Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY

AND POLLUTION PREVENTION

MEMORANDUM

May 12, 2010

SUBJECT: Diquat Dibromide Petition for the Establishment of Permanent Tolerances for 

New Use on Canola. Summary of Analytical Chemistry and Residue Data.

PC Code: 032201 DP Barcodes: D375811

Decision Nos.: 423144 Registration Nos.: 100-1061

Petition Nos.: 9F7639 Regulatory Action: Section 3

Risk Assessment Type: NA Case No.: 0288

TXR No.: NA CAS No.: 85-00-7

MRID No.: See MRID Summary Table 40 CFR: 180.226

 

FROM: Becky Daiss, Biologist

Risk Assessment Branch 4

Health Effects Division (7509P)

THROUGH: Susan Hummel, Senior Scientist

Risk Assessment Branch 4

Health Effects Division (7509P)

TO: Bethany Benbow, Risk Manager Reviewer

Herbicide Branch

Registration Division (7508P)

MRID Summary Table

MRID No. Study Type Comments

47910101 860.1500 Canola Summarized in new DER; 47910101.der.doc

47910102 860.1500 Canola Summarized in new DER; 47910101.der.doc

47910103 860.1340 Canola Summarized in new DER; 47910103.der.doc
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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Executive Summary

Diquat dibromide (6,7-dihydrodipyrido(1,2-a:2', 1'-c)pyrazinediium dibromide) is a non-selective 

contact herbicide, desiccant, and plant growth regulator primarily registered as a general 

herbicide for the control of broadleaf and grassy weeds on terrestrial non-crop and aquatic areas. 

Diquat dibromide is also registered as a preharvest desiccant in potato and crops grown for seed 

including alfalfa, carrot, clover, radish, sorghum, soybean, and turnip. Special local need 

registrations have recently been granted for the use of diquat dibromide as a postharvest 

desiccant on cantaloupe, cucumber, pepper, squash, tomato, and watermelon. The diquat 

dibromide formulations registered for use on aquatic areas and food/feed crops are the 0.2 and 2 

lb cation/gal soluble concentrate/liquid (SC/L). On crops, these formulations may be applied as 

preplant or preemergence broadcast applications or as preharvest/postharvest desiccants using 

ground or aerial equipment. On noncrop aquatic areas, the formulations registered may be 

applied as surface, sub-surface, or bottom placement treatments [Source: REFS search, 8/7/01].

The established tolerances for residues of diquat dibromide in/on raw agricultural commodities 

and in animal products are presently expressed in terms of the diquat cation [Source: 40 CFR 

§180.226 (a) and (b)]. Tolerance levels of 0.05-0.1 ppm are established for crop commodities 

and 0.02 ppm for animal commodities. 

Under PP#9F7639, Syngenta Crop Protection Inc is supporting the use of diquat dibromide as a 

harvest aid dessicant on canola. Syngenta has submitted the label Reglone Desiccant (EPA Reg. 

No. 100-1061). Reglone Dessicant is a soluble concentrate containing 3.73 lbs diquat dibromide 

salt per gallon equivalent to 2 lbs diquat cation per gallon. An application rate of 0.5 lb ai/A is 

proposed with a limit of one application per season. A 7 day pre harvest interval (PHI) is 

required with harvest no later than 10 days after application. Ground or aerial application 

equipment is permitted. 

The registrant is also proposing an HPLC analytical method as a new enforcement method for the 

determination of residues of diquat in crops, including oil seed crops (Analytical Method 

Number RAM 272/02, “The Determination of Residues of Paraquat and Diquat in crops and Soil 

– A High Performance Liquid Chromatographic Method”). 

Regulatory Recommendations and Residue Chemistry Deficiencies

HED has examined the residue chemistry database for diquat dibromide. There are no residue 

chemistry issues that would preclude establishing a tolerance and granting a conditional 

registration for the requested use of diquat dibromide or establishment of the following 

tolerances for residues of the diquat cation dibromide:

Canola, seed .....................................................................................2.0 ppm

Canola, meal ....................................................................................6.0 ppm

The registration is conditional based on the submission the IR-4 data on preharvest dessicant use 

of diquat dibromide on canola. 

Syngenta Crop Protection, Inc. has submitted field trial data from studies conducted in W. 
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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Germany and the UK to support use of diquat dibromide as a preharvest dessicant on canola. No 

field trial data from the United States or Canada are currently available. However IR-4 is 

currently conducting studies for preharvest dessicant use of diquat dibromide on canola. 

The HED ChemSAC determined that the EU data would support the establishment of a tolerance 

of 1 ppm on canola seed and the conditional registration of diquat dibromide on canola as a 

harvest aid/desiccant. The tolerance on canola seed has been increased from 1 ppm to 2 ppm to 

harmonize with the Codex MRL, and a tolerance of 6 ppm is recommended for canola meal, 

based on a maximum theoretical concentration factor of 3X. HED is aware that IR-4 is currently

conducting studies in the U.S. to support the preharvest desiccant use of diquat dibromide on 

canola. Residues of diquat dibromide on canola grown in the U.S. are not expected to differ 

significantly from residues reported in the EU studies, since harvest aid/desiccant applications 

are made late in the growing season with little time between application and harvest. In addition, 

since the recommended tolerances for canola seed and meal have been increased by a factor of 

2X to harmonize with Codex, there is little chance residues in the U.S. trials will exceed these 

tolerances. Nevertheless, since the IR-4 field work has already been completed and the study

reports will be available in July, 2011, HED recommends that these studies be required as a 

condition of registration to confirm the recommended tolerance levels.

Syngenta provided insufficient information on storage durations/conditions of canola samples in 

the European crop field trials for use of diquat as a dessicant on canola. Data on length of 

storage of canola samples prior to analysis from the W. German and UK trials is required. 

Although the length of storage prior to analysis is unknown, based on the structure of diquat, 

residues in frozen storage are expected to be stable much longer than the 6 to 8 months for which 

storage stability data are available. Therefore, lack of data on length of storage is not expected to 

impact the risk assessment. 

Syngenta has proposed a new enforcement method - Analytical Method Number RAM 272/02 

“The Determination of Residues of Paraquat and Diquat in crops and Soil – A High Performance 

Liquid Chromatographic Method.” Samples are extracted by refluxing in dilute sulphuric acid.

The filtered digest is diluted and percolated through a column of cation exchange resin which 

retains the diquat. The column is washed with a hydrochloric acid, ammonium chloride and 

deionized water solution. Diquat residues are eluted with saturated ammonium chloride solution. 

Final determination of diquat residues is made with ion-pair HPLC with UV detection. Reports 

on the method validation (RJ201B) and the ILV (ZEN 0396) have been submitted to the Agency. 

Based on HED’s analysis, the proposed analytical method is classified as scientifically

acceptable.

HED recently completed a risk assessment for a Section 18 Emergency Exemption for use of 

diquat dibromide on canola grown in Oklahoma and Kentucky (M. Doherty, D355407, 12/3/09). 

The use requested for this Section 3 registration is identical to that assessed for the Section 18 

request. Therefore a new risk assessment is not needed. 

Background

Diquat dibromide is a non-selective contact herbicide, algicide, dessicant, and defoliant. As a 

herbicide/algicide, it is used to control aquatic and terrestrial weeds. It is used as a preharvest 
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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dessicant/defoliant to facilitate the harvest of potatoes and various crops grown for seed. 

Diquat dibromide works as a dessicant by reacting with molecular oxygen to produce a 

superoxide anion in treated plants. The oxidative activity, which occurs subsequent to formation 

of the oxygen radicals, rapidly destroys plant cell membranes. The nomenclature and 

physicochemical properties of diquat dibromide are shown in Tables 1 and 2. 

Table 1. Diquat dibromide and Diquat dibromide Potassium Salt Nomenclature

Chemical Structure

Common name Diquat dibromide

Company experimental name NA

IUPAC name 9,10-dihydro-8a,10a-diazoniaphenanthrene dibromide

CAS name 6,7-dihydrodipyrido[1,2-a:2′,1′-c]pyrazinediium dibromide

CAS # 85-00-7

End-use product (EP) Reglone Dessicant herbicide (EPA Reg No. 100-1061

Table 2. Physicochemical Properties of Diquat Dibromide

Parameter Value Reference

Mol Wt 344.1 (Cation – 184) The Pesticide Manual 11th

Edition

Melting point/range 300 °C D277710

pH Not Provided NA

Density (20°C) 1.22-1.27 The Pesticide Manual 11th

Edition

Water solubility (20°C) 700 g/L D277710.

Solvent solubility slightly soluble in alcohol and hydroxylic 

solvents, and

practically insoluble in nonpolar organic 

solvents

D277710

Vapour pressure at 20°C Negligible < 10-5 mbar The agrochemicals 

handbook 1983

Dissociation constant (pKa) Not Provided NA

KOW Octanol/water partition coefficient as 

Log POW at 20°C

-4.60 The Pesticide Manual 11th

Edition

UV/visible absorption spectrum Neutral and acidic conditions - one major 

peak at 309.5 nanometers. 

Basic conditions - two major peaks at 309.0 

and 217.0 nanometers.

D349998

860.1200 Directions for Use

The petitioner submitted a draft label for label Reglone Desiccant (EPA Reg. No. 100-1061). An 

application rate of 0.5 lb ai/A is proposed with a limit of one application per season. A 7 day pre 

harvest interval (PHI) is required with harvest no later than 10 days after application. Ground or 

aerial application equipment is permitted. 
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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Table 3. Summary of Directions for Use of Diquat Dibromide on Canola

Applic. 

Timing, Type, 

and Equip.

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 

Limitations

Harvest Aid

Broadcast

Aerial or 

Ground 

2 lb (diquat 

cation)/gal 

SC

[100-1061]

0.5 1 0.5 7

Harvest no later than 

10 days after 

application

Conclusions. The label is adequate to allow evaluation of the residue data relative to the 

proposed use. 

860.1300 Nature of the Residue - Plants

MARC Decision, DP# 277765, 11/8/2001, T. Morton

The reregistration requirements for plant metabolism are fulfilled. The qualitative nature of 

the residue in plants is adequately understood based on an acceptable potato metabolism 

study and a rat bioavailability study. The HED Metabolism Assessment Review Committee 

(MARC) has concluded the residue of concern for plants is the diquat cation (T. Morton, 

11/8/01, D277765). The established tolerance expression for residues of diquat dibromide 

in/on plant commodities is appropriate and no changes are required.

The potato metabolism study indicated that no metabolism of diquat occurred in potato tubers 

following preharvest application of [14C]diquat as a desiccant to potato stalks and stems. 

Soybean and wheat metabolism studies had also been previously submitted but were deemed 

marginal because of inadequate characterization and identification of 14C-residues in the 

commodities of concern. Attempts to further characterize 14C-residues from these studies 

were unsuccessful. In lieu of the requirements for additional crop metabolism studies, the 

Agency recommended several options to satisfy reregistration requirements for this topic. 

The registrant opted to conduct a bioavailability study. The results of the bioavailability

study showed that diquat plant residues are largely not bioavailable; <5% of the 14C is 

absorbed as a result of feeding diquat field residues in/on wheat chaff to rats. The retention 

of diquat residues in tissues was negligible (0.004 ppm diquat equivalents) following dosing 

at 25x the maximum human dietary intake.

860.1300 Nature of the Residue - Livestock

Canola meal is a livestock feedstuff. The qualitative nature of the residue in plants is adequately

understood and the terminal residue of concern in plants is the diquat cation. 

860.1340 Residue Analytical Methods

DER 47910103

Enforcement Methods: The Pesticide Analytical Manual (PAM) Vol. II. lists a 

spectrophotometric method, designated as Method A (also referenced as Chevron Chemical 

Company RM-8-7) as available for the enforcement of tolerances for residues of diquat per se
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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in/on plant and in animal commodities. In this method, residues are extracted with sulfuric acid 

to free diquat from the bound state, absorbed on cation exchange resin, and eluted with saturated 

ammonium chloride. The diquat in the eluate is reduced by sodium dithionate, forming an 

intense green color and is measured spectrophotometrically at 337 μm. The limit of detection is 

0.01 ppm.

The registrant is proposing analytical method number RAM 272/02 (“The Determination of 

Residues of Paraquat and Diquat in crops and Soil – A High Performance Liquid 

Chromatographic Method”) as an enforcement method for the determination of residues of diquat 

in crops, including oil seed crops. RAM 272/02 has a limit of detection (LOD) in the range of

0.01-0.05 mg/kg depending on the crop type and mass of sample analyzed. With this method, 

samples are extracted by refluxing in dilute sulphuric acid. The filtered digest is diluted and

percolated through a column of cation exchange resin which retains the diquat and some of the 

natural crop constituents. The column is washed with hydrochloric acid, ammonium chloride 

solution to remove endogenous materials. Diquat residues are eluted with saturated ammonium 

chloride solution. A portion of the column eluent is passed through a preconditioned C18 solid 

phase extraction cartridge to remove further co-extractives. Final determination of diquat 

residues is made using ion-pair high performance liquid chromatography. Samples are analyzed 

against an appropriate concentration of diquat standard dissolved in saturated ammonium 

chloride solution. Based on HED’s analysis, the proposed analytical method is classified as 

scientifically acceptable.

Data Collection Methods: Plant Protection Residue Analytical Method No.5 was used for the 

measurement of diquat ion residues in canola seed. The samples were heated under reflux in 0.5 

mol dm-3sulfuric acid solution. The filtered digest was percolated through a column of cation 

exchange resin which retained the diquat and some of the natural crop constituents. The column 

was sequentially washed with dilute hydrochloric acid solution, 2.5% ammonium chloride 

solution and water. The diquat was then eluted with saturated ammonium chloride solution. A 

portion of the column eluent was treated with sodium dithionite in alkali. This reduced the 

diquat to a free radical, the light absorption of which was measured using a spectrophotometer. 

The estimated LOD of the method was reported as 0.005 ppm in the UK study and 0.05 for the 

West German study. 

Plant Protection Residue Analytical Method No 7A was used for the measurement of diquat ion 

in canola oil samples for the West German trials. The oil samples were thoroughly mixed by

rolling with cation exchange resin for 2 hours. The resin was then placed in a column and was 

subjected to the same procedure as the seed samples. The LOD of the method was estimated to 

be 0.05 ppm. 

Conclusions: The data collection method used in the submitted field trials is similar to the 

existing enforcement method. Adequate method validation and concurrent recovery data were 

attained in the field trial and processing studies. Therefore, HED concludes that existing and 

proposed enforcement methods are adequate for enforcement of the existing tolerances. 
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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860.1360 Multiresidue Methods

The FDA's PESTDATA dated 11/6/90 (Pam Vol. I, Appendix) indicates that recovery of diquat 

dibromide using Multiresidue Protocols is unlikely. The updated PESTDATA dated 08/93 does 

not have an entry for diquat dibromide.

860.1380 Storage Stability

The requirements for storage stability data are fulfilled for purposes of reregistration. Adequate 

storage stability data on diquat dibromide are available to support the storage conditions and 

intervals of samples from magnitude of the residue studies in plants and animals. Residues of 

diquat per se are stable under frozen (-20C) storage conditions for: (I) up to six months in/on 

bell pepper, carrot roots, clover (hay and seed), lettuce, potato, rice (grain and straw), sorghum 

grain, soybean, tomato and tomato processed fractions, and wheat (grain and straw); (ii) up to 8 

months in processed fractions of sorghum grain and soybean; and (iii) up to 2 months in water 

and seafood samples.

Syngenta provided very limited information on storage durations/conditions of canola samples in 

the crop field trials for use of diquat as a dessicant on canola. For the West German trials, 

representative samples of seed were received deep frozen at Jealott’s Hill during September and 

October 1987; all samples were stored at -20 +/-5 oC prior to analysis. For the UK trials, samples 

were stored at -20oC prior to analysis. Data on length of storage prior to analysis was not 

provided. Although the length of storage prior to analysis is unknown, based on the structure of 

diquat, residues in frozen storage are expected to be stable much longer than the 6 to 8 months 

for which storage stability data are available. Therefore, lack of data on length of storage is not 

expected to impact the risk assessment. However, data on length of storage of canola samples 

prior to analysis should be submitted.

860.1400 Water, Fish, and Irrigated Crops

There proposed label changes do not impact water, fish or irrigated crops. Therefore, data 

requirements for this guideline topic are not relevant to the request for use on canola. 

860.1460 Food Handling

The requested label changes are not relevant to this guideline topic.

860.1480 Meat, Milk, Poultry, and Eggs

Canola meal is a livestock feedstuff. Recalculated dietary burdens are provided in Table 4. 

Current tolerances are adequate. Residues will not exceed those used in the dietary exposure 

analysis conducted for the Section 18 Emergency Exemption.

Table 4. Recalculated Dietary Burden

Feed Commodity % Dry Matter a % Diet a Est Residues (ppm) Dietary Contribution (ppm) b

Beef Cattle

 Canola Meal 88 5 6.0 0.34

 Soybean hulls 90 15 0.6 d0.10
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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 Potato processed waste 15 80 0.5 f2.66

 TOTAL BURDEN 3.11

Dairy Cattle

 Canola Meal 88 10 6.0 0.68

 Soybean hulls 90 20 0.6 d0.13

 Potato processed waste 15 40 0.5 f1.33

 Sorghum grain 86 30 2.0 e0.70

 TOTAL BURDEN 2.84

Poultry

 Soybean Seed NA 10 0.2 c0.04

 Canola Meal NA 15 6.0 d0.09

 Sorghum grain NA 75 2.0 e1.50

 TOTAL BURDEN 2.44

Swine

 Canola Meal NA 15 6.0 0.09

 Sorghum grain NA 85 2.0 e1.78

 TOTAL BURDEN 2.60

a Table 1 (OPPTS Guideline 860.1000, August 1996).

b Contribution = [tolerance / % DM (if cattle)] X % diet).

c Tolerance level for soybean seed.

d Tolerance level for soybean hulls.

e Tolerance level for sorghum grain.

f Tolerance level for potato processed waste (wet peel residue levels used).

In a cattle feeding study, residues of diquat were non-detectable (<0.003 ppm) in milk and tissues 

following feeding of diquat-treated ryegrass silage to cattle at 3.6 ppm (1.2x and 1.3x the 

maximum dietary intake for dairy and beef cattle, respectively) for 30 days. In another study, 

residues of diquat were nondetectable (<0.01 ppm) in milk following feeding of diquat-treated 

clover hay to cattle at 11 ppm (3.9x) for 34 days. The established 0.02 ppm tolerance level for 

diquat residues in milk is adequate. The established tolerances of 0.02 ppm for diquat residues in 

the fat, meat, and meat byproducts of cattle, goats, hogs, horses, and sheep may be raised to 0.05 

ppm to achieve compatibility with the Codex maximum residue limit (MRL).

The maximum dietary burden for poultry is 2.44 ppm; the calculation of the poultry burden is 

presented above. In a poultry feeding study, residues of diquat were mostly non-detectable 

(<0.005 ppm) in samples of eggs, fat, muscle, liver, and skin of chickens fed diquat at 1, 4.3, and 

8.2 ppm diquat cation (0.4x, 1.8x, and 3.4x, respectively, the estimated dietary burden) in the diet 

for 28 days. A single skin sample from the day-21, 8.2 ppm treatment group bore residues of 

0.006 ppm. Residues in gizzard ranged from non-detectable to 0.022 ppm. The established 0.02-

ppm tolerance level for diquat residues in poultry fat, meat, meat byproducts and eggs may be 

raised to 0.05 ppm to achieve compatibility with the Codex maximum residue limit (MRL).

860.1500 Crop Field Trials

DER References: 47910101.der.doc

Syngenta Crop Protection, Inc. has submitted field trial data for use of diquat dibromide as a 

preharvest dessicant on canola preharvest dessicant on canola. Field trials were conducted in 

West Germany and the United Kingdom. No field trial data from the United States or Canada 

are currently available. However IR-4 is currently conducting studies for preharvest dessicant 

use of diquat dibromide on canola. Data from the IR-4 studies is expected to be available by July 
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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2011. The results of the field trials conducted in Europe are summarized in Table 5.

TABLE 5. Summary of Residue Data from Crop Field Trials with Diquat

Commodity Total Applic. 

Rate

(lb a.i./A)

(kg a.i./ha)

PHI 

(days)

Residue Levels

(ppm)

n Min. Max. HAFT* Median

(STMdR)

Mean

(STMR)

Std. Dev.

Canola Seed 0.54/0.6 5-8 10 <0.05 0.48 0.48 0.155 0.232 0.13

Canola Seed 0.54/0.6 10-13 2 0.03 0.21 0.38 0.12 0.12 0.13

Canola Seed 0.54/0.6 20 2 0.18 0.38 0.38 0.28 0.28 0.14

Canola Oil 0.54/0.6 5-8 8 <0.05 <0.05 <0.05 <0.05 <0.05 0

Conclusion. Based on ChemSAC’s recommendation that the diquat team consider requiring data 

from trials conducted in the U.S. to supplement the available European field trial data, 

submission of the IR-4 data should be required as a condition of the canola registration. 

860.1520 Processed Food and Feed

A maximum theoretical concentration factor of 3X has been applied for the processed fraction 

canola meal. Residue data from field trials conducted in Germany demonstrated that diquat 

residues were not found in any of the oil samples. 

860.1650 Submittal of Analytical Reference Standards

An analytical reference standard for diquat dibromide monohydrate is available in the Pesticide 

Standards Repository (Personal Communication, Theresa Cole 3/25/10).

860.1850 & 1900 Confined and Field Accumulation in Rotational Crops

There are no rotational crops associated with the proposed label changes. Therefore, data 

requirements pertaining to confined and field accumulation in rotational crops are not relevant to 

this tolerance petition.

860.1550 Proposed Tolerances

The residues of concern in plant and animal commodities is the diquat cation. The tolerances 

proposed by Syngenta and those recommended by HED are listed in Table 5. Codex has an 

established maximum residue limit (MRL) at 2 ppm Canada has an established tolerance of 1 

ppm. The residue definitions are identical. Therefore to harmonize with Codex HED 

recommends a tolerance of 2 ppm.

Tolerances are established in 40CFR 180.226 for residues of the plant growth regulator and 

herbicide diquat, (6,7-dihydrodipyrido (1,2-a:2'1'-c)pyrazinediium) derived from application of 

the dibromide salt and calculated as the cation. The current tolerance expression is adequate.
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Table 5. Tolerance Summary for Diquat Dibromide

Commodity Established/

Proposed Tolerance

(ppm)

Recommended

Tolerance

(ppm)

Comments; 

Correct Commodity Definition

Proposed tolerances under §180.226

Canola, seed 1.0 2.0

Canola, meal 3.0 6.0

References

DP#: 277710

Subject: Tolerance Reassessment of Diquat dibromide: Product and Residue Chemistry

Considerations.

From: T. Morton

To: R. Daiss

Dated: 12/13/2001

MRID: NA

Template Version September 2005
Diquat Dibromide Summary of Analytical Chemistry and Residue Data DP#: 375811

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INTERNATIONAL RESIDUE LIMIT STATUS

Chemical Name: 6,7-

dihydrodipyrido[1,2-a:2′,1′-

c]pyrazinediium dibromide

Common Name: 

Diquat

Proposed tolerance

 Reevaluated tolerance

 Other

Date: 4/1/10

Codex Status (Maximum Residue Limits) U. S. Tolerances

 No Codex proposal step 6 or above

 No Codex proposal step 6 or above for the crops 

requested

Petition Number 9F639

DP Barcode: 375811

Other Identifier:

Residue definition (step 8/CXL): Diquat cation.

Generally available as dibromide.

Reviewer/Branch: R. Daiss, RAB4

Residue definition: Diquat cation

Crop (s) MRL (mg/kg) Crop(s) Tolerance (ppm)

Rape seed 2 Canola

Limits for Canada Limits for Mexico

 No Limits

 No Limits for the crops requested

 No Limits

 No Limits for the crops requested

Residue definition: 9,10-dihydro-8a,10adiazoniaphenanthrene ionResidue definition: Mexico uses US tolerances and/or 

Codex MRLs for its export purposes.

Crop(s) MRL (mg/kg) Crop(s) MRL (mg/kg)

Rapeseed 1.0

Notes/Special Instructions: S. Funk, 04/01/2010