Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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II. Residue Information

Registered and Proposed Fluroxypyr Tolerances

Tolerances have been established for the combined residues of fluroxypyr 1-methylheptyl 

ester [1-methylheptyl ((4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy)acetate] and its 

metabolite fluroxypyr [((4-amino-3,5-dichloro-6-fluoro-2-pyridinyl)oxy)acetic acid] 

under 40 CFR 180.535. The established tolerances for plant commodities range from 0.02 

ppm (field corn grain, sweet corn K+CWHR, and sorghum grain) to 160 ppm (grass hay) 

[40 CFR 180.535(a)]. The established tolerances for livestock commodities range from 

0.1 ppm (fat, meat, and meat byproducts) to 1.5 ppm (kidney). 

New use for fluroxypyr is proposed for rice. The proposed label recommends application 

of fluroxypyr to the rice field up to 60-days before harvest. HED has recommended that 

a tolerance of 1.5 ppm be established for rice.

Residue Data used for Chronic Assessment:

The chronic dietary (food and drinking water) analysis assumed 100% crop treated, 

DEEM 7.81 default processing factors and tolerance-level residues for all commodities. 

The recommended tolerances for rice (1.5 ppm) and rice bran (3.0 ppm) were 

incorporated into the assessment for the new use. 

III. Drinking Water Data

The drinking water residues used in the dietary risk assessment were provided by the

Environmental Fate and Effects Division (EFED). Estimated Environmental

Concentrations (EEC) values were provided to HED in the memorandum entitled

Drinking Water Assessment for New Use of Fluroxypyr in Rice (Paddies) (DP 396343,

Ronald Parker, 08/21/12). Water residues were incorporated in the DEEM FCIDTM into

the food categories “water, direct, all sources” and “water, indirect, all sources.” 

The fluroxypyr estimated drinking water concentration (EDWC) value is 540 μg/L (ppb) 

for both acute and chronic exposure. Details of the EFED Tier 1 Rice Model can be 

found at http://www.epa.gov/oppefed1/models/water/rice_tier_i.htm. 

A screening assessment for the impact of fluroxypyr on potential groundwater drinking 

water sources, using the Tier 1 groundwater model SCI-GROW(Screening Concentration 

In GROund Water), was also conducted. EDWC values based on use of the EFED SCIGROW model is 0.055 μg/L (ppb) for both acute and chronic exposures. SCI-GROW 

model details can be found at: http://www.epa.gov/oppefed1/models/water/#scigrow. 

Estimation of Exposure Concentrations for Surface Water in Rices Paddies (Tier 1 Rice 

Model)

The proposed new use label for application to rice permits a single maximum application 

rate of 0.34 lb ai/acre/year and allows for two applications with a maximum total of 0.568 

lb ai/acre/year with a minimum retreatment interval (RTI) of ten days. The label also 
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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requires a pre-harvest interval (PHI) of 60 days. This assessment reflects a high-exposure 

scenario by assuming the maximum application rate of 0.568 lb ai/A (0.64 kg/ha) is used 

per year.

Tier 1 Rice Model (v1): when using the Tier 1 rice model, EFED assumes pesticide 

application to a static rice paddy with no inflow from rainfall or outflow from seepage, 

overflow or evaporation. The only process simulated by the model is partitioning of the 

applied chemical between the 10-centimeter deep water column and the 1-centimeter 

deep sediment layer of the paddy. The partitioning is based on the pesticide’s deredation 

coefficient Kd. Degradation in the paddy is not calculated by the model so the pesticide is 

assumed to remain at the initial concentration in the water indefinitely. Results of the tier 

1 rice modeling are presented in Table 1. Acute and chronic values are equal because the 

model does not simulate degradation of the pesticide in the paddy.

Table1. Summary of Tier 1 Rice Model EDWC for Use on Rice

Assessment Type Acute EDWC Chronic EDWC

Tier 1 Rice Model (conc in paddy) 540 μg/L (ppb) 540 μg/L (ppb)

IV. DEEM-FCIDTM Program and Consumption Information

Fluroxypyr chronic dietary exposure assessments was conducted using the Dietary 

Exposure Evaluation Model software with the Food Commodity Intake Database DEEMFCIDTM, Version 3.16 which incorporates consumption data from USDA’s National 

Health and Nutrition Examination Survey)/“What We Eat in America” 

(NHANES/WWEIA) dietary survey conducted in 2003-2008. The 2003-2008 data are 

based on the reported consumption of more than 20,000 individuals over two nonconsecutive survey days. Foods “as consumed” (e.g., apple pie) are linked to EPAdefined food commodities (e.g. apples, peeled fruit - cooked; fresh or N/S; baked; or 

wheat flour - cooked; fresh or N/S, baked) using publicly available recipe translation files 

developed jointly by USDA/ARS and EPA. For chronic exposure assessment, 

consumption data are averaged for the entire U.S. population and within population 

subgroups, but for acute exposure assessment are retained as individual consumption 

events. Based on analysis of the 2003-2008 WWEIA consumption data, which took into 

account dietary patterns and survey respondents, HED concluded that it is most 

appropriate to report risk for the following population subgroups: the general U.S. 

population, all infants (<1 year old), children 1-2, children 3-5, children 6-12, youth 13-

19, adults 20-49, females 13-49, and adults 50+ years old.

For chronic dietary exposure assessment, an estimate of the residue level in each food or 

food-form (e.g., orange or orange juice) on the food commodity residue list is multiplied 

by the average daily consumption estimate for that food/food form to produce a residue 

intake estimate. The resulting residue intake estimate for each food/food form is summed 

with the residue intake estimates for all other food/food forms on the commodity residue 

list to arrive at the total average estimated exposure. Exposure is expressed in mg/kg 

body weight/day and as a percent of the cPAD. This procedure is performed for each 

population subgroup.
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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V. Toxicological Information

The toxicology database is considered complete for the purposes of this risk assessment. 

The Fluroxypyr Risk Assessment Team has reviewed the toxicity database and has 

concluded that the doses and endpoints previously selected for risk assessment purposes 

remain consistent with current HED policy and are appropriate for the routes and 

durations of exposure anticipated from the existing and newly proposed uses of 

fluroxypyr. 

Endpoints for risk assessment were based on kidney effects seen in the database. Doses 

selected for dietary risk assessment purposes are summarized below. The FQPA safety 

factor was reduced to 1X since the toxicity database was considered complete, there were 

no residual uncertainties for pre-and/or post natal toxicity, no evidence of neurotoxicity 

or neuropathology was found, and the estimated exposures were not likely to 

underestimate risk.

Table 2. Summary of Toxicological Doses and Endpoints for Fluroxypyr for Use in Human Risk Assessments

Exposure

Scenario

Dose Used 

in Risk 

Assessmen

t, UF 

FQPA SF* and Level 

of Concern for Risk 

Assessment

Study and Toxicological Effects

Acute Dietary

(All populations)

No adverse effects were identified following a single oral dose and there are no 

developmental concerns noted in the database. A risk assessment for this route 

and duration is not required.

Chronic Dietary

(All populations)

NOAEL= 

100 

mg/kg/day

UF = 100

chronic 

RfD = 

1 

mg/kg/day

FQPA SF = 1x

chronic PAD = 

1 mg/kg/day

Chronic/Onco-Rat

LOAEL = 500 mg/kg/day based on 

kidney effects, which include 

increased kidney weights, alterations 

in clinical chemistry parameters 

indicative of impaired renal functions, 

and increase in severity of chronic 

progressive glomerulonephropathy 

(both sexes).

Cancer (oral, dermal, inhalation) Classification: “not likely” human carcinogen

UF = uncertainty factor, FQPA SF = FQPA safety factor, NOAEL = no observed adverse effect level, 

LOAEL = lowest observed adverse effect level, PAD = population adjusted dose, RfD = reference dose, 

NA = Not Applicable

VI. Results/Discussion 

As stated above, for chronic assessments, HED is concerned when dietary risk exceeds 

100% of the cPAD. The DEEM-FCIDTM analyses estimate the dietary exposure of the 

U.S. population and various population subgroups. The results of the chronic dietary 

assessment reported in Table 3 are for the general U.S. Population, all infants (<1 year 
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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old), children 1-2, children 3-5, children 6-12, youth 13-19, females 13-49, adults 20-49, 

and adults 50+ years. 
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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Results of Chronic Dietary Exposure Analysis

The results of the chronic dietary exposure analysis are reported in the summary table 

below. 

Table 3. Summary of Chronic Dietary (Food and Drinking Water) Exposure and Risk for Fluroxypyr

Population Subgroup

Chronic Dietary

Dietary Exposure (mg/kg/day) % cPAD

General U.S. Population 0.014731 1.5

All Infants (< 1 year old) 0.035101 3.5

Children 1-2 years old 0.032830 3.3

Children 3-5 years old 0.024049 2.4

Children 6-12 years old 0.015918 1.6

Youth 13-19 years old 0.011206 1.1

Adults 20-49 years old 0.013645 1.4

Adults 50+ years old 0.013107 1.3

Females 13-49 years old 0.013459 1.3

VII. Characterization of Inputs/Outputs

The Tier 1 chronic dietary assessment is considered to be highly conservative, using 

tolerance level residues and 100% crop treated information for all commodities, as well 

as default drying concentration factors. The results of the dietary risk assessment are 

unlikely to underestimate risk.

 

VIII. Conclusions

An unrefined, Tier 1 chronic dietary exposure assessment using tolerance level residues 

and 100% crop treated incorporating modeled water residues was conducted to support 

new use on rice. The assessment is considered highly conservative. Exposures from 

fluroxypyr for the U.S. population resulted in an estimated risk equivalent to 1.5% of the 

cPAD. The most highly exposed population subgroup is infants (<1 year old) with an 

exposure equivalent to an estimated risk of 3.5% of the cPAD. 
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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IX. List of Attachments

• Chronic Food and Water Residue Input file.

• Chronic Results file.
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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Attachment 1. Chronic Food and Water Residue Input file.

Company Name Ver. 3.16, 03-08-d

DEEM-FCID Chronic analysis for FLUROXYPYR

Residue file: C:\Documents and Settings\stadayon\My Documents\Work in 

Progress\Fluroxypyr\FLUR_CHRON_FW.R08

 Adjust. #2 used

Analysis Date 08-28-2012 Residue file dated: 08-28-2012/14:10:55

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

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

Food Crop Residue Adj.Factors

EPA Code Grp Food Name (ppm) #1 #2 

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

1100007000 11 Apple, fruit with peel 0.020000 1.000 1.000 

1100008000 11 Apple, peeled fruit 0.020000 1.000 1.000 

1100008001 11 Apple, peeled fruit-babyfood 0.020000 1.000 1.000 

1100009000 11 Apple, dried 0.020000 8.000 1.000 

1100009001 11 Apple, dried-babyfood 0.020000 8.000 1.000 

1100010000 11 Apple, juice 0.020000 1.300 1.000 

1100010001 11 Apple, juice-babyfood 0.020000 1.300 1.000 

1100011000 11 Apple, sauce 0.020000 1.000 1.000 

1100011001 11 Apple, sauce-babyfood 0.020000 1.000 1.000 

1500025000 15 Barley, pearled barley 0.500000 1.000 1.000 

1500025001 15 Barley, pearled barley-babyfood 0.500000 1.000 1.000 

1500026000 15 Barley, flour 0.500000 1.000 1.000 

1500026001 15 Barley, flour-babyfood 0.500000 1.000 1.000 

1500027000 15 Barley, bran 0.500000 1.000 1.000 

3100044000 31 Beef, meat 0.100000 1.000 1.000 

3100044001 31 Beef, meat-babyfood 0.100000 1.000 1.000 

3100045000 31 Beef, meat, dried 0.100000 1.920 1.000 

3100046000 31 Beef, meat byproducts 0.100000 1.000 1.000 

3100046001 31 Beef, meat byproducts-babyfood 0.100000 1.000 1.000 

3100047000 31 Beef, fat 0.100000 1.000 1.000 

3100047001 31 Beef, fat-babyfood 0.100000 1.000 1.000 

3100048000 31 Beef, kidney 1.500000 1.000 1.000 

3100049000 31 Beef, liver 0.100000 1.000 1.000 

3100049001 31 Beef, liver-babyfood 0.100000 1.000 1.000 

1500120000 15 Corn, field, flour 0.020000 1.000 1.000 

1500120001 15 Corn, field, flour-babyfood 0.020000 1.000 1.000 

1500121000 15 Corn, field, meal 0.020000 1.000 1.000 

1500121001 15 Corn, field, meal-babyfood 0.020000 1.000 1.000 

1500122000 15 Corn, field, bran 0.020000 1.000 1.000 

1500123000 15 Corn, field, starch 0.020000 1.000 1.000 

1500123001 15 Corn, field, starch-babyfood 0.020000 1.000 1.000 

1500124000 15 Corn, field, syrup 0.020000 1.500 1.000 

1500124001 15 Corn, field, syrup-babyfood 0.020000 1.500 1.000 

1500125000 15 Corn, field, oil 0.020000 1.000 1.000 

1500125001 15 Corn, field, oil-babyfood 0.020000 1.000 1.000 

1500126000 15 Corn, pop 0.020000 1.000 1.000 

1500127000 15 Corn, sweet 0.020000 1.000 1.000 

1500127001 15 Corn, sweet-babyfood 0.020000 1.000 1.000 

1100129000 11 Crabapple 0.020000 1.000 1.000 

0301165000 3A Garlic, bulb 0.030000 1.000 1.000 

0301165001 3A Garlic, bulb-babyfood 0.030000 1.000 1.000 

3200169000 32 Goat, meat 0.100000 1.000 1.000 

3200170000 32 Goat, meat byproducts 0.100000 1.000 1.000 

3200171000 32 Goat, fat 0.100000 1.000 1.000 

3200172000 32 Goat, kidney 1.500000 1.000 1.000 

3200173000 32 Goat, liver 0.100000 1.000 1.000 

3300189000 33 Horse, meat 0.100000 1.000 1.000 

1100210000 11 Loquat 0.020000 1.000 1.000 

3800221000 38 Meat, game 0.100000 1.000 1.000 

3600222000 36 Milk, fat 0.300000 1.000 1.000 

3600222001 36 Milk, fat-baby food/infant formu 0.300000 1.000 1.000 

3600223000 36 Milk, nonfat solids 0.300000 1.000 1.000 

3600223001 36 Milk, nonfat solids-baby food/in 0.300000 1.000 1.000 
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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3600224000 36 Milk, water 0.300000 1.000 1.000 

3600224001 36 Milk, water-babyfood/infant form 0.300000 1.000 1.000 

3600225001 36 Milk, sugar (lactose)-baby food/ 0.300000 1.000 1.000 

1500226000 15 Millet, grain 0.500000 1.000 1.000 

1500231000 15 Oat, bran 0.500000 1.000 1.000 

1500232000 15 Oat, flour 0.500000 1.000 1.000 

1500232001 15 Oat, flour-babyfood 0.500000 1.000 1.000 

1500233000 15 Oat, groats/rolled oats 0.500000 1.000 1.000 

1500233001 15 Oat, groats/rolled oats-babyfood 0.500000 1.000 1.000 

0301237000 3A Onion, bulb 0.030000 1.000 1.000 

0301237001 3A Onion, bulb-babyfood 0.030000 1.000 1.000 

0301238000 3A Onion, bulb, dried 0.030000 9.000 1.000 

0301238001 3A Onion, bulb, dried-babyfood 0.030000 9.000 1.000 

1100266000 11 Pear 0.020000 1.000 1.000 

1100266001 11 Pear-babyfood 0.020000 1.000 1.000 

1100267000 11 Pear, dried 0.020000 6.250 1.000 

1100268000 11 Pear, juice 0.020000 1.000 1.000 

1100268001 11 Pear, juice-babyfood 0.020000 1.000 1.000 

3400290000 34 Pork, meat 0.100000 1.000 1.000 

3400290001 34 Pork, meat-babyfood 0.100000 1.000 1.000 

3400291000 34 Pork, skin 0.100000 1.000 1.000 

3400292000 34 Pork, meat byproducts 0.100000 1.000 1.000 

3400292001 34 Pork, meat byproducts-babyfood 0.100000 1.000 1.000 

3400293000 34 Pork, fat 0.100000 1.000 1.000 

3400293001 34 Pork, fat-babyfood 0.100000 1.000 1.000 

3400294000 34 Pork, kidney 1.500000 1.000 1.000 

3400295000 34 Pork, liver 0.100000 1.000 1.000 

1100310000 11 Quince 0.020000 1.000 1.000 

3900312000 39 Rabbit, meat 0.100000 1.000 1.000 

1500323000 15 Rice, white 1.500000 1.000 1.000 

1500323001 15 Rice, white-babyfood 1.500000 1.000 1.000 

1500324000 15 Rice, brown 1.500000 1.000 1.000 

1500324001 15 Rice, brown-babyfood 1.500000 1.000 1.000 

1500325000 15 Rice, flour 1.500000 1.000 1.000 

1500325001 15 Rice, flour-babyfood 1.500000 1.000 1.000 

1500326000 15 Rice, bran 3.000000 1.000 1.000 

1500326001 15 Rice, bran-babyfood 3.000000 1.000 1.000 

0302338500 3B Shallot, fresh leaves 0.030000 1.000 1.000 

3500339000 35 Sheep, meat 0.100000 1.000 1.000 

3500339001 35 Sheep, meat-babyfood 0.100000 1.000 1.000 

3500340000 35 Sheep, meat byproducts 0.100000 1.000 1.000 

3500341000 35 Sheep, fat 0.100000 1.000 1.000 

3500341001 35 Sheep, fat-babyfood 0.100000 1.000 1.000 

3500342000 35 Sheep, kidney 1.500000 1.000 1.000 

3500343000 35 Sheep, liver 0.100000 1.000 1.000 

1500344000 15 Sorghum, grain 0.020000 1.000 1.000 

1500345000 15 Sorghum, syrup 0.020000 1.000 1.000 

8601000000 86A Water, direct, all sources 0.540000 1.000 1.000 

8602000000 86B Water, indirect, all sources 0.540000 1.000 1.000 

1500401000 15 Wheat, grain 0.500000 1.000 1.000 

1500401001 15 Wheat, grain-babyfood 0.500000 1.000 1.000 

1500402000 15 Wheat, flour 0.500000 1.000 1.000 

1500402001 15 Wheat, flour-babyfood 0.500000 1.000 1.000 

1500403000 15 Wheat, germ 0.500000 1.000 1.000 

1500404000 15 Wheat, bran 0.500000 1.000 1.000 
Fluroxypyr Dietary Exposure and Risk Assessment DP Number: 405555

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Attachment 2. Chronic Dietary (Food and Water) Results

ompany Name Ver. 3.16, 03-08-d

DEEM-FCID Chronic analysis for FLUROXYPYR NHANES 2003-2008 2-day

Residue file name: C:\Documents and Settings\stadayon\My Documents\Work in 

Progress\Fluroxypyr\FLUR_CHRON_FW.R08

 Adjustment factor #2 used.

Analysis Date 08-28-2012/14:12:26 Residue file dated: 08-28-2012/14:10:55

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

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

 Total exposure by population subgroup

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

 Total Exposure

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

 Population mg/kg Percent of 

 Subgroup body wt/day Rfd 

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

Total US Population 0.014731 1.5%

Hispanic 0.014948 1.5%

Non-Hisp-White 0.014940 1.5%

Non-Hisp-Black 0.012199 1.2%

Non-Hisp-Other 0.017401 1.7%

Nursing Infants 0.012936 1.3%

Non-Nursing Infants 0.045000 4.5%

Female 13+ PREG 0.013384 1.3%

Children 1-6 0.026661 2.7%

Children 7-12 0.015023 1.5%

Male 13-19 0.011055 1.1%

Female 13-19/NP 0.011360 1.1%

Male 20+ 0.012939 1.3%

Female 20+/NP 0.013854 1.4%

Seniors 55+ 0.012866 1.3%

All Infants 0.035101 3.5%

Female 13-50 0.013459 1.3%

Children 1-2 0.032830 3.3%

Children 3-5 0.024049 2.4%

Children 6-12 0.015918 1.6%

Youth 13-19 0.011206 1.1%

Adults 20-49 0.013645 1.4%

Adults 50-99 0.013107 1.3%

Female 13-49 0.013459 1.3%

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