Date:

SUBJECT: UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C

. 20460

July 1

, 20 14 OFFICE OF CHEMICAL S AFETY
AND POLLU T ION PREVE NT ION

Dimethenamid

- P (DMTA-P)

. Occupational and R esident ial Exposure

Assessment for a Propos ed New Use on Cotton S ub group 20C

.

PC Co de: 120051

Decis ion No.: 482296

Petition No. : 3F8197 DP Barco de: 0418 11 7 Regi s tr at ion No.: 7969 -1 56 Regula t ory Action: Amended Section 3 Registration

Case No.: 7223 Risk Assessment Type: ORE

TX R No. : N o t App li cable

MRID No

. : 47901302 CAS No.: 16 35 1 5- 14

- 8

40 C FR: § 180.464

From:

Th ro ugh:

To :

Introductio n Ivan D

. N i eves,

# hemi**~** /, ) __:_.-.-
Health Effects Division

# (750**9PUAss ~s** **ment** Br anch IV

ElissaReaves,Chief 

# c/"_**~** Health E ffect s D i v ision (7509 P )/Risk

# ~anch I V

and 

# vO**~** 

# -\tv**~c.~** Margari ta Co ll a nt es, ExpoSAC R eviewer # 1**\~** 

### Q 1 Alexandra LaMay, Ex poSAC Revi ewe r # 2 

# ;j ':;2:!. 

# J:f /t.-, /

Exposure Science Advisory C ommitte e (ExpoSAC) 

### /HEf) 

# ?

E. Kraf t:J K. Davis (RM 25)

He rbicide Br anc h Registration Division (7505P)

The Re gistration Division (RD) request e d that the H ealth Effects Di vision (HE D) conduct an

occu pa t i o n al expos ur e and ri s k ass e ssmen t for the proposed new use of dimethenamid

- P in/on

Co tton. Fo r purposes of p erfo rming an agg regat e assess ment

, a revised residenti al ex posur e

assessment is als o provided for reg i stered turf and gar den u ses.

It i s H E D policy to use th e be s t available da t a to assess ex p osure. Several sourc es of gen er i c data were u s ed in thi s assessme nt as s urro ga te data in the ab se n ce of chemica l- spec ific da ta

, including: Pesticid e Hand l ers Ex posure Database Vers ion 1.1 ( PHED 1. 1 ); th e Agr i cu ltur al

Page I of36Handler Exposure Task Force (AHETF) database; the Outdoor Residential Exposure Task Force (ORETF) database; the Agricultural Reentry Task Force (ARTF) database; the Residential SOPs (Lawns/Turf and Garden/Trees), other registrant-submitted exposure monitoring studies (MRID 47901302); published literature study, etc]. 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 6/19/2014.

Page 2 of36Page 3 of 36 Table of Contents

1.0 Executive Summary

................................ ................................ ................................ ............. 4
2.0 Data Deficiencies and Requirements

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

................................ ................................ ................................ ....... 6
4.0 Use Profile

................................ ................................ ................................ ........................... 9
5.0 Residential Exposure and Risk Estimates

................................ ................................ ............ 9
5.1 Residential Handler Exposure/Risk Estimates

................................ ............................... 10
5.2 Residential Post

- application Exposure/Risk Estimates

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

................................ ...... 14
5.4 Spray Drift

................................ ................................ ................................ ...................... 15
5.5 Residential Bystander Post

- Application Inhalation Exposure

................................ ....... 15
6.0 Occupational Exposur e and Risk Estimates

................................ ................................ ...... 16
6.1 Occupational Handler Exposure/Risk Estimates

................................ ............................ 16
6.2 Occupational Post

- application Exposure/Risk Estimates

................................ .............. 20
6.2.1 Occupational Post

- application Inhalation Exposure/Risk Estimates

...................... 20
6.2.2 Occupational Post

- ap plication Dermal Exposure/Risk Estimates

.......................... 20 Appendix A. Summary of Occupational and Residential Non

- cancer Algorithms

..................... 24Page 4 of 36

1.0 Executive Summary

The active ingredient (ai) S

- dimethenamid [( S )

- 2

- chloro

- N

- [( 1

- methyl

- 2

- methoxy)ethyl]

- N

- (2,4

- dimethyl

- thien

- 3

- yl) acetamide; commo n name dimethenamid

- P is the herbicidally active isomer
of R/S

- dimethenamid. DMTA

- P is a chloroacetamide herbicide (protein synthesis inhibitor) used for pre

- emergent control or suppression of annual broadleaf and grass weeds in a variety of field
and vegetable crops

. BASF Corporation Crop Protection (hereafter refer r ed to as BASF) is requesting an amendment to the Section 3 registration for Outlook® Herbicide (EPA Registration Number 7969

- 156), a 6.0 lb/gal emulsifiable concentrate (EC) formulation of
dimethenamid

- P, to add preplant, preemergence and early postemergence broadcast applications to members of cottonseed subgroup 20C.

Proposed Use Profile
Based on the application rate and label information, occupational exposure is expected to occur
for short

- and intermediate

- term durations. Chronic exposure is not expected for the proposed
use pattern. Potential routes of exposure include both dermal and inhalation. P replant and preemergence applications may be made at up to 0.5 lb ai/A and early postemergence applications may be made at up to 1.0 lb ai/A. Sequential applications of a preplant or preemergence application followed by an early postemergence application at least 14

- days after the initial application may be made at up to 1.5 lb ai/A/season. No preharvest interval (PHI) is specified but the last application may be made two weeks after the R1 initial bloom stage. The
restricted ent ry interval for the proposed use is 12 hours. The proposed label requires baseline clothing plus chemical

- resistant gloves , and protective eyewear as personal protective equipment (PPE). Applications for the proposed are expected to be made with an aircraft, groundboom truck, chemigation, and/or handheld equipment.

Non

- occupat ional (residential) exposures are not anticipated from the proposed new use, although residential exposure is expected for currently registered products. The existing residential uses have been reassessed in this document to reflect updates to HED’s 2012

Residential SOPs 1 along with policy changes for body weight assumptions.

Hazard C haracterization The existing toxicological database is primarily comprised of studies conducted with [RS]

- dimethenamid (50:50, S : R ). However, bridging studies indicate th at the dimethenamid toxicology database is adequate for the risk assessment of DMTA

- P . The acute toxicity data indicate that [S]

- dimethenamid

- P is in Category II via the oral route of exposure, and Category III for exposure via the dermal and inhalation r outes. It is moderately irritating to the eye (Category III) and slightly irritating to the skin (Category IV). DMTA

- P is a mild skin
sensitizer. The s hort

- and intermediate

- term point of departure (POD ) for dermal e xposure (300 mg/kg/day) was based on decreased body weight on a 21 day dermal study in rabbits

. The

inh alation and incidental oral toxicity endpoint ( 10 mg/kg/day) was selected from a subchronic and chronic oral toxicity study in dogs based on decreased body weight in females, increased
rela tive to body liver weight in both sexes, increased periportal cytoplasmic vacuolation in liver in both sexes, and dilation of liver sinusoids in females

. A s ubchr onic inhalation to xicity study is not available, however, t he Hazard and Science Policy Council (HASPOC), using a weight of the

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

- exposure

- sop.htmlPage 5 of 36

evidence (WOE) approach, concluded that a subchronic inhalation study is not required for
dimethenamid

- P at this time (TXR# 0056993)

.

Combining Exposures/Risk Estimates
Dermal and inhala tion exposures to workers were not aggregated because the toxicity endpoints for these exposure routes are not based on common toxicity effects in/of the liver. Dermal effects (body weight gain) were considered to be non

- specific.

Summary of Residential Exposure and Risk Estimates All existing r esidential exposures have been reassessed to reflect updates to HED’s 2012 Residential SOPs along with policy changes for body weight assumptions

. N o registered products result ed in residential handler or post

- app lication risk estimates of concern. All risk estimates are greater than HED’s Level of Concern ( LOC ) of 100 and therefore not of concern

. (Dermal M argins O f E xposure (MOEs) range d from 250 to 5,3 00,000 ; Inhala tion MOEs range from 7,700 to 1,5 00,000 ; and p ost

- application MOEs range from 310 to 200 ,000 )

.

Summary of Occupational Exposure and Risk Estimates

O ccupational handler dermal and inhalation exposure and risk assessment are not of concern (i.e. all MOEs ≥ 100) at baseline mitigation (no PPE), with one exception. T he dermal exposure scenario of mixing and loading a liquid formulation of DMTA

- P for aerial applications resulted
in an MOE of 92

. However, w ith the use of additional PPE (i.e., gloves) the risk estimate was mitigated to an MOE of 54 0. Derm al MOEs ranged from 92 to 9,100 . Inhalation MOEs ranged from 3,100 to 140,000

. Note that only engineering control (enclosed cockpit) data are available to assess risks to handlers operating aircrafts . Short

- and intermediate

- term post

- application risk

est imates were not a concern on day 0 (12 hours following application) for all post

- application
activities (MOEs ranged from 5,100 to 15,000)

.

Restricted Entry Interval (REI) Under 40 CFR 156.208 (c) (2) (iii), ai’s classified as Toxicity Category III or I V for acute dermal, eye irritation and primary skin irritation are assigned a 12

- hour REI. Therefore, the label required REI of 12 hours is adequate to protect agricultural workers from post

- application
exposures to DMTA

- P

.

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

- cancer occupational post

- application inhalation exposure assessment was not performed for DMTA

- P at this time. If new policies or procedures are put into place, the Agency may revisit the need fo r a quantitative occupational
post

- application inhalation exposure assessment for DMTA

- P

.

Human Studies Review This risk assessment relies in part on data from studies in which adult human subjects were intentionally exposed to a pesticide or other chemical. These data, which include studies from PHED 1.1; the AHETF database; the Outdoor Residential Exposure Task Force (ORETF) database; the ARTF database; the Residential SOPs ( Lawns/Turf and Garden/Trees); other registrant

- submitted exposure monitor ing studies ( MRID 47901302 ); published literature study, etc], 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 mayPage 6 of 36

hav e 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

.

2.0 Data Deficiencies and Requirements

None.

3 .0 Hazard Characterization

Acute Toxicity
The acute toxicity for DMTA

- P is summarized in Table 3.1

.

Table 3.1 . Acute Toxicity Profile for Dimethenamid

- P [PC 120051]

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

870.1100 Acute oral/rats [Sprague

Dawley] 44097603

(1996) LD 50 = 429 mg/kg males

LD 50 = 531 mg/kg females

LD 50 =480 mg/kg both sexes II

870.1200 Acute dermal/rabbits

[NZW] 44332234

(1996) LD 50 = >2000 mg/kg III

870.1300 Acute inhalation

[Sprague Dawley] 44332235 (1996) LC 50 = 2.2 mg/L III

870.2400 Acute eye irritation

[NZW] 44332238

(1996) Minimally irritating III

870.2500 Acute dermal irritation

[NZW] 44332239

(1996) Minimally irritating IV

870.2600 Skin sensitization

[Guinea Pigs] 44097604 Mild skin sensitizer Sensitizer

Toxicological PODs Used for Risk Assessment The primary target organ for dimethenamid (enriched (P) and racemic ( RS ) mixtures) is the liver and is displayed throughout the database and in all species tested. Chronic studies performed
with [RS]

- dimethenamid in the rat, mouse and dog showed decreases in body weight and food efficiency as accompanying effects over time. At higher dose levels, liver pathology, stomach hyperplasia, and some indication s of kidney effects were noted . In some of the studies , liver enzymes coupled with incre ased cholesterol levels a t high doses result ed in liver pathology. In

, two 21

- day dermal toxicity studies in rabbits were conducted on [RS]

- dimethenamid and in one
of those stud ies minor skin irritation was observed at all doses tested and a d ecrease in bo dy weight gain was also seen at the lowest effect level. Together these studies are considered co

critical for dermal short and intermediate

- term exposures. A summary of the toxicological endpoints and doses chosen for the relevant exposure scenarios for human risk assessment are
found in Table 3. 2.

T he POD for s hort

- and intermediate

- term dermal occupational and non

- occupational exposures
is 300 mg/kg/day based on decreased body weight gain at the LOAEL of 500 mg/kg/day per co

-

2 http://www.epa.gov/pest icides/science/handler

- exposure

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

- app

- exposure

- data.htmlPage 7 of 36

critical 21

- day dermal t oxicity studies in rabbits (MRID 41662414, MRID 41951301). Since the
short

- and intermediate

- term dermal POD was based on a route

- specific toxicity study, no absorption factor was necessary to estimate exposure. It was also noted that the effects seen ar e considered non

- specific.

T he POD for short

- and intermediate

- term inhalation occupational and non

- occupational

exposures is 10 mg/kg/day based on decreased body weight in females, increased relative to body liver weight in both sexes, increased peripo rtal cytoplasmic vacuolation in liver in both sexes, and dilation of liver sinusoids in females at the LOAEL of 33.6 mg/kg/day per co

- critical (MRID 41615902

, MRID 41615903 )

. No inhalation absorption data are available, therefore, toxicity by the inhalation route is considered to be equivalent to the estimated toxicity by the oral route of exposure. The same POD (10 mg/kg/day) was selected for incidental oral exposure in
children

. A s ubchr onic inhalation toxicity study is not available. However, the Hazard and Science Policy Council (HASPOC), using a weight of the evidence (WOE) approach, concluded that a subchronic inhalation study is not required for dimethenamid

- P at this time (TXR# 0056993)

Dermal and inhalation exposures to workers were not aggregated because the toxicity endpoints for these exposure routes are not based on common toxicity effects in/of the liver. Dermal effects (body weight gain) were considered to be non

- specific.

The standard body weight for the general population (80 kg ) was used for all exposure scenarios covered in this risk assessment since the endpoints selected were not developmental and/or fetal
effects.

Cla ssification of Carcinogenic Potential The Carcinogenicity Peer Review of dimethenamid on 23/MAR/1995 (TXR# 0 12143) and 15/JUN/1992 (TXR# 012831) stated that the weight of evidence classification was Group C

- possible human carcinogen

. The chronic point of departure (cPOD) is protective for potential carcinogenic effects. This decision was based on a statistic ally significant increasing trend for liver cell tumors (benign and malignant combined) in male rats. Dimethenamid has shown positive results in some genotoxicity tests and is structurally related to other chloroacetanilide carcinogens (i.e., acetochlor, metolachlor). An acceptable study in mice showed no dose related

tumors. [ Note : The cancer classification has not been updated based on the EPA’s 2005 Guidelines for Carcinogen Risk Assessment . However, any reclassification would not affect the conclusion that the cPOD is protective for carcinogenic effects and would therefore not affect the risk assessment.]

Food Quality Protection Act (FQPA) and Uncertainty Factors
HED’s level of concern for risks (i.e., target level for MOE ) is defined by the uncertainty factors that are applied to the assessment. HED applies a factor of 10X to account for interspecies extrapolation to humans from the animal test species and another fac tor of 10X to account for
intra

- species sensitivity. The FQPA safety factor was previously reduced to 1X based on toxicological considerations by the HIARC (12/2/03; TXR # 0052260)

. RAB I V toxicologists
reviewed the data available for DMTA

- P for the curre nt action and supported the previous decision to reduce the FQPA safety factor. The total uncertainty factor that has been applied toPage 8 of 36

occupational and residential risk assessments is 100 X for short

- and intermediate

- term dermal and inhalation exposures.

Table 3. 2. Summary of Toxicological Doses and Endpoints for Dimethenamid

- P

Exposure/Scenario Point of Departure Uncertainty/FQPA
SF RfD, PAD,

LOC for Risk
Assessment Study and Toxicological Effects

Acute Dietary (General Population, including
Infants and Children) NOAEL = 200 UF A = 10x

UF H =10x FQPA SF= 1x aRfD = 2.0

aPAD = 2.0 L OAEL = 600 mg/kg from ACN study based on

lacrimation, salivation, irregular and accelerated respiration, slight tremors, reduced exploration, unsteady gait, significantly reduced rearing (females) and strongly constricted pupils (males)

Incidental Oral Short

Term (1

- 30 days) and
Intermediate

- Term (1

- 6 months) NOAEL= 10 mg/kg/day UF A = 10 X

UF H = 10 X LOC for MOE

= 100 Subchronic/chronic oral dog studies (MRIDs

41615902 & 41615903)

NOAEL is from the chronic dog study Chronic dog LOAEL = 48.7 mg/kg/day Subchronic NOAEL = 4.72 mg/kg day
Subchronic LOAEL = 33.6 mg/kg/day from the subchronic dog study based on decreased b ody weight in females, increased relative to body
liver weight in both sexes, increased periportal cytoplasmic vacuolation in liver in both sexes,
and dilation of liver sinusoids in females.

Inhalation Short

- Term (1

- 30 days) and
Intermediate

- Term (1

- 6 months) NOAEL= 10 mg/kg/day UF A = 10 X

UF H = 10 X LOC for MOE

= 100 Subchronic/chronic oral dog studies (MRIDs

41615902 & 41615903)

NOAEL is from the chronic dog study Chronic dog LOAEL = 48.7 mg/kg/day Subchronic NOAEL = 4.72 mg/kg day
Subchronic LOAEL = 33.6 mg/kg/day from the subchronic dog study based on decreased b ody weight in females, increased relative to body liver weight in both sexes, increased periportal cytoplasmic vacuolation in liver in both sexes,

Dermal Short

- Term (1

- 30 days) and
Intermediate

- Term (1

- 6 months) NOAEL= 300 mg/kg/day UF A = 10X

UF H =10X LOC for MOE

= 100 21 Day dermal rabbit study (MRIDs

41662414/419513010) LOAEL = 500 mg/kg/day based on decreased body weight gain only (non

- specific) Cancer (oral, dermal, inhalation) “C” Possible human carcinogen. (No Q 1 *). The cRfD is con sidered protective of the cancer effects.

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

- response data and used to mark the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures; NOAEL = no observed adverse effect level; LOAEL = lowest observed adverse effect level; UF = uncertainty factor; UF A = extrapolation from animal to human (interspecies); UF H = potential variation in sensitivity amo ng members of the human population (intraspecies); FQPA SF = FQPA Safety Factor; PAD = population adjusted dose (a = acute, c = chronic); RfD = reference dose; MOE = margin of exposure; LOC = level of concernPage 9 of 36

4 .0 Use Profile

BASF has submitted a Section B of the petition proposing an amendment to the Section 3 registration for Outlook® Herbicide (EPA Registration Number 7969

- 156), a 6.0 lb/gal emulsifiable concentrate (EC) formulation of dimethenamid

- P, to add preplant, preemergence and early post emergence applications to members of cottonseed subgroup 20C. Preplant surface or preemergence applications may be made at up to 0.47 lb ai/A and an early postemergence application may be made at up to 0.98 lb ai/A. Sequential applications of a preplant or preemergence application followed by an early postemergence application at least 14

- days after the initial application may be made at up to 1.45 lb ai/A/season. No preharvest interval (PHI) is specified but the last application may be made two weeks af ter the R1 initial bloom stage. Section B of the petition is draft supplemental labeling to the current Outlook® Herbicide label (EPA Registration Number 7969

- 156). The use directions of the draft supplemental labeling to the subject end

- use product unde r consideration provided in Section B are summarized in Table

4.1.

T able 4.1. Summary of Directions for Use of Dimethenamid

- P.

Appl. Timing, Type, and Equip. Formulation

[EPA Reg. No.] Max. Appl.

Rate (lb ai/A) Max.

No. Appl.

per Season Max.
Seasonal Appl.

Rate (lb ai/A) PHI

(days) Use Directions and

Limitations

Cottonseed subgroup 20C: C otton.

Preplant surface,

preemergence and/or
postemergence foliar broadcast. Ground, aerial or chemigation 6.0 lb/gal

EC [7969

- 156] 0.47

preplant
surface or

preemergence 1

1.45 Not Specified May be applied as single

application or in sequential applications (preplant or preemergence followed by postemergence). Sequential applications must be separated by at least 14 days. No PHI is specified; however, postemergence applications may be made from first true leaf stage to
the mid

- bloom stage (i.e.,
two weeks after R1 initial bloom stage). 0.98
postemergence 1

PHI = preharvest interval.

5 .0 Residential Exposure and Risk Estimates

There are no proposed residential uses at this time; however, there are existing residential uses that have been reassessed in this document to reflect updates to HED’s 2012 Residential SOPs 3 along with policy changes for body weight assumptions. The revision of residential exposures will impact the human health aggregate risk assessment for d imethenamid

- P

.

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

- exposure

- sop.htmlPage 10 of 36

DMTA

- P is registered for residen tial use on turfgrass, ornamentals , and tree plantatio ns , and is
formulated as an emulsifiable concentrate (EC) and granul e (G). The currently registered end

use products (EPs) available for residential use include:

1. Tower Herbicide EC (EPA Reg. No. 7969

- 239; 63.9% DMTA

- P ), ,
2. Freehand 1.75G Herbicide (EPA Re g. No. 7969

- 273; 0.75% DMTA

- P ), and

3. Freehand CA 1.75G Herbicide (EPA Reg. No. 7969

- 358; 0.75% DMTA

- P )

.

BASF Corporation is the registrant of all three products.

5 .1 Residential Handler Exposure/Risk Estimates

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

The quantitative exposure/risk assessment developed for residential handlers is based on various exposure scenarios that invol ve mixing/loading/applying various formulations wit h manually pressurized handguns

, hose

- end sprayer s , backpack sprayers, push

- type rotary spreaders and belly grinders

.

Residential Handler Non

- Cancer Exposure and Risk Estimate Equations The algorithms used to estimate exposure and dose for residential handlers can be found in Appendix A and/or the 2012 Residential SOPs 4

.

Com bining Exposures/Risk Estimates Dermal and inhalation exposures to workers were not aggregated because the toxicity endpoints for these exposure routes are not based on common toxicity effects in/of the liver. Dermal effects (body weight gain) were considered to be non

- specific.

Summary of Residential Handler Non

- Cancer Exposure and Risk Estimates
Summaries of the sh ort

- term dermal and inhalation risk estimate s for residential handlers are
included in Table 5.1.1

. The maximum application rate for each exposure scenario is present ed as the worst case scenario. All risk estimates are greater than the LOC of 100 and th erefore not of concern ( Dermal MOEs range from 25 0 to 5,3 00 ,000 ; Inhalation MOEs range from 7,700 to 1,5 00,000 ).

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

- expos ure

- sop.htmlPage 11 of 36 Table 5.1.1. Residential Handler Non

- cancer Exposure and Risk Estimates for Dimethenamid

- P.

Exposure
Scenario Application

Equipment/

Method Dermal Unit

Exposure (mg/lb ai) Inhalation Unit

Exposure (mg/lb ai) Maximum

Application

Rate 1 Area Treated

or Amount Handled Daily 2 Dermal Inhalation

Dose (mg/kg/day) 3 MOE 4

(LOC=100) Dose

(mg/kg/day) 5 MOE 6

(LOC=100)

Liquid Formulation

Lawns/Turf Hose

- end

Sprayer 13.4 0.022 1.5 lb ai/acre 0.5 acres 0.13 2,400 0.00021 49,000

Manually

pressurized
handwand 63 0.018 0.15 lb ai/gal 5 gallons 0.59 510 0.00017 60,000

Backpack 130 0.14 1.2 250 0.0013 7,700

Gardens/Trees Sprinkler can

58 0.0014 0.15 lb ai/gal 5 gallons 0.54 550 0.000013 770,000

Hose

- end Sprayer 11 gallons 0.13 2,400 0.00021 49,000

Granular Formulation

Lawns/Turf Push

- type rotary

spreader 0.81 0.0026 1.5 lb ai/acre 0.5 acres 0.0076 40,000 0.000024 410,000

Belly grinder 360 0.039 3.4x10

- 5 lb ai/
ft 2 1,200 ft 2 0.19 1,600 0.000020 500,000

Gardens/Trees Hand Dispersal 160 0.38 3.4x10

- 5 lb ai/
ft 2 1,200 ft 2 0.083 3,600 0.00020 52,000

Shaker can / Cup 0.0045 0.00054 0.000057 5,300,000 0.0000067 1,500,000
Spoon 6.2 0.087 0.0032 94,000 0.000045 220,00

1 Based on registered residential uses for dimethenamid

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

- exposure

- sop.html ): Lawns/Turf ; and Gardens/Trees

3 Dermal Dose = Dermal Unit Exposure (mg/lb ai) × Application Rate (lb ai/ acre or gal or ft 2 ) × Area Treated or Amount Handled (A/day or gallons/day or
ft 2 /day) × Dermal Absorption Factor (100 %) ÷ Body Weight (80 kg).

4 Dermal MOE = Dermal NOAEL (mg/kg/day) ÷ Dermal Dose (mg/kg/day).
5 Inhalation Dose = Inhalation Unit Exposure (mg/lb ai) × Application Rate (lb ai/acre or gal or ft 2 ) × Area Treated or Amount Handled (A/day or gallons/day or ft 2 /day) ÷ Body Weight (80 kg).

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

7 Total MOE = NOAEL (mg/kg/day) ÷ (Dermal Dose + Inhalation Dose) OR Total MOE = 1 ÷ [(1 / Dermal MOE) + (1 /Inhalation MOE)].Page 12 of 36

5

. 2 Residential Post

- application Exposure/Risk Estimates

There is the potential for post

- application exposure for individuals exposed as a result of being in an environment that has been previously treated with dimethenamid

- P

. The quantitative exposure/risk assessment for residential post

- application exposures is based on the following
scenarios:

The scenarios, routes of exposure and lifestages of potential exposure include:

1. Physical activities on turf: adults (dermal) and children 1 to < 2 years old (dermal and incidental oral);

2. Mowing: adults (dermal) and children 11 to < 16 years old (dermal);

3. Golfing: adults (dermal) , children 11 to < 16 years old (dermal) , and children 6 to < 11 years old (dermal); and

4. Contact with Treated Gardens and Trees: adults (dermal) and children 6 to <11 years old (dermal).

The lifestages selected for each post

- application scenario are based on an analysis provided as an Appendix in the 2012 Residential SOPs 5

. While not the only lifestage potentially exposed for these post

- application scenarios, the lifestage that is include d in the quantitative assessment is health protective for the exposures and risk estimates for any other potentially exposed lifestage.

Residential Post

- application Exposure Data and Assumptions A series of assumptions and exposure factors served as the b asis for completing the residential
post

- application risk assessment . Each assumption and factor is detailed in the 2012 Residential

SOPs 5 : Lawns/ Turf, and Gardens and Trees

.

Furthermore, a chemical specific Transferable Turf Residue (TTR) Study was submitted by the registrant ( MRID# 47901302), reviewed by HED (D376733, I. Nieves, 3/16/11) and found to be acceptable for use in exposure and risk assessments. This study was designed to determine the transferable turf residue (TTR) of dimethenamid

- P dislodged from turf treated with an emulsifiable concentrate formulation containing 63.9% dimethenamid

- P as the active ingredient ( Tower® Herbicide ) a nd a spreadable granule formulation containing 0.75% dimethenamid

- P ( FreeHand® 1.75 G Herbicide ) at three locations in the United States (Florida, New Jersey, and California). Transferable residues were sampled using the Modified California Roller technique.

The TTR values used to quantify potential exposure risk by performing residential post

application activities on lawns/turf were taken from the aforementioned study. For liquid
formulations , the highest predicted dimethenamid

- P TTR level detected was 0.0312 μg/cm 2
(California site) . For granular formulations, s ince DMTA

- P TTR values were not detected above the LOQ at any sampling interval after application a TTR value of 0.00090 μg/cm 2, equivalent

to 1⁄2 the LOQ value ( 0.00179 μg/cm 2 ) is being used for human health exposure assessments.

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

- exposure

- sop.htmlPage 13 of 36

For p ost

- application dermal exposure resulting from contact with previously treated gardens and

trees , the default Dislodgeable Foliar Residue (DFR) calculation was done in the absence of
chemical

- specific data.

Residential Post

- application Non

- Cancer Exposure and Risk Equations The algorithms used to estimate residential post

- application exposure and dose can be found in Appendix A and/or the 2012 Residential SOPs 5

.

Combining Exposure and Risk Estimates HED combines risk estimates resulting from separate post

- appl ication exposure scenarios when it is likely they can occur simultaneously based on the use pattern and the behavior associated with the exposed population and when the toxicological effects are similar. However, the incidental oral scenarios (i.e., hand

- to

- mouth, object

- to

- mouth, soil ingestion, and granule ingestion) should be considered inter

- related and it is likely that they occur interspersed amongst each other across time. Combining all three of these scenarios would be overly

- conservative
because of the conservative nature of each individual assessment. Therefore, the hand

- to

- mouth
post

- application exposure scenario for children 1 to < 2 years old is considered a protective estimate of children’s exposure to pesticides used on turf.

Summary of Residential Post

- application Non

- Cancer Exposure and Risk Estimates
Table 5. 2.1 presents the post

- application MOE values calculated for adults and children af ter turf applications of DMTA

- P . HED considers this liquid formulation risk estimates for post

a pplication exposure to be protective of the granular product, because of its lower transferability properties compared to that observed for the liquid formulation, Tower Herbicide (0.64% transferability for the liquid compared to 0.005% for the granular). This phenomena can be observed in the TTR study ( MRID# 47901302) submitted by the registrant, BASF, where TTR values were not detected above the LOQ at any sampling interval for the granular formulation product . Post

- application non

- cancer risks do not exceed HED’s level of concern for any of the

scenarios assessed (MOEs range from 310 to 200,000; LOC = 100)

.

Table 5.2.1 DMTA

- P (Tower Herbicide EC) Residential Risk Estimates for Turf Post

- application Exposure.

Site Activity Route of Exposure TC

(cm 2 /hr) TTR (Study)

/DFR (Default) (μg/cm2 ) Exposure

Time (hrs/day) Short

- Term

Average Daily

Dose 2 (mg/kg/day) MOE 3

(LOC=100)

Adults Max single application rate: 1.5 lbs ai/A 1

Treated

Lawns High Contact Activities

Dermal 180,000

TTR (Lawns/Turf):
0. 0312 1.5 0.11 2,900

Mowing 5,500 1 0.0 0 2 1 140,000

Golf
Course
Turf Golfing 5,300 4 0.0 08 3 36,000

Gardens

High Contact Activities

(liquid and granular formulations) 8,400

DFR (Gardens/Trees):

4.2 2.2 0.96 310

Trees and
Retail
Plants 1,700 1 0.089 3,400

Indoor
Plants 220 1 0.011 26,000

ChildrenPage 14 of 36

Table 5.2.1 DMTA

- P (Tower Herbicide EC) Residential Risk Estimates for Turf Post

- application Exposure.

Site Activity Route of Exposure TC

(cm 2 /hr) TTR (Study)

/DFR (Default) (μg/cm2 ) Exposure

Time (hrs/day) Short

- Term

Average Daily

Dose 2 (mg/kg/day) MOE 3

(LOC=100)

Max single application rate: 1.5 lbs ai/A 1

Treated
Residential

Areas High Contact Activities (1<2 years)

Dermal 49,000

0. 0312 1.5 0.21 1,400

Mowing (11<16 years) 4,500 1 0.0 0 2 5 120,000

Golfing (6<11 years) 2,900 4 0. 0 1 1 27,000

Hand to Mouth Transfer of Pesticide Residue (1<2 years)

Oral N/A Hand Residue (mg/cm 2 ) 1.5 0.0 0 4 3 2 ,3 00

0.00 046

Object to Mouth Transfer of Pesticide Residue (1<2 years) Object Residue (mg/cm 2 ) 1.5 0.0 0 01 3 7 7 ,000

0.031

Incidental Ingestion of Soil with Pesticide Residue (1<2 years) Soil Residue (mg/cm 2 ) N/A 0.000051 200,000

11.17

Incidental Granule Ingestion (episodic) (1<2 years) Ingestion Rate (g/day; 0.8% ai) N/A 0.20 980

0.3

Gardens

High Contact Activities

(6<11 years) (liquid and granular formulations) Dermal 4,600

DFR (Gardens/Trees):

4.2 1.1 0.66 460

Trees and
Retail
Plants 930 0.5 0.061 5,000

Indoor
Plants 120 0.5 0.0078 38,000

1 Based on registered label s (Refer to Section 5 ).

2 Dose (mg/kg/day) equations provided in Appendix [ A ].
3 MOE = POD (mg/kg/day) ÷ Dose (mg/kg/day).

5

. 3 Residential Risk Estimates for Use in Aggregate Assessment

Table 5.3.1 reflects the residential exposure scenarios and associated risk estimates that are recommended for use in the aggregate assessment for DMTA

- P

.

 The recommended residential exposure for use in the adult aggregate assessment reflects
handler inhalation exposure from liquid applica tions to turf via bac kpack sprayer.

 The recommended residential exposure for use in the children 1<2 years old aggregate
assessment reflects incidental oral exposure from post

- application hand

- to

- mouth pesticide transfer from liquid application to resident ial turf.

Since it was determined that the dermal POD have no common toxicity effects with the incidental oral and/or inhalation PODs (same POD) the values recommended to be used for the
aggregate assessment are based on the worst

- case residential exposur e estimates via the inhalation (adult male) and oral (child 1<2 years old) routes. Only short

- term residential exposures are expected based on the Residential SOPs (2012). All residential handler and post

applicat ion exposure estimate resulted in MOEs gr eater than 100, and are not of concern.Page 15 of 36

Table 5.3.1. Recommendations for the Resident ial Exposures for the dimethenamid

- P Aggregate Assessment.

Lifestage Exposure Scenario Dose (mg/kg/day) 1 MOE 2

Dermal Inhalation Oral Total Dermal Inhalation Oral Total

Adult

Male Handler: Backpack

Sprayer application of liquid
formulation to turf N/A 0.0013 N/A 0.0013 N/A 7,700 N/A 7,700

Child (1<2 years old) Post

- a pplication: High

Contact Activities
From liquid application to
residential turf N/A N/A 0.0043 0.0043 N/A N/A 2,300 2,300

1 Dose = the highest dose for each applicable lifestage of all residential scenarios assessed

. Note: Only inhalation and oral exposure had common effects and therefore aggregated. Values were not presented for dermal exposure as they were not relevant for aggregate (i.e., no common effects)

. 2 MOE = the MOEs associated with the highest residential doses

. Note: Only inhalation and oral exposure had common effects and therefore aggregated. Values were not presented for dermal ex posure as they were not relevant for aggregate (i.e., no common effects)

.

5

. 4 Spray Drift

Spray drift is a potential source of exposure to those nearby pesticide applications. This is particularly the case with aerial application, but, to a lesser extent, spray drift can also be a potential source of exposure from the ground application method s (e.g., groundboom and airblast) employed for DMTA

- P

. 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 Sta te 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). 6 The Agency is also taking means to qualitatively and qualitatively address spra y drift as a potential source of exposure in risk assessments for pesticides through existing programs such as Ag Drift and chemical specific properties of pesticides. The potential for spray drift will be quantitatively evaluated for each pesticide durin g the Registration Review process which ensures that all uses for that pesticide will be considered concurrently.

5

. 5 Residential Bystander Post

- Application Inhalation Exposure

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

- application in halation exposure assessment was not performed for dimethenamid

- P at this time primarily because of the low
acute inhalation toxicity (Toxicity Category III ). However, volatilization of pesticides may be a source of post

- application inhalation exposure to individuals nearby pesticide applications. The Agency sought expert advice and input on issues related to volatilization of pesticides from its Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel (SAP) in December 2009, and rece ived the SAP’s final report on March 2, 2010 7

. The Agency is in the process of evaluating t e SAP report and may, as appropriate, develop policies and procedures to identify the need for and, subsequently, the way to incorporate post

- application inhalation exposure into the Agency's risk assessments. If new policies or procedures are developed, the Agency may revisit the need for a quantitative post

- application inhalation exposure assessment
for dimethenamid

- P

.

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

7 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.htmlPage 16 of 36

6 .0 Occupational Exposure and Risk Estimates

6 .1 Occupational Handler Exposure/Risk Estimates

HED uses the term handlers to describe those individuals who are involved in the pesticide application process. HED believes that there are distinct job functions or tasks related to applications and exposures can vary depending on the specifics of each t ask. Job requirements (amount of chemical used in each application), the kinds of equipment used, the target being treated, and the level of protection used by a handler can cause exposure levels to differ in a manner specific to each application event.

Based on the anticipated use patterns and current labeling, types of equipment and techniques that can potentially be used, occupational handler exposure is expected from the proposed uses. The quantitative exposure/risk assessment developed for occupat ional handlers is based on several scenarios which include mixing/loading/applying the liquid formulation of
dimethenamid

- P. The use profile is summarized in Section 4.0. Methods of application include aerial, chemigation, groundboom, and handheld equipm ent. Flagging for aerial use is also a potential source of wo rker exposure. Refer to Table 6 .1 .1 for a detailed list of each scenario.

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 : Refer to the proposed use pattern table in Section 4.0.

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, 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 8 ”, 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 9

.

Area Treated or Amount Handled : The area treated or amount handled is based on HED ExpoSAC P olicy No. 9.1. Refer to Table 6 .1 .1 for these assumptions for each scenario.

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

- term and exposures 30 day s 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 ag ricultural 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

8 Available: http://www.epa.gov/opp00001/science/handler

- exposure

- table.pdf

9 Available: http://www.epa.gov/pes ticides/science/handler

- exposure

- data.htmlPage 17 of 36

commercial applicators who may apply a product over a period of weeks (e.g., completing multiple applications for multiple clients within a region). For the proposed use on cotton subgroup 20C both short

- and intermediate

- term exposures are expected from occupational use.
Since the PODs for short

- and inte rmediate

- term exposure are the same, the short

- term assumptions and risk calculations are protective of both durations.

Mitigation/Personal Protective Equipment: 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 DMTA

- P product labels direct mixers, loaders, applicators and
other handlers to wear long

- sleeved shirts, long pants, shoes plus socks, and chemical

- resistant gloves made of any waterproof material.

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 exposures to workers were not aggregated because the toxicity endpoints for these exposure routes are not based on common tox icity effects in/of the liver. Dermal effects (body weight gain) were considered to be non

- specific.

Summary of Occupational Handler Non

- Cancer Exposure and Risk Estimates The results of the occupational handler exposure and risk assessment indicate that short

- and
intermediate

- term dermal and inhalation risk estimates are not of concern (i.e. all MOEs ≥ 100) at baseline mitigation (no PPE), except for the dermal exposure scenario of mixing and loading a liquid formulation of DMTA

- P for aerial application s which resulted in an MOE of 92

. With the use of additional PPE (i.e., gloves) the risk estimate MOE is mitigated to 540

. Inhalation MOEs ranged from 3,100 to 140,000 at baseline

. Note that only engineering control (enclosed cockpit)
data are available to assess risks to handlers operating aircrafts.

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 t he 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 in formation 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 enclo sed 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 control s,Page 18 of 36

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.Page 19 of 36

Table 6.1.1. Occupational Handler Non

- Cancer Exposure and Risk Estimates for DMTA

- P

.

Exposure Scenario Crop or Target Level of

Concern Dermal Unit

Exposure ( μ g/lb ai) 1 Inhalation Unit

Exposure ( μ g/lb ai) 1 Maximum

Application

Rate 2 Area

Treated or
Amount

Handled Daily 3 Dermal Inhalation

Mitigation

Level Mitigation

Level Dose (mg/kg/day) 4 MOE 5 Dose (mg/kg/day) 6 MOE 7

Mixer/Loader

Mixing/Loading Liquids for Aerial Applications

Cotton Subgroup

20C 100 220

(baseline)

37.6
(baseline + gloves) 0.219

(baseline: no respirator) 1.0 lb ai/A 1,200 3.25 (baseline)

0.555
(baseline + gloves) 92

(baseline)

540
(baseline +gloves) 0.0032

(baseline) 3,100

(baseline)

Mixing/Loading Liquids for Chemigation Applications 350 0.948
(baseline) 320

(baseline) 0.00094

(baseline) 11,000

(baseline)

Mixing/Loading Liquids
for Groundboom Applications 200 0.541
(baseline) 550

(baseline) 0.0005 4

(baseline) 19,000

(baseline)

Applicator

Applying Liquids with Aerial Equipment Cotton

Subgroup
20C 100 2.08

(Eng. Controls) 0.0049

(Eng. Controls)

1.0 lb ai/A 1,200 0.0308
(Eng. Controls) 9,700

(Eng. Controls) 0.0000724

(Eng. Controls) 140,000

(Eng. Controls)

Applying Liquids with Groundboom Equipment 78.6
(baseline) 0.34

(baseline) 200 0.194
(baseline) 1,500

(baseline) 0.0008 4

(baseline) 12,000

(baseline)

Flagger

Flagging Liquids for Aerial Applicaitons Cotton

Subgroup
20C 100 11

(baseline) 0.35

(baseline) 1.0 lb ai/A 350 0.047
(baseline) 6,300

(baseline) 0.0015

(baseline) 6,700

(baseline)

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

2 B ased on proposed label use (EPA Reg No. 7969

- 156 ).
3 Exposure Science Advisory Council Policy #9.1.

4 Dermal Dose = Dermal Unit Exposure ( μ g/lb ai) × Conversion Factor (0.001 mg/ μ g) × Application Rate (lb ai/acre or gal) × Area Treated or Amount Handled (A or gal/day) × DAF (%) ÷ BW (kg).
5 Dermal MOE = Dermal NOAEL (mg/kg/day) ÷ Dermal Dose (mg/kg/day).

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

7 Inhalation MOE = Inhalation NOAEL (mg/kg/day) ÷ Inhalation Dose (mg/kg/day).Page 20 of 36

6

. 2 Occupational Post

- application Exposure/ Risk Estimates

HED uses the term post

- application to describe exposures that occur when individuals are present in an environment that has been previously treated with a pesticide (also referred to as re

entry exposu re). 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 o n s uch 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 gre atly reduce the potential for post

- application exposure.

6

. 2 .1 Occupational Post

- application Inhalation Exposure/Risk Estimates

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

- application inhalation exposure assessment was not performed for DMTA

- P at this time primarily because of the low acute inhalation toxicity (Toxicity Category III), and the low proposed use rate (1.0 lb ai/A). However, there are multiple potential sources of post

- application inhalation exposure to individuals performin g 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 10

. The Agency is in the process of evaluating the SAP report as well as available post

- application inhalation exposure data generated by the ARTF and may, as appropriate, develop policies and procedures, to identify the need for and, subsequently, the way to incorporate occupational post

application inhalation exposur e into the Agency's risk assessments. If new policies or procedures are put into place, the Agency may revisit the need for a quantitative occupational
post

- application inhalation exposure assessment for DMTA

- P

.

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 t han post

- application exposure. Therefore, it is expected that these handler inhalation exposure estimates would be protective of most occupational post

- application inhalation exposure scenarios.

6

. 2 .2 Occupational Post

- application Dermal Exposure/Risk Es timates

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. For DMTA

- P

, since toxicological endpoints are the

10 Available: http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.htmlPage 21 of 36

same for both durations (short

- , and intermediat e) , short

- term risk estimate quantification is presented in this memo and considered protective of longer exposure durations.

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

recomm ended for use in predicting post

- application exposure that are used in this assessment, known as “transfer coefficients”, are presented in the ExpoSAC Policy 3 11 ” which, along with additional information about the ARTF data, can be found at the Agency website 12

. Table 6.2.2.1 provides a summary of the anticipated post

- application activities and associated transfer coefficients for the proposed crops/use sites.

Table 6

. 2 .2

. 1

. Anticipated Post

- Application Activities and Dermal Transfer Coefficients.

P roposed Crops Policy Crop Group Category Crop

Height Foliage

Density Transfer

Coefficients (cm 2 /hr ) Activities

Cotton Subgroup 20C Field / row crop, low /
medium Low Full/Min 210 Scouting

Full/Min 70 Weeding, Hand

Application Rate: Refer to the proposed use pattern table in Section 4.0.

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

Dislodgeable Foliar Residues : Chemical

- specific dislodgeable foliar residue data have not been
submitted for DMTA

- P

. Therefore, this assessment uses HED’s default assumption that 25% of the application is available for transfer on day 0 following the application and the residues dissipate at a rate of 10% each following day.

Dislodgeable Foliar Residue (DFR): In accordance with 40CFR1 58, DFR data are required for all occupational (e.g., crop, nursery, greenhouse use sites) or residential (e.g., ornamental and vegetable gardens, pick your own farms, retail tree farms) uses that could result in post

application exposure to foliage. In t he absence of chemical

- specific DFR data, EPA uses default
values. The 2012 Standard Operating Procedures for Residential Pesticide Exposure

Assessment includes an analysis of a number of DFR studies, which resulted in the selection of a
revised default v alues for the fraction of the application rate available for transfer after a foliar application (F AR ). These values are based on an analysis of 19 DFR studies. Since that time, the Agricultural Re

- entry Task Force has submitted information (MRID 492992 01) that corrects an application rate error made in the original submission of “ARF039

– Determination of Dermal and Inhalation Exposure to Reentry Workers During Chrysanthemum Pinching in a Greenhouse” (EPA MRID 45344501). As a result, the range of F AR v alues was revised from 2%

- 89% to 2%

- 47%. In the data, a large range of transferability is observed and this variability can potentially

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

12 Available: http://www.epa.gov/pesticides/s cience/post

- app

- exposure

- data.htmlPage 22 of 36

be attributable to many factors such as active ingredient; formulation; field conditions in the studies; weather co nditions (e.g., humidity); or many other difficult to quantify factors. Although witnessed across multiple chemicals, this range in F AR values is not expected when considering DFR data for a single chemical. At this time, the ARTF submission did not alte r the selection of 25% as the reasonable, high

- end default value. Because DFR data are not available
for DMTA

- P, EPA is using the default value of 25%. Although there may be a small degree of uncertainty in the use of the default DFR value for DMTA

- P (i. e., there is a small chance that the

F AR value may exceed the applicable default value ), it is likely that the health

- protective aspects of EPA’s occupational post

- application assessment methodology will more than compensate for this potential uncertainty. For example, when assessing residential and occupational post

application exposure to gardens and ornamentals, EPA assumes the following: exposures occur

to zero

- day (i.e., day of application ) residues every day of the assessed exposure duration (i.e

., EPA assumes that no dissipation or degradation occurs, it doesn’t rain, etc); individuals perform
the same post

- application activities performed in the transfer coefficient study day after day (e.g., weeding, harvesting, pruning, etc.); and individuals engage in these post

- application activities for a high

- end amount of time every day (represented by data reflecting time spent gardening based on survey data).

Given the conservatisms discussed above and the potential compounding nature of these conservatisms, EPA is able to rely upon the calculated exposure estimates with confidence that exposure is not being underestimated.

Since the highest estimated occupational post

- application exposure using default DFR values for

DMTA

- P is minimal in comparison to the level of concern (i.e., the calculated MOE is greater than 2 times higher than the level of concern, ( MOE = 5,100 compared to the LOC of 100); EPA
is waiving the 40CFR DFR data requirement. In this instance, it is unlikely that chemical

specific DFR data would be needed to further refine exposure assessments or would add appreciably to our overall understanding of the availability of dislodgeable foli ar pesticide
residues for DMTA

- P.

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

.

Oc cupational Post

- application Non

- Cancer Dermal Risk Estimates

Table 6

. 2 .2.2

. Occupational Post

- application Non

- Cancer Exposure and Risk Estimates for DMTA

- P

.

Crop/Site Activities Transfer Coefficient (cm 2 /hr) DFR 1 Dermal Dose (mg/kg/day) 2 MOE 3

LOC=100

Short

- and Intermediate

- term

Cotton Subgroup 20C Scouting 210 2.8 0.059 5,100

Weeding, Hand 70 0.020 15,000

1 DFR = Application Rate × F × (1

- D) t × 4.54E8 μg/lb × 2.47E

- 8 acre/cm 2 ; where F = 0.25 and D = 0.10 per day OR

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

3 MOE = POD ( mg/kg/day) / Daily Dermal Dose. Daily Dermal Dose = [DFR /TTR (μg/cm 2 ) × TC × 0.001 mg/μg × 8 hrs/day × dermal absorption factor (%) ]  BW (kg)

.Page 23 of 36

Restricted Entry Interval The REI specified on the proposed label is based on the acute toxicity of dimethenamid

- P

. Dimethenamid

- P is classified as Toxicity Category III via the dermal route , Toxicity Category III for eye irritation potential and Toxicity Category IV for skin irritation potential. It is a mild skin
sensitizer. Short

- and intermediate

- term post

- application risk estimates were not a concern on day 0 (12 hours following application) for all post

- application activities. Under 40 CFR 156.208 (c) (2) (iii), ai’s classified as Acute III or IV for acute dermal, eye irritation and primary skin

irri t ation are assigned a 12

- hour REI. Therefore, the [156 subpart K] Worker Protection Statement interim REI of 12 hours is adequate to prote ct agricultural workers from post

application exposures to DMTA

- P

.Page 24 of 36

Appendix A. Summary of Occupational and Residential Non

- cancer Algorithms

Residential Handler Exposure Calculations

Turf, Gardens and Trees, Indoor Environments

Dermal and Inhalation Handler Exposure Algorithm Daily dermal and inhalation exposure (mg/day) for residential pesticide handlers, for a given
formulation

- application method combination, is estimated by multiplying the formulation

appl ication method

- specific unit exposure by an estimate of the amount of active ingredient handled in a day, using the equation below:

E = UE * AR * A

where:

E = exposure (mg/day); UE = unit exposure (mg/lb ai); AR = application rate (e.g., lb ai/ft 2 , lb a i/gal); and A = area treated or amount handled (e.g., ft 2 /day, gal/day).

Residential Handler Dose Calculations

Dermal and/or inhalation absorbed doses normalized to body weight are calculated as:

D = E *AF / BW

where:

D = dose (mg/kg

- day);

E = exposure (mg/day); AF = absorption factor (dermal and/or inhalation); and BW = body weight (kg).

Residential Post

- application

Turf/Physical Activities on Turf

Post

- application Dermal Exposure Algorithm

– Physical Activities on Turf Exposure resulting fr om contacting previously treated turf while performing physical activities is calculated as shown below. Residential post

- application exposure assessment must include calculation of exposure on the day of application. Therefore, though an assessment can present exposures for any day “t” following the application, it must include “day 0” exposure.

E = TTRt * CF1 * TC * ETPage 25 of 36

where:

E = exposure (mg/day); TTRt = turf transferable residue on day t (μg/cm 2 ) (Chemical

- specific data, 0.352 for liquids, 0.0009 for solids) ; CF1 = weight unit conversion factor (0.001 mg/μg); TC = transfer coefficient (cm 2 /hr); and ET = exposure time (hr/day).

Dermal absorbed doses are calculated as:

where:

D = dose (mg/kg

- day);

E = exposure (mg/day);

AF = absorption factor (dermal); and

BW = body weight (kg).

Table A

- 1 : Turf (Physical Activities)

-- Inputs for Residential Post

- application Dermal Exposure

Algorithm Notation Exposure Factor (units) Po int Estimate(s)

AR Application rate (mass active ingredient per unit area) 1.5 lb ai/A

F Fraction of AR as TTR

following application (if
chemical

- specific data is unavailable) L/WP/WDG 0.01

Granules 0.002

F D Daily residue dissipation

(if chemical

- specific data is unavailable) (fraction) L/WP/WDG 0.1

Granules 0.1

TC Transfer

Coefficient (cm 2 /hr) L/WP/WDG Adults 180,000
Children 1 < 2 years old 49,000

Granules Adults 200,000

Children 1 < 2 years old 54,000

ET Exposure Time

(hours per day) Adults 1.5 Children 1 < 2 years old 1.5

BW Body Weight (kg) Adults 80

Children 1 < 2 years old 11 L/WP/WDG = Liquids/Wettable Powders/Water

- dispersible Granules

Post

- application Hand

- to

- Mouth Exposure Algorithm

– Physical Activities on Turf Exposure from hand

- to

- mouth activity is calculated as follows (based on the algorithm utilized in
the SHEDS

- Multimedia model ):

E = [HR * ( F

M * SA H ) * (ET * N_Replen) * (1

- (1

- SE ) (Freq_HtM/N

- Replen) )]Page 26 of 36

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 = saliv a extraction factor (i.e., mouthing removal efficiency); and Freq_HtM = number of hand

- to

- mouth contacts events per hour (events/hour).

and

where:

HR = hand residue loading (mg/cm 2 );
Fai hands = fraction ai on hands compared to total surface residue from dermal transfer coefficient study (unitless); DE = dermal exposure (mg); and

SA H = 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 A

- 2 : Turf (Physical Activities)

– Inputs for Residential Post

- application Hand

- to

- Mouth Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

Fai hands Fraction of ai on hands

from dermal transfer coefficient study (unitless) Liquid formulations 0.06

Granular formulations 0.027

DE Dermal exposure (mg) Calculated

SA H Typical surface area of one hand (cm 2 ), children 1 <

2 years old 150Page 27 of 36

Table A

- 2 : Turf (Physical Activities)

– Inputs for Residential Post

- application Hand

- to

- Mouth Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

AR Application rate

(mass active ingredient per unit area) 1.5 lb ai/A

HR Residue available on the hands (mg/cm 2 ) Calculated via (DE * Fai hands )/SA H

F M Fraction hand surface area mouthed (fraction/event) 0.127

N_Replen Replenishment intervals per hour (intervals/hr) 4

ET Exposure time (hrs/day) 1.5

SE Saliva extraction factor (unitless) 0.48

Freq_HtM Hand

- to

- mouth events per hour (events/hr) 13.9

BW Body Weight

(kg) Children 1 < 2 years
old 11

Post

- application Object

- to

- Mouth Exposure Algorithm

– Physical Activities on Turf Exposure from object

- to

- mouth activity is calculated as follows (based on the algorithm utilized
in SHEDS

- Multimedia):

E = [OR* CF1 * SAM O * (ET * N_Replen) * (1

- (1

- SE O ) (Freq_OtM/N_Replen) )]

where:

E = exposure (mg/day); OR = chemical residue loading on the object on day “t” (ug/cm 2 ); CF1 = weight unit conversion factor (0.001 mg/μg);

SAM O = area of the object surface that is mouthed (cm 2 /event); ET = exposure time (hr/day); N_Replen = number of replen ishment intervals per hour (intervals/hour);

SE O = saliva extraction factor (i.e., mouthing removal efficiency); and Freq_OtM = number of object

- to

- mouth contact events per hour (events/hour).

and

OR = AR * F O * CF2 * CF3

where:

OR = chemical residue loading on the object (μg/cm 2 ); AR = application rate (lbs ai/ft 2 or lb ai/acre);

F O = fraction of residue available on the object (unitless); CF2 = weight unit conversion factor (4.54 x 10 8 μg/lb); and CF3 = area unit conversion factor (1.08 x 10

- 3 ft 2 /cm 2 or 2.47 x 10

- 8 acre/cm 2 ).Page 28 of 36

Dose, normalized to body weight, is calculated as:

where:

D = dose (mg/kg

- day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A

- 2 : Turf (Physical Activities)

– Inputs for Residential Post

- application Object

- to

- Mouth Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

AR Application rate (to turf)

(mass active ingredient per unit area) 1.5 lb ai/A

F O Fraction of AR as OR following application 1 0.01

SAM O Surface area of object mouthed (cm 2 /event) 10

N_Replen Replenishment intervals per hour (intervals/hour) 4

SE O Saliva extraction factor (fraction) 0.48

ET Exposure time (hours per day) 1.5

Freq_OtM Object

- to

- mouth events per hour (events/hr) 8.8

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

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

Post

- application Incidental Soil Ingestion Exposure Algorithm

– Physical Activities on Turf Exposure from incidental soil ingestion is calculated as follows:

E = SRt * SIgR * CF1

where: E = exposure (mg/day); SRt = soil residue on day "t" (μg/g); SIgR = ingestion rate of soil (mg/day); and CF1 = weight unit conversion factor (1 x 10

- 6 g/μg).

and

SRt = AR * FS * (1

- F D ) t * CF2 * CF3 * CF4

where:

SR t = soil residue on day "t" (μg/g); AR = application rate (lbs ai/ft 2 or lb ai/acre);Page 29 of 36

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

F D = fraction of residue that dissipates daily (unitless); T = post

- application day on which exposure is being assessed; CF2 = weight unit conversion factor (4.54 x 10 8 μg/lb);

CF3 = area un it conversion factor (1.08 x 10

- 3 ft 2 /cm 2 or 2.47 x 10

- 8 acre/cm 2 ); and CF4 = soil volume to weight unit conversion factor (0.67 cm 3 /g soil).

Dose, normalized to body weight, are calculated as:

where : D = dose (mg/kg

- day);

E = exposure (mg/day); and

BW = body weight (kg).

Table A

- 3 : Turf (Physical Activities)

– Inputs for Residential Post

- application Incidental Soil Ingestion Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

AR Application rate

(mass active ingredient per unit area) 1.5 lb ai/A

FS Fraction of AR available in uppermost 1 cm of soil (unitless) 1

F D Daily residue dissipation (fraction) 0.1

SIgR Soil ingestion rate (mg/day) 50

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

Post

- application Episodic Granular Ingestion Exposure Algorithm

– Physical Activities on Turf Exposure from incidental ingestion of pesticide pellets or granules is calculated as follows:

E = GIgR* FD * CF1

where: E = exposur e (mg/day); GIgR = ingestion rate of dry pesticide formulation (g/day); FD = fraction of ai in dry formulation (unitless); and CF1 = weight unit conversion factor (1,000 mg/g).

Dose, normalized to body weight, are calculated as:

where : D = dose (mg/kg

- day);Page 30 of 36

E = exposure (mg/day); and

BW = body weight (kg).

Table A

- 4 : Turf (Physical Activities)

– Inputs for Residential Post

- application Episodic Granular Ingestion Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

F D Fraction of active ingredient in dry formulation 0.8%

AR Application rate (lbs/A or lbs/1,000 ft 2 ) 1.5 lb ai/A

GIgR Granule ingestion rate per day (g/day) 1 0.3

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

1 See discussion below on how this value may be adjusted if product specific information is available.

Turf/Mowing

Post

- application Dermal Exposure Algorithm

– Mowing Exposure resulting from contacting previously treated turf while mowing is calculated as follows:

E = TTRt * CF1 * TC * ET

where :

E = exposure (mg/day);

TTR t = turf transferable residue on day "t" (μg/cm 2 ) (Chemical

- specific data, 0.352 for liquids, 0.0009 for solids) ; CF1 = weight unit conversion factor (0.001 mg/μg);
TC = transfer coefficient (cm 2 /hr); and ET = exposure time (hr/day).

Absorbed dose, normalized to body weight, are calculated as:

where : D = dose (mg/kg

- day);

E = exposure (mg/day);

AF = absorption factor (dermal); and

BW = body weight (kg ).

Table A

- 5 : Turf (Mowing)

– Inputs for Residential Post

- application Dermal Exposure

Algorithm Notation Exposure Factor (units) Point Estimate(s)

AR Application rate 1.5 lb ai/APage 31 of 36

Table A

- 5 : Turf (Mowing)

– Inputs for Residential Post

- application Dermal Exposure mass active ingredient per unit area

F AR Fraction of AR as TTR following application L/WP/WDG 0.01

Granules 0.002

F D Daily residue dissipation L/WP/WDG 0.1

Granules 0.1

TC Transfer Coefficient (cm 2 /hr) Adult 5,500

Children 11 < 16 years
old 4,500

ET Exposure time (hours per day) 1

BW Body Weight (kg) Adults 80

Children 11 < 16 years
old 57

L/WP/WDG = liquid/wettable powder/water dispersible granule

Turf/Golfing

Post

- application Dermal Exposure Algorithm

– Golfing Exposure resulting from contacting previously treated turf while golfing is calculated as follows:

E = TTRt * CF1 * TC * ET

where :

E = exposure (mg/day);

TTR t = turf transferable residue on day "t" (μg/cm 2 ) (Chemical

- specific data, 0.352 for liquids, 0.0009 for solids) ; CF1 = weight unit conversion factor (0.001 mg/μg);
TC = transfer c oefficient (cm 2 /hr); and ET = exposure time (hr/day).

Absorbed dose, normalized to body weight, is calculated as:Page 32 of 36

where : D = dose (mg/kg

- day);

E = exposure (mg/day);

AF = absorption factor (dermal); and

BW = body weight (kg).

Table A

- 6 : Turf (Golfing)

– Inputs for Residential Post

- application Dermal Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

AR Application rate (mass active ingredient per unit area) 1.5 lb ai/A

F Fraction of AR as TTR

following application L/WP/WDG 0.01

Granules 0.002

F D Daily residue dissipation L/WP/WDG 0.1

Granules 0.1

TC Transfer Coefficient

(cm 2 /hr) Adult 5,300

Children 11 < 16 years old 4,400 Children 6 < 11 years old 2,900

ET Exposure time

(hours per day) Pesticides used on greens, tees, and fairways 4

Pesticides used only on greens

and tees 1

BW Body Weight (kg) Adults 80

Children 11 < 16 years old 57 Children 6 < 11 years old 32 NA = not applicable L/WP/WDG = liquid/wettable powder/water dispersible granule

Gardens and Trees

Post

- application Dermal Exposure Algorithm Exposure resulting from contacting previously treated gardens and trees while performing physical activities is calculated as shown below. Residential post

- application exposure assessment must include calculation of exposure on the day of application. Therefore, though an assessment can present exposures for any day “t” following the application, it must include “day 0” exposure.

E = DFR t * CF1 * TC * ET

where :

E = exposure (mg/day);

DFR t = dislodgeable foliar residue on day "t" (μg/cm 2 ); CF1 = weight unit conversion factor (0.001 mg/μg); TC = transfer coefficient (cm 2 /hr); andPage 33 of 36

ET = exposure time (hrs/day).

In the absence of chemical

- specific data, DFR t can be calculated as follows:

DFR t = AR * F

AR * (1

- F

D ) t * CF2 * CF3

where :

DFR t = dislodgeable foliar residue on day "t" (μg/cm 2 ); AR = application rate (lbs ai/ft 2 or lb ai/acre);

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

F D = fraction of residue that dissipates daily (unitless);
t = post

- application day on which exposure is being assessed; CF2 = weight unit conversion factor (4.54 x 10 8 μg/lb); and CF3 = area unit conversion factor (1.08 x 10

- 3 ft 2 /cm 2 or 2.47 x 10

- 8 acre/cm 2 ).

Absorbed dermal dose, normalized to body weight, is calculated as:

where : D = dose (mg/kg

- day);

E = exposure (mg/day);

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

BW = body weight (kg).

Table A

- 7 : Gardens, Trees, and “Pick

- your
- own” Farms

– Inputs for Residential Post

- application Dermal Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

AR Application rate (mass ai per unit area) 1.5 lb ai/A

F AR DFR following application, if chemical

- specific is unavailable (fraction) 0.25

F D Daily residue dissipation, if chemical

- specific is unavailable (fraction) 0.10

TC Transfer

Coefficient (cm 2 /hr) Gardens a Adults 8400 Children 6 < 11 years old 4600 Trees, Retail Plants (if applicable) a Adults 1700

Children 6 < 11 years old 930

Indoor Plants Adults 220 Children 6 < 11 years old 120

ET Exposure

Time (hours per day) Home activities b Gardens Adults 2.2 Children 6 < 11 years
old 1.1

Trees, Retail Plants (if applicable) Adults 1.0

Children 6 < 11 years
old 0.50Page 34 of 36

Table A

- 7 : Gardens, Trees, and “Pick

- your
- own” Farms

– Inputs for Residential Post

- application Dermal Exposure Algorithm
Notation Exposure Factor (units) Point Estimate(s)

Indoor Plants Adults 1.0

Children 6 < 11 years
old 0.50

“Pick

- your

- own” Farms (if applicable) Adults 5.0

Children 6 < 11 years old 1.9

BW Body weight (kg) Adults 80

Children 6 < 11 years old 32

a Transfer coefficient point estimates from a composite distribution assuming equal proportion of time spent conducting various activities. See “Transfer Coefficient” section below. Children 6 < 11 years old TC derived using surface area adjustment (see S ection 2.3 ).

b Activity time point estimates from a composite distribution assuming equal proportion of each respective activity. Time for children 6 < 11 years old derived using hrs/day ratio adjustment. See “Exposure Time”

section below and Section Error! Reference source not found. of Appendix D,

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 = e xposure (mg ai/day),

UE = u nit e xposure (μ g ai/ lb ai),

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

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

.

The daily doses are calculated using the following formula:

ADD= E * AF

BW

where:

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

E = e xposure (mg ai/day),

AF = absorption fa ctor (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 occupationalPage 35 of 36

handlers a re compared to the appropriate POD ( i.e.

, NOAEL) to assess the risk to occupational handlers for each exposure route. All MOE values a re calculated using the following formula:

MOE= POD

ADD

where:

MOE = m argin of e xposure: value used by HED to represent risk estimates (unitless),

POD = p oint of d eparture (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:

DFR t =AR * F* (1

- D) t * ( 4.54E8 ug
lb ) * ( 2.47E

- 8 A

cm 2 )

where:

DFR t = dislodgeable foliage residue on day "t" (μg/cm 2 ),

AR = a pplication r ate (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 * 0.001 mg

ug

where:

E = e xposure (mg ai/day),

TC = t ransfer coefficient (cm 2 /hr),

DFR t = d islodgeable f oliar r esidue on day “t” (μg/cm 2 ), and

ET = e xposure t ime (hours/day).

The daily doses are calculated using the following formula:

ADD= E * AF

BW

where:Page 36 of 36

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

E = e xposure (mg ai/day),

AF = absorption fa ctor (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 a re calculated using the following formula:

MOE= POD

ADD

where:

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

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

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