UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C.  20460

OFFICE OF PREVENTION

 PESTICIDES AND

TOXIC SUBSTANCES

									01 March 2007

MEMORANDUM

SUBJECT:	Chlorflurenol: Human Health Risk Assessment Addendum for the
Reregistration Eligibility Decision Document.

FROM:	Shanna Recore 

		P. Yvonne Barnes

		Reregistration Branch 2

		Health Effects Division (7509P)

TO:		Tracy Perry

			Reregistration Branch 3

		Special Review and Reregistration Division (7508P)

THROUGH:	Alan Nielsen, Senior Scientist

		William Hazel, Chief

		Reregistration Branch 2

		Health Effects Division (7509P)

DP Barcode:		D337213

Pesticide Chemical Codes:  	098801

	This document serves as an addendum to HED’s 07/10/2006 human health
risk assessment (D323832). It reflects dietary (drinking water),
residential and occupational exposures and risks revised to reflect
reduced application rates for chlorflurenol committed to by the
registrant after the 07/10/2006 assessment. A portion of the attached
summary is excerpted from Chlorflurenol: Revised Occupational and
Residential Exposure Assessment for the Reregistration Eligibility
Decision Document (Recore 02/27/2007). 1.0	 REVISED OCCUPATIONAL AND
RESIDENTIAL EXPOSURE/RISK 	ASSESSMENT SUMMARY

	Chlorflurenol Methyl Ester (chlorflurenol) is an herbicide, plant
growth retardant, and plant growth regulator that is used in
agricultural, commercial, and residential settings.  As an herbicide
and/or plant growth retardant, chlorflurenol is used for the
postemergent control of annual grasses, broadleaf weeds, trees, shrubs,
and vines. As a plant growth regulator, chlorflurenol is in the
production of pineapple planting material (sliplets). Chlorflurenol is
registered as emulsifiable concentrate and granular formulations. The
emulsifiable concentrate formulations are applied using groundboom
sprayer, rights-of-way sprayer, handgun sprayer, low pressure handwand
sprayer, and airblast sprayer. Granular formulations are applied using a
bellygrinder, push-type spreader, and tractor-drawn spreader.  Table 1a,
1b, and 1c show the current application rates used in the revised
occupational and residential assessment.

  SEQ CHAPTER \h \r 1 Table 1a: Summary of Maximum Application Rates
for Registered Chlorflurenol Agricultural Uses

Crop Site	Target of Application	Maximum Application Rate	Application
Equipment	Area Treated or Amount Handled Per Day

Liquid Formulations

Pineapple plants:

for plant material production (non food use)	Plant growth regulator	1 lb
ai/A	groundboom	80 acres



	airblast	40 acres



  SEQ CHAPTER \h \r 1 Table 1b: Summary of Maximum Application Rates for
Registered Chlorflurenol Commercial Uses

Crop Site	Target of Application	Maximum Application Rate	Application
Equipment	Area Treated or Amount Handled Per Day

Liquid Formulations

Turf:  ornamental and lawns, golf courses, parks	Broadleaf weeds and
plant growth retardant	0.5 lb ai/A	handgun	Lawns and Ornamental:

5 acres for A and M/L/A

100 acres for M/L (for 20 LCOs)



	low pressure handwand	5 acres



	groundboom	40 acres

Weed Turf:

growing in culverts, ROW, median strips, ditches, under security fences

Weed Hardwoods: growing under utility lines, as screens or ground cover,
adjacent to highways 

Weed Hedges/Vines: growing under utility lines as screens or ground
cover, ROW, hedgerows	Plant growth regulator	1.0 lb ai/acre
rights-of-way sprayer 	80 acres



	handgun	5 acres



	low-pressure handwand	5 acres

Weed Gymnosperms	Plant growth retardant	0.25 lb ai/A	rights-of-way
sprayer 	80 acres 



	handgun	5 acres



	low pressure handwand 	5 acres 

Trees:

bark banding	Plant growth retardant	0.083 lb ai/gal	low-pressure
handwand	40 gallons

Ornamental/Shade Trees (e.g., olives, oranges)	Plant growth regulator
1.0 lb ai/acre	handgun	5 acres



	low-pressure handwand	5 acres

High Density Forestry Management	Plant growth regulator	2.0 lb ai/acre
low-pressure handwand	5 acres

Granular Formulations

Turf:  Lawns and Ornamental Turf  (including golf course and parks)
Broadleaf weeds	0.5 lb ai/acre	tractor-drawn spreader	40 acres



	push-type spreader	5 acres



	belly grinder	1 acre



  SEQ CHAPTER \h \r 1 Table 1c: Summary of Maximum Application Rates
for Registered Chlorflurenol Residential Uses

Crop Site	Target of Application	Maximum Application Rate	Application
Equipment	Area Treated or Amount Handled Per Day

Granular Formulations

Turf:  lawns	Broadleaf weeds	0.25 lb ai/A	push-type spreader	0.5 acre



	belly grinder	1,000 ft2



Hazard Concerns

  SEQ CHAPTER \h \r 1 Adverse effects were identified at durations of
exposure ranging from short-term (up to 30 days) to long-term (> 6
months).  The short- and intermediate-term dermal, inhalation, and
incidental oral endpoints are based on a NOAEL of 31 mg/kg/day from a
chronic 2-year feeding study in dogs where the LOAEL is 90 mg/kg/day. 
The LOAEL is based on decreased erythrocyte, hemoglobin and hematocrit
at 4 weeks. Long-term exposures to chlorflurenol (i.e., greater than 6
months) are not expected for current registered uses.  Additionally, no
cancer endpoint was identified; therefore cancer risks are not assessed.

	HED’s level of concern (LOC) for chlorflurenol occupational and
residential dermal and inhalation exposures is 100 (i.e., a margin of
exposure (MOE) less than 100 exceeds HED’s level of concern).  The
dermal and inhalation margins of exposure were combined for the
occupational and residential handler risk assessments because the
toxicity endpoints for the dermal and inhalation routes of exposure are
based on the same toxicological effects.  For incidental oral exposures,
HED’s level of concern is 300 (i.e., a margin of exposure (MOE) less
than 300 exceeds HED’s level of concern). The dermal and incidental
oral ingestion margins of exposure for the residential postapplication
risk assessments for toddlers were also aggregated because the toxicity
endpoints for the dermal and oral routes of exposure are based on the
same toxicological effects.  

Occupational Handler Risks

	HED has determined that there are potential exposures to mixers,
loaders, applicators, and other handlers during the usual use-patterns
associated with chlorflurenol. These risks were calculated assuming
maximum application rates from the product labels or using the proposed
maximum application rates reported by the Registrant. 

	For all occupational scenarios, the inhalation risks were below HED’s
level of concern at the baseline level.  

	For the scenarios listed below, the dermal and total risks were of
concern at baseline level of mitigation, but were not a concern with
single layer attire plus gloves.

mixing/loading liquid concentrates for all scenarios, except
mixing/loading liquid concentrates to support handgun applications to
ornamental/shade trees and to  weeds (turf, hardwoods, hedges, and
vines, and gymnosperms);

applying liquid concentrates with rights-of-way equipment for weed
gymnosperms; and 

mixing/loading/applying liquid concentrates with low pressure handwand
(PHED data and ORETF ground-directed data) for all scenarios.

For the one scenario listed below, the dermal and total risks remained
at concern with the highest level of mitigation (double layer clothing
plus gloves), though risks were only slightly below HED’s level of
concern of 100.

applying liquid concentrates with rights of way equipment for weed turf,
hardwoods, hedges, and vines (dermal MOE = 94 and total MOE = 92). 

For four scenarios listed below, the dermal and total risks remained at
concern with the only data available – baseline attire.  However,
since both the PHED data and the ORETF ground-directed data for
low-pressure handwand equipment have similar risks at baseline, but
dermal risks are not of concern with the addition of chemical-resistant
gloves, it could be assumed that these scenarios would not be of concern
with the addition of chemical-resistant gloves.

Mixing/loading/applying liquid concentrates with low-pressure handwand
equipment using ORETF data for upward-directed sprays on weed hardwoods,
hedges, and vines (dermal MOE = 14 and total MOE = 14). 

Mixing/loading/applying liquid concentrates with low-pressure handwand
equipment using ORETF data for upward-directed sprays on ornamental and
shade trees (dermal MOE = 14 and total MOE = 14). 

Mixing/loading/applying liquid concentrates with low-pressure handwand
equipment using ORETF data for upward-directed sprays on weed
gymnosperms (dermal MOE = 58 and total MOE = 58). 

Mixing/loading/applying liquid concentrates with low-pressure handwand
equipment using ORETF data for upward-directed sprays for high density
forest management (dermal MOE = 7.2 and total MOE = 7.2). 

	There are no data to assess baseline dermal risks for application via
handgun equipment and mixing/loading/applying via handgun equipment.
Dermal risks are below HED’s level of concern for handlers of these
scenarios with a single layer attire plus gloves. 

Occupational Postapplication Risks

	HED has determined that there are potential exposures to
postapplication occupational workers during the usual use-patterns
associated with chlorflurenol.  Specifically, HED is concerned about
postapplication exposures from treatment of pineapples and golf course
turf. To develop a postapplication assessment, HED considers the types
of tasks and activities that individuals are likely to be doing in areas
recently treated with a pesticide. In agricultural crop settings, the
use of personal protective equipment or other types of equipment to
mitigate postapplication exposures to workers is not considered a viable
alternative for the regulatory process. Instead, an administrative
approach – a Restricted Entry Interval or REI – is used to mitigate
postapplication risks following applications to crops.  The REI is time
period following a pesticide application during which entry into the
treated area is restricted.  Postapplication risk levels are generally
calculated in the risk assessment process on a chemical-, crop-, and
activity-specific basis.  To establish REIs, HED considers
postapplication risks on varying days after application. For pineapple
and golf course turf applications, the MOEs are greater than 100 on day
0 (REI = 12 hours) for all of the activity levels.	

Residential Handler Risks

	HED has determined that there are potential exposures to residential
handlers during the usual use-patterns associated with chlorflurenol.
All non-cancer risks (i.e., MOEs) to handlers associated with the
scenarios are not of concern, because they exceed HED’s uncertainty
factor of 100.

Residential Postapplication Risks

	The following residential postapplication scenarios were identified: 

	

dermal exposure from residue on lawns and turf (adult, youth and
toddler), 

hand-to-mouth transfer of residues on lawns (toddler), 

ingestion of pesticide residue on treated grass (toddler), and 

incidental ingestion of soil from pesticide-treated residential areas
(toddler).

For the adult, youth and toddler populations, all postapplication
non-cancer risks were below HED’s level of concern. Calculated
combined risks to toddlers (i.e., dermal high contact activity plus hand
to mouth activity plus object to mouth activity on treated turf plus
incidental soil ingestion of pesticide residue from treated turf areas)
were also below HED’s level of concern.

2.0 	 REVISED DIETARY EXPOSURE/RISK ASSESSMENT SUMMARY

		

	 Dietary Exposure/Risk Characterization    TC \l1 "5.0	Dietary
Exposure/Risk Characterization 

	Chlorflurenol methyl ester is a nonfood use pesticide having no
tolerances to reassess.  Consequently, there are no residue chemistry
data requirements and thus, dietary exposure and risk assessments are
not applicable.  Chlorflurenol methyl ester is used on pineapple after
fruit harvest to stimulate production of vegetative planting material
(slips).  The time between pesticide treatment and the first harvest of
pineapple fruit would be 1.5 to 2 years.  No residues are expected in
the fruit according to a HED Greybeard Committee decision in 1995 [TXR#
012504].  HED upholds this decision in this addendum.

	Drinking Water Residue Profile TC \l3 "5.1.9	Drinking Water Residue
Profile 

	It should be noted that drinking water exposure to chlorflurenol methyl
ester is very limited.  Due to the limited number of pounds per year
used, this water contamination is likely limited to use areas only.  It
follows that expanded use, would result in additional contamination.

	Chronic drinking water exposure were modeled by Dietary Exposure
Evaluation Model (DEEM-FCID(, Version 2.03), which uses food consumption
data from the USDA’s Continuing Surveys of Food Intakes by Individuals
(CSFII) from 1994-1996 and 1998 using surface water concentration, which
showed all groups were exposed to levels below the chronic oral endpoint
of 0.1 mg/kg/day.  Non-nursing infants and all infants (< 1 year) were
exposed to the highest percentage of the RfD at 0.4% and 0.3%
respectively.  All other groups were exposed to residues in drinking
water at 0.1% to 0.2% of the oral chronic RfD of 0.1 mg/kg/day.  These
levels are below EPA’s level of concern see (Table 2A).  

Table 2A.  Chlorflurenol:  Selected population exposures (selected for 
surface water exposures within a group)

Population subgroup	mg/kg/day 	Percent of the endpoint of

0.10 mg/kg/day

US population (summer season)	0.000113	0.1

Western region	0.000121	0.1

Hispanics	0.000120	0.1

Non-hispanic blacks	0.000100	0.1

Non-hispanic/non-white/non-black	0.000129	0.1

All infants (<1 year)	0.000346	0.3

Nursing infants	0.000128	0.1

Non-nursing infants 	0.000428	0.4

Females 20+ (not pregnant or nursing)	0.000105	0.1

Females 13-50 years	0.000102	0.1

Females 13+ nursing	0.000146	0.1

Males 20+ yrs	0.000094	0.1

Seniors 55+	0.000103	0.1

Children 1-2 years	0.000156	0.2

Children 3-5 years	0.000147	0.1

Children 6-12 years	0.000101	0.1

Youths 13-19 yrs	0.000076	0.1

For drinking water, the Deem software was modeled using surface water
concentration at 5.0 ppb.



	Chronic drinking water exposures were also modeled by the DEEM software
using the estimated ground water concentration.  Non-nursing infants and
all infants (< 1 year) were exposed to the highest percentage of the RfD
at 3.7% and 3.0% respectively.  All other groups were exposed to
drinking water at 0.7% to 1.3% of the oral chronic RfD of 0.1 mg/kg/day.
 These levels are below EPA’s level of concern see (Table 2B).  

Table 2B.  Chlorflurenol:  Selected population exposures (selected for 
ground water exposures within a group)

Population subgroup	mg/kg/day	Percent of the endpoint of

0.10 mg/kg/day

US population (summer season)	0.000967	1.0

Western region	0.001031	1.0

Hispanics	0.001022	1.0

Non-hispanic blacks	0.000854	0.9

Non-hispanic/non-white/non-black	0.001103	1.1

All infants (<1 year)	0.002951	3.0

Nursing infants	0.001094	1.1

Non-nursing infants 	0.003655	3.7

Females 20+ (not pregnant or nursing)	0.000898	0.9

Females 13-50 years	0.000871	0.9

Females 13+ nursing	0.001247	1.2

Males 20+ yrs	0.000806	0.8

Seniors 55+	0.000884	0.9

Children 1-2 years	0.001337	1.3

Children 3-5 years	0.001251	1.3

Children 6-12 years	0.000863	0.9

Youths 13-19 yrs	0.000651	0.7

For drinking water, the Deem software was modeled using ground water
concentration at 42.7 ppb.



	Potential drinking water residues were estimated for groundwater from
Tier I SCIGROW and surface water from Tier II PRZM and EXAMS models. 
The OPP/EFED Florida turf scenario was selected for this assessment. 
For this assessment, it was assumed that 1 application of chlorflurenol
methyl ester was applied to turf grass at a rate of 0.5 pounds active
ingredient per acre and the pesticide is stable in the environment. 
This would represent a maximum concentration in a shallow, private well
in a high usage area.  Surface water concentrations are 9.4 ppb for
acute concentration; 5.0 ppb for chronic non-cancer: and 42.7 ppb for
ground water concentration (see Table 3).

Table 3. 	Summary of Estimated Surface Water and Groundwater
Concentrations for Chlorflurenol

Application

Rate (lbs/ac)	Number of Applications per Year	Acute Surface             
(ppb)	Chronic non-cancer (ppb)	Chronic cancer (ppb)	Groundwater

(ppb)

0.5	1	9.4	5.0	2.5	42.7



	PHYSICAL CHEMICAL PROPERTIES

	The product chemistry data gap in Table 4/page 12 of the document
Chlorflurenol Methyl Ester.  HED Chapter of the Reregistration
Eligibility Decision Document (RED), dated 10 July 2006 is outlined in
OPPTS Guideline Series 830-7050 UV/Visible Absorption. The rationale for
the requirement is stated below.

UV/Visible Absorption Data Gap

Product Properties Test Guidelines require data pertaining to UV/Visible
absorption for the pure active ingredient.  Determination of the
UV/Visible absorption spectrum of a pesticide provides some indication
of the wavelengths at which the compound may be susceptible to
photochemical degradation.  This study is required of all pesticide
chemicals as additional characterization of the active ingredient's
properties.

Attachments:

Attachment 1. Chronic Results (Surface Water)

Attachment 2. Chronic Results (Ground Water)

Attachment 1.  Chronic Results (Surface Water)

U.S. Environmental Protection Agency                                Ver.
2.00

DEEM-FCID Chronic analysis for CHLORFLURENOL                    (1994-98
data)

Residue file name: C:\Documents and
Settings\pbarnes\Desktop\chlorflurenol 6 13 2006\new water only
runs\chlorflurenol 03 01 2007.R98

                                                Adjustment factor #2 NOT
used.

Analysis Date 03-01-2007/09:42:27     Residue file dated:
03-01-2007/09:41:47/8

Reference dose (RfD, Chronic) = .1 mg/kg bw/day

COMMENT 1: Application Rate 0.5 lbs/acre

========================================================================
=====

                    Total exposure by population subgroup

------------------------------------------------------------------------
-----

                                                    Total Exposure

                                        
-----------------------------------

          Population                         mg/kg             Percent
of   

           Subgroup                       body wt/day             Rfd   
   

--------------------------------------   -------------      
---------------

U.S. Population (total)                     0.000105                
0.1%

U.S. Population (spring season)             0.000104                
0.1%

U.S. Population (summer season)             0.000113                
0.1%

U.S. Population (autumn season)             0.000102                
0.1%

U.S. Population (winter season)             0.000102                
0.1%

Northeast region                            0.000096                
0.1%

Midwest region                              0.000107                
0.1%

Southern region                             0.000100                
0.1%

Western region                              0.000121                
0.1%

Hispanics                                   0.000120                
0.1%

Non-hispanic whites                         0.000103                
0.1%

Non-hispanic blacks                         0.000100                
0.1%

Non-hisp/non-white/non-black                0.000129                
0.1%

All infants (< 1 year)                      0.000346                
0.3%

Nursing infants                             0.000128                
0.1%

Non-nursing infants                         0.000428                
0.4%

Children 1-6  yrs                           0.000147                
0.1%

Children 7-12 yrs                           0.000096                
0.1%

Females 13-19 (not preg or nursing)         0.000074                
0.1%

Females 20+ (not preg or nursing)           0.000105                
0.1%

Females 13-50 yrs                           0.000102                
0.1%

Females 13+ (preg/not nursing)              0.000102                
0.1%

Females 13+ (nursing)                       0.000146                
0.1%

Males 13-19 yrs                             0.000078                
0.1%

Males 20+ yrs                               0.000094                
0.1%

Seniors 55+                                 0.000103                
0.1%

Children 1-2 yrs                            0.000156                
0.2%

Children 3-5 yrs                            0.000147                
0.1%

Children 6-12 yrs                           0.000101                
0.1%

Youth 13-19 yrs                             0.000076                
0.1%

Adults 20-49 yrs                            0.000098                
0.1%

Adults 50+ yrs                              0.000104                
0.1%

Females 13-49 yrs                           0.000098                
0.1%

------------------------------------------------------------------------
-------

Attachment 2.  Chronic Results (Ground Water)

U.S. Environmental Protection Agency                                Ver.
2.00

DEEM-FCID Chronic analysis for CHLORFLURENOL                    (1994-98
data)

Residue file name: C:\Documents and
Settings\pbarnes\Desktop\chlorflurenol 6 13 2006\new water only
runs\chlorflurenol  03 01 2007 ground water only.R98

                                                Adjustment factor #2 NOT
used.

Analysis Date 03-01-2007/09:46:24     Residue file dated:
03-01-2007/09:45:50/8

Reference dose (RfD, Chronic) = .1 mg/kg bw/day

COMMENT 1: ground water

========================================================================
=====

                    Total exposure by population subgroup

------------------------------------------------------------------------
-----

                                                    Total Exposure

                                        
-----------------------------------

          Population                         mg/kg             Percent
of   

           Subgroup                       body wt/day             Rfd   
   

--------------------------------------   -------------      
---------------

U.S. Population (total)                     0.000900                
0.9%

U.S. Population (spring season)             0.000892                
0.9%

U.S. Population (summer season)             0.000967                
1.0%

U.S. Population (autumn season)             0.000870                
0.9%

U.S. Population (winter season)             0.000870                
0.9%

Northeast region                            0.000821                
0.8%

Midwest region                              0.000910                
0.9%

Southern region                             0.000855                
0.9%

Western region                              0.001031                
1.0%

Hispanics                                   0.001022                
1.0%

Non-hispanic whites                         0.000878                
0.9%

Non-hispanic blacks                         0.000854                
0.9%

Non-hisp/non-white/non-black                0.001103                
1.1%

All infants (< 1 year)                      0.002951                
3.0%

Nursing infants                             0.001094                
1.1%

Non-nursing infants                         0.003655                
3.7%

Children 1-6  yrs                           0.001257                
1.3%

Children 7-12 yrs                           0.000818                
0.8%

Females 13-19 (not preg or nursing)         0.000633                
0.6%

Females 20+ (not preg or nursing)           0.000898                
0.9%

Females 13-50 yrs                           0.000871                
0.9%

Females 13+ (preg/not nursing)              0.000875                
0.9%

Females 13+ (nursing)                       0.001247                
1.2%

Males 13-19 yrs                             0.000662                
0.7%

Males 20+ yrs                               0.000806                
0.8%

Seniors 55+                                 0.000884                
0.9%

Children 1-2 yrs                            0.001337                
1.3%

Children 3-5 yrs                            0.001251                
1.3%

Children 6-12 yrs                           0.000863                
0.9%

Youth 13-19 yrs                             0.000651                
0.7%

Adults 20-49 yrs                            0.000840                
0.8%

Adults 50+ yrs                              0.000884                
0.9%

Females 13-49 yrs                           0.000837                
0.8%

------------------------------------------------------------------------
-------

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