UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

MEMORANDUM 

Date: 09/ 17/2015 

Subject: Pronamide (Propyzamide). Summary of Analytical Chemistry and Residue Data to 

Support Registration Review. 

From: 

PC Code: 10170 1 

Decision No.: 476677 

Petition No.: NA 

Risk Assessment Type: NA 

TXR No.: NA 

MRlD No.: See Below 

DP Barcode: D42708 I and 04279 14 

Registration No.: NA 

Regulatory Action: Registration Review 

Case No.: 4092 

CAS No.: 23950-58-5 

40 CFR: 180.317 

ldeliz Negr6n-Encarnaci6n, Ph.D., Chemist ~0 ~~ 

Risk Assessment Branch V 

Health Effects Division (HED; 7509P) 

Through: Danett

Risk Assess

e Drew, 

ment 

Se

Bran

nior C

ch 

hemist 

V (HED; 7509P

~-~ 

) 

and 

Thomas Bloem, m~ ~~ 

Elizabeth Holman, Ph.D., Chemist ~ft"- »-lScience Advisory Council for Chemistry (ChemSAC) 

HED (7509P) 

To: Kevin Costello, Risk Manager 

Product Re-registration Division (7505P) 

Summary of Submitted Residue Chemistry Studies 

OCSPP 860 MRID Number Title 

Series Guideline 

860. 1340 46413406 Recd, R. (2002) Independent Laboratory Val idation of Dow AgroScicnces LLC Method 

GRM 02.21 - Determination of Residues of Propyzamide in Animal Tissues by Gas 

Chromatography with Negative-Ion Chemical Ionization Mass Spectrometry. 

860.1380 49654401 I luang. R.: Fleming. C. (2005) Waiver Request for a r:rozen Storage Stability Study on 

Mc1abolites of Pronamide. 

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Table of Contents 

1.0 Executive Sum1nary ............................................ .... .... ........ ........ .............................. ....... ... 3 

2.0 Regulatory Recommendations ............................................................................................ 4 

2.1 Data Deficiencies/Data Needs ......................... ........ .... .... ................................................. 4 

2.2 Tolerance Considerations ................................................................................................. 5 

2.2.1 Enforcement Analytical Method ............................................................................... 5 

2.2.2 Recommended Tolerances ........................................................................................ 5 

2.2.4 International Harmonization .................................... ...................................... ........... 7 

3.0 Introduction ................ ... .... ............ ............ ........ ............ .... .... .... ........................ ....... ... ........ 8 

3. 1 Chemical Identity .............................................. ..... .... .... ...................................... ............ g 

3.2 Physical/Chemical Characteristics ................................................................................... 8 

3.3 Pesticide Use Pattern/Directions for Use (860.1200) ....................................................... 9 

4.0 Metabolite/Degradate Residue Profile .............................................................................. I 0 

5.0 Residue Profile .................................................................................................................. 11 

5. 1 Residue Analytical Methods (860.1340) .... .... ................................................... ............. 11 

5.1. 1 Multi-Residue Methods (860. 1360) ........................................................................ 11 

5.1.2 Tolerance Enforcement Methods ............................................................................ 11 

5.1.4 Submittal of Analytical Reference Standards (860.1650) ...................................... 13 

5.2 Storage Stability (860.1380) .......................................................................................... 13 

5.3 Residue Data .................................................................................................................. 15 

5.3 .1 Crop Field Trials (860.1500) .................................................................................. 15 

5.3 .2 Field Rotational Crops (860.1900) .............................................. .................... ....... 16 

5.3.3 Processed Food and Feed (860.1520) ........................................................... .......... 16 

5.3.4 Meat, Milk, Poultry and Eggs (860.1480) ............ .................................................. 16 

5.3.4.1 Dietary Burden .... ............................................................................................ 16 

5.3.5. Food Handling (860.1460) ...................................................................................... 17 

5.3.6 Water, Fish, and Irrigated Crops (860.1 400) .......................................................... 17 

5.4 Food Residue Profile .................... .... .......................................................... ... .... ... .......... 18 

Appendix A. International Residue Limits Table ........................................................................ 19 

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1.0 Executive Summary 

This residue chemistry chapter was prepared to support registration review of pronamide, and 

reflect changes in the residue chemistry database since the 2009 scoping docwnent. Pronamide, 

also called propyzamide, [3,5-dichloro-N-( I, I -dimethyl-2-propynyl)benzamide] is a selective, 

systemic, pre-and post-emergence herbicide registered for the control of grasses and broadleaf 

weeds. It is a soil active systemic herbicide with uptake by susceptible weeds occurring through 

the roots. The qualitative nature of the residue in primary crops (i.e. alfalfa and lettuce) as well 

as rotational crops is understood. The terminal residues of concern in plants and livestock 

commodities, and in drinking water, are pronamide and its metabolites containing the 3,5-

dichlorobenzoyl moiety. Tolerances are established in 40 CFR §180.3 17 (a), (c) and (d) for the 

combined residues of propyzamide and its metabolites containing the 3,5-dichlorobenzoyl 

moiety (calculated in parent equivalents). Pronamide tolerances listed in section (a) range from 

0.02 ppm for certain livestock commodities to 10.0 ppm for non-grass animal feeds group 18 and 

alfalfa seed. Regional tolerances are listed in section (c) for pronamide on field pea seed (0.05 

ppm) and rhubarb (0. 1 ppm). Tolerances are listed in section (d) for inadvertent residues of 

pronamide on cereal grain forage, hay and straw, group 16. Adequate enforcement methods are 

available for the determination of residues in/on plant and livestock commodities. 

The HED scoping document for pronamide registration review includes a summary of the 

deficiencies of the residue chemistry database (0. Drew, 0 363904, 06/17/2009). The data 

deficiencies that were identified included the following: (1) Additional residue data for dried 

winter peas, and the vines and hay of winter peas were required. A magnitude of residue study 

has since been submitted and reviewed (MRID 46376601 ). (2) Removal of a tolerance for leaf 

lettuce was required. (3) Further optimize/improve the revised livestock enforcement method 

(TR 34-91-68) to yield acceptable recoveries at a fortification level equal to established livestock 

tolerances, and to submit bridging independent laboratory validation data. A livestock analytical 

method study was submitted (MRID 46413406) and forwarded to EPA's Analytical Chemistry 

Branch on 6118/07 for a Tolerance Method Validation (TMV). (4) Additional confirmatory 

storage stability data for the regulated pronamide metabolites on alfalfa, apples, grapes, lettuce, 

and peaches or plums were required but have not yet been submitted. 

Interregional Research Project No. 4 has submitted crop field trial data for winter peas (I. 

Negr6n-Encarnaci6n, 0383372, 09/17/2015). The submitted magnitude of the residue data are 

inadequate to satisfy data requirements because of insufficient number of trials. Although 

inadequate, the results of the pea field trials indicate that the maximum residues of pronamide 

convertible to 3,5-dichlorobenzoate were 0.98 ppm in/on fresh pea vines, 2.40 ppm in/on dry pea 

hay, and 0.08 ppm in/on dry peas following a single broadcast foliar application of pronamide at 

1.48 lb ai/A (lx). Because residues are above the tolerance currently established for field pea 

seed (0.05 ppm) it is recommended to establish an interim tolerance of 0. 10 ppm. Moreover, 

tolerances are not established for pea vines and dry pea hay because a feeding/grazing restriction 

is currently included in the labels. This restriction is impractical and unenforceable and may be 

removed from the labels. Interim tolerances of 1.5 ppm and 3.0 ppm are recommended for pea 

vines and dry pea hay, respectively. 

The tolerance for leaf lettuce was removed from the 40 CFR 180.317 and the use was removed 

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from the labels. However, magnitude of residue studies were submitted by Dow Agrosciences 

and the IR-4 project to re-establish a tolerance for leaf lettuce (I. Negr6n-Encarnaci6n, D424598, 

01 / 15/2015). A tolerance of2 ppm was recommended provided that the label was modified to 

add additional instructions for split applications. 

Dow AgroSciences submitted an Independent Laboratory Validation (ILV) study in support of 

the livestock commodity enforcement analytical method (MRID 46413406). This GC/MS 

method (Method ORM 02.21) has been adequately validated by the petitioner and has undergone 

successful IL V (W. Donovan, D3 l 2924, 06/ 18/2007). 

Storage stability data were required for the metabolites of pronamide on milk, lettuce, apples, 

plums, grapes and alfaJfa. A waiver request for the storage stability study was submitted by the 

registrant. HED recommends waiving the requirement for additional confirmatory storage 

stability data for the regulated pronamide metabolites on alfalfa, apples, grapes, lettuce, and 

peaches or plums, winter pea and milk. Based on the metabolism studies with lettuce and alfalfa, 

and with ruminants the main metabolites of pronamide contain the 3,5-dichlorobenzoyl moiety 

and are expected to be converted to methyl-3,5-dichlorobenzoate by the current enforcement 

methods. If degradates of these metabolites are formed in frozen storage conditions, it is likely 

that these are converted to the common moiety by the enforcement method. 

A reassessment of the dietary burden was performed to consider residues in pea feedstuff 

commodities, include maximum residues instead of tolerance level residues, and to use the most 

current version of Table l (OPPTS Test Guidelines 860.1000) released in June 2008. The reestimated dietary burdens are lower or similar to those used to establish the tolerances in 

livestock commodities; therefore, the current tolerances are adequate to cover potential residues 

of pronamide in these. 

2.0 Regulatory Recommendations 

The chemistry database of pronamide is adequate to support re-registration provided that the data 

needs (Section 2.1 ), and recommended tolerances (Section 2.2) and label modifications (Section 

2.2.2) are considered. Similarly, the new use in leaf lettuce is supported provided that tolerance 

recommendations and label amendments are followed. 

The standards of pronamide and methyl 3,5-dichlorobenzoate will expire in September 2015. In 

addition, the standard of 3,5-dichlorobenzoic acid is needed to support the new enforcement 

method for livestock commodities. The registrant should submit these standards to the EPA 

National Pesticide Standards Repository as detailed in section 5.1.4. 

2.1 Data Deficiencies/Data Needs 

The submitted field trial data for field pea commodities are inadequate (I. Negr6n-Encarnaci6n, 

D383372, 09/ 17/2015). Field trial data from two additional field trials for pea vines and hay and 

four additional field trials for pea seed are required. Storage stability data will be required if 

samples to be collected from the requested field pea field trials are stored frozen for a period 

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longer than three years. 

2.2 Tolerance Considerations 

2.2.1 Enforcement Analytical Method 

Residue Chemistry Chapter for TRED (J. Morales, 28-FEB-2002; 0 275536) 

Plant: An adequate residue analytical method is available for tolerance enforcement of residues 

in/on plant commodities. The PAM II lists a GLC/ECD method, designated as Method I, which 

conve11s residues of pronamide and its metabolites to methyl 3,5-dichlorobenzoate (MDCB). 

Method I was successfully radiovalidated using aged samples from the alfalfa and lettuce 

metabolism studies. 

Livestock: The 4/16/93 Residue Chapter reported that a revised version of the existing livestock 

enforcement method (Method I in PAM Volume 11), was submitted and resulted in increased 

method efficiency. Several modifications and an IL V were required and submitted by the 

registrant. Currently, an ILY of a gas chromatography method with negative-ion chemical 

ionization mass spectrometry detection (GC/MS), Method GRM 02.21 , for the determination of 

residues of pronamide and metabolites containing the 3,5-dichlorobenzoyl moiety as 3,5-

dichJorobenzoic acid (3,5-DCBA) in milk, bovine liver, kidney, muscle, and fat, and eggs and 

poultry muscle and fat is available. In general, recoveries were within the acceptable range of 

70-120%, and fortification levels (0.01 , 0.05, 0.25, and 0.50 ppm) bracketed the established 

tolerances for livestock commodities. The limit of quantitation (LOQ) was 0.0 I ppm. The 

reported limit of detection was 0.003 ppm. This method is considered adequate to enforce 

tolerances for residues of pronamide in/on livestock commodities. 

2.2.2 Recommended Tolerances 

The current tolerance expression for pronamide ( 40CFR § 180.317) is adequate for plant 

commodities, and includes both coverage and compliance statements for enforcement purposes. 

Recently, a tolerance of2 ppm has been recommended in support of a petition for the use of 

pronamide on leaf lettuce (I. Negron-Encarnacion, 0424598, 09/ 17/2015). Moreover, based on 

limited field trial data to support the use of pronamide on field pea, HED recommends increasing 

the tolerance for field pea seed from 0.05 ppm to 0.10 ppm, and establishing tolerances of 1.5 

ppm and 3.0 ppm for field pea vines and dry pea hay, respectively (I. Negron-Encarnacion, 

0 3833 72, 0911712015). 

The current tolerance expression is not adequate to enforce tolerances in livestock commodities 

as the tolerance enforcement method converts residues of pronamide to 3,5-dichlorobenzoic acid 

instead of methyl-3 ,5-dichlorobenzoate. Based on this, HED recommends to modify the 40 CfR 

§ 180.317 (a) General in two sections, (1) and (2). The first section may include the current 

tolerance expression for plants followed by a table with the tolerances for plant commodities 

while the second section may contain the tolerance expression below followed with a table with 

the tolerances for livestock commodities. 

The recommended tolerance expression for section (2) is: "Tolerances are established for 

residues of the herbicide propyzamide, including its metabolites and degradates, in or on the 

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commodities in the following table. Compliance with the tolerance levels specified in the table 

below is to be determined by measuring only those propyzamide residues convertible to 3,5-

dichlorobenzoic acid, expressed as the stoichiometric equivalent of propyzamide, 3,5-dichloroN-(1 , 1-dimethyl-2-propynyl)benzamide, in or on the commodity." 

Table 2.2.2. Tolerance Reassessment Summary for Pronamide 

Commodity Established I Proposed* Recommended Comments; Correct Commodity 

Tolerance (ppm) Tolerance (ppm) Definition 

Tolerance to be Listed Under 40 CFR §I 80.3 I 7(a)(l) 

Alfa lfa, seed 10.0 10.0 

Animal feed, nongrass, 10.0 10.0 

group 18 

Apple 0. 1 0.1 

Artichoke, globe 0.01 0.0 1 

Blackberry 0.05 0.05 

Blueberry 0.05 0.05 

Boysenberry 0.05 0.05 

Endive 1.0 1.0 

Fruit, stone, group 12 0.1 0.1 

Grape 0. 1 0. 1 

Lettuce, head 1.0 1.0 

Lettuce, leaf 1.0* 2.0 

Pear 0.1 0.1 

Radicchio 2.0 2.0 

Raspberry 0.05 0.05 

Tolerance to be Listed Under 40 CFR § 180.3 17(a)(2) 

Cattle, fat 0.2 0.2 

Cattle, kidney 0.4 0.4 

Cattle, liver 0.4 0.4 

Cattle, meat 0.02 0.02 

Cattle, meat byproducts, 0.02 0.02 

except kidney and liver 

Egg 0.02 0.02 

Goat, fat 0.2 0.2 

Goat, kidney 0.4 0.4 

Goat, liver 0.4 0.4 

Goat, meat 0.02 0.02 

Goat, meat byproducts, 0.02 0.02 

except kidney and liver 

Hog, fat 0.2 0.2 

Hog, kidney 0.4 0.4 

Hog, liver 0.4 0.4 

Hog, meat 0.02 0.02 

Hog, meat byproducts, 0.02 0.02 

except kidney and liver 

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Horse, fat 0.2 0.2 

Horse, kidney 0.4 0.4 

Horse, liver 0.4 0.4 

Horse, meat 0.02 0.02 

Horse, meat byproducts, 0.02 0.02 

except kidney and liver 

Milk 0.02 0.02 

Poultry, fat 0.02 0.02 

Poultry, liver 0.2 0.2 

Poultry, meat 0.02 0.02 

Poultry, meat byproducts, 0.02 0.02 

except liver 

Sheep, fat 0.2 0.2 

Sheep. kidney 0.4 0.4 

Sheep, liver 0.4 0.4 

Sheep, meat 0.02 0.02 

Sheep, meat byproducts, 0.02 0.02 

except kidney and liver 

Tolerance Listed Under 40 CFR §I 80.3 I 7(c) 

Pea, field, seed 0.05 0.101 

Tolerances To Be Listed Under 40 CFR § I 80.3 I 7(c) 

Pea, field, hay -- 3.01 

Pea, field, vines -- 1.5' 

1 To be re-evaluated upon submission of adequate magnitude of residue studies. 

2.2.4 International Harmonization 

Where possible, EPA encourages the harmonization of the US Tolerances and Maximum 

Residue Limits (MRLs) in key export markets. A tabl e with the US tolerances, and the Canadian 

and Codex MRLs for pronamide is provided in Appendix A. Currently, Mexican or Codex 

MRLs for pronamide have not been established. The US and Canadian tolerance expressions are 

harmonized for measurement of pronamide, including metabolites containing the 3,5-

dichlorobenzoate moiety. The Canadian MRLs for apple, blueberry and pear are harmonized 

with the US tolerances. The Canadian MRL for lettuce is 1 ppm while the recommended US 

tolerance is 2 ppm. The proposed use pattern do not support harmonized tolerance levels. An 

alternative use pattern that supports harmonization was recommended, refer to Section 6.0 of 

0424598. 

2.3 Label Recommendations 

The current labels for pronamide include plant back intervals for other crops than those 

recommended in the 2002 TRED. Rotation to other crops than leafy vegetables crop group 4, 

root and tuber vegetables crop group 1, and cereal grains is allowed by following a 365-day PBI. 

Feeding/grazing restrictions on the labels can be removed as potential residues of pronamide 

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in/on field pea feedstuff and livestock commodities have been evaluated, and these restrictions 

are generally considered impractical and/or unenforceable. 

For the new use on leaf lettuce, it is recommended that detailed instructions for split applications 

are included in the supplemental label, i.e. part of the maximum allowable application rate can be 

initially applied and the balance of the maximum allowable application rate can be made up to 10 

days later, and the maximum allowable total rates and corresponding PHis for split applications 

should follow the recommendations for regular applications. 

HED recommended a tolerance of2 ppm to support the proposed use pattern on leaf lettuce; 

however, an alternative use pattern that supports the tolerance proposed by the registrant (1 ppm) 

was recommended as well. If this alternative use pattern is desired, the label needs to be 

modified accordingly. 

3.0 Introduction 

Pronamide (also referred to as propyzamide) is a selective, systemic, pre-and post-emergence 

herbicide registered for the control of grasses and broadleaf weeds in several food and feed crops 

as well as woody ornamentals, Christmas trees, nursery stocks, lawns, turf, and fallow land. 

Pronamide is also known by the trade name Kerb®. 

3.1 Chemical Identity 

Table 3.1 Pronamide Nomenclature. 

Compound 0 

Cl 

I 

~ 

H 

N~ CH3 ~CH 

~ 

Cl 

Common name Pronamide or Pronamide 

Company experimental name Not applicable 

IUPAC name 3,5-dichloro-N-(1 , 1-dimethylpropynyl)benzamide 

CAS name 3,5-dichloro-N-( I, l-dimethyl-2-propynyl)benzamide 

CAS registry number 23950-58-5 

End-use product (EP) 50% WP formulation (Kerb® 50-W Herbicide; EPA Reg. No. 62719-397) 

3.2 Physical/Chemical Characteristics 

Propyzamide is readily soluble in water and is not expected to volatilize significantly due to the 

compound's relatively low vapor pressure of 8.5 x 10-5 torr. The physicochemical properties of 

pronamide are in Table 3.2. 

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Table 3.2. Physicochcmical Properties of Pronamide. 

Parameter Value Reference 

Melting range 155-156°C Pronamide TRED; J. 

Morales. 28-FEB-2002; 

DP#: 275536 

Water solubility 15 mg/L at 25°C Pronamide TRED; J. 

Solvent solubility Dimethyl sulfoxide and dimethyl Morales, 28-FEB-2002; 

formarnide at 33 mg/L; DP#: 275536 

Mesityl oxide, isophorone, methyl ethyl 

ketone, and cyclohexanone at 20 mg/L; 

Methanol, isopropanol, and 

chlorobenzene at I 2- I 5 mg/L; 

Butyl cellosolve, xylene, acetonitrile, 

and kerosene at I 0 mg/L; 

Nitrobenzene and ethylene dichloride at 

5 mg/L 

Vapor pressure 8.50 x I 0·

5 torr at 25°C 

Octanol/water partition coefficient, 3.05-3.27 Pronarnide TRED; J. 

Log( Po\\') Morales. 28-FEB-2002; 

DP#: 275536 

3.3 Pesticide Use Pattern/Directions for Use (860.1200) 

There are two end-use product labels registered with pronamide as the active ingredient. These 

include liquid, and wettable powder formulations. Pronamide, also known by the trade name 

Kerb®, may be applied using ground spray equipment, by soil incorporation, or by aircraft. The 

single application rates for agricultural uses range from 0.5 to 4 lb ail A, and the maximum 

application rate per year range from 1 to 6 lbs ai/A. The 0212812002 Residue Chemistry Chapter 

recommended plant back intervals of 30-day for leafy vegetables (except Brassica vegetables) 

(Crop Group 4); 90-day for root and tuber vegetables (Crop Group 1 ); 360-day for cereal grains 

(Crop Group 15) and the forage, fodder, and straw of cereal grains (Crop Group 16). Currently, 

extensive rotational crop restrictions, dependent on application rates, are currently established on 

the product labels. The restrictions for root and tuber vegetables, leafy vegetables crop group 4, 

and cereal grains are considered adequate. However, restrictions for other crops such as legume 

vegetables and cotton (90 to 150-day PBl), and brassica leafy vegetables, cucurbit vegetables, 

fruiting vegetables, and bulb vegetables (90 to 2 10-day PB ls) are included in the labels. As 

indicated in the 2002 TRED, these rotational crop restrictions are inappropriate based on the 

results of the reviewed confined and limited rotational field studies. 

Conclusions: Appropriate plant back intervals are established for leafy vegetables crop group 4, 

root and tuber vegetables crop group 1, and cereal grains in the labels of Kerb® (EPA Reg. Nos. 

62719-578, and 627 19-397) and those from Willowood (EPA Reg. Nos. 87290-22, 87290-9 and 

87290-3). However, rotation to other crops than those was not recommended in the 2002 TRED. 

Rotation to other crops is allowed by following a 365-day PBI. The special local need label 

(EPA Reg. No. 627 19-578) specifies single and maximum application rates of 4 lbs ail A and 6 

lbs ail A/year, respectively, for head lettuce. This is not supported by the limited rotational crop 

study which was conducted at a maximum application rate of 2 lbs ail A. However, the label 

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specifies that crops other than lettuce should not be planted back for a period of 12 months 

following application. 

The use on leaf lettuce has been removed from the label according to previous recommendations; 

however, a new use on leaf lettuce has been proposed. Other label modifications have been 

recommended to support petitions for use of pronamide on leaf lettuce and field pea; refer to 

D424598 and 0383372, respectively, for detailed information. These are: (1) For the new use 

on leaf lettuce, it is recommended that detailed instructions for split applications are included in 

the supplemental label, e.g. for split applications part of the maximum allowable application rate 

can be initially applied and the balance of the maximum allowable application rate can be made 

up to 10 days later. The maximum allowable total rates and corresponding PHis for split 

applications for leaflettuce should be 0.5, 0.75, 1.5, and 2.0 lbs ai/A with corresponding PHis of 

25, 35, 45, and 55 days, respectively. (2) For the established use on field pea, the registrant may 

delete the existing feeding/grazing restrictions on the label since they are impractical and/or 

unenforceable. 

4.0 Metabolite/Degradate Residue Profile 

Residue Chemistry Chapter for TRED (J. Morales, 02/28/2002; 0275536) 

Primmy Crops: The qualitative nature of the residue in plants is adequately understood on 

alfalfa, lettuce and similar crops. The 4/ 1611993 Residue Chapter reported that studies with 

alfalfa and lettuce indicate that pronamide is readily absorbed by plants through the root system, 

translocated upward, and distributed into the entire plant. The degree of translocation from leaf 

absorption is not appreciable. The terminal residues in alfalfa and lettuce consist mainly of the 

parent compound pronamide (N-(1, l-dimethylpropynyl)-3,5-dichlorobenzamide), glucose 

conjugates, and glucose-malonyl conjugates of pronamide, all containing the 3,5-

dichlorobenzene moiety. Metabolism primarily occurs via conjugation to (malonyl) glucose. No 

evidence of fragmentation or loss of the chloro substituent of the aromatic ring was observed. 

The terminal residues of concern are pronamide and its metabolites containing the 3,5-

dichlorobenzoyl moiety. 

Rotational Crops: The qualitative nature of the residue in rotational crops is adequately 

understood based on an acceptable confined rotational crop study (MRID 41462001 and 

41913506). In this study, uniformly ring labeled [14

C]pronamide was applied at a rate of4.0 lb 

ai/A to bare ground plots, and crops were planted in the treated areas after 30 days, 6 months, 

and 1 year. The subplots representing each plantback interval (PBI) were allowed to remain 

fallow until such time that lettuce (a leafy vegetable), carrots (a root crop), and wheat (a small 

grain) were planted. The terminal residues of concern in rotated crops following treatment of 

primary crops with pronamide consist of the parent pronamide and its metabolites bearing the 

3,5-dichlorobenzoyl moiety. 

Livestock: The qualitative nature of the residue in livestock is adequately understood. The 

4/ 16/93 Residue Chapter reported studies involving lactating goats and laying hens indicate that 

the primary route of elimination is by excretion (urine and feces). Minimal residues were 

distributed to goat and poultry muscle. The major metabolites in the eggs, liver, and fat of 

poultry are pronamide and 3,5 dichlorobenzoic acid. The major metabolites in the milk, fat, 

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muscle, and liver of goats are pronamide, 3,5-dichlorobenzoic acid, and compounds containing 

the 3,5-dichlorobenzoyl moiety. The metabolic pathway involves modification of the aliphatic 

portion of pronamide. The terminal residues of concern in livestock commodities are pronarnide 

and its metabolites containing the 3,5-dichlorobenzoyl moiety. 

The residues of concern for pronamide are depicted in Table 4.3. 

Table 4.3. Summary of Pronamide Metabolites and Degradates to be included in the Risk Assessment and 

Tolerance Expression 

Matrix Residues included in Risk Residues included in 

Assessment Tolerance Exoression 

Plants Primary Crop 

Rotational Crop pronamide and its metabolites pronamide and its metabolites 

Livestock Ruminant containing the 3,5- containing the 3,5-

Poultry dichlorobenzoyl moiety dichlorobenzoyl moiety 

Drinking Water Not Aoolicable 

Conclusions. For purposes of registration review, no additional plant metabolism studies are 

required; however, because the available metabolism studies were only conducted on alfalfa and 

lettuce, HED may request additional metabolism studies in the future should the petitioner seek 

for additional uses on other crop groups. 

5.0 Residue Profile 

5.1 Residue Analytical Methods (860.1340) 

5.1.1 Multi-Residue Methods (860.1360) . 

Residue Chemistry Chapter for TRED (J. Morales, 02/28/2002; D275536) 

The 10/99 FDA PESTDATA (PAM Volume I, Appendix) indicates that pronamide is completely 

recovered (>80%) using MRMs PAM Volume I Sections 302 (Luke method; Protocol D) but is 

only partially recovered using Method 303 (Mills, Onley, and Gaither method; Protocol E). 

MRM testing data for pronamidc and a metabolite containing the 3,5-dichlorobenzoyl moiety are 

also available (MRID 43493203); these data have been forwarded to FDA for review (W. 

Donovan, 0340389, 06/06/2007). 

5.1.2 Tolerance Enforcement Methods 

Residue Chemistry Chapter for TRED (J. Morales, 02/28/2002; D275536) 

Plants: An adequate residue analytical method is available for tolerance enforcement. The 

PAM II lists a GLC/ECD method, designated as Method I, which converts residues of pronamide 

and its metabolites to MDCB. This method consists of hydrolysis of the parent compound and 

its metabolites by refluxing with methanol and sulfuric acid. The hydrolyzed products are 

methylated, and the methyl ester reaction product is steam distilled. The ester is extracted from 

the distillate with petroleum ether followed by an additional Florisil column clean up. Residue is 

determined by gas liquid chromatography using an electron capture detector. Two columns can 

be used; one may be used for confirmatory purposes. During Agency validation of this method 

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using lettuce as the substrate, recoveries were 80-85% at the 2-ppm fortification level, and 82.5-

92.5% at the 4-ppm level. The listed detection limit is 0.2 ppm for plant commodities. Method I 

was successfully radiovalidated using aged samples from the alfalfa and lettuce metabolism 

studies. 

Livestock: The 4116/93 Residue Chapter reported that a revised version of the existing livestock 

enforcement method (Method I in PAM Volume II based on GC/EC), which includes an alkaline 

hydrolysis to release bound residues, was submitted and resulted in increased method efficiency. 

The Chapter required an independent laboratory validation (lL V) of the revised method prior to 

method validation by the Agency. An ILV of a gas chromatography method with negative-ion 

chemical ionization mass spectrometry detection (GC/MS), Method ORM 02.21, for the 

determination of residues of pronamide and metabolites containing the 3,5-dichlorobenzoyl 

moiety as 3,5-dichlorobenzoic acid (3,5-DCBA) in poultry fat and bovine liver was submitted 

(MRJD 46413406). In addition to the ILY report, the submission included a complete method 

description of the original method, along with supporting method validation data for milk, 

bovine liver, kidney, muscle, and fat, and eggs and poultry muscle and fat. Fat samples were 

extracted with ethyl acetate and centrifuged. An aliquot of the extract was evaporated to 

dryness, redissolved in 1,4-dioxane, and hydrolyzed by adding 9 N sulfuric acid and heating at 

100 °C. Samples of milk, eggs, and tissues other than fat were extracted and hydrolyzed by 

adding 4 N sodium hydroxide and heating at 80 °C, followed by several steps including a second 

hydrolysis procedure. During hydrolysis, bound residues of propyzamide and metabolites were 

further solubilized and hydrolyzed to 3,5-dichlorobenzoyl acid. This method was forwarded to 

EPA's Analytical Chemistry Branch on 6/18/07 for a Tolerance Method Validation (TMY); 

however, current procedures do not require a TMV. The method was reviewed to determine if is 

appropriate as an enforcement method. The method as written was adequately validated and the 

sample analysis (excluding overnight incubation, and automated GC analysis) was conducted in 

less than 24 hours. In general, recoveries were within the acceptable range of 70-120%, and 

fortification levels (0.0 1, 0.05, 0.25, and 0.50 ppm) bracketed the established tolerances for 

livestock commodities. The limit of quantitation (LOQ, determined as the lowest limit of 

method validation; LLMV) was 0.01 ppm. The reported limit of detection was 0.003 ppm. The 

registrant indicated that confirmation is by comparison of the retention time (GC) as well as the 

peak area ratio resulting from selected ion monitoring following MS analysis in the negative 

chemical ioni zation mode. Additional confirmatory data wi ll not be required as Method I in 

PAM Volume II (based on GC/EC) may be used for confirmation. 

No radiovalidation data was provided. Part of the radioactivity in the hen metabolism study was 

liberated using acetonitrile or methanol (MRID 40782201). A second study was conducted to 

further characterize/identify the non-extractable residue. In this study, base hydrolysis was 

shown to release most of the residue in liver increasing from 48% using methanol and 

acetonitrile to 92% using base hydrolysis (MRJD 42614201 ). This study also indicates that the 

enforcement method by that time was modified to incorporate a base hydrolysis step, resulting in 

significant increase in recoveries, 40% to 66%, 59% to 74%, and 65% to 91 % for breast muscle, 

thigh muscle, and liver, respectively. 

Conclusions. Enforcement methods are available to enforce the tolerances of pronarnide on 

plants and livestock commodities. Because the enforcement method for livestock involves base 

Page 12 of20 
Pronamide Summary of Analytical Chemistry and Residue Data Barcode 0427081 

hydrolysis extraction and the results of the second metabolism study with hen which showed 

good recoveries when using base hydrolysis the radiovalidation of the enforcement method for 

livestock can be waived. 

5.1.4 Submittal of Analytical Reference Standards (860.1650) 

Reference standards for pronamide are currently available in the standard repository (personal 

communication with Gregory Verdin (05/ 11 /2015); however, the expiration dates are 09/22/2015 

for Pronamide and 09/30/2015 for methyl 3,5-dichlorobenzoate (MDCB). In addition, the 

standard of 3,5-dichlorobenzoic acid is needed to support the new enforcement method for 

livestock commodities. These standards should be sent to the Analytical Chemistry Branch in Ft. 

Meade who is the owner of this repository. The address to submit standards is: 

USEPA 

National Pesticide Standards Repository/Analytical Chemistry Branch/OPP 

70 I Mapes Road 

Fort George G. Meade, MD 20755-5350 

The full 9 digit zip code is mandatory or the mail will be returned to you. 

5.2 Storage Stability (860.1380) 

Residue Chemistry Chapter for TRED (J. Morales, 02/28/2002; 0275536) 

Waiver Request for Storage Stability Study (MRJD 4965440 I) 

Plants: The TRED of pronamide summarizes the results of a three-year storage stability study 

(MRID 4472270 I). The submitted data indicate that pronamide per se (the predominant residue 

identified in plant metabolism studies), as measured by a specific GC method for pronamide, is 

reasonably stable under frozen storage conditions for up to three years in/on alfalfa, apples, 

grapes, lettuce, and peaches (plum surrogate). Additional confirmatory storage stability data for 

the regulated pronamide metabolites on alfalfa, apples, grapes, lettuce, and peaches or plums was 

required. Limited storage stability data for pronamide is available in pea commodities. Storage 

stability data submitted in conjunction with pea field trial indicate that residues of pronamide are 

stable under frozen storage for up to 98 days for pea vines, 95 days for pea hay, and 84 days for 

pea seed which do not covers the storage duration of the crop field trial samples. 

Livestock: The 4/ 16/93 Residue Chapter reported that pronamide is stable in poultry eggs and 

tissues under frozen conditions for up to 34 months. For the purposes of reregistration, the 

Chapter concluded that the available stability data for poultry commodities may be translated to 

satisfy the storage stability data requirements for ruminant tissues. The Chapter, however, 

required additional storage stability data for milk. In the TRED, submitted data indicate that 

pronamide per se, as measured by a specific GC method for pronamide, is reasonably stable 

under frozen storage conditions for up to three years in milk. Samples of livestock commodities 

that were used for tolerance reassessment were stored frozen for interval of less than three years. 

However, analysis of metabolites containing the 3,5-dichlorobenzoyl moiety was not included in 

the study. Additional confirmatory storage stability data for the regulated pronamide metabolites 

on milk was required. This data has not yet been submitted. 

Page 13 of20 
Pronamide Summary of Analytical Chemistry and Residue Data Barcode 0427081 

Waiver request 

A waiver for the storage stability study for the metabolites of pronamide was requested (MRID 

49654401 ). As the registrant describes, the existing frozen storage stability data indicates the 

two key structural components of pronamide, the 3,5-dichlorobenzoyl moiety and the alkyl side 

chain, are stable in the presence of plant and milk matrices under frozen storage condition. In the 

plant and animal metabolism studies, pronamide was observed to be slowly metabolized through 

a series of simple oxidative reactions that take place on the alkyl side chain of the molecule. 

While the alkyl side chain is susceptible to metabolism via oxidation and sugar conjugation, 

metabolites showing degradation of the 3,5-dichlorobenzoyl moiety were not observed. 

Therefore, it is proposed to be structurally stable and resistant to metabolism in crop and animal 

tissues, i.e. cellular enzymes in living plant and animal tissues only affect the metabolism and 

transformation of the alkyl side chain, but not the stable 3,5-dichlorobenzoyl structure of 

pronamide and its metabolites. While data is not available to specifically address the storage 

stability of each individual pronamide metabolite or the relative stability of the various forms of 

the alkyl side chain of the metabolites under frozen storage condition, it is indicated that the 3,5-

dichlorobenzoyl moiety is stable. Because the enforcement analytical method measures all the 

residues convertible to the 3,5-dichlorobenzoyl moiety it is stated that the metabolites containing 

such moiety can be accurately determined regardless of the relative stability of the various alkyl 

side chains. 

Cl 0 H CH, 

0 11 I 

-C-N -~-C1CH 

Cl CH, 

ProMmlcle 

+ 

Cl O 0-A-R 

Cl 

m1tabollta 

<0nt1lnln13,S·dlchloroblnzoyl moiety 

Cl 0 0-!-R 

Cl 

~OJCHa Cl 0 CH10M Cl 0 M ell, 

V'i. CHa (\._.(.' )ai. o-~-~-~ -COOH ct CM, RH·Z'6M ,)---' "'w CM, Rff .. 25111 Cl CMi RH·l46SO 

Cl O H CM, Cl 0 H C.1 Cl 0 H r 0 11 1 0 . 1, 0 .1. 

-C-11-~-x °'• -c-· ~-~ CH,OH -c-•-' -x·COOH 

Cl CM, RH·245IO Cl CMo RH·21702 Ct at, Rlt-2760 

Cl 0 H l"'" Cpl 0 M Clfa Cl i M r;MtM O JI I Ill p 11! -C·ll· '-~ CH,OH -C-11-~ -CH,CH,OH - -11-lji-~~COON 

CH OH CH, CH, Cl 1 RH·2652l C RH·26J17 RH·27U4 

Cl y H CHa Clo ~ Cl 0 " CM, 

-c-~-~-cH,cooH - "°" /-\-~-~ -~-C•H,OH Cl ~... RH-26059 Cl OCBA ).J ~. RH·24"& Cl 

+ Supr conJupte of the mebbolltes 

Figure 5.2 Structure of pronamide and its metabolites containing the 3,5-dichlorobenzoyl moiety. Sugar 

conjugation occurs on the a lkyl side chain. Excerpt from registrant waiver request (MRID 49654401). 

Conclusions: HED recommends waiving the requirement for additional confirmatory storage 

stability data for the regulated pronamide metabolites on alfalfa, apples, grapes, lettuce, and 

peaches or plums, and milk. Based on the metabolism studies with lettuce and alfalfa the main 

metabolites of pronamide containing the 3,5-dichlorobenzoyl moiety are RH25891 (m-g), 

Page 14 of20 
Pronamide Summary of Analytical Chemistry and Residue Data Barcode 0427081 

RH26521 (m-g), RH26521 (g) and RH24848 (m-g), where m refers to malonyl and g to glucose 

conjugates. The main metabolites of pronamide on milk are compound I (RH-24644), II (RH24580), V (RH-26377), DCBA, X (unclear from best copy available), and XII (RH-27414). The 

structures of these metabolites are in Pronamide Response to Registration Standard (J.B. Stokes, 

08/16/1989) and in MRIDs 40494801 (goat), 40494802 (lettuce), and 40494803 (alfalfa). All 

these metabolites are expected to be converted to methyl-3,5-dichlorobenzoate by the current 

enforcement methods. Metabolism studies and the enforcement method sample preparation 

procedures suggest that the 3,5-dichlorobenzoyl moiety is quite stable to plant and animal 

enzymes, and to base and/or acid hydrolysis. If degradates of these metabolites are formed in 

frozen storage conditions, it is likely that these are converted to the common moiety by the 

enforcement method. 

5.3 Residue Data 

5.3.1 Crop Field Trials (860.1500) 

Field Pea 

Crop field trial data were required for field pea in the 2009 scoping document. These data were 

submitted by the IR-4 project. The residue chemistry memo summarizing the data and HED's 

recommendations is available as D383372 (I. Negron-Encarnacion, 09117/2015). In summary, 

the submitted magnitude of the residue data are inadequate to satisfy data requirements because 

of insufficient number of trials. A minimum of three trials is required for field pea forage and 

hay with Austrian Winter pea as the preferred cultivar; and field pea seeds are considered dried 

shelled peas and require a minimum of five trials. Furthermore, two independently composited 

samples of treated commodity should be collected and separately analyzed in each field trial. 

Although inadequate, the results of the pea field trials from the current submission indicate that 

the maximum residues of pronamide (expressed as pronamide + its metabolites containing the 

MDCB moiety) were 0.98 ppm in/on fresh pea vines, 2.40 ppm in/on dry pea hay, and 0.08 ppm 

in/on dry peas following a single broadcast foliar application of pronamide at 1.48 lb ail A (Ix). 

Because residues are above the tolerance currently established for field pea seed (0.05 ppm) it is 

recommended to establish an interim tolerance of 0. 10 ppm. Moreover, tolerances are not 

established for pea vines and dry pea hay because a restriction is currently included in the labels. 

This restriction is impractical and should be removed from the labels. An interim tolerance of 

1.5 ppm and 3.0 ppm is recommended for pea vines and dry pea hay, respectively. 

Leaf Lettuce 

As recommended by the 2009 scoping document, the tolerance for leaf lettuce was removed 

from the 40 CFR 180.317 and the use was removed from the labels. However, magnitude of 

residue studies were submitted by Dow Agrosciences and the IR-4 project to re-establish a 

tolerance for leaf lettuce (I. Negron-Encarnacion, D424598, 01115/2015). A tolerance of2 ppm 

was recommended provided that tolerance recommendations and label amendments are 

followed. 

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Pronamide Summary of Analytical Chemistry and Residue Data Barcode 042708 1 

5.3.2 Field Rotational Crops (860.1900) 

Residue Chemistry Chapter for TRED (J. Morales. 02/28/2002; 0275536) 

An acceptable limited field rotational crop study (MRID 44661501) with pronamide is available. 

Based on a re-evaluation of this study, the 02/28/2002 Residue Chemistry Chapter recommended 

plant back intervals of 30-day for leafy vegetables (except Brassica vegetables) (Crop Group 4); 

90-day for root and tuber vegetables (Crop Group l); 360-day for cereal grains (Crop Group 15) 

and the forage, fodder, and straw of cereal grains (Crop Group 16). These are based on limited 

field rotational crop studies performed after application of2 lbs ai/A of pronamide to bare soil 

and planting of lettuce, carrots, wheat and sorghum at plant back intervals of 30, 90, 180, and/or 

360 days. The current rotation restrictions are adequate. Rotation to other crops than leafy 

vegetables crop group 4, root and tuber vegetables crop group I, and cereal grains is allowed by 

following a 365-day PBI. 

5.3.3 Processed Food and Feed (860.1520) 

Residue Chemistry Chapter for TRED (J. Morales, 02/28/2002; 0275536) 

The requirement for data depicting magnitude of the residue in the processed commodities of 

apples, grapes, and plums is fulfilled . In 1995, HED waived the requirement to conduct 

processing studies for apples, grapes, and plums based on the results of field trials conducted at 

exaggerated rates equivalent to or greater than the maximum theoretical concentration factors 

from processing (S. Funk, 0 2 13037, 3/29/95). Field trials at exaggerated rates showed that 

residues in processed commodities would be anticipated to be < 0.1 ppm, the reassessed 

tolerances for the RACs. No other processing studies have been submitted or required. 

5.3.4 Meat, Milk, Poultry and Eggs (860.1480) 

Residue Chemistry Chapter for TRED (J. Morales. 02/28/2002; 0 275536) 

No additional data were required for residues of pronamide on meat, milk, poultry and eggs in 

the 2002 TRED. Tolerances for kidney and liver of cattle, goats, hogs, horses, and sheep were 

recommended to be increased to 0.4 ppm due to recent improvement in the efficiency of the 

revised enforcement method for goat liver and the levels of transfer found in the cattle feeding 

study. These tolerances are currently established in the 40 CFR 180.317. 

5.3.4.1 Dietary Burden 

The livestock dietary burden of pronamide was estimated in the 2002 TRED to consider 

reassessed tolerances for livestock feed items. The maximum theoretical dietary burdens of 

pronamide to beef cattle, dairy cattle, swine, and poultry were re-calculated to be 10. 7 ppm, l l.2 

ppm, 1.0 ppm, and 1.0 ppm, respectively. A reassessment of the dietary burden was performed 

to consider residues in pea feedstuff commodities, include maximum residues instead of 

tolerance level residues, and to use the most current version of Table 1 (OPPTS Test Guidelines 

860.1000) released in June 2008 (Table 5.3.4. 1). 

Page 16 of20 
Pronamide Summary of Analytical Chemistry and Residue Data 

Table 5.3.4. 1. Calculation of Dietary Burdens of Pronamide Residues to Livestock. 

% Dry Feedstuff Type' Matter2 %Diet2 

Beef Cattle (R = 15%; CC = 80%; PC= 5% ) 

Alfalfa, hay4 R 89 15 

TOTAL BURDEN --

Dairy Cattle (R = 45%; CC= 45%; PC= 10%) 

Alfalfa, hay4 R 89 5 

Alfalfa, forage4 R 35 20 

Alfalfa, silage4 R 40 20 

Alfalfa, meals PC 89 10 

TOT AL BURDEN --

Swine (CC= 85%; PC = 15%) 

Alfalfa, mea15 PC NA 5 

Pea, field, seed PC NA 10 

TOTAL BURDEN --

Poultry (CC = 75%; PC= 25%) 

Alfalfa, meals PC NA 5 

Pea, field, seed PC NA 20 

TOTAL BURDEN -- 1 R: Roughage; CC: Carbohydrate concentrate; PC: Protem concentrate. 2 Table I Feedstuffs (July 2008). 

HAFT 

(ppm) 

9.52 

9.52 

9.52 

9.52 

9.52 

9.52 

0.08 

9.52 

0.08 

Barcode D42708 l 

Dietary 

Contribution 

(ppm)3 

1.6 

1.6 

0.53 

5.4 

4.8 

I. I 

11.8 

0.476 

0.008 

0.484 

0.476 

0.0 16 

0.492 

3 Contribution =([tolerance /% DM] X % diet) for beef and dairy cattle; contribution = ([tolerance] X % diet) for 

poultry and swine. 4 Alfalfa hay, forage and silage belongs to the nongrass animal feeds group for which the highest residue observed 

that results from a use pattern similar to the labeled use pattern is 9.52 ppm (Pronamide Registration Standard, C. 

Trichilo, I I /03/ 1985). 

5 Data are not available (or required) for alfalfa meal; however, alfa lfa meal should be included in the diet. The 

tolerance for nongrass animal feeds (hay) is used for a lfalfa meal. 

Conclusion: The updated dietary burden is 1.6 ppm for beef cattle, 11.8 ppm for dairy cattle, 

0.484 ppm for swine, and 0.492 ppm for poultry. These values are significantly lower than the 

dietary burden previously calculated to establish the current tolerances in milk, meat poultry and 

eggs, i.e. 10.7, 1.0 and 1.0 for beef cattle, swine and poultry, respectively, and slightly higher to 

that of dairy cattle, 11.2 ppm. Based on the lower or similar re-calculated dietary burdens the 

current tolerances for pronamide in livestock commodities are considered adequate. 

5.3.5. Food Handling (860.1460) 

Pronamide is not registered for use in food-handling establishments; therefore, no residue 

chemistry data are required. 

5.3.6 Water, Fish, and Irrigated Crops (860.1400) 

Pronamide is not registered for aquatic uses; therefore, no residue chemistry data are required. 

Page 17of20 
Pronamide Summary of Analytical Chemistry and Residue Data Barcode 0427081 

5.4 Food Residue Profile 

Tolerances are established in the 40 CFR § 180.317 for the use of pronamide on alfalfa, apple, 

arti choke, berries, endive, stone fruits, grape, head lettuce, pear, radicchio, fie ld pea, and 

rhubarb. In addition, tolerances are established for livestock commodities, and several feed 

commodities. Generally, residues below 0.4 ppm are expected in most food commodities with 

the exception of head lettuce (1.0 ppm), endive ( 1.0 ppm) and radicchio (2.0 ppm). A tolerance 

of 2. 0 ppm was recommended to support a proposed new use on leaf lettuce. This tolerance is 

supported by adequate residue data. Interim tolerances of 0.10 ppm, 1.5 ppm and 3 .0 ppm are 

recommended for field pea seed, vines and hay, respectively. Additional crop field trial data is 

required to support the use on field pea. The livestock dietary burden was recalculated to 

determine if new tolerances for livestock commodities were needed. The non-grass animal feeds 

are the major contributors to the dietary burden, field pea feedstuff commodities being a minor 

contributor. Based on the lower or similar re-calculated dietary burdens the current tolerances 

for pronamide in livestock commodities are considered adequate. The current labels for 

pronamide include plant back intervals for other crops than those recommended in the 2002 

TRED. These PBls need to be removed. Rotation to other crops than leafy vegetables crop 

group 4, root and tuber vegetables crop group I , and cereal grains is allowed by following a 365-

day PBI. 

Page 18 of20 
Pronamide Summary of Analytical Chemistry and Residue Data Barcode 0427081 

Appendix A. International Residue Limits Table 

Pronamide (aka Propyzamide; PC Code 101701) 

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition: 

us Canada Mexico' Codex 

40 C FR 180.31 7: 3.5-dichloro-J\T-(I , 1- None 

(a) General. (I) propyzamide residues dimethy l-2-propyn- Iconvertible to methy l 3,5-dichlorobenzoate, yl)benzamide, including 

expressed as the stoichiometric equivalent of metabo lites containing 

propyzamide, 3,5-dichloro-N-( I, l-dimethyl-2- the 3,5-dich lorobenzoate 

propynyl)benzam ide mo iety 

Commodity 

Tolerance (pom) /Maximum Residue Limit (111}.{ k~ 

us Canada Mexico' Codex 

Alfalfa, seed 10.0 

Animal feed, nongrass, group 18 10.0 

Aoole 0.1 0.1 

Artichoke, globe 0.01 

Blackberry 0.05 

Blueberry 0.05 0.05 lowbush blueberries 

Boysenberry 0.05 

Cattle, fat 0.2 

Cattle, kidney 0.4 

Cattle, liver 0.4 

Cattle, meat 0.02 

Cattle, meat byproducts. except 0.02 

kidney and liver 

Egg 0.02 

Endive 1.0 

Fruit, stone, group 12 0.1 

Goat, fat 0.2 

Goat, kidney 0.4 

Goat, liver 0.4 

Goat, meat 0.02 

Goat, meat byproducts, except 0.02 

kidney and liver 

Grape 0.1 

Hog, fat 0.2 

I log, kidney 0.4 

Hog, liver 0.4 

Hog, meat 0.02 

Hog, meat byproducts, except 0.02 

kidney and liver 

Horse. fat 0.2 

Horse, kidney 0.4 

Horse, liver 0.4 

Horse, meat 0.02 

I lorse, meat byproducts, except 0.02 

kidney and li ver 

Lettuce, head 1.0 I lettuce 

Page 19 of20 
Pronamide Summary of Analytical Chemistry and Residue Data Barcode 0427081 

Summary of US and International Tolerances and Maximum Residue Limits 

Residue Definition: 

us Canada Mex ico' Codex 

Milk 0.02 

Pear 0. 1 0. 1 

Poultry, fat 0.02 

Poultry, liver 0.2 

Poultry, meat 0.02 

Poultry. meat byproducts, except 0.02 

liver 

Radicchio 2.0 

Raspberry 0.05 

Sheep, fat 0.2 

Sheep, kidney 0.4 

Sheep, liver 0.4 

Sheep, meat 0.02 

Sheep, meat byproducts, except 0.02 

kidney and liver 

Completed: M. Negussie; 05/07/15 

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

(c) Tolerances with regional registrations. Tolerances with regional registration, as defined in § 180. I (I), are 

established for residues of the herbicide propyzamide, including its metabolites and degradates, in or on the 

commodities in the table in this paragraph. Compliance with the tolerance levels specified in this paragraph is to be 

determined by measuring only those propyzamide residues convertible to methyl 3,5-dichlorobenzoate, expressed as 

the stoichiometric equivalent of propyzamide, 3,5-dichloro-N-( I, l-dimethyl-2-propynyl)benzamide, in or on the 

commodity. 

- -

Commodity Parts per million 

Pea, licld, seed 0.05 

Rhubarb 0. 1 

(d) Indirect or inadvertent residues. Tolerances are established for indirect or inadvertent residues of the herbicide 

propyzamide, including its metabolites and degradates, in or on the commodities in the table in this paragraph. 

Compliance with the tolerance levels specified in this paragraph is to be determined by measuring only those 

propyzamide residues convertible to methyl 3.5-dichlorobenzoate, expressed as the stoichiometric equivalent of 

propyzamide, 3,5-dichloro-N-( I, l-dimethyl-2-propynyl)benzamide, in or on the commodity. 

G 

G 

G 

Commodity 

rain, cereal, forage, group 16 

rain, cereal, hay, group 16 

rain, cereal, straw, group 16 

Page 20 of20 

Parts per million 

0.6 - 0.2 

0.3 -
Volume 3 

Annex B 

Propyzamide (Pronamide) 

B.5 METHODS OF ANALYSIS 

B.5.2 ANALYTICAL METHODS FOR THE DETERMINATION OF RESIDUES 

(ALL COMPONENTS INCLUDED IN THE RESIDUE DEFINITION PROPOSED) 
Propyzamide [PC Code I 0 170 I]/ Dow AgroSciences LLC 

Note: This Data Evaluation Record (DER) was originally prepared under contract by Versar. Inc. (6850 Versar Center. 

Springfield, VA 22151: submillcd 5/21115). The DER has been reviewed by HED and revised to rcnect current Office of 

Pesticide Programs (OPP) policies. 

Table B.5.2- 1. Overview of the Analytical Methods for the Determination of Pronamide Residues. 

Data Matrix Analytcs Method Type Limit of Quantitation Reference 

Requirement (ppm) 

Enforcement Lettuce Propyzamide and GLC/ECD 0.2 PAM Vol. II. 

Method- Plant its metabolites Method I 

Commodities convertible to Residue Chemistry 

methyl 3.5- Chapter for 

diehlorobenzoate Pronamide TR.ED. 

(MDCB) DP#275536. J. 

Morales. 2/28/02 

Data-Gathering Acidic crons: Propyzamide and GC!MS 0.01 Study No. 0410 I 0 

Method- Plant apple; lemon: metabolites (common moiety) MRID 49126806 

Commodities orange: orange containing the 3.5-

peel and pulp dichlorobenzoyl 

Orv crons: moiety. including: 

alfalfa forage. RH-24580. RHhay. and seed: 246M. RI 1-24848. 

barley forage. RH-25891. and 

grain. and straw: RH-26521 

corn forage, 

grain. and stover: 

wheal forage, 

grain. and straw 

Oil~1 croes: 

canola seed: 

olive oil: 

soybean seed: 

sunno"er seed 

Wet crons: 

broccoli: grape: 

green bean; 

lettuce: potato 

ILV of Not required for the 

Enforcement P/\M, Volume II . 

Method- Plant Method I. for plants 

Commodities because the primary 

enforcement method 

is the PAM MRM. 

Radiovalidation Alfalfa Propyzamide and GLC!ECD 0.2 PAM Vol. II. 

of Methods - Lelluce its metabolites Method I 

Plant convertible to Residue Chemistry 

Commodities methyl 3,5- Chapter for 

di ch lorobenzoate Pronamidc TRED. 

(MDCB) DP#275536. J. 

Morales, 2/28/02 

Enforcement PAM Vol. II. 

Method- Method I 

Livestock (TR 34-91-68) 

Commodities Residue Chemistry 

Chapter for 

Pronamide TRED. 

DP#275536. J. 

Morales. 2/28/02 

EPA MRID #: 46413406 Page 2 of 10 
Propyzamide (PC Code I 0170 I]/ Dow AgroSciences LLC 

T a ble B.5.2-1. Overview of the Analytical Methods for the Determination of Pronamide Residues. 

Data Matrix Analytcs Method Type Limit ofQuantitation Reference 

Requirement (ppm) 

Dara-Gathering 513185 Residue 

Method- Chemistry Chapter 

Livestock of the Registration 

Commodities Standard (MRIDs 

00 I 07959 and 

00107967) 

lLVof Chicken fat Propyzamide and GC/MS 0.01 Study o.020063 

Enforcement Oovine liver metabolites lGRM 02.21] MRJD 46414306 

Method- containing the 3.5- (common moiety) DP# 427081 

Livestock dichlorobenzoyl 

Commodities moiety 

Radiovalidation Not avai lable 

of Methods -

Livestock 

Commodities 

Multiresidue f-DJ\-Pestieide Residue Chemistry 

Method Testing Analytical Chapter for 

Methods Multi- Pronamide TRED. 

Residue testing DP#275536. J. 

program Morales. 2128/02 

MRID 43493203 

Table B.5.2-2. C hemical Structures of Analytes Addressed by Methods for the Analysis of Propyzamide. 

Method ID Chemical Name Chemical Structure 

GRM 02.21 Common Name: 

C

Propyzamidc 

hemical Na

(

me: 

Pron

3.5-

amide) 

av~ I 0 N Cit, ~II 

dichloro-N-( I. I-dimethyl2-prop) nyl)bcnzamidc Cl 

GRM 02.21 Common Na me: 3,5- CP-fl DCB/\ (common moiety) 

Chemical Name: 3,5- C-OH 

di ch lorobcnzoic acid 

Cl 

GRM 02.2 1 Common Name: 2,3-

cO-R DCBA (common moiety) 

Chemical Name: 2.3- C-OH 

dichlorobcnzoic acid 

B.5.2.J Analytical Methods for Plant Matrices (Annex llA 4.3, Annex IHA 5.3) 

Not applicable. 

EPA MRID #: 46413406 Page 3of10 
Propyzam idc [PC Code I 0170 I)/ Dow AgroSciences LLC 

B.5.2.2 

B.5.2.2.1 

Document ID: 

Report: 

Guidelines: 

GLP Compliance: 

Acceptability: 

Evaluator: 

Analytical Methods for Foodstuff of Animal Origin (Livestock 

Matrices; Annex IIA 4.3, Annex lllA 5.3) 

Post-Registration Method (Enforcement) 

MRID No. 46413406 

Reed, R. (2002) Independent Laboratory Validation of Dow AgroSciences 

LLC Method GRM 02.21 - Determination of Residues of Propyzamide in 

Animal Tissues by Gas Chromatography with Negative-Ion Chemical 

Ionization Mass Spectrometry. Study Nos. 020063 and ML02-I029-

DOW. Unpublished study prepared by Dow AgroSciences LLC. 82 p. 

EPA OCSPP Hannonized Test Guideline 860.1340 Residue Analytical 

Method (August 1996) 

PMRA Regulatory Directive DIR98-02 - Residue Chemistry Guidelines, 

Section 3 - Residue Analytical Method 

EU SANCO 825/00/rev. 7 (17/3/04) 

OECD Guidance Document on Pesticide Residue Analytical Methods 

No deviations from regulatory requirements were reported which would 

have an impact on the validity of the study. 

The study is considered scientificall y acceptable. The acceptability of this 

study for regulatory purposes is addressed in the forthcoming U.S. EPA 

Residue Chemistry Summary D~;nent, DP# 42708 l. 

ldeliz Negr6n-Encarnaci6n ry 

EXECUTIVE SUMMARY 

Dow AgroSciences LLC has submitted the results of an independent laboratory validation (IL V) 

of a gas chromatography method with negative-ion chemical ionization mass spectrometry 

detection (GC/MS), Method GRM 02.2 1, for the determination of residues of propyzamide 

(pronamide) and metabolites containing the 3,5-dichlorobenzoyl moiety as 3,5-dichlorobenzoic 

acid (3,5-DCBA) in poultry fat and bovine liver. The ILV was conducted by Morse Laboratories 

(Sacramento, CA). In addition to the IL V report, the submission included a complete method 

description of the original method, along with supporting method validation data for milk, 

bovine liver, kidney, muscle, and fat, and eggs and poultry muscle and fat. 

For the method as written, fat samples were extracted with ethyl acetate, evaporated to dryness, 

and redissolved in 1,4-dioxane. The samples were then hydrolyzed by adding 9 N sulfuri c acid 

and heating at 100 °C for at least 12 hours. During hydrolysis. bound residues of propyzamide 

and metabolites were solubilized and hydrolyzed to 3,5-DCBA. Samples of milk, eggs, and 

tissues other than fat were extracted and hydrolyzed by adding 4 N sodium hydroxide and 

heating at 80 °C for at least l 2 hours. During this initial hydrolysis, bound residues of 

propyzamide and metabolites were solubili zed and hydrolyzed to 3,5-DCBA. Following alkaline 

hydrolysis, the sodium hydroxide solution was acidified with 12 N HCl (pH <2) and extracted 

and hydrolyzed as described above for fat samples. During the second hydrolysis, the bound 

residues of propyzamide and metabolites were further solubilized and hydrolyzed to 3,5-DCBA. 

Following hydrolysis, all samples were cleaned up using an NH2 solid phase extraction (SPE) 

column. Residues were eluted with dichloromethane:formic acid (98:2, v:v). After elution, 

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acetone with peanut oil was added as a keeper, the eluate was evaporated to dryness, and 

residues were redissolved in isooctane:acetone (80:20, v:v). An internal standard, 2,3-

dichlorobenzoic acid-tert-butyldimethylsilate (2,3-DCBA-TBDMS), and a derivatizing agent, Nmethyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTF A), were added, and the sample 

was derivatized for 60 minutes at 60 °C. After cooling, residues were analyzed by GC/MS. The 

method monitors two ions for determination of 3,5-DCBA following derivatization. The limit of 

quantitation (LOQ, determined as the lowest limit of method validation; LLMV) is 0.01 ppm. 

The reported limit of detection is 0.003 ppm. The method provides for quantitation of residues 

in parent equivalents by use of calibration standards prepared in propyzamide equivalents. 

The method as written was adequately validated using samples of milk, bovine kidney, liver, 

muscle, and fat, and eggs and poultry muscle and fat fortified with propyzamide at 0.01, 0.05, 

0.25, and 0.50 ppm. Recoveries were within the acceptable range of 70-120% at all fortification 

levels. Overall mean recoveries (and relative standard deviations) for propyzamide were: 86% 

(4.5%) for milk, 92% (6.8%) for bovine kidney, 93% (7.3%) for bovine liver, 94% (19%) for 

bovine muscle, 90% (8.6%) for bovine fat, 98% (3.0%) for egg, 92% (6.7%) for poultry muscle, 

and 91 % (7.7%) for poultry fat. 

An IL V study for GC/MS method GRM 02.21 was conducted by Morse Laboratories, Inc. 

(Sacramento, CA) using samples of untreated bovine liver and chicken fat obtained from Dow 

AgroSciences fortified with propyzamide at 0.0 1, 0.10, and 0.50 ppm (LOQ, 1 Ox the LOQ, and 

50x the LOQ, respectively). 

The ILV was successful on the first attempt with chicken fat; recoveries were within the 

acceptable range of 70-120%. One recovery (268%) at the LOQ fo1tification level was 

determined to be an outlying data point using the Grubb's Method and was excluded from the 

statistical calculations. The ILV was also considered successful on the first attempt with bovine 

liver. The first GC run was suspect due to an unacceptable calibration curve generated from the 

derivatized analytical standards accompanying the sample set. This was determined to be the 

result of a double addition of internal standard to two of the calibration standards. The original 

GC-ready extracts were re-injected against a new set of derivatized analytical standards, and 

recoveries were within the acceptable range of 70-120%. Apparent residues of propyzamide 

were below the LOQ ( <0.0 1 ppm) in/on two unfortified samples each of chicken fat and bovine 

liver. 

The ILV laboratory provided a table detailing a ll communications with the method developer 

during the study. The IL V laboratory reported that profiling the elution pattern of the NH2 SPE 

cartridge prior to analysis of actual samples is imperative and identified this as a critical step. 

The IL V laboratory reported that excluding overnight incubation, one set of 16 chicken fat 

samples required approximately 14.5 person hours 2 calendar days) and one set of 16 bovine 

liver samples required 13.5 person hours (- 2 calendar days) to prepare sample extracts for GC 

analysis. Automated GC analysis was conducted overnight. 

No confirmatory analysis procedures were included. The registrant indicated that the GC/MS 

method is specific for the determination of propyzamide and metabolites as 3,5-DCBA by virtue 

of the chromatographic separation and selective detection system used. Confirmation is by 

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Propyzamide [PC Code I 01701 ]/ Dow AgroSciences LLC 

comparison of the retention time (GC) as well as the peak area ratio resulting from selected ion 

monitoring following MS analysis in the negative chemical ionization mode. 

No radiovalidation data were submitted. Analytical methods should be radiovalidated to 

determine whether total toxic residues (TTR) are extracted from weathered residues. This issue 

is addressed in 0427801 . 

I. Principle of the Method: GRM 02.21 

Table B.5.2.2.1-1. Summ ary Parameters fo r the Post-Registration Analytical Method for the Ana lysis of 

Propyzamide Residues in A n imal Tissues. 

Method ID GRM 02.2 1 

Analyte(s) Propyzamide and metabolites containing the 3.5-dichlorobenzoyl (DCBA) moiety 

Extraction solvent and Fat samples were extracted with ethyl acetate and centrifuged. An aliquot of the extract was 

technique evaporated to dryness, redissolved in 1.4-dioxanc, and hydrolyzed by adding 9 N sulfuric acid and 

heating at I 00 °C for at least 12 hours. During hydrolysis, bound residues of propyzamide and 

metabolites were solubilized and hydrolyzed to 3,5-DCBA. 

Samples of milk. eggs. and tissues other than fat were extracted and hydrolyzed by adding 4 N 

sodium hydroxide and heating at 80 °C for at least 12 hours. During this initial hydrolysis, bound 

residues of propyzamide and metabolites were solubi lized and hydrolyzed to 3,5-DCBA. 

Following alkaline hydrolysis, the sodium hydroxide solution was acidified with 12 N HCI (pH 

<2), sodium chloride was added, and the mixture was partitioned with ethyl acetate and 

centrifuged. An aliquot of the ethyl acetate phase was evaporated to dryness, redissolved in 1,4-

dioxane. and hydrolyzed by adding 9 N sulfuric acid and heating at I 00 °C for at least 12 hours. 

During the second hydrolysis, bound residues of propyzamide and metabolites were further 

solubi lizcd and hydrolyzed to 3.5-DCBA. 

Clean-up strategics For all samples following hydrolysis, the sulfuric acid hydrolysalc was partitioned with ethyl 

acetate, and the ethyl acetate phase was evaporated to dryness and redissolved in ethyl acetate. 

The sample was c leaned up using an Nl-12 SPE column. Residues were eluted with 

dichloromethane:formic acid (98:2, v:v). Aller elution, acetone with peanut oil was added as a 

keeper, the eluate was evaporated to dryness, and residues were redissolved in isooctane:acetone 

(80:20, v:v). An internal standard, 2,3-DCBA-TBDMS, and a derivatizing agent, MTBSTF A, 

were added and the sample was dcrivatizcd for 60 minutes at 60 °C. After cooling. residues were 

analyzed by GC/MS. 

Instrument and Detector GC/MS using a Restek capillary column. Rtx-50 liquid phase 

MS detection operated in the negative-ion chemical ionization mode with selected ion monitoring. 

The following ions were monitored: 

3.5-DCBA-TBDMS: ml= 304 (quantitation) and m/z 306 (confirmation) 

2,3-DCBA-TBDMS (internal standard): mlz 155 (quantitation) and mlz 304 (confirmation) 

Standardization method External standardization using a 8-point calibration curve (linear regression. least squares fit). 

Calibration standards of 3,5-DCBJ\ arc prepared in propyzamidc equivalents and derivatized prior 

to analysis. 

Internal standardization using an internal standard of2.3-DCBA-TBDMS 

Stability of std solutions Stability of the standard solutions was not reported. 

Retention times 3,5-DCBA: 9.51 minutes 

2,3-DCBA (internal standard): I 0.29-10.30 minutes 

The method provides for quantitation of residues in parent equivalents by use of calibration 

standards prepared in propyzamide equivalents. 

II. Specificity 

The GC/MS method is specific for the determination of propyzamide and metabolites as 3,5-

DCBA by virtue of the chromatographic separation and selective detection system used. 

Confirmation is by comparison of the retention time (GC) as well as the peak area ratio resulting 

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Propyzamide [PC Code I 01 70 I)/ Dow AgroSciences LLC 

from selected ion monitoring following MS analysis in the negative chemical ionization mode. 

Analysis of control samples resulted in no significant signals at the expected retention times of 

the analytes. Unambiguous identification of the common moiety is ensured by monitoring two 

ions during MS determination as follows: 

3,5-DCBA (derivatized) mlz 304 (quantitation) 

mlz 306 (confirmation) 

Confirmation of the presence of the propyzamide and metabolites (as 3,5-DCBA) in the recovery 

samples was indicated when the retention times of the analytes in the san1ples matched the 

retention times of the analytes in the calibration standards and the confirmation ratios (m/z 

306/304) of the analytes in the samples were ±20% of the average confirmation ratios of the 

standards. The confirmation ratios for each analyte were determined by calculating the ratio of 

the confirmation peak area to the quantitation peak area. The confirmation ratios for each 

analyte in representative sample matrices of bovine muscle and fat were within ±20% of the 

average confirmation ratios of the standards, indicating that the method is selective for the 

determination of propyzamide and metabolites (as 3.5-DCBA) in animal tissues and fat. 

I II. Linearity 

For propyzamide (as 3,5-DCBA), the linearity of detector response was evaluated using solvent 

standard solutions. Cali bration curves were calculated by linear regression analysis. For the 

least-squares equation, which describes the detector response as a function of the standard 

concentration, a representative calibration curve reflecting injection of eight standards over the 

concentration range of 0.075-1 2.50 ng/mL 3,5-DCBA (equivalent to 0.003-0.5 μgig 

propyzamide) demonstrated linearity with a coefficient of determination (r2) of 0.99983. 

IV. Accuracy (Recovery) and Precision (Repeatability) 

Radiovalidation. No radiovalidation data were included in the submission. Analytical methods 

should be radiovalidated to determine whether total toxic residues (TTR) arc extracted from 

weathered matrices. This issue is addressed in 0427801. 

Method validation. The method as written was adequately validated using samples of milk, 

bovine kidney, liver, muscle, and fat, eggs, and poultry muscle and fat fortified with 

propyzarnide at 0.01 , 0.05, 0.25, and 0.50 ppm. Recoveries were within the acceptable range of 

70-120% at all fortification levels. Overall mean recoveries (and relative standard deviations) 

for propyzamide were: 86% (4.5%) for milk, 92% (6.8%) for bovine kidney, 93% (7.3%) for 

bovine liver, 94% (19%) for bovine muscle, 90% (8.6%) for bovine fat, 98% (3.0%) for egg, 

92% (6.7%) for poultry muscle, and 91 % (7.7%) for poultry fat. 

Repeatability data were generated from at least two samples fortified at the LOQ and one or two 

samples each fortified at 5x LOQ, 25x LOQ, and 50x LOQ for each matrix. The standard 

deviations (RSDs) obtained were less than 19%. Recovery and repeatability data are presented 

in Tables B.5.2.2.1-3, below. 

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Ta ble B.5.2.2.1-3. Accuracy a nd Precision Da ta fo r the Validation of GRM 02.21. 

Analyte Matrix Fortification Validation Recovery(%) RSD 

Level (ppm) Individual Mean Range (%) 

Propyzamide Milk 0.01 83, 84 86 83-92 4.5 

111/z 304 for 3,5- 0.05 92 

DCBA 0.25 84 (quantitation) 0.50 89 

13ovinc 0.01 89.99 92 84-99 6.8 

kidney 0.05 91 

0.25 98 

0.50 84 

Bovine liver 0.01 96, 100 93 82-100 7.3 

0.05 93 

0.25 82 

0.50 95 

Bovine 0.01 97. 110 94 74-113 19 

muscle 0.05 74 

0.25 78 

0.50 113 

Bovine fat 0.01 79. 95. 10 1 90 79-1 0 1 8.6 

0.05 85.96 

0.25 89, 95 

0.50 79, 88 

Egg 0.01 99. 103 98 95-103 3.0 

0.05 95 

0.25 97 

0.50 98 

Poultry 0.01 97, 92 92 82-97 6.7 

muscle 0.05 82 

0.25 97 

0.50 94 

Poultry fat 0.01 94. 81. I 0 I. 99 9 1 81-101 7.7 

0.05 82, 86 

0.25 93,98 

0.50 87.87 

Independent Laboratory Validation CILV). An lLV study for GC/MS method GRM 02.21 was 

conducted by Morse Laboratories, Inc. (Sacramento, CA) using samples of untreated bovine 

liver and chicken fat, obtained from Dow AgroSciences, fortified with propyzan1ide at 0.01 , 

0.10, and 0.50 ppm and analyzed according to the method procedures described in Table 

B.5.2.1.1- 1. It was noted that minor modifications were necessary due to different laboratory 

equipment (water bath, centrifuge, evaporator, incubator, oven, ultrasonic cleaner, vacuum 

manifold, vortex mixer, SPE cartridge, glassware); however none of these adaptations had any 

infl uence on the results. 

The results of the ILV are presented in Table B.5.2.2.1 -4. The IL V was successful on the first 

attempt with chicken fat. One recovery (268%) at the LOQ fortification level was determined to 

be an outlying data point using the Grubb's Method and excluded from the statistical 

calculations. Recoveries were within the acceptable range of 70-120%. The IL V was also 

considered successful on the first attempt with bovine liver. The first GC run was suspect due lo 

an unacceptable calibration curve generated from the derivatized analytical standards 

accompanying the sample set which was the result of a double addition of internal standard to 

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Propyzamide [PC Code I 0170 I]/ Dow AgroSciences LLC 

two of the calibration standards. The original GC-ready extracts were re-injected against a new 

set of derivatized analytical standards and recoveries were within the acceptable range of 70-

120%. Apparent residues of propyzamide were below the LOQ (<0.01 ppm) in/on two 

unfortified samples each of chicken fat and bovine liver. 

The IL V laboratory reported that profiling the elution pattern of the NH2 SPE cartridge prior to 

analysis of actual samples is imperative and identified this as a critical step. 

There were several communications between the Study Director at the confirmatory laboratory 

and the method developers or others fami liar with the method. These are listed below: 

• Availability of clean control matrices 

• Approval of equivalent glassware and equipment 

• The Study Director asked for instruction on how to dilute samples with analyte responses 

falling outside the range of responses in the standard curve. Instructions were to dilute 

the samples twofold with 20% acetone/80% isooctane solution (containing no internal 

standard) prior to injection. 

• Discussion of typographical errors within the method write-up 

• Results of the first chicken fat ILV trial reported and discussed. Discussion regarding the 

high recovery at the LOQ and whether to treat it as an outlier if shown to be so by the 

Grubb's test. 

• Discussion of the results from the first bovine liver trial and the unacceptable calibration 

curve that was produced. The Study Director suggested that a new set of derivatized 

calibration standards be prepared and to re-inject the original sample set with the new 

standards. This course of action was approved. 

• Results of the first bovine liver IL V trial repo11ed and approved. 

The IL V laboratory reported that excluding overnight incubation, one set of 16 chicken fat 

samples required approximately 14.5 person hours (- 2 calendar days) and one set of 16 bovine 

liver samples required 13.5 person hours (- 2 calendar days) to prepare sample extracts for GC 

analysis. Automated GC analysis was conducted overnight. 

Table B.5.2.2.1-4. Accuracy and Precision Data for the Independent Laboratory Validation of GRM 02.21 

fo r Livestock Matrices. 

Analyte Matrix Fortification Independent Laboratory Validation Recovery(%) RSD 

Level (ppm) Individual Mean Range (%) 

Propyzamide Chicken fat 0.01 2681

, 106, 102, 114, 9 1 103 91- 11 4 9.2 

ml= 304 for 3.5- 0.10 103, 92, 95. 106, 84 96 84-106 8.9 

DCB/\ 0.50 79,88, 70 79 70-88 11.3 (quantitation) Bovine liver 0.01 I 05. I 08, I 09, 98, 94 103 94-109 6.3 

0.10 100, 120, 120, 100, 110 110 100- 120 9.0 

0.50 11 6, 111 . 111 113 111-116 2.6 

1 Value determined to be an outlying data point using the Grubb 's Method. Not used for statistical purposes. 

V. Limit of Quantitation 

Table B.5.2.2.1-5. Summa ry of Detection and Quantitation Limits for GRM 02.21. 

Anal)1e I LOO (ppm)' I LOQ (ppm)2 

Propyzamide. as 3.5-DCBA I 0.003 I 0.01 

1 LOD = limit of detection. 

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2 LOQ = limit of quantitation, defined as the lowest fortification level where acceptable precision and accuracy data were 

obtained. 

VI. Conclusions 

The GC/MS Method GRM 02.21 was adequately validated for determining residues of 

propyzamide and metabolites containing the 3,5-dichlorobenzoyl moiety as 3,5-DCBA following 

derivatization in milk, bovine tissues (kjdney, liver, muscle, and fat), eggs, and poultry tissues 

(muscle and fat). The validated LOQ is 0.01 ppm, and the LOO is 0.003 ppm. Additional 

information/data pertaining to radiovalidation are needed. 

The submitted IL V study is acceptable. Adequate recoveries were obtained for chicken fat and 

bovine liver fortified with propyzamide at 0.0 I (LOQ), 0.10 ( 1 Ox LOQ), and 0.50 ppm (50x 

LOQ). 

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