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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

CHEMICAL SAFETY AND

POLLUTION PREVENTION

MEMORANDUM

Date: 4 June 2015

SUBJECT: Fluensulfone – Revised Tolerance Recommendation for Tomato Paste.

PC Code: 050410 DP Barcode: D427654

Decision No.: 505068 Registration No.: 66222-243

Petition No.: 5F8365 Regulatory Action: Section 3

Risk Assessment Type: Single Chemical Aggregate Case No.: None

TXR No.: NA CAS No.: 318290-98-1

MRID No.: 49556801 40 CFR: 180.680

FROM: Michael A. Doherty, Ph.D., Senior Chemist

Risk Assessment Branch II (RAB II)

Health Effects Division (HED; 7509P)

THROUGH: Christina Swartz, Chief

RAB II 

HED (7509P)

TO: Rita Kumar/Mark Suarez/Meredith Laws

Invertebrate and Vertebrate Branch 3

Registration Division (7505P)

The new nematicide fluensulfone was recently evaluated under a global joint review project,

with Canada and Australia, for use on cucurbit and fruiting vegetables (crop groups 9 and 8-10, 

respectively). In the human health risk assessment (D403767, 18 June 2014; D422674, 4 

September 2014), HED concluded that a tolerance for residues of fluensulfone in/on both crop 

groups was supported at 0.5 ppm, and tolerances were established in September 2014 (40 CFR 

180.680). 

The tolerance expression specifies that for compliance, the analyte of interest is 3,4,4-trifluorobut-3-ene-1-sulfonic acid (a.k.a. BSA, a metabolite and degradate found in crops treated with 

fluensulfone). Based on the information available to the Agency at that time, which showed no 

concentration of fluensulfone or the BSA metabolite, separate tolerances for residues in 

processed tomato products were not established. 

Recently, the Agency received a new tomato processing study which demonstrates concentration 

of BSA to a degree that warrants a separate tolerance for residues in tomato paste. The study, 
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Magnitude of the Residue of Fluensulfone in Tomato Processed Commodities (Study No. 

AA120702; MRID 49556801), was reviewed by Health Canada’s Pest Management Regulatory

Agency (PMRA) and was found to be acceptable. EPA has not conducted additional review of 

the study. The PMRA evaluation is included as Attachment 1.

HED Conclusions

The processing study indicates that residues of BSA may concentrate in tomato puree (1.4X), 

tomato paste (3.5X), and dried tomato (6.6X). Based on these concentration factors and the 

highest average field trial (HAFT) residue (0.29 ppm)

1

in tomato fruits, the tolerance for residues 

in tomato is sufficient to cover residues in puree. The registrant has not requested a tolerance for 

residues in dried tomato, dried tomato is not a significantly traded food commodity, and a 

tolerance is not necessary for harmonization purposes; therefore, a tolerance for residues in dried 

tomato is not necessary, per HED policy. For tomato paste, the product of the concentration 

factor and the HAFT residue supports a tolerance of 1.0 ppm.

 

1 Expressed as parent compound and adjusted to reflect a mitigated application rate; see D422659, 4 September 

2014
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Attachment 1 – PMRA Evaluation of MRID 49556801 (Magnitude of the Residue of 

Fluensulfone in Tomato Processed Commodities, Study No. AA120702)

B.7.7 Effects of Industrial Processing and/or Household Preparation

(Annex IIA 6.5; Annex IIIA 8.5)

B.7.7.3 Magnitude of Residues on Set of Representative Processes

(Annex IIA 6.5.3; Annex IIIA 8.5.3)

B.7.7.3.1 TOMATO

Document ID: MRID No. 49556801

PMRA No. 2402078

Report: Magnitude of the Residue of Fluensulfone in Tomato Processed 

Commodities, Study No. AA120702

Guidelines: EPA OCSPP Harmonized Test Guideline 860.1520 Processed Food/Feed 

(August 1996)

PMRA Regulatory Directive DIR98-02 – Residue Chemistry Guidelines, 

Section 10 – Processed Food/Feed 

OECD Guideline 508 Magnitude of the Pesticide Residues in Processed 

Commodities (October 2008)

GLP Compliance: No deviations from regulatory requirements were reported which would 

have an impact on the validity of the study.

Acceptability: The study is considered scientifically acceptable.

Evaluator: Anne-Marie Boulanger, Ph.D., Scientific Evaluator III, EXP-1, HED

EXECUTIVE SUMMARY

Tomato field trials for fluensulfone were conducted in the United States during the 2012 growing 

season. Fluensulfone, formulated as an emulsifiable concentrate (EC) of 480 g/L, was applied 7 

days before transplanting of tomatoes as one pre-plant incorporated (PPI) application at rates of 

ca. 12 kg ai/ha (TRT #1) and ca. 20 kg ai/ha (TRT #2). Tomatoes were harvested only from one 

test plot of one trial (TRT #2 of T-CA) at commercial maturity (PHIs of 118-133 days). The 

tomato fruits were processed into juice, purée, paste, wet pomace and dry pomace using 

simulated commercial practices.

All RAC samples were frozen at the testing facility and remained frozen during shipping and 

storage prior to analysis. All RAC samples harvested for processing were kept cool at the testing 

facility until shipping to the processing facility and remained frozen during storage after to 

processing and prior to analysis. The maximum storage interval for samples was 83 days (i.e. 

from harvest to processing to analysis). Storage conditions and durations are supported by

studies showing that residues of fluensulfone are stable for up to 469 days in tomato RAC, and 

181 days for tomato paste and purée under frozen conditions.
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Samples were analyzed using Method 1977W, a HPLC-MS/MS method to determine residues of 

fluensulfone and M-3627 in tomato matrices. Acceptable concurrent recoveries were reported for 

tomato samples at various fortification levels, thus validating the method. The limit of 

quantitation (LOQ) was 0.01 ppm per analyte for tomato RAC, juice and purée, and 0.10 ppm 

per analyte for tomato paste, wet pomace and dry pomace.

A comparison of the residues in the raw agricultural commodity tomato fruit with those in each 

processed fraction resulted in processing factors of 1-fold for residues of fluensulfone in all 

tomato processed fractions, and processing factors of 0.66- to 6.57-fold for residues of M-3627 

in tomato processed fractions. These processing factors were less than the theoretical 

concentration factors for tomato juice, purée, paste and dry pomace.

I. MATERIALS AND METHODS

A. MATERIALS

Table 7.7.3.1-1. Nomenclature for Fluensulfone.

Common name Fluensulfone

Identity 5-chloro-2-[(3,4,4-trifluoro-3-buten-1-yl)sulfonyl]thiazole

CAS no. 318290-98-1

Company experimental name MCW-2

B. Study Design

1. Test Procedure

Location and detailed use pattern for the trial are provided in Table B.7.7.3.1-2. At each trial 

location, two treated plots were established at ca. 12 kg ai/ha (TRT #1; 4.2-fold maximum US 

registered GAP) and ca. 20 kg ai/ha (TRT #2; 7.1-fold maximum US registered GAP). The trials 

using the lower application rate were conducted due to concerns with phytotoxicity at 7.1-fold 

max GAP. However, tomato fruit samples were only collected from the 7.1-fold Californian trial 

(TRT#2) as the tomatoes matured first in California and no phytotoxicity was observed.

Table B.7.7.3.1-2. Study Use Pattern.

Location: 

City, 

State/Province; 

Year (Trial ID)

End-use 

Product/ 

Formulation

Method and 

Timing of 

Application

Volume

[L/ha]

Rate per 

Application

[kg ai/ha]

Retreatment 

Interval 

(days)

Total 

Rate

[kg 

ai/ha]

Surfactant/ 

Adjuvant

Porterville, 

CA; 2012; (TCA)

Fluensulfone 

480 g/L EC

TRT #1: one preplant incorporated 

application using 

backpack sprayer, 

7 days before 

transplanting

336.15 11.84 N/A 11.84 None
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Table B.7.7.3.1-2. Study Use Pattern.

Location: 

City, 

State/Province; 

Year (Trial ID)

End-use 

Product/ 

Formulation

Method and 

Timing of 

Application

Volume

[L/ha]

Rate per 

Application

[kg ai/ha]

Retreatment 

Interval 

(days)

Total 

Rate

[kg 

ai/ha]

Surfactant/ 

Adjuvant

TRT #2: one preplant incorporated 

application using 

backpack sprayer, 

7 days before 

transplanting

339.04 19.92 N/A 19.92 None

Dover, FL; 

2012; (T-FL)

Fluensulfone 

480 g/L EC

TRT #1: one preplant incorporated 

application using 

backpack sprayer, 

7 days before 

transplanting

276.59 11.72 N/A 11.72 None

TRT #2: one preplant incorporated 

application using 

backpack sprayer, 

7 days before 

transplanting

284.50 20.13 N/A 20.13 None

Duplicate tomato fruit samples (minimum of 12 fruits; ca. 2 kg per sample) were harvested, for 

analysis of tomato RAC, at normal commercial harvest. In addition, single bulk tomato fruit 

samples (ca. 40 kg per sample) were also harvested at normal commercial harvest and transferred 

to the processing facility for preparation of tomato juice, purée, paste and pomace (wet and dry).

Sample Handling and Preparation

Tomato RAC samples were frozen after harvest and shipped frozen to the laboratory. Tomato 

samples harvested for processing were kept cool following harvest and shipped unfrozen to the 

processing facility.

Sample Processing

Untreated tomato samples were processed before the treated tomato samples. Tomatoes were 

processed according to simulated industrial practice as closely as possible. Tomato fruits were 

first sorted for any fruits unsuitable for processing. Whole tomatoes were then placed in warm 

water at 52-57°C for 3-5 minutes to loosen extraneous material, rinsed with water, and defects or 

off-color areas were trimmed off the tomato fruits prior to processing.

Cleaned tomatoes were chopped to a fine consistency and fed into a pulper/finisher with a 6/64′′ 

screen. The material that passed through the screen was collected and heated rapidly to 91-97°C 

by pumping through a heat exchanger. The pulp material that did not pass through the screen was 

set aside. The hot break material was fed through another pulper/finisher with a 0.033′′ screen; 
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the material that did not passed through the screen was pulp. The resulting juice was checked for 

acidity and percent solids. If necessary, the acidity was adjusted to pH 4.5 or less with citric acid.

The pulp material was combined and a portion was taken for the wet pomace fraction. The 

remaining pulp was dried in an oven at 54-71°C for 20-24 hours. The resulting dry pomace was 

collected. Fractions of tomato wet and dry pomace were then stored frozen.

A portion of tomato juice was heated to 85-91°C for ca. 3 minutes, placed in a can and sealed. 

The sealed can was pressure cooked for 40-45 seconds at 121-124°C; cooled in a water bath at 

16-27°C for 28-32 minutes. Fractions of tomato juice were then stored frozen.

The remaining tomato juice was used to produce tomato paste and purée. Both paste and purée 

were produced by vacuum evaporation of water at the lowest possible temperature and highest 

possible vacuum. The juice was concentrated to percent solids of 8-24% for purée and 24-30% 

for paste. Purée and paste were then heated to 85-91°C, placed in metal cans, sealed and cooled 

in water bath at 16-27°C for 28-32 minutes. Fractions of tomato purée and paste were then stored 

frozen.

2. Description of Analytical Procedures

Samples of tomato were analyzed for residues of fluensulfone and metabolites M-3625, M-3626 

and M-3627 using the Analytical Method 1977W (PMRA # 2181331; 2181930 (ILV)). The 

method was fully validated in the Annex B.5.2 (OECD). Note: Metabolite M-3626 (i.e. methyl

sulfone) is a soil metabolite and not a plant metabolite. Metabolite M-3625 (i.e. thiazole sulfonic 

acid) is a plant metabolite. However, these two metabolites are not included in the residue 

definitions in plant commodities for enforcement and risk assessment purposes. As such, they

will not be discussed in this document.

Briefly, samples were extracted once with acetonitrile:water (ACN:H2O). For determination of 

fluensulfone (i.e. MCW-2), an aliquot of the extract was subjected to HPLC-MS/MS using 

atmospheric pressure chemical ionization in positive polarity mode (APCI(+)) with multiple 

reaction monitoring (MRM). For determination of metabolite M-3627, an aliquot of the extract 

was cleaned up by SPE (i.e. Bond Elut) and the resulting extract was analyzed HPLC-MS/MS 

using electrospray ionization in negative polarity mode (ESI(-)) with MRM. The LOQ for each 

analyte in tomato RAC, juice and purée was 0.01 ppm. The LOQ for all analytes in tomato paste, 

wet pomace and dry pomace was 0.10 ppm. The LODs were determined to be the lowest 

calibrant for each analyte resulting in values of 0.003 ppm (MCW-2) and 0.004 ppm (M3627).

II. RESULTS AND DISCUSSION

Method performance was evaluated by use of concurrent recovery samples by fortifying tomato 

RAC and processed commodities (i.e. juice, purée, paste, pomace (wet and dry)) with 

fluensulfone at 0.01 ppm and 0.10 ppm (n = 1-4 per fortification level); M-3627 at 0.01 ppm, 

0.10 ppm, 2.5 ppm, 5.0 ppm, 10 ppm and/or 20 ppm (n = 1-6 per fortification level) (Table 

B.7.7.3.1-3). The fortification levels bracketed the measured residues.
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In tomato RAC and processed commodities, the majority of individual recoveries for residues of 

fluensulfone were within the acceptable range of recoveries with a few exceptions in tomato 

paste and dry pomace at 0.01 ppm. For metabolite M-3627, very few individual recoveries were 

outside the acceptable range of recoveries. The standard deviations were also less than ± 20%.

Concurrent recoveries for each analyte were measured using both the quantitation and 

confirmation ion transitions. The data are reported in Table B.7.7.3.1-3. The confirmatory data 

are in agreement with the quantitation data but are not reported herein.

The detector response was linear (coefficient of determination, r2> 0.99) for each analyte within 

the range of 0.0005-0.100 μg/mL. Representative chromatograms of control samples, fortified 

samples and treated samples were provided. The control chromatograms generally had no peaks 

of interest above the chromatographic background at the retention time of the analytes of 

interest. Peaks were usually symmetrical and well defined.

Table B.7.7.3.1-3. Summary of Procedural/Concurrent Recoveries* of Fluensulfone and 

Metabolite M-3627 from Tomato RAC and Processed Commodities.

Matrix Fortification 

Level (ppm)

Quantitation Ion Transition

Recoveries (%) Mean ± SD (RSD) (%)

Fluensulfone (MCW-2)

Tomato RAC 0.01 80

0.10 87

Tomato juice 0.01 90, 120 105

0.10 99, 93 96

Tomato purée 0.01 100, 100 100

0.10 100, 100 100

Tomato paste 0.01 130, 100 115

0.10 97, 89 93

Tomato wet 

pomace

0.01 90, 80 85

0.10 90, 92 91

Tomato dry

pomace

0.01 150, 170, 140, 98 140 ± 30 (22)

0.10 111, 115 113

M-3627

Tomato RAC

0.01 130

0.10 100

2.5 80, 83 82

Tomato juice

0.01 110, 80 95

0.10 98, 97, 70, 83 87 ± 13 (15)

5.0 90, 73 82

Tomato purée

0.01 100, 100 100

0.10 105, 104, 91, 102 101 ± 6.5 (6.4)

5.0 100, 92 96

Tomato paste

0.01 100, 100 100

0.10 92, 118, 92, 86, 98, 91 96 ± 14 (15)

10 98, 84, 111, 87 95 ± 12 (13)
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Table B.7.7.3.1-3. Summary of Procedural/Concurrent Recoveries* of Fluensulfone and 

Metabolite M-3627 from Tomato RAC and Processed Commodities.

Matrix Fortification 

Level (ppm)

Quantitation Ion Transition

Recoveries (%) Mean ± SD (RSD) (%)

Tomato wet 

pomace

0.01 120, 90 105

0.10 100, 77, 79, 93 87 ± 11 (13)

5.0 85, 87 86

Tomato dry

pomace

0.01 80, 100 90

0.10 76, 85, 79, 75 79 ± 4.5 (5.7)

20 99, 100 100

* Recoveries in bold and red are outside the acceptable ranges of (1) 60-120% for fortification 

levels of ≤ 0.01 ppm; (2) 70-120% for > 0.01 ppm to ≤ 0.10 ppm; (3) 70-110% for > 0.1 ppm. 

Relative standard deviations in bold and red are greater than the acceptable value of (1) 30% for 

fortification levels of ≤ 0.01 ppm; (2) 20% for > 0.01 ppm to ≤ 0.10 ppm; (3) 15% for > 0.1 ppm 

≤ 1.0 ppm; (4) 10% > 1 ppm, as per OECD Guidance Document on Pesticide Residue Analytical 

Methods [ENV/JM/MONO(2007)17].

All the processed samples except tomato dry pomace were stored frozen 30 days or less from 

harvest to processing to analysis while tomato dry pomace was stored for a maximum of 83 days 

from harvest to processing to analysis (Table B.7.7.3.1-4). The available freezer storage stability

data indicate that residues of fluensulfone (MCW-2) and metabolite M-3627 were stable when 

stored frozen between -12°C and -20°C in tomato RAC for up to 469 days, and in tomato paste 

and purée for up to 181 days. Thus, the storage intervals of the tomato RAC and processed 

commodities are covered by the demonstrated storage intervals.

Table B.7.7.3.1-4. Summary of Storage Conditions.

Matrix

(RAC or Extract)

Storage 

Temperature 

(°C)

Actual Storage 

Duration

(days)

Interval of Demonstrated 

Storage Stability (days)

Tomato RAC

-20

2 469

Tomato juice 27-28

181 (paste, purée)

Tomato purée 22-26

Tomato paste 25-30

Tomato wet 

pomace

25-26

Tomato dry

pomace

82-83

Residues of fluensulfone (MCW-2) and metabolite M-3627, found in the various tomato 

samples, and their respective processing factors are given in Tables B.7.7.3.1-5.1 and B.7.7.3.1-

5.2.

The residue levels were reported using both the quantitation and confirmation ion transitions. 

The data are in agreement. However, only the data obtained using the quantitation ion transitions 

for fluensulfone and M-3627 are reported herein.
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The experimental processing factors of fluensulfone and M-3627 are less than the theoretical 

concentration factors (based on water loss or separation into components) for tomato juice and 

purée (1.4-fold) and tomato paste (5.5-fold), and the maximum observed (experimental) 

concentration factor for tomato dry pomace (80-fold) (DIR98-02; Section 10 – Processed 

Food/Feed; Appendix A; Tables 2-4).

Table B.7.7.3.1-5. Residue Data from Tomato Processing Study with Fluensulfone.

Commod

ity

Residues1(ppm) Processing Factors

MCW-2 M-3627 MCW-2 M-3627

Tomato 

(RAC)

<0.01; <0.01 2.196; 2.145

--- --- Mean <0.01 2.17

Tomato 

Juice

<0.01 1.56; 2.06 1 0.83 Mean --- 1.81

Tomato 

Purée

<0.01 3.296; 2.71 1 1.38 Mean --- 3.00

Tomato 

Paste

<0.10 8.765; 7.374; 

6.917 1

2

3.54 Media

n

--- 7.69

Tomato 

Wet 

Pomace

<0.10 1.54; 1.309

1

2 Mean 0.66

--- 1.42

Tomato 

Dry

Pomace

<0.10 15.51; 13.013

1

2 Mean 6.57

--- 14.3

1

If residues were < LOQ, they were accounted as 0.01 ppm (tomato RAC, juice, purée) or 0.10 ppm (tomato paste, wet and dry 

pomace) in the calculations. 2 The LOQs for fluensulfone in tomato RAC, and tomato paste, dry and wet pomace differ due to the 

nature of the matrix (0.01 ppm vs 0.10 ppm). However, as residues of fluensulfone were not quantifiable in any tomato matrix, a 

processing factor of 1 was assigned to tomato paste, wet and dry pomace.
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III. CONCLUSIONS

The tomato processing study is considered scientifically acceptable. A comparison of the 

residues in tomato fruit with those in each processed tomato fraction indicated that residues of 

fluensulfone do not concentrate in any of the other processed commodities of tomato. Residues 

of M-3627 concentrate in tomato purée, tomato paste and tomato dry pomace but do not 

concentrate in any other tomato processed commodities. Adequate storage stability data are 

available to support sample storage durations and conditions.

REFERENCES

PMRA # 2448366, Annex B.5.2 (OECD), Analytical methods (residue) for plants, plant 

products, foodstuffs of plant and animal origin, feedingstuffs, 26 pages.

PMRA # 2448367, Annex B.7 (OECD), Residue Data, 115 pages.