Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 2 of 37 Executive Summary

Chlorpyrifos is an organophosphate class insecticide that is currently used for insect control on a

variety of fruit, vegetable and field crops. The qualitative nature of the residue in plants and

live stock is adequately understood mainly based on acceptable metabolism studies with cereal

grain (corn), root and tuber vegetable (sugar beets), poultry and ruminant. The terminal residue

of concern in/on plants and livestock is chlorpyrifos per se . Tolera nces for residues of the

insecticide chlorpyrifos per se

, O,O

- diethyl O

- (3,5,6

- trichloro

- 2

- pyridyl) phosphorothioate, are

established under the 40 CFR §180.342.

The 2009 scoping document for chlorpyrifos registration review summarizes the status of the

residue chemistry database based on the Reregistration Eligibility Decision (RED) and the

mitigation measures addressed in the 2002 Interim Reregistration Eligibility Decision (IRED).

Since the 2000 assessment new crop field trial studies have been submit ted for cotton gin

byproducts, tart cherries, aspirated grain fractions for soybean, sorghum and wheat, and grass

forage and hay as part of a data call in related to the RED. These studies were reviewed

previously and a discussion is included in this docu ment for all the commodities with the

exception of grass forage and hay (original petition withdrawn). In addition, petitions for a PHI

reduction for sweet potato and the registration of a microencapsulated formulation were

submitted but the requests were cancelled and denied, respectively.

Currently, no petitions for the establishment of new tolerances for chlorpyrifos are pending.

Moreover, the petitions 7F7248 (alfalfa, alfalfa mixed stands, grass grown for hay or pasture),

3F4188 (barley grain and forage), and 3H5662 (barley, milling fractions) identified in the 2009

scoping document were withdrawn in 07/May/2009. Studies for clover were not received as part

of a Special Local Need action identified in the 2000 RED; therefore, tolerances for clover were

not established in the CFR.

Label restrictions prohibiting feeding of corn forage and stover to meat or dairy animals are not

considered practical (D266564, S. Knizner, 20/June/2000). A revision to Section 3 labels of corn

was performed and HED re commended removing pre

- foraging and pre

- grazing intervals from

the labels (D338439, C. Swartz, 28/March/2007). Based on this the SLN label DE930004 may

be revised to eliminate feeding restrictions.

Adequate enforcement and multiresidue analytical metho ds are available for analysis of

chlorpyrifos in crops, feed and animal commodities. Two data collections methods, a GC/MS

and a HPLC/MS method, were used and adequately validated in conjunction with the analysis of

samples for the field trials with cotto n and tart cherries and for the processing study with cereal

grains. For these methods, residues of chlorpyrifos are extracted with acetone/water and cleaned

up using a C 18 solid

- phase extraction (SPE) column, and 13 C 2 15 N

- chlorpyrifos is added as an

inter nal standard prior to analysis. Recoveries were within the acceptable range of 70

- 120%.

The crop field trial data requested in the RED and submitted by the petitioner is considered

adequate to establish a tolerance of 15 ppm for cotton gin by products a nd 22 ppm for aspirated

grain fractions, and to keep the current tolerance for tart cherries under the condition that onlyChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 3 of 37 dormant/delayed dormant and trunk spray applications remain on the label of the 75% WDG end

use product.

Studies submitted to suppo rt the registration of a new formulation of chlorpyrifos showed over

tolerance residues after a foliar application of Lorsban 4E end use product to lemon with a rate of

6 lb ai/A. The maximum residue observed in that study was at a concentration of 1.41 p pm

which is over the current tolerance for citrus fruit (CG 10), 1.0 ppm. The label of the Lorsban 4E

end use product (44.9% chlorpyrifos) allows a maximum application rate of 6.4 lb ai/A and

addition of oil to the spray mixture. Under these conditions r esidues over tolerance may occur;

therefore, HED recommends a reassessment of the tolerance for citrus fruit using lemon as the

representative commodity.

The dietary burden to livestock was recalculated to consider residues at tolerance level in the

feed stock commodities (aspirated grain fractions and cotton gin by

- products) included in this

assessment and to use the most current version of Table 1 (OPPTS Test Guidelines 860.1000)

released on June 2008. Based on the residues observed in the feeding study of cattle beef, dairy

cow, swine and poultry at the 1x and/or 3x level, HED concludes that the possible residues

obse rved on livestock commodities ( f rom animals f

ed with feedstock that may contain residues

resulting from legal applications) are covered by the current tolerances established in the 40 CFR

§ 180.342.

According OPPTS 860.1000 guideline several processing studies are required to establish a

tolerance for food/feed items that correspond to RACs treated with chlorpyrifos. Processing

studies a re required for: cotton meal, hulls and refined oil; soybean meal, hulls and refined oil;

and wheat hay. Moreover, the following tolerances can be reestablished to cover the processing

studies required: corn milled byproducts as 0.1 ppm; and wheat milled byproducts as 1.5 ppm.

Regulatory Recommendations and Residue Chemistry Deficiencies

HED has the following regulatory recommendations:

1. Revise the corn and cotton use restrictions in t he chlorpyrifos labels to eliminate feeding

restrictions in treated areas

.

2. Tolerances for c otton gin byproducts and aspirated grain fractions are recommended.

Cotton, gin byproducts

................................ ................. 15 ppm

A spirated grain fractions

................................ ............... 2 2 ppm

3. M aintain only dormant/delay dormant and trunk spray applications for tart cherries in the

la bel of the 75% WDG end use product.

4. Revocation of the tolerance for lettuce is in process as use s of chlorpyrifos in this crop

are not included in the label for the registered products.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 4 of 37 5. Magnitude of the residue studies with lemon af ter application of Lor sban 4E and 75%

WDG formulations separately to reassess the tolerance for the citrus fruit crop group.

6. Processing studies for:

a. Cotton meal, hulls and refined oil

b. Soybean meal, hulls and refined oil

7. Field trials to establish a tolerance for wheat hay.

8. R eestablish the tolerance for:

a. Corn milled by products as 0.1 ppm

b. Wheat milled by products as 1.5 ppm

9. EPA should inform the FDA about these illegal residues of chlorpyrifos detected in crops

and catfish for them to take the appropriate action.

10. Modificat ion of the tolerance expression for chlorpyrifos in the 40 CFR § 180.342 to

comply with the Interim Guidance for Writing Tolerance Expressions.

A revised human health risk assessment is being prepared as a separate document.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 5 of 37 Bac kground

Chlorpyrifos is an organophosphate class insecticide that is currently used for insect control on a

variety of fruit, vegetable and field crops. T olerance s for residues for residues of the insecticide

chlorpyrifos per se

, O,O

- diethyl O

- (3,5,6

- tri chloro

- 2

- pyridyl) phosphorothioate , are established

under the 40 CFR §180.342. As stated in the scoping document, 3,5,6

- t richloro

- 2

- pyridinol

(TCP) is no longer a residue of concern . On the other hand, the chlorpyrifos oxon was identified

as a residue of concern in drinking water but not for plants or livestock

.

T able 1. Chlorpyrifos Nomenclature.

Compound

Common name Chlorpyrifos

Company experimental name NA

IUPAC name O,O

- diethyl O

- 3,5,6

- trichloro

- 2

- pyridyl phosphorothioate

CAS name O,O

- diethyl O

- (3,5,6

- trichloro

- 2

- pyridinyl) phosphorothioate

CAS registry number 2921

- 88

- 2

End

- use product (EP) Lorsban 4E, Lorsban 75% WDG and Lorsban 50% WP (EPs used in the new

studies submitted and included in this chapter)

Metabolite

Common Name TCP

I UPAC Name 3,5,6

- t richloro

- 2

- pyridinol

Metabolite

(Residue of Concern for

Canada)

Common Name Chlorpyrifos Oxon

IUPAC Name O, O

- diethyl O

- (3,5,6

- trichloro

- 2

- pyridyl) phosphateChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 6 of 37 T able 2. Physicochemical Properties of Chlorpyrifos.

Parameter Va lue Reference

Melting point/range 41.5

- 42.5 oC Chlorpyrifos IRED

pH NR

Density (21oC) 1.51 g/mL

Water solubility (25°C) 1.05 mg/L

Solvent solubility (20°C) Ac etone >400 g/L Dichloromethane >400 g/L

Methanol 250 g/L Ethyl acetate >400 g/L

To luene >400 g/L n

- hexane >400 g/L

Vapor pressure, mPa at 25oC 3.35

Dissociation constant, pK

a NR

Octanol/water partition coefficient,

Log(K OW ) 4.7

UV/visible absorption spectrum NR

NR

– not reported.

860.1200 Directions for Use

Since the c hlorpyrifos IRED, studies were submitted to establish tolerances in cotton gin

byproducts and aspirated grain fractions after application of the 75% WG (EPA Reg. No. 62719

- 301) and/or Lorsban 4E (EPA Reg. No. 62719

- 220) end use products. Moreover, a b ridg ing

study was submitted to compare residues in tart cherries after application of the 50% WP (EPA

Reg. No. 62719

- 221) and 75% WG end use products. T he use directions described in the label

of the formulations used in these studies are described in Table 3

.

Table 3 . Summary of Directions for Use of Chlorpyrifos

.

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

Limita tions

Tart Cherries

Foliar Spray 50% W P 2 3 6 14

Dormant/Delay

ed Dormant

Foliar Spray 75% WG 2 1 2 NA

Trunk Spray

and/or Preplant

Dip 75% WG 3 1 3 21

Cotton

Broadcast

Foliar Spray 75% WG 1 3 3 14 Do not allow meat or

d a i ry animals to graze in

tr eated areas. Do not

feed gin trash or treated

forage to meat or diary

animals. 1 Lorsban 4E 1 3 3 14Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 7 of 37 Table 3 . Summary of Directions for Use of Chlorpyrifos

.

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

Limita tions

Cereal Grains (For Aspirated Grain Fractions)

Sorghum

Postemergence

broadcast

foliar spray 75% WG 1 3 1.5 30 or 60 PHI is either 30

- day or

60

- day if application

rate is below or above

0.5 lb ai/A, respectively. Lorsban 4E 1 3 1.5 30 or 60

Soybean

Postemergence

broadcast

foliar spray 75% WG 1 3 3 28 Do not allow meat or

dairy animals to graze in

treated areas or

otherwise feed treated

soybean for age, hay, and

straw to these. Lorsban 4E 1 3 3 28

Wheat

Foliar Spray Lorsban 4E 0.5 2 1 14 (forage

and hay)

or 28

(grain and

straw) Do not allow meat or

dairy animals to graze or

otherwise feed on

treated forage within 14

days of application.

1 Feeding restrictions to livestock can be eliminated from the corresponding labels.

Cherries

- Chlorpyrifos formulated as either a 75% WDG (water dispersible granule) or 50% WP

(wettable powder) was applied five times as broadcast foliar applications at 1.5

- 1.6 l b

ai/A/application at RTIs of 10

- 14 days, for a total of 7.4

- 7.6 lb ai/A/season and a 14

- day PHI.

Applications were made using ground equipment and did not include any spray adjuv ant. This

use pattern differs from that included in the label of the 75% WDG and 50% WP end

- use

products, see T able 3 . Only postemergence foliar applications are included in the label of the

50% WP end

- use product. Moreover, the maximum single and seasonal application rates

included in the label are below those used in the crop field trials.

Cotton

- Chlorpyrifos formulated as a 75% WDG and a 4 lb/gal EC was applied to cotton as

broadcast foliar applications at ~1.0 lb ai/A/application, at RTIs of 10

- 14 days, for a total of 3.0

- 3.1 lb ai/A/season, and a 14

- day PHI. All applicat ions were made using ground equipment and

no adjuvants were added to the spray mixture. This corresponds to the use pattern described in

the label of the 75% WDG and 4 lb/gal EC end

- use products.

Cereal Grains

– Chlorpyrifos was applied as 4 lb/gal EC an d 75 % WDG formulations to

soybean and sorghum, and only the EC formulation to wheat. Broadcast foliar applications were

performed to the three crops. For soybean, 3 applications at rates totaling 3.0 lb ai/A/season (1x

rate); for sorghum 2 applications at rates totaling 1.5 lb ai/A/season (1x rate); and for wheat 2

applications at rates totaling 1.0 lb ai/A/season (1x rate) were used. The samples were harvested

at 27

- 29 days after the last treatment (DAT). These use patterns correspond to those describ ed in

the label of the 75% WDG and 4 lb/gal EC end

- use products with the exception that wheatChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 8 of 37 forage and hay can be ha rvested 14 days after treatment

.

Conclusions

. For tart cherries, the label of the 50% WP end use product contains instructions for

folia r application with a maximum seasonal rate of 6 lb ai/A and 14

- day PHI. On the other hand,

the current label for the 75% WDG end use product contain instructions for dormant/delay

dormant and trunk spray applications to tart cherries with a maximum season al rate of 2 lb ai/A

and 3 lb ai/A, respectively. These use patterns correspond to a lower maximum seasonal

application rate than that used in the study submitted for tart cherries. For cotton, sorghum,

soybean and wheat, t he use pattern in the study sub mitted is equivalent to that described in the

label of the 75% WDG and /or 4 lb/gal EC formulation.

860.1300 Nature of the Residue

– Plants and Livestock

D266564, S. Knizner , 20/June/2000

Plants

- The qualitative nature of the residue in plants is ade quately understood based on

acceptable metabolism studies with cereal grain (corn) and root and tuber vegetable (sugar

beets). The terminal residue of concern in/on plants is chlorpyrifos. The requirement of the

metabolism study in a third crop (legume v egetable) was waived. Earlier metabolism studies

with apples, dry beans, and soybeans, although not completely acceptable, provide supplemental

data to elucidate the metabolism of chlorpyrifos in plants.

Livestock

- The qualitative nature of residue in animals is adequately understood based on

acceptable poultry and ruminant metabolism studies. The residue of concern in animals is

chlorpyrifos.

1 NA = Not Applicable

The database for determining residues of concern for chlorpyrifos is considered adequate and

new studies haven’t been requested or submitted. However, the chlorpyrifos o xon has been

characterized as having higher toxicity than chlorpyrifos. It is considered a residue of concern in

drinking water based on it toxicity and because the oxon has been detected in environmental

samples including surface water, precipitation, and air.

The chlorpyrifos oxon ha s not been identified as a residue of concern in plants. Previous

metabolism studies in corn and sugar beet commodities (with PHIs longer than 38 days) Table 4

. Summary of Metabolites and Degradates to be included in the Risk Assessment and Tolerance

Expres sion

Matrix Residues included in Risk

Assessment Residues included in

Tolerance Expression

Plants Primary Crop Chlorpyrifos parent only Chlorpyrifos parent only

Rotational Crop NA 1 NA

Livestock Ruminant Chlorpyrifos parent only Chlorpyrifos parent onl y

Poultry Chlorpyrifos parent only Chlorpyrifos parent onlyChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 9 of 37 characterize TCP a s the major metabolite (D198040, S. Kniz n er, 15/Sep/19 94) . Other minor

metabolites , hydrolyzable to TCP, were also identified. However, detection of the oxon is not

reported. Two peer

- reviewed articles report formation of the oxon in plants. A study of

dislodgeable r esidues on citrus leaf report presence of the oxon after treatment with Lorsban

(Iwata et. al., J. Agric. Food Chem. ). The chlorpyrifos oxon was not sought in the fruit,

h owever, no r esidues f

r o m parent chlorpyrifos were reported above the limit of detection ( 0.03

ppm ) in the edible portion of the citrus fruit. Another study reports the presence of the

chlorpyrifos oxon in tomatoes and green beans grown in greenhouses treated with Dursban at a

rate of 1.5 lb ai/A (Martinez et. al., J. Agric. Food Chem. )

. The reported LOD was 0.012 ppm.

The o xon appears in both crops only during the first 5 days after application with a maximum

concentration of 0.21 ppm in green beans and 0.19 ppm in tomatoes at the 3 rd day. In terms of

the registered uses of chlorpyrifos, with the exception of asparagus ( 1

- d ay PHI ) and alfalfa (4

- day PHI in one of the 10 registered products )

, the shortest PHI established in the labels is 6 days.

However, most crops have PHIs longer than 14

- days. Based on the short life of the chlorpyrifos

oxon is unlikely that it may be pre sent at significant concentration in the edible portions of the

crops. Indeed, during 2008 and 2009 the United States Department of Agriculture monitoring

program searched for the chlorpyrifos oxon in 17 commodities (including asparagus) for a total

of 11 041 samples being analyzed. Only o ne sample of potato showed presence of the oxon at

trace levels, 0.003 ppm (the LOD was 0.0 02 )

. However, there are no registered uses of

chlorpyrifos on potato in the U.S.

In terms of exposure of livestock to feed commo dities containing the oxon, toxicity studies show

that the oxon is unstable and is rapidly deactivated through hydrolytic cleavage by a process

call ed dearylation releasing TCP

. Therefore, it may be expected that low levels of the oxon are

metabolized bef

ore human consumption of livestock commodities. Indeed, it presence in was

assessed in cattle and dairy cow feeding studies with unradiolabled material to preclude its

presence ( MRID 00095179 ) . These studies showed absence of the oxon at all feeding leve ls.

Conclusions

. Based o n the absence o f evidence indicating that the chlorpyrifos oxon would be

present in edible portions of the crops at periods longer than the registered PHI s , HED considers

that it is not a residue of concern at this time. Howev er, HED may reconsider this decision if

monitoring data or new studies raise concern about the presence of the oxon at significant levels

in plant or livestock commodities.

860.1340 Residue Analytical Methods

Data Collection Methods

46640901.der, 466 51201.der and 46651202.der

Tart Cherries

Cherry samples were analyzed for chlorpyrifos only , using two methods, a GC/MS method

(GRM 02.03) using negative

- ion chemical ionization and a newer HPLC/MS /MS method ( GRM

04.15 ) u sing electrospray as the interf as e . All samples were analyzed using Method GRM 02.03Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 10 of 37 and a subset of samples was also analyzed using GRM 04.15 in order to demonstrate the validity

of the newer HPLC/MS /MS method. Both methods were adequately validated in conjunction

with the analysis of field trial samples. In both methods, resides of chlorpyrifos are extracted

with acetone/water (80: 20) and centrifuged. For the GRM 02.03 method, the sample is

transferred to a C 18 solid

- phase extraction (SPE) column , eluted with acetonitrile/0.1 N HCl

, d iluted with 0.1 N HCl and extracted with isooctane containing 13 C 2 15 N

- chlorpyrifos as the

internal standard

. For the GRM 04.15 method, the internal standard is added first and then the

sample is cleaned up using an on

- line SPE column, methanol/ water (60:4 0) is used to wash the

column and then the sample is eluted with the mobile phase.

The above methods were validated in conjunction with the analysis of field trial samples using

control samples of cherries fortified with chlorpyrifos at 0.01 to 1.0 ppm. C oncur rent recoveries

of chlorpyrifos were 73

- 93% (87 ± 3%), from fortified cherries analyzed using method GRM

02.03, and recoveries of chlorpyrifos were 81

- 93% (87 ± 3%) from fortified cherries analyzed

using Method GRM 04.15 . The validated limit of quant itation (LOQ) is 0.01 ppm for both

methods and the limit of detection (LOD) is 0.003 ppm. Comparison of samples analyzed for

chlorpyrifos using the GC/MS and HPLC/MS methods indicated the two methods yielded similar

residue values, with an r 2 of 0.9891. A dequate sample calculations and example chromatograms

were provided

.

Aspirated Grain Fractions

The HPLC/MS /MS method (GRM 04.15) described above was used to determine chlorpyrifos

residues in/on grain and AGF are adequate for data collection. In conjunc tion with the analysis

of treated samples, the above method was validated using control samples of grain and AGF

fortified with chlorpyrifos at 0.01 and 1.0 ppm. Concurrent recoveries of chlorpyrifos averaged

83

- 92% with standard deviations of 1

- 6%. No va lues were outside the acceptable 70

- 120%

range. Apparent residues were <LOQ in all control samples. The validated method LOQ for

chlorpyrifos is 0.01 ppm, and the LOD is 0.003 ppm. Adequate sample calculations and

examp le chromatograms were provided.

C otton gin by

- products

Residues of ch lorpyrifos were determined in gin trash using a HPLC/MS /MS method (GRM

04.15). The method was adequately validated in conjunction with the field sample analyses.

Concurrent recoveries of chlorpyrifos were 91±5% from g in trash fortified at 0.01

- 200 ppm.

Apparent residues of chlorpyrifos were <LOQ in/on 3 controls and 0.02

- 0.12 ppm in/on 3 other

controls. The method limit of quantitation (LOQ) is 0.01 ppm, and the limit of detection (LOD)

is 0.003 ppm. Adequate sample s calculations and example chromatograms were provided.

Conclusions

. The residue analytical methods used for the analysis of samples in the studies

under consideration are adequate based on the method recoveries, precision and the range of

levels tested which included the LO Q, the current tolerance for tart cherries, the tolerance level

recommended for cotton gin byproducts and the residues observed in the samples used to

calculate the tolerance recommended for AGF

.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 11 of 37 Enforcement Methods

D266564, S. K nizner , 20/June/2000

The Pesticide A nalytical Manual (PAM) Volume II lists three methods (designated as Methods I,

II and VI) for the enforcement of tolerances of chlorpyrifos in plant commodities. These are

based on analysis of chlorpyrifos by Gas Liqui d Chromatography (GLC) with flame photometric

detection and a detection limit of 0.01 ppm. Three confirmatory procedures are listed as Method

A. For the enforcement of tolerances in livestock commodities, PAM Vol. II lists Method IV

which is based on the quantitation of chlorpyrifos by GLC with electron capture detection. The

detection limit is 0.01 ppm.

Conclusions

. The methods in the PAM Volume II are adequate to analyze the residue of concern

for tolerance enforcement purposes, chlorpyrifos only

. The limit of detection of these methods is

adequate to cover the lowest tolerance level included in the 40 CFR § 180.342 for detection of

chlorpyrifos only , 0.01 ppm.

860.1360 Multiresidue Methods

D266564, S. Knizner , 20/June/2000

The FDA PESTDATA dat abase dated 8/93 (PAM Vol. I, Appendix II) indicates that

chlorpyrifos is completely recovered (>80%) using FDA mu l tiresidue method protocols D

(Section 232.4) and E (Section 212.1/232.1, nonfatty matrices) and partially (50

- 80%) recovered

using multiresid ue method protocol E (Section 211.1/232.1, fatty matrices).

Conclusions

. The multiresidue methods in the PAM Volume I under protocol D and E are

adequate to analyze the residue of concern for enforcement purposes, chlorpyrifos only

.

860.1380 Storage Stability

D266564, S. Knizner , 20/June/2000

46640901.der, 46651201.der and 46651202.der

Storage stability studies in a variety of crops, process ed commodities and livestock commodities

have been submitted and considered adequate as established in the RE D. A summary of these

studies is presented in Table 5.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 12 of 37 TABLE 5. Summary of Storage Conditions for Chlorpyrifos

.

Matrix

(RAC) Storage

Temperature

(°C) Longest Storage

Duration from

Sampling to

Extraction Interval of Demonstrated Storage Stabili ty (months)

Cherr y Field: Ambient

Processor: Frozen

Analytical

Facility:

- 17±5 215 days

(7.2 months) Oil seeds: Residues of chlorpyrifos are stable in/on

almonds and almond hulls stored at

- 18 °C for 9

months and in/on walnuts stored at

- 18°C for 4 year s.

Non

- oily grains: Residues of chlorpyrifos are stable

in/on corn grain, forage, and fodder stored at

- 18 °C for

27 months, in/on sweet corn fodder stored at

- 18 ° C

for almost 3 years, and in/on sorghum grain, forage,

and fodder stored at

- 18 °C for 3 m onths.

Root and bulb crops: Residues of chlorpyrifos are

stable in/on sweet potatoes stored at

- 18 °C for 4

months in/on sugar beet roots stored at

- 18 ° C for

almost 4 years. and in/on onions stored at

- 23 °C for 15

months.

Fruits and fruiting vegetable s: Residues of chlorpyrifos

are stable in/on apples, apricots, cherries, peaches,

pears, and plums stored at

- 18 °C for 9 months, in/on

whole bananas and banana pulp and peel stored under

frozen storage conditions (temperature unspecified) for

3 months, in /on tomatoes stored at

- 18 °C up to 29

months, and in/on cherries stored at

- 23 °C for 15.6

months, and in/on whole oranges stored at

- 18 C for 6

months.

Low moisture content forage/hay: Residues of

chlorpyrifos are stable in/on fresh and spent mint hay

s tored under frozen storage conditions (temperature

unspecified) for 10 months and in/on alfalfa forage and

hay stored at

- 18 °C for 12 months.

Processed commodities: Residues of chlorpyrifos are

stable in orange peel and pulp stored at

- 18 ° C for 5

- 6

mon ths and in mint oil stored under frozen storage

conditions (temperature unspecified) for 10 months.

Animal commodities: Residues of chlorpyrifos are

stable in cattle tissues stored at

- 18 ° C for up to 41

months and in milk stored at

- 18 °C for 49 months. Cotton gin

by

- products 198 days

(6.6 months)

Grain and

AGF 244 days

(8.1 months)

The storage conditions and intervals of commodity samples used for tolerance establishment

(cotton gin by

- products and aspirated grain fractions) and reassessment ( tart cherries) are

supported by adequate storage stability data as follows:Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 13 of 37 - Cherry samples were stored frozen for up to 215 days prior to extraction for analysis.

Adequate storage stability data are available on cherries indicatin g that chlorpyrifos is

stable at ≤

- 20 °C in cherries for at least 15.6 months. These data will support the frozen

storage durations in the current cherry field trials.

- Gin trash samples were stored frozen for up to 198 days prior to extraction for analysis.

Adequate storage stability data are available indicating that chlorpyrifos is stable at ≤

- 18

°C in/on alfalfa forage and hay for at least 12 months. These data will support the

frozen storage duration in the current cotton field trials.

- Grain and AGF were stored frozen for up to 244 days prior to extraction for analysis.

Adequate storage stability data are available that indicate that residues of chlorpyrifos

are stable in corn grain for up to 27 months. These data will support the frozen storage

duration in the current field trials.

Conclusions

. There are adequate storage stability data available in a wide variety of crops which

can be applied or translated to validate sample storage conditions and durations of samples of ta rt

cherries, cotton and aspirated grain fractions used in the studies being considered. In addition, as

described in Table 5 and discussed in the RED, acceptable storage stability studies have been

conducted on representative oil seeds, non

- oily grains, r oot crops, fruits and fruiting vegetables,

low moisture content forage and hay, selected processed food/feed commodities, and in animal

tissues and milk.

860.1400 Water, Fish, and Irrigated Crops

D326647, D. Drew, 07/Dec/2009

A petition to establis h a tolerance in catfish was received based on the detection of chlorpyrifos

in farm

- raised Mississippi catfish as part of the Food and Drug Administration (FDA)

aquaculture monitoring program. After considering the residue and usage data

, HED contended

t hat the likely source of residues in catfish may not be from catfish feed but from off

- target drift

from a nearby crop; therefore, a tolerance was not recommended. In 1994, the Mississippi

Department of Agriculture and Commerce took action to reduce off

- t arget drift by prohibiting

the use of chlorpyrifos on cotton and limiting it s use to ground applications only for many other

crops. No detections of chlorpyrifos were reported between 2002 and 2005 by the Mississippi

State Chemical Laboratory monitoring p rogram. Currently, the USDA PDP data for 2008 and

2009 shows 0.5% to 0.7% of detects in the USA ranging from 1 ppb to 2.8 ppb while the data for

imported catfish shows 0% to 50% of detects ranging from ND to 38.2 ppb.

Conclusions

. EPA should inform t h e FDA about these illegal residues of chlorpyrifos detected

in several crops and catfish for them to take the appropriate action.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 14 of 37 860.1460 Food Handling

D266564, S. Knizner , 20/June/2000

The RED established that reregistration requirements for magnitude of the residue of

chlorpyrifos in food

- handling establishments (FHE) a re fulfilled. Results of submitted studies in

FHE indicate that no detectable residues (<0.0 1 to <0.025 ppm) are likely to occur in food items.

Currently, the 40 CFR 180.342 l imits FHE uses of chlorpyrifos to spot and/or crack and crevice

treatment. In addition, a tolerance of 0.1 ppm is established for residues of chlorpyrifos only , in

or on food commodities in FHE with the exception of those commodities covered by a higher

t olerance as a result of use on growing crops. At this time it appears that we have two

chlorpyrifos containing products labeled for FHE use. However

, BEAD reviewed more recent

proprietary data (2008) for pesticide use in food handling establishments and found that chlorpyrifos

use was not reported . H owever, they report a 2% use to provide an upper bound estimate of

chlorpyrifos use in FHEs.

Conclusions

. The r equirements for chlorpyrifos formulations for use in FHE were previously

assessed and considere d fulfilled according to the current guidelines, OPPTS 860.1460. Since

then new end use products for use in FHE haven’t been registered.

860.1480 Meat, Milk, Poultry, and Eggs

D266564, S. Knizner , 20/June/2000

MRID 00095179

There are presently no regi stered direct application uses of chlorpyrifos on livestock animals

except for ear tag treatment of cattle. As established in the 2000 RED, residues in whole milk

and fat resulting from ear tag use should not be a significant fraction of the residues resul ting

from intake of animal feeds containing chlorpyrifos. Uses of chlorpyrifos may result in residues

in several feed commodities. Cattle , swine, dairy cow and poultry feeding studies were

previously evaluated and found adequate to satisfy feeding study requirements (D266564, S.

Knizner , 20/June/2000; and MRID 00095179)

. A conservative reassessment of the dietary

burden was performed to consider residues at tolerance level in feedstock commodities (aspirated

grain fractions and cotton gin by

- products) in cluded in this assessment and to use the most

current version of Table 1 (OPPTS Test Guidelines 860.1000) released on June 2008. The

dietary burden estimated is considered a worst case scenario as t he percent of crop treated is not

included in the calcula tions

.

For beef, a dietary burden of 6.56 ppm was calculated , see Table 6

. In the cattle feeding study

chlorpyrifos was administered daily to groups of three animals for 30 days at dry weight ba sis

levels of 0, 3 ppm (0. 5 x) , 10 ppm ( 1. 5 x) , 30 ppm ( 4.6 x) or 100 ppm (1 5 x)

. The dosing levels in

the feeding study are appropriate to cover the beef dietary burden estimated based on current

feeding practices

. This study is also appropriate in terms of the tolerances established for cattle

fat (0.3 ppm), cattle meat (0.05 ppm) and cattle meat byproducts (0.05 ppm) since residues ofChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 15 of 37 chlorpyrifos observed after dosing at the 10 ppm ( 1

. 5 x ) level were not detected (ND) in kidney,

ND

- 0.03 ppm in liver, ND

- 0.02 ppm in muscle, and 0.07

- 0.16 ppm in fat. Therefore, the

t olerances previously established cover possible residues in beef commodities.

For dairy cattle, a dietary burden of 15.27 ppm was calculated

. To as sess residues in milk

samples groups of three dairy cows were dosed on a daily bas i s for a period of two weeks with

chlorpyrifos at levels of 0.3 ppm (0. 02 x) , 1 ppm (0. 7 x) , 3 ppm ( 0.2 x ) , 10 ppm (0.7 x) or 30 ppm

(2 x)

. The dosing levels in the feeding study are appropriate to cover the dairy cattle dietary

burden estimated based on current feeding practices. This study is also appropriate in terms of

the tolerances estab lished for milk fat (0.25 ppm) since residues of chlorpyrifo s observed after

dosing at the 30 ppm (2 x) level were < 0.02 ppm in whole milk and < 0.15 ppm in cream. The

tolerance for milk fat co vers residues in whole milk which previously had a tolerance of 0.01

ppm. Therefore, the current tolerance for milk fat covers possible residues in milk commodities.

For swine, a dietary burden of 1.16 ppm was calculated. In the swine feeding study ch lorpyrifos

was administered to groups of 3 animals on a daily basis for a period of 30 days at levels of 0

ppm , 1 ppm ( 0.9 x) , 3 ppm (2.6 x) or 10 ppm (8.6 x)

. The dosing levels in the feeding study are

appropriate to cover the swine dietary burden estimated based on current feeding practices. This

study is also appropriate in terms of the tolerances established for hog fat (0.2 ppm), hog meat

(0.05 ppm), hog meat byproducts (0.05 ppm) since residues of chlorpyrifos were not detected in

swine muscle, liver a nd kidney at levels up to 3 ppm (2.6 x) and were < 0.04 ppm in swine fat at a

dose of 3 ppm (2 .6 x). Therefore, the tolerances previously established cover possible residues in

hog commodities.

For p oultry, a dietary burden of 1.09 ppm was calculated. Th e poultry feeding study was

performed by dosing groups of 36 birds for 30 days at levels of 0 ppm , 0.3 ppm (0.3x) , 1 ppm

(0.9x)

, 3 ppm (2.8 x) or 10 ppm (9.2 x) of chlorpyrifos . Twenty four birds from each group were

slaughtered and their muscle, liver, kid ney and peritoneal fat analyzed for residues of

chlorpyrifos while the remaining twelve birds were dosed for additional 15 days and their whole

eggs analyzed. The dosing levels in the feeding study are appropriate to cover the poultry

dietary burden estim ated based on current feeding practices. This study is also appropriate in

terms of the tolerances established for poultry fat (0.1 ppm), poultry meat (0.1 ppm), poultry

meat byproducts (0.1 ppm), and eggs (0.01 ppm) since residues were not detected in wh ole eggs,

poultry muscle, poultry liver, and poultry kidney at all dose levels and were <0.02 ppm in fat at a

dose of 3 ppm ( 2.8 x)

. Therefore, the tolerances previously established cover possible residues in

poultry commodities.

Based on concerns with t he higher toxicity of chlorpyrifos oxon it’s important to mention that it

was assessed in the cattle (limit of sensitivity of 0.05 ppm) and dairy cow (limit of sensitivity of

0.01 ppm) feeding studies to preclude its presence

. These studies showed absence of the oxon at

all feeding levels.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 16 of 37 Table 6 . Calculation of maximum dietary burden for Chlorpyrifos

.

Feed Commodity

(Classification) Tolerance (ppm) % Dry Matter 1 % of Diet Burden (ppm) 2

Beef Cattle

Aspirated Grain Fractions (CC) 22 85 5 1.29

Field Corn Grain (CC) 0.05 88 25 0.0 2

Beet Sugar Molasses (CC) 15 75 10 2.00

Sorghum, grain, grain (CC) 0.5 86 40 0.23

Field Corn Forage (R) 8 40 1 5 3 .00

Soybean Meal (PC) 0.3 92 5 0.02

TOTAL 100 6.56

D a i ry Cattle

Beet Sugar Molasses (CC) 1 5 75 10 2.00

Sorghum, grain, grain (CC) 0.5 86 25 0.15

Sweet Corn, cannery waste (CC) 8 30 10 2.67

Field Corn Forage (R) 8 40 45 9.00

Alfalfa, meal (PC) 13 89 10 1.46

TOTAL 100 15.27

Poultry

Wheat Grain (CC) 0.5 NA 75 0.375

Soybean Seed (PC) 0.3 NA 20 0.060

Alfalfa Meal (PC) 13 NA 5 0.650

TOTAL 100 1.09

Swine

Sorghum, grain, grain (CC) 0.5 NA 80 0.400

Wheat, milled by products (CC) 3 1.5 NA 5 0.075

Alfalfa Meal (PC) 13 NA 5 0.650

Soybean Seed (PC) 0.3 NA 10 0.030

TOTAL 100 1. 16

1 As per R evised Table 1 (OPPTS Guideline 860.1000).

2 Burden = [anticipated residue % DM] X % diet.

3 Tolerance recommended for milli ng fractions excluding flour (pg 75, 2000 RED)

4 Tolerances in bold correspond to estimated residue based on translation o f tolerances from similar commodities;

from alfalfa hay to alfalfa meal, from soybean seed to soybean meal, and from sweet corn forage to sweet corn

cannery waste.

5 Aspirated grain fractions provided a higher dietary bu r den to beef cattle but based on availability of feedstock it

can’t be considered simultaneously with cotton gin byproducts, see Table 1 of 860.1000.

Conclusions

. The calculated dietary burdens are covered by the dosing levels used in the feeding

studies at a 1x level and two exagger ated levels 3x and about 10x for beef cattle, poultry and

swine while for dairy cattle it covers the dosing levels up to 2x. Based on the residues observed

in the feeding study of cattle beef, dairy cow, s wine and poultry at the 1x level or higher

, HED

co ncludes that the possible residues observed on livestock commodities (feed with feedstock that

may contain residues resulting from legal applications ) are covered by the current tolerances

established in the 40 CFR 180.342

.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 17 of 37 860.1500 Crop Field Trial s

D326647, D. Drew, 7/Dec/2009

D266564, S. Knizner , 20/Jun /2000

46651201.der and 46651202.der

The 2009 scoping document presents a summary of the status of the residue chemistry database

after the 2000 RED and the mitigation measures addressed in the 200 2 Interim Reregistration

Eligibility Decision ( IRED ) . Additional magnitude of the residue data were required in the RED

for corn fodder and forage, cotton gin byproducts, clover and grasses grown for seed , aspirated

grain fractions of sorghum, soybean and wheat, and cherries. Since the 2000 assessment some

new crop field trial studies have been submitted for cotton gin byproducts, tart cherries, aspirated

grain fractions for soybean, sorghum and wheat, and grass forage and hay as part of a data call in

rel ated to the RED

. There has also been new petitions/label amendments submitted for Group 17

alfalfa, alfalfa mixed stands and grass grown for hay or pasture, and barley. In addition, the

IRED issued in February 2002 included mitigation measures addressing additional risks not

included in the RED. Risk mitigation measures related to current uses included restricting use on

apples to pre

- bloom and dormant application resulting in a reduced tolerance, and the tolerance

for grape was reduced to reflect domestic dormant application only

. The following is a

discussion of the status of the residue chemistry deficiencies and actions related to mitigation

measures

.

Apart from deficiencies listed in the scoping document, new studies were submitted by the

petitioner for label amendments related to sweet potato uses and a bridging study for a

microencapsulated formulation. The studies for sweet potato (47122001 and 46995201) follow a

request to reduce the labeled PHI (125 days) in the Lorsban 4E end use product. The petition for

the review of these studies was cancelled in 29/June/2009 . In addition, a bridging study to

support the registration of a microencapsulated formulation was submitted but found inadequate

(D 373650, I. Negron, 23/Nov/ 2010 ); therefore, the regi stration of the new formulation was not

granted. However, during this study Lorsban 4E end use product was applied as a foliar spray to

lemon with a single application at a rate of 6 lb ai/A and the crop was harvested at a 35

- day PHI.

No adjuvant was add ed to the spray mixture. The maximum residue observed in that study was

at a concentration of 1.41 ppm which is over the current tolerance for citrus fruit (CG 10), 1.0

ppm. The label of the Lorsban 4E (44.9% chlorpyrifos) end use products allows a maxim um

application rate of 6.4 lb ai/A, addition of petroleum oil or citrus oil to the spray mixture and a

PHI of 35

- days (when the application rate is above 3.75 lb ai/A). Under these conditions

residues over tolerance may occur; therefore, HED recommends a reassessment of the tolerance

for citrus fruit using lemon (it’s the citrus that shows higher residues in the bridging study) as the

representative commodity. Indeed, the studies used to establish the tolerance for citrus fruit were

performed with oranges and grapefruit only

. Moreover

, these previous studies showed that

higher residues are observed after using low application volumes; therefore, the formulation shall

be applied with the lowest volume recommended in the label. Since this reassessment is f orChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 18 of 37 postemergence foliar applications its necessary to include the 75% WDG as a side

- by

- side trial

with Lorsban 4E

. Three plots are recommended per field trial: (1) o ne application of Lorsban 4E

at the maximum single rate and 35

- day PHI, (2) one applicatio n of 75% WDG at the maximum

single rate and 35

- day PHI , and (3) control

. This would not reflect the maximum seasonal rate of

7.5 lb ai/A but may yield higher residues than two applications at a lower rate since a RTI of 30

days is established in the label

.

As part of the mitigation efforts the tolerance for apple was reduced to 0.01 ppm to reflect pre

bloom and dormant applications only . In September 2007 a petition from IR

- 4 was received to

amend the label of Lorsban 4E to include trunk treatment on appl e trees (D310433 and D336586,

M. Doherty, 18 /Sep/ 2007)

. The residue data showed residues below 0.01 ppm in all control and

treated samples; therefore, HED supported the label revision and tree trunk applications are

currently allowed.

Currently, no petit ions for the establishment of new tolerances for chlorpyrifos are pending.

Moreover, the petitions 7F7248 (alfalfa, alfalfa mixed stands, grass grown for hay or pasture),

3F4188 (barley grain and forage), and 3H5662 (barley, milling fractions) identified in the 2009

scoping document were withdrawn in 07 /May /2009. A magnitude of the residue study to

establish a tolerance for wheat hay was required in the RED and has not been received. Studies

for clover were not received as part of a Special Local Need act ion identified in the RED ;

therefore, tolerances for clover were not established in the CFR.

For corn, label restrictions prohibiting feeding of forage and stover to meat or dairy animals are

not considered practical. Two SLN la bels were identified in the RED as containing these

restrictions, SLN DE930004 and FL 940003 ; however, the latter was cancelled. A revision to

Section 3 labels for corn was performed by HED to specify PHIs and resolve other discrepancies

(D338439, C. Swartz, 28 / March / 2007). Lab el amendments were recommended to reflect the

crop field trial use pattern. Moreover, pre

- foraging intervals and pre

- grazing intervals may be

removed from the labels since tolerances for residues in corn forage and stover are included in

the CFR. Based o n this the SLN label DE930004 and all the labels for chlorpyrifos products

may be revised to eliminate feeding restrictions.

The n ew crop field trial data submitted include m agnitude of the residue or processing studies for

sweet potatoes, grass forage and hay, cotton gin byproducts, tart cherries, and aspirated grain

fractions (AGF) of soybean, sorghum and wheat. The studies for grass forage and hay were

withdrawn with petition 7F7248 and no tolerances for these commodities are currently included

in th e CFR. Studies for cotton gin byproducts and tart cherries were reviewed and a summary is

included in this section

. Residue studies for cotton gin by products were requested in the RED

since feeding restrictions established in the label are not considere d practical. For tart cherries,

the registrant committed to perform residue studies to show similarity between a water

dissolvable granule (WDG) and the EC formulation. Chlorpyrifos and TCP residues were

determined in the magnitude of residue studies for tart cherries, cotton gin by

- products and

aspirated grain fractions. However, since TCP was excluded as a residue of concern the

following discussion will be limited to chlorpyrifos.

Tart CherriesChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 19 of 37 The number and geographic location of the tart cherry field trials are adequate. A total of 8 field

trials conducted on tart cherries in 2004, with each field site consisting of a control plot and four

treated plots using chlorpyrifos formulated as either a 75% WDG or 50% WP and applied as

either concentrate d sprays (43

- 54 gal/A) or dilute sprays (192

- 219 gal/A). In each test,

chlorpyrifos was applied five times as broadcast foliar applications at 1.5

- 1.6 lb ai/A/application

at RTIs of 10

- 14 days, for a total of 7.4

- 7.6 lb ai/A/season. Applications were mad e using

ground equipment and did not include any spray adjuvant. A single control and duplicate treated

samples of cherries were harvested from each site at 14 DAT, and at 0, 7, 14 and 21 DAT from

the two concentrated spray tests at one location.

At 14 D AT, residues of chlorpyrifos in/on cherries treated with the 75% WDG were 0.14

- 1.70

ppm for the concentrated sprays and 0.01

- 1.12 ppm for the dilute sprays. Residues of

chlorpyrifos in/on tart cherries treated with the 50% WP were <0.01

- 0.41 ppm for the

c oncentrated sprays and <0.01

- 0.25 ppm for the dilute sprays. Average chlorpyrifos residues

were 0.48 and 0.39 ppm, respectively, from the concentrate and dilute sprays of the 75% WDG,

and 0.12 and 0.11 ppm, respectively, from the concentrate a nd dilute sp rays of the 50% WP

. When data are pooled for the two application volumes, average chlorpyrifos residues are 0.43

ppm for the 75% WDG and 0.11 ppm for the 50% WP, see Table 7 . Residue decline data

indicate residues of chlorpyrifos declined in the 21 days f ollowing application for concentrated

applications of both the 75% WDG and 50% WP formulations.

The data show an insignificant difference in residue levels between the two application volumes.

Residues were notably higher in the tests using the 75% WDG co mpare d to the 50% WP. A

tolerance of 2.0 ppm may be recommended based on the analysis of the 75%WDG formulation

by using the OECD calculator. However, the current label for the 75% WDG end use product

contain s instructions for dormant/delay dormant and t runk spray applications with a maximum

seasonal rate of 2 lb ai/A and 3 lb ai/A, respectively

. These use pattern s are not expected to

result in residues at the levels observed in the current study after foliar application with a

maximum rate of 7.5 lb ai/ A. The label of the 50% WP end use product contains instructions for

foliar application with a maximum seasonal rate of 6 lb ai/A and a 14

- day PHI. This use pattern

is covered by the current study which show s a maximum residue of 0.41 ppm which is covere d

by the current tolerance for tart cherries, 1.0 ppm. Since the data for tart cherries treated with a

foliar spray of the 75% WDG formulation showed residues above tolerance, HED recommends

to maintain only the dormant/delay dorman t and trunk spray appli cations o n the label of the 75%

WDG end use product. The use pattern in the label of the 50% WP formulation is considered

adequate.

Table 7

. Summary of Residue Data from the Crop Field Trials with Chlorpyrifos (WDG or WP).

Commodity Total Applic.

Rate

(lb ai/A) PHI

(days) End

- use

Product Residue Levels (ppm) 1

n Mean Std. Dev. HAFT 2 Min. Max.

Tart Cherry (proposed use = 6 lb ai/A total application rate, 14

- day PHI )

Tart Cherry 7.4

- 7.6 14 75% WDG 32 0.43 0.38 1.56 0.01 1.70

50% WP 32 0.11 0.1 0 0.36 <0.01 0.41

1 The LOQ for Chlorpyrifos residues in/on cherry is 0.01 ppm. The LOD is 0.003 ppm. For calculation of the median, mean,

and standard deviation, 1⁄2LOQ was used for samples with residues <LOQ.

2 HAFT = Highest Average Field Trial.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 20 of 37 Cot ton gin by

- products

The number and geographic location of the cotton field trials are adequate since for cotton gin

byproducts three trials per each harvest method are required

. The field trials were conducted in

four locations during 2004 in Regions 6, 8, and 10. Side

- by

- side tests were conducted at each

field site using chlorpyrifos formulated as a 75% WDG and a 4 lb/gal EC. Each formulation was

applied to cotton at each site as three broadcast foliar applications at ~1.0 lb ai/A/application, at

RTIs of 10

- 14 days, for a total of 3.0

- 3.1 lb ai/A/season. All applications were made using

ground equipment at 11

- 17 gal/A, and no adjuvants were added to the spray mixture. A single

control and duplicate treated samples of cotton were machine harvested from each test at 14

DAT. The cotton was harvested using either a mechanical picker or stripper at two sites, and

using both pickers and strippers at the remaining two sites, for a total of 3 tests each being

harvested by mechanical pickers and strippers for each formulation. The cotton was then ginned

to yield samples of gin trash.

Following broadcast applications of chlorpyrifos (WDG or EC) at rates totaling 3.0

- 3.1 lb

ai/A/season, residue levels in gin trash were similar for the two types of formulations, but were

substantially higher in gin trash from cotton harvested with a picker than cotton harvested with a

stripper. At 1 4 DAT, residues of chlorpyrifos were 9.2

- 76.5 ppm in/on 12 samples of gin trash

from picker

- harvested cotton and 0.9

- 6.9 ppm in/on 1 2 samples of gin trash from stripper

harvested cotton (Table 8 ). Average residues were 33.4 and 2.9 ppm, respectively, for gin trash

from picker and s tripper harvested cotton . A residue decline study was not conducted.

The use pattern in the study submi tted is consider adequate as it is equivalent to that described in

the label of the 75% WDG and 4 lb/gal EC formulation. The data obtained with the stripper is

considered to set the tolerance for cotton gin byproducts since the cotton harvested with the

s tripper is the one used as a feed item. A tolerance estimate of 15 ppm is recommended by the

OECD calculator, see appendix 1

.

Table 8

. Summary of Residues from the Crop Field Trials with Chlorpyrifos (WDG or EC).

Commodity Total Applic.

Rate

(lb ai/A) Harvest

Method PHI

(days) Residue Levels (ppm) 1

n Mean Std. Dev. HAFT 2 Min. Max.

Cotton (proposed use = 3 lb ai/A total application rate, 14

- day PHI )

Gin Trash 3.0

- 3.1 Picker 14 12 33.4 25.5 66.7 9.2 76.5

Stripper 14 12 2.9 2.0 5.9 0.9 6.9

1 The LOQ for Chlorpyrifos is 0.01 ppm; and the LOD is 0.003 ppm.

2 HAFT = Highest Average Field Trial.

Conclusions

. Based on the residues over tolerance observed after application of Lorsban 4E to

lemon, HED recommends a reassessment of the tolerance for citrus fruit using lemon as the

representative commodity. Magnitude of residue studies to establish a tolerance for wheat hay

are required.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 21 of 37 The number and location of field trials for tart cherries and cotton comply with the requirements

of OPPTS 860 .1500 guideline. The data are adequate to establish a tolerance of 15 ppm for

cotton gin by products and to keep the current tolerance for tart cherries under the condition that

only dormant/delayed dormant and trunk spray applications remain in the label of the 75% WDG

end use product

. The studies with tart cherries showed that residues decline with increase in

DAT ; therefore, at intervals longer tha n the PHI residues are not expected to be higher than the

tolerance level established for tart cherries

. 860.1520 Processed Food and Feed

D266564, S. Knizner , 20/June/2000

46640901.der

As established in the 2000 RED, acceptable processing studies have been submitted and

evaluated for apples, citrus, corn, cottonseed, fig, grapes, mint, peanuts, plums, soybe ans, sugar

beets, sugarcane, sunflowers, tomatoes, and wheat. The requirements for processing data on

alfalfa meal were waived because residue data indicated that levels of chlorpyrifos per se were

not likely to exceed the establish ed tolerance in alfalfa hay following tests conducted according

to registered uses.

According to the revised version of Table 1 OPPTS 860.1000 several processing studies are

required to establish a tolerance for feed items that correspond to RACs treated with

chlorpyrifos. I n addition, other processing studies are required for processed food commodities

based on the same guideline. Tolerances are required for wheat milled byproducts and wheat

hay. A tolerance was previously established for wheat milling fractions excluding flour as 1.5

ppm. This tolerance should be reestablished as the tolerance for wheat milled byproducts. For

corn milled byproducts a tolerance of 0.1 ppm was previously recommended based on

concentration factors from 1.25x in grits to 2x in flour (D188151 , S. Knizner, 20/Aug/1993).

This tolerance should be established based on the importance of corn milled byproducts as a feed

commodity based on the revised version of Table 1. For cotton, processing studies are required

to establish tolerances in cotton meal, cotton hulls and refined oil. Similarly, f or soybean,

processing studies are required to establish tolerances in soybean meal, hulls and refined oil.

Two processing stud ies were received as part of the current action

. A non

- guideline cooking

study has been submitted to calculate processing factors for use in the dietary assessment (MRID

45619801). Further discussion of this study is included in the dietary assessment supporting the

current risk assessment (D 388166, D. Soderberg, in process )

. The other “ processing study ” is

for the establishment of a tolerance for aspirated grain fractions (AGF) of soybean, sorghum and

wheat. (Note: Although this study does provide a concentration factor for AGF, it is technically

not processing studies since AGF are considered to be a RAC.) This study was requested in the

RED since feeding restrictions established in the label are not considered practical.

Aspirated Grain Fractions

Three field trials were conducted during 2004 to generate samples of chlor pyrifos

- treated

soybean seed, sorghum grain, and wheat grain for use in generating samples of aspirated grain

fractions (AGF). In the soybean and sorghum trials, chlorpyrifos was applied in side

- by

- side

tests using the 4 lb/gal EC and 75 % WDG formulation s, and only the EC formulation was usedChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 22 of 37 in the wheat field trial. Chlorpyrifos was applied to soybeans as three broadcast foliar

applications at rates totaling 3.0 lb ai/A/season (1x rate), to sorghum as two broadcast foliar

application at rates totaling 1.5 lb ai/A/season (1x rate), and to wheat as two broadcast foliar

applications at rates totaling 1.0 lb ai/A/season (1x rate). Single bulk samples of control and

treated seeds/grain were harvested from each test at commercial maturity, 27

- 29 days after t he

last treatment (DAT). Following harvest, seeds and grain were processed into cleaned

grain/seed and AGF using simulated handling procedures.

Following three broadcast foliar applications of chlorpyrifos (4 lb/gal EC or 75% WDG) to

soybeans at rates totaling 3.0 lb ai/A/season (1x rate), residues of chlorpyrifos were 0.015 and

0.012 ppm from seeds harvested 29 DAT from plants treated with the WDG and EC

formulations, respectively. Residues in the respective AGF samples were 0.74 and 1.029 ppm,

for p rocessing factors of 49x and 86x (average 68x). F or sorghum, f ollowing two broadcast

foliar applications of chlorpyrifos (4 lb/gal EC or 75% WDG) at rates totaling 1.5 lb ai/A/season

(1x rate), residue of chlorpyrifos were 0.029 and 0.025 ppm in/on grain harvested 29 DAT from

plants treated with the WDG and EC formulations, respectively. Residues in the respective AGF

samples were 0.124 and 0.140 ppm, for processing factors of 4.3x and 5.6x (average 5x). F or

wheat, f ollowing two broadcast foliar applicat ions of chlorpyrifos (4 lb/gal EC) at rates totaling

1.0 lb ai/A/season (1x rate), residue of chlorpyrifos were 0.136 ppm in/on grain harvested 29

DAT, and 1.616 ppm in/on wheat AGF, for a processing factor of 11.9x. The use patterns in the

study submitte d are considered adequate as they are equivalent to those described on the labels

of the 75% WDG and 4 lb/gal EC formulations for foliar applications to soybean, sorghum and

wheat. A tolerance can be established as 22 ppm for chlorpyrifos residues in/on a spirated grain

fraction. This tolerance corresponds to the residue level estimated for soybean AGF which was

the highest in comparison to 2 ppm for sorghum AGF and 3 ppm for wheat AGF. The se residue

levels were estimated by multiplying the maximum residu e for the cereal grain (obtained from

the magnitude of residue studies used to set the tolerance) with the highest concentration factor

( obtained from the current study )

.

Table 9

. Residue Data from Grain and AGF Processing Study with Chlorpyrifos.

Cro p End

- Use

Product Commodity Total

Rate

(lb ai/A) PHI

(days) Residues (ppm) 1 Processing

Factor

Soybean 75 % WDG RAC Grain

3.01 29 0.015, 0.015

[0.015] 2 NA

Grain

(processor) 3 0.037, 0.022

[0.029] NA

Clean Grain 0.014, 0.014

[0.014] 0.93x

A GF 0.740 49x

4 lb/gal EC RAC Grain

3.00 29 0.011, 0.012

[0.012] NA

Grain

(processor) 0.011, 0.013

[0.012] NA

Clean Grain 0.010, (0.008)

[0.009] 0.75x

AGF 1.029 86x

Sorghum 75 % WDG RAC Grain 1.48 29 0.022, 0.035

[0.029] NAChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 23 of 37 Table 9

. Residue Data from Grain and AGF Processing Study with Chlorpyrifos.

Cro p End

- Use

Product Commodity Total

Rate

(lb ai/A) PHI

(days) Residues (ppm) 1 Processing

Factor

Clean Grai n 0.014, 0.011

[0.013] 0.45x

AGF 0.124 4.3x

4 lb/gal EC RAC Grain

1.48 29 0.028, 0.022

[0.025] NA

Clean Grain 0.018, ND

[0.14] 0.56x

AGF 0.140 5.6x

Wheat 4 lb/gal EC RAC Grain

1.00 27 0.138, 0.134

[0.136] NA

Clean Grain 0.127, 0.13 9

[0.133] 0.98x

AGF 1.616 11.9x

1 The LOQ for each analyte is 0.01 ppm. The LOD is 0.003 ppm.

2 Average residues used to calculate processing factors are in brackets.

3 Samples of soybean seeds were also collected at the processor.

4 ND = not detecta ble

, NA = not applicable

Conclusions

. According to OPPTS 860.1000 several processing studies are required to establish

a tolerance for food/feed items that correspond to RACs treated with chlorpyrifos. Processing

studies are required for: cotton meal, h ulls and refined oil; soybean me al, hulls and refined oil

. Moreover, the following tolerances can be reestablished to cover the processing studies required:

corn milled by products as 0.1 ppm; and wheat milled by products as 1.5 ppm.

S tudies required und er the OPPTS 860.150 0 guidelines for the aspirated grain fractions of

soybean, sorghum and wheat were performed . These studies are considered acceptable. A

single tolerance of 2 2 ppm is recommended for aspirated grain fractions which cover residues on

so ybean, sorghum and wheat.

860.1650 Submittal of Analytical Reference Standards

Analytical standards for the insecticide chlorpyrifos are to be kept available in the EPA National

Pesticide Standards Repository. These analytical reference standards mus t be replenished as

requested by the Repository. If requested, reference standards should be sent to the Analytical

Chemistry Laboratory located in Fort M eade to the attention of Theresa Cole at the following

address:

U.S. EPA

National Pesticide Standar ds Repository/ Analytical Chemistry Branch/OPP

701 Mapes Road

Fort George G. Meade, MD 20755

- 5350

Please note that mail will be returned if the entire extended zip code is not used when addressing

correspondence to the Repository.

860.1850 Confined A ccumulation in Rotational CropsChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 24 of 37 D266564, S. Knizner , 20/June/2000

Confined rotational crops studies with chlorpyrifos haven’t been required or submitted since the

RED. The studies discussed in the RED were based on the uptake of residues by lettuce, whe at

and carrot after application of radio labeled chlorpyrifos to the soil at a rate of 4.8 lb ai/A and a

plant back interval of 30 days. The TRR was above 0.01 ppm in all the rotational crops but the

highest concentration of chlorpyrifos was 0.009 ppm.

8 60.1900 Field Accumulation in Rotational Crops

D266564, S. Knizner , 20/June/2000

Field trial studies with rotational crop s h aven’t been submitted

. Based on the RED , a 30

- day

plant back interval for rotational crops is appropriate provided that all label s for chlorpyrifos

containing products limit application to 5 lb ai/A on those crops where rotation to another crops

could occur. Therefore, HED doesn’t require field rotational crop studies.

860.1550 Proposed Tolerances

Previously, t he Agency conclu ded that the TCP metabolite of chlorpyrifos is not of toxicological

concern and no longer needs to be regulated, and therefore, it was excluded from the tolerance

expression (D266564, S. Knizner , 20/June/2000). Currently, the tolerance levels include d unde r

the 40 CFR §180.342 are amended to reflect residues of chlorpyrifos per se

. However, as stated

in the RED, for some crops the field trial used to establish tolerances for some of these

commodities is based on combined residues of chlorpyrifos and TCP. I n the absence of adequate

data depicting residues of chlorpyrifos per se the established tolerances were maintained at the

existing levels. The registrant may submit additional data depicting residues of chlorpyrifos per

se if tolerance

- level reductions a re desired.

The established or proposed tolerances for chlorpyrifos are included in Table 10

. Chlorpyrifos

tolerances are establishe d under 40 CFR §180.342. On 27/May/ 2009 HED established interim

guidance on writing tolerance exp ressions for enforcement purposes. In order to add clarity to

the language used to establish the coverage of the tolerance expression and measurement of the

level of the residue in the RACs the text in the 40 CFR § 180.342 should read: “(a) General. (1)

Tolerances are established for residues of chlorpyrifos, including its metabolites and degradates,

in or on the commodities in the table below. Compliance with the tolerance levels specified

below is to be determined by measuring only chlorpyrifos ( O,O

- di ethyl O

- (3,5,6

- trichloro

- 2

- pyridyl) phosphorothioate).”

Table 10 . Tolerance Summary for Chlorpyrifos

Commodity Established/Proposed

Tolerance (ppm) Recommended

Tolerance (ppm) Comments

Correct Commodity Definition

Alfalfa, forage 3.0 3.0

Alfalfa, h ay 13 13

Almond 0.2 0.2Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 25 of 37 Table 10 . Tolerance Summary for Chlorpyrifos

Commodity Established/Proposed

Tolerance (ppm) Recommended

Tolerance (ppm) Comments

Correct Commodity Definition

Almond, hulls 12 12

Apple 0.01 0.01

Apple, wet pomace 0.02 0.02

Aspirated grain fractions NA 2 2

Banana 0.1 0.1

Beet, sugar, dried pulp 5.0 5.0

Beet, sugar, molasses 15 15

Beet, sugar, roots 1.0 1.0

Beet, sugar, t ops 8.0 8.0

Cattle, fat 0.3 0.3

Cattle, meat 0.05 0.05

Cattle, meat byproducts 0.05 0.05

Cherry, sweet 1.0 1.0

Cherry, tart 1.0 1 .0

Citrus, dried pulp 5.0 5.0

Citrus, oil 20 20

Corn, field, forage 8.0 8.0

Corn, field, grain 0.05 0.05

Corn, field, refined oil 0.25 0.25

Corn, field, stover 8.0 8.0

Corn, sweet, forage 8.0 8.0

Corn, sweet, kernel plus cob

with husk removed 0.05 0.05

Corn, sweet, stover 8.0 8.0

Cotton, undelinted seed 0.2 0.2

Cotton, gin by

- products NA 15

Cran berry 1.0 1.0

Cucumber 0.05 0.05

Egg 0.01 0.01

Fig 0.01 0.01

Fruit, citrus, group 10 1.0 1.0

Goat, fat 0.2 0.2

Goat, meat 0.05 0.05

Goat, meat byproducts 0.05 0.05

Hazelnut 0.2 0.2

Hog, fat 0.2 0.2

Hog, meat 0.05 0.05

Hog, meat byprod ucts 0.05 0.05

Horse, fat 0.25 0.25

Horse, meat 0.25 0.25

Horse, meat byproducts 0.25 0.25

Kiwifruit 2.0 2.0

Lettuce 1.0 Revoke 1

Milk, fat (Reflecting 0.01

ppm in whole milk) 0.25 0.25

Nectarine 0.05 0.05Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 26 of 37 Table 10 . Tolerance Summary for Chlorpyrifos

Commodity Established/Proposed

Tolerance (ppm) Recommended

Tolerance (ppm) Comments

Correct Commodity Definition

Onion, bulb 0.5 0.5

Peach 0.05 0. 05

Peanut 0.2 0.2

Peanut, refined oil 0.2 0.2

Pear 0.05 0.05

Pecan 0.2 0.2

Pepper 1.0 1.0

Peppermint, tops 0.8 0.8

Peppermint, oil 8.0 8.0

Plum, prune, fresh 0.05 0.05

Poultry, fat 0.1 0.1

Poultry, meat 0.1 0.1

Poultry, meat byproduct s 0.1 0.1

Pumpkin 0.05 0.05

Radish 2.0 2.0

Rutabaga 0.5 0.5

Sheep, fat 0.2 0.2

Sheep, meat 0.05 0.05

Sheep, meat byproducts 0.05 0.05

Spearmint, tops 0.8 0.8

Spearmint, oil 8.0 8.0

Sorghum, grain, forage 0.5 0.5

Sorghum, grain, grain 0. 5 0.5

Sorghum, grain, stover 2.0 2.0

Soybean, seed 0.3 0.3

Strawberry 0.2 0.2

Sunflower, seed 0.1 0.1

Sweet potato, roots 0.05 0.05

Turnip, roots 1.0 1.0

Turnip, tops 0.3 0.3

Vegetable, brassica, leafy,

group 5 1.0 1.0

Vegetable, legume, group 6

except soybean 0.05 0.05

Walnut 0.2 0.2

Wheat, forage 3.0 3.0

Wheat, grain 0.5 0.5

Wheat, straw 6.0 6.0

Tolerances with regional registrations

Asparagus 5.0 5.0

Grapes 0.01 0.01 Grape

1 The tolerance for lettuce will be revoked since no uses of chlorpyrifos on lettuce are included in the current labels.

Current US permanent tolerances for chlorpyrifos are listed in 40 CFR 180.342 are summarized

and compared to international Maximum Residue Limits (MRLs) in Table 11 . The CFR wasChlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 27 of 37 updat ed to revoke/modify tolerances and to change the tolerance definition as chlorpyrifos per

se . The Codex Alimentarius Commission and Canada have established MRLs for chlorpyrifos.

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

Codex MRLs are for residues of chlorpyrifos. Canada MRLs are based on the analysis of

chlorpyrifos for some commodities and on both parent chlorpyrifos and its metabolite TCP

(3,5,6

- trichloro

- 2

- pyridinol) for other commodities.

With the exce ption of apple commodities, harmonization with the Canada MRLs is not possible

as the residue definition is for the combined residues of chlorpyrifos and TCP. Harmonization

between the USA tolerances and Codex MRLs is only possible for corn, field, grain; cranberry;

egg; sorghum, grain, grain; sorghum, grain, stover ; and wheat

, grain. In addition, two

commodities of the Leafy Vegetable (CG 5) can be harmonized with the Codex , head cabbage

, and C hinese cabbage (type petsai). A summary of the US and interna tional tolerances and MRLs

is included in Table 11

.

Table 11 . Summary of US and International Tolerances and Maximum Residue Limits

Residue Definition :

US Canada Mexico 2 Codex 3

40CFR180.342

chlorpyrifos per se ( O,O

- diethyl O

- (3,5,6

- trichloro

- 2

- pyri dyl) phosphorothioate O

, O

- diethyl

- O

- (3,5,6

- trichloro

- 2

- pyridyl) phosphorothioate

(apples, grapes, tomatoes)

O

, O

- diethyl

- O

- (3,5,6

- trichloro

2

- pyridyl) phosphorothioate,

including the metabolite 3,5,6

-

trichloro

- 2

- pyridinol

(citrus fruits; fat, kidney, and

liver of cattle; kiwifruit; peppers;

rutabagas; m eat and meat

byproducts of cattle (calculated

on the fat content) Chlorpyrifos. The

residue is fat

soluble.

Commodity 1, 4 Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico 2 Codex 3

Alfalf a, forage 3.0

Alfalfa, hay 13 5 alfalfa fodder

Almond 0.2 0.05

Almond, hulls 12

Apple 0.01 0.01 1 pome fruits

Apple, wet pomace 0.02

Aspirated grain fractions 2 2

Banana 0.1 2

Beet, sugar, dried pulp 5.0

Beet, sugar, molasses 15

Beet, sugar, roots 1.0 0.05

Beet, sugar, tops 8.0

Cattle, fat 0.3 1.0

Cattle, meat 0.05 1.0 1 (fat)Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 28 of 37 Table 11 . Summary of US and International Tolerances and Maximum Residue Limits

Cattle, meat byproducts 0.05 1.0 0.01 cattle,

kidney and liver

Cherry, sweet 1.0

Cherry, tart 1 .0

Citrus, dried pulp 5.0

Citrus, oil 20

Corn, field, forage 8.0

Corn, field, grain 0.05 0.05 0.05 maize

Corn, field, refined oil 0.25 0.2 maize oil,

edible

Corn, field, stover 8.0 10 maize fodder

(dry)

Corn, sweet, forage 8.0

Corn, sweet, kernel plus cob

with husk removed 0.05 0.05 0.01 sweet corn

(corn

- on

- the

- cob)

Corn, sweet, stover 8.0

Cotton, undelinted seed 0.2 0.3 cotton seed

Cotton, gin by

- products 15

Cranberry 1.0 1

Cucumber 0.05 0.05

Egg 0.01 0.01 (*)

Fig 0.01

Fruit, citrus, g roup 10 1.0 1.0 1

Goat, fat 0.2

Goat, meat 0.05

Goat, meat byproducts 0.05

Hazelnut 0.2

Hog, fat 0.2

Hog, meat 0.05 0.02 (fat)

Hog, meat byproducts 0.05 0.01 (*) pig,

edible offal

Horse, fat 0.25

Horse, meat 0.25

Horse, meat byproducts 0.25

Kiwifruit 2.0 2.0

Lettuce 1.0

Milk, fat (Reflecting 0.01

ppm in whole milk) 0.25 0.02 milk

Nectarine 0.05 0.05

Onion, bulb 0.5 0.2

Peach 0.05 0.05 0.5

Peanut 0.2

Peanut, refined oil 0.2

Pear 0.05 1 pome fruits

Pecan 0.2 0.05 (*)Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 29 of 37 Table 11 . Summary of US and International Tolerances and Maximum Residue Limits

Pepper 1.0 1.0 2 peppers sweet

including pimento

or pimiento); 20

peppers chili,

dried

Peppermint, tops 0.8

Peppermint, oil 8.0

Plum, prune, fresh 0.05 0.5 plums

(including prunes)

Poultry, fat 0.1

Poultry, m eat 0.1 0.01 (fat)

Poultry, meat byproducts 0.1 0.01 (*) poultry,

edible offal

Pumpkin 0.05

Radish 2.0

Rutabaga 0.5 0.5

Sheep, fat 0.2

Sheep, meat 0.05 1 (fat)

Sheep, meat byproducts 0.05 0.01 sheep, edible

offal

Spearmint, tops 0.8

Spearmint, oil 8.0

Sorghum, grain, forage 0.5

Sorghum, grain, grain 0.5 0.5

Sorghum, grain, stover 2.0 2 sorghum straw

and fodder, dry

Soybean, seed 0.3 0.1 soya bean

(dry)

Strawberry 0.2 0.3

Sunflower, seed 0.1 0.1

Sweet p otato, roots 0.05

Turnip, roots 1.0

Turnip, tops 0.3

Vegetable, brassica, leafy,

group 5 1.0 2 Broccoli

1 Cabbages, head

0.05 Cauliflower

1 Chinese

cabbage (type pe

tsai)

Vegetable, legume, group 6

except soybean 0.05 0.05 lentils 0.01 c ommon

bean (pods and/or

immature seeds);

peas (pods and

succulent=immat

ure seeds)

Walnut 0.2 0.05 (*)

Wheat, forage 3.0Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 30 of 37 Table 11 . Summary of US and International Tolerances and Maximum Residue Limits

Wheat, grain 0.5 0.5

Wheat, straw 6.0 5 wheat straw and

fodder, dry

MRLs with No US Equivalents

Grapes 0.01 0.5

Tomato es 0.01

Carrot 0.1

Coffee beans 0.05

Cotton seed oil, crude 0.05 (*)

Cotton seed oil, edible 0.05 (*)

Dried grapes (=currants,

raisins and sultanas) 0.1

Potato 2

Rice 0.5

Soya bean oil, refined 0.03

Tea, green, black (bl ack,

fermented and dried) 2

Wheat flour 0.1

Completed: M. Negussie; 04/12/2011

1 Includes commodities listed in the CFR as of today.

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

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

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

fat portion of the sample. MRLs indicated as propose d have not been finalized by the CCPR and the CAC.

4 Commodities with new or reassessed tolerances being proposed are in bold.

(c) Tolerances with regional registrations. Tolerances with regional registration, as defined in 180.1(m), are

established for residues of the pesticide chlorpyrifos per se ( O,O

- diethyl

- O

- (3,5,6

- trichloro

- 2

- pyridyl)

phosphorothioate) in or on the following food commodities:

A list of the gu ideline requi rements is included in Table 12

. S tudies sub mitted after the RED and Commodity Parts per million Canada Codex

Asparagus 5.0

Grape 0.01 0.01 0.5Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 31 of 37 those corresponding to dietary burden calculations were assessed against the current guidelines

for this registration review action

. The remaining data was reassessed in th e RED according to

the corresponding OPPTS guideline. Therefore, a reassessment is not needed at this time since

the OPPTS guidelines are applicable.

Table 12 . Residue Chemistry Science Assessment for the Re gistration Review of C hlorpyrifos

.

GLN D ata Requirements Current

Tolerances

(ppm)

[40 CFR] Additional

Data

Needed? References (list all MRIDs

associated with each GLN)

860.1200: Directions for use NA Yes 1

860.1300: Plant Metabolism NA No 2

860.1300: Animal Metabolism N A No 3

860.1340: Residue Analytical Methods NA No 3

860.1380: Storage Stability NA No 3

860.1500: Magni tude of the Residue in

Plants

Almond 0.2 No 3

Apple 0.01 No 3

Banana 0.1 No 3

Beet, sugar, roots 1.0 No 3

Beet, sugar, tops 8.0 No 3

Cherry, sweet 1.0 No 3

Cherry, tart 1.0 No 3

Citrus, oil 20 No 3

Cotton, refined oil TBD Yes 7

Corn, field, grain 0.05 No 3

Corn, field, refined oil 0.25 No 3

Corn, sweet, kernel plus cob with husk

removed 0.05

No 3

Cranberry 1.0 No 3

Cucumber 0.05 No 3

Fig 0.01 No 3

Fruit, citrus, group 10 1.0 Yes 4

Hazelnut 0.2 No 3

Kiwifruit 2.0 No 3

Lettuce 1.0 No 8

Nectarine 0.05 No 3

Onion, bulb 0.5 No 3Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 32 of 37 Table 12 . Residue Chemistry Science Assessment for the Re gistration Review of C hlorpyrifos

.

GLN D ata Requirements Current

Tolerances

(ppm)

[40 CFR] Additional

Data

Needed? References (list all MRIDs

associated with each GLN)

Peach 0.05 No 3

Peanut 0.2 No 3

Peanut, refined oil 0.2 No 3

Pear 0.05 No 3

Peca n 0.2 No 3

Pepper 1.0 No 3

Peppermint, tops 0.8 No 3

Peppermint, oil 8.0 No 3

Plum, prune, fresh 0.05 No 3

Pumpkin 0.05 No 3

Radish 2.0 No 3

Rutabaga 0.5 No 3

Spearmint, tops 0.8 No 3

Spearmint, oil 8.0 No 3

Sorghum, grain, grain 0.5 No 3

Soybea n, refined oil TBD Yes 7

Soybean, seed 0.3 No 3

Strawberry 0.2 No 3

Sunflower, seed 0.1 No 3

Sweet potato, roots 0.05 No 3

Turnip, roots 1.0 No 3

Turnip, tops 0.3 No 3

Vegetable, brassica, leafy, group 5 1.0 No 3

Vegetable, legume, group 6 except

s oybean 0.05

No 3

Walnut 0.2 No 3

Wheat, grain 0.5 No 3

860.1520: Magnitude of the Residues in

Processed Food/Feed

Alfalfa, forage 3.0 No 3

Alfalfa, hay 13 No 3

Almond, hulls 12 No 3

Apple, wet pomace 0.02 No 3

Aspirated grain fractions NA No 5 46640901

Beet, sugar, dried pulp 5.0 No 3

Beet, sugar, molasses 15 No 3

Citrus, dried pulp 5.0 No 3

Corn, field, forage 8.0 No 3

Corn, field, stover 8.0 No 3

Corn, milled byproducts NA No 6

Corn, sweet, forage 8.0 No 3

Corn, sweet, stover 8.0 N o 3

Cotton, undelinted seed 0.2 No 3

Cotton, gin by

- products NA No 5 46651202Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 33 of 37 Table 12 . Residue Chemistry Science Assessment for the Re gistration Review of C hlorpyrifos

.

GLN D ata Requirements Current

Tolerances

(ppm)

[40 CFR] Additional

Data

Needed? References (list all MRIDs

associated with each GLN)

Cotton, meal TBD Yes 7

Cotton, hulls TBD Yes 7

Sorghum, grain, stover 2.0 No 3

Sorghum, grain, forage 0.5 No 3

Soybean, meal TBD Yes 7

Soybean, hulls TBD Yes 7

Wheat, hay TBD Yes 7

Wheat, forage 3.0 No 3

Wheat, milled byproducts NA No 6

Wheat, straw 6.0 No 3

860.1480: Magnitude of the Residue in

Meat, Milk, Poultry, and Eggs (Revised

version of Table 1approved in 2008)

Cattle, fat 0.3 No 3

Cattle, meat 0.0 5 No 3

Cattle, meat byproducts 0.05 No 3

Egg 0.01 No 3

Goat, fat 0.2 No 3

Goat, meat 0.05 No 3

Goat, meat byproducts 0.05 No 3

Hog, fat 0.2 No 3

Hog, meat 0.05 No 3

Hog, meat byproducts 0.05 No 3

Horse, fat 0.25 No 3

Horse, meat 0.25 No 3

Horse , meat byproducts 0.25 No 3

Milk, fat (Reflecting 0.01 ppm in whole

milk) 0.25

No 3

Poultry, fat 0.1 No 3

Poultry, meat 0.1 No 3

Poultry, meat byproducts 0.1 No 3

Sheep, fat 0.2 No 3

Sheep, meat 0.05 No 3

Sheep, meat byproducts 0.05 No 3

860. 1460: Magnitude of the Residue in

Food

- Handling Establishments No 3

860.1850: Rotational Crops (Confined) No 3

860.1900: Rotational Crops (Field) No 3Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 34 of 37 1 Label revisions are required for some crops and are noted in appropriate crop sect ion.

2 NA = Not Applies , TBD = To be determined.

3 Was reassessed in the RED according to the current version of the OPPTS guideline s , refer to the RED

for more information.

4 Crop field trials are needed to reassess the tolerance for citrus fruits due to residues over tolerance

observed during the bridging study for the microencapsulated formulation.

5 New crop field trials to support this tolerance were submitted as DCIs from the RED and reviewed in

this chapter against the current OPPTS guidelines. A tolerance of 2 2 ppm is recommended for AGF and

15 ppm for cotton gin byproducts.

6 A tolerance of 0.1 ppm for corn milled byproducts and 1.5 ppm for wheat milled by products should be

reestablished based on processing studies requirements. Refer to t he RED to find a reference to the value

recommended.

7 Processing studies are required for these commodities based on OPPTS 180.1000 guideline.

8 Tolerance to be revoked based on the absence of chlorpyrifos end use products registered to uses on

lettuce.Chlorpyrifos Summary of Analytical Chemistry and Residue Data D388164

Page 35 of 37 References

S. Knizner, Chlorpyrifos. Revised Product and Residue Chemistry Chapters of the HED Chapter

of the RED. Chem ical Number 059101., D266564, 20 /June /2000.

D. Drew, W. Britton, J. Doherty, Chlorpyrifos. Revised Human Health Assessment Scoping

Document in Support of Registration Review, D361144, 09/Feb/2009.

D. Soderberg, Chlorpyrifos. Acute Dietary Ri s k Assessment for Chlorpyrifos. Revised after

Public Comments., D263890, 22/June/2000

J. Ellenberger, Chlorpyrifos in or on Wheat. Evaluation of analytical method and residue data.,

20/Jan/1984

S. Knizner, Magnitude of the Residue in Onions and Corn Processed Commodities, D188151,

18/Aug/1993.

J. Morales, Chlorpyrifos. Magnitude of the Residue of Chlorpyrifos and 3,5 ,6

- Trichloro

- 2

- pyridinol (TCP) in Tart Cherries., D322077, 23/Aug/2006.

J. Morales, Chlorpyrifos. Magnitude of the Residue of Chlorpyrifos and 3,5,6

- Trichloro

- 2

- pyridinol (TCP) in in Aspirated Grain Fractions of Soybean, Sorghum, and Wheat., D322077,

23/A ug/2006.

J. Morales, Chlorpyrifos. Magnitude of the Residue of Chlorpyrifos and 3,5,6

- Trichloro

- 2

- pyridinol (TCP) in Cotton Gin By

- Products., D322077, 23/Aug/2006.

J.L. Martínez Vidal, F.J. Egea Gonzalez, M. Martínez Galera, M. L. Castro Cano, Diminution of

Chlorpyrifos and Chlorpyrifos Oxon in tomatoes and Green Beans Grown in Greenhouses, J.

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-

Trichloro

- 2

- pyridinol in Plant Tissues and in Tissues of Animals and Poultry Fed Chlorpyrifos in

Their Diet, 28/May/1982

.

MRID 00095270, Res idues of C hlorpyrifos and 3,5,6

- Trichloro

- 2

- pyridinol in or on S oybean

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.

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Page 37 of 37 Appendix 1 : MRL Estimate by the OECD Calculator: Chlorpyrifos in/on Cotton Gin

ByProducts

Chemical: Ch lorpyrifos

Crop: Cotton , Gin ByProducts

Region/Country: TX and CA / USA

GAP: 7.6 lb ai/A

Total number of data (n) 6

Percentage of censored data 0%

Number of non

- censored data 6

Lowest residue 0.945

Highest residue 5.850

Median residue 2.250

Mean 2.908

Standard deviation (SD) 2.053

Correction factor for censoring (CF) 1.000

Proposed MRL estimate

- Highest residue 5.850

- Mean + 4 SD 11.119

- CF x 3 Mean 8.723

Unrounded MRL 11.119

Rounded MRL 15

High uncertainty of MRL estimate.

[Small dataset]

Template Version November 2003