Bromoxynil octanoate is a skin sensitizer. 

Table 3.1.  Acute Toxicity of Bromoxynil Phenol and Bromoxynil Octanoate
                                   Guideline
                                     Study
                                    Species
                                    Results
                                 Tox. Category
                                   MRID No.
                          Bromoxynil Phenol Technical
870.1100
Acute oral toxicity
Rat
LD50 = 81 mg/kg  M
LD50 = 93 mg/kg  F
                                      II
                                   00124758
870.1200
Acute dermal toxicity
Rat
LD50 >= 2000 mg/kg (M, F)
                                      III
                                   00124758
870.1300
Acute inhalation toxicity
Rat
LC5O = 0.269 mg/L M 
LC5O = 0.150 mg/L F
                                      II
                                   43014701
870.2400
Primary eye irritation
Rabbit
Corneal opacity resolved within 3 days; iritis resolved within 4 days; conjunctival irritation persisted for 10 days.
                                      II
                                   00124758
870.2500
Primary skin irritation
Rabbit
Not an irritant
                                      IV
                                   00124758
870.2600
Dermal sensitization 
Guinea Pig
Not a sensitizer
                                   Negative
                                   42718701
                        Bromoxynil Octanoate Technical
870.1100
Acute oral toxicity
Rat
LD50 = 400 mg/kg  M
LD50 = 238 mg/kg  F
                                      II
                                   00124112
870.1100
Acute dermal toxicity
Rabbit
LD50> 2000 mg/kg  M
  abraded skin.
LD50 1310 mg/kg  F
  with intact skin.
LD50 = 1660 mg/kg  F
  with abraded skin.
                                      II
                                   00124112
870.1300
Acute inhalation toxicity
Rat
LC5O = 0.810 mg/L  M 
LC5O = 0.720 mg/L  F
                                      III
                                   42167101
870.2400
Primary eye irritation
Rabbit
Corneal opacity and irritation lasting 24-72 hrs. Cleared by 96 hrs.
                                      II
                                   00124112
870.2500
Primary skin irritation
Rabbit
Erythema for 72 hrs. No edema,
                                      IV
                                   00124112
870.2600
Dermal sensitization
Guinea Pig
Contact sensitizer in modified Draize test.
                                   Positive
                                   41879801

Toxicological PODs Used for Risk Assessment
Estimated short- and intermediate-term dermal exposures were compared to the NOAEL of 10 mg/kg/day from a dermal developmental study in which increased incidence of supernumerary ribs were seen.  Estimated short- and intermediate-term inhalation exposures were compared to the NOAEL of 4 mg/kg/day from an oral developmental toxicity study in the rat based on increased incidence of supernumerary ribs.  Short- and intermediate-term incidental oral POD has been selected to protect infants and children. The NOAEL of 5 mg/kg/day was selected from the subchronic dog study and was considered the most appropriate oral POD.  

The dermal, inhalation and incidental oral LOC is based on an uncertainty factor (UF) of 100 (interspecies extrapolation (10X) x  intraspecies variation (10X) x  FQPA Safety Factor (1X).

Bromoxynil is classified as a "possible human carcinogen" based on the presence of hepatocellular tumors in male and female mice.  The unit risk, Q1[*], of bromoxynil based upon male mouse hepatocellular tumors rates is 0.103 (mg/kg/day)[-1] in human equivalents.  (TXR 0050045, E. Budd and E. Rinde. 03/12/1997)  Mutagenicity tests were largely negative and did not raise a concern.  

Table 3.2 Summary of Toxicological Doses and Endpoints for Bromoxynil for Use in Non-Occupational Human Health Risk Assessments
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- Term (1-6 months) 
NOAEL= 10 mg/kg/day 
UFA= 10 x
UFH=10 x

Occupational LOC = 100
Dermal developmental toxicity study  -  Rats
The LOAEL of 15 mg/kg/day based on increased incidence of supernumerary (14th) ribs.
Incidental Oral
Short-Term 
(1-30 days)

NOAEL= 5 mg/kg/day
UFA= 10 x
UFH=10 x
FQPA SF=1x

LOC = 100
Subchronic Study in Dogs
The LOAEL for effects attributed to a single dose was 8 mg/kg based on panting.  In addition to panting, elevated rectal temperatures occurred at 16 mg/kg and above, and death occurred at 30 mg/kg and above after a single dose on day 1
Cancer (oral, dermal, inhalation)
Bromoxynil phenol has been classified by the HED Carcinogenicity Peer Review Committee (E. Budd and E. Rinde, 3/12/1997, TXR 0050045) as a Group C, possible human carcinogen, based on male mouse hepatocellular tumors.  The committee also recommended that a low dose extrapolation model (Q1*) be applied to the experimental animal tumor data for quantification of human risk.  Q1* = 0.103 (mg/kg/day)[-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.  UFA = extrapolation from animal to human (interspecies).  UFH = potential variation in sensitivity among members of the human population (intraspecies).  FQPA SF = FQPA Safety Factor. LOC = Level of Concern

Table 3.3 Summary of Toxicological Doses and Endpoints for Bromoxynil for Use in Occupational Human Health Risk Assessments
Exposure/
Scenario
Point of Departure
Uncertainty Factors
Level of Concern for Risk Assessment
Study and Toxicological Effects
Dermal Short- (1-30 days) and Intermediate- Term (1-6 months) 
NOAEL= 10 mg/kg/day 
UFA= 10 x
UFH=10 x

Occupational LOC = 100
Dermal developmental toxicity study  -  Rats
The LOAEL of 15 mg/kg/day based on increased incidence of supernumerary (14th) ribs.
Inhalation Short- (1-30 days) and Intermediate-Term (1-6 months) 
NOAEL= 4 mg/kg/day
UFA= 10 x
UFH=10 x

Occupational LOC = 100
Oral developmental toxicity study in rats. NOAEL of 4 mg/kg/day was selected from one study (MRID 40466802, LOAEL =   mg/kg/day) and the LOAEL of 5 mg/kg/day was selected from another study (MRID 00116558, NOAEL not established).  Both studies showed a dose-related increased incidence of supernumerary ribs at the LOAEL.  
Cancer (oral, dermal, inhalation)
Bromoxynil phenol has been classified by the HED Carcinogenicity Peer Review Committee (E. Budd and E. Rinde, 3/12/1997, TXR 0050045) as a Group C, possible human carcinogen, based on male mouse hepatocellular tumors.  The committee also recommended that a low dose extrapolation model (Q1*) be applied to the experimental animal tumor data for quantification of human risk.  Q1* = 0.103 (mg/kg/day)[-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.  UFA = extrapolation from animal to human (interspecies).  UFH = potential variation in sensitivity among members of the human population (intraspecies).   LOC = level of concern.  . LOC = Level of Concern

Absorption
Since the short- and intermediate-term dermal POD was based on a route-specific toxicity study, no absorption factor was necessary to estimate dermal exposure in the non-cancer assessment. For the cancer assessment, the Q1* is based on an oral study; a dermal absorption factor of 17% was used. 

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 for both the non-cancer and cancer assessments.

Body Weight
For the occupational non-cancer assessment, the dermal and inhalation PODs are based on developmental and/or fetal effects, therefore, the body weight appropriate for dermal and inhalation assessments is 69 kg.  For purposes of performing a spray drift assessment an adult body weight of 69 kg and child (1 < 2 yrs old) body weight of 11 kg was used.  Finally, in order to perform the occupational cancer assessment, a  standard body weight for the general population (80 kg) was used since the cancer endpoint was not based on developmental and/or fetal effects.

4.0 Use Profile 

Bromoxynil is currently formulated as a liquid formulation, and registered for use on agricultural food crops including garlic and onions; food and feed crops including mint, flax, spearmint, peppermint, barley, oats, rye, triticale, wheat, sorghum, cotton, and corn (field and pop); and feed crops including alfalfa, forage/hay, and grass.  Current, non-food uses include outdoor industrial areas, nonagricultural uncultivated areas/soil, non-residential commercial/industrial lawns, shrubs/bushes/vines, and sod farms.  

Bromoxynil registered products are applied either via aerial, groundboom, or chemigation equipment. Most of the bromoxynil product labels direct mixers, loaders, applicators, and other handlers to wear baseline attire (i.e., long-sleeved shirt, long pants, shoes and socks), coveralls, chemical resistant apron and gloves, protective eyewear, and respirators. The restricted entry intervals (REIs) range from 12 to 24 hours for registered labels.  

A summary of the representative registered commercial end-use products and use sites with the highest application rates provided by PLUS report (4/12/18) is provided in Table D.1 in appendix D.   

5.0 Residential Exposure and Risk Estimates

A residential handler and post-application exposure assessment is not required for bromoxynil since there are no registered direct residential uses at this time

6.0 Non-Occupational Spray Drift Exposure and Risk Estimates

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) employed for bromoxynil.  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).   The Agency has also developed a policy on how to appropriately consider spray drift as a potential source of exposure in risk assessments for 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.  The approach is outlined in the revised (2012) Standard Operating Procedures For Residential Risk Assessment (SOPs) - Residential Exposure Assessment Standard Operating Procedures Addenda 1: Consideration of Spray Drift.  This document outlines the quantification of indirect non-occupational exposure to drift.  

Off-target movement of pesticides can occur via many types of pathways and it is governed by a variety of factors.  Sprays that are released and do not deposit in the application area end up off-target and can lead to exposures to those it may directly contact.  They can also deposit on surfaces where contact with residues can eventually lead to indirect exposures (e.g., children playing on lawns where residues have deposited next to treated fields).  The potential risk estimates from these residues can be calculated using drift modeling coupled with methods employed for residential risk assessments for turf products.

The approach to be used for quantitatively incorporating spray drift into risk assessment is based on a premise of compliant applications which, by definition, should not result in direct exposures to individuals because of existing label language and other regulatory requirements intended to prevent them.  Direct exposures would include inhalation of the spray plume or being sprayed directly.  Rather, the exposures addressed here are thought to occur indirectly through contact with impacted areas, such as residential lawns, when compliant applications are conducted.  Given this premise, exposures for children (1 to 2 years old) and adults who have contact with turf where residues are assumed to have deposited via spray drift thus resulting in an indirect exposure are the focus of this analysis analogous to how exposures to turf products are considered in risk assessment.  

In order to evaluate the drift potential and associated risks, an approach based on drift modeling coupled with techniques used to evaluate residential uses of pesticides was utilized. Essentially, a residential turf assessment based on exposure to deposited residues has been completed to address drift from the agricultural applications of bromoxynil.  In the spray drift scenario, the deposited residue value was determined based on the amount of spray drift that may occur at varying distances from the edge of the treated field using the AgDrift (v2.1.1) model and the Residential Exposure Assessment Standard Operating Procedures Addenda 1: Consideration of Spray Drift Policy. Once the deposited residue values were determined, the remainder of the spray drift assessment was based on the algorithms and input values specified in the recently revised (2012) Standard Operating Procedures for Residential Risk Assessment (SOPs). 

A screening approach was developed based on the use of the AgDrift model in situations where specific label guidance that defines application parameters is not available. AgDrift is appropriate for use only when applications are made by aircraft, airblast orchard sprayers, and groundboom sprayers.  When AgDrift was developed, a series of screening values (i.e., the Tier 1 option) were incorporated into the model and represent each equipment type and use under varied conditions.  The screening options specifically recommended in this methodology were selected because they are plausible and represent a reasonable upper bound level of drift for common application methods in agriculture.  These screening options are consistent with how spray drift is considered in a number of ecological risk assessments and in the process used to develop drinking water concentrations used for risk assessment.  In all cases, each scenario is to be evaluated unless it is not plausible based on the anticipated use pattern (e.g., herbicides are not typically applied to tree canopies) or specific label prohibitions (e.g., aerial applications are not allowed).  The screening level drift related risk estimates are presented below.  In many cases, risks are of concern when the screening level estimates for spray drift are used as the basis for the analysis.  In order to account for this issue and to provide additional risk management options additional spray drift deposition fractions were also considered.  These drift estimates represent plausible options for pesticide labels. 

The spray drift risk estimates are based on an estimated deposited residue concentration as a result of the screening level agricultural application scenarios.  Bromoxynil is applied on fallow land via aerial and groundboom equipment at a maximum application rate of 1.0 lb ai/A. Exposures were considered for 50 feet wide lawns where the nearest side of the property was directly adjoining the treated field (at field edge) and at varied distances up to 300 feet downwind of a treated field.  

Furthermore, spray drift risk estimates were refined by using chemical-specific turf transferable residue (TTR) data submitted for bromoxynil (MRID 49884501). The study has been reviewed by HED and was found to be acceptable for risk assessment. The predicted DAT-0 residue value of 0.041 ug/cm2 from the Georgia site (non-irrigated plot) was used in the assessment, adjusted for differences in application rates between study and label.  Adjusted TTR value of 0.080 ug/cm2 was used to estimate risks. For a more detailed summary of the study, see Section 8.2.2.

Dermal risks were estimated for adults and children; incidental oral risk estimates were calculated for children 1 < 2 years old. The level of concern (LOC) is 100 so MOEs < 100 would be of concern.  Results are presented in Tables 6.1 (adults) and 6.2 (children 1 < 2 years old).  

For adults (Table 6.1), dermal risks from groundboom applications are not of concern at the field edge. Most dermal risks are not of concern for aerial applications. Aerial applications using very fine to fine spray type resulted in dermal MOEs ranging from 85 at the field edge and 93 at a distance of 10 feet. Dermal MOEs did not reach 100 until 25 feet.

For children 1 < 2 years old (Table 6.2), dermal and hand-to-mouth risk estimates from groundboom applications are not of concern at the field edge. For aerial applications, hand-to-mouth risks are not of concern at the field edge; however, dermal risk estimates is of concern for the following scenarios:

 Aerial applications using fine to medium spray up to 10 feet from the field 
 Aerial applications using medium to coarse spray at edge 
 Aerial applications using very fine to fine spray up to 100 feet from the field 
 Aerial applications using AT401, M, 10 mph, 37% SD configuration at edge risks) 
 Aerial applications using WASP, M, 10 mph, 37% SD and AT401, C, 10 mph, 25% SD at edge 

Table 6.1. Residential Exposure due to Agricultural Drift - Adults
                                Crop/Rate Group
                       Spray Type/ Nozzle Configuration 
                                    At Edge 
                                    10 Feet 
                                   25 Feet  
                                    50 Feet 
                                    75 Feet 
                                   100 Feet 
                                   125 Feet 
                                   150 Feet 
                                   200 Feet 
                                   250 Feet 
                                   300 Feet 
Fallow land (Application Rate = 1.0 lb ai/A; Adjusted TTR = 0.0804 ug/cm[2]) 
                                 Dermal MOE[1]
                                    Aerial
                                Fine to Medium
                                      120
                                      150
                                      190
                                      250
                                      320
                                      420
                                      500
                                      590
                                      780
                                      930
                                     1,100

                               Medium to Coarse
                                      150
                                      200
                                      280
                                      390
                                      550
                                      720
                                      910
                                     1,100
                                     1,500
                                     2,000
                                     2,400

                             Coarse to Very Coarse
                                      170
                                      260
                                      390
                                      600
                                      860
                                     1,100
                                     1,400
                                     1,800
                                     2,400
                                     3,200
                                     4,000

                               Very Fine to Fine
                                      85
                                      93
                                      100
                                      120
                                      140
                                      160
                                      180
                                      210
                                      250
                                      290
                                      330

                           AT401, M, 10 mph, 37% SD
                                      140
                                      170
                                      220
                                      300
                                      410
                                      530
                                      650
                                      760
                                      990
                                     1,200
                                     1,500

                            WASP, M, 10 mph, 37% SD
                                      150
                                      190
                                      250
                                      370
                                      500
                                      650
                                      790
                                      930
                                     1,200
                                     1,500
                                     1,800

                           AT401, C, 10 mph, 25% SD
                                      160
                                      230
                                      320
                                      470
                                      680
                                      880
                                     1,100
                                     1,300
                                     1,900
                                     2,400
                                     2,900

                            WASP, C, 10 mph, 25% SD
                                      190
                                      260
                                      380
                                      600
                                      840
                                     1,100
                                     1,400
                                     1,800
                                     2,400
                                     3,200
                                     3,500

                           AT401, VC, 10 mph, 20% SD
                                      180
                                      280
                                      440
                                      720
                                     1,000
                                     1,400
                                     1,800
                                     2,300
                                     3,200
                                     4,000
                                     5,300

                           WASP, VC, 10 mph, 20% SD
                                      230
                                      360
                                      560
                                      880
                                     1,300
                                     1,700
                                     2,300
                                     2,600
                                     4,000
                                     4,500
                                     5,300
                                  Groundboom
                          High Boom Very fine to Fine
                                      170
                                      340
                                      570
                                      910
                                     1,300
                                     1,600
                                     1,900
                                     2,300
                                     2,900
                                     4,000
                                     4,500

                          Low Boom Very fine to Fine
                                      370
                                      990
                                     1,600
                                     2,400
                                     3,200
                                     4,000
                                     4,500
                                     5,300
                                     6,400
                                     7,900
                                    11,000

                        High Boom Fine to Medium/Coarse
                                      650
                                     1,700
                                     2,400
                                     3,500
                                     4,500
                                     5,300
                                     6,400
                                     6,400
                                     7,900
                                    11,000
                                    11,000

                        Low Boom Fine to Medium/Coarse
                                      960
                                     2,600
                                     4,000
                                     5,300
                                     6,400
                                     7,900
                                    11,000
                                    11,000
                                    16,000
                                    16,000
                                    16,000
1	Dermal MOE = Dermal POD (10 mg/kg/day) / Dermal Dose (mg/kg/day).

Table 6.2. Residential Exposure due to Agricultural Drift - Children 1<2 years old
                                Crop/Rate Group
                       Spray Type/ Nozzle Configuration 
                                    At Edge 
                                    10 Feet 
                                   25 Feet  
                                    50 Feet 
                                    75 Feet 
                                   100 Feet 
                                   125 Feet 
                                   150 Feet 
                                   200 Feet 
                                   250 Feet 
                                   300 Feet 
Fallow land (Application Rate = 1.0 lb ai/A; Adjusted TTR = 0.0804 ug/cm[2]) 
                                 Dermal MOE[1]
                                    Aerial
                                Fine to Medium
                                      72 
                                      89 
                                     110 
                                     140 
                                     190 
                                      240 
                                     300 
                                     340 
                                     450 
                                     550 
                                     660 

                               Medium to Coarse
                                             88 
                                            120 
                                            160 
                                            230 
                                            320 
                                            420 
                                            530 
                                            640 
                                            890 
                                           1,200 
                                           1,400 

                             Coarse to Very Coarse
                                            100 
                                            150 
                                            230 
                                            350 
                                            500 
                                            660 
                                            850 
                                          1,000 
                                          1,400 
                                           1,900 
                                           2,300 

                               Very Fine to Fine
                                             50 
                                              55 
                                              61 
                                              71 
                                              82 
                                              94 
                                            110 
                                            120 
                                            150 
                                              170 
                                              200 

                           AT401, M, 10 mph, 37% SD
                                             80 
                                            100 
                                            130 
                                            180 
                                            240 
                                            310 
                                            380 
                                            440 
                                            580 
                                              720 
                                              890 

                            WASP, M, 10 mph, 37% SD
                                             85 
                                            110 
                                            140 
                                            220 
                                            300 
                                            380 
                                            470 
                                            550 
                                            720 
                                              890 
                                           1,000 

                           AT401, C, 10 mph, 25% SD
                                             94 
                                            130 
                                            190 
                                            280 
                                            400 
                                            520 
                                            640 
                                            780 
                                          1,100 
                                           1,400 
                                           1,700 

                            WASP, C, 10 mph, 25% SD
                                            110 
                                            150 
                                            220 
                                            350 
                                            490 
                                            660 
                                            810 
                                          1,000 
                                          1,400 
                                           1,900 
                                           2,100 

                           AT401, VC, 10 mph, 20% SD
                                            110 
                                            160 
                                            260 
                                            420 
                                            600 
                                            810 
                                          1,000 
                                          1,300 
                                          1,900 
                                           2,300 
                                           3,100 

                           WASP, VC, 10 mph, 20% SD
                                            130 
                                            210 
                                            330 
                                            520 
                                            740 
                                            980 
                                          1,300 
                                          1,600 
                                          2,300 
                                           2,700 
                                           3,100 
                                  Groundboom
                          High Boom Very fine to Fine
                                            100 
                                            200 
                                            330 
                                            530 
                                            740 
                                            930 
                                          1,100 
                                          1,300 
                                          1,700 
                                           2,300 
                                           2,700 

                          Low Boom Very fine to Fine
                                            220 
                                            580 
                                            930 
                                          1,400 
                                          1,900 
                                          2,300 
                                          2,700 
                                          3,100 
                                          3,700 
                                           4,700 
                                           6,200 

                        High Boom Fine to Medium/Coarse
                                            380 
                                            980 
                                          1,400 
                                          2,100 
                                          2,700 
                                          3,100 
                                          3,700 
                                          3,700 
                                          4,700 
                                           6,200 
                                           6,200 

                        Low Boom Fine to Medium/Coarse
                                            560 
                                          1,600 
                                          2,300 
                                          3,100 
                                          3,700 
                                          4,700 
                                          6,200 
                                          6,200 
                                          9,300 
                                           9,300 
                                           9,300 
                                   HtM MOE2 
                                    Aerial
                                Fine to Medium
                                         1,800 
                                         2,200 
                                         2,700 
                                         3,500 
                                         4,600 
                                         6,000 
                                         7,200 
                                         8,400 
                                       11,000 
                                       13,000 
                                       16,000 

                               Medium to Coarse
                                         2,200 
                                         2,900 
                                         3,900 
                                         5,500 
                                         7,800 
                                       10,000 
                                       13,000 
                                       16,000 
                                       22,000 
                                       28,000 
                                       35,000 

                             Coarse to Very Coarse
                                         2,500 
                                         3,700 
                                         5,500 
                                         8,600 
                                       12,000 
                                       16,000 
                                       21,000 
                                       25,000 
                                       35,000 
                                       45,000 
                                       57,000 

                               Very Fine to Fine
                                         1,200 
                                         1,300 
                                         1,500 
                                         1,700 
                                         2,000 
                                         2,300 
                                         2,600 
                                         2,900 
                                         3,600 
                                         4,200 
                                         4,800 

                           AT401, M, 10 mph, 37% SD
                                         1,900 
                                         2,500 
                                         3,200 
                                         4,300 
                                         5,800 
                                         7,600 
                                         9,300 
                                       11,000 
                                       14,000 
                                       17,000 
                                       22,000 

                            WASP, M, 10 mph, 37% SD
                                         2,100 
                                         2,700 
                                         3,500 
                                         5,300 
                                         7,200 
                                         9,300 
                                       11,000 
                                       13,000 
                                       17,000 
                                       22,000 
                                       25,000 

                           AT401, C, 10 mph, 25% SD
                                         2,300 
                                         3,200 
                                         4,600 
                                         6,800 
                                         9,700 
                                       13,000 
                                       16,000 
                                       19,000 
                                       27,000 
                                       35,000 
                                       41,000 

                            WASP, C, 10 mph, 25% SD
                                         2,700 
                                         3,800 
                                         5,400 
                                         8,600 
                                       12,000 
                                       16,000 
                                       20,000 
                                       25,000 
                                       35,000 
                                       45,000 
                                       50,000 

                           AT401, VC, 10 mph, 20% SD
                                         2,600 
                                         3,900 
                                         6,300 
                                       10,000 
                                       15,000 
                                       20,000 
                                       25,000 
                                       32,000 
                                       45,000 
                                       57,000 
                                       76,000 

                           WASP, VC, 10 mph, 20% SD
                                         3,300 
                                         5,200 
                                         8,000 
                                       13,000 
                                       18,000 
                                       24,000 
                                       32,000 
                                       38,000 
                                       57,000 
                                       65,000 
                                       76,000 
                                  Groundboom
                          High Boom Very fine to Fine
                                         2,400 
                                         4,900 
                                         8,100 
                                       13,000 
                                       18,000 
                                       23,000 
                                       27,000 
                                       32,000 
                                       41,000 
                                       57,000 
                                       65,000 

                          Low Boom Very fine to Fine
                                         5,300 
                                       14,000 
                                       23,000 
                                       35,000 
                                       45,000 
                                       57,000 
                                       65,000 
                                       76,000 
                                       91,000 
                                      110,000 
                                      150,000 

                        High Boom Fine to Medium/Coarse
                                         9,300 
                                       24,000 
                                       35,000 
                                       50,000 
                                       65,000 
                                       76,000 
                                       91,000 
                                       91,000 
                                      110,000 
                                      150,000 
                                      150,000 

                        Low Boom Fine to Medium/Coarse
                                       14,000 
                                       38,000 
                                       57,000 
                                       76,000 
                                       91,000 
                                      110,000 
                                      150,000 
                                      150,000 
                                      230,000 
                                      230,000 
                                      230,000 
1	Dermal MOE = Dermal POD (10 mg/kg/day) / Dermal Dose (mg/kg/day).
2	Hand to Mouth MOE = Incidental Oral POD (5 mg/kg/day) / Hand to Mouth Dose (mg/kg/day).3

7.0 Non-Occupational Bystander Post-Application Inhalation Exposure and Risk Estimates

The Agency has also developed a preliminary bystander volatilization inhalation exposure assessment for bromoxynil utilizing the currently available inhalation toxicity and air monitoring data.  There is one air monitoring studies available for bromoxynil that was conducted at the request of California Department of Pesticide Regulation (CDPR) http://www.cdpr.ca.gov/docs/emon/pubs/tac/bromoxynil.pdf "Ambient Air Monitoring after an
Application of Bromoxynil in Imperial County during January 1995."

At the request of California Department of Pesticide Regulation, the Air Resources Board (ARB) conducted a three-day source impacted ambient monitoring for an application of bromoxynil (end-use product: Buctril) to an onion field in program Imperial County during January of 1995. 

This monitoring was a follow-up to similar sampling conducted in January of 1992
which found low (0.02 to 2.34 ug/m[3]), but measurable levels of bromoxynil.

The results from the 1992 data were found to be not representative due to the placement of the monitors and unusual wind patterns. At that time, samplers were located upwind and downwind of the field based on prevailing winds. With the approval of the DPR, ARB conducted a second study by placing four samplers, one placed on each side of the field. No field conditions were observed to explain the lower levels found in this second study, although a lower application rate (one pint per acre versus 1.3 pints per acre) and a different crop (onions versus wheat) may have affected the levels detected. There is no route specific inhalation study available for conducting a bystander post-application inhalation exposure assessment.  Also no sample analyzed contained bromoxynil above the detection limit (0.04 ug/sample). Therefore, a bystander post-application inhalation exposure assessment was not conducted.

8.0 Occupational Exposure and Risk Estimates

8.1 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 registered use patterns and current labeling, types of equipment and techniques that can potentially be used, occupational handler exposure is expected from the registered uses.  The quantitative exposure/risk assessment developed for occupational handlers is based on the scenarios listed in Table 8.1.1.

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 registered application rates for bromoxynil are listed 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 Table", 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. 

Area Treated or Amount Handled:  The area treated/amount handled are based on ExpoSAC Policy 9.1.

Exposure Duration: HED classifies exposures from 1 to 30 days as short-term and exposures 30 days to six months as intermediate-term.  Exposure duration is determined by many things, including the exposed population, the use site, the pest pressure triggering the use of the pesticide, and the cultural practices surrounding that use site.  For most agricultural uses, it is reasonable to believe that occupational handlers will not apply the same chemical every day for more than a one-month time frame; however, there may be a large agribusiness and/or commercial applicators who may apply a product over a period of weeks (e.g., completing multiple applications for multiple clients within a region).  

For bromoxynil, based on the existing uses, both short- and intermediate-term exposures are expected for occupational handlers because it could be applied multiple times per season to many registered use sites.

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 bromoxynil product labels direct mixers, loaders, applicators, and other handlers to wear baseline attire (i.e., long-sleeved shirt, long pants, shoes and socks), coveralls, chemical resistant apron and gloves, protective eyewear, and respirators.

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 = 1 / (1/Dermal MOE) + (1/Inhalation MOE)

Summary of Occupational Handler Non-Cancer Exposure and Risk Estimates
Dermal MOEs range from 5.2 to 23,000, inhalation MOEs range from 2,100 to 1,800,000, and Total MOEs range from 5.2 to 23,000 at baseline. All occupational handler inhalation risk estimates are not of concern at baseline attire (no respirator), while about a third of the dermal risks estimates were of concern at baseline (single layer, no gloves).  Of the eleven scenarios with dermal risks of concern at baseline, all but two are not of concern with consideration of lable recommended dermal PPE (double layer clothing + gloves).  The following occupational handler exposure scenarios result in estimated risks of concern despite the addition of dermal protection (double layer clothing + gloves): 

 Mixer/loader of liquid formulation for aerial applications to fallow land at 1.0 lb ai/A (Dermal MOE = 68, Total MOE = 67)
 Mixer/loader of liquid formulation for aerial applications to high-acreage field crop at 0.5 lb ai/A (Dermal MOE = 39, Total MOE = 38).

These two mixer/loader scenarios are not of concern with the use of engineering controls; the dermal MOEs are 230 for mixing/loading liquids for applications to fallow land and 130 for mixing/loading liquids for applications to high-acreage field crops.

The Agency matches quantitative occupational exposure assessment with appropriate characterization of exposure potential. While HED presents quantitative risk estimates for human flaggers where appropriate, agricultural aviation has changed dramatically over the past two decades. According the 2012 National Agricultural Aviation Association (NAAA) survey of their membership, the use of GPS for swath guidance in agricultural aviation has grown steadily from the mid 1990's. Over the same time period, the use of human flaggers for aerial pesticide applications has decreased steadily from ~15% in the late 1990's to only 1% in the most recent (2012) NAAA survey. The Agency will continue to monitor all available information sources to best assess and characterize the exposure potential for human flaggers in agricultural aerial applications.

HED has no data to assess exposures to pilots using open cockpits.  The only data available is for exposure to pilots in enclosed cockpits.  Therefore, risks to pilots are assessed using the engineering control (enclosed cockpits) and baseline attire (long-sleeve shirt, long pants, shoes, and socks); per the Agency's Worker Protection Standard stipulations for engineering controls, pilots are not required to wear protective gloves for the duration of the application.  With this level of protection, there are no risk estimates of concern for applicators.

Table 8.1.1.  Occupational Handler Non-Cancer Exposure and Risk Estimates for Bromoxynil
                               Exposure Scenario
                                Crop or Target
                     Dermal Unit Exposure[1] 
(μg/lb ai)
                    Inhalation
Unit
Exposure[1]
(μg/lb ai)
                          Maximum
Application Rate[2]
                    Area Treated /
Amount Handled Daily[3]
                                    Dermal
                                  Inhalation
                                     Total

                              Dose (mg/kg/day)[4]
                                    MOE[5]
                              Dose (mg/kg/day)[6]
                                    MOE[7]
                                    MOE[8]
                                 Mixer/Loader
                Mixing/Loading Liquids for Aerial Applications
                    Roads, parking lots, etc. (pre-paving)
                                      220
                                     0.219
                               0.522 lb ai/acre
                                   60 acres
                                    0.0999
                                      100
                                   0.0000994
                                     40000
                                      100
                                       
                         Field-grown ornamental crops
                                      220
                                     0.219
                               0.368 lb ai/acre
                                   40 acres
                                     0.047
                                      210
                                    0.00322
                                     86000
                                      210
                                       
                                      Sod
                                      220
                                     0.219
                               0.522 lb ai/acre
                                   350 acres
                                     0.583
                                      17
                                    0.00058
                                     6900
                                      17
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0996
                                      100
                                       
                                       
                                      99
                                       
                              Field crop, typical
                                      220
                                     0.219
                                0.5 lb ai/acre
                                   350 acres
                                     0.558
                                      18
                                   0.000555
                                     7200
                                      18
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0954
                                      100
                                       
                                       
                                      100
                                       
                                  Fallow land
                                      220
                                     0.219
                                 1 lb ai/acre
                                   350 acres
                                     1.12
                                      8.9
                                    0.00111
                                     3600
                                      8.9
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                     0.191
                                      52
                                       
                                       
                                      51
                                       
                                       
                                  29.1 (DL/G)
                                       
                                       
                                       
                                     0.148
                                      68
                                       
                                       
                                      67
                                       
                                       
                                   8.6 (EC)
                                  0.083 (EC)
                                       
                                       
                                    0.0436
                                      230
                                   0.000422
                                     9500
                                      220
                                       
                           Field crop, high-acreage
                                      220
                                     0.219
                                0.5 lb ai/acre
                                  1200 acres
                                     1.91
                                      5.2
                                    0.0019
                                     2100
                                      5.2
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                     0.328
                                      30
                                       
                                       
                                      30
                                       
                                       
                                  29.1 (DL/G)
                                       
                                       
                                       
                                     0.254
                                      39
                                       
                                       
                                      38
                                       
                                       
                                   8.6 (EC)
                                  0.083 (EC)
                                       
                                       
                                    0.0748
                                      130
                                   0.000722
                                     5500
                                      130
              Mixing/Loading Liquids for Chemigation Applications
                                       
                                      Sod
                                      220
                                     0.219
                                0.5 lb ai/acre
                                   350 acres
                                     0.558
                                      18
                                   0.000555
                                     7200
                                      18
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0954
                                      100
                                       
                                       
                                      99
                                       
                              Field crop, typical
                                      220
                                     0.219
                                0.5 lb ai/acre
                                   350 acres
                                     0.558
                                      18
                                   0.000555
                                     7200
                                      18
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0954
                                      100
                                       
                                       
                                      100
                                       
                           Field crop, high-acreage
                                      220
                                     0.219
                                0.5 lb ai/acre
                                   350 acres
                                     0.558
                                      18
                                   0.000555
                                     7200
                                      18
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0954
                                      100
                                       
                                       
                                      99
              Mixing/Loading Liquids for Groundboom Applications
                    Roads, parking lots, etc. (pre-paving)
                                      220
                                     0.219
                               0.523 lb ai/acre
                                    5 acres
                                    0.00833
                                     1200
                                   0.0000083
                                    480000
                                     1200
                                       
                         Field-grown ornamental crops
                                      220
                                     0.219
                               0.368 lb ai/acre
                                   40 acres
                                     0.047
                                      210
                                   0.0000467
                                     86000
                                      210
                                       
                                      Sod
                                      220
                                     0.219
                               0.523 lb ai/acre
                                   80 acres
                                     0.133
                                      75
                                   0.000133
                                     30000
                                      75
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0228
                                      440
                                       
                                       
                                      430
                                       
                              Field crop, typical
                                      220
                                     0.219
                                0.5 lb ai/acre
                                   80 acres
                                     0.128
                                      78
                                    0.00876
                                     31000
                                      78
                                       
                                       
                                  37.6 (SL/G
                                       
                                       
                                       
                                    0.0217
                                      460
                                       
                                       
                                      450
                                       
                                  Fallow land
                                      220
                                     0.219
                                 1 lb ai/acre
                                   80 acres
                                     0.255
                                      39
                                   0.000254
                                     16000
                                      39
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0436
                                      230
                                       
                                       
                                      230
                                       
                           Field crop, high-acreage
                                      220
                                     0.219
                                0.5 lb ai/acre
                                   200 acres
                                     0.319
                                      31
                                   0.000317
                                     13000
                                      31
                                       
                                       
                                  37.6 (SL/G)
                                       
                                       
                                       
                                    0.0545
                                      180
                                       
                                       
                                      180
                                  Applicator
               Applying Sprays with Aerial Application Equipment
                    Roads, parking lots, etc. (pre-paving)
                                   2.08 (EC)
                                    0.0049
                                     (EC)
                               0.522 lb ai/acre
                                   60 acres
                                   0.000943
                                     11000
                                  0.00000222
                                    1800000
                                     11000
                                       
                         Field-grown ornamental crops
                                   2.08 (EC)
                                    0.0049
                                     (EC)
                               0.368 lb ai/acre
                                   40 acres
                                   0.0000443
                                     23000
                                  0.00000104
                                    380000
                                     23000
                                       
                                      Sod
                                   2.08 (EC)
                                    0.0049
                                     (EC)
                               0.522 lb ai/acre
                                   350 acres
                                    0.00551
                                     1800
                                   0.000013
                                    310000
                                     1800
                                       
                              Field crop, typical
                                   2.08 (EC)
                                    0.0049
                                     (EC)
                                0.50 lb ai/acre
                                   350 acres
                                    0.00528
                                     1900
                                   0.0000124
                                     32000
                                     1900
                                       
                                  Fallow land
                                   2.08 (EC)
                                    0.0049
                                     (EC)
                                 1 lb ai/acre
                                   350 acres
                                    0.0106
                                      940
                                   0.0000249
                                    160000
                                      930
                                       
                           Field crop, high-acreage
                                    No Data
                                    No Data
                                0.5 lb ai/acre
                                  1200 acres
                                    0.0181
                                      550
                                   0.0000426
                                     94000
                                      550
             Applying Sprays with Groundboom Application Equipment
                    Roads, parking lots, etc. (pre-paving)
                                     78.6
                                     0.34
                               0.523 lb ai/acre
                                    5 acres
                                    0.00299
                                     3300
                                   0.0000129
                                    310000
                                     3300
                                       
                         Field-grown ornamental crops
                                     78.6
                                     0.34
                               0.368 lb ai/acre
                                   40 acres
                                    0.0168
                                      600
                                   0.0000725
                                     55000
                                      590
                                       
                                      Sod
                                     78.6
                                     0.34
                               0.523 lb ai/acre
                                   80 acres
                                    0.0477
                                      210
                                   0.000206
                                     19000
                                      210
                                       
                              Field crop, typical
                                     78.6
                                     0.34
                                0.5 lb ai/acre
                                   80 acres
                                    0.0455
                                      220
                                   0.000197
                                     2000
                                      220
                                       
                                  Fallow land
                                     78.6
                                     0.34
                                 1 lb ai/acre
                                   80 acres
                                    0.0912
                                      110
                                   0.000394
                                     10000
                                      110
                                       
                           Field crop, high-acreage
                                     78.6
                                     0.34
                                0.5 lb ai/acre
                                   200 acres
                                     0.114
                                      88
                                   0.000493
                                     8100
                                      87
                                       
                                       
                                  16.1 (SL/G)
                                       
                                       
                                       
                                    0.0233
                                      430
                                       
                                       
                                      410
                                    Flagger
                   Flagging for Aerial Applications (Sprays)
                         Field-grown ornamental crops
                                      11
                                     0.35
                               0.368 lb ai/acre
                                   350 acres
                                    0.0203
                                      490
                                   0.0000654
                                     6100
                                      450
                                       
                                      Sod
                                      11
                                     0.35
                               0.522 lb ai/acre
                                   350 acres
                                    0.0291
                                      340
                                   0.000926
                                     4300
                                      320
                                       
                              Field crop, typical
                                      11
                                     0.35
                                0.5 lb ai/acre
                                   350 acres
                                     0.028
                                      360
                                   0.000888
                                     4500
                                      330
                                       
                                  Fallow land
                                      11
                                     0.35
                                 1 lb ai/acre
                                   350 acres
                                    0.0558
                                      180
                                    0.00178
                                     2200
                                      170
                                       
                           Field crop, high-acreage
                                      11
                                     0.35
                                0.5 lb ai/acre
                                   350 acres
                                     0.028
                                      360
                                   0.000888
                                     4500
                                      330
1	Based on the "Occupational Pesticide Handler Unit Exposure Surrogate Reference Table" (https://www.epa.gov/pesticide-science-and-assessing-pesticide-risks/occupational-pesticide-handler-exposure-data); Level of mitigation: Baseline unless shown otherwise. G = gloves, DL= double layer, EC = engineering control..
2	Based on registered labels.
3	Exposure Science Advisory Council Policy #9.1.
4	Dermal Dose = Dermal Unit Exposure (μg/lb ai) x Conversion Factor (0.001 mg/μg) x Application Rate (lb ai/acre or gal) x Area Treated or Amount Handled (A or gal/day)  / BW (69 kg).
5	Dermal MOE = Dermal POD (mg/kg/day) / Dermal Dose (mg/kg/day). Bold MOEs represent estimates of concern (LOC = 100).
6	Inhalation Dose = Inhalation Unit Exposure (μg/lb ai) x Conversion Factor (0.001 mg/μg) x Application Rate (lb ai/acre or gal) x Area Treated or Amount Handled (A or gal/day) / BW (69 kg).
7	Inhalation MOE = Inhalation POD (mg/kg/day) / Inhalation Dose (mg/kg/day). 
8	Total MOE = 1 / (1/Dermal MOE + 1/Inhalation MOE).

Occupational Handler Cancer Exposure and Risk Equations
Cancer risk estimates were calculated using a linear low-dose extrapolation approach in which a Lifetime Average Daily Dose (LADD) is first calculated and then compared with a Q1* that has been calculated for bromoxynil based on dose response data in the appropriate toxicology study (Q1* = 0.103 (mg/kg/day)[-1]).  Absorbed average daily dose (ADD) levels were used as the basis for calculating the LADD values.  Dermal and inhalation ADD values were first added together to obtain combined ADD values.  LADD values were then calculated and compared to the Q1* to obtain cancer risk estimates.  The algorithms used to estimate the LADD and cancer risk for occupational handlers can be found in Appendix B.

Days per Year of Exposure: To assess cancer risk, it is assumed that private growers would be exposed 10 days per year and commercial applicators would be exposed 30 days per year.  The term "private grower" means that the grower or one of the workers would apply the pesticides to land owned or operated by the grower.  Commercial applicators means the applicators are completing multiple applications for multiple clients.

Years per Lifetime of Exposure: It is assumed that handlers would be exposed for 35 years out of a 78 year lifespan.

Lifetime Expectancy: Life expectancy values are from the Exposure Factors Handbook 2011 Edition Table 18-1 (U.S. EPA, 2011).  The table shows that the overall life expectancy is 78 years based on life expectancy data from 2007.  In 2007, the average life expectancy for males was 75 years and 80 years for females.  Based on the available data, the recommended value for use in cancer risk assessments is 78 years. 

Summary of Occupational Handler Cancer Exposure and Risk Estimates
Occupational cancer risks were estimated for both private/farmer and contract/commercial handlers.  Cancer risks at baseline (single layer, no gloves, no respirator) range from 6E-07 to 4E-04 for private/farmer and 2E[-06] to 1E[-03] contract/commercial handlers. With the addition of lable recommended PPE , dermal and inhalation protection (double layer, gloves, P10 respirator), cancer risks range from 9E[-08] to 5E[-05] for private/farmer and 3E[-07] to 1E[-04] or contract/commercial handlers  

A summary of occupational cancer risks as estimated at all levels of personal protection and with use of engineering controls is presented in Tables 8.1.2 and 8.1.3.  Table 8.1.2 presents cancer risks for private/farmer handlers and Table 8.1.3 presents risks for contract/commercial handlers.  

Table 8.1.2.  Bromoxynil Occupational Handler Cancer Risk Estimates  -  Private/Farmer
                               Exposure Scenario
                                Crop or Target
                                 App. Rate[1]
                                Area Treated[2]
                                 (units/ day)
                               Private/Farmer[3]

                                SL/No G + No-R
                                  SL/G + No-R
                                  DL/G + No-R
                               SL/No G + PF10 R
                                 SL/G + PF10 R
                                 DL/G + PF10 R
                               SL/No G + PF50 R
                                 SL/G + PF50 R
                                 DL/G + PF50 R
                                      EC
                                 Mixer/Loader
                Mixing/Loading Liquids for Aerial Applications
                    Roads, parking lots, etc. (pre-paving)
                               0.522 lb ai/acre
                                   60 acres
                                     2E-05
                                     3E-06
                                     3E-06
                                     2E-05
                                     3E-06
                                     2E-06
                                     2E-05
                                     3E-06
                                     2E-06
                                     8E-07
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                  40 acres 
                                     9E-06
                                     2E-06
                                     1E-06
                                     9E-06
                                     1E-06
                                     1E-06
                                     9E-06
                                     1E-06
                                     1E-06
                                       
                                     4E-07
                                       
                                       
                                      Sod
                               0.522 lb ai/acre
                                   350 acres
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     4E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     4E-06
                                       
                                  Fallow land
                                1.0 lb ai/acre
                                   350 acres
                                     2E-04
                                     4E-05
                                     3E-05
                                     2E-04
                                     4E-05
                                     3E-05
                                     2E-04
                                     4E-05
                                     3E-05
                                     9E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                  1200 acres
                                     4E-04
                                     6E-05
                                     5E-05
                                     4E-04
                                     6E-05
                                     5E-05
                                     4E-04
                                     6E-05
                                     5E-05
                                     1E-05
              Mixing/Loading Liquids for Chemigation Applications
                                       
                                      Sod
                               0.500 lb ai/acre
                                   350 acres
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     4E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     4E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   350 acres
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     1E-04
                                     2E-05
                                     1E-05
                                     4E-06
              Mixing/Loading Liquids for Groundboom Applications
                    Roads, parking lots, etc. (pre-paving)
                               0.523 lb ai/acre
                                    5 acres
                                     2E-06
                                     3E-07
                                     2E-07
                                     2E-06
                                     3E-07
                                     2E-07
                                     2E-06
                                     3E-07
                                     2E-07
                                     6E-08
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                     9E-06
                                     2E-06
                                     1E-06
                                     9E-06
                                     1E-06
                                     1E-06
                                     9E-06
                                     1E-06
                                     1E-06
                                     4E-07
                                       
                                      Sod
                               0.523 lb ai/acre
                                   80 acres
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     1E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   80 acres
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     1E-06
                                       
                                  Fallow land
                                 1 lb ai/acre
                                   80 acres
                                     5E-05
                                     8E-06
                                     7E-06
                                     5E-05
                                     8E-06
                                     6E-06
                                     5E-05
                                     8E-06
                                     6E-06
                                     2E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   200 acres
                                     6E-05
                                     1E-05
                                     8E-06
                                     6E-05
                                     1E-05
                                     8E-06
                                     6E-05
                                     1E-05
                                     8E-06
                                     2E-06
                                  Applicator
               Applying Sprays with Aerial Application Equipment
                    Roads, parking lots, etc. (pre-paving)
                               0.522 lb ai/acre
                                   60 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     2E-07
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     8E-08
                                       
                                      Sod
                               0.522 lb ai/acre
                                   350 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     1E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     1E-06
                                       
                                       
                                  Fallow land
                                 1 lb ai/acre
                                   350 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     2E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                  1200 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     3E-06
             Applying Sprays with Groundboom Application Equipment
                    Roads, parking lots, etc. (pre-paving)
                               0.523 lb ai/acre
                                    5 acres
                                     6E-07
                                     1E-07
                                     1E-07
                                     6E-07
                                     1E-07
                                     9E-08
                                     6E-07
                                     1E-07
                                     9E-08
                                     4E-08
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                     3E-06
                                     7E-07
                                     6E-07
                                     3E-06
                                     6E-07
                                     5E-07
                                     3E-06
                                     6E-07
                                     5E-07
                                     2E-07
                                       
                                      Sod
                               0.523 lb ai/acre
                                   80 acres
                                     9E-06
                                     2E-06
                                     2E-06
                                     9E-06
                                     2E-06
                                     1E-06
                                     9E-06
                                     2E-06
                                     1E-06
                                     6E-07
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   80 acres
                                     9E-06
                                     2E-06
                                     2E-06
                                     8E-06
                                     2E-06
                                     1E-06
                                     8E-06
                                     2E-06
                                     1E-06
                                     6E-07
                                       
                                  Fallow land
                                 1 lb ai/acre
                                   80 acres
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     3E-06
                                     3E-06
                                     1E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   200 acres
                                     2E-05
                                     5E-06
                                     4E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     2E-05
                                     4E-06
                                     3E-06
                                     1E-06
                                    Flagger
                   Flagging for Aerial Applications (Sprays)
                                  Fallow land
                                 1 lb ai/acre
                                   350 acres
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                    No Data
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   350 acres
                                     5E-06
                                     5E-06
                                     4E-06
                                     4E-06
                                     4E-06
                                     4E-06
                                     4E-06
                                     4E-06
                                     4E-06
                                    No Data
                                       
                                      Sod
                               0.522 lb ai/acre
                                   350 acres
                                     6E-06
                                     7E-06
                                     6E-06
                                     6E-06
                                     6E-06
                                     5E-06
                                     5E-06
                                     6E-06
                                     5E-06
                                    No Data
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                     6E-06
                                     7E-06
                                     6E-06
                                     5E-06
                                     6E-06
                                     5E-06
                                     5E-06
                                     6E-06
                                     5E-06
                                    No Data
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   350 acres
                                     6E-06
                                     7E-06
                                     6E-06
                                     5E-06
                                     6E-06
                                     5E-06
                                     5E-06
                                     6E-06
                                     5E-06
                                    No Data
1	Based on registered labels.
2	Exposure Science Advisory Council Policy #9.1.
3	Cancer risk estimates = Total LADD x Q1[*], where Q1[*] = 0.103 (mg/kg/day)[-1]

Table 8.1.3.  Bromoxynil Occupational Handler Cancer Risk Estimates  -  Contract/Commercial Handler
                               Exposure Scenario
                                Crop or Target
                                 App. Rate[1]
                                Area Treated[2]
                                 (units/ day)
                        Contract/Commercial Handler[3]

                                SL/No G + No-R
                                  SL/G + No-R
                                  DL/G + No-R
                               SL/No G + PF10 R
                                 SL/G + PF10 R
                                 DL/G + PF10 R
                               SL/No G + PF50 R
                                 SL/G + PF50 R
                                 DL/G + PF50 R
                                      EC
                                 Mixer/Loader
                Mixing/Loading Liquids for Aerial Applications
                    Roads, parking lots, etc. (pre-paving)
                               0.522 lb ai/acre
                                   60 acres
                                     6E-05
                                     1E-05
                                     8E-06
                                     6E-05
                                     1E-05
                                     7E-06
                                     6E-05
                                     1E-05
                                     7E-06
                                     2E-06
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                     3E-05
                                     5E-06
                                     4E-06
                                     3E-05
                                     4E-06
                                     3E-06
                                     3E-05
                                     4E-06
                                     3E-06
                                    1E-06 
                                       
                                      Sod
                               0.522 lb ai/acre
                                   350 acres
                                     3E-04
                                     6E-05
                                     4E-05
                                     3E-04
                                     6E-05
                                     4E-05
                                     3E-04
                                     6E-05
                                     4E-05
                                     1E-05
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                     3E-04
                                     6E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     1E-05
                                       
                                  Fallow land
                                1.0 lb ai/acre
                                   350 acres
                                     6E-04
                                     1E-04
                                     9E-05
                                     6E-04
                                     1E-04
                                     8E-05
                                     6E-04
                                     1E-04
                                     8E-05
                                     3E-05
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                  1200 acres
                                     1E-03
                                     2E-04
                                     1E-04
                                     1E-03
                                     2E-04
                                     1E-04
                                     1E-03
                                     2E-04
                                     1E-04
                                     4E-05
              Mixing/Loading Liquids for Chemigation Applications
                                       
                                      Sod
                               0.500 lb ai/acre
                                   350 acres
                                     3E-04
                                     6E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     1E-05
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                     3E-04
                                     6E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     1E-05
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   350 acres
                                     3E-04
                                     6E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     3E-04
                                     5E-05
                                     4E-05
                                     1E-05
              Mixing/Loading Liquids for Groundboom Applications
                    Roads, parking lots, etc. (pre-paving)
                               0.523 lb ai/acre
                                    5 acres
                                     5E-06
                                     8E-07
                                     6E-07
                                     5E-06
                                     8E-07
                                     6E-07
                                     5E-06
                                     8E-07
                                     6E-07
                                     2E-07
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                     3E-05
                                     5E-06
                                     4E-06
                                     3E-05
                                     4E-06
                                     3E-06
                                     3E-05
                                     4E-06
                                     3E-06
                                     1E-06
                                       
                                      Sod
                               0.523 lb ai/acre
                                   80 acres
                                     7E-05
                                     1E-05
                                     1E-05
                                     7E-05
                                     1E-05
                                     1E-05
                                     7E-05
                                     1E-05
                                     1E-05
                                     3E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   80 acres
                                     7E-05
                                     1E-05
                                     1E-05
                                     7E-05
                                     1E-05
                                     9E-06
                                     7E-05
                                     1E-05
                                     9E-06
                                     3E-06
                                       
                                  Fallow land
                                 1 lb ai/acre
                                   80 acres
                                     1E-04
                                     3E-05
                                     2E-05
                                     1E-04
                                     2E-05
                                     2E-05
                                     1E-04
                                     2E-05
                                     2E-05
                                     6E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   200 acres
                                     2E-04
                                     3E-05
                                     2E-05
                                     2E-04
                                     3E-05
                                     2E-05
                                     2E-04
                                     3E-05
                                     2E-05
                                     7E-06
                                  Applicator
               Applying Sprays with Aerial Application Equipment
                    Roads, parking lots, etc. (pre-paving)
                               0.522 lb ai/acre
                                   60 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     5E-07
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    3E-07 
                                       
                                      Sod
                               0.522 lb ai/acre
                                   350 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     3E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     3E-06
                                       
                                  Fallow land
                                 1 lb ai/acre
                                   350 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     6E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                  1200 acres
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                    No Data
                                     1E-05
             Applying Sprays with Groundboom Application Equipment
                    Roads, parking lots, etc. (pre-paving)
                               0.522 lb ai/acre
                                    5 acres
                                     2E-06
                                     4E-07
                                     3E-07
                                     2E-06
                                     3E-07
                                     3E-07
                                     2E-06
                                     3E-07
                                     3E-07
                                     1E-07
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                   40 acres
                                     1E-05
                                     2E-06
                                     2E-06
                                     9E-06
                                     2E-06
                                     2E-06
                                     9E-06
                                     2E-06
                                     1E-06
                                     6E-07
                                       
                                      Sod
                               0.523 lb ai/acre
                                   80 acres
                                     3E-05
                                     6E-06
                                     5E-06
                                     3E-05
                                     6E-06
                                     4E-06
                                     3E-05
                                     5E-06
                                     4E-06
                                     2E-06
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   80 acres
                                     3E-05
                                     6E-06
                                     5E-06
                                     3E-05
                                     5E-06
                                     4E-06
                                     3E-05
                                     5E-06
                                     4E-06
                                     2E-06
                                       
                                  Fallow land
                                 1 lb ai/acre
                                   80 acres
                                     5E-05
                                     1E-05
                                     9E-06
                                     5E-05
                                     1E-05
                                     8E-06
                                     5E-05
                                     1E-05
                                     8E-06
                                     3E-06
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   200 acres
                                     7E-05
                                     1E-05
                                     1E-05
                                     6E-05
                                     1E-05
                                     1E-05
                                     6E-05
                                     1E-05
                                     1E-05
                                     4E-06
                                    Flagger
                   Flagging for Aerial Applications (Sprays)
                                  Fallow land
                                 1 lb ai/acre
                                   350 acres
                                     4E-05
                                     4E-05
                                     4E-05
                                     3E-05
                                     3E-05
                                     3E-05
                                     3E-05
                                     3E-05
                                     3E-05
                                    No Data
                                       
                         Field-grown ornamental crops
                               0.368 lb ai/acre
                                  350 acres 
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                     1E-05
                                   No Data 
                                       
                                      Sod
                               0.522 lb ai/acre
                                   350 acres
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                    No Data
                                       
                              Field crop, typical
                                0.5 lb ai/acre
                                   350 acres
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                    No Data
                                       
                           Field crop, high-acreage
                               0.500 lb ai/acre
                                   350 acres
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                     2E-05
                                    No Data
1	Based on registered labels.
2	Exposure Science Advisory Council Policy #9.1.
3	Cancer risk estimates = Total LADD x Q1[*], where Q1[*] = 0.103 (mg/kg/day)[-1]

8.2 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 re-entry 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.

8.2.1 Occupational Post-application Inhalation Exposure/Risk Estimates

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, 2010 (http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPP-2009-0687-0037).  The Agency has evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent Volatilization Screening Analysis (https://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2014-0219).  During Registration Review, the Agency will utilize this analysis to determine if data (i.e., flux studies, route-specific inhalation toxicological studies) or further analysis is required for bromoxynil.

In addition, the Agency is continuing to evaluate the available post-application inhalation exposure data generated by the Agricultural Reentry Task Force.  Given these two efforts, the Agency will continue to identify the need for and, subsequently, the way to incorporate occupational post-application inhalation exposure into the Agency's risk assessments.

Although a quantitative occupational post-application inhalation exposure assessment was not performed, an inhalation exposure assessment was performed for occupational/commercial handlers.  Handler exposure resulting from application of pesticides outdoors is likely to result in higher exposure than post-application exposure.  Therefore, it is expected that these handler inhalation exposure estimates would be protective of most occupational post-application inhalation exposure scenarios.

8.2.2 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.

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 post-application workers will not apply the same chemical every day for more than a one-month time frame; however, there may be a large agribusiness and/or commercial applicators who may apply a product over a period of weeks (e.g., completing multiple applications for multiple clients within a region).  

Transfer Coefficients: It is the policy of HED to use the best available data to assess post-application 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 3" which, along with additional information about the ARTF data, can be found at the Agency website.  

Application Rate: The registered application rates for bromoxynil are listed in Table 4.1.

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

Dislodgeable Foliar Residues (DFR):  A chemical-specific DFR data set has been submitted for bromoxynil on sweet corn (MRID 49884502).  The study (D448515, S.Tadayon, 8/9/2018) has been reviewed by HED and was found to be acceptable for risk assessment.

The DFR study was conducted at three sites: Germansville, PA (NAFTA Region 1), Delavan, WI (NAFTA Region 5), and Sanger, CA (NAFTA Region 10).  One application of the test product (Bromoxynil 4 EC, an emulsifiable concentrate containing a nominal 27% bromoxynil heptanoate and 28% bromoxynil octanoate) was made to corn foliage at a target application rate of 0.5 lb/A total bromoxynil, corresponding to 0.34 lb ai/A bromoxynil heptanoate and 0.35 lb ai/A bromoxynil octanoate.  The foliar broadcast spray applications were made using tractor mounted sprayers or CO2 backpack and spray volumes of 16-19 gallons of spray solution per acre (GPA). No adjuvants were used, with the exception of the Pennsylvania trial, which used a small amount of defoamer. Leaf samples were collected prior to and immediately after the application (when spray on the crop leaves had dried), and at 1, 2, 5, 7, 10, 13-14, 20, 27-28 and 33-35 days after treatment (DAT). At the California site, the 13-14DAT samples were not collected due to an oversight. At each sampling interval, three replicate DFR samples were collected from the treated plot.  Control samples were collected from each of the test sites prior to the application.  

At the Pennsylvania site, residues of bromoxynil heptanoate and bromoxynil octanoate were highest immediately after the application, declining to below the LOD by 5-7DAT; residues of bromoxynil phenol declined to below the LOD by 2DAT but showed a spike on 27-33DAT.  The average residue of total bromoxynil (and percent of application rate) was highest at 0DAT at 1.935 ug/cm[2] (35.1%), declined to 0.0087 ug/cm[2] (0.16%) by 7DAT, and increased to 0.0739 ug/cm[2] (1.34%) by 33DAT.  

At the Wisconsin site, residues of bromoxynil heptanoate and bromoxynil octanoate were highest immediately after the application, declining to below the LOD by 5DAT; residues of bromoxynil phenol declined to below the LOD by 1DAT but showed a spike on 28DAT.  The average residue of total bromoxynil (and percent of application rate) was highest at 0DAT at 1.065 ug/cm[2] (19.1%), declined to 0.0087 ug/cm[2] (0.16%) by 5DAT, and increased to 0.2014 ug/cm[2] (3.61%) by 28DAT.  

At the California site, residues of bromoxynil heptanoate and bromoxynil octanoate were highest immediately after the application, declining to below the LOD by 7DAT; residues of bromoxynil phenol declined to below the LOD by 1DAT but showed a spike on 27DAT.  The average residue of total bromoxynil (and percent of application rate) was highest at 0DAT at 0.7825 ug/cm[2] (13.7%), declined to 0.0087 ug/cm[2] (0.15%) by 7DAT, and increased to 0.0283 ug/cm[2] (0.50%) by 27DAT.  

The data and the results of the pseudo-first order statistical analysis are summarized below in Table 8.2.2.1. The predicted DAT-0 residue value of 1.924 ug/cm2 from the Pennsylvania site was used to estimate risks.

Table 8.2.2.1.  Review of Determination of Dislodgeable Foliar Residues on Sweet Corn Foliage Treated with Bromoxynil (MRID 49884502)
Statistic
                                 Pennsylvania
                                   Wisconsin
                                  California
Half-life (days)
                                      0.7
                                      0.4
                                      1.1
R[2]
                                    0.9998
                                    0.9299
                                    0.8363
Decay Constant (k)
                                    -1.034
                                    -1.639
                                    -0.617
Daily Dissipation (%)
                                      64
                                      81
                                      46
Actual Average 0DAT (ug/cm[2])
                                     1.935
                                     1.065
                                     0.783
Predicted Initial Residue (C0) (ug/cm[2])
                                     1.924
                                     1.381
                                     0.396
% of Application Rate calculated using Actual Average DFR on 0DAT
                                     35.09
                                     19.12
                                     13.74
Predicted % of Application Rate (%)
                                     34.86
                                     24.77
                                     6.95

Transferable Turf Residues (TTR):  A chemical-specific TTR data set has been submitted for bromoxynil (MRID 49884501).  The study (D448513, S.Tadayon, 8/9/2018) has been reviewed by HED and was found to be acceptable for risk assessment.

The TTR study was conducted at three sites: Chula, GA (NAFTA Region 2), Lenexa, KS (NAFTA Region 5), and Sanger, CA (NAFTA Region 10).  Two plots were established at each test site. One plot was designated at the irrigated test plot (TRTI) and the second as the non-irrigated test plot (TRTN).  One application of the test product (Bromoxynil 4 EC, an emulsifiable concentrate containing a nominal 27% bromoxynil heptanoate and 28% bromoxynil octanoate) was made to each plot at a target rate of 0.5 lb ai/A, corresponding to 0.35 lb bromoxynil heptanoate/A and 0.36 lb bromoxynil octanoate/A.  The test substance was applied using a tractor-mounted sprayer at each site.  Triplicate TTR samples were collected from the treated plots before and after each application (after the spray had dried) and at target times of  1-, 2-, 4-, 8-, 12-, 24-, 32-hours, and 2, 3, 4, 5, 6, and 7 days after treatment (DAT).  At the California site, the 5DAT samples were not collected due to an oversight. Control samples were collected from each of the test sites prior to the application.

At the Georgia site, the average total bromoxynil TTR from the non-irrigated plot was highest immediately following the application (0.0628 ug/cm[2]; 1.10% of application rate), the average TTR would decline and increase once before declining to 0.0021 ug/cm[2] (0.04% of application rate) at 1.3 DAT (31 hours after the application).  For the irrigated plot at the GA site, the average total bromoxynil TTR was highest immediately after the application was watered-in (0.0155 ug/cm[2]; 0.27% of the application rate) and declined to 0.0020 ug/cm[2] (0.03% of the application rate) 8 hours after the application. 

At the Kansas site, the average total bromoxynil TTR from the non-irrigated plot was highest 2 hours after the application (0.0468 ug/cm[2]; 0.83% of application rate), the average TTR would decline and increase once before declining to 0.0023 ug/cm[2] (0.04% of application rate) at 3DAT.  The average total bromoxynil TTR from the irrigated plot at the Kansas site was highest immediately after the application was watered-in (0.0233 ug/cm[2]; 0.42% of the application rate) and declined to 0.0018 ug/cm[2] (0.03% of the application rate) 12 hours after the application. 

At the California site, the average total bromoxynil TTR from the non-irrigated plot was highest immediately following the application (0.0360 ug/cm[2]; 0.63% of application rate), declining to 0.0025 ug/cm[2] (0.04% of application rate) at 2DAT.   The average total bromoxynil TTRs from the irrigated plot at the California site were all below the LOQ. 

The data and the results of the pseudo-first order statistical analysis are summarized below in Table 8.2.2.2. The predicted DAT-0 residue value of 0.041 ug/cm2 from the Georgia site (non-irrigated plot) was used to estimate risks.

Table 8.2.2.2.  Review of Determination of Transferable Turf Residues on Turf Treated with Bromoxynil (MRID 49884501)
Statistic
                                    Georgia
                                    Kansas
                                  California

                                     TRTN
                                     TRTI
                                     TRTN
                                     TRTI
                                     TRTN
                                    TRTI[1]
Half-life (days)
                                      0.4
                                      0.1
                                      0.7
                                      0.1
                                      0.5
                                      --
R[2]
                                     0.708
                                    0.9296
                                    0.8971
                                     0.921
                                     0.856
                                      --
Decay Constant (k)
                                    -1.927
                                    -7.008
                                    -0.995
                                    -4.733
                                    -1.282
                                      --
Daily Dissipation (%)
                                      85
                                      100
                                      63
                                      99
                                      72
                                      --
Actual Average 0DAT (ug/cm[2])
                                    0.0628
                                    0.0155
                                    0.0409
                                    0.0233
                                    0.0360
                                    0.0025
Predicted Initial Residue (C0) (ug/cm[2])
                                     0.041
                                     0.017
                                     0.036
                                     0.019
                                     0.023
                                      --
% of Application Rate calculated using Actual Average TTR on 0DAT
                                     1.10
                                     0.27
                                     0.73
                                     0.42
                                     0.63
                                     0.04
Predicted % of Application Rate (%)
                                     0.71
                                     0.30
                                     0.64
                                     0.35
                                     0.40
                                      --
[1] All average TTR values were below the LOQ; regression analysis not conducted.

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
Some dermal post-application exposure scenarios resulted in MOEs lower than the LOC (MOE >= 100) on the day of treatment (i.e., day 0) and are of concern. Risks were of concern (MOE < 100) were identified for the following scenarios: 

 Irrigating (hand set) alfalfa, grasses grown for seed, and mint up to 1 day after application at 0.5 lb ai/A
 Scouting barley and wheat on the day of treatment at 0.5 lb ai/A
 Scouting flax on the day of treatment at 0.25 lb ai/A
 Irrigating (hand set) corn (field and pop) up to 1 day after application at 0.5 lb ai/A
 Hand weeding onion (green and bulb) up to 1 day after application at 0.375 lb ai/A
 Hand weeding garlic up to 3 day after application at 0.5 lb ai/A.

Table 8.2.2.3. Occupational Post-application Non-Cancer Dermal Exposure and Risk Estimates for Bromoxynil.
                          Policy Crop Group Category
                                     Crops
                              Application Rate1 
                                   (lb ai/A)
                   Maximum Transfer Coefficient2 (cm[2]/hr)
                           Activities for MaximumTC
                                     DAT 
                             (Day After Treatment)
                           DFR Residue[3] (ug/cm[2])
                               Dose4 (mg/kg-day)
                                    MOE[5]
                        Field / row crop, low / medium
                     Alfalfa, Grasses Grown for seed, Mint
                                      0.5
                                     1900
                             Irrigation (hand set)
                                       0
                                     1.96
                                     0.431
                                      23
                                       
                                       
                                       
                                       
                                       
                                       1
                                     0.70
                                     0.153
                                      65
                                       
                                       
                                       
                                       
                                       
                                       2
                                     0.25
                                     0.054
                                      180
                                       
                     Barley, Wheat, spring, Wheat, winter
                                      0.5
                                     1100
                                   Scouting
                                       0
                                     1.96
                                     0.249
                                      40
                                       
                                       
                                       
                                       
                                       
                                       1
                                     0.70
                                     0.089
                                      110
                                       
                                     Flax
                                     0.25
                                     1100
                                   Scouting
                                       0
                                     0.98
                                     0.125
                                      80
                                       
                                       
                                       
                                       
                                       
                                       1
                                     0.35
                                     0.044
                                      230
                            Field / row crop, tall
                            Corn, field; Corn, pop
                                      0.5
                                     1900
                             Irrigation (hand set)
                                       0
                                     1.96
                                     0.431
                                      23
                                       
                                       
                                       
                                       
                                       
                                       1
                                     0.70
                                     0.153
                                      65
                                       
                                       
                                       
                                       
                                       
                                       2
                                     0.25
                                     0.054
                                      180
                                       
                                Sorghum, grain
                                      0.5
                                      210
                                   Scouting
                                       0
                                     1.96
                                     0.048
                                      210
                                  Turf / sod
                                      Sod
                                     0.523
                                     6700
            Maintenance;  Harvesting, Slab; Transplanting/Planting
                                       0
                                     0.042
                                     0.032
                                      310
                               Vegetable, "root"
                                       
                           Onion, bulb; Onion, green
                                     0.375
                                     4200
                                 Hand weeding
                                       0
                                     1.47
                                     0.714
                                      14
                                       
                                       
                                       
                                       
                                       
                                       1
                                     0.52
                                     0.254
                                      39
                                       
                                       
                                       
                                       
                                       
                                       2
                                     0.19
                                     0.090
                                      110
                                       
                                    Garlic
                                      0.5
                                     4200
                                 Hand weeding
                                       0
                                     1.96
                                     0.952
                                      11
                                       
                                       
                                       
                                       
                                       
                                       1
                                     0.70
                                     0.339
                                      30
                                       
                                       
                                       
                                       
                                       
                                       2
                                     0.25
                                     0.120
                                      83
                                       
                                       
                                       
                                       
                                       
                                       3
                                     0.09
                                     0.043
                                      220
1 Application rates are the maximum application rates determined from EPA registered labels for bromoxynil.
2 Transfer Coefficient and Post Application Activities from EPA's Occupational Pesticide Re-entry Exposure Calculator  -  Revised March 2017.
3	DFR Data source: MRID 49884502 (Sweet corn-PA site): Day 0 concentration = 1.924 ug/cm[2]; Study application rate = 0.492 lb ai/A 
	TTR Data source: MRID 49884501 (Non-irrigated turf-GA site): Day 0 concentration = 0.041 ug/cm[2]; Study application rate = 0.51 lb ai/A
4	Daily Dermal Dose = [DFR (ug/cm[2]) x Transfer Coefficient x 0.001 mg/ug x 8 hrs/day ]  BW (69 kg).
5	MOE = POD (mg/kg/day) / Daily Dermal Dose.  

Restricted Entry Interval

Bromoxynil is classified as Toxicity Category III via the dermal route and Toxicity Category IV for skin irritation potential.  It is not a skin sensitizer.  Short- and intermediate-term post-application risk estimates were not a concern on day 0 (12 hours following application) for most activities.  However, there were risk estimates of concern related to irrigating (hand set) alfalfa, grasses grown for seed, mint, and corn, and hand weeding onion (green and bulb) for up to 1 day after application
               
Occupational Post-application Cancer Dermal Exposure and Risk Equations
As was done for occupational handlers, post-application cancer risk estimates were calculated using a linear low-dose extrapolation approach in which a LADD is first calculated and then compared with a Q1* that has been calculated for bromoxynil based on dose response data in the appropriate toxicology study (Q1* = 0.103 (mg/kg/day)[-1]).  The algorithms used to estimate the LADD and cancer risk for occupational workers can be found in Appendix B.

Days per Year of Exposure: HED assumes that post-application workers would be exposed at a frequency of 30 days per year. 
  
Years per Lifetime of Exposure:  HED assumes that post-application workers would be exposed for 35 years out of a 78 year lifespan.

Lifetime Expectancy:  Based on available data from EPA's Exposure Factors Handbook 2011 Edition, the recommended lifespan for use in cancer risk assessments is 78 years.  Life expectancy values are derived from the Exposure Factors Handbook 2011 Edition Table 18-1 (U.S. EPA, 2011).  The table shows that the overall life expectancy is 78 years based on life expectancy data from 2007.  In 2007, the average life expectancy for males was 75 years and 80 years for females.  

Occupational Post-application Cancer Dermal Risk Estimates
A summary of post-application cancer risks is presented in Table 8.2.2.4.  Cancer risks based on a 30-day average dose range from 7E-07 to 3E-05.

Table 8.2.2.4.  Occupational Post-application Cancer Dermal Exposure and Risk Estimates for Bromoxynil.
                          Policy Crop Group Category
                                     Crops
                              Application Rate1 
                                   (lb ai/A)
                   Maximum Transfer Coefficient2 (cm[2]/hr)
                           Activities for MaximumTC
                               Yearly Frequency
                                  (days/year)
                            Lifetime Average Dose3 
                     Using 30-day Average Dose (mg/kg-day)
                                Cancer Risk[4] 
                        Field / row crop, low / medium
                     Alfalfa, Grasses Grown for seed, Mint
                                      0.5
                                     1900
                             Irrigation (hand set)
                                      30
                                    0.0001
                                     1E-05
                                       
                     Barley, Wheat, spring, Wheat, winter
                                      0.5
                                     1100
                                   Scouting
                                      30
                                    0.0001
                                     7E-06
                                       
                                     Flax
                                     0.25
                                     1100
                                   Scouting
                                      30
                                    0.00003
                                     3E-06
                            Field / row crop, tall
                            Corn, field; Corn, pop
                                      0.5
                                     1900
                             Irrigation (hand set)
                                      30
                                    0.0001
                                     1E-05
                                       
                                Sorghum, grain
                                      0.5
                                      210
                                   Scouting
                                      30
                                    0.00001
                                     1E-06
                                  Turf / sod
                                      Sod
                                     0.523
                                     6700
            Maintenance;  Harvesting, Slab; Transplanting/Planting
                                      30
                                    0.00001
                                     7E-07
                               Vegetable, "root"
                           Onion, bulb; Onion, green
                                     0.375
                                     4200
                                 Hand weeding
                                      30
                                    0.0002
                                     2E-05
                                       
                                    Garlic
                                      0.5
                                       
                                       
                                       
                                    0.0003
                                     3E-05
  1 Application rates are the maximum application rates determined from EPA registered labels for bromoxynil.
  2 Transfer Coefficient and Post Application Activities from EPA's Occupational Pesticide Re-entry Exposure Calculator  -  Revised Jan 2017.
  3 Calculated using 30-day average dose.  Dermal LADD (mg/kg/day) = Dermal dose (mg/kg/day) x [Days per year of exposure (30 days/yr) / 365 days/year] x [Years per lifetime of exposure (35 yrs) /  Lifetime expectancy (78 yrs)].
  4 Cancer risk estimates = Dermal LADD x Q1*, where Q1* =0.103 (mg/kg/day)-1

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:

E=UE * AR * A * 0.001 mg/ug

where:

E	=	exposure  (mg ai/day),
UE	=	unit exposure (ug 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:

ADD=  E * AFBW

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:

MOE= PODADD

where:

MOE	=	margin of exposure: value used by HED to represent risk estimates (unitless),
POD	=	point of departure (mg/kg/day), and
ADD	=	average daily dose absorbed in a given scenario (mg ai/kg/day).

Occupational Non-cancer Post-application Algorithms

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

DFRt=AR *  F* (1-D)t*4.54E8uglb*2.47E-8Acm2

where:

DFRt	=	dislodgeable foliage residue on day "t" (ug/cm[2]),
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).

E=TC * DFR t * ET * 0.001mgug

where:
E	=	exposure  (mg ai/day),
TC 	=	transfer coefficient (cm[2]/hr),
DFRt	=	dislodgeable foliar residue on day "t" (ug/cm[2]), and
ET	=	exposure time (hours/day).
 
The daily doses are calculated using the following formula:

ADD=  E * AFBW

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:

MOE= PODADD

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).

Appendix B.  Summary of Occupational and Residential Cancer Algorithms

After the development of the ADD values, the next step required to calculate carcinogenic risk estimates is to amortize these values over the anticipated lifetime, which results in the LADD.  LADD values are calculated using the following equation:

LADD =  ADD *  Days per Year of Exposure365 Days per Year *  Years per Lifetime of ExposureLifetime Expectancy

where:

LADD	=	absorbed dose over a lifetime (mg ai/kg/day),
ADD	=	average daily dose absorbed in a given scenario (mg 
		ai/kg/day),
Days per Year of Exposure	=	annual frequency of an application by an individual 
		(days/year),
Years per Lifetime of Exposure	=	amount of a lifetime that an individual would be 
		expected to use pesticides (years), and
Lifetime Expectancy	= 	average life expectancy of an individual (years).

Cancer risk estimate calculations are completed by comparing the LADD values calculated above to the Q1* for the chemical.  Cancer risk estimates are calculated using the following equation:

Total Cancer Risk Estimate =  Dermal LADD + Inhalation LADD *  Q1*

where:

Cancer Risk Estimate	=	probability of incidence of cancer cases over a lifetime (unitless),
Dermal LADD	=	absorbed dose from dermal exposure over a lifetime (mg ai/kg/day),
Inhalation LADD	=	absorbed dose from inhalation exposure over a lifetime (mg ai/kg/day), and
Q1*	=	quantitative dose response factor used for linear, low-dose response cancer risk estimate calculations (mg/kg/day)[-1].

Appendix C.  Summary of Spray Drift Algorithms

Modified TTR Equation to Account for Spray Drift
The equation presented below, should be used to evaluate potential risks from spray drift. This equation is similar to the standard TTR equation, except that an additional term has been included (DF or Drift Fraction) that provides an adjustment for the amount of drift that moves into and deposits in a non-target area, such as a lawn. This equation applies to situations where TTR data are not available.

                   TTR = AR * DF * F * (1-D)[t] * CF2 * CF3
where:
	TTR 	  =	turf transferable residue (ug/cm[2])
      DF	=	drift fraction of spray drift that deposits on lawns (unitless)
	AR	=	application rate (lbs ai/ft[2] or lb ai/acre)
	F	=	fraction of ai as transferable residue following application (unitless)	D	=	fraction of residue that dissipates daily (unitless)
      T	=	post-application day on which exposure is being assessed (Day 0 in this SOP)
      CF2	=	weight unit conversion factor (4.54 x 10[8] ug/lb)
      CF3	=	area unit conversion factor (1.08 x 10[-3] ft[2]/ cm[2] or 2.47 x 10[-8] acre/cm[2])

If chemical specific TTR data are available, the residue on Day 0 is used after it is adjusted based on the ratio of the applicable application rate for risk assessment (i.e., based on the crop of concern) and the application rate for the TTR study followed by an additional adjustment for the drift fraction factor as illustrated above.

Drift Fraction Values
The spray drift fraction (DF) values for selected aerial, groundboom, and airblast application scenarios, based on average deposition values at each distance of interest, are shown in the tables below (Tables B-1, -2, -3).
 
Table C-1. Average Drift Fractions for a 50' Wide Lawn Starting at Various Distances Downwind From a Field Treated Using Aerial Equipment.
                                 Droplet Size+
              Distance Downwind From Treated Field (feet)

                                       0
                                      10
                                      25
                                      50
                                      75
  100
 125
  150
  200
  250
  300
Fine to Medium*
 0.257
 0.209
 0.169
 0.129
 0.098
 0.076
 0.063
 0.054
 0.041
 0.034
 0.028
Medium to Coarse*
 0.211
 0.156
 0.115
 0.082
 0.058
 0.044
 0.035
 0.029
 0.021
 0.016
 0.013
Coarse to Very Coarse*
 0.183
 0.124
 0.082
 0.053
 0.037
 0.028
 0.022
 0.018
 0.013
 0.010
 0.008
Very Fine to Fine*
 0.373
 0.340
 0.305
 0.262
 0.226
 0.197
 0.175
 0.155
 0.127
 0.108
 0.095
AT401, M, 10 mph,
34% SD
 0.234
 0.183
 0.142
 0.105
 0.078
 0.060
 0.049
 0.042
 0.032
 0.026
 0.021
WASP, M, 10 mph,
34% SD
 0.218
 0.171
 0.129
 0.086
 0.063
 0.049
 0.040
 0.034
 0.026
 0.021
 0.018
AT401, C, 10 mph,
25% SD
 0.198
 0.141
 0.099
 0.067
 0.047
 0.036
 0.029
 0.024
 0.017
 0.013
 0.011
WASP, C, 10 mph,
25% SD
 0.171
 0.121
 0.084
 0.053
 0.038
 0.028
 0.023
 0.018
 0.013
 0.010
 0.009
AT401, VC, 10 mph,
20% SD
 0.175
 0.115
 0.072
 0.044
 0.031
 0.023
 0.018
 0.014
 0.010
 0.008
 0.006
WASP, VC, 10 mph,
20% SD
 0.138
 0.088
 0.057
 0.036
 0.025
 0.019
 0.014
 0.012
 0.008
 0.007
 0.006
 *Information is based on the Tier 1 option in the AgDrift model. The fine to medium spray quality is used in this SOP as the basis for the screening level assessment. These are all based on fixed wing aircraft.
 +For further options the AT401 is the representative fixed wing aircraft and the Wasp is the representative helicopter. SD = swath displacement. SD values for non-Tier I options computed using AgDrift automated adjustment option.

 Spray Quality Summaries: Fine to Medium (F2M): Dv0.5 = 255 uM; Medium (M): Dv0.5 = 294 uM; Medium to Coarse (M2C): Dv0.5 = 341 uM; Coarse (C) Dv0.5 = 385 uM; Coarse to Very Coarse (C2VC): Dv0.5 = 439 uM;Very Coarse (VC): Dv0.5 = 478 uM & Very Fine to Fine (VF2F): Dv0.5 = 137 uM  -  only to be used with labeling justification

Table C-2. Average Drift Fractions for a 50' Wide Lawn Starting at Various Distances Downwind From a Field Treated Using Ground Equipment.

 Boom Height
                                  Droplet Size
                  Distance Downwind From Treated Field (feet)

                                       0
                                      10
                                      25
                                      50
                                      75
  100
  125
  150
  200
  250
  300

  High
     Very Fine to Fine

 0.187

 0.093

 0.056

 0.035

 0.025

 0.020

 0.017

 0.014

 0.011

 0.008

 0.007

  Low
     Very Fine to Fine
 0.085
 0.032
 0.020
 0.013
 0.010
 0.008
 0.007
 0.006
 0.005
 0.004
 0.003

  High
 Fine to Medium/Coarse
 0.049
 0.019
 0.013
 0.009
 0.007
 0.006
 0.005
 0.005
 0.004
 0.003
 0.003

  Low
 Fine to Medium/Coarse
 0.033
 0.012
 0.008
 0.006
 0.005
 0.004
 0.003
 0.003
 0.002
 0.002
 0.002
 Low Boom 0.508 m (20 in), High Boom 1.27 m (50 in)
 Fine to Medium/Coarse (F2M/C): Avg. Droplet size (Dv0.5) = 341 uM

Table C-3. Average Drift Fractions for a 50' Wide Lawn Starting at Various Distances Downwind From a Field Treated Using Orchard Blast Equipment.

  Crop Canopy
                  Distance Downwind From Treated Field (feet)

                                       0
                                      10
                                      25
                                      50
                                      75
  100
  125
  150
  200
  250
  300
  Sparse
 0.1435
 0.0834
 0.0443
 0.0200
 0.0110
 0.0068
 0.0045
 0.0032
 0.0018
 0.0011
 0.0008
  Normal
 0.0030
 0.0020
 0.0013
 0.0009
 0.0006
 0.0005
 0.0004
 0.0003
 0.0003
 0.0002
 0.0002
   Dense
 0.0422
 0.0279
 0.0175
 0.0100
 0.0067
 0.0049
 0.0039
 0.0032
 0.0023
 0.0018
 0.0015
  Vineyard
 0.0080
 0.0041
 0.0022
 0.0012
 0.0008
 0.0006
 0.0005
 0.0004
 0.0003
 0.0002
 0.0002
 Sparse (Young, Dormant): This composite orchard combines small grapefruit and dormant apple orchards. Normal (Stone and Pome Fruit, Vineyard): This composite orchard combines grape and orchards.
 Dense (Citrus, Tall Trees): This composite orchard combines almond, orange, grapefruit, small grapefruit (mist blower) and pecan orchards.
 Vineyard: This composite curve combines grape air blast sprayer applications and may not apply to other application equipment.
 Note: AgDrift also contains an "Orchard" scenario which is a composite of results from all tree canopy types. Since it is a composite it has not been included.

Post-application Dermal Exposure Algorithm -- Physical Activities on Turf
Exposure resulting from contacting previously treated turf while performing physical activities is calculated as shown below:
E=TTRtxCF1xTCxET
where:
E	=	exposure (mg/day);
TTRt	=	turf transferable residue on day t (ug/cm2);
CF1	=	weight unit conversion factor (0.001 mg/ug);
	TC	=	transfer coefficient (cm2/hr); and
	ET	=	exposure time (hr/day).

Dermal absorbed doses are calculated as:
D=ExAFBW
where: 
	D	=	dose (mg/kg-day);
	E	=	exposure (mg/day);
	AF	=	absorption factor (dermal); and
	BW	=	body weight (kg).

 Table C-4. Turf (Physical Activities)  -  Recommended Point Estimates for Post-Application Dermal Exposure Factors
   Algorithm Notation
                                   Exposure Factor (units)
  Point Estimate(s)
                                      AR
                               Application rate
                    (mass active ingredient per unit area)
                                  See Table 4.1.

                                       F
  Fraction of AR as TTR following application (if chemical-specific data are unavailable)
      L/WP/WDG
                                     0.01

                                   Granules

                                     0.002

                                      FD
     Daily residue dissipation (if chemical-specific data are unavailable)
                                  (fraction)
      L/WP/WDG
                                      0.1

                                   Granules

                                      0.1

                                      TC
                         Transfer Coefficient (cm2/hr)
 L/WP/WDG
                                    Adults
                                    180,000

  Children 1 < 2 years old
                                    49,000

  Granules
                                    Adults
                                    200,000

  Children 1 < 2 years old
                                    54,000
                                      ET
     Exposure Time (hours per day)
                                    Adults
                                      1.5

  Children 1 < 2 years old
                                      1.5
                                      BW
        Body Weight (kg)
                                    Adults
                                      69

  Children 1 < 2 years old
                                      11

Post-application Hand-to-Mouth Exposure Algorithm -- Physical Activities on Turf
Exposure from hand-to-mouth activity is calculated as follows (based on the algorithm utilized in the SHEDS-Multimedia model):

  E = [HR * (FM * SAH) * (ET * N_Replen) * (1- (1- SE)[(Freq_HtM/N-Replen)])]
where:
	E		=	exposure (mg/day);
      HR		=	hand residue loading (mg/cm[2]);
	FM		=	fraction hand surface area mouthed / event (fraction/event);
	SAH		=	typical surface area of one hand (cm[2]);
	ET		=	exposure time (hr/day);
	N_Replen	=	number of replenishment intervals per hour (intervals/hour);
	SE		=	saliva extraction factor (i.e., mouthing removal efficiency); and
	Freq_HtM	=	number of hand-to-mouth contact events per hour (events/hour).

and
		
where:
	HR		=	hand residue loading (mg/cm[2]);
	Faihands		=	fraction ai on hands compared to total surface residue from dermal
                  transfer coefficient study (unitless);
	DE		=	dermal exposure (mg); and
      SAH		=	typical surface area of one hand (cm[2]).

Dose, normalized to body weight, is calculated as:
	 	
where:
      D	= dose (mg/kg-day);
      E	= exposure (mg/day); and
      BW	= body weight (kg).
      
Table C-5. Turf (Physical Activities)  -  Inputs for Residential Post-application Hand-to-Mouth Exposure 
                              Algorithm Notation
                            Exposure Factor (units)
                               Point Estimate(s)
                                   Faihands
   Fraction of ai on hands from dermal transfer coefficient study (unitless)
                              Liquid formulations
                                     0.06
                                       
                                       
                             Granular formulations
                                     0.027
                                      DE
                             Dermal exposure (mg)
                                  Calculated
                                      SAH
     Typical surface area of one hand (cm[2]), children 1 < 2 years old
                                      150
                                      AR
            Application rate (mass active ingredient per unit area)
                                      0.5
                                      HR
                   Residue available on the hands (mg/cm[2])
                      Calculated via (DE * Faihands)/SAH
                                      FM
              Fraction hand surface area mouthed (fraction/event)
                                     0.127
                                   N_Replen
                Replenishment intervals per hour (intervals/hr)
                                       4
                                      ET
                            Exposure time (hrs/day)
                                      1.5
                                      SE
                      Saliva extraction factor (unitless)
                                     0.48
                                   Freq_HtM
                   Hand-to-mouth events per hour (events/hr)
                                     13.9
                                      BW
                               Body Weight (kg)
                          Children 1 < 2 years old
                                      11

Appendix D.  Summary of Directions for Agricultural Occupational Uses of Bromoxynil

Table 4.1. Summary of Directions for Agricultural Occupational Uses of Bromoxynil
Use Site
Formulation
Application Target
Application Type
Application Equipment
Maximum Application Rate
PPE
Labels
User Directions and Limitations
Alfalfa
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer
0.375 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78; 9779-346
REI = 24 hrs

Foliage/ Plant
Broadcast
Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78; 9779-346
REI = 24 hrs
Barley
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
1381-249; 1381-258; 264-1075; 264-1168; 264-540; 264-690; 34704-1052; 34704-996; 42750-103; 42750-48; 42750-52; 62719-557; 71368-77; 71368-78; 9779-346
REI = 24 hrs
Corn, Field 
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant headgear
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78; 71368-93; 9779-346

Max. application rate: 0.5 lb ai/A/year

REI = 24 hrs

Foliage/ Plant
Spot Treatment

Groundboom sprayer 
0.499 lb ai/A

●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
62719-557

REI = 24 hrs
Corn, Pop
Liquid
Foliage/ Plant
Broadcast

Air, Groundboom sprayer, Chemigation 
0.50 lb ai/A

●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 42750-50; 71368-78; 71368-93; 9779-346

Max. application rate: 0.5 lb ai/A/year

REI = 24 hrs
Fallow land
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer
1.00 lb ai/A

●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
71368-93

Max. application rate: 1.00 lb ai/A/year

REI = 24 hrs

Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.523 lb ai/A

●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
1381-258

Max. application rate: 0.522 lb ai/A/year

REI = 24 hrs
Flax
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer
0.25 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
264-540; 264-690; 34704-1052; 42750-103; 42750-48; 42750-52; 71368-78; 9779-346

REI = 24 hrs
Garlic
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78; 9779-346

REI = 24 hrs
Grasses Grown for Seed
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
264-540; 264-690; 34704-1052; 42750-48; 42750-52; 62719-557; 71368-77; 71368-78; 9779-346
REI = 12 and 24 hrs

Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.499 lb ai/A

●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
62719-557

REI = 12 and 24 hrs
Grass Forage/ Fodder/ Hay
Liquid
Foliage/ Plant
Broadcast
Groundboom sprayer
0.205 lb ai/A
●  Chem. resistant gloves
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-1023
Max. application rate: 0.41 lb ai/A/year

REI = 24 hrs
Grass/Turf
Liquid
Foliage/ Plant
Broadcast
Air
0.522 lb ai/A
●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
1381-258
Max. application rate: 0.522 lb ai/A/year

Foliage/ Plant
Broadcast/
Spot Treatment
Groundboom sprayer
0.523 lb ai/A
●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
1381-258
Max. application rate: 0.522 lb ai/A/year

Foliage/ Plant
Broadcast
Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
264-540; 264-690; 34704-1052; 42750-103; 42750-52; 42750-48; 71368-77; 9779-346
REI = 12, 24, 288, and 624 hrs
Mint/ Peppermint/ Spearmint
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer
0.375 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48, 71368-78; 9779-346
REI = 24 hrs

Foliage/ Plant
Broadcast
Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78; 9779-346
REI = 24 hrs
Oats
Liquid
Foliage/ Plant
Broadcast/
Spot treatment
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
1381-249; 264-540; 264-690; 34704-1052; 42750-103; 42750-48; 42750-52; 62719-557; 71368-77; 71368-78; 9779-346
REI = 24 hrs

Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.499 lb ai/A
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
62719-557
REI = 24 hrs
Onion

Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.375 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78; 9779-346
REI = 24 hrs
Premises/ Areas
Liquid
Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.523 lb ai/A
●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
1381-258
Max. application rate: 0.522 lb ai/A/year

Foliage/ Plant
Broadcast
Helicopter
0.522 lb ai/A
●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
1381-258
Max. application rate: 0.522 lb ai/A/year

Foliage/ Plant
Broadcast
Air
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
42750-48; 9779-346; 264-540; 71368-78

Rye

Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
264-540; 264-690; 34704-1052; 34704-996; 42750-103; 42750-48; 42750-52; 71368-77; 71368-78; 9779-346
REI = 24 hrs
Shrubs/ Bushes/ Vines

Liquid
Foliage/ Plant
Broadcast, Directed
Air, Groundboom sprayer
0.368 lb ai/A
●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
CA050012
REI = 12 hrs
Sorghum
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
9779-346; 264-540; 42750-48; 71368-78
REI = 24 hrs

Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.382 lb ai/A

●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
62719-557

REI = 24 hrs
Sudangrass
Liquid
Foliage/ Plant
Broadcast, 
Spot Treatment
Air, Groundboom sprayer
0.499 lb ai/A

●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
62719-557

REI = 24 hrs

Foliage/ Plant
Broadcast
Chemigation
0.50 lb ai/A

●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 71368-78

REI = 24 hrs
Triticale
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
264-540; 42750-48; 62719-557; 71368-78; 9779-346
REI = 24 hrs

Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.499 lb ai/A
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
62719-557
REI = 24 hrs
Wheat
Liquid
Foliage/ Plant
Broadcast
Air, Groundboom sprayer, Chemigation
0.50 lb ai/A
●  Chem. resistant apron
●  Chem. resistant footwear
●  Chem. resistant gloves
●  Chem. resistant headgear
●  Coverall / Double-layer
●  Enclosed Cab (App. Equipment)
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
●  Respirator, NIOSH filtering half face
1381-249; 1381-258; 264-540; 264-690; 34704-1052; 34704-996; 42750-103; 42750-48; 42750-52; 62719-557; 71368-77; 71368-78; 9779-346
REI = 24 hrs

Foliage/ Plant
Spot Treatment
Groundboom sprayer
0.499 lb ai/A

●  Chem. resistant apron
●  Chem. resistant gloves
●  Coverall / Double-layer
●  Long-sleeve shirt, long pants, shoes/socks
●  Protective Eyewear
1381-258; 62719-557

REI = 24 hrs