Document ID: EPA-HQ-OPP-2009-0798-0010
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2010-11-10T05:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF           

PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM  

Date:		October 12, 2009 

Subject:	Flurprimidol: Occupational and Residential Exposure/Risk
Assessment of Flurprimidol for Section 3 Registration of New Uses in
Residential and Non-Occupational Settings    

		PC Code: 125701                         DP Barcode: D357307

                        MRID No.:                                  
Registration No.:   67690-16     

		Petition No.:  NA                         Regulatory Action:
Registration

                        Assessment Type: ORE              
Reregistration Case No.:  None

                        TXR No.:   None                          CAS
No.:  56425-91-3      

                        Decision No.:  398756                  40 CFR: 
NA  

	

TO:		Rosemary Kearns/Tony Kish (RM22)

		Registration Division (7505P)

		Office of Pesticide Programs

FROM:	Shih-Chi Wang, Biologist

		Risk Assessment Branch 2

		Health Effects Division (7509P)

THRU:	Richard Loranger, Branch Senior Scientist

		Risk Assessment Branch 2

		Health Effects Division (7509P)

CONCLUSIONS

The potential occupational and residential exposures/risks resulting
from the proposed uses do not exceed the Health Effects Division’s
(HED’s) level of concern.  

BACKGROUND

The enclosed document is an assessment of potential occupational and
residential exposures/ risks to support the proposed Section 3
registration for new uses of flurprimidol in residential and
non-occupational settings.  

1.0      Executive Summary tc \l1 "1.0  Executive Summary 

A Section 3 registration is being requested by SePRO Corporation for
five end-use products containing flurprimidol as active ingredient. 
SePRO seeks to expand the already approved use sites of five registered
products (Cutless 0.33G Landscape Growth Regulator, EPA Reg. No.
67690-13; Cutless 50W Turf Growth Regulator, EPA Reg. No. 67690-15; Turf
Fertilizer-Contains Cutless 0.375%, EPA Reg.No. 67690-19; Turf
Fertilizer-Contains Cutless 0.17%, EPA Reg. No. 67690-44; and SP5075
Turf Growth Regulator, EPA Reg. No. 67690-46) to include use on turf and
ornamentals in residential & non-occupational settings and, in the case
of Cutless 0.33G, to homeowner applications.

Toxicological points of departure (PODs) were selected from a
developmental toxicity (gavage) study in the rat and from a 90-day oral
toxicity (diet) study in the dog.  An oral NOAEL of 10 mg/kg/day (based
on decreased maternal body weight & food consumption and in fetuses,
increased incidences of hydronephrosis, hydroureter, microphthalmia &
anomalies in the vertebrae and ribs) was selected for assessing
short-term incidental oral, dermal and inhalation risks.  An oral NOAEL
of 1.5 mg/kg/day (based on decreased adrenal weights & histopathology)
was selected for assessing intermediate-term incidental oral, dermal and
inhalation risks.  The dermal and inhalation absorption rates were 6%
and 100% respectively.  Daily dermal and inhalation doses were combined
and then compared to the NOAEL to determine the level of risk.  The
level of concern for the margin of exposure (MOE) is 100.  Flurprimidol
is classified as “not likely to be carcinogenic to humans”,
therefore, the cancer risk is not of concern.    

 

The number of exposure days per year was not provided.  Based on the
frequency/interval of applications, EPA assumes that both occupational
handlers and post-application workers would be exposed for less than 6
months per year (short- and intermediate-term exposures).  Residential
exposures are expected to be short-term only (1-30 days).  Long-term
exposures are not expected.

HED used surrogate data from the PHED Version 1.1 (PHED Surrogate
Exposure Guide, 8/98), unit exposures from Outdoor Residential Exposure
Task Force (ORETF), and unit exposures  from two chemical-specific
exposure studies (MRID 40184414 & 40184415) to assess exposures for the
proposed uses.  Defaults established by the HED Science Advisory Council
for Exposure (Expo SAC), and Residential SOP were used for acres treated
per day and body weight.  Although the chemical-specific studies
generated foliar residue data, the methodology used was not appropriate
for assessing turf transferable residues.    

For Occupational Exposures: Except the intermediate-term MOE for
mixing/loading liquid for ground-boom application, all other MOEs for
occupational handlers performing proposed uses are greater than 100 (110
~ 3,300) at the baseline level (single layer, no gloves).  The
intermediate-term MOE for mixing/loading liquid for ground-boom
application is 29 at single layer/no gloves level, but the MOE increases
to 2,000 at single layer plus gloves level.  Most of the
post-application MOEs are greater than 100.  Although the
intermediate-term MOE for course maintenance is less than 100 (MOE=66),
HED is not concerned since the assessment assumes zero day residues
every day and therefore greatly overestimates exposure, especially
considering the irrigation that is required within a day of application.

For Residential Exposures:  The MOEs for residential handlers performing
Turf Fertilizers applications using Belly Grinder, Push-Type Spreader,
and hand application are 1,200, 20,000, and 3,700 respectively.  These
MOEs are greater than 100 and do not exceed HED’s level of concern. 
All post-application MOEs for adult and child residents are greater than
100 (130 ~ 130,000) and therefore do not exceed HED’s level of
concern.  

 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 studies, which comprise the Pesticide Handlers Exposure
Database (PHED) and information from the Agricultural Re-Entry Task
Force (ARTF) & the Outdoor Residential Exposure Task Force (ORETF), have
been determined to require a review of their ethical conduct, and have
received that review. The studies in PHED and from the ARTF and ORETF
were considered appropriate (or ethically conducted) for use in risk
assessments.



  SEQ CHAPTER \h \r 1 2.0 	Ingredient Profile

Flurprimidol is a turf grass and woody-plant growth regulator that
belongs to the pyrimidine class of chemicals.  The original registration
was for use on ornamental plants grown in containers in commercial
greenhouses and shadehouses.  The proposed uses would expand the
applications to include residential settings with treatment of both turf
and ornamentals.  Flurprimidol works through inhibition of gibberellin
biosynthesis in the early stages of the pathway.  This early blockage
prevents the synthesis of numerous gibberellins needed for normal plant
growth and development. 

  SEQ CHAPTER \h \r 1 Structure and Nomenclature

Table 1.	Test Compound Nomenclature

Chemical Structure	

Empirical Formula	C15H15F3N202

Common name	Flurprimidol

Company experimental name	N/A

IUPAC name	alpha-(1-methylethyl)-alpha-[4-(trifluoromethyoxy)
phenyl]-5-pyrimidinemethanol 

CAS name	alpha-(1-methylethyl)-alpha-[4-(trifluoromethyoxy)
phenyl]-5-pyrimidinemethanol 

CAS Registry Number	056425-91-3

End-use product/EP	Topflor

Chemical Class	pyrimidine plant growth regulator

Known Impurities of Concern	N/A

3.0  Hazard Information tc \l1 "2.0  Hazard Information 

Hazard and Dose-Response Characterization

This hazard and dose-response characterization updates the previous
characterization, prepared in support of a Section 3 registration for
use on ornamental plants grown in greenhouses and shadehouses (D318716,
September 29, 2005).  Changes include the selection of incidental oral
endpoints for hand-to-mouth exposure of children from treated turf and
additional toxicology data requirements, based on the recently revised
40 CFR Part 158.  

3.1.1.	Database Summary

  TC \l3 "3.1.1	Database Summary 

Studies available and considered (animal, human, general literature)

Acceptable studies include acute lethality,   TC \l4 "3.1.1.1	Studies
available and considered (animal, human, general literature) eye/skin
irritation, skin sensitization, subchronic and chronic oral toxicity in
the rat, mouse and dog, rat and rabbit developmental toxicity studies,
rat reproductive toxicity, rat and mouse carcinogenicity, rabbit dermal
toxicity, genotoxicity and rat general metabolism. No new studies have
been submitted since the 2005 risk assessment.

3.1.1.2	Mode of action, metabolism, toxicokinetics   TC \l4 "3.1.1.2
Mode of action, metabolism, toxicokinetic data 

β-hydroxy-α-methyl-β-[4-(trifluoromethoxy)
phenyl]-5-pyrimidinepropanoic acid, constituted 10-20% of the dose. 
Metabolism does not show qualitative differences dependent on sex, dose
level or repeated dosing.  Tissue bioaccumulation was not observed.

Sufficiency of studies/data

In accordance with the revised 40 CFR Part 158, additional studies are
required to satisfy toxicology data requirements.  Rat acute and
subchronic neurotoxicity studies and an immunotoxicity study are
required.  A rat 28-day inhalation toxicity study is also required,
based on the potential for significant inhalation exposure.  However,
based on lack of evidence of neurotoxicity or immunotoxicity and use of
oral studies for route-to-route extrapolation for inhalation exposure
assessment, the database is considered adequate for purposes of this
risk assessment and an additional database uncertainty (UFDB) is not
applied.

3.1.2	Toxicological Effects  TC \l3 "3.1.2	Toxicological Effects 

The toxicity profile of flurprimidol is provided in Table 2.  

Flurprimidol has low acute toxicity (Category III and IV) via all routes
of exposure.  It is slightly irritating to the skin (IV) and moderately
irritating to the eye (III) but is not a dermal sensitizer.

The critical effects observed after flurprimidol exposure involve the
adrenal gland and the liver.  In a 90-day oral toxicity study and a
1-year chronic toxicity study in the dog, small adrenal glands,
decreased adrenal weights, increased incidences of adrenal cortical
vacuolation, microscopic lesions and reduced response to
adrenocorticotropic hormone (ACTH) were observed in males and females. 
Liver toxicity observed in a combined chronic toxicity/carcinogenicity
study included increased incidences of focal basophilic atypia, fatty
change and hepatocellular eosinophilic change.  These findings were not
observed in subchronic studies in rats and mice, nor in a mouse
carcinogenicity study, up to the highest doses tested.

Developmental effects were observed at maternally toxic doses.  In the
rat, increased incidences of hydronephrosis, hydroureter, microphthalmia
and skeletal anomalies in the vertebrae and ribs were observed in
fetuses at a dose that also caused maternal toxicity.  No maternal or
developmental effects were observed in the rabbit developmental study
but abortion, weight loss and decreased food consumption occurred at a
higher dose in the range-finding study.  

Flurprimidol was associated with reproductive toxicity and possibly
endocrine disruption. In a rat two-generation reproductive toxicity
study, an increased incidence of persistent vaginal estrous along with
decreased mating and fertility were observed in both generations at the
reproductive LOAEL.  The significance of the vaginal estrous as related
to decreased mating and fertility is unclear.  Other related pyrimidine
compounds have been shown to inhibit testosterone aromatase activity. 
Consequently, when screening and/or testing protocols have been
developed, it is recommended that flurprimidol be examined to
characterize effects related to endocrine disruption.  The risk
assessment for flurprimidol is based on much lower doses and is
therefore protective of the effects seen at 74 mg/kg/day.

Flurprimidol did not show evidence of neurotoxicity.  Although clinical
signs consistent with possible neurotoxicity (e.g., pallor, tremors,
hindlimb weakness, myoclonic jerking, lacrimation, salivation) were
reported in mid and high dose P females during gestation and lactation
in the rat reproductive toxicity study, they were observed in only a few
females and were associated with mortality; additionally, F1 parental
females and males of both generations were not affected.  There were no
indications of neurotoxicity in other studies (acute and subchronic
neurotoxicity studies have not been submitted), including the rat or
rabbit developmental studies.  

Flurprimidol is classified as “Not likely to be carcinogenic to
humans.”  There was no evidence of treatment-related increased tumor
incidence in the rat or mouse, although the mouse study did not achieve
a maximum tolerated dose.  Flurprimidol showed no evidence of
genotoxicity.

Table 2.  Acute Toxicity Profile of Flurprimidol (tech. a.i.)

Guideline No.	Study Type	MRID #	Results	Toxicity Category

870.1100	Acute Oral, Rat	00117933	LD50 = 914 (M) or 709 (F) mg/kg	III

870.1200 	Acute Dermal, Rabbit	00010214*	LD50  >500 mg/kg, both sexes
III

870.1300	Acute Inhalation, Rat	40401009	

LC50 = 5.231 mg/L, both sexes	IV

870.2400 	Primary Eye Irritation, Rabbit	00248752	Moderate ocular
irritant	III

870.2500 	Primary Skin Irritation, Rabbit	40401008	Slight dermal
irritant	IV

870.2600 	Dermal Sensitization, Guinea Pig	00162766	Not a dermal
sensitizer	N/A

 N/A:  Not applicable to this guideline study

The MRID number for the acute dermal study is not available; number
indicated is toxicology record number.

Dose-response

Dietary endpoints were not selected because there are no food uses for
flurprimidol.

For short-term incidental oral exposure (young children), the maternal
toxicity NOAEL of 10 mg/kg/day (rat developmental toxicity study) was
selected as appropriate for the route and duration of exposure.  The
endpoints of concern were decreased body weight and food consumption at
the LOAEL of 45 mg/kg/day.  The NOAEL is protective of offspring, since
developmental effects were only observed at maternally toxic doses.  In
the rat two-generation reproductive toxicity study, a comparable
offspring NOAEL of 7.3 mg/kg/day was observed based on decreased pup
survival and body weight at the LOAEL of 74 mg/kg/day.  The slightly
lower offspring NOAEL is attributed to dose spacing rather than endpoint
sensitivity.  

For intermediate-term incidental oral exposure (young children), the
NOAEL of 1.5 mg/kg/day (dog 90-day oral study) was selected as the most
sensitive available endpoint appropriate for the route and duration of
exposure.  The effects of concern were adrenal histopathology and
decreased adrenal weight and size, observed at the LOAEL of 30
mg/kg/day.  The endpoint is protective of offspring (see above).

.  

For both dermal and inhalation short-term occupational and
non-occupational exposure, the maternal toxicity NOAEL of 10 mg/kg/day
from the rat developmental toxicity study was selected as the most
sensitive endpoint appropriate for the route and duration of exposure.

For both dermal and inhalation intermediate-term occupational and
non-occupational exposure, the NOAEL of 1.5 mg/kg/day from the dog oral
toxicity study was selected as the most sensitive endpoint appropriate
for the route and duration of exposure.

 

Long-term exposure and cancer risk assessments were not performed. 
There are no long-term exposures anticipated from use of flurprimidol
and no cancer risk was identified.

Because oral studies were selected, relative absorption was estimated
for dermal and inhalation exposure.  Acceptable dermal absorption data
were not available.  Dermal absorption was therefore estimated at 6% by
comparing the rabbit 21-day dermal toxicity NOAEL (no toxicity was
observed up to the limit dose) to the rabbit oral maternal toxicity
LOAEL (developmental study).  Inhalation absorption was assumed to be
100% relative to oral absorption (default).

3.1.4	FQPA  TC \l3 "3.1.4	FQPA 

An assessment of FQPA hazard considerations is not required because
there are no food uses of flurprimidol.    

Absorption, Distribution, Metabolism, Excretion (ADME)

30 metabolites.  The primary metabolite was tentatively identified as
β-hydroxy-α-methyl-β-[4-(trifluoromethoxy)
phenyl]-5-pyrimidinepropanoic acid and was present at 10-20% of the
dose, mainly in the urine.  Other metabolites individually accounted for
less than 6% of the dose; parent was present in feces at less than 2.5%
of dose.  Eleven metabolites were tentatively identified.  Major
metabolic pathways included oxidation of the isopropyl group and the
pyrimidine ring.  

Dermal absorption is low, based on lack of effects in a rabbit 21-day
dermal toxicity study (local dermal irritation was observed at the site
of application).  An estimated absorption of 6% was calculated, based on
comparison of available dermal (21-day) and oral (developmental
toxicity) studies in the rabbit (see Section 3.5.4).  There are no
studies evaluating the toxicity or metabolism of flurprimidol following
inhalation exposure.  

FQPA Considerations

An FQPA assessment is not required because there are no food uses of
flurprimidol at this time.

Hazard Identification and Toxicity Endpoint Selection

Acute Reference Dose (aRfD) and Chronic Reference Dose (cRfD) – All
Populations  TC \l3 "3.5.1    Acute Reference Dose (aRfD) - Females age
13-49 

Dietary endpoints were not selected because there are currently no food
uses for flurprimidol.

Incidental Oral Exposure (Short-Term) 

Study Selected:  Developmental Toxicity (rat)	

MRID No.:  000147301

Dose and Endpoint for Risk Assessment:  Maternal toxicity NOAEL = 10
mg/kg/day based on decreased body weight and food consumption at LOAEL =
45 mg/kg/day.

Comments about Study/Endpoint/Uncertainty Factors:   The maternal
toxicity NOAEL of 10 mg/kg/day represents the most sensitive endpoint
available for this exposure scenario.  The route of exposure (oral) and
duration of this study are appropriate for incidental exposure of short
duration (1-30 days).  The NOAEL is protective of developmental effects.
 Developmental toxicity was not observed at lower doses.  An offspring
NOAEL of 7.3 mg/kg/day was observed in the rat reproductive toxicity
study (MRID 00162770), with a LOAEL of 74 mg/kg/day (decreased survival
and pup body weights).  The lower NOAEL in the reproductive study is
attributed to dose selection rather than greater sensitivity of the
endpoint.  A combined uncertainty factor (UF) of 100 (10x interspecies
extrapolation and 10x intraspecies variability) was used.  An additional
database uncertainty factor (UFDB) due to lack of neurotoxicity and
immunotoxicity studies was not applied because there is no evidence of
neurotoxicity or immunotoxicity.

Incidental Oral Exposure (Intermediate-Term)

Study Selected:    90-Day Oral Toxicity (dog)

MRID No.:  00162768

Dose and Endpoint for Risk Assessment:  NOAEL = 1.5 mg/kg/day based on
adrenal effects (small size, decreased weight and histopathology) at
LOAEL = 30 mg/kg/day.

Comments about Study/Endpoint/Uncertainty Factors:  The NOAEL of 1.5
mg/kg/day represents the most sensitive endpoint available for this
exposure scenario.  The route of exposure (oral) and duration of this
study are appropriate for incidental exposure of intermediate duration
(1-6 months).  The NOAEL is protective of developmental effects. 
Developmental toxicity was not observed at lower doses.  An offspring
NOAEL of 7.3 mg/kg/day with LOAEL of 74 mg/kg/day (decreased survival
and pup body weights) was observed in the rat reproductive toxicity
study (MRID 00162770).  The lower NOAEL in the reproductive study is a
result of dose selection, rather than greater sensitivity of the
endpoint.  A combined uncertainty factor (UF) of 100 (10x interspecies
extrapolation and 10x intraspecies variability) was used.  An additional
database uncertainty factor (UFDB) due to lack of neurotoxicity and
immunotoxicity studies was not applied because there is no evidence of
neurotoxicity or immunotoxicity.

  TC \l3 "3.5.4	Incidental Oral Exposure (Short- and Intermediate-Term) 

3.5.4	Dermal Absorption

A dermal penetration study in monkeys was unacceptable due to general
problems and several study deficiencies.  A 21-day dermal toxicity study
in rabbits was also submitted.  There was no systemic toxicity observed
up to the limit dose of 1000 mg/kg/day.  Very slight dermal irritation
was observed at 500 mg/kg/day, but was not considered to be of concern. 
A dermal absorption factor of 6.0% was estimated by comparison of the
oral maternal toxicity LOAEL and dermal systemic toxicity NOAEL from the
rabbit developmental toxicity and dermal toxicity studies, respectively.
 Normally, the dermal absorption factor would be calculated by comparing
the oral and dermal LOAELs for a comparable endpoint.  However, the
dermal NOAEL was used since there were no systemic effects observed in
the dermal study.  

   

   = 0.06 x 100% = 6%

Dermal Exposure (Short-Term)

Study Selected:  Developmental toxicity (rat)

MRID No.:  00147301

Dose and Endpoint for Risk Assessment:  See Section 3.5.2

Comments about Study/Endpoint/Uncertainty Factors:   The maternal
toxicity NOAEL of 10 mg/kg/day from the rat developmental toxicity study
represents the most sensitive endpoint available for this exposure
scenario and the duration of this study is appropriate for a short-term
exposure assessment (1-30 days).  Since an oral dose was selected, a
dermal absorption factor of 6% was applied for route-to-route
extrapolation (see Section 3.5.4).  A combined uncertainty factor (UF)
of 100 (10x interspecies extrapolation and 10x intraspecies variability)
was used.  An additional database uncertainty factor (UFDB) due to lack
of neurotoxicity and immunotoxicity studies was not applied because
there is no evidence of neurotoxicity or immunotoxicity.

Dermal Exposure (Intermediate-Term)

Study Selected:    90-Day Oral Toxicity (dog)

MRID No.:  00162768

Dose and Endpoint for Risk Assessment:  See Section 3.5.3

Comments about Study/Endpoint/Uncertainty Factors:   The NOAEL of 1.5
mg/kg/day from the 90-day dog oral study represents the most sensitive
endpoint available for this exposure scenario.  The duration of this
study is appropriate for incidental exposure of intermediate-term
duration (1-6 months).  Since an oral dose was selected, a dermal
absorption factor of 6% was applied for route-to-route extrapolation
(see Section 3.5.4).  A combined uncertainty factor (UF) of 100 (10x
interspecies extrapolation and 10x intraspecies variability) was used. 
An additional database uncertainty factor (UFDB) due to lack of
neurotoxicity and immunotoxicity studies was not applied because there
is no evidence of neurotoxicity or immunotoxicity.

Dermal Exposure (Long-Term) 

Long-term dermal exposure is not anticipated; therefore this risk
assessment is not required.

Inhalation Exposure (Short-Term) 

Study Selected:  Developmental Toxicity (rat)	

MRID No.:  00147301 

Dose and Endpoint for Risk Assessment:  See Section 3.5.2

Comments about Study/Endpoint/Uncertainty Factors:   See Section 3.5.5. 
A default inhalation absorption rate of 100% is assumed relative to oral
absorption, as an inhalation study and/or data on inhalation absorption
are not available.  An additional database uncertainty factor (UFDB) due
to lack of neurotoxicity and immunotoxicity studies was not applied
because there is no evidence of neurotoxicity or immunotoxicity.

Inhalation Exposure (Intermediate-Term)

Study Selected:    90-Day Oral Toxicity (dog)

MRID No.:  00162768

Dose and Endpoint for Risk Assessment:  See Section 3.5.3

Comments about Study/Endpoint/Uncertainty Factors:   See Section 3.5.6. 
A default inhalation absorption rate of 100% is assumed relative to oral
absorption, as an inhalation study and/or data on inhalation absorption
are not available.  An additional database uncertainty factor (UFDB) due
to lack of neurotoxicity and immunotoxicity studies was not applied
because there is no evidence of neurotoxicity or immunotoxicity.

3.5.10   Inhalation Exposure (Long-Term)

Long-term inhalation exposure is not anticipated; therefore this risk
assessment is not required.

3.5.11	Level of Concern for Margin of Exposure  TC \l3 "3.5.8	Level of
Concern for Margin of Exposure 

    

        Table 3.   Summary of Levels of Concern for Risk Assessment.

Route	Short-Term

(1 - 30 Days)	Intermediate-Term

(1 - 6 Months)	Long-Term

(> 6 Months)

Occupational (Worker) Exposure

Dermal	100	100	NA

Inhalation	100	100	NA

Residential Exposure

Dermal	100	100	NA

Inhalation	100	100	NA

Incidental Oral	100	100	NA

N/A    Not applicable   Long-term exposures are not anticipated for
flurprimidol, based on current use patterns.

Recommendation for Aggregate Exposure Risk Assessments

There are no food/feed uses for flurprimidol.  Based on the current use
pattern, an aggregate exposure risk assessment is not required.  With
respect to the occupational risk assessment, the dermal and inhalation
exposures should be combined since the same toxicological point of
departure was chosen.  Similarly, incidental oral and dermal
post-application exposures for children in residential settings should
be combined.

3.5.12	Classification of Carcinogenic Potential  TC \l3 "3.5.10
Classification of Carcinogenic Potential 

Flurprimidol is classified as “not likely to be carcinogenic to
humans.”  There was no evidence of increased tumors in the rat or
mouse.  All eight genotoxicity studies were negative.  The mouse study
did not achieve a maximum tolerated dose, but a new study is not
required since there are no food use registrations and no evidence of
carcinogenicity or genotoxicity. 

3.5.13	Summary of Toxicological Doses and Points of Departure for
Flurprimidol for Use in Human Health Risk Assessments

Toxicological doses and points of departure for flurprimidol for use in
human health risk assessments are summarized in Tables 4 and 5. 

  TC \l3 "3.5.11	Summary of Toxicological Doses and Endpoints for
[Chemical] for Use in Human Risk Assessments 

Table 4.   Summary of Toxicological Doses and Points of Departure for
Flurprimidol 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

Acute Dietary   (All Populations)	This risk assessment is not required. 
There are no food/feed uses of flurprimidol.

Chronic Dietary (All Populations)	This risk assessment is not required. 
There are no food/feed uses of flurprimidol.

Incidental Oral Short-Term (1-30 days)	NOAEL = 10 mg/kg/day	UFA= 10x

UFH=10x

	Residential LOC for MOE = 100

	Developmental toxicity oral (gavage) study-  rat (MRID 00147301)

LOAEL = 45 mg/kg/day based on decreased maternal body weight and food
consumption.

Incidental Oral Intermediate-Term (1-6 months)	NOAEL = 1.5 mg/kg/day

	UFA= 10x

UFH=10x

	Residential LOC for MOE = 100

	90-day oral toxicity (diet) - dog (MRID 00162768)

LOAEL = 30 mg/kg/day, based on decreased adrenal weights and
histopathology (increased eosinophilic degeneration and vacuolation in
the zona fasciculata in both sexes; cortical atrophy and eosinophilic
degeneration in the zona reticularis in males).

Dermal          Short- Term (1-30 days)	NOAEL = 10 mg/kg/day

(dermal absorption rate = 6.0% relative to oral absorption)	UFA= 10x

UFH=10x

	Residential LOC for MOE = 100

	Developmental toxicity oral (gavage) study in the rat (MRID 00147301)

LOAEL = 45 mg/kg/day based on decreased maternal body weight and food
consumption and in fetuses, increased incidences of hydronephrosis,
hydroureter, microphthalmia and anomalies in the vertebrae and ribs.

Dermal Intermediate-Term (1-6 months)	NOAEL = 1.5 mg/kg/day.

(dermal absorption rate = 6.0% relative to oral absorption)	UFA= 10x

UFH=10x

	Residential LOC for MOE = 100

	90-day oral toxicity (diet) - dog (MRID 00162768)

LOAEL = 30 mg/kg/day, based on decreased adrenal weights and
histopathology (increased eosinophilic degeneration and vacuolation in
the zona fasciculata in both sexes; cortical atrophy and eosinophilic
degeneration in the zona reticularis in males).

Inhalation       Short-Term (1-30 days)	NOAEL = 10 mg/kg/day

(inhalation absorption rate = 100% relative to oral absorption)	UFA= 10x

UFH=10x

	Residential LOC for MOE = 100	Developmental toxicity oral (gavage)
study in the rat (MRID 00147301)

LOAEL = 45 mg/kg/day based on decreased maternal body weight and food
consumption and in fetuses, increased incidences of hydronephrosis,
hydroureter, microphthalmia and skeletal anomalies in the vertebrae and
ribs.

Inhalation Intermediate-Term (1-6 months)	NOAEL = 1.5 mg/kg/day

(inhalation absorption rate = 100% relative to oral absorption)	UFA= 10

UFH=10

	Residential LOC for MOE = 100

	90-day oral toxicity (diet) - dog (MRID 00162768)

LOAEL = 30 mg/kg/day, based on decreased adrenal weights and
histopathology (increased eosinophilic degeneration and vacuolation in
the zona fasciculata in both sexes; cortical atrophy and eosinophilic
degeneration in the zona reticularis in males).

Cancer (oral, dermal, inhalation)	Classification:  “Not likely to be
carcinogenic to humans.”  This risk assessment is not required.

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).  UFL = use of a LOAEL to extrapolate a NOAEL.  UFS = use
of a short-term study for long-term risk assessment.  UFDB = to account
for the absence of key data (i.e., lack of a critical study).  FQPA SF =
FQPA Safety Factor.  PAD = population adjusted dose (a = acute, c =
chronic).  RfD = reference dose.  MOE = margin of exposure.  LOC = level
of concern.  N/A = not applicable.

Table 5.   Summary of Toxicological Doses and Points of Departure for
Flurprimidol 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-Term (1-30 days)	NOAEL=10 mg/kg/day

(dermal absorption rate relative to oral = 6%)	UFA=10x

UFH=10x

	Occupational LOC for MOE = 100	Developmental toxicity oral (gavage)
study in the rat (MRID 00147301)

LOAEL = 45 mg/kg/day based on decreased maternal body weight and food
consumption and in fetuses, increased incidences of hydronephrosis,
hydroureter, microphthalmia and anomalies in the vertebrae and ribs.

Dermal Intermediate-Term (1-6 months)	NOAEL=1.5 mg/kg/day

(dermal absorption rate relative to oral = 6%)	UFA=10x

UFH=10x

	Occupational LOC for MOE = 100	90-day oral toxicity (diet) - dog (MRID
00162768)

LOAEL = 30 mg/kg/day, based on decreased adrenal weights and
histopathology (increased eosinophilic degeneration and vacuolation in
the zona fasciculata in both sexes; cortical atrophy and eosinophilic
degeneration in the zona reticularis in males).

Inhalation     Short-Term (1-30 days)	NOAEL=10 mg/kg/day

(inhalation absorption rate = 100% relative to oral absorption)	UFA=10x

UFH=10x

	Occupational LOC for MOE = 100	Developmental toxicity oral (gavage)
study in the rat (MRID 00147301)

LOAEL = 45 mg/kg/day based on decreased maternal body weight and food
consumption and in fetuses, increased incidences of hydronephrosis,
hydroureter, microphthalmia and anomalies in the vertebrae and ribs.

Inhalation Intermediate-term (1-6 months)	NOAEL=1.5 mg/kg/day

(inhalation absorption rate = 100% relative to oral absorption)	UFA=10x

UFH=10x

	Occupational LOC for MOE = 100	90-day oral toxicity (diet) - dog (MRID
00162768)

LOAEL = 30 mg/kg/day, based on decreased adrenal weights and
histopathology (increased eosinophilic degeneration and vacuolation in
the zona fasciculata in both sexes; cortical atrophy and eosinophilic
degeneration in the zona reticularis in males).

Cancer (oral, dermal, inhalation)	Classification:  “Not likely to be
carcinogenic to humans.”  This risk assessment is not required.

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).  UFL = use of a LOAEL to extrapolate a NOAEL.  UFS = use
of a short-term study for long-term risk assessment.  UFDB = to account
for the absence of key data (i.e., lack of a critical study).  MOE =
margin of exposure.  LOC = level of concern.  N/A = not applicable.

3.6	Endocrine disruption  TC \l2 "3.6	Endocrine disruption 		

EPA is required under the FFDCA, as amended by FQPA, to develop a
screening program to determine whether certain substances (including all
pesticide active and other ingredients) “may have an effect in humans
that is similar to an effect produced by a naturally occurring estrogen,
or other such endocrine effects as the Administrator may designate.” 
Following recommendations of its Endocrine Disruptor Screening and
Testing Advisory Committee (EDSTAC), EPA determined that there was a
scientific basis for including, as part of the program, the androgen and
thyroid hormone systems, in addition to the estrogen hormone system. 
EPA also adopted EDSTAC’s recommendation that the Program include
evaluations of potential effects in wildlife.  For pesticide chemicals,
EPA will use FIFRA and, to the extent that effects in wildlife may help
determine whether a substance may have an effect in humans, FFDCA
authority, to require the wildlife evaluations.  As the science develops
and resources allow, screening of additional hormone systems may be
added to the Endocrine Disruptor Screening Program (EDSP).

When additional appropriate screening and/or testing protocols being
considered under the Agency’s EDSP have been developed, flurprimidol
may be subjected to further screening and/or testing to characterize
more fully the effects related to endocrine disruption.

4.0  Product Use information/Application Timing tc \l1 "3.0  Product Use
information/Application Timing 

Proposed use patterns for flurprimidol are summarized in Table 6.

Table 6.  Proposed Use Patterns for flurprimidol.

Crop 

 	

Product, Formulation	

Treatment Type	

Applications Per Season 1  	

Maximum Application Rate2

(lb ai/acre) 

Per Application	

Per Season

Occupational Uses (By LCO only)

Turfgrasses	Cutless 50W             Turf Growth Regulator, Wettable
Power            in Water-Soluble Bags	Ground-boom

Handgun	Multiple        (Trt Interval:      3~6 wks)	1.5	3

Turfgrasses	SP5075                          Turf Growth Regulator,
Liquid	Ground-boom  Handgun	Multiple        (Trt Interval:      2~6 wks)
	0.26	12

Turfgrasses	Turf Fertilizer-Contains Cutless 0.375%,            
Granules	Tractor-Drawn Spreader   Push-Type Spreader         
Belly-Grinder	2	1.5	3

Turfgrasses	Turf Fertilizer-Contains Cutless 0.17%,             Granules
Tractor-Drawn Spreader   Push-Type Spreader          Belly-Grinder	3	1.5
3

Residential Use 

Turfgrasses	Turf Fertilizer-Contains Cutless 0.375%,            
Granules	Push-Type Spreader          Belly-Grinder                   
Dispersed by Hand 	2	1.5	3

Turfgrasses	Turf Fertilizer-Contains Cutless 0.17%,             Granules
Push-Type Spreader          Belly-Grinder                    Dispersed
by Hand 	3	1.5	3

Woody Ornamental Plants & Perennial Ground Covers	Cutless 0.33G         
       Landscape           Growth Regulator,          Granules	Push-Type
Spreader  Belly Grinder                    Dispersed by Hand	Not
Available	1	Not Available

1 Maximum number of applications allowed on label.

2 Rate = Maximum application rates as specified on proposed labels.

According to the labels, the proposed flurprimidol products are applied
when rainfall is expected within a few days, or irrigation is required
within a few days after turf is treated to move flurprimidol down into
the root zone and soil to achieve its intended growth-regulating effect.

5.0   Residential/Non-Occupational Exposure

5.1        Handlers 

Among the five products, only Cutless 0.33G Landscape Growth Regulator
and Turf Fertilizers (both 0.17% & 0.375% products) are proposed for
homeowner applications.  Residents will be exposed to flurprimidol when
they apply those products around their home, therefore,
residential/non-occupational handler’s exposure/risk assessment is
required.

 

Exposure Scenarios

There are three handler scenarios that are expected to result in the
highest exposure for the proposed uses:

Mixing/Loading/Applying Granules with a Belly Grinder (Scenario 1)

Mixing/Loading/Applying Granules with a Push-Type Granular Spreader
(Scenario 2)

Mixing/Loading/Applying Granules--Dispersed by Hand for Spot Treatment
(Scenario 3)

Equations/Calculations

The following equations were used to calculate handler exposure and
risk:

Dermal Dose (mg/kg/day) 	=	Rate (lb ai/A) x UE (mg/lb ai) x DA x Acres
Treated (A/day)

BW (kg)

Inhalation Dose (mg/kg/day)	=	 Rate (lb ai/acre) x UE (mg/lb ai) x Acres
Treated (A/day)

        BW (kg)

Where:

Rate (Application Rate)		=	Maximum application rate on product label (lb
ai/acre)

UE (Unit Exposure)		=	Exposure value derived from August 1998 PHED
Surrogate Exposure Table (mg/lb ai handled)

DA (dermal absorption factor)	=	Factor to account for dermal absorption
(6%) when POD is selected from an oral study.

Acres Treated			=	Maximum number of acres treated per day (acres/day)

              BW				=	Body weight (kg)

Combined Daily Dose (mg/kg/day) 	=	Dermal Dose (mg/kg/day) + Inhalation
Dose (mg/kg/day)

MOE     	                                           =	NOAEL (10
mg/kg/day)               

                                                                        
             Combined Daily Dose (mg/kg/day)

Application Rate

The maximum application rates listed on the proposed label provided by
the Registration Division were used for this exposure assessment. 

The maximum rates are 1.0 lb ai/A for Cutless 0.33G Landscape Growth
Regulator and 1.5 lb ai/A for Turf Fertilizers.  The residential
handler’s exposure assessment is performed for Turf Fertilizers’
applicators because they have higher application rates.

Area or the Amount Treated

Based on HED’s Residential SOP, 0.5 acre/day for application using
Belly Grinder or Push-Type Spreader, or 1000 ft² (0.023 acre)/day for
hand-application (granules are dispersed by hand).

Body Weight									

The female body weight (60 kg) was used because the short-term PODs are
from a development study.

Exposure Frequency

No data on the number of exposure days per year were provided   For this
risk assessment, it was assumed that residential/non-occupational
handlers would be exposed for less than 30 days per year (short-term
exposures).    

Unit Exposures

The unit exposures for Belly Grinder and hand applications are based on
the PHED Version 1.1 as presented in the August 1998 PHED Surrogate
Exposure Guide.  The unit exposures for Push-Type Spreader are based on
those provided by the Outdoor Residential Exposure Task Force (ORETF) as
shown in the 3/5/03 review of ORETF data by G. Bangs.

●   Loading/Applying granules using Belly Grinder: 10 mg/lb ai
(dermal; single layer, no gloves)        and 62 µg/lb ai (inhalation);

●   Loading/Applying granules with hand application:  71 mg/lb ai
(dermal; single layer + gloves)      and 470 µg/lb ai (inhalation);

●   Loading/Applying granules using Push-Type Spreader:  0.67 mg/lb ai
(dermal; long pants/             short sleeves, no gloves) and 0.88
µg/lb ai (inhalation).  These ORETF unit exposures are         based on
90th % statistical level. 

Handlers’ Exposure and Risk

  

The MOEs for residential handlers performing Turf Fertilizers
applications using Belly Grinder, Push-Type Spreader, and hand
application are 1,200, 20,000, and 3,700 respectively.  These MOEs are
greater than 100 and do not exceed HED’s level of concern.  A summary
of the exposures/risks for residential handlers is presented in Table 7.

The exposure/risk for residential handlers performing Cutless 0.33G
application shall be no greater than those estimated for Turf
Fertilizers applications because the application rate for Cutless 0.33G
use is lower than those for Turf Fertilizers’ applications, and both
products are granules.

The residential handler exposure estimates in this assessment are based
on a central tendency estimate of unit exposure and an upper-percentile
assumption for the application rate, and are assumed to be
representative of high-end exposures.  The uncertainties associated with
this assessment stem from the use of surrogate exposure data (e.g.,
differences in use scenario and data confidence), and assumptions
regarding that amount of chemical handled.  The estimated exposures are
believed to be reasonable high-end estimates based on observations from
field studies and professional judgement.

Table 7.  Short-Term Non-Cancer Risk for Residential Turf Fertilizer
Handlers

Exposure Scenario (Scenario #)	

Dermal Unit Exposurea (mg/lb ai)	

Inhalation Unit Exposureb (µg/lb ai)	

Amount Treatedc

(A/day)	

Daily

Dermal

Dosed (mg/kg/day)	

Daily

Inhalation

Dosee (mg/kg/day)	

Combined

Daily Dosef (mg/kg/day)	

MOEg  

Mixing/Loading/Applying Granules with a Belly Grinder	10              no
gloves  (PHED) 	62              (PHED) 	0.5	0.0075	0.00078	0.00828	1,200

Mixing/Loading/Applying Granules with a Push-Type Granular Spreader	0.67
          no gloves  

(ORETF)	0.88

(ORETF)	0.5	0.0005	0.000011	0.000511	20,000

Mixing/Loading/Applying Granules--Dispersed by Hand	71              +
gloves  (PHED) 	470            (PHED)  	0.023	0.00245	0.00027	0.00272
3,700

a.	PHED Baseline Dermal Unit Exposure represents long pants, long
sleeved shirt, no gloves, open mixing/loading, and open cab tractors, as
appropriate.  ORETF Baseline Dermal Exposure represents long pants and
short sleeves.

b.	PHED Baseline Inhalation Exposure represents no respiratory
protection, open mixing/loading, and open cab tractors, as appropriate. 
ORETF Baseline Inhalation Exposure represents no respiratory protection,
open mixing/loading.  

c.	Daily acres treated values are from EPA estimates of acreage that
could be treated or volume handled in a single day for each exposure
scenario of concern, based on the application method and
formulation/packaging type.

d.	Daily dermal dose (mg/kg/d) =  [unit dermal exposure (mg/lb ai) *
dermal absorption (0.06) * application rate (1.5 lb ai/acre) * daily
acres treated /  body weight (60 kg).

e.	Daily inhalation dose (mg/kg/d) = (unit exposure (µg/lb ai) *
(1mg/1000 µg) conversion * application rate (1.5 lb ai/acre) * daily
acres treated / body weight (60 kg).

f.	Combined daily dose = daily dermal dose + daily inhalation dose.

g.	MOE = NOAEL (10 mg/kg/d) / combined daily dose.  UF = 100.

	

Post-application 

Adult and children residents may be exposed to flurprimidol residues on
the turf following the applications of Cutless 50W, SP5075 and Turf
Fertilizers containing Cutless.  Although Cutless 0.33 G is applied to
perennial groundcover and landscape ornamental plants, the potential for
exposure to flurprimidol foliar residues is very limited, and is
believed to be much less than that for turf use products.  Therefore, a
separate assessment for exposure from ornamentals was not conducted.  

Exposure Scenarios

There are 6 post-application scenarios that are expected to result in
the highest exposure for the proposed uses:

Post-application Dermal Exposure—Short-Term (Scenario 1)

Post-application Incidental Oral Exposure—Hand to Mouth (Scenario 2)

Post-application Incidental Oral Exposure—Object to Mouth (Scenario 3)

Post-application Incidental Oral Exposure—Soil Ingestion (Scenario 4)

Post-application Incidental Oral Exposure—Ingestion of Pesticide
Granules (Scenario 5)

Post-application Dermal Exposure—Golfer (Scenario 6)

Equations/Calculations

The following equations were used to calculate post-application exposure
and risk:

TTR (mg/cm2)		= AR (lb ai/acre) x F x 4.54E8 µg/lb x 24.7E-9 acre/cm2  
x 1E-3 mg/µg 

Where:

TTR	  =	turf transferable residue (mg/cm2)

AR	=	application rate (lb ai/acre)

F	=	fraction of ai retained on foliage (unitless)

Chemical specific data on foliar residues of flurprimidol are available
(Moran et al., 1987, MRID 40184414).  This study has been reviewed by
HED (D. Jaquith, 3/1/90).  The residue data were generated by washing
grass clippings with distilled water containing Turgitol as a
surfactant.  The study indicates that the residues found at 1 and 6 days
after treatment correspond to 13-14% of the application rate.  At 1 day
after treatment (DAT) (i.e., post-irrigation) residues decreased to 1.6%
of the application rate and by 17 DAT were down to 0.03% of the rate. 
The corresponding half-life of the residues was 3.2 days.

HED does not consider the foliar residue data generated in the above
study appropriate for assessing dermal or hand-to-mouth exposures from
the use of flurprimidol on turf.  Use of the surfactant rinse would be
more appropriate for predicting dislodgeable foliar residues (DFR)(i.e.,
those needed to assess post-application exposure to agricultural crops)
than the turf transferrable residues (TTR) needed to assess the proposed
flurprimidol uses.  Therefore, the TTR for the present assessments will
be based on HED’s default values (5% for dermal and hand-to-mouth
exposures, 20% for object-to-mouth).

For this short-term residential exposure assessment, the day zero
default value of 5% of the application rate is assumed.  This assumption
is very conservative because it implies that residents will always enter
the treated areas immediately following application.  According to the
label, irrigation is required within 24 hours after turf is treated to
move flurprimidol down into the root zone and soil to achieve its
intended growth-regulating effect.  The irrigation procedure would
significantly reduce the available residues on turf as shown by the
chemical specific study where
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●    Post-Application Dermal Exposure

ADD (mg/kg/day)          = TTR (mg/cm2) x Tc (cm2/hr) x ET (hrs) x DA /
BW (kg)

Where:

ADD    =           Average Daily Dose (mg/kg/day)          

TTR	=	turf transferable residue (mg/cm2); = 5% of application rate

Tc	=	transfer coefficient (Short-term: 14,500 cm2/hr for adult, 5,200
cm2/hr for child; Intermediate-term: 7,300 cm2/hr for adult, 2,600 for
child; HED Residential SOP) 

ET	=	exposure time (2 hr/day)

DA	=	dermal absorption factor (unitless, 6%)

BW	=	body weight (Short-term: 60 kg for adult, 15 kg for child;
Intermediate-term: 70 kg for adult, 15 kg for child)

MOE     	               =	NOAEL (10 or 1.5 mg/kg/day)               

                                                                    ADD
(mg/kg/day)

●    Post-application Incidental Oral Exposure—Hand to Mouth

ADD (mg/kg/day)          = TTR (mg/cm2) x SA (cm2/event) x FQ (event/hr)
x ET (hr/day) x SF (0.5) 

                                                                        
              BW (kg)

Where:

ADD    =           Average Daily Dose (mg/kg/day)          

TTR	=	turf transferable residue (mg/cm2); = 5% of application rate

SA	=	surface area of the hand (20 cm2/event; HED Residential SOP) 

FQ	=	frequency of the hand-to mouth activity (20 event/hr for
short-term, 9.5 event/hr for intermediate-term; HED Residential SOP)

ET	=	exposure time (2 hr/day)

SF        =           Saliva extraction factor (50%)

BW	=	body weight (15 kg)

MOE     	              =	NOAEL (10 or 1.5 mg/kg/day)               

                                                                    ADD
(mg/kg/day)

●    Post-application Incidental Oral Exposure—Object to Mouth

ADD (mg/kg/day)          = TTR (mg/cm2) x IgR (cm2/day)  

                                                           BW (kg)

Where:

ADD    =           Average Daily Dose (mg/kg/day)          

TTR	=	turf transferable residue (mg/cm2); = 20% of application rate

IgR	=	ingestion rate of grass (25 cm2/day; HED Residential SOP) 

BW	=	body weight (15 kg)

MOE     	
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●    Post-application Incidental Oral Exposure—Soil Ingestion

ADD (mg/kg/day)          = SR (µg/g) x IgR (mg/day) x CF1 

                                                             BW (kg)

SR (µg/g)                     = AR x F x CF2 x CF3 x CF4

Where:

ADD    =           Average Daily Dose (mg/kg/day)          

SR	=	Soil residue (µg/g) 

IgR       =           ingestion rate of soil (100 mg/day; HED
Residential SOP) 

BW	=	body weight (15 kg)

AR	=	application rate (lb ai/acre)

            F          =            fraction of a.i. available in
uppermost cm of soil (100%/cm; HED Residential                          
                    SOP)

            CF2      =            weight unit conversion factor (4.54 E8
µg/lb; HED Residential SOP)                                 CF3      = 
          area unit conversion factor (2.47 E-8 acre/cm2; HED
Residential SOP)      

           CF4      =            volume to weight unit conversion factor
(0.67 cm3/g soil; HED Residential SOP)     

MOE     	                   
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●    Post-application Incidental Oral Exposure—Ingestion of
Pesticide Granules

ADD (mg/kg/day)          = IgR (mg/day) x F x CF1 

                                                      BW (kg)

Where:

ADD    =           Average Daily Dose (mg/kg/day)          

IgR       =           ingestion rate (0.3 g/day; HED Residential SOP) 

F	=           fraction of a.i. in dry formulation (0.375%; based on Turf
Fertilizer—contains Cutless 0.375% label))

CF1      =            weight unit conversion factor (1,000
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●    Post-Application Dermal Exposure for Short-Term Golfing

ADD (mg/kg/day)          = TTR (mg/cm2) x Tc (cm2/hr) x ET (hrs) x DA /
BW (kg)

Where:

ADD    =           Average Daily Dose (mg/kg/day)          

TTR	=	turf transferable residue (mg/cm2); = 5% of application rate

Tc	=	transfer coefficient (Short-term: 500 cm2/hr) 

ET	=	exposure time (4 hr/day)

DA	=	dermal absorption factor (unitless, 6%)

BW	=	body weight (Short-term: 60 kg for adult)

MOE     	               =	NOAEL (10 or 1.5 mg/kg/day)               

                                                                    ADD
(mg/kg/day)

Application Rate

The maximum application rates listed on the proposed labels provided by
the Registration Division are 1.0 lb ai/A for Cutless 0.33G Landscape
Growth Regulator, 1.5 lb ai/A for Cutless 50W Turf Growth Regulator, 1.5
lb ai/A for Turf Fertilizer-Contains Cutless 0.375%, 1.5 lb ai/A for
Turf Fertilizer-Contains Cutless 0.17%, and 0.26 lb ai/A for SP5075 Turf
Growth Regulator.  The highest rate of 1.5 lb ai/A was used for this
residential post-application assessment.

Exposure Frequency

For this residential post-application risk assessment, it was assumed
that adult and child residents would be exposed for less than 30 days
per year (short-term exposures) because it is not common that those
activities would last continuously for more than 30 days.  

Post-Application Exposure and Risk

All post-application MOEs for adult and child residents (based on
exposures following the application of Cutless 50W Turf Growth Regulator
at 1.5 lb ai/A) are greater than 100 (130 ~ 130,000) and therefore do
not exceed HED’s level of concern.  Summaries of the residential
post-application exposures/risks are presented in Table 8.

The residential post-application exposures/risks resulting from the uses
of Cutless 0.33G Landscape Growth Regulator, Turf Fertilizer-Contains
Cutless 0.375%, Turf Fertilizer-Contains Cutless 0.17%, or SP5075 Turf
Growth Regulator shall be no greater than those estimated for the use of
Cutless 50W Turf Growth Regulator because their application rates are
lower than that for Cutless 50W Turf Growth Regulator (1.5 lb ai/A). 

Table 8.  Residential Post-application Exposure and Risk

Applied Product	

Application Rate 

(lb ai/A)	

Post-Application Scenarios	

Fraction of ai retained a (%)	

TTRb   

(mg/cm2)	

SRc

(µg/g)	

Average Daily Dosed (mg/kg/day)	

 MOE e 

Cutless 50W Turf Growth Regulator	1.5

	Dermal—

Short-Term (S-T) 	5	0.000841

A=0.0244

C=0.0350	A=410

C=290

Incidental Oral—

Hand to Mouth (S-T)	5	0.000841

C=0.0224	C=450

Incidental Oral—

Object to Mouth (S-T)	20	0.00336

C=0.0056	C=1,800

Incidental Oral—

Soil Ingestion (S-T)

	11.4	C=0.000075	C=130,000

Incidental Oral— Granules Ingestion (S-T)

C=0.075	C=130

Dermal—Golfing

Short-Term (S-T)	5	0.000841

A=0.001682	A=5,900

a.	Fraction of ai retained on foliage (unitless)

b.	TTR (mg/cm2) = AR (lb ai/acre) x F x 4.54E8 µg/lb x 24.7E-9 acre/cm2
  x 1E-3 mg/µg 

c.	SR (µg/g) = AR x F x CF2 x CF3 x CF4

d.	ADD (mg/kg/day) = TTR (mg/cm2) x Tc (cm2/hr) x ET (hrs) x DA / BW
(kg), or ADD (mg/kg/day) = TTR (mg/cm2) x SA (cm2/event)                
   x FQ (event/hr) x ET (hr/day) x SF (0.5) / BW (kg), or ADD
(mg/kg/day) = TTR (mg/cm2) x IgR (cm2/day) / BW (kg), or ADD            
                  (mg/kg/day) = SR (µg/g) x IgR (mg/day) x CF1 / BW
(kg), or ADD (mg/kg/day) = IgR (mg/day) x F x CF1 / BW (kg); A=Adult,
C=Child. 

e.	MOE = NOAEL (10 mg/kg/day) / ADD (mg/kg/day); A=Adult, C=Child. 

The aggregate MOE for child’s exposures (hand-to-mouth + dermal) is
170 which does not exceed HED’s level of concern.  

The exposure values generated using HED Residential SOP are based on
some central tendency and some upper-percentile assumptions and are
considered to be representative of high-end exposures.  These exposure
estimates are considered to be reasonable high-end estimates based on
professional judgement. 

6.0        Occupational Exposure

6.1        Handlers 

Based on the information provided in the labels, occupational handlers
are expected to apply proposed products in the residential settings.

Exposure Scenarios

There are 9 handler scenarios that are expected to result in the highest
exposure for the proposed uses:

Mixing/Loading Wettable Powder (WSP) for Ground-boom Applications
(Scenario 1)

Mixing/Loading Liquid for Ground-boom Applications (Scenario 2)

Mixing/Loading Granules for Tractor-Drawn Spreader Application (Scenario
3)

Applying Sprays with Ground-boom Equipment (Scenario 4)

Applying Granules with Tractor-Drawn Spreader (Scenario 5)

Mixing/Loading/Applying Wettable Powder (WSP) with Handgun (Scenario 6)

Mixing/Loading/Applying Liquid with Handgun (Scenario 7)

Loading/Applying Granules with Push-Type Spreader (Scenario 8)

Loading/Applying Granules with Belly-Grinder (Scenario 9)

Equations/Calculations

The following equations were used to calculate handler exposure and
risk:

Dermal Dose (mg/kg/day) 	=	Rate (lb ai/A) x UE (mg/lb ai) x DA x Acres
Treated (A/day)

BW (kg)

Inhalation Dose (mg/kg/day)	=	 Rate (lb ai/acre) x UE (mg/lb ai) x Acres
Treated (A/day)

        BW (kg)

Where:

Rate (Application Rate)		=	Maximum application rate on product label (lb
ai/acre)

UE (Unit Exposure)		=	Exposure value derived from August 1998 PHED
Surrogate Exposure Table (mg/lb ai handled)

DA (dermal absorption factor)	=	Factor to account for dermal absorption
(6%) when POD is selected from an oral study.

Acres Treated			=	Maximum number of acres treated per day (acres/day)

              BW				=	Body weight (kg)

Combined Daily Dose (mg/kg/day) 	=	Dermal Dose (mg/kg/day) + Inhalation
Dose (mg/kg/day)

MOE     	                                           =	NOAEL (10 or 1.5
mg/kg/day)               

                                                                        
             Combined Daily Dose (mg/kg/day)

Application Rate  

The maximum application rates listed on the proposed labels provided by
the Registration Division are 1.0 lb ai/A for Cutless 0.33G Landscape
Growth Regulator, 1.5 lb ai/A for Cutless 50W Turf Growth Regulator, 1.5
lb ai/A for Turf Fertilizer-Contains Cutless 0.375%, 1.5 lb ai/A for
Turf Fertilizer-Contains Cutless 0.17%, and 0.26 lb ai/A for SP5075 Turf
Growth Regulator. 

Area or the Amount Treated

Based on HED’s Exposure Science Advisory Council (Expo SAC) Policy
Number 9.1, following application capacities were assumed: 80 acres/day
for application using ground-boom equipment,  5 acres/day for
application using handgun, 40 acres/day for application using
Tractor-Drawn Spreader, 5 acres/day for application using push-type
spreader, and 1 acre/day for application using belly-grinder.

Body Weight									

The female body weight (60 kg) was used for short-term assessment
because the short-term PODs are from a development study.  The average
body weight for general population (70 kg) was used for
intermediate-term assessment.

Exposure Frequency

No data on the number of exposure days per year was provided.  For this
risk assessment, it was assumed that handlers would be exposed for less
than 6 months per year (short- and intermediate-term exposures). 
Long-term exposures are not expected.  

Unit Exposures

The unit exposures are based on the PHED Version 1.1 as presented in the
August 1998 PHED Surrogate Exposure Guide (Scenarios 1~5 and Scenario
9), ORETF unit exposures (Scenarios 6~8), and are also based on a
chemical-specific exposure study (Scenarios 1 and 4).

For PHED unit exposures, there are three basic risk mitigation
approaches considered appropriate for controlling occupational
exposures.  These include administrative controls, the use of personal
protective equipment or PPE, and the use of engineering controls. 
Occupational handler exposure assessments may be completed by HED using
baseline, PPE, and engineering controls. [Note: Administrative controls
available generally involve altering application rates for handler
exposure scenarios.  These are typically not utilized for completing
handler exposure assessments.] The baseline clothing level scenario for
occupational exposure scenarios is generally an individual wearing long
pants, a long-sleeved shirt, no chemical resistant gloves, and no
respirator.  The first level of mitigation generally applied is PPE. 
PPE may involve the use of an additional layer of clothing,
chemical-resistant gloves, and a respirator.  The next level of
mitigation considered in the risk assessment process is the use of
appropriate engineering controls which, by design, attempt to eliminate
the possibility of human exposure.  The assessments in this document
were done at the baseline level or at baseline level plus gloves as PPE.
                                   

 

For ORETF unit exposures, the handlers are assumed to wear long pants,
short sleeves, with no gloves.  These unit exposures are based on 90th %
statistical level.

A chemical specific exposure study was conducted in which exposures to
handlers mixing/loading and applying Cutless 50W to golf courses were
measured (Day, 1987, MRID 40184415).  Based on this study, the unit
exposures for handlers wearing long pants and short-sleeved
桳物獴愠敲ഺ

●     Mixing/loading wettable powder formulations in water soluble
bags:  0.0227 mg/lb ai 

        (dermal) and 0.726 µg/lb ai (inhalation); and

●     Applying liquid sprays with ground-boom:  0.0639 mg/lb ai
(dermal) and 0.455 µg/lb ai 

        (inhalation).

Handlers’ Exposure and Risk

Except the intermediate-term MOE for mixing/loading liquid for
ground-boom application, all other MOEs for occupational handlers
performing proposed uses are greater than 100 (110 ~ 3,300) at the
baseline level (single layer, no gloves).  The intermediate-term MOE for
mixing/ loading liquid for ground-boom application is 29 at single
layer/no gloves level, but the MOE increases to 2,000 at single layer
plus gloves level.  These MOEs do not exceed HED’s level of concern
(MOE > 100).  Summaries of the exposures/risks for occupational handlers
are presented in Tables 9 and 10.

The handler exposure estimates in this assessment are based on a central
tendency estimate of unit exposure and an upper-percentile assumption
for the application rate, and are assumed to be representative of
high-end exposures.  The uncertainties associated with this assessment
stem from the use of surrogate exposure data (e.g., differences in use
scenario and data confidence), and assumptions regarding that amount of
chemical handled.  The estimated exposures are believed to be reasonable
high-end estimates based on observations from field studies and
professional judgement.

6.2        Post-application  

Based on the proposed use pattern, occupational workers will be exposed
to flurprimidol when they enter the sites to work (irrigation, weeding
etc.) after turf is treated.  tc \l2 "5.1   For Crop Protection Uses  
5.1.1.  Handlers  

Equations/Calculations

The following equations were used to calculate post-application exposure
and risk:

Daily dermal dose t	=	TTRt (µg/cm2) x 1E-3 mg/µg x Tc (cm2/hr) x DA x
ET (hrs)

  BW (kg)

Where:

t	=	number of days after application day (days)

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

Tc	=	transfer coefficient (cm2/hr)

DA	=	dermal absorption factor (unitless)

ET	=	exposure time (hr/day)

BW	=	body weight (kg)

TTR (mg/cm2)		= AR (lb ai/acre) x F x 4.54E8 µg/lb x 24.7E-9 acre/cm2  
x 1E-3 mg/µg 

Where:

TTR	  =	turf transferable residue (mg/cm2)

AR	=	application rate (lb ai/acre)

F	=	fraction of ai retained on foliage (unitless; 5%)

As discussed in Section 5.2 (residential post-application), HED does not
consider the chemical specific study appropriate for assessing dermal
exposures to turf residues.  The default value of 5% of the application
rate will also be used for the occupational post-application
assessments.   This assumption is very conservative for both the short-
and intermediate-term assessments because it implies that workers will
always enter the treated areas immediately following application. 
According to the label, irrigation is required within 24 hours after
turf is treated.  Therefore, exposures from that time forward would be
significantly less than those encountered on the day of application.

Post-application Activities and Transfer Coefficients

Anticipated post-application activities and their respective dermal
transfer coefficients (TCs) are summarized in Table 11.  The information
in the table is based on the Expo SAC Policy Number 3.1 and is based on
proprietary and non-proprietary data.

Application Rate

The maximum application rates listed on the proposed labels provided by
the Registration Division are 1.0 lb ai/A for Cutless 0.33G Landscape
Growth Regulator, 1.5 lb ai/A for Cutless 50W Turf Growth Regulator, 1.5
lb ai/A for Turf Fertilizer-Contains Cutless 0.375%, 1.5 lb ai/A for
Turf Fertilizer-Contains Cutless 0.17%, and 0.26 lb ai/A for SP5075 Turf
Growth Regulator. The highest rate of 1.5 lb ai/A was used for this
occupational post-application assessment.

Exposure Frequency

No data on the number of exposure days per year was provided.  For this
risk assessment, it was assumed that post-application workers would be
exposed for less than 6 months per year (i.e., short- and
intermediate-term duration).  

Exposure Duration

Workers were assumed to be exposed 8 hours per day.

Body Weight

The female body weight (60 kg) was used for short-term assessment
because the short-term PODs are from a development study.  The average
body weight for general population (70 kg) was used for
intermediate-term assessment.

Post-application Exposure and Risk

Summaries of the post-application exposures and risks are presented in
Tables 12 and 13.  The short-term MOEs are 440 and 3000 and are not of
concern.  The intermediate-term MOE for irrigation and weeding (450) is
also not of concern.  Although the intermediate-term MOE for course
maintenance is less than 100 (MOE=66), HED is not concerned since the
assessment assumes zero day residues every day and therefore greatly
overestimates exposure, especially considering the irrigation that is
required within a day of application.



 Table 9.  Short-Term Non-Cancer Risk for Occupational Handlers

Exposure Scenario (Scenario #)	

Mitigation Levela	

Dermal Unit Exposureb (mg/lb ai)	

Inhalation Unit Exposurec (µg/lb ai)	

Crop	

Application Rate

(lb ai/A)	

Amount Treatedd

(A/day)	

Daily

Dermal

Dosee (mg/kg/day)	

Daily

Inhalation

Dosef (mg/kg/day)	

Combined

Daily Doseg (mg/kg/day)	

MOEh  

Mixer/Loader

Wettable Powder (WSP) for Ground-boom for 

ground-boom (1)---a	Single layer no gloves	0.021

(PHED)	0.24

(PHED)	Turf	1.5	80	0.00252	0.00048	0.003	3,300

Wettable Powder (WSP) for Ground-boom for 

ground-boom (1)---b	long pants short sleeve	0.0227 

(Day 1987)	0.726

(Day 1987)	Turf	1.5	80	0.002724	0.001452	0.004176	2,400

Liquid 

for Ground-boom (2)	Single layer no gloves	2.9

(PHED)	1.2

(PHED)	Turf	0.26	80	0.06032	0.000416	0.060736	170

Granules for Tractor-Drawn Spreader (3)	Single layer no gloves	0.0084

(PHED)	1.7

(PHED)	Turf	1.5	80	0.001008	0.0034	0.004408	2,300

Applicator

Sprays with                   Ground-boom (4)---a	Single layer no gloves
0.014

(PHED)	0.74

(PHED)	Turf	1.5	80	0.00168	0.001479	0.003159	3,200

Sprays with                   Ground-boom (4)---a	Single layer no gloves
0.014

(PHED)	0.74

(PHED)	Turf	0.26	80	<0.00168	<0.001479	<0.003159	>3,200

Sprays with                   Ground-boom (4)---b	long pants short
sleeve	0.0639

(Day 1987)	0.455

(Day 1987)	Turf	1.5	80	0.00768	0.000909	0.008589	1,200

Sprays with                   Ground-boom (4)---b	long pants short
sleeve	0.0639

(Day 1987)	0.455

(Day 1987)	Turf	0.26	80	<0.00768	<0.000909	<0.008589	>1,200

Granules with Tractor-Drawn Spreader (5)	Single layer no gloves	0.0099 

(PHED)	1.2

(PHED)	Turf	1.5	80	0.001188	0.0024	0.003588	2,800

Mixer/Loader/Applicator

Wettable Powder (WSP) with Handgun (6)	Single layer +gloves	1.2         
   (ORETF) 	43              (ORETF) 	Turf	1.5	5	0.009	0.005375	0.014375
700

Liquid with                    Handgun (7)	Single layer +gloves	2.4     
       (ORETF) 	3.4             (ORETF) 	Turf	0.26	5	0.018	0.000425
0.003825	2,600

Granules with        Push-Type Spreader (8)	long pants short sleeve	0.67

(ORETF)	0.88

(ORETF)	Turf	1.5	5	0.005	0.00011	0.00511	2,000

Granules with        Belly-Grinder (9)	Single layer no gloves	10        
     (PHED) 	62              (PHED) 	Turf	1.5	1	0.015	0.001545	0.016545
600

a	Baseline consists of long-sleeve shirt, long pants, shoes, and socks
and no respirator.  PPE consists of long-sleeve shirt, long pants,
shoes, socks, chemical-resistant gloves, and no respirator.

b	Baseline Dermal Unit Exposure represents long pants, long sleeved
shirt, no gloves, open mixing/loading, and open cab tractors, as
appropriate.  

c	Baseline Inhalation Exposure represents no respiratory protection,
open mixing/loading, and open cab tractors, as appropriate.  

d	Daily acres treated values are from EPA estimates of acreage that
could be treated or volume handled in a single day for each exposure
scenario of concern, based on the application method and
formulation/packaging type.

e	Daily dermal dose (mg/kg/d) =  [unit dermal exposure (mg/lb ai) *
dermal absorption (0.06) * application rate (lb ai/acre) * daily acres
treated /  body weight (60 kg).

f	Daily inhalation dose (mg/kg/d) = (unit exposure (µg/lb ai) *
(1mg/1000 µg) conversion * application rate (lb ai/acre) * daily acres
treated / body weight (60 kg).

g	Combined daily dose = daily dermal dose + daily inhalation dose.

h	MOE = NOAEL (10 mg/kg/d) / combined daily dose.  UF = 100.

Table 10.  Intermediate-Term Non-Cancer Risk for Occupational Handlers

Exposure Scenario (Scenario #)	

Mitigation Levela	

Dermal Unit Exposureb (mg/lb ai)	

Inhalation Unit Exposurec (µg/lb ai)	

Crop	

Application Rate

(lb ai/A)	

Amount Treatedd

(A/day)	

Daily

Dermal

Dosee (mg/kg/day)	

Daily

Inhalation

Dosef (mg/kg/day)	

Combined

Daily Doseg (mg/kg/day)	

MOEh  

Mixer/Loader

Wettable Powder (WSP) for Ground-boom for 

ground-boom (1)---a	Single layer no gloves	0.021

(PHED)	0.24

(PHED)	Turf	1.5	80	0.00216	0.000411	0.002571	580

Wettable Powder (WSP) for Ground-boom for 

ground-boom (1)---b	long pants short sleeve	0.0227 

(Day 1987)	0.726

(Day 1987)	Turf	1.5	80	0.00234	0.001245	0.003585	420

Liquid 

for Ground-boom (2)	Single layer no gloves	2.9

(PHED)	1.2

(PHED)	Turf	0.26	80	0.0517	0.000357	0.052057	29

Liquid 

for Ground-boom (2)	Single layer +gloves 	0.023

(PHED)	1.2

(PHED)	Turf	0.26	80	0.000407	0.000357	0.000764	2,000

Granules for Tractor-Drawn Spreader (3)	Single layer no gloves	0.0084

(PHED)	1.7

(PHED)	Turf	1.5	80	0.000864	0.002914	0.003778	400

Applicator

Sprays with                   Ground-boom (4)---a	Single layer no gloves
0.014

(PHED)	0.74

(PHED)	Turf	1.5	80	0.00144	0.001269	0.002709	550

Sprays with                   Ground-boom (4)---a	Single layer no gloves
0.014

(PHED)	0.74

(PHED)	Turf	0.26	80	0.000248	0.000218	0.000466	3,200

Sprays with                   Ground-boom (4)---b	long pants short
sleeve	0.0639

(Day 1987)	0.455

(Day 1987)	Turf	1.5	80	0.00657	0.00078	0.00735	200

Sprays with                   Ground-boom (4)---b	long pants short
sleeve	0.0639

(Day 1987)	0.455

(Day 1987)	Turf	0.26	80	0.00113	0.000134	0.001264	1,200

Granules with Tractor-Drawn Spreader (5)	Single layer no gloves	0.0099 

(PHED)	1.2

(PHED)	Turf	1.5	80	0.001018	0.002057	0.003075	500

Mixer/Loader/Applicator

Wettable Powder (WSP) with Handgun (6)	Single layer +gloves	1.2         
   (ORETF) 	43              (ORETF) 	Turf	1.5	5	0.007714	0.004607
0.01232	120

Liquid with                    Handgun (7)	Single layer +gloves	2.4     
       (ORETF) 	3.4             (ORETF) 	Turf	0.26	5	0.002674	0.0000631
0.002737	550

Granules with        Push-Type Spreader (8)	long pants short sleeve	0.67
(ORETF)	0.88 (ORETF)	Turf	1.5
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a	Baseline consists of long-sleeve shirt, long pants, shoes, and socks
and no respirator.  PPE consists of long-sleeve shirt, long pants,
shoes, socks, chemical-resistant gloves, and no respirator.

b	Baseline Dermal Unit Exposure represents long pants, long sleeved
shirt, no gloves, open mixing/loading, and open cab tractors, as
appropriate.  

c	Baseline Inhalation Exposure represents no respiratory protection,
open mixing/loading, and open cab tractors, as appropriate.  

d	Daily acres treated values are from EPA estimates of acreage that
could be treated or volume handled in a single day for each exposure
scenario of concern, based on the application method and
formulation/packaging type.

e	Daily dermal dose (mg/kg/d) =  [unit dermal exposure (mg/lb ai) *
dermal absorption (0.06) * application rate (lb ai/acre) * daily acres
treated /  body weight (70 kg).

f	Daily inhalation dose (mg/kg/d) = (unit exposure (µg/lb ai) *
(1mg/1000 µg) conversion * application rate (lb ai/acre) * daily acres
treated / body weight (70 kg).

g	Combined daily dose = daily dermal dose + daily inhalation dose.

h	MOE = NOAEL (1.5 mg/kg/d) / combined daily dose.  UF = 100.

Table 11.  Anticipated Post-application Activities and Dermal Transfer
Coefficients

Proposed Crops	

Policy Crop Group Category	

Exposure Potential	

Transfer Coefficients (cm2/hour)	

Activities

Turf/Sod 	Golf course/Sod	Mowing	500	irrigation, weeding

Turf/Sod 	Golf course/Sod	Maintenance	3400	course maintenance

 Table 12.  Short-Term Post-application Exposure and Risk for
Occupational Handlers

Crop	

Application Rate 

(lb ai/A)	

Work Activity	

Transfer Coefficientsa (cm2/hr)	

TTR Fractionb	

TTRc

(mg/cm2)	

Daily Dosed (mg/kg/day)	

 MOE e 

Turf/Sod 	1.5	irrigation, weeding	500	5%	0.000841	0.00336	3,000

Turf/Sod 	1.5	course maintenance	3400	5%	0.000841	0.0229	440

a	Transfer coefficient from Science Advisory Council for Exposure:
Policy Memo #003 "Agricultural Transfer Coefficients," 05/07/98.

b	Fraction of ai retained on foliage (unitless)

c	TTR = Application Rate (lb ai/acre) x Fraction of active ingredient
that remains on the foliage when sprays have dried  x 4.54E8 µg/lb x
24.7E-9 acre/cm2.

d	Daily dose = TTR (mg/cm2) x TC (cm2/hr) x exposure time (8 hrs/day) x
dermal absorption (0.06) / body weight (60 kg).

e	MOE = NOAEL (10 mg/kg/day) / daily dose (mg/kg/day).

Table 13.  Intermediate-Term Post-application Exposure and Risk for
Occupational Handlers

Crop	

Application Rate 

(lb ai/A)	

Work Activity	

Transfer Coefficientsa (cm2/hr)	

TTR Fractionb	

TTRc

(mg/cm2)	

Daily Dosed (mg/kg/day)	

 MOE e 

Turf/Sod 	1.5	irrigation, weeding	500	5%	0.000841	0.00336	450

Turf/Sod 	1.5	course maintenance	3400	5%	0.000841	0.0229	66

a	Transfer coefficient from Science Advisory Council for Exposure:
Policy Memo #003 "Agricultural Transfer Coefficients," 05/07/98.

b	Fraction of ai retained on foliage (unitless)

c	TTR = Application Rate (lb ai/acre) x Fraction of active ingredient
that remains on the foliage when sprays have dried  x 4.54E8 µg/lb x
24.7E-9 acre/cm2.

d	Daily dose = TTR (mg/cm2) x TC (cm2/hr) x exposure time (8 hrs/day) x
dermal absorption (0.06) / body weight (70 kg).

e	MOE = NOAEL (1.5 mg/kg/day) / daily dose (mg/kg/day).

6.0         SEQ CHAPTER \h \r 1 REVIEW OF HUMAN RESEARCH

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 studies, which comprise the Pesticide Handlers
Exposure Database (PHED) and information from the Agricultural Re-Entry
Task Force (ARTF) & Outdoor Residential Exposure Task Force (ORETF),
have been determined to require a review of their ethical conduct, and
have received that review. The studies in PHED, ORETF and ARTF were
considered appropriate (or ethically conducted) for use in risk
assessments.

CC:   RAB2 RF, C. Swartz, S. Wang

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