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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION

MEMORANDUM

Date: 2/15/11 

SUBJECT: Bromoxynil. Petition for Tolerances in Support of New Uses on Grass and Grain 

Sorghum. Summary of Analytical Chemistry and Residue Data.

PC Codes: 035301, 035302 DP Barcode: D378614

Decision No.: 425581 Registration No.: 264-1023

Petition No.: 9F7678 Regulatory Actions: Section 3 Registration

Risk Assessment Type: NA Case No.: 2070

TXR No.: NA CAS No.: 1689-84-5

MRID No.: NA 40 CFR: 180.324

 

FROM: Nancy Dodd, Chemist

Risk Assessment Branch III

Health Effects Division (7509P)

THROUGH: Leung Cheng, Senior Chemist

Risk Assessment Branch III

Health Effects Division (7509P)

TO: Joanne Miller/Bethany Benbow, RM#23

Registration Division (7505P)

The MRIDs associated with this action (MRIDs 47815001 and 47815002) have been reviewed 

under DP Number 380770 (Toiya Goodlow, 8/17/10). The residue chemistry summary

document is presented here. 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Executive Summary

Bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) is a contact herbicide which is registered for 

application as the octanoic and/or heptanoic acid esters for control of broadleaf weeds in various 

crops. The octanoic and heptanoic esters are rapidly converted to the phenol (bromoxynil). 

Bromoxynil inhibits photosynthetic electron transport and oxidative phosphorylation in 

mitochondria.

Bayer CropScience has proposed Section 3 registration for annual and perennial grasses grown 

for seed, conservation reserve program acres (CRP), and grain sorghum on the HUSKIETM 

Herbicide label. HUSKIETM Herbicide (EPA Registration No. 264-1023) is an emulsifiable 

concentrate which contains 13.4% bromoxynil octanoate, 12.9% bromoxynil heptanoate, 3.3% 

pyrasulfotole, and 70.4% inerts. The formulation contains 1.75 lbs bromoxynil active ingredient 

per gallon.

In support of the proposed uses on grass and grain sorghum, Bayer CropScience has proposed 

tolerances under PP#9F7678 for residues of the herbicide bromoxynil (3,5-dibromo-4-

hydroxybenzonitrile) resulting from the application of its octanoic and/or heptanoic acid ester in 

or on the following raw agricultural commodities: 

Grass, forage ..................................................................................18 ppm

Grass, hay........................................................................................ 5.0 ppm

Sorghum, grain.................................................................................0.2 ppm

HED notes that the proposed tolerances are higher than the established tolerances on these 

commodities. The established tolerances for grass and sorghum commodities are 3.0 ppm for 

grass, forage; 3.0 ppm for grass, hay; 0.5 ppm for sorghum, grain, forage; 0.05 ppm for 

sorghum, grain, grain; and 0.2 ppm for sorghum, grain, stover. The grain of grain sorghum 

contributes to aspirated grain fractions; the established tolerance for grain, aspirated fractions is 

0.3 ppm. 

Tolerances are established under 40 CFR §180.324(a)(1) for residues of the herbicide 

bromoxynil (3.5-dibromo-4-hydroxybenzonitrile) resulting from application of its octanoic 

and/or heptanoic acid ester in or on alfalfa, barley, field and pop corn, flax, garlic, aspirated 

grain fractions, grass, oat, onion, peppermint, rye, sorghum, spearmint, and wheat commodities 

at levels ranging from 0.05 ppm to 9.0 ppm. Tolerances are established under 40 CFR 

§180.324(a)(2) for residues of the herbicide bromoxynil (3.5-dibromo-4-hydroxybenzonitrile) 

and its metabolite 3,5-dibromo-4-hydroxybenzoic acid (DBHA) resulting from application of its 

octanoic and/or heptanoic acid ester in or on cotton commodities at levels ranging from 1.5 to 7.0 

ppm and in egg, milk, and the meat, fat, and meat byproducts of cattle, goat, hog, horse, poultry, 

and sheep at levels ranging from 0.05 to 3.5 ppm.

The nature of the residue in grass and grain sorghum is adequately understood based on 

acceptable metabolism studies on alfalfa, sweet corn, and transgenic (BXN) cotton using 

bromoxynil octanoate. The residue of concern in plants other than cotton is bromoxynil. The 

residues of concern in cotton are bromoxynil and the metabolite 3,5-dibromo-4-hydroxybenzoic 

acid (DBHA).
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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The nature of the residue in livestock is adequately understood for bromoxynil, based on 

acceptable ruminant and poultry metabolism studies using bromoxynil octanoate. As determined 

by an AD HOC meeting of the Residues of Concern Knowledgebase Subcommittee (ROCKS) 

on 2/10/11, bromoxynil is the residue of concern in livestock commodities for the tolerance 

expression while bromoxynil and DBHA are the residues of concern in livestock commodities 

for the risk assessment. 

Adequate analytical methodology is available for tolerance enforcement for bromoxynil per se in 

grass and grain sorghum commodities. Method I in PAM, Vol. II, is a gas liquid 

chromatography/microcoulometric detection (GLC/MCD) method that has undergone a 

successful EPA method validation on wheat grain. Method Ia is the same method except that it

uses gas chromatography/electron capture detection (GC/ECD) for determination of methylated 

bromoxynil.

Adequate analytical methodology is available for tolerance enforcement for bromoxynil per se in 

livestock commodities. Method A is a GC/MCD or GC/ECD method for the analysis of 

bromoxynil per se residues in livestock tissues and is essentially the same as Method I. Method 

B is a GC/ECD method that is also similar to Method I, with modifications to the cleanup 

procedures.

Multiresidue methods data for bromoxynil butyrate and bromoxynil octanoate have been 

submitted. Recovery of bromoxynil octanoate and bromoxynil butyrate using FDA Multiresidue 

Method 303: Method II for Nonfattty Foods (Mills, Onley, Gaither Method) is variable. 

Bromoxynil was not detected through Florisil elution. The data have been forwarded to FDA 

and included in the PESTDATA database. 

Adequate storage stability data are available to support the storage durations and conditions of 

samples from the submitted crop field trial studies on grain sorghum and grass. Storage stability

data are available that demonstrate that bromoxynil residues are stable in the forage, grain, and 

stover of grain sorghum and in the forage, hay, and seed of grass stored frozen at -10°C for 12 

months.

Based on the cattle and poultry feeding studies and the calculated livestock dietary burdens, the 

established livestock tolerances are adequate except for milk. The established livestock 

tolerances are 1 ppm on the fat of cattle, goat, hog, horse, and sheep; 3.5 ppm on meat 

byproducts of cattle, goat, hog, horse, and sheep; 0.5 ppm on meat of cattle, goat, hog, horse, and 

sheep; 0.05 ppm on poultry fat; 0.3 ppm on poultry meat byproducts; 0.05 ppm on poultry meat; 

0.05 ppm on egg; and 0.1 ppm on milk. A higher tolerance of 0.4 ppm must be proposed for 

milk.

The submitted residue data for grass are adequate to fulfill data requirements. The number and 

locations of the crop field trials are in accordance with OPPTS Guideline 860.1500, and the field 

trials reflect the proposed use pattern. The residue data for grass were entered into the Agency’s 

tolerance spreadsheet as specified by the Guidance for Setting Pesticide Tolerances Based on 

Field Trial Data SOP to determine an appropriate tolerance level; see Appendix I. Using the 

tolerance calculator, the residue data support the proposed tolerances of 18 ppm on grass forage

and 5.0 ppm on grass hay. 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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The submitted residue data for grain sorghum are adequate to fulfill data requirements. The 

number and locations of crop field trials are in accordance with OPPTS Guideline 860.1500, and 

the field trials reflect the proposed use pattern. The residue data for grain sorghum were entered 

into the Agency’s tolerance spreadsheet as specified by the Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data SOP to determine an appropriate tolerance level; see 

Appendix I. Using the tolerance calculator, the residue data support the proposed tolerance of 

0.2 ppm on the grain of grain sorghum and also support the established tolerance of 0.2 ppm on 

the stover of grain sorghum. Based on the tolerance calculator, HED is recommending that the 

proposed tolerance of 0.5 ppm on the forage of grain sorghum be increased to 0.8 ppm.

Adequate processing studies on corn, sorghum, and wheat are available to support a tolerance on 

aspirated grain fractions (grain dust). The studies all indicate that residues concentrate in 

aspirated grain fractions.

Because the tolerance on the grain of grain sorghum is being increased from 0.05 ppm to 0.2 

ppm, higher residues may occur in aspirated grain fractions; therefore, the petitioner must submit 

a revised Section F to propose a higher tolerance of 1.2 ppm for grain, aspirated grain fractions.

There are no processed commodities associated with use on grass. 

The processed commodity associated with use on grain sorghum is flour; however, residue data 

are not needed on sorghum flour at this time since it is used exclusively in the United States as a 

component for drywall, and not as either a human food or feedstuff.

Analytical reference standards are available for bromoxynil, bromoxynil heptanoate, and 

bromoxynil octanoate. No analytical reference standard for the cotton metabolite 3,5-dibromo4-hydroxybenzoic acid (DBHA) is available.

In the confined rotational crop study in which soil was treated with 14C-bromoxynil octanoate at 

a rate of 0.41 lb ai, low level residues were found in the rotational crops spinach, beets, and 

wheat. The residues consisted of multiple, polar components.

The field rotational crop studies, together with the confined rotational crop data, are adequate to 

demonstrate that detectable bromoxynil residues would not be expected in crops rotated at 30 

days (or more) following application of bromoxynil octanoate to primary crops on the HuskieTM

Herbicide label. Based on the available bromoxynil rotational crop data, a 30-day plantback 

interval (PBI) is adequate for bromoxynil for all rotational crops planted after application of 

HuskieTM Herbicide.

The petitioner must submit a revised Section F to propose tolerances which reflect the 

recommended tolerance levels and correct commodity definitions as specified in Table 17. 

Because the tolerance on the grain of grain sorghum is being increased from 0.05 ppm to 0.2 

ppm, higher residues may occur in aspirated grain fractions. HED has determined that a higher 

tolerance of 1.2 ppm is needed for grain, aspirated grain fractions.

Based on input of the residue data into the tolerance spreadsheet (Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data), HED is recommending a tolerance of 0.8 ppm for 

sorghum, grain, forage in lieu of the established tolerance of 0.5 ppm.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Based on calculated residues in dairy cattle for the tolerance assessment, the established 

tolerance on milk must be increased from 0.1 ppm to 0.4 ppm. Other livestock tolerances remain 

unchanged.

Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for bromoxynil. Pending submission of a 

revised Section B (see requirements under Directions for Use) and a revised Section F (see 

requirements under Proposed Tolerances), there are no residue chemistry issues that would 

preclude granting permanent tolerances on grass and grain sorghum commodities and 

registration for the requested uses on annual and perennial grasses grown for seed, conservation 

reserve program acres (CRP), and grain sorghum. Tolerance levels for residues of bromoxynil 

are recommended as follow: 

Grass, forage ..................................................................................18 ppm

Grass, hay........................................................................................ 5.0 ppm

Grain, aspirated grain fractions........................................................1.2 ppm

Milk................................................................................................. 0.4 ppm

Sorghum, grain, grain ......................................................................0.2 ppm

Sorghum, grain, forage ....................................................................0.8 ppm

Note: The established tolerance of 0.2 ppm on sorghum, grain, stover is to remain 

unchanged.

A human health risk assessment is forthcoming.

Notes to PM: 

The tolerance expression for bromoxynil in 40 CFR §180.324(a)(1) should be revised 

according to HED’s Interim Guidance on Tolerance Expressions (5/27/09, S. Knizner) to 

state:

“Tolerances are established for residues of bromoxynil, including its metabolites and

degradates, in or on the commodities in the table below. Compliance with the tolerance 

levels specified below is to be determined by measuring only bromoxynil (3,5-dibromo-4-

hydroxybenzonitrile) resulting from application of its octanoic and/or heptanoic acid 

ester.

The tolerance expression for bromoxynil in 40 CFR §180.324(a)(2) should be revised 

according to HED’s Interim Guidance on Tolerance Expressions (5/27/09, S. Knizner) to 

state:

“Tolerances are established for residues of bromoxynil, including its metabolites and 

degradates, in or on the commodities in the table below. Compliance with the tolerance 

levels specified below is to be determined by measuring only bromoxynil (3,5-dibromo-4-

hydroxybenzonitrile) and its metabolite 3,5-dibromo-4-hydroxybenzoic acid (DBHA) 

resulting from application of its octanoic and/or heptanoic acid ester.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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All livestock commodities should be moved from 40 CFR §180.324(a)(2) to 40 CFR 

§180.324(a)(1), leaving only cotton, gin byproducts; cotton, hulls; and cotton, undelinted seed

in 40 CFR §180.324(a)(2). 

Although not required to support the current registration action, an analytical reference 

standard for the cotton metabolite 3,5-dibromo-4-hydroxybenzoic acid (DBHA) must be 

submitted to the repository (OPPTS 860.1650).

OPPTS 860.1200 Directions for Use

A revised Section B/label must be submitted with the following revisions:

a) The grass section of the HUSKIE TM Herbicide label should have an “APPLICATION 

METHODS” section which states the type(s) of application (eg. foliar spray, broadcast spray, 

etc.), the method(s) of application (i.e., ground, air, or both), and the minimum gallons spray

per acre for each method.

b) The sorghum section should either state that aerial applications are not to be made or state 

the minimum spray volume for aerial applications.

c) The label contains rotational crop plantback intervals for some crops but not all crops. A 

30-day rotational crop restriction is adequate for bromoxynil. The petitioner must consider 

rotational crop plantback requirements for all active ingredients on the label and then indicate 

a plantback interval for all crops which are not primary (treated) crops on the label or are not 

already listed in the Crop Rotation Guidelines section of the label.

860.1550 Proposed Tolerances

Because the tolerance on the grain of grain sorghum is being increased from 0.05 ppm to 0.2 

ppm, higher residues may occur in aspirated grain fractions. HED has determined that a higher 

tolerance of 1.2 ppm is needed for grain, aspirated grain fractions.

Based on input of the residue data into the tolerance spreadsheet (Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data), HED is recommending a tolerance of 0.8 ppm for 

sorghum, grain, forage in lieu of the established tolerance of 0.5 ppm.

Based on calculated residues in dairy cattle for the tolerance assessment, the established 

tolerance on milk must be increased from 0.1 ppm to 0.4 ppm. Other livestock tolerance levels

remain unchanged.

The petitioner must submit a revised Section F to propose tolerances which reflect the 

recommended tolerance levels and correct commodity definitions as specified in Table 17.

Background

The chemical structure and nomenclature of bromoxynil is presented in Table 1. The 

physicochemical properties of the technical grade of bromoxynil are presented in Table 2. In 

addition, the chemical names and structures of the two esters and the DBHA metabolite 

referenced herein are presented in Appendix II. 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Table 1. Test Compound Nomenclature.

Chemical Structure

Empirical Formula C7H3Br2NO

Common Name bromoxynil or bromoxynil phenol

Company Experimental 

Name

AE F025943 

IUPAC Name 3,5-dibromo-4-hydroxybenzonitrile

CAS Name 3,5-dibromo-4-hydroxybenzonitrile

CAS Registry Number 1689-84-5 (phenol)

1689-99-2 (octanoate)

56634-95-8 (heptanoate)

End-use Product/EP HuskieTM Herbicide

Chemical Class Benzonitrile Herbicide

Known impurities of 

concern

None

Table 2. Physicochemical Properties of Bromoxynil (Bromoxynil Phenol)

Parameter Value Reference (MRID)

Molecular Weight 276.9 47815001

Melting point/range 190.5°C 47815001

pH @ ambient 3.68 47815001

Density 2.31 g/cm3at 20°C 47815001

Water solubility 0.090 g/L at 25oC 47815001

Solvent solubility (20oC) Heptane

Xylene

Methanol

Octanol

Acetone

Ethyl acetate

Acetonitrile

0.15 g/L

8.8 g/L

80.5 g/L

46.7 g/L

186 g/L

97.7 g/L

51.1 g/L

47815001

Vapor pressure 1.4 Pa at 20C 47815001

Dissociation constant, pKa 3.86 47815001

Octanol/water partition coefficient, 

Log(KOW)

2.90 (Kow = 794) 47815001

UV/visible absorption spectrum Primary λmax = 221.2

Primary λmax = 286.8

47815001

860.1200 Directions for Use

Bayer CropScience has proposed Section 3 registration for annual and perennial grasses grown 

for seed, conservation reserve program acres (CRP), and grain sorghum on the HUSKIETM 

Herbicide label. HUSKIETM Herbicide (EPA Registration No. 264-1023) controls broadleaf 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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weeds and mannagrass in grasses and broadleaf weeds in grain sorghum. HUSKIETM Herbicide 

is an emulsifiable concentrate which contains 13.4% bromoxynil octanoate, 12.9% bromoxynil 

heptanoate, 3.3% pyrasulfotole, and 70.4% inerts. The formulation contains 1.75 lbs bromoxynil 

per gallon.

Table 3. Summary of Directions for Use of Bromoxynil.

Applic. Timing, 

Type, and 

Equipment

Formulation

[EPA Reg. 

No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations1,2,3

Grass

(Grasses Grown for Seed and Conservation Reserve Program Acres)

(Perennial Ryegrass, Annual Ryegrass, Tall Fescue, Fine Fescue, Kentucky Bluegrass, Orchardgrass, and Timothy)
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Table 3. Summary of Directions for Use of Bromoxynil.

Applic. Timing, 

Type, and 

Equipment

Formulation

[EPA Reg. 

No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations1,2,3

Pre-emergence 

and/or postemergence

HUSKIETM 

Herbicide 

(EPA Reg. 

No. 264-

1023)

13.5-15 

oz/A

(0.18-

0.205 lb 

ai/A)

2 30 oz

(0.41 lb ai/A)

Forage: 7

Hay: 30

Use in annual and 

perennial grasses grown 

for seed and 

conservation reserve 

program acres (CRP).

Apply from preemergence to 

established perennial 

ryegrass, annual 

ryegrass, tall fescue, 

fine fescue, Kentucky 

bluegrass and 

orchardgrass. Apply to 

established timothy.

Observe an interval of 

at least 30 days between 

applications.

HUSKIETM Herbicide

may be tank mixed with 

herbicides, insecticides, 

fungicides, and spray 

additives.*

The restricted entry 

interval is 12 hours.

Sorghum, Grain
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Table 3. Summary of Directions for Use of Bromoxynil.

Applic. Timing, 

Type, and 

Equipment

Formulation

[EPA Reg. 

No.]

Applic. 

Rate 

(lb ai/A)

Max. No. 

Applic. per 

Season

Max. Seasonal 

Applic. Rate

(lb ai/A)

PHI

(days)

Use Directions and 

Limitations1,2,3

Postemergence,

Foliar spray, 

Ground 

equipment

HUSKIETM 

Herbicide 

(EPA Reg. 

No. 264-

1023)

12.8-16 

oz/A

(0.18-0.22 

lb ai/A)

2 32 oz

(0.44 lb ai/A)

Forage: 7

Grain: 60

Stover: 60

Apply to sorghum 

between the 3 leaf stage

of growth up to 12 

inches.

Apply in minimum of 

10-15 gallons of water 

per acre, as needed to 

obtain thorough spray 

coverage.

Do not apply through 

any type of irrigation 

system.

Observe an interval of 

at least 11 days between 

applications.

HUSKIETM Herbicide

may be tank mixed with 

herbicides and 

insecticides.** 

Do not apply 

HUSKIETM Herbicide

in a tank mix with 

Lorsban as an 

unacceptable crop 

response may occur.

One pound of 

ammonium sulfate per 

acre may be added to 

optimize herbicidal 

activity.

The restricted entry 

interval is 12 hours.

1 Crop Rotation Plantback Intervals: 

1 month: wheat, barley, oats, rye, and triticale

4 months: alfalfa, millet, grain sorghum, and soybeans

9 months: canola, canaryseed, chickpeas, corn, dry beans, flax, field peas, green beans, green peas, lentils 

(except in MN, MT, ND, and SD), mustards, potatoes, safflower, sunflowers, and sugarbeets

18 months: lentils in MN, MT, ND and SD

2 Grass:

For weed control, HUSKIETM Herbicide may be tank mixed with Puma®, Nortron, Rely, 2.4-D 

ester/amine, AimTM, Bronate AdvancedTM, Buctril®, Curtail M/Curtail®, Dicamba, Goal, Glean, MCPA 

ester/MCPA amine, Sencor®, Starane®/Starane NXT/Starane Ultra, or WideMatchTM.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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For insect control, HUSKIETM Herbicide may be tank mixed with Baythroid®XL, Capture, Lorsban®, 

Mustang MaxTM, or Warrior® Insecticides.

For disease control, HUSKIETM Herbicide may be tank mixed with fungicides such as Absolute, Tilt®, 

Quadris®, QuiltTM, or Bravo.

Some tank mix options require the use of a non-ionic surfactant (NIS). Use the amount of the NIS 

recommended on the tank mix partner label or at a concentration of 0.25-0.5% v/v (1-2 qt per 100 gallons 

of spray solution). At least 80% of the surfactant product must be active non-ionic surfactant.

3 Grain Sorghum:

For grass control, HUSKIETM Herbicide may be tank mixed with 0.25-1.0 lb atrazine per acre. For weed 

control, HUSKIETM Herbicide plus atrazine may be tank mixed with phenoxy broadleaf herbicides such as 

2,4-D or dicamba.

For insect control, HUSKIETM Herbicide may be tank mixed with Baythroid®XL

An unacceptable crop response may occur if HuskieTM Herbicide is applied to acreage that has been 

previously treated with mesotrione.

Sensitivity of sweet sorghum (sorgo), sudangrass, sorghum-sudangrass hybrids, or dual-purpose sorghum 

varieties to HUSKIETM Herbicide is not known and the use of HUSKIETM Herbicide on these sorghum 

types is not recommended.

Conclusions

A revised Section B/label must be submitted with the following revisions:

a) The grass section of the HUSKIE TM Herbicide label should have an “APPLICATION 

METHODS” section which states the type(s) of application (eg. foliar spray, broadcast spray, 

etc.), the method(s) of application (i.e., ground, air, or both), and the minimum gallons spray 

per acre for each method.

b) The sorghum section should either state that aerial applications are not to be made or state 

the minimum spray volume for aerial applications.

c) The label contains rotational crop plantback intervals for some crops but not all crops. A 

30-day rotational crop restriction is adequate for bromoxynil. The petitioner must consider 

rotational crop plantback requirements for all active ingredients on the label and then indicate 

a plantback interval for all crops which are not primary (treated) crops on the label or are not 

already listed in the Crop Rotation Guidelines section of the label.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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860.1300 Nature of the Residue - Plants

Madden, B., 6/24/98, DP Number 246944, Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised 

Human Health Risk Assessment for Bromoxynil

Irene, S., 4/25/97, DP Number 000000, 035301.001, PP#3F04233. New Tolerances for Bromoxynil on Cotton 

Commodities. Changes from HED’s April 8, 1997 Risk Assessment.

Griffin, R., Boyle, K., Fort, F., Hansen, L., Kramer, G., and Robbins, S., 4/8/97, DP Number 231906, PP#3F04233. 

Extension of Conditional Registration for the Use of Bromoxynil on Transgenic Cotton.

Kramer, G.F., 9/17/93, DP Number 189368, PP# 3G04197. Bromoxynil octanoate and heptanoate in or on 

transgenic Bromotol cotton. Evaluation of residue and analytical data for an EUP and temporary tolerances.

No new plant metabolism studies were submitted with this petition. Acceptable metabolism 

studies are available on alfalfa, sweet corn, and transgenic (BXN) cotton using bromoxynil 

octanoate. The nature of the residue in alfalfa, sweet corn, and cotton following application of 

14C-bromoxynil octanoate is adequately understood. The metabolic pathway involves hydrolysis 

of the ester, oxidation of the nitrile group to the acid via the amide, and conjugation; 

debromination occurs in a parallel pathway. Based on these studies, the residue of concern in 

plants other than cotton is the major metabolite, bromoxynil. Because transgenic cotton 

metabolizes bromoxynil primarily to 3,5-dibromo-4-hydroxybenzoic acid [78.6% of the total 

radioactive residues (TRR)], the residues of concern in cotton are bromoxynil and its metabolite 

3,5-dibromo-4-hydroxybenzoic acid (DBHA).

The residues of concern in cotton were reassessed in an AD HOC meeting of the Residues of 

Concern Knowledgebase Subcommittee (ROCKS) on 2/10/11. The Committee confirmed that

DBHA should be included in the tolerance expression for cotton since it is a major residue in 

cotton (78.6% of the TRR) and is an indicator of misuse. 

Based on a study in cotton, the translocation of bromoxynil octanoate is extremely minimal. 

Bromoxynil octanoate (14C-labelled) was applied to a single leaf or boll and harvested after 7 

days (from leaves) or 47 days (from bolls). A very small amount (0.15% or less of the total 

radioactive residue [TRR]) was translocated to adjacent leaves. No residues were found in 

cottonseed.

 

Conclusions

The nature of the residue in grass and grain sorghum is adequately understood based on 

acceptable metabolism studies on alfalfa, sweet corn, and transgenic (BXN) cotton using 

bromoxynil octanoate. The residue of concern in plants other than cotton is bromoxynil. The 

residues of concern in cotton are bromoxynil and its metabolite 3,5-dibromo-4-hydroxybenzoic 

acid (DBHA).
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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860.1300 Nature of the Residue – Livestock

Madden, B., 6/24/98, DP Number 246944, Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised 

Human Health Risk Assessment for Bromoxynil

Swartz, C., 3/19/98, DP Number 244250, Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID 

No. 035302. Issues Discussed by HED’s ChemSAC on 2/25/98.

Irene, S., 4/25/97, DP Number 000000, 035301.001, PP#3F04233. New Tolerances for Bromoxynil on Cotton 

Commodities. Changes from HED’s April 8, 1997 Risk Assessment.

Griffin, R., Boyle, K., Fort, F., Hansen, L., Kramer, G., and Robbins, S., 4/8/97, DP Number 231906, PP#3F04233. 

Extension of Conditional Registration for the Use of Bromoxynil on Transgenic Cotton.

Funk, S., 9/2/92, DP Number 179470, Registration of Bromoxynil Octanoate. GLN 171-4(b): Nature of the Residue 

in Ruminants and Poultry.

No new livestock metabolism studies were submitted with this petition. Ruminant and poultry

metabolism studies are available. The nature of the residue in livestock is adequately understood 

for bromoxynil, based on acceptable ruminant and poultry metabolism studies using bromoxynil 

octanoate.

When 14C-bromoxynil octanoate was administered to lactating goats, 90% of the TRR was 

recovered as bromoxynil per se. The parent compound was found only in milk (1.7% of the 

TRR). DBHA was found only in liver (4% of the TRR); it was found after base hydrolysis of the 

non-extracted liver residue.

When 14C-bromoxynil octanoate was administered to laying hens, 73-100% of the TRR was 

recovered as bromoxynil per se. The parent compound was found only in eggs (4-6% of the 

TRR). Polar unknowns accounted for 3% of the TRR in liver.

 

Residues of concern in livestock were reassessed in an AD HOC meeting of the Residues of 

Concern Knowledgebase Subcommittee (ROCKS) on 2/10/11. The Committee determined that 

the residues of concern in livestock are bromoxynil for the tolerance expression and bromoxynil 

and DBHA for the risk assessment. The Committee determined that DBHA does not need to be 

included in the tolerance expression for livestock commodities for the reasons listed below. 

These conclusions apply to existing and proposed uses only.

1) When livestock are fed bromoxynil octanoate, DBHA is a minor metabolite in livestock, 

present only in liver (4% of the TRR). 

2) Cotton is the only registered/proposed transgenic crop and cotton commodities are not 

driving the dietary burden.

3) DBHA is less toxic than bromoxynil as indicated in the following tests: a Salmonella 

typhimurium Reverse Mutation Assay (Ames Test), a developmental toxicology study

(rat), and a subchronic toxicity study (rat). There is no toxicity concern 

(cancer/noncancer) at anticipated exposure levels. The DEREK indicated a 

polyhalogenated cancer alert but since DBHA is an acid, the concern is eliminated.

4) The effect that conversion of the nitrile group to a carboxyl group has on developmental 

toxicity and liver toxicity is likely to carry over to carcinogenicity as well. The carboxyl 

group will be ionized at physiological pH and this will result in rapid excretion of DBHA 

and retard cellular uptake and migration of DBHA through intracellular membranes to 

interact with receptors associated with carcinogenicity. There is therefore little concern 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 14 of 58

for carcinogenicity for DBHA.

Conclusions

The nature of the residue in livestock is adequately understood, based on acceptable ruminant 

and poultry metabolism studies using bromoxynil octanoate. Bromoxynil is the residue of 

concern in livestock commodities for the tolerance expression while bromoxynil and DBHA are 

the residues of concern in livestock commodities for the risk assessment. 

860.1340 Residue Analytical Methods

Madden, B., 6/24/98, DP Number 246944, Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised

Human Health Risk Assessment for Bromoxynil

Swartz, C., 3/2/98, DP Number 243651, Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID 

No. 03530, Rhône-Poulenc Submission of Additional Field Trials Conducted at Reduced Rates on Transgenic BXN 

Cotton.

Kramer, G.F., 3/11/97, DP Number 232957, ID# 000264-00540. PP# 3F04233. Bromoxynil Octanoate and 

Heptanoate in or on Transgenic BXN Cotton. Amendment of 12/18/96. Submission of Residue Data.

Enforcement Methods

Plants:

Adequate analytical methodology is available for tolerance enforcement for bromoxynil per se in 

plants. Method I in PAM, Vol. II, is a gas liquid chromatography/microcoulometric detection 

(GLC/MCD) method that has undergone a successful EPA method validation on wheat grain. 

This method involves alkaline hydrolysis in methanolic potassium hydroxide to convert residues 

to bromoxynil, cleanup by liquid-liquid partitioning, methylation using diazomethane, further 

cleanup on a Florisil column, and determination by GLC/MCD. Method Ia is the same method

except that it uses gas chromatography/electron capture detection (GC/ECD) for determination 

of methylated bromoxynil.

Livestock:

Adequate analytical methodology is available for tolerance enforcement for bromoxynil per se in 

livestock commodities. Method A is a GC/MCD or GC/ECD method for the analysis of 

bromoxynil per se residues in livestock tissues and is essentially the same as Method I. Method 

B is a GC/ECD method that is also similar to Method I, with modifications to the cleanup 

procedures.

Data Collection Methods

Goodlow, T., 8/17/10, DP Number 380770, Bromoxynil: Review of HUSKIE HERBICIDE – Magnitude of the 

Residue in/on Sorghum and Grass

Samples of sorghum forage, grain, and stover and of grass forage and hay were analyzed for 

residues of bromoxynil using Bayer Method No. BR-001-P05-01. The method hydrolyses the 

esters bromoxynil heptanoate and bromoxynil octanoate to bromoxynil phenol. Bromoxynil 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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standards were corrected for purity and prepared in parent compound molar equivalents during 

initial standard solution preparation, so all residues are reported in parent compound equivalents.

This high performance liquid chromatography/tandem mass spectroscopy (HPLC-MS/MS) 

analytical method quantifies residues of bromoxynil from a single sample using isotope labeled 

internal standards with a multi-level calibration curve. Briefly, a 2.0- or 0.5-g aliquot of sorghum 

matrices was weighed into a 60-mL vial and a methanol solution of potassium hydroxide (5% 

w/v) was added. The sample was heated to 60°C for at least 60 minutes. The samples were 

cooled and an isotopic internal standard was added to the sample extract. A 5-mL aliquot was 

acidified and purified by C18 solid phase extraction (C-18 SPE). The solvent was removed from 

the sample and the residue was reconstituted for analysis by HPLC-MS/MS. HPLC separation 

was performed with an Xterra MSC18 HPLC column, 3.56 um, 50 x 2.1 mm column using 9:1 

water/acetonitrile (ACN) with 0.1% acetic acid (HOAc) and ACN with 0.1% formic acid as the 

mobile phase on a Thermo Finnigan Surveyor HPLC. The HPLC was interfaced to a 

ThermoFinnigan Quantum Ultra tandem mass spectrometer for analyte detection.

The lowest level of method validation was 0.01 ppm in sorghum forage, grain, and stover and in 

grass forage and hay. The limits of detection (LODs) were 0.00246 ppm, 0.00379 ppm, and 

0.00315 ppm for bromoxynil in sorghum forage, grain, and stover, respectively. The LODs were

0.00531 ppm and 0.00287 ppm for bromoxynil in grass forage and grass hay, respectively.

Conclusions

Plants:

Adequate analytical methodology is available for tolerance enforcement for bromoxynil per se in 

grass and grain sorghum commodities. Method I in PAM, Vol. II, is a gas liquid 

chromatography/microcoulometric detection (GLC/MCD) method that has undergone a 

successful EPA method validation on wheat grain. Method Ia is the same method except that it

uses gas chromatography/electron capture detection (GC/ECD) for determination of methylated 

bromoxynil.

The data collection method (Bayer Method No. BR-001-P05-01) is acceptable for data collection 

based on concurrent recoveries. Bromoxynil residues in sorghum forage, grain, and stover and 

in grass forage and hay were quantitated by high performance liquid chromatography/tandem 

mass spectroscopy (HPLC-MS/MS) using stable isotopically labeled bromoxynil as an internal 

standard. The lowest level of method validation (LLMV) for bromoxynil was 0.01 ppm in all 

matrices. 

Livestock:

Adequate analytical methodology is available for tolerance enforcement for bromoxynil per se in 

livestock commodities. Method A is a GC/MCD or GC/ECD method for the analysis of 

bromoxynil per se residues in livestock tissues and is essentially the same as Method I. Method

B is a GC/ECD method that is also similar to Method I, with modifications to the cleanup 

procedures.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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860.1360 Multiresidue Methods

Griffith, F.D., 11/4/92, DP Number 179705, PP#0F3848 - BROMOXYNIL (BUCTRIL®) ON RICE GRAIN AND STRAW. 

REVIEW OF THE MAY 26 AND AUGUST 7, 1992 AMENDMENTS.

Madden, B., 6/24/98, DP Number 246944, Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised 

Human Health Risk Assessment for Bromoxynil

The FDA PESTDATA database (Pesticide Analytical Manual, Vol. I, Appendix I, 3

rd edition, 

1994, revised October 1999) indicates that recovery of bromoxynil octanoate and bromoxynil 

butyrate using FDA Multiresidue Method 303: Method II for Nonfatty Foods (Mills, Onley, 

Gaither Method) is variable. Bromoxynil was not detected through Florisil elution. No data 

were reported for the methyl ether of bromoxynil.

Conclusions

Multiresidue methods data for bromoxynil butyrate and bromoxynil octanoate have been 

submitted. Recovery of bromoxynil octanoate and bromoxynil butyrate using FDA Multiresidue 

Method 303: Method II for Nonfatty Foods (Mills, Onley, Gaither Method) is variable. 

Bromoxynil was not detected through Florisil elution. The data have been forwarded to FDA 

and included in the PESTDATA database. 

860.1380 Storage Stability

Goodlow, T., 8/17/10, DP Number 380770, Bromoxynil: Review of HUSKIE HERBICIDE – Magnitude of the 

Residue in/on Sorghum and Grass

Grain sorghum: The maximum frozen storage interval from sampling to extraction of 

bromoxynil was 351 days for forage, 275 days for grain, and 273 days for stover. All samples 

were analyzed within 3 days of extraction. Storage stability data are available that demonstrate 

bromoxynil residues are stable in sorghum forage, grain and stover stored frozen at -10°C for 12 

months (DP Numbers 204403 and 199274, S. Knizner, 7/14/94; MRID 43108801). 

Grass: The maximum frozen storage interval from sampling to extraction prior to analysis of 

bromoxynil was 350 days for grass forage and 313 days for grass hay. All samples were 

analyzed within 2 days of extraction. Storage stability data are available that demonstrate 

bromoxynil residues are stable in grass forage, hay, and seed stored frozen at -10°C for 12 

months (DP Numbers 204403 and 199274, S. Knizner, 7/14/94; MRID 43108801). These data 

adequately support the storage durations and conditions of samples from the submitted crop field 

trial study. 

The storage conditions and durations of samples from the crop field trials are summarized in 

Table 4.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Table 4. Summary of Storage Conditions and Durations of Samples from Crop Field Trial Studies on 

Bromoxynil

Matrix Maximum Storage 

Temperature1 (°C)

Actual Storage 

Duration2

Interval of Demonstrated Storage Stability3

Grass

Grass forage <0 187 – 350 days 

(6.0 to 11.3 months)

Residues are stable in/on grass forage and hay 

and variety of other crops (i.e. wheat, barley, 

sorghum, and corn) stored frozen at -10°C for 

up to 12 months. Grass hay <0 143 to 313 days

(4.6 to 10.1 months)

Sorghum, Grain

Sorghum Forage <0 179 to 351 days (5.8 to 

11.3 months) Residues are stable in/on sorghum forage, 

grain and stover and a variety of other crops 

(i.e. wheat, barley, grass, and corn) stored 

frozen at -10°C for up to 12 months (MRID 

43108801).

Sorghum Grain <0 166 to 275 days (5.4 to 

8.9 months)

Sorghum Stover <0 166 to 273 days (5.4 to 

8.8 months)

1

Samples were stored at the field site and analytical laboratory at <0°C. The storage temperature at BRP between 

5/16/2008 and 2/5/2009 was not recorded, however, the freezers were working properly and all samples remained 

frozen. 

2

Storage duration is from date of sampling to date of extraction. Grass forage and hay samples were analyzed within 

0 to 2 days of extraction. Sorghum forage, grain and stover samples were analyzed within 1 to 3 days of extraction.

3Refer to DP Numbers 199274/204403, S. Knizner, 7/14/94; MRID 43108801.

Conclusions

Adequate storage stability data are available to support the storage durations and conditions of 

samples from the submitted crop field trial studies on grain sorghum and grass. Storage stability

data are available that demonstrate that bromoxynil residues are stable in the forage, grain, and 

stover of grain sorghum and in the forage, hay, and seed of grass stored frozen at -10°C for 12 

months.

860.1400 Water, Fish, and Irrigated Crops

This guideline topic is not relevant to the proposed uses.

860.1460 Food Handling

This guideline topic is not relevant to the proposed uses.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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860.1480 Meat, Milk, Poultry, and Eggs

Kramer, G.F., 3/11/97, DP Number 232957, Bromoxynil Octanoate and Heptanoate in or on Transgenic BXN 

Cotton. Amendment of 12/18/96. Submission of Residue Data.

Swartz, C., 1/20/98, DP Number 239914, Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID 

No. 035302. Revised Anticipated Residues Assessment Based on Revised Labeling Submitted in Conjunction with 

PP#3F4233 (9/24/97). 

Livestock feed items associated with grass are forage, hay, and silage; livestock feed items 

associated with grain sorghum are grain, forage/silage, stover, and aspirated grain fractions

(Table 1 Feedstuffs, June 2008).

Cattle and poultry feeding studies were previously reviewed (DP Number 232957, G. F. Kramer, 

3/11/97). Results of the feeding studies with both feeding levels and residues reported as 

bromoxynil per se (DP Number 239914, C. Swartz, 1/20/98) are reported below:

Table 5. Average Bromoxynil Octanoate Residues in Cattle Tissues

Feeding Level 

(ppm)

Average Bromoxynil Residues (ppm)

Milk Liver Kidney Fat Muscle

4.2 0.05 1.97 2.26 0.68 0.37

12.6 0.14 4.04 5.89 2.11 0.86

42.0 0.48 10.65 16.26 4.75 2.59

Table 6. Average Bromoxynil Octanoate Residues in Poultry Tissues

Feeding Level 

(ppm)

Average Bromoxynil Residues (ppm)

Liver Muscle Skin & Fat

0.07 0.063 Not analyzed Not analyzed

0.21 0.083 <0.05 <0.05

0.70 0.21 0.05 0.08

1Residues in eggs were not detectable (<0.05 ppm) at the highest feeding level (0.70 ppm).

Residues in milk from the low dose group were nondetectable (<0.05 ppm) prior to day 18 and 

were 0.05 ppm thereafter. Residues in milk from the medium dose group plateaued on day 14 at 

an average of 0.14 ppm. Residues in milk from the high dose group plateaued after 21 days at an 

average of 0.48 ppm

The maximum reasonably balanced dietary burdens (MRBDB) for bromoxynil residues in 

livestock commodities can be calculated as follows. Table 7a applies to the tolerance 

assessment; Table 7b applies to the risk assessment.

Table 7a. Maximum Reasonably Balanced Dietary Burdens for Bromoxynil in Livestock Dietsa

% Diet b Dietary Contributions (ppm)

Feedstuff Type Tolerance, 

ppm

% Dry 

Matter Beef Dairy Poultry Swine Beef Dairy Poultry Swine 

Grass forage R 18 25 Nuc45 Nu Nu -- 32.4 -- --

Barley hay R 9.0 88 10 -- Nu Nu 1.02 -- -- --

Cotton gin byproducts R 7.0 90 5 -- -- -- 0.39 -- -- --

Grain sorghum, grain CC 0.2 86 40 45 75 80 0.093 0.105 0.15 0.16
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Barley grain CC 0.05 88 40 -- -- 5 0.023 -- -- 0.0025

Cotton, undelinted 

seed PC 1.5 88 Nu 10 Nu Nu -- 0.17 -- --

Cotton meal PC 1.5 89 5 -- 20 15 0.084 -- 0.30 0.225

Alfalfa meal PC 0.5 89 Nu -- 5 -- -- -- 0.025 --

Totals 100 100 100 100 1.6 32.7 0.48 0.39

a

 All data are based on Table 1 Feedstuffs (June 2008). Residue levels for beef and dairy are corrected for moisture 

content and are determined by formula: tolerance /%DM x % in diet. Residue levels for poultry and swine are 

considered “as-is” and are determined by formula: tolerance x % in diet. 

b Typical compositions of daily rations for the animals of choice for Table 1 Feedstuffs (June 2008) data follow: 

Feedlot beef have a daily ration of 15% roughage (R), 80% carbohydrate concentrate (CC), and 5% protein 

concentrate (PC) as the slaughter time (last 4-6 months) gets closer. High-production lactating dairy cows have a 

daily ration of 45% R, 45% CC, and 10% PC. A laying hen that will give a steady egg production is fed 75% CC 

and 25% PC. (The laying hen diet should be used to calculate poultry burdens.). A market hog diet that will give 

steady growth consists of 85% CC and 15% PC. 

c

 Nu: Not used

Table 7b. Maximum Reasonably Balanced Dietary Burdens for Bromoxynil in Livestock Diets 

(js/bs revision 10/05/10)a

% Diet b Dietary Contributions (ppm)

Feedstuff Type Tolerance, 

ppm

% Dry 

Matter Beef Dairy Poultry Swine Beef Dairy Poultry Swine 

Barley, hay R 9.0 88 10 45 -- -- 1.02 4.6 -- --

Cotton gin byproducts R 7.0 90 5 -- -- -- 0.39 -- -- --

Grain sorghum, grain CC 0.2 86 40 45 75 80 0.093 0.105 0.15 0.16

Barley grain CC 0.05 88 40 -- -- 5 0.023 -- -- 0.0025

Cotton, undelinted 

seed PC 1.5 88 Nuc

10 Nu Nu -- 0.17 -- --

Cotton meal PC 1.5 89 5 -- 20 15 0.084 -- 0.30 0.225

Alfalfa meal PC 0.5 89 Nu -- 5 -- -- -- 0.025 --

Totals 100 100 100 100 1.6 4.9 0.48 0.39

a

 All data are based on Table 1 Feedstuffs (June 2008). Residue levels for beef and dairy are corrected for moisture 

content and are determined by formula: tolerance /%DM x % in diet. Residue levels for poultry and swine are 

considered “as-is” and are determined by formula: tolerance x % in diet. 

b Typical compositions of daily rations for the animals of choice for Table 1 Feedstuffs (June 2008) data follow: 

Feedlot beef have a daily ration of 15% roughage (R), 80% carbohydrate concentrate (CC), and 5% protein 

concentrate (PC) as the slaughter time (last 4-6 months) gets closer. High-production lactating dairy cows have a 

daily ration of 45% R, 45% CC, and 10% PC. A laying hen that will give a steady egg production is fed 75% CC 

and 25% PC. (The laying hen diet should be used to calculate poultry burdens.). A market hog diet that will give 

steady growth consists of 85% CC and 15% PC. 

c

 Nu: Not used
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Comments: 

1) The proposed label allows use on Conservation Reserve Program (CPR) acres. 

Under this program farmlands are considered retired from active crop planting for a 

period of time to control topsoil erosion usually by a vegetative ground cover. It is 

also used to increase wildlife population across the US. Haying and grazing are 

authorized under certain conditions to improve the quality and performance of the 

CPR cover or provide emergency relief to livestock producers affected by a severe 

drought or natural disaster. In these cases, haying and grazing are only allowed no 

more that one out of every three years. These activities would be used for growing 

cattle, and generally not used for feedlot beef or high production dairy as defined by 

Table 1 Feedstuffs (June 2008). Forage commodities from these areas are not 

considered significant.

2) The proposed label allows use on grass grown for seed. With grass crops the 

purpose is to produce grass seed. Therefore, in grass seed growing areas, grazing 

would not occur, and hay would not be produced. The only feedstuff produced is 

grass straw. In the Pacific NW (to include ID, OR and WA), much of the grass straw 

is sold and shipped to the Orient for livestock feeding (>500,000 tons/yr). Only small 

amounts are fed to US cattle. In addition, other amounts are directed into energy

producing processes. The amount that is fed is used for growing cattle, and not used 

for feedlot beef or high production dairy as defined by Table 1 Feedstuffs (June 

2008). Grass straw from other grass seed producing states allow controlled field 

burning to remove straw. Best estimates using a value of 2.2 tons/A for all varieties 

of U.S. grass seed, approximately 2,000,000 tons of straw would be generated across 

the U.S. Grass straw will not be considered significant.

3) The proposed label allows use on grain sorghum only (grain and forage). Uses on 

other types of sorghum are not allowed. Grain from grain sorghum is included in the 

proposed daily cattle diets.

4) Tolerances are established on cotton, undelinted seed, cotton gin byproducts and 

cotton hulls. The Agency does not consider cotton hulls to be a significant feed item. 

Undelinted cotton seed and cotton gin byproducts are included in the proposed diet.

Table 8. Transfer Coefficients and Calculated Residues of Bromoxynil in Dairy Cattle Commodities

Matrix Feeding Level

(ppm)

Maximum Residues 

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Residues (ppm)2

Milk 4.2 0.05 0.012 32.7 (for tolerance 

assessment)

0.39

4.9 (for risk 

assessment)

0.058

1

 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Table 9. Transfer Coefficients and Calculated Residues of Bromoxynil in Beef Cattle Commodities

Matrix Feeding Level

(ppm)

Maximum Residues 

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Residues (ppm)2

Fat 4.2 0.68 0.16 1.630.26

Kidney 2.26 0.54 0.86

Liver 1.97 0.47 0.75

Muscle 0.37 0.088 0.14

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

3 This value is used for both the tolerance assessment and the risk assessment.

Table 10. Transfer Coefficients and Calculated Residues of Bromoxynil in Poultry Commodities

Matrix Feeding Level

(ppm)

Maximum Residues at 

Feeding Level (ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Residues (ppm)3

Eggs 0.70 <0.0520.071 0.4840.034

Skin/Fat 0.70 0.08 0.11 0.055

Liver 0.21 0.083 0.39 0.19

Muscle 0.70 0.05 0.071 0.034

1

 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Residues in eggs were <0.05 ppm at the highest feeding level (0.70 ppm).

3 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

4 This value is used for both the tolerance assessment and the risk assessment.

Table 11. Transfer Coefficients and Calculated Residues of Bromoxynil in Swine Commodities

Matrix Feeding Level

(ppm)

Maximum Residues 

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Residues (ppm)2

Fat 4.2 0.68 0.16 0.3930.063

Kidney 2.26 0.54 0.21

Liver 1.97 0.47 0.18

Muscle 0.37 0.088 0.034

1

 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

3 This value is used for both the tolerance assessment and the risk assessment.

Conclusions

Based on the cattle and poultry feeding studies and the calculated livestock dietary burdens, the 

established livestock tolerances are adequate except for milk. The established livestock 

tolerances are 1 ppm on the fat of cattle, goat, hog, horse, and sheep; 3.5 ppm on meat 

byproducts of cattle, goat, hog, horse, and sheep; 0.5 ppm on meat of cattle, goat, hog, horse, and 

sheep; 0.05 ppm on poultry fat; 0.3 ppm on poultry meat byproducts; 0.05 ppm on poultry meat; 

0.05 ppm on egg; and 0.1 ppm on milk. A higher tolerance of 0.4 ppm must be proposed for 

milk.

Note: Anticipated residue calculations are attached (Appendix IV) for dietary exposure 

assessment.
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860.1500 Crop Field Trials

Goodlow, T., 8/17/10, DP Number 380770, Bromoxynil: Review of HUSKIE HERBICIDE – Magnitude of the 

Residue in/on Sorghum and Grass

Grass

The raw agricultural commodities associated with grass are forage and hay.

Bayer CropScience has submitted field trial data for the product HUSKIE herbicide on grass 

(Bermuda, bluegrass, and fescue). HUSKIE herbicide is an emulsifiable concentrate mixture 

containing three active ingredients: pyrasulfotole (37.5 g ai/L), bromoxynil (210 g ai/L), and 

mefenpyr-diethyl safener (9.38 g ai/L). Twelve trials were conducted in the United States and 

Canada during the 2008 growing season. The trials encompassed Zones 1 (1 trial in Atlantic 

Provinces, Canada), 2 (1 trial in GA), 3 (1 trial in FL), 4 (1 trial in AR), 5 (1 trial in WI; 1 trial in 

NE), 9 (1 trial in ID), 10 (1 trial in CA), 11 (1 trial in ID; 1 trial in WA), and 12 (1 trial in British 

Columbia, Canada; 1 trial in OR). Each site consisted of one control plot and two treatment 

plots, with one treatment plot for sampling forage and one for sampling hay. The treatment plots 

each received two applications of the formulated product at a target rate of 16.1 fl oz 

HUSKIE/A/application, which corresponds to 0.22 lb bromoxynil/A/application (0.25 kg 

bromoxynil/ha/application). Actual total application rates ranged from 31 to 37 fl oz 

HUSKIE/A/season with a 27- to 30-day re-treatment interval (RTI). Spray volumes ranged from 

10 to 24 gal/A (89 to 225 L/ha). An adjuvant was not used in the spray applications. Grass forage 

samples were collected at target pre-harvest interval (PHI) of 0 days and 7 days. Grass hay

samples were collected at a target PHI of 30 days. A residue decline trial was also conducted at 

one site, in which forage samples were collected at PHIs of 0, 1, 3, 7, 10, and 14 days and hay

samples were collected at PHIs of 20, 25, 30, 36, and 40 days.

Bromoxynil residue was quantitated by LC-MS/MS using stable isotopically labeled bromoxynil 

as an internal standard. The LLMV for bromoxynil was 0.01 ppm in grass forage and grass hay. 

The method is acceptable based on concurrent recoveries.

The maximum frozen storage interval from sampling to extraction prior to analysis of 

bromoxynil was 350 days for grass forage and 313 days for grass hay. All samples were 

analyzed within 2 days of extraction. Storage stability data are available that demonstrate 

bromoxynil residues are stable in grass forage, hay, and seed stored frozen at -10°C for 12 

months (MRID 43108801, D204403 and D199274, S. Knizner). These data adequately support 

the storage durations and conditions of samples from the submitted crop field trial study. 

After two applications of Huskie Herbicide to grass at a total rate of 0.43 to 0.51 lb ai/A for 

bromoxynil, residues of bromoxynil in the grass forage samples ranged from 3.37 ppm to 37.8 

ppm at a PHI of 0 days and from 0.0921 ppm to 14.2 ppm at a PHI of 7 to 11 days. Bromoxynil 

in grass hay samples, collected at a PHI of 28 to 31 days from plots treated with Huskie 

Herbicide a total rate of 0.43 to 0.45 lb ai/A, ranged from below the LLMV (0.01 ppm) to 2.26 

ppm.

Residue decline data showed that residues of bromoxynil decreased with time in grass forage and 

hay. A slight increase in bromoxynil residues was observed in grass hay between the 30 and 35 

day PHI interval.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 23 of 58

TABLE 12. Summary of Residue Data from Crop Field Trials with Bromoxynil

Matrix

Total 

Applic. Rate

lb a.i./A

(kg a.i./ha)

PHI 

(days)

Residue Levels1(ppm)

n Min. Max. HAFT2 Median

(STMdR)

Mean

(STMR) Std. Dev.

Grass

Grass Forage 0.43 - 0.51

(0.48 - 0.57)

0 24 3.37 37.8 37.1 18.2 18.9 11.6

7-11 24 0.0921 14.2 13.7 0.520 2.81 5.03

Grass Hay 0.43 - 0.45

(0.48 - 0.50) 28-31 24 <0.01 2.26 2.05 0.089 0.333 0.58

1 LLMV = 0.01 ppm for grass forage and grass hay. LOD = 0.00531 ppm for forage and 0.00287 ppm for hay.

2 HAFT = Highest Average Field Trial.

Conclusions: The submitted residue data for grass are adequate to fulfill data requirements. The 

number and locations of the crop field trials are in accordance with OPPTS Guideline 860.1500, 

and the field trials reflect the proposed use pattern. 

The residue data for grass were entered into the Agency’s tolerance spreadsheet as specified by 

the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP to determine an 

appropriate tolerance level; see Appendix I. Using the tolerance calculator, the residue data 

support the proposed tolerances of 18 ppm on grass forage and 5.0 ppm on grass hay.

Grain Sorghum

The raw agricultural commodities associated with grain sorghum are grain, forage/silage, stover, 

and aspirated grain fractions.

Bayer CropScience has submitted field trial data for the product HUSKIE herbicide on grain 

sorghum. HUSKIE herbicide is an emulsifiable concentrate mixture containing three active 

ingredients: pyrasulfotole (37.5 g ai/L), bromoxynil (210 g ai/L), and mefenpyr-diethyl safener 

(9.38 g ai/L). Twelve trials were conducted in the United States during the 2008 growing 

season. The trials encompassed Zones 2 (1 trial in GA), 4 (1 trial in MS), 5 (1 trial each in IN, 

IA, OH, MN), 6 (1 trial each in OK, TX), 7 (1 trial in ND), and 8 (l trial each in CO, OK, TX). 

Each site consisted of one control plot and two treatment plots, with one treatment plot for 

sampling forage and one for sampling grain and stover. The treatment plots each received two 

applications of the formulated product at a target rate of 16.1 fl oz HUSKIE/A/application, which 

corresponds to 0.22 lb bromoxynil/A/application (0.25 kg bromoxynil/ha/application). Actual 

total application rates ranged from 32 to 33 fl oz HUSKIE/A/season. The re-treatment interval 

(RTI) ranged from 11 to 16 days and the spray volumes ranged from 12 to 20 gal/A (112 to 188 

L/ha). An adjuvant was not used in the spray applications. Sorghum forage samples were 

collected at target pre-harvest intervals (PHI) of 0 days and 7 days and also at earliest 

commercial harvest (ECH) (BBCH 81, beginning of ripening, to BBCH 87, hard dough), which 

corresponded to PHIs of 32 to 82 days. Sorghum grain and stover samples were collected at a 

target PHI of 60 days. A residue decline trial was also conducted at one site, in which forage 

samples were collected at PHIs of 0, 1, 3, 7, 10, and 14 days with additional samples collected at 

five intervals before, at, and after earliest commercial harvest (ECH-14, ECH-7, ECH, ECH+7, 

and ECH+14 days; actual PHIs were 18, 25, 32, 39, and 46 days). Grain and stover samples were 

collected at five intervals corresponding to target PHIs of 47, 53, 60, 67, and 74 days.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 24 of 58

Bromoxynil residues were quantitated by LC-MS/MS using stable isotopically labeled 

bromoxynil as an internal standard. The LLMV for bromoxynil was 0.01 ppm in all matrices. 

The method is acceptable based on concurrent recoveries. The residues are reported in terms of 

bromoxynil phenol.

The maximum frozen storage interval from sampling to extraction of bromoxynil was 351 days 

for forage, 275 days for grain, and 273 days for stover. All samples were analyzed within 3 days 

of extraction. Storage stability data are available that demonstrate bromoxynil residues are stable 

in sorghum forage, grain and stover stored frozen at -10°C for 12 months (MRID 43108801, 

D204403 and D199274, S. Knizner). These data adequately support the storage durations and 

conditions of samples from the submitted crop field trial study. 

After two applications of Huskie Herbicide to sorghum at a total rate of 0.43 to 0.44 lb ai/A for 

bromoxynil, residues of bromoxynil in the forage samples ranged from 4.16 ppm to 27.2 ppm at 

a PHI of 0 days, from 0.072 ppm to 0.61 ppm at a PHI of 5 to 8 days, and from <LLMV (0.01 

ppm) to 0.30 ppm at ECH (PHI of 32 to 82 days). Residues in grain and stover samples 

collected at a PHI of 56 to 60 days from plots treated at a total rate of 0.43 to 0.44 lb ai/A ranged 

from below the LLMV (0.01 ppm) to 0.11 ppm and from 0.011 ppm to 0.11 ppm, respectively.

Residue decline data showed that residues of bromoxynil decreased with time in/on sorghum 

early forage. The residues also generally decreased with time in/on sorghum forage collected 

around earliest commercial harvest (ECH -14 day to ECH +14 day); however, a spike in residues 

was observed at the ECH -7 day interval. In/on sorghum stover, the residues increased with 

time. The decline of bromoxynil residue with time in/on sorghum grain could not be assessed 

due to residue levels below the LLMV.

TABLE 13. Summary of Residue Data from Crop Field Trials with Bromoxynil

Matrix

Total 

Applic. Rate

lb a.i./A

(kg a.i./ha)

PHI1(days)

Residue Levels2, 3 (ppm)

n Min. Max. HAFT4 Median

(STMdR)

Mean

(STMR)

Std. 

Dev.

Grain Sorghum

Sorghum Forage 0.431 -

0.442

(0.482 -

0.498)

0 24 4.16 27.2 25.2 11.1 12.0 5.21

5 to 8 24 0.072 0.61 0.58 0.28 0.30 0.16

ECH (32 to 82) 24 <0.01 0.30 0.30 <0.01 0.037 0.081

Sorghum Grain 56 to 60 24 <0.01 0.11 0.103 0.011 0.028 0.030

Sorghum Stover 56 to 60 24 0.011 0.11 0.097 0.060 0.061 0.032

1 ECH = Earliest commercial harvest

2 LLMV = 0.01 ppm for forage, grain, and stover. LOD = 0.00246 ppm for forage, 0.00379 ppm for grain, or 

0.00315 for stover. LLMV (0.01 ppm) was used when values were <LLMV.

3 Residues reported as bromoxynil phenol.

4HAFT = Highest Average Field Trial. 

Conclusions: The submitted residue data for grain sorghum are adequate to fulfill data 

requirements. The number and locations of crop field trials are in accordance with OPPTS 

Guideline 860.1500, and the field trials reflect the proposed use pattern. 

The residue data for grain sorghum were entered into the Agency’s tolerance spreadsheet as 

specified by the Guidance for Setting Pesticide Tolerances Based on Field Trial Data SOP to 

determine an appropriate tolerance level; see Appendix I. Using the tolerance calculator, the 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 25 of 58

residue data support the proposed tolerance of 0.2 ppm on the grain of grain sorghum and also 

support the established tolerance of 0.2 ppm on the stover of grain sorghum. Based on the 

tolerance calculator, HED is recommending that the proposed tolerance of 0.5 ppm on the forage 

of grain sorghum be increased to 0.8 ppm.

Grain, Aspirated Grain Fractions

Funk, S., 6/28/94, DP Number 184641, Bromoxynil Octanoate (Chemical 035302; List B; Case 2070). Additional 

Data for Magnitude of the Residue in/on Barley (Grain, Forage, Straw, Grain Dust), Garlic, Corn (Grain Dust), 

and Sorghum (Grain Dust). Processing Studies for Barley, Sorghum, and Corn. 

Swartz, C., 3/6/96, DP Number 195998, Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID 

No. 035302. Magnitude of the residue: Alfalfa; Grasses (Grown for Seed); Wheat Processing/Aspirated Grain 

Fractions.

Residues in aspirated grain fractions must be determined for uses on corn, sorghum, soybeans, 

and wheat. Studies on residues in aspirated grain fractions of barley, corn, sorghum, and wheat

have been previously reviewed. As shown in Table 14 (from DP Number 184641) and Table 15

(from DP Number 195998), these studies indicated that residues concentrate in aspirated grain 

fractions. 

Table 14. Bromoxynil Residues (Detected as Bromoxynil Methyl Ether) in or on Barley, Corn, and 

Sorghum Grain and Processed Fractions following 10x Treatment (5 lb ai/A) with the 2 

lb/gal EC Formulation

Crop

(MRID)

Milling

Process Processed Fraction

Residues Founda

(ppm)

Concurrent

Method

Recovery (%)b

Concentration

Factor

Barley

(42460502)

Dry Grain RAC

Hulls

Pearl barley

Bran

Flour

Grain dust

0.18-0.22

0.40-0.56

0.02-0.04

0.06-0.1

0.02-0.06

0.8-2.0

96

90

86

116

98

114

2.2-2.5x

n/cc

n/c

n/c

4-9.1x

Field corn

(42571401)

Dry Grain RAC

Meal

Grits

Flour

Aspirated (2540)e 

Aspirated (2030)f

Aspirated (other)g

Crude oil

Refined oil

<0.02

<0.02

<0.02

<0.02

0.04-0.07

0.05-0.06

0.07-0.11

<0.02

<0.02

83

82

82

85

80

77

74

71

84

n/cc

n/c

n/c

4-7xd

5-6xd

7-11xd

n/c

n/c

Wet Grain RAC

Starch

Aspirated (2540)e

Aspirated (2030)f

Aspirated (other)g

Crude oil

Refined oil

<0.02

<0.02

0.03-0.07

0.04-0.06

0.08-0.11

<0.02

<0.02

83

78

72

79

90

78

99

n/c

3-7xd

4-6xd

8-11xd

n/c

n/c

Sorghum

(42465401)

Dry Grain RAC

Flour

Grain dust

<0.02-0.03h

<0.02

0.19-0.36h

75

70

93

n/c

12xh
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 26 of 58

Wet Grain RAC

Starch

Grain dust

<0.02

<0.02

0.12-0.29

76

84

81

n/c

--

aThree treated samples analyzed per fraction. Residue values for treated samples were not corrected for concurrent 

recoveries. bAll concurrent method recovery samples fortified at 0.1 ppm with bromoxynil octanoate; method 

recoveries corrected for residues in or on control samples [all <0.02 ppm (nondetectable)]. cn/c = no concentration. 

dAssumes bromoxynil concentration on the rac at 50% of the LOQ, or 0.01 ppm. eAspirated grain particles > screen

size 2540. fAspirated grain particles > screen size 2030. gComposite sample of aspirated grain particles < screen 

size 2030. hResidues were <0.02 ppm (nondetectable) in or on two treated grain samples, and were 0.03 ppm in or 

on a third; the concentration factor is calculated for the dust sample (0.36 ppm) obtained from the grain sample 

bearing detectable residues.

Table 15. Bromoxynil Residues in Wheat Processing Fractions.

Commodity Residues (ppm) a Residue/10 (ppm)b

Grain <0.02, 0.02, 0.03 NA

Bran 0.07, 0.06, 0.08 0.007; 0.006; 0.008

Middlings <0.02 (3) NA

Shorts <0.02 (3) NA

Flour <0.02 (3) NA

Aspirated grain fractions 2.16, 1.55, 1.53 0.216; 0.155; 0.153

a Each residue value represents one sample unless otherwise indicated in parentheses. Residue values were not 

corrected for concurrent method recoveries or residues in untreated samples. Residues represent application at a 

10x rate.

b The tolerance for wheat aspirated grain fractions is based on the residue divided by the degree of exaggeration 

(10x) since no quantifiable residues were found in the grain at 1x, residues were found in the grain at the 

exaggerated rate, and those residues divided by the exaggerated rate (10x) are greater than or equal to twice the 

LOQ of the method (OPPTS 860.1520).

A tolerance for aspirated grain fractions of 0.3 ppm was established based on wheat since wheat 

was determined to yield the highest residues in aspirated grain fractions.

Since the sorghum grain tolerance will increase from 0.05 ppm to 0.2 ppm, residues on sorghum 

aspirated grain fractions will increase. Using the HAFT for sorghum grain of 0.103 from MRID 

47815002 and the concentration factor of 12x from Table 14, the aspirated grain fractions 

tolerance should now be 1.2 ppm.

Conclusions. 

Adequate processing studies on corn, sorghum, and wheat are available to support a tolerance on 

aspirated grain fractions (grain dust). The studies all indicate that residues concentrate in 

aspirated grain fractions.

Because the tolerance on the grain of grain sorghum is being increased from 0.05 ppm to 0.2 

ppm, higher residues may occur in aspirated grain fractions; therefore, the petitioner must submit 

a revised Section F to propose a higher tolerance of 1.2 ppm for grain, aspirated grain fractions.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 27 of 58

860.1520 Processed Food and Feed

There are no processed commodities associated with use on grass. 

The processed commodity associated with use on grain sorghum is flour; however, residue data 

are not needed on sorghum flour at this time since it is used exclusively in the United States as a 

component for drywall, and not as either a human food or feedstuff.

Aspirated grain fractions are discussed under 860.1500.

860.1650 Submittal of Analytical Reference Standards

Analytical reference standards for bromoxynil (expiration date 5/7/2011), bromoxynil heptanoate 

(expiration date 9/15/2018), and bromoxynil octanoate (expiration date 2/13/2017) are currently 

available in the National Pesticide Standards Repository. No analytical reference standard for 

the cotton metabolite 3,5-dibromo-4-hydroxybenzoic acid (DBHA) is available (e-mail from 

Charles Stafford to Nancy Dodd on 10/20/10). 

Conclusions

Analytical reference standards are available for bromoxynil, bromoxynil heptanoate, and 

bromoxynil octanoate. No analytical reference standard for the cotton metabolite 3,5-dibromo4-hydroxybenzoic acid (DBHA) is available.

860.1850 Confined Accumulation in Rotational Crops

Madden, B., 6/24/98, DP Number 246944, Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised 

Human Health Risk Assessment for Bromoxynil

Kramer, G.F., 3/11/97, DP Number 232957, ID# 000264-00540. PP# 3F04233. Bromoxynil Octanoate and 

Heptanoate in or on Transgenic BXN Cotton. Amendment of 12/18/96. Submission of Residue Data.

Swartz, C., 2/15/96, DP Number 204985, Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID 

No. 035302. Guideline Ref. No. 165-2: Rotational Crops, Limited Field Studies.

In a confined rotational crop study conducted by Rhone-Poulenc (MRID No. 00115657, 

Environmental Fate and Effects Division (EFED) Phase 4 Review dated 1/17/91), soil was 

treated with 14C-bromoxynil octanoate in an EC formulation at 0.51 lb ai/A. Ten months after 

treatment, spinach, radishes and oats were planted; 12 months after treatment, soybeans and 

turnips were also planted. Total radioactive residues in spinach soybean trash and oat straw were 

0.02 ppm, while the TRR in all other samples was <0.01 ppm. Since radioactive residues were 

so low, there was no attempt to identify bromoxynil metabolites in rotational crops.

In a confined rotational crop study submitted by Union Carbide (MRID No. 00149623, 1984), 

soil was treated with 14C-bromoxynil octanoate in the UC ME-4 formulation at a rate of 0.41 lb 

ai/A. Rotational crops spinach, beets and wheat were planted at intervals of 35, 120 and 360 

days after soil treatment. Average total radioactive residues [14C-bromoxynil octanoate 

equivalents] in rotational crops samples are presented in Table 16.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 28 of 58

Table 16. Total Radioactive Residues in Rotational Crops (MRID No. 00149623)

Crop 35-Day Samples

(ppm)

120-Day Samples

(ppm)

360-Day Samples

(ppm)

Spinach (leaf) 0.086 0.039 0.087

Beets, tops 0.026 0.012 0.02

Beets, roots 0.04 0.012 0.013

Wheat straw 0.051 0.035 0.06

Wheat hulls 0.054 0.02 0.068

Wheat grain 0.02 <0.01 <0.01

The registrant attempted to characterize/identify the radioactivity found in the 35-day samples. 

Following methanolic base hydrolysis of rotational crops samples, extracts were acidified and 

partitioned into ethyl acetate. Extractable radioactivity ranged from 16-40 %TRR. Analysis of 

the radioactivity using thin layer chromatography (TLC) demonstrated that the radioactivity was 

polar, and consisted of multiple, low-level components.

In the Union Carbide study report, soil metabolism data were also discussed. The petitioner 

indicated that bromoxynil octanoate breaks down rapidly in soils, and is associated with organic 

matter; ultimately, residues are incorporated into natural products. 

Conclusions

In the confined rotational crop study in which soil was treated with 14C-bromoxynil octanoate at 

a rate of 0.41 lb ai, low level residues were found in the rotational crops spinach, beets, and 

wheat. The residues consisted of multiple, polar components.

860.1900 Field Accumulation in Rotational Crops

Madden, B., 6/24/98, DP Number 246944, Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised 

Human Health Risk Assessment for Bromoxynil

Swartz, C., 2/20/96, DP Number 204985, Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID 

No. 035302. Guideline Ref. No. 165-2: Rotational Crops, Limited Field Studies.

Limited rotational crop field trials were conducted in CA and TX (MRID 43279401). Soil was 

treated with Buctril® 2E at 0.5 lb ai/A. Winter wheat, collard greens and radishes were rotated 

into the plots 30 and 120 days after treatment. Samples from the 30-day plots were harvested at 

maturity. Residues were less than the limit of quantitation (<0.02 ppm) in winter wheat forage, 

radish tops and roots, and in collard greens harvested from the 30-day plantback plots; residues 

were less than the limit of detection (<0.01) in wheat grain and straw harvested from the 30-day

interval. Since residues were so low in the 30-day samples, the 120-day samples were not 

analyzed, and 365-day plots were not planted.

Conclusions

The field rotational crop studies, together with the confined rotational crop data, are adequate to 

demonstrate that detectable bromoxynil residues would not be expected in crops rotated at 30 

days (or more) following application of bromoxynil octanoate to primary crops on the HuskieTM
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 29 of 58

Herbicide label. Based on the available bromoxynil rotational crop data, a 30-day plantback 

interval (PBI) is adequate for bromoxynil for all rotational crops planted after application of 

HuskieTM Herbicide.

(Note: Transgenic cotton is not on the HuskieTM Herbicide label. To support the use on 

transgenic cotton (DP Number 23957 (G. Kramer, 3/11/97), a new limited field rotational crop 

study is required. The magnitude of bromoxynil and DBHA should be determined in rotational 

crops planted following treatment of genetically-modified cotton with bromoxynil at the 

maximum use rate of 1.5 lb ai/A.)

860.1550 Proposed Tolerances

Tolerances are established under 40 CFR §180.324(a) for residues of the herbicide bromoxynil 

(3.5-dibromo-4-hydroxybenzonitrile) resulting from application of its octanoic and/or heptanoic 

acid ester in or on alfalfa, barley, field and pop corn, flax, garlic, aspirated grain fractions, grass, 

oat, onion, peppermint, rye, sorghum, spearmint, and wheat commodities at levels ranging from 

0.05 ppm to 9.0 ppm. Tolerances are established under 40 CFR §180.324(b) for residues of the 

herbicide bromoxynil (3.5-dibromo-4-hydroxybenzonitrile) and its metabolite 3,5-dibromo-4-

hydroxybenzoic acid (DBHA) resulting from application of its octanoic and/or heptanoic acid 

ester in or on cotton commodities at levels ranging from 1.5 to 7.0 ppm and in egg, milk, and the 

meat, fat, and meat byproducts of cattle, goat, hog, horse, poultry, and sheep at levels ranging 

from 0.05 to 3.5 ppm.

No maximum residue limits or tolerances are established for bromoxynil by Codex or Mexico. 

Tolerances have been established by Canada for grain of sorghum grain at 0.1 ppm and for milk 

at 0.1 ppm. The Canadian tolerance expression is “3,5-dibromo-4-hydroxybenzonitrile, 

including the metabolite 3,5-dibromo-4-hydroxybenzoic acid”; however, compliance with the 

tolerance levels in the U.S. will be determined by measuring only bromoxynil (3,5-dibromo-4-

hydroxybenzonitrile). 

The petitioner must submit a revised Section F to propose tolerances which reflect the 

recommended tolerance levels and correct commodity definitions as specified in Table 17. 

Because the tolerance on the grain of grain sorghum is being increased from 0.05 ppm to 0.2 

ppm, higher residues may occur in aspirated grain fractions. HED has determined that a higher 

tolerance of 1.2 ppm is needed for grain, aspirated grain fractions.

Based on input of the residue data into the tolerance spreadsheet (Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data), HED is recommending a tolerance of 0.8 ppm for 

sorghum, grain, forage in lieu of the established tolerance of 0.5 ppm.

Based on calculated residues in dairy cattle for the tolerance assessment, the established 

tolerance on milk must be increased from 0.1 ppm to 0.4 ppm. Other livestock tolerance levels 

remain unchanged.

As determined by an AD HOC meeting of the Residues of Concern Knowledgebase 

Subcommittee (ROCKS) on 2/10/11, bromoxynil is the residue of concern in milk and other 

livestock commodities for the tolerance expression while bromoxynil and DBHA are the residues 

of concern in livestock commodities for the risk assessment. 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 30 of 58

Table 17. Tolerance Summary for Bromoxynil.

Commodity

Tolerance (ppm) Comments; Correct Commodity 

Definition Established Proposed Recommended 

Grass, forage 3.0 18 18

Grass, hay 3.0 5.0 5.0

Grain, aspirated fractions 0.3 -- 1.2 Grain, aspirated grain fractions

Milk 0.1 -- 0.4

Sorghum, grain 0.05 0.2 0.2 Sorghum, grain, grain

Sorghum, grain, forage 0.5 -- 0.8

Sorghum, grain, stover 0.2 -- 0.2 

References

DP#: D380770

Subject: Bromoxynil: Review of HUSKIE HERBICIDE – Magnitude of the Residue in/on 

Sorghum and Grass.

From: Toiya Goodlow

To: Cassi Walls

Date: 8/17/10

MRIDs: 47815001, 47815002

DP#: D246944

Subject: Bromoxynil (Case #2070: PC Codes 035301 and 035302): Revised Human Health 

Risk Assessment for Bromoxynil.

From: Barbara Madden

To: Linda Werrell

Date: 6/24/98

MRIDs: NA

DP#: D244250

Subject: Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID No. 

035302. Issues Discussed by HED’s ChemSAC on 2/25/98.

From: Christina Swartz

To: Barbara Madden, Linda Werrell/Kathy Monk, and Tobi Colvin-Snyder

Date: 3/19/98

MRID: None
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 31 of 58

DP#: D243651

Subject: Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID No. 

03530. Rhône-Poulenc Submission of Additional Field Trials Conducted at 

Reduced Rates on Transgenic BXN Cotton.

From: Christina Swartz

To: Jane Smith

Date: 3/2/98

MRIDs: 44458900, 44458902

DP#: D239914

Subject: Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID No. 

035302. Revised Anticipated Residues Assessment Based on Revised Labeling 

Submitted in Conjunction with PP#3F4233 (9/24/97). 

From: Christina Swartz

To: Jane Smith, Linda Werrell/Kathy Monk/Tobi Colvin-Snyder

Date: 1/20/98

MRID: None

DP#: D232957

Subject: ID# 000264-00540. PP# 3F04233. Bromoxynil Octanoate and Heptanoate in or 

on Transgenic BXN Cotton. Amendment of 12/18/96. Submission of Residue 

Data. MRID# 441833-01. Barcode D232957. Chemicals 035302 & 128920. 

Case 049993.

From: G. F. Kramer, Ph.D.

To: R. Griffin/K. Boyle

Date: 3/11/97

MRIDs: 44183301

DP#: D231906

Subject: PP#3F04233. Extension of Conditional Registration for the Use of Bromoxynil 

on Transgenic Cotton. 

From: R. Griffin, K. Boyle, F. Fort, L. Hansen, G. Kramer, and S. Robbins

To: D. Stubbs

Date: 4/8/97

MRID: None

DP#: D204985

Subject: Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID No. 

035302. Guideline Ref. No. 165-2: Rotational Crops, Limited Field Studies.

From: Christina B. Swartz

To: Kathryn Davis

Date: 2/15/96

MRID: 43279401
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 32 of 58

DP#: D195998

Subject: Bromoxynil Octanoate. List B Reregistration Case No. 2070/Chemical ID No. 

035302. Magnitude of the residue: Alfalfa; Grasses (Grown for Seed); Wheat 

Processing/Aspirated Grain Fractions

From: Christina B. Swartz

To: Kathryn Davis

Date: 3/6/96

MRIDs: 42950101, 42950102, and 42950103

DP#: D189368

Subject: PP# 3G04197. Bromoxynil octanoate and heptanoate in or on transgenic 

Bromotol cotton. Evaluation of residue and analytical data for an EUP and 

temporary tolerances. 

From: G.F. Kramer, Ph.D.

To: Robert Taylor/Karen Hicks

Date: 9/17/93

MRIDs: 42677701, 42677702 and 42677703

DP#: D184641, D185636, and D182875

Subject: Bromoxynil Octanoate (Chemical 035302; List B; Case 2070). Additional Data 

for Magnitude of the Residue in/on Barley (Grain, Forage, Straw, Grain Dust), 

Garlic, Corn (Grain Dust), and Sorghum (Grain Dust). Processing Studies for 

Barley, Sorghum, and Corn. 

From: Stephen Funk, Ph.D.

To: Kathryn Davis

Date: 6/28/94

MRIDs: 42540601, 42540602, 42571401, 42465401, and 42460502

DP#: D179705

Subject: PP#0F3848 - BROMOXYNIL (BUCTRIL®) ON RICE GRAIN AND STRAW. REVIEW OF 

THE MAY 26 AND AUGUST 7, 1992 AMENDMENTS.

From: Francis D. Griffith, Jr.

Date: 11/4/92

MRIDs: 42344901, 42344902, and 42433401

DP#: D000000, 035301.001

Subject: PP#3F04233. New Tolerances for Bromoxynil on Cotton Commodities. Changes 

from HED’s April 8, 1997 Risk Assessment.

From: Stephanie Irene

Date: 4/25/97

MRID: None

Attachments: 

Appendix I - International Residue Limit Status sheet 

Appendix II - Chemical Name and Structure Table

Appendix III-Tolerance Assessment Calculations

Appendix IV – Anticipated Residues Calculations for Dietary Exposure Assessment

Template Version April 2008
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 33 of 58

Appendix 1

International Residue Limits

Bromoxynil (035301; 09/15/2010)

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition:

US Canada Mexico2 Codex3

40 CFR 180.324:

Plant: bromoxynil (3,5-dibromo-4-

hydroxybenzonitrile)

Livestock: bromoxynil (3,5-dibromo-4-

hydroxybenzonitrile) and its metabolite 3,5-

dibromo-4-hydroxybenzoic acid (DBHA)

3,5-dibromo-4-

hydroxybenzonitrile, 

including the 

metabolite 3,5-

dibromo-4-

hydroxybenzoic acid

None

Commodity1 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico2 Codex

Grain, aspirated grain fractions 1.2

Grass, forage 18

Grass, hay 5.0

Milk 0.4 0.1

Sorghum, grain, forage 0.8

Sorghum, grain, grain 0.2 0.1

Completed: M. Negussie;09/16/2010

1

Includes only commodities of interest for this action. Tolerance values should be the HED recommendations and 

not those proposed by the applicant.

2 Mexico adopts US tolerances and/or Codex MRLs for its export purposes.

3 * = absent at the limit of quantitation; Po = postharvest treatment, such as treatment of stored grains. PoP = 

processed postharvest treated commodity, such as processing of treated stored wheat. (fat) = to be measured on the 

fat portion of the sample. MRLs indicated as proposed have not been finalized by the CCPR and the CAC.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Appendix II

APPENDIX II. Chemical Names and Structures of Bromoxynil , its Esters and Metabolite. 

Common name;

Company code

Chemical name Chemical structure

bromoxynil 3,5-dibromo-4-hydroxybenzonitrile

bromoxynil octanoate 2.6-dibromo-4-cyanophenyl 

octanoate

bromoxynil heptanoate 2.6-dibromo-4-cyanophenyl 

heptanoate

DBHA 3,5-dibromo-4-hydroxybenzoic acid OH

Br Br

O

HO
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

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Appendix III

Tolerance Assessment Calculations

For each of the crops listed below, the Guidance for Setting Pesticide Tolerances Based on Field 

Trial Data (SOP), along with the tolerance spreadsheet (February 2008 version), was used for 

calculating recommended tolerances. (For n>15, results are the same as for the September 2009 

version.) 

Grass Forage

The dataset used to establish a tolerance for bromoxynil on grass forage consisted of field trial 

data representing total application rates of 0.42-0.51 lb ai/A (2 applications at ~0.22 lb 

ai/A/application) with PHIs of 7-11 days. As specified by the Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data (SOP), the field trial application rates are within 25% of 

the maximum label application rate for grass forage; however, the PHIs of 7-11 days for grass 

forage were not within 25% of the proposed 7- day PHI. The residue values that were entered 

into the tolerance spreadsheet are provided below.

All 24 field trial sample results for grass forage were above the LOQ (>0.01 ppm). Maximum 

likelihood estimation (MLE) procedures were not needed to impute censored values.

Visual inspection of the lognormal probability plot and the results from the approximate ShapiroFrancia Normality test indicate that the dataset for grass forage is not lognormal. The “Mean + 

3SD” method was used to calculate the tolerance for the data set. The tolerance value calculated 

using the “Mean + 3SD” method represents an upper bound estimate of the 89th percentile for 

any distribution. Using the tolerance spreadsheet, the recommended tolerance for grass forage is 

18 ppm. 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 36 of 58

Regulator: EPA

Chemical: bromoxynil

Crop: Grass forage

PHI: 7-11 days

App. Rate: 0.43-0.51 lb ai/A

Submitter: Bayer CropScience

Residues LN(Residues)

Zscores

0.107 -2.23 -0.73

0.106 -2.24 -0.88

0.800 -0.22 0.26

0.620 -0.48 0.16

13.100 2.57 1.04

14.200 2.65 1.95

2.890 1.06 0.88

2.840 1.04 0.73

0.095 -2.35 -1.24

0.098 -2.33 -1.04

0.842 -0.17 0.48

0.500 -0.69 -0.16

0.925 -0.08 0.60

0.837 -0.18 0.37

0.180 -1.71 -0.26

0.171 -1.77 -0.37

13.800 2.62 1.50

13.600 2.61 1.24

0.095 -2.35 -1.50

0.092 -2.38 -1.95

0.505 -0.68 -0.05

0.536 -0.62 0.05

0.162 -1.82 -0.48

0.147 -1.92 -0.60
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 37 of 58

Regulator: EPA

Chemical: bromoxynil

Crop: Grass forage

PHI: 7-11 days

App. Rate: 0.43-0.51 days

Submitter: Bayer CropScience

n: 24

min: 0.09

max: 14.20

median: 0.52

average: 2.80

95th Percentile 99th Percentile 99.9th Percentile

12 15 19

(15) (19) (--)

12 40 140

(40) (170) (--)

5.0

18

3.0

0.8826

0.05 >= p-value > 0.01 : Reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

15.0000

7.5000

3.7500

1.8750

0.9375

0.4688

0.2344

0.1172

0.0586

y = 1.7031x - 0.4864

R

2 = 0.8826

Percentiles

Concentrations

EPA bromoxynil Grass forage 7-11 days 0.43-0.51 days Bayer CropScience
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 38 of 58

Grass Hay

The dataset used to establish a tolerance for bromoxynil on grass hay consisted of field trial data 

representing total application rates of 0.43-0.45 lb ai/A (2 applications at ~0.22 lb 

ai/A/application) with PHIs of 28-31 days. As specified by the Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data (SOP), the field trial application rates and PHIs are within 

25% of the maximum label application rate and minimum label PHI, respectively. The residue 

values that were entered into the tolerance spreadsheet are provided below.

Three of the 24 field trial sample results for grass hay were between the LOD (0.00287) and the 

LOQ (0.01 ppm); the reported values were used. Maximum likelihood estimation (MLE) 

procedures were not used.

Visual inspection of the lognormal probability plot and the results from the approximate ShapiroFrancia Normality test indicate that the dataset for grass hay is lognormal. Since the dataset was 

large (greater than 15 samples) and reasonably lognormal, the minimum of the 95% upper 

confidence limit (UCL) on the 95th percentile and the point estimate of the 99th percentile was 

selected as the tolerance value. Using the tolerance spreadsheet, the recommended tolerance for 

grass hay is 5.0 ppm. 
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 39 of 58

Regulator: EPA

Chemical: Bromoxynil

Crop: Grass hay

PHI: 28-31 days

App. Rate: 0.43-0.45 lb ai/A

Submitter: Bayer CropScience

Residues LN(Residues)

Zscores

0.004 -5.42 -1.95

0.006 -5.04 -1.50

0.008 -4.79 -1.24

0.063 -2.76 -0.60

0.084 -2.47 -0.05

0.034 -3.38 -0.73

0.028 -3.59 -0.88

0.848 -0.16 1.24

0.772 -0.26 1.04

0.075 -2.59 -0.26

0.071 -2.64 -0.37

0.093 -2.37 0.05

0.099 -2.31 0.16

0.012 -4.45 -1.04

0.189 -1.67 0.48

0.374 -0.98 0.88

1.850 0.62 1.50

2.260 0.82 1.95

0.346 -1.06 0.73

0.258 -1.35 0.60

0.183 -1.70 0.37

0.175 -1.74 0.26

0.064 -2.76 -0.48

0.083 -2.49 -0.16
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 40 of 58

Regulator: EPA

Chemical: Bromoxynil

Crop: Grass hay

PHI: 28-31 days

App. Rate: 0.43-0.45 lb ai/A

Submitter: Bayer CropScience

n: 24

min: 0.00

max: 2.26

median: 0.09

average: 0.33

95th Percentile 99th Percentile 99.9th Percentile

1.3 1.7 2.5

(1.7) (2.5) (--)

1.6 5.0 18

(5.0) (25) (--)

0.70

2.5

0.50

0.9776

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

3.0000

1.5000

0.7500

0.3750

0.1875

0.0938

0.0469

0.0234

0.0117

0.0059

0.0029

y = 1.7005x - 2.2739

R2 = 0.9776

Concentrations

Percentiles

Lognormal Probability Plot

EPA Bromoxynil Grass hay 28-31 days ...
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 41 of 58

Sorghum Grain

The dataset used to establish a tolerance for bromoxynil on sorghum grain consisted of field trial 

data representing a total application rate of 0.44 lb ai/A (2 applications at 0.22 lb 

ai/A/application) with PHIs of 56-60 days. As specified by the Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data (SOP), the field trial application rates and PHIs are within 

25% of the maximum label application rate and minimum label PHI, respectively. The residue 

values that were entered into the tolerance spreadsheet are provided below.

Eleven of the 24 field trial sample results for sorghum grain were below the LOQ (<0.01 ppm). 

Maximum likelihood estimation (MLE) procedures were needed to impute censored values.

Visual inspection of the lognormal probability plot and the results from the approximate ShapiroFrancia Normality test indicate that the dataset for sorghum grain is lognormal. Since the dataset 

was large (greater than 15 samples) and reasonably lognormal, the minimum of the 95% upper 

confidence limit (UCL) on the 95th percentile and the point estimate of the 99th percentile was 

selected as the tolerance value. Using the tolerance spreadsheet, the recommended tolerance for 

sorghum grain is 0.20 ppm.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 42 of 58

Regulator: EPA

Chemical: Bromoxynil

Crop: Sorghum grain

PHI: 56-60 days

App. Rate: 0.44 lb ai/A

Submitter: Bayer CropScience

Residues LN(Residues)

Zscores

0.003 -5.72 -1.95

0.004 -5.47 -1.50

0.005 -5.31 -1.24

0.006 -5.18 -1.04

0.006 -5.08 -0.88

0.007 -4.99 -0.73

0.007 -4.91 -0.60

0.008 -4.84 -0.48

0.008 -4.78 -0.37

0.009 -4.72 -0.26

0.009 -4.66 -0.16

0.013 -4.38 0.16

0.011 -4.48 0.05

0.035 -3.37 0.60

0.040 -3.21 0.88

0.082 -2.50 1.24

0.067 -2.71 1.04

0.018 -4.02 0.26

0.019 -3.99 0.37

0.010 -4.59 -0.05

0.105 -2.25 1.95

0.101 -2.29 1.50

0.035 -3.34 0.73

0.030 -3.52 0.48
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 43 of 58

Regulator: EPA

Chemical: Bromoxynil

Crop: Sorghum grain

PHI: 56-60 days

App. Rate: 0.44 lb ai/A

Submitter: Bayer CropScience

n: 24

min: 0.00

max: 0.11

median: 0.01

average: 0.03

95th Percentile 99th Percentile 99.9th Percentile

0.08 0.10 0.15

(0.10) (0.15) (--)

0.09 0.20 0.40

(0.20) (0.45) (--)

0.08

0.15

0.06

0.9390

p-value > 0.05 : Do not reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

0.0625

0.0313

0.0156

0.0078

0.0039

0.0020

y = 1.0433x - 4.1798

R2 = 0.939

Concentrations

Percentiles

Lognormal Probability Plot

EPA Bromoxynil Sorghum grain 56-60 days ...
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 44 of 58

Sorghum Forage

The dataset used to establish a tolerance for bromoxynil on sorghum forage consisted of field 

trial data representing a total application rate of 0.43-0.44 lb ai/A (2 applications at ~0.22 lb 

ai/A/application) with PHIs of 5-8 days. As specified by the Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data (SOP), the field trial application rates and PHIs are within 

25% of the maximum label application rate and minimum label PHI, respectively. The residue 

values that were entered into the tolerance spreadsheet are provided below.

All 24 field trial sample results for sorghum forage were above the LOQ (>0.01 ppm). 

Maximum likelihood estimation (MLE) procedures were not needed to impute censored values.

Visual inspection of the lognormal probability plot and the results from the approximate ShapiroFrancia Normality test indicate that the dataset for sorghum forage is not lognormal. 

The “Mean + 3SD” method was used to calculate the tolerance for the data set. The tolerance 

value calculated using the “Mean + 3SD” method represents an upper bound estimate of the 89th

percentile for any distribution. Using the tolerance spreadsheet, the recommended tolerance for 

sorghum forage is 0.80 ppm.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 45 of 58

Regulator: EPA

Chemical: bromoxynil

Crop:

Sorghum 

forage

PHI: 5-8 days

App. Rate: 0.43-0.44 lb ai/A

Submitter: Bayer CropScience

Residues LN(Residues)

Zscores

0.072 -2.64 -1.95

0.072 -2.63 -1.50

0.107 -2.23 -0.73

0.103 -2.27 -0.88

0.469 -0.76 0.88

0.411 -0.89 0.37

0.203 -1.59 -0.48

0.169 -1.78 -0.60

0.465 -0.77 0.73

0.471 -0.75 1.04

0.284 -1.26 -0.05

0.325 -1.12 0.26

0.083 -2.49 -1.24

0.098 -2.32 -1.04

0.282 -1.27 -0.16

0.418 -0.87 0.60

0.542 -0.61 1.50

0.609 -0.50 1.95

0.515 -0.66 1.24

0.417 -0.87 0.48

0.284 -1.26 0.05

0.268 -1.32 -0.37

0.279 -1.28 -0.26

0.297 -1.21 0.16
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 46 of 58

Regulator: EPA

Chemical: bromoxynil

Crop: Sorghum forage

PHI: 5-8 days

App. Rate: 0.43-0.44 lb ai/A

Submitter: Bayer CropScience

n: 24

min: 0.07

max: 0.61

median: 0.28

average: 0.30

95th Percentile 99th Percentile 99.9th Percentile

0.60 0.70 0.90

(0.70) (0.90) (--)

0.80 1.3 2.5

(1.3) (2.5) (--)

1.0

0.80

1.5

0.9020

0.05 >= p-value > 0.01 : Reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

0.0625

y = 0.6767x - 1.3899

R

2 = 0.902

Percentiles

Concentrations

EPA bromoxynil Sorghum forage 5-8 days 0.43-0.44 lb ai/A Bayer CropScience
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 47 of 58

Sorghum Stover

The dataset used to establish a tolerance for bromoxynil on sorghum stover consisted of field 

trial data representing a total application rate of 0.44 lb ai/A (2 applications at 0.22 lb 

ai/A/application) with PHIs of 56-60 days. As specified by the Guidance for Setting Pesticide 

Tolerances Based on Field Trial Data (SOP), the field trial application rates and PHIs are within 

25% of the maximum label application rate and minimum label PHI, respectively. The residue 

values that were entered into the tolerance spreadsheet are provided below.

All 24 field trial sample results for sorghum forage were above the LOQ (>0.01 ppm). 

Maximum likelihood estimation (MLE) procedures were not needed to impute censored values.

Visual inspection of the lognormal probability plot and the results from the approximate ShapiroFrancia Normality test indicate that the dataset for sorghum stover is not lognormal. 

The “Mean + 3SD” method was used to calculate the tolerance for the data set. The tolerance 

value calculated using the “Mean + 3SD” method represents an upper bound estimate of the 89th

percentile for any distribution. Using the tolerance spreadsheet, the recommended tolerance for 

sorghum stover is 0.20 ppm.
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 48 of 58

Regulator: EPA

Chemical: bromoxynil

Crop:

Sorghum 

stover

PHI: 56-60 days

App. Rate: 0.44 lb ai/A

Submitter: Bayer CropScience

Residues LN(Residues)

Zscores

0.011 -4.52 -1.50

0.015 -4.19 -1.04

0.018 -4.02 -0.88

0.023 -3.79 -0.73

0.075 -2.60 0.37

0.074 -2.61 0.26

0.103 -2.27 1.24

0.061 -2.79 0.05

0.059 -2.83 -0.05

0.088 -2.44 0.88

0.108 -2.23 1.50

0.085 -2.47 0.60

0.053 -2.95 -0.48

0.059 -2.83 -0.16

0.013 -4.35 -1.24

0.011 -4.55 -1.95

0.082 -2.50 0.48

0.110 -2.21 1.95

0.058 -2.85 -0.37

0.087 -2.45 0.73

0.049 -3.02 -0.60

0.059 -2.83 -0.26

0.101 -2.29 1.04

0.062 -2.79 0.16
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 49 of 58

Regulator: EPA

Chemical: bromoxynil

Crop: Sorghum stover

PHI: 56-60 days

App. Rate: 0.44 lb ai/A

Submitter: Bayer CropScience

n: 24

min: 0.01

max: 0.11

median: 0.06

average: 0.06

95th Percentile 99th Percentile 99.9th Percentile

0.15 0.15 0.20

(0.15) (0.20) (--)

0.20 0.30 0.60

(0.30) (0.60) (--)

0.20

0.20

0.35

0.8357

p-value <= 0.01: Reject lognormality assumption

Approximate 

Shapiro-Francia 

Normality Test 

EU Method I

Normal

UCLMedian95th

95/99 Rule

EU Method II

Distribution-Free

Mean+3SD

Lognormal Probability Plot

0.1 1 2 5 10 20 30 50 70 80 90 95 98 99 99.9

1.0000

0.5000

0.2500

0.1250

0.0625

0.0313

0.0156

0.0078

y = 0.7241x - 3.0143

R

2 = 0.8357

Percentiles

Concentrations

EPA bromoxynil Sorghum stover 56-60 days 0.44 lb ai/A Bayer CropScience
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 50 of 58

Appendix IV

Livestock Anticipated Residue Calculations for Dietary Exposure Assessment

Livestock Anticipated Residues - Chronic and Cancer

Table 1. Livestock Anticipated Residues for Chronic and Cancer Assessments

Commodity Recommended/

Established 

Tolerance (ppm)

Average Field 

Trial Residue 

(ppm)

% Crop 

Treated

(average)

Anticipated Residue in 

DEEM Run (ppm)

Plant Commodities

Alfalfa, hay

Alfalfa, meal

0.5

--

0.13

---

5

<1

--

--

0.0013

Barley, grain 0.05 0.011

20 0.002

Barley, hay 9.0 0.438

20 0.086

Corn, field, grain 0.05 0.017<2.5 0.00025

Corn, pop, grain 0.05 0.017<2.5 0.00025

Cotton, gin byproducts 7.0 3.26

<2.5 0.08

Cotton, meal -- 0.106

<2.5 0.0025

Cotton, undelinted seed 1.5 0.306

<2.5 0.0075

Flax, seed 0.1 <0.019100 0.01

Garlic 0.1 0.01250 0.005

Oat, grain 0.05 0.0115 0.0005

Onion, bulb 0.1 0.01255 0.0055

Peppermint, hay

Peppermint, oil

0.1

--

--

0.033

100

--

--

0.03

Rye, grain 0.05 0.011100 0.01

Sorghum, grain, grain 0.2 0.0284

<2.5 0.0007

Spearmint, hay

Spearmint, oil

0.1

--

--

0.033

100

--

--

0.03

Wheat, grain 0.05 0.01115 0.0015

Livestock Commodities

Cattle, fat 1 --- 0.0024

Cattle, meat byproducts 3.5 Kidney 0.0081

Liver 0.0070

Cattle, meat 0.5 0.0013

Egg 0.05 0.000078

Goat, fat 1 0.0024

Goat, meat byproducts 3.5 Kidney 0.0081

Liver 0.0070

Goat, meat 0.5 0.0013

Hog, fat 1 0.00015

Hog, meat byproducts 3.5 Kidney 0.00051

Liver 0.00044

Hog, meat 0.5 0.000083

Horse, fat 1 0.0024

Horse, meat byproducts 3.5 Kidney 0.0081

Liver 0.0070

Horse, meat 0.5 0.0013

Milk 0.4 0.00054

Poultry, fat 0.05 0.00013

Poultry, meat byproducts 0.3 Liver 0.00099
Bromoxynil Summary of Analytical Chemistry and Residue Data DP#: 378614

Page 51 of 58

Poultry, meat 0.05 0.000078

Sheep, fat 1 0.0024

Sheep, meat byproducts 3.5 Kidney 0.0081

Liver 0.0070

Sheep, meat 0.5 0.0013

1 DP Number 235876, C. Swartz, 5/14/97, DP Number 234836, C. Swartz, 4/3/97, DP Number 233336, C. Swartz, 

3/20/97, and DP Number 228201, C. Swartz, 7/29/96. Residue data for wheat and barley grains were translated to 

oats and rye. All residues in wheat and barley grains were <0.02 ppm (<LOQ), except for one residue of 0.03 ppm 

in barley grain which was considered to be anomalous. Therefore, the anticipated residue for grain of barley, oat, 

rye and wheat is 0.01 ppm, or 1⁄2 LOQ (LOQ = 0.02 ppm). Since residues do not concentrate in processed 

commodities of cereal grains, the anticipated residue of 0.01 ppm should be used for the processed commodities of 

cereal grains in DEEM.

2 DP Number 235876, C. Swartz, 5/14/97, DP Number 234836, C. Swartz, 4/3/97, DP Number 233336, C. Swartz, 

3/20/97, and DP Number 228201, C. Swartz, 7/29/96. Residue data on onions were translated to garlic. Residues 

on onions were <0.02 ppm (<LOQ). Therefore, the anticipated residue for onions and garlic is 0.01 ppm, or 1⁄2 LOQ 

(LOQ = 0.02 ppm).

3 DP Number 235876, C. Swartz, 5/14/97, DP Number 234836, C. Swartz, 4/3/97, and DP Number 233336, C. 

Swartz, 3/20/97. A processing reduction factor of 3x applies to mint oil.

4 DP Number 380770, T. Goodlow, 8/17/10, MRID 47815002 (grain sorghum) and MRID 47815001 (grass). The 

average residue was used for the chronic assessment.

5 DP Number 195998, C. Swartz, 3/6/96, MRIDs 00150382, 42950101; MRID 44386601. In the calculation of the 

average residues for alfalfa hay, 0.02 ppm was used for residues reported as <0.02 ppm. For alfalfa meal, the alfalfa

hay residues and percent crop treated values are used (OPPTS 860.1000).

6 DP Number 44458900, C. Swartz, 3/2/98. A 0.3x reduction factor is applicable to cottonseed meal based on a 

processing study. Residues reflect the maximum seasonal rate of 1.5 lb ai/A and a 75-day PHI.

7 DP Number 191340, C. Swartz, 10/24/94, MRID 42757601 and D183667, S. Knizner, 11/13/92, MRID 42501601; 

MRID 44386601. All residues in corn grain were <0.02 ppm (<LOQ). Therefore, the anticipated residue for corn 

grain is 0.01 ppm, or 1⁄2 LOQ (LOQ = 0.02 ppm).

8

 MRID 44386601. The residue data on barley hay which are used reflect the recommended 45-day PHI. 

9 DP Number 178167, S. Knizner, 10/29/92, MRID 42283201). All residues in flax seed were <0.02 ppm. 

Therefore, the anticipated residue for flax seed is 0.01 ppm, or 1⁄2 LOQ (LOQ = 0.02 ppm). Since residues do not 

concentrate in processed commodities of flax seed, the anticipated residue of 0.01 ppm should be used for the 

processed commodities of flax seed.
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Livestock Anticipated Residues - Acute

Table 2. Livestock Anticipated Residues for Acute Assessments

Commodity Established/

Recommended Tolerance 

(ppm)

Residue to be Used in Acute DEEM 

Run

Alfalfa, hay

Alfalfa, meal (partially blended)

0.5

---

5

HAFT 0.255

MAX 0.385

AV 0.135

Barley, grain (blended) 0.05 0.011

Barley, hay (partially blended) 9.0 HAFT 3.78

MAX 4.298

AV 0.438

Corn, field, grain 0.05 0.017

Corn, pop, grain 0.05 0.017

Cotton, gin byproducts (partially 

blended)

7.0 HAFT 6.46

MAX 6.56

AV 3.26

Cotton, meal10 (blended) -- HAFT 0.316

MAX 0.336

AV 0.106

Cotton, undelinted seed (blended) 1.5 HAFT 1.036

MAX 1.116

AV 0.306

Flax, seed 0.1 0.019

Garlic 0.1 0.12

Oat, grain 0.05 0.011

Onion, bulb 0.1 0.12

Peppermint, hay

Peppermint, oil

0.1

--

3

--

0.033

Rye, grain 0.05 0.011

Sorghum, grain, grain (blended) 0.2 HAFT 0.1034

MAX 0.114

AV 0.0284

Spearmint, hay

Spearmint, oil

0.1

--

3

--

0.033

Wheat, grain 0.05 0.011

Livestock Commodities

Cattle, fat 1 0.13

Cattle, meat byproducts 3.5 Kidney 0.43

Liver 0.38

Cattle, meat 0.5 0.070

Egg 0.05 0.0038

Goat, fat 1 0.13

Goat, meat byproducts 3.5 Kidney 0.43

Liver 0.38

Goat, meat 0.5 0.070

Hog, fat 1 0.0062

Hog, meat byproducts 3.5 Kidney 0.020

Liver 0.018

Hog, meat 0.5 0.0033

Horse, fat 1 0.13

Horse, meat byproducts 3.5 Kidney 0.43

Liver 0.38

Horse, meat 0.5 0.070
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Milk 0.4 0.0032

Poultry, fat 0.05 0.0061

Poultry, meat byproducts 0.3 Liver 0.048

Poultry, meat 0.05 0.0038

Sheep, fat 1 0.13

Sheep, meat byproducts 3.5 Kidney 0.43

Liver 0.38

Sheep, meat 0.5 0.070

1 DP Number 235876, C. Swartz, 5/14/97, DP Number 234836, C. Swartz, 4/3/97, DP Number 233336, C. Swartz, 

3/20/97, and DP Number 228201, C. Swartz, 7/29/96. Residue data from wheat and barley were translated to oats 

and rye and also used for corn grain. All residues were <0.02 ppm (<LOQ), except for one residue of 0.03 ppm in 

barley grain which was considered to be anomalous. Since barley, oats, and wheat grain are considered to be 

blended, the anticipated residue for the grain of barley, oats, rye and wheat for the acute assessment is 0.01 ppm, or 

1⁄2 LOQ (LOQ = 0.02 ppm). Since residues do not concentrate in processed commodities of cereal grains, the 

anticipated residue of 0.01 ppm should be used for the processed commodities of cereal grains in DEEM. 

2 DP Number 235876, C. Swartz, 5/14/97, DP Number 234836, C. Swartz, 4/3/97, and DP Number 233336, C. 

Swartz, 3/20/97. Since garlic and onions are not considered to be blended, the tolerance level of 0.1 ppm should be 

used for the acute assessment.

3 DP Number 235876, C. Swartz, 5/14/97, DP Number 234836, C. Swartz, 4/3/97, DP Number 233336, C. Swartz, 

3/20/97. A separate tolerance is not established for mint oil since residues decrease on processing. A processing 

reduction factor of 3x applies to mint oil (0.1 ppm x 1/3 = 0.03 ppm).

4 DP Number 380770, T. Goodlow, 8/17/10, MRID 47815002 (grain sorghum). 

5 DP Number 195998, C. Swartz, 3/6/96, MRIDs 00150382, 42950101 (alfalfa); MRID 44386601. In the 

calculation of the average residues for alfalfa hay, 0.02 ppm was used for residues reported as <0.02 ppm. For 

alfalfa meal, the alfalfa hay residues are used (OPPTS 860.1000).

6 DP Number 44458900, C. Swartz, 3/2/98. A 0.3x reduction factor is applicable to cottonseed meal based on a 

processing study. Residues reflect the maximum seasonal rate of 1.5 lb ai/A and a 75-day PHI.

7 DP Number 191340, C. Swartz, 10/24/94, MRID 42757601 and DP Number 183667, S. Knizner, 11/13/92, MRID 

42501601 (corn). All residues in corn grain were <0.02 ppm (<LOQ). Therefore, the anticipated residue for corn 

grain is 0.01 ppm, or 1⁄2 LOQ (LOQ = 0.02 ppm).

8 Barley. MRID 44386601. The residue data on barley hay which are used reflect the recommended 45-day PHI. 

9 DP Number 178167, S. Knizner, 10/29/92, MRID 42283201. All residues in flax seed were <0.02 ppm. Since flax 

is considered to be blended, the anticipated residue for flax seed for the acute assessment is 0.01 ppm, or 1⁄2 LOQ 

(LOQ = 0.02 ppm). Since residues do not concentrate in processed commodities of flax seed, the anticipated residue 

of 0.01 ppm should be used for the processed commodities of flax seed.
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Dairy Cattle and Poultry Feeding Studies

Cattle and poultry feeding studies were previously reviewed (DP Number 232957, G. F. Kramer, 

3/11/97). Results of the feeding studies with both feeding levels and residues reported as 

bromoxynil per se (DP Number 239914, C. Swartz, 1/20/98) are reported below:

Table 3. Average Bromoxynil Residues in Cattle Tissues

Feeding Level 

(ppm)

Average Bromoxynil Residues (ppm)

Milk Liver Kidney Fat Muscle

4.2 0.05 1.97 2.26 0.68 0.37

12.6 0.14 4.04 5.89 2.11 0.86

42.0 0.48 10.65 16.26 4.75 2.59

Table 4. Average Bromoxynil Residues in Poultry Tissues

Feeding Level 

(ppm)

Average Bromoxynil Residues (ppm)

Liver Muscle Skin & Fat

0.07 0.063 Not analyzed Not analyzed

0.21 0.083 <0.05 <0.05

0.70 0.21 0.05 0.08

1Residues in eggs were not detectable (<0.05 ppm) at the highest feeding level (0.70 ppm).

Calculation of Anticipated Residues for Livestock Commodities - Chronic and Cancer

Assessments

Table 5. Livestock Feed Items for Chronic Assessment

Commodity Recommended/

Established 

Tolerance (ppm)

Average Field 

Trial Residue 

(ppm)

% Crop 

Treated

(average)

Anticipated 

Residue (ppm)

Alfalfa, meal --

1

0.13 <1 0.0013

Barley, grain 0.05 0.01 20 0.002

Barley, hay 9.0 0.43 20 0.086

Cotton, gin byproducts 7.0 3.2 <2.5 0.08

Cotton, meal --

2

0.10 <2.5 0.0025

Cotton, undelinted seed 1.5 0.30 <2.5 0.0075

Sorghum, grain, grain 0.2 0.028 <2.5 0.0007

1 Residues in alfalfa hay are used for alfalfa meal. In this table, the alfalfa hay tolerance is used for alfalfa meal.

2 No separate tolerance is established for cotton meal. A 0.3x reduction factor is applied to undelinted cotton seed 

residues to obtain average residues in cotton meal.
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Table 6. Bromoxynil Dietary Contributions for Chronic Assessment using Average Residues from Field Trials as 

Anticipated Residues (AR)

% Diet Dietary Contributions (ppm)

Feedstuff Type AR, ppm1 % Dry 

Matter Beef Dairy Poultry Swine Beef Diary Poultry2

Swine2

Barley, hay R 0.086 88 10 45 -- -- 0.0098 0.044 -- --

Cotton byproducts R 0.08 90 5 -- -- -- 0.0044 -- -- --

Grain sorghum, grain CC 0.0007 86 40 45 75 80 0.00032 0.00036 0.00052 0.00056

Barley grain CC 0.002 88 40 -- -- 5 -- --

Cotton, undelinted 

seed PC 0.0075 88 Nu 10 Nu Nu -- 0.00085 -- --

Cotton meal PC 0.0025 89 5 -- 20 15 0.00014 -- 0.00050 0.00038

Alfalfa meal PC 0.0013 89 Nu -- 5 -- -- -- 0.000065 --

Totals 100 100 100 100 0.015 0.045 0.0011 0.00094

1The anticipated residues for livestock feed items are the average residues from field trials.

2 Poultry and swine calculations do not include division by percent dry matter.

Calculation of Anticipated Residues for Livestock Commodities – Acute Assessment

Table 7. Livestock Feed Items for Acute Analysis for Beef Cattle, Poultry, and Swine

Commodity Recommended/

Established Tolerance (ppm)

Anticipated Residue (ppm)

1

Alfalfa, meal2--

4

0.25

Barley, grain30.05 0.01

Barley, hay29.0 3.7

Cotton, gin byproducts27.0 6.4

Cotton, meal3--

5

0.10

Cotton, undelinted seed31.5 0.30

Sorghum, grain, grain30.2 0.028

1 In an acute analysis for beef cattle, poultry, and swine, average field trial residues can be used for blended 

commodities and the highest average field trial (HAFT) values can be used for partially blended and nonblended 

commodities (Dietary Exposure Science Advisory Council, September 2009, Dietary Exposure Analysis).

2

Partially blended (Stasikowski, M., 8/20/99, Classification of Food Forms with Respect to Level of Blending. HED 

Standard Operating Procedure 99.6)

3 Blended (SOP 99.6)

4/Alfalfa meal is included in the livestock diet using the alfalfa hay tolerance (OPPTS 860.1000). The alfalfa hay 

tolerance is 0.5 ppm. 

5The cotton, undelinted seed tolerance is 1.5 ppm and is adequate to cover residues in cotton meal.
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Table 8. Bromoxynil Dietary Contributions for Acute Assessment for Beef Cattle, Poultry, and Swine Using Average 

Field Trial Residues for Blended Commodities and the Highest Average Field Trial (HAFT) Values for Partially 

Blended and Nonblended Commodities

% Diet b Dietary Contributions (ppm)

Feedstuff Type AR, ppm1 % Dry 

Matter Beef Poultry Swine Beef Poultry Swine 

Barley, hay R 3.7 88 10 -- -- 0.42 -- --

Cotton, gin 

byproducts R 6.4 90 5--

-- -- 0.36 -- --

Grain sorghum, grain CC 0.028 86 40 75 80 0.013 0.021 0.022

Barley grain CC 0.01 88 40 -- 5 0.0045 -- 0.0005

Cotton, undelinted 

seed

PC 0.30 88 Nu Nu Nu -- -- --

Cotton meal PC 0.10 89 5 20 15 0.0056 0.02 0.015

Alfalfa meal PC 0.25 89 Nu 5 -- -- 0.012 --

Totals 100 100 100 0.80 0.053 0.038

Table 9. Livestock Feed Items for Acute Assessment for Dairy Cattle

Commodity Recommended/

Established Tolerance (ppm)

Anticipated Residue 

(ppm)1

Alfalfa, meal --

2

0.13

Barley, grain 0.05 0.01

Barley, hay 9.0 0.43

Cotton, gin byproducts 7.0 3.2

Cotton, meal --

3

0.10

Cotton, undelinted seed 1.5 0.30

Sorghum, grain, grain 0.2 0.028

1 In an acute analysis for dairy cattle, tolerance level residues may be replaced with average field trial residues for 

blended, nonblended, and partially blended feed items commodities (Dietary Exposure Science Advisory Council, 

September 2009, Dietary Exposure Analysis).

2/Alfalfa meal is included in the livestock diet using the alfalfa hay tolerance (OPPTS 860.1000). The alfalfa hay 

tolerance is 0.5 ppm. 

3The cotton, undelinted seed tolerance is 1.5 ppm and is adequate to cover residues in cotton meal.
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Table 10. Bromoxynil Dietary Contributions for Acute Assessment for Dairy Cattle using Average 

Field Trial Residues for Blended, Nonblended, and Partially Blended Commodities

% Diet b Dietary Contributions (ppm)

Feedstuff Type AR, ppm1 % Dry 

Matter Dairy Diary 

Barley, hay R 0.43 88 45 0.22

Cotton, gin byproducts R 3.2 90 -- --

Grain sorghum, grain CC 0.028 86 45 0.015

Barley grain CC 0.01 88 -- --

Cotton, undelinted seed PC 0.30 88 10 0.034

Cotton meal PC 0.10 89 -- --

Alfalfa meal PC 0.13 89 -- --

Totals 100 0.269

Anticipated Residues in Meat and Milk for Use in DEEM

Chronic Anticipated Residues

Table 11. Transfer Coefficients and Chronic Anticipated Residues of Bromoxynil in Dairy Cattle 

Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)2

Milk 4.2 0.05 0.012 0.045 0.00054

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

Table 12. Transfer Coefficients and Chronic Anticipated Residues of Bromoxynil in Beef Cattle 

Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)2

Fat 4.2 0.68 0.16 0.015 0.0024

Kidney 2.26 0.54 0.0081

Liver 1.97 0.47 0.0070

Muscle 0.37 0.088 0.0013

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

Table 13. Transfer Coefficients and Chronic Anticipated Residues of Bromoxynil in Poultry Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)3

Eggs 0.70 <0.0520.071 0.0011 0.000078

Skin/Fat 0.70 0.08 0.11 0.00013

Liver 0.07 0.063 0.90 0.00099

Muscle 0.70 0.05 0.071 0.000078

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Residues in eggs were <0.05 ppm at the highest feeding level (1.0 ppm).

3 Obtained by multiplying the transfer coefficient by the calculated dietary burden.
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Table 14. Transfer Coefficients and Chronic Anticipated Residues of Bromoxynil in Swine Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)2

Fat 4.2 0.68 0.16 0.00094 0.00015

Kidney 2.26 0.54 0.00051

Liver 1.97 0.47 0.00044

Muscle 0.37 0.088 0.000083

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

Acute Anticipated Residues

Table 15. Transfer Coefficients and Acute Anticipated Residues of Bromoxynil in Dairy Cattle (Milk) 

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)2

Milk 4.2 0.05 0.012 0.269 0.0032

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

Table 16. Transfer Coefficients and Acute Anticipated Residues of Bromoxynil in Beef Cattle Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)2

Fat 4.2 0.68 0.16 0.80 0.13

Kidney 2.26 0.54 0.43

Liver 1.97 0.47 0.38

Muscle 0.37 0.088 0.070

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

Table 17. Transfer Coefficients and Acute Anticipated Residues of Bromoxynil in Poultry Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)3

Eggs 0.70 <0.0520.071 0.053 0.0038

Skin/Fat 0.70 0.08 0.11 0.0061

Liver 0.07 0.063 0.90 0.048

Muscle 0.70 0.05 0.071 0.0038

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2

 Residues in eggs were <0.05 ppm at the highest feeding level (1.0 ppm).

3 Obtained by multiplying the transfer coefficient by the calculated dietary burden.

Table 18. Transfer Coefficients and Acute Anticipated Residues of Bromoxynil in Swine Commodities

Matrix Feeding Level

(ppm)

Maximum Residues

at Feeding Level 

(ppm)

Transfer

Coefficient 1

Calculated Dietary 

Burden (ppm)

Calculated 

Anticipated 

Residues (ppm)2

Fat 4.2 0.68 0.16 0.038 0.0062

Kidney 2.26 0.54 0.020

Liver 1.97 0.47 0.018

Muscle 0.37 0.088 0.0033

1 Obtained by dividing the maximum residues at the feeding level by the feeding level.

2 Obtained by multiplying the transfer coefficient by the calculated dietary burden.