2 

Guideline MRID Study Type Study 

Classification1 Remarks

835.1230 48612101 

Adsorption/ 

Desorption (Batch 

Equilibrium) 

Supplemental 

OECD Guidelines for Testing of Chemicals, 

Guideline 121: Estimation of the Adsorption 

Coefficient (Koc) on Soil and on Sewage Sludge 

using High Performance Liquid Chromatography 

(HPLC) (adopted 22nd January 2001) was used to 

estimate Koc values for profenofos. The maximum 

single label application rate for profenofos is 1 lb 

ai/acre. It is unclear why rapid degradation of 

profenofos occurs in this study and not in similar 

studies (MRID 41627311). 

835.4300 48934901 Aerobic aquatic 

metabolism Unacceptable 

Material balances were incomplete with up to 

26.5% and 41.8% of the applied unaccounted for 

in the loamy sand (GA) and sand (NC) sediment 

systems, respectively. The limit of detection for 

the HPLC analyses was not reported. The pesticide 

use histories for the source sites for the sediments 

and waters were not reported, and the sediments 

and waters were not analyzed for pesticides to 

establish that they were not contaminated prior to 

treatment. Redox potential, dissolved oxygen and 

pH were monitored in two designated untreated 

("control") systems, per system type, at each 

sampling interval, rather than in the treated 

systems taken for analysis. All samples from a 

given treatment were connected to the same set of 

volatiles traps.

The study is classified as unacceptable due to 

serious guideline deviations and cannot be 

upgraded. EFED recommends the study be 

repeated in order to obtain valid data for use in risk 

assessment.
3 

Guideline MRID Study Type Study 

Classification1 Remarks

1

OPPIN Classifications: 

Acceptable; Acceptable/Guideline; Acceptable/Non-Guideline; Cited; Confirmatory; Decision Deferred; Extraneous 

submission; Guideline; In Review; minimum; No Decision; Partially Acceptable; Satisfactory; Screened-acceptable for 

review; Screened-not acceptable; Supplemental; Supplemental/Non-Guideline; Unacceptable; Unacceptable/Guideline; 

Unacceptable/Non-Guideline; Upgradeable. 
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Test Material: Profenofos 

MRID: 48934901 

Title: Walsh, K.J. and K.M. Campbell. 2012. Profenofos. 14C-Profenofos - 

aerobic aquatic-sediment metabolism. Final report. 

EPA PC Code: 111401 

OCSPP Guideline: 835.4300 

For CDM Smith 

Primary Reviewer: Lynne Binari Signature: 

Date: 11/25/13 

Secondary Reviewer: Kathleen Ferguson Signature: 

Date: 11/25/13 

QC/QA Manager: Joan Gaidos Signature: 

Date: 11/25/13 

Profenofos (PC 111401) MRID 48934901 

Page 3 of 31 

Observed DT50 values, calculated half-lives, and information on transformation products are listed 

in Table 1. Dissipation of profenofos and product profiles were comparable between the two 

sediment types. Two major products were detected; minor products were not identified. Analysis of 

labware extracts detected parent profenofos and product CGA55960. 

In the loamy sand sediment, extractable radioactivity increased from 0.9-1.1% of the applied at time 

0 to a maximum 23.6% at 28 days, and was 3.0-4.0% at 100 days. Unextracted radioactivity 

increased to a maximum 16.3% of the applied at 71 days and was 13.5-14.2% at 100 days. Organic 

matter fractionation (48-100 days) found 3.00-4.91%, 2.28-9.74% and 0.76-2.15% of the applied 

associated with the fulvic acids, humic acids and humin, respectively. Total evolved 14CO2 and 

other volatile compounds amounted to 29.1% and 3.0% of the applied, respectively. Radioactivity 

adsorbed to the incubation apparatus rubber stopper/connective tubing totaled 15.5-17.7% of the 

applied at 48-100 days (only intervals analyzed). 

In the sand sediment, extractable radioactivity increased from 1.4-1.6% of the applied at time 0 to a 

maximum 32.7% at 14 days, and was 2.2-2.7% at 100 days. Unextracted radioactivity increased to a 

maximum 18.1% of the applied at 48 days and was 8.7-11.9% at 100 days. Organic matter 

fractionation (48-100 days) found 2.99-5.93%, 0.77-6.68% and 0.87-3.06% of the applied 

associated with the fulvic acids, humic acids and humin, respectively. Total evolved 14CO2 and 

other volatile compounds amounted to 36.5% and 2.7% of the applied, respectively. Radioactivity 

adsorbed to the incubation apparatus rubber stopper/connective tubing totaled 7.4-13.4% of the 

applied at 48-100 days (only intervals analyzed). 
Profenofos (PC 111401) MRID 48934901 

Page 4 of 31 

Table 1. Results Synopsis: Aerobic Aquatic Metabolism of Profenofos in the Total System

Total System

Observed 

DT50

(days) 

Calculated 

Half-life 

(days) 

Model 

Parameters and 

Statistics1

Transformation Products Common Name 

(maximum % of applied observed, associated interval)

Major Minor 

Georgia pond 

water:loamy sand 

sediment (20oC, water 

pH 6.1, sediment pH 

5.1)

Profenofos 

ca. 3.5 3.34 

C0 = 98.7 

k0 = 0.809 

k1 = 0.0335 

f = 0.477 

Slow t1/2 = 20.7 

(DFOP) 

CGA55960 (52.2%, 7 days) 

CGA19941 (19.0%, 48 days) 

CO2 (29.1%, 100 days) 

Unextracted residues (16.3%, 

71 days) 

Other volatile compounds 

(3.0%, 71 days) 

4-Bromo-2-chlorophenol (CGA55960) 

ca. 25 25

C0 = 62.3 

k = 0.134 

N = 0.585 

tR IORE = 18.5 

(IORE) 

-- 

4-Bromophenol (CGA19441) 

ca. 32 28.2 

C0 = 36 

k = 0.0246 

Sc = 138 

SSFO = 95 

(SFO) 

-- 

North Carolina pond 

water:sand sediment 

system (20oC, water 

pH 6.7, sediment pH 

5.6)

Profenofos 

ca. 4 2.78 

C0 = 105 

k0 = 2.41 

k1 = 0.104 

f = 0.332 

Slow t1/2 = 6.65 

(DFOP)

CGA55960 (61.4%, 14 days) 

CO2 (36.5%, 100 days) 

Unextracted residues (18.1%, 

48 days)

CGA19941 (7.8%, 28 days) 

Other volatile compounds 

(2.7%, 48 days) 

4-Bromo-2-chlorophenol (CGA55960) 

ca. 24 9.56 

C0 = 151 

k0 = 0.0384 

k1 = 2.03 

f = 0.722 

Slow t1/2 = 18.1 

(DFOP) 

-- 

4-Bromophenol (CGA19441) 

ca. 12 9.38 

C0 = 49.7 

k = 0.0739 

Sc = 13.9 

SSFO = 9.1 

(SFO) 

-- 

1 Calculated half-lives and model parameters in accordance with the NAFTA kinetics guidance (USEPA, 2012); 

Double First Order in Parallel (DFOP), Indeterminate Order Rate Equation (IORE), and Simple First Order (SFO). 

-- = Not applicable. 
Profenofos (PC 111401) MRID 48934901 

Page 5 of 31 

I. Materials and Methods 

A. Materials 

1. Test Material: [Phenyl-U-14C]profenofos (CGA15324, pp. 17-18). 

Specific activity: 64.0 μCi/mg. 

Radiochemical purity: ≥99.0% (p. 18; Figures 4-6, pp. 55-57). 

Chemical purity: 97.7%. 

Lot/Batch No.: RDR-X-50. 

Solubility in water: 28 mg/L at 22°C (p. 17). 

2. Reference Compounds: The following compounds were used in the analysis. 

Table 2. Reference Compounds 

Applicant’s Code 

Name (synonyms) Chemical Name Purity 

(%) Lot/Batch No. 

Profenofos

(CGA15324, 

CS_13269)

IUPAC Thiophosphoric acid O-(4-bromo-2-chloro-phenyl) ester O'-ethyl 

ester S-propyl ester 98.7 AMS 137/6 

CAS Phosphorothioic acid, O-(4-bromo-2-chlorophenyl)-, O-ethyl Spropyl ester 

CGA55960 

(CS_13266) 

IUPAC 4-Bromo-2-chlorophenol 99.2 GAN-XI-46 

CAS Phenol, 4-bromo-2-chloroCGA19941 

(CS_13259) 

IUPAC 4-Bromophenol 99.6 DAH-XXV-55 

CAS Phenol, 4-bromoData obtained from pp. 17, 30; Appendix 1, p. 94 of the study report. 

-- = Not reported. 
Profenofos (PC 111401) MRID 48934901 

Page 6 of 31 

3. Water:Sediment: Water and sediment collection and characterization are summarized in Table 

3 and Tables 4a-4b, respectively. 

Table 3. Water:Sediment Collection and Storage 

Description Georgia (GA) North Carolina (NC) 

Geographic location

Private farm pond located in Adel, 

Georgia; surrounding agricultural 

usage cotton.

Farm irrigation pond (Rose Pond) 

located in Pikeville, North 

Carolina; surrounding agricultural 

usage corn, cotton and/or soybean. 

Global coordinates (approximate) N 31.16872, W -83.334732 N 35.4825 (longitude not 

reported) 

Pesticide use history at the collection site Records not retained. Not reported. 

Collection date July 6, 2011. June 28, 2011. 

Collection 

procedures 

Water: Sampled by container; no additional details were provided. 

Sediment: Sampled by shovel; no additional details were provided. 

Storage conditions

Post-sampling, water and 

sediment kept outdoors, overnight 

at ca. 75-98°F (24-37°C) prior to 

shipment to test facility; no 

additional details were provided. 

Post-sampling, water and 

sediment held at ca. 85°F 

(29.4°C) for 1 day prior to 

shipment to test facility; no 

additional details were provided. 

At test facility, water-sediment systems were stored in an incubator (4 ± 

2°C) in darkness, in a container with free access to air. 

Storage length1 13 days. 21 days. 

Preparation 

Water: Not reported. 

Sediment: 2-mm sieved. 

Data obtained from pp. 19-20; Table 1, p. 37 of the study report. 

1 Based on collection date and initiation date (July 19, 2011) of pretreatment acclimation interval (Appendix 6, pp. 161-

162). 
Profenofos (PC 111401) MRID 48934901 

Page 7 of 31 

Table 4a. Parameters for Characterization of Water:Sediment Samples - Georgia1 

Parameter

(unit) 

Field Sampling/Post 

Handling 

Stage of Test Procedure2 

Prior to Test3 During Test End of Test 

Water 

Temperature (oC) 29.6-30.0 

pH 5.0 / 6.1 6.20 6.20-6.46 6.41 

TOC (mg/L) 26.8 -- -- 

O2 (mg/L) 2.12-2.02 / 8.64 6.10 1.83-6.95 1.96 (n = 1) 

Redox potential (mV)5 +113.3 +60.8 to 

+185.0 +229.0

Sediment 

Sampling Depth 3-4 inches 

(ca. 7.6-10.2 cm) 

pH (1:1, sediment:water) 5.1 6.10 5.90-6.21 6.17 

Soil Texture (USDA) Loamy Sand 

Particle Size Distribution

81% sand (2000-50 μm) 

10% silt (50-2 μm) 

9% clay (<2 μm) 

TOC (mg/L) -- -- -- 

Organic matter (%) 1.7 

Organic carbon (%)6 1.0 

CEC (meq/100 g) 5.8 

Field Moisture 

Capacity (%) 

At 1/10 bar (pF 2): 12.8 

At 1/3 bar (pF 2.5): 9.1 

Bulk density, disturbed (g/cm3) 1.27 

Microbial biomass (μg C/g soil dry wt.) 51.3 

-- With ACN: 

3.47

-- Without ACN: 

3 .47

Redox potential (mV)5 +90.0 +87.6 to 

+202.0 +218.4

Data obtained from Tables 1-3, pp. 37-40 of the study report. Soil texture confirmed by the reviewer using USDANRCS technical support tools. 

-- = Not reported. 

1 Water and sediment characterizations performed by Agvise Laboratories, Inc. (Table 2, p. 38). 

2 Redox potential, oxygen concentration and pH measured in designated untreated ("control") systems at each 

collection interval; "control" systems received an equivalent amount (47 μL) of the test solution vehicle (acetonitrile) 

used for the [14C]profenofos treated systems (p. 20). 

3 Day 0 posttreatment interval. 

4 Determined using YSI Model 55A DO meter; non-GLP (Table 2, p. 39). 

5 Reference electrode used was not reported. 

6 Determined by reviewer: organic carbon (%) = organic matter (%) ÷ 1.72. 

7 Initial not reported. At End of Test (100 days), determined in sediments from systems with and without test solution 

vehicle (acetonitrile). 
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Table 4b. Parameters for Characterization of Water:Sediment Samples - North Carolina1 

Parameter

(unit) 

Field Sampling/Post 

Handling 

Stage of Test Procedure2 

Prior to Test3 During Test End of Test 

Water 

Temperature (oC) 27-28 

pH 6.5 / 6.74 / 7.2 7.00 5.85-7.00 6.06 

TOC (mg/L) 9.2 -- -- 

O2 (mg/L) 6.18-6.20 / 7.3 6.40 2.51-7.15 1.58 

Redox potential (mV)5 

 +112.1 +66.3 to 

+194.0 +225.0

Sediment 

Sampling Depth 5-10 cm 

pH (1:1, sediment:water) 5.6 6.80 5.94-6.80 6.35 

Soil Texture (USDA) Sand 

Particle Size Distribution

97% sand (2000-50 μm) 

3% silt (50-2 μm) 

0% clay (<2 μm) 

TOC (mg/L) -- -- -- 

Organic matter (%) 3.5 

Organic carbon (%)6 2.0 

CEC (meq/100 g) 3.6 

Field Moisture 

Capacity (%) 

At 1/10 bar (pF 2): 8.5 

At 1/3 bar (pF 2.5): 5.5 

Bulk density, disturbed (g/cm3) 1.00 

Microbial biomass (μg C/g soil dry wt.) 72.2 

-- With ACN: 

3.47

-- Without ACN: 

24.0 

Redox potential (mV)5 

 +68.9 +68.0 to 

+204.0 +232.9

Data obtained from Tables 1-3, pp. 37-40 of the study report. Soil texture confirmed by the reviewer using USDANRCS technical support tools. 

-- = Not reported. 

1 Water and sediment characterizations performed by Agvise Laboratories, Inc. (Table 2, p. 38). 

2 Redox potential, oxygen concentration and pH measured in designated untreated ("control") systems at each 

collection interval; "control" systems received an equivalent amount (47 μL) of the test solution vehicle (acetonitrile) 

used for the [14C]profenofos treated systems (p. 20). 

3 Day 0 posttreatment interval. 

4 An "earlier" determination not conducted under GLP (Table 2, p. 39). 

5 Reference electrode used was not reported. 

6 Determined by reviewer: organic carbon (%) = organic matter (%) ÷ 1.72. 

7 Initial not reported. At End of Test (100 days), determined in sediments from systems with and without test solution 

vehicle (acetonitrile). 
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B. Study Design

Preliminary experiments were conducted to determine parameters for the definitive study, including 

0-7 day incubations and analyses of treated systems which yielded total mass balances of >90% of 

the applied radioactivity; no additional details regarding preliminary work were provided (p. 16). 

1. Experimental Conditions: Table 5 summarizes the experimental conditions. 

Table 5. Experimental Design 

Experimental Design Georgia (GA) Loamy Sand North Carolina (NC) Sand 

Duration of the test 100 days 

Water: 

Type and size of filter used None reported. 

Amount of sediment and water per treatment: 

Water ca. 180 mL 

Sediment 80 g dry wt. 50 g dry wt. 

Water/sediment ratio mL:g dry wt. ca. 2.3:1 (ca. 180 mL:80 g dry 

wt.) 

ca. 3.6:1 (ca. 180 mL:50 g dry 

wt.) 

cm:cm 3:1 (ca. 7.5 cm water layer:ca. 2.5 cm sediment layer) 

Application rates: 

Nominal 0.374 mg a.i./L 

Actual (Appendix 2, p. 221) 0.372 mg a.i./L (67 μg a.i./180 mL water). 

Number of replicates:

Control, if used Sterile controls were not used. 

Treated Sufficient water:sediment systems were treated to allow for duplicate 

systems, per system type, at each sampling interval. 

Test apparatus: 

Type/material/volume

Wide-mouth, glass bottles (8 oz., i.d. 5.5 cm), sealed with rubber 

stoppers partially wrapped with Teflon tape, connected to a continuous 

flow-through (humidified air, flow rate not reported) volatiles trapping 

system (Figure 1, p. 52). Glass and Tygon (or PVC) tubing were used 

to connect incubation flasks and volatiles traps. All incubation vessels 

per system type (loamy sand, sand) were connected to the same set of 

volatiles traps. 

Details of traps for CO2 and organic volatile, if 

any

Polyurethane foam plug and ethylene glycol (one trap) to collect 

organic volatiles and 1.0N NaOH solution (two traps) to collect CO2; 

trapping solution volumes not reported. At 22 days posttreatment, 

activated carbon traps and/or an in-line combustor (catalytic converter) 

were added (Figure 1, p. 52). 

If no traps were used, is the system closed? Volatiles traps were used. 

Identity and final concentration (based on 

water volume) of co-solvent Acetonitrile; 0.03% by volume (47 μL test solution/180 mL water 

Test material application method: 

Volume of the test solution used/treatment 47 μL 

Application method (i.e., mixed/not mixed) The test solution was applied to the water using a 50-μL Hamilton 

glass syringe 

Any indication of the test material adsorbing 

to the walls of the test apparatus?

Yes; decreasing mass balances at 14-100 days posttreatment attributed 

to adsorption of radioactivity to the rubber stoppers, used to seal the 

incubation flasks, and the Tygon (or PVC) connective tubing. 

Microbial biomass/population of control 

(units): Sterile controls were not used.

Water -- 
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Experimental Design Georgia (GA) Loamy Sand North Carolina (NC) Sand 

Sediment -- 

Microbial biomass/population of treated 

(units): Not determined in treated systems 

Water -- 

Sediment -- 

Experimental conditions: 

Temperature 20 ± 2oC 

Continuous darkness (yes/no) Yes 

Other details (if any)

The water:sediment systems were acclimated to test conditions for 14-

19 days prior to treatment. 

Water volumes of the test systems were maintained during 

pretreatment acclimation and posttreatment by gravimetric 

determination.

Untreated ("control") systems (number not specified), per system type, 

were prepared and maintained for system parameter (redox potential, 

dissolved oxygen, pH) measurements and biomass determinations.

"Control" systems received an equivalent amount (47 μL) of the test 

solution vehicle (acetonitrile) used for the [

14C]profenofos treated 

systems.

The nominal application rate of 0.374 mg a.i./L used in this study was 

reported as equivalent to a single maximum field application rate of 1 

lb a.i./A (ca. 1,121 g a.i./ha. 

Data obtained from pp. 17, 20-23, 27; Table 2, p. 38; Tables 3-5, pp. 40-42; Figure 1, p. 52; Appendix 4, p. 106 of the 

study report. 

2. Sampling during Study Period: Table 6 summarizes sampling during the study period. 

Table 6. Sampling during Study Period 

Parameter Details 

Sampling intervals (duration) 0, 0.5, 1, 3, 7, 14, 28, 48, 71 and 100 days posttreatment. 

Sampling method Per system type, duplicate samples were collected at each sampling 

interval. 

Method of collection of CO2 and organic 

volatile compounds 

Respective volatiles traps were collected at each sampling interval 

after day 0. 

Sampling Intervals/Times 

Redox potential in water layer 

Measured in designated untreated ("control") systems, per system 

type, at each collection interval, excluding day 0.5. 

Methods/equipment used to measure system parameters were not 

reported.

Dissolved oxygen in water layer 

pH in water layer 

Redox potential in sediment 

pH in sediment 

Other details, if any 

Water and sediment were separated and the sediment extracted the 

day of collection. Day 0-48 water layer and sediment extract 

samples were analyzed by HPLC within 48 hours of collection. Day 

71 and 100 samples were analyzed by HPLC 36-37 days and 7-8 

days, respectively, after collection. Samples were stored frozen until 

analysis. Reanalysis of day 0 loamy sand (GA) system water layer 

and sediment extract samples after ca. 1 year of frozen storage 

detected only parent profenofos; quantitative results were not 

provided. 
Profenofos (PC 111401) MRID 48934901 

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Data obtained from pp. 21, 23-24; Tables 3-5, pp. 40-42; Appendix 6, pp. 161-162; Appendix 8, pp. 166-168 of the 

study report. 

3. Analytical Procedures:

Separation of the Water and Sediment: The water layer was separated from the sediment by 

decanting "and/or after centrifugation"; method not further described (p. 23). 

Extraction/Clean Up/Concentration Methods: Water layer samples were analyzed directly; 

aliquots were analyzed by LSC and HPLC (p. 23). 

An aliquot (10 mL) of day 14 loamy sand (GA) system Rep 1 water layer was partitioned twice 

with methylene chloride (20 mL x 2); ca. 5.9% remained in aqueous phase (p. 24; Appendix 2, p. 

100). Organic phases were combined, concentrated (method not reported, procedural recovery ca. 

97.9%), and analyzed by TLC. 

Sediment was sequentially extracted once with acetonitrile followed by once with acetonitrile:water 

(50:50, v:v); extraction solvent volumes were 200 mL (p. 23; Figure 2, p. 53). Extraction method 

and separation of extract and sediment were not described. Extracts were combined and 

concentrated by rotary evaporation (35°C, 28 inches Hg); procedural recoveries were reported as 

90.0-105.7% (p. 29). Aliquots were analyzed by LSC and HPLC. 

An aliquot (10 mL) of day 14 loamy sand (GA) system Rep 1 pooled extract was diluted with water 

(10 mL), concentrated to ca. 9 mL (method not reported), then partitioned twice with methylene 

chloride (20 mL x 2); ca. 5.9% remained in aqueous phase (p. 24; Appendix 2, p. 100). The initial 

organic phase was concentrated (method not reported, procedural recovery ca. 99.9%) and analyzed 

by TLC. 

Determination of Unextracted Residues: Extracted sediment was analyzed for total radioactivity 

by LSC following combustion (p. 19; Appendix 2, p. 95). Oxidizer efficiency was reported as 

≥96.4% (Appendix 2, p. 95).

Organic matter fractionation. Day 48-100 extracted sediment samples were characterized using 

standard organic matter fractionation techniques (p. 24; Figure 3, p. 54). Fulvic acid and humic acid 

fractions were analyzed for total radioactivity by LSC and the humin by LSC following combustion. 

Determination of Volatile Residues: Aliquots of the ethylene glycol and NaOH trapping solutions 

were analyzed for total radioactivity using LSC (p. 24). Foam plugs were extracted (method not 

described) and the extract analyzed using LSC (Appendix 4, p. 110). Solid adsorbent (activated 

carbon) was analyzed either directly by LSC or LSC following combustion; no additional details 

were provided (p. 24). 

Day 28-71 NaOH trapping solutions were analyzed for dissolved 14CO2 using standard barium 

chloride precipitation techniques (p. 24). 

Determination of Residues Adsorbed to Incubation Apparatus: Rubber stoppers, Teflon tape 

used on the stoppers, and connective tubing from day 48-100 systems were separately extracted 

(method not reported) with acetonitrile followed by methylene chloride; extraction solvent volumes 

were 20-100 mL (Appendix 3, p. 103). Extracts were separately analyzed using LSC. Extracted 
Profenofos (PC 111401) MRID 48934901 

Page 12 of 31 

stoppers and tubing were cut into pieces and analyzed either directly by LSC or LSC following 

combustion; no additional details were provided (Appendix 3, p. 105). 

Total Radioactivity Measurement: Total [14C] residues were determined by summing the 

concentrations of residues measured in the water layer, sediment extracts, extracted sediment and 

trapping materials (Appendix 4, p. 111). Due to declining mass balances, day 48-100 total 

recoveries were recalculated to include [14C] residues recovered from the incubation apparatus 

stoppers/connective tubing (Tables 4-5, pp. 41-42). 

Derivatization Method: None reported. 

Identification and Quantification of Parent Compound: Water layer, sediment extract, and 

apparatus extract samples were analyzed by HPLC using a Synergi Hydro RP column (4.6 x 250 

mm, 4 μ, 80Å) eluted with a gradient mobile phase of (A) aqueous 0.1% acetic acid and (B) 

acetonitrile (p. 19; Appendix 2, pp. 95-98). The eluent was monitored with radioactivity and UV 

(254 nm) detectors. Column recoveries for day 0 loamy sand (GA) Rep 1 water layer and sediment 

extract samples were 92.3% and 93.5%, respectively (Appendix 2, p. 98). Parent [14C]profenofos 

was identified by co-chromatography with and comparison to the retention time of unlabeled 

profenofos (Figures 9-26, pp. 60-85). HPLC was the primary quantification method (p. 19). 

Identification of parent was confirmed in day 14 GA Rep 1 water layer and sediment extract 

samples using one-dimensional TLC developed with chloroform:petroleum ether (70:30, v:v; p. 24; 

Appendix 2, pp. 99-102). Following development, radioactive areas were detected using a Bioscan 

System AR2000 Imaging Scanner. Parent [14C]profenofos in the samples was identified by cochromatography with unlabeled reference compound which was visualized under UV light (254 

nm). 

Identification and Quantification of Transformation Products: Transformation products were 

separated and quantified using HPLC, with identifications confirmed by TLC, as described for 

parent (pp. 19, 24; Figures 10-17, pp. 62-73; Figures 19-26, pp. 76-85; Appendix 2, pp. 95-102). 

Detection Limits (LOD, LOQ) for the Parent Compound and Transformation Products: The 

limit of quantitation (LOQ) for HPLC analyses was 0.004% of the applied (ca. 0.003 μg); the limit 

of detection (LOD) was not reported (Appendix 2, p. 98). For LSC analyses, LOD was twice 

background radioactivity (ca. 32 dpm), and the LOQ was 64 dpm (ca. 0.00045 μg; Appendix 2, p. 

95). 
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II. Results and Discussion 

A. Data: 

Study results, including total mass balances and distribution of radioactivity, are presented in 

Tables 7a and 7b. The incubation temperature (20 ± 2oC) was maintained, except at 12-13 days 

posttreatment when the temperature reached 27°C (p. 21; Appendix 7, pp. 163-164). System 

parameters (redox potential, dissolved oxygen, pH) were not measured in the treated systems taken 

for analysis, but in designated untreated systems. Sediment (loamy sand, sand) microbial biomass 

decreased from 51.3-72.2 μg C/g soil dry wt. prior to start of the experiment to 3.4 μg C/g soil dry 

wt. (n = 2) after 100 days in sediments from systems treated with the test solution vehicle 

(acetonitrile; Table 2, p. 38). 

In the water column of untreated loamy sand (GA) sediment systems, redox potentials, dissolved 

oxygen and pH were +60.8 to +229.0 mV, 1.83-6.95 mg/L and 6.20-6.46, respectively, with redox 

potentials and pH in the sediment of +87.6 to +218.0 mV and 5.90-6.21, respectively (Table 3, p. 

40). In the water column of untreated sand (NC) sediment systems, redox potentials, dissolved 

oxygen and pH were +66.3 to +225.0 mV, 1.58-7.15 mg/L and 5.85-7.00, respectively, with redox 

potentials and pH in the sediment of +68.0 to +232.9 mV and 5.94-6.80, respectively. 

B. Mass Balance: 

In the loamy sand (GA) sediment system, recoveries ranged from 73.5% to 105.5% of the applied 

(Table 4, p. 41). Recoveries declined throughout the experiment and were below guideline criteria 

(>90% - <110%) at 14-100 days. In the water column profenofos decreased from 95.6-104.5% of 

the applied at time 0 to ≤1.7% at 71 days and was not detected (LOQ = 0.004% of applied) at 100 

days (Table 7, p. 44). In the sediment profenofos increased from 3.3% (n = 2) of the applied at 1 

day to a maximum 8.3% at 28 days and was not detected at 100 days (Table 8, p. 45). 

In the sand (NC) sediment system, recoveries ranged from 58.2% to 107.1% of the applied (Table 5, 

p. 42). Recoveries declined throughout the experiment and were below guideline criteria (>90% - 

<110%) at 14-100 days. In the water column profenofos decreased from 102.6-105.5% of the 

applied at time 0 to ≤2.0% at 28-71 days and was not detected at 100 days (Table 10, p. 47). In the 

sediment profenofos increased from 3.1-4.7% of the applied at 0.5 day to a maximum 17.0% at 7 

days and was ≤2.4% at 100 days (Table 11, p. 48). 

C. Bound and Extractable Residues:

In the loamy sand (GA) sediment, extractable radioactivity increased from 0.9-1.1% of the applied 

at time 0 to a maximum 23.6% at 28 days, and was 3.0-4.0% at 100 days (Table 4, p. 41). 

Unextracted radioactivity increased from 0.1% (n = 2) of the applied at 0-3 days to a maximum 

16.3% at 71 days and was 13.5-14.2% at 100 days. In day 48-100 extracted sediment, organic 

matter fractionation found 3.00-4.91%, 2.28-9.74% and 0.76-2.15% of the applied associated with 

the fulvic acids, humic acids and humin, respectively (Table 6, p. 43). 

In the sand (NC) sediment, extractable radioactivity increased from 1.4-1.6% of the applied at time 

0 to a maximum 32.7% at 14 days, and was 2.2-2.7% at 100 days (Table 5, p. 42). Unextracted 

radioactivity increased from 0.1-0.2% of the applied at day 0 to a maximum 18.1% at 48 days and 

was 8.7-11.9% at 100 days. In day 48-100 extracted sediment, organic matter fractionation found 
Profenofos (PC 111401) MRID 48934901 

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2.99-5.93%, 0.77-6.68% and 0.87-3.06% of the applied associated with the fulvic acids, humic 

acids and humin, respectively (Table 6, p. 43). 

 

D. Volatilization:

Volatile 14CO2 totaled 29.1% and 36.5% of the applied at 100 days in the loamy sand (GA) and 

sand (NC) sediment systems, respectively; identification was reportedly confirmed, but quantitative 

results were not provided (p. 28; Tables 4-5, pp. 41-42). Other volatile compounds were detected at 

maximums of 3.0% (71 days) and 2.7% (48 days) of the applied in the loamy sand (GA) and sand 

(NC) sediment systems, respectively. 

Radioactivity adsorbed to the incubation apparatus rubber stopper/connective tubing totaled 15.5-

17.7% and 7.4-13.4% of the applied at 48-100 days (only intervals analyzed) in the loamy sand and 

sand sediment systems, respectively (DER Attachment 2). Analysis of stopper/connective tubing 

extracts detected parent profenofos and product CGA55960 (Figures 25-26, pp. 83-85). 
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Table 7a. Transformation of Profenofos, Expressed as Percentage of the Applied Radioactivity, in Aerobic Pond Water:Loamy Sand Sediment System

Sampling Interval (days) 0 0.5 1 3 7 14 28 48 71 100 Replicate Number 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 Profenofos 95.6 104.5 81.2 75.9 81.2 65.6 52.2 50.1 42.2 43.9 26.7 30.0 21.1 20.0 13.5 11.8 6.5 4.2 n.d. n.d. CGA55960 n.d. n.d. 16.2 17.9 16.5 26.9 44.4 46.4 52.2 48.2 46.3 46.0 29.9 25.8 13.1 12.9 1.1 0.6 n.d. n.d. CGA19941 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 5.9 4.7 16.4 17.3 11.1 19.0 1.7 3.7 3.0 4.0 Unknowns1 1.1 0.9 1.3 1.0 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 2.5 2.5 6.4 2.9 11.6 10.6 11.4 8.6 Extracted sediment residues 1.1 0.9 1.3 1.0 3.6 3.7 1.6 1.7 3.9 2.4 10.1 10.7 19.1 23.6 16.2 20.2 9.2 6.8 3.0 4.0 Unextracted sediment residues 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.3 0.3 1.2 1.3 4.0 4.6 12.5 8.0 15.3 16.3 13.5 14.2 

Fulvic acids 3.49 3.00 3.99 4.91 4.41 4.11 Humic acids n.p. 2.28 2.95 8.29 9.74 5.66 5.65 Humin 1.15 0.76 1.50 2.15 1.82 1.47 

CO22 n.p. n.p. n.p. n.p. 0.0 0.0 0.1 0.1 0.3 0.3 0.6 0.6 2.0 2.0 7.9 7.9 20.5 20.5 29.1 29.1 Other volatile compounds2 n.p. n.p. n.p. n.p. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.8 0.8 3.0 3.0 2.4 2.4 Apparatus (stopper/tubing) 17.7 16.3 17.1 15.8 16.7 15.5 

Extracts n.p. 15.2 13.8 12.8 10.5 12.8 11.7 Unextracted on stopper 2.5 2.4 4.1 5.1 3.7 3.6 Unextracted on tubing 0.0 0.1 0.2 0.2 0.2 0.2 

Mass balance 96.8 105.5 98.8 94.9 97.9 92.6 96.7 96.7 95.1 92.7 80.9 82.6 77.2 73.5 80.8 79.7 76.8 74.6 76.2 74.0 

Data obtained from Table 4, p. 41; Table 6, p. 43; Table 9, p. 46 of the study report and DER Attachment 2 (Unknowns, Apparatus); total system summations for parent and products confirmed. n.d. = Not detected. n.p. = Not performed. 1 Day 0 and 0.5 = unanalyzed sediment extracts. At remaining intervals, up to nine components, with no individual component detected at >7.8% of applied (Table 9, p. 

46). 

2 All samples connected to same set of volatiles traps (p. 21). 14CO2 identification reportedly confirmed (p. 28). 
Profenofos (PC 111401) MRID 48934901 

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Table 7b. Transformation of Profenofos, Expressed as Percentage of the Applied Radioactivity, in Aerobic Pond Water:Sand Sediment System

Sampling Interval (days) 0 0.5 1 3 7 14 28 48 71 100 Replicate Number 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 Profenofos 105.5 102.6 82.4 81.2 62.4 53.2 55.2 58.3 30.3 36.7 14.6 15.8 n.d. 3.0 2.0 2.5 4.7 3.6 n.d. 2.4 CGA55960 n.d. n.d. 9.1 11.1 30.1 39.9 36.4 35.9 60.0 56.1 61.1 61.4 45.4 39.7 13.0 21.6 1.4 0.6 1.4 0.3 CGA19941 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 1.3 1.3 4.8 7.8 n.d. 2.7 0.8 n.d. 0.8 n.d. Unknowns1 1.4 1.6 n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 2.4 2.6 6.5 5.2 4.1 9.1 2.5 2.2 Extracted sediment residues 1.4 1.6 3.1 4.7 14.9 16.6 9.1 16.4 29.1 17.0 32.7 29.4 25.5 26.5 8.7 12.8 4.1 4.2 2.2 2.7 Unextracted sediment residues 0.2 0.2 0.1 0.1 0.5 0.3 0.3 0.6 1.9 1.0 3.3 3.1 9.7 8.4 18.1 10.8 11.4 11.4 11.9 8.7 

Fulvic acids 5.93 3.76 3.74 3.60 3.38 2.99 Humic acids n.p. 6.68 4.16 1.29 0.77 2.01 2.57 Humin 3.06 0.87 2.05 1.66 1.96 1.20 

CO22 n.p. n.p. n.p. n.p. 0.0 0.0 0.0 0.0 0.1 0.1 1.0 1.0 6.1 6.1 17.7 17.7 23.2 23.2 36.5 36.5 Other volatile compounds2 n.p. n.p. n.p. n.p. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.4 2.7 2.7 1.6 1.6 0.6 0.6 Apparatus (stopper/tubing) 10.4 13.4 11.9 11.6 12.4 7.4 

Extracts n.p. 9.0 11.4 8.6 7.9 9.5 7.2 Unextracted on stopper 1.4 2.0 3.2 3.6 2.8 0.1 Unextracted on tubing 0.0 n.p. 0.1 0.1 0.1 0.1 

Mass balance 107.1 104.4 91.6 92.5 93.0 93.5 91.9 94.8 92.4 93.8 81.3 82.6 68.7 68.0 70.4 76.7 59.0 61.1 66.2 58.2 

Data obtained from Tables 5-6, pp. 42-43; Table 12, p. 49 of the study report and DER Attachment 2 (Unknowns, Apparatus); total system summations for parent and products confirmed. n.d. = Not detected. n.p. = Not performed. 1 Day 0 = unanalyzed sediment extracts. At remaining intervals, up to five components, with no individual component detected at >4.4% of applied (Table 12, p. 49). 2 All samples connected to same set of volatiles traps (p. 21). 14CO2 identification reportedly confirmed (p. 28). 
Profenofos (PC 111401) MRID 48934901 

Page 17 of 31 

E. Transformation of Parent Compound: Transformation kinetics of the parent compound are 

summarized in Figures 1a and 1b (DER Attachment 2) and Table 8, with transformation product 

information summarized in Table 9. 

Transformation kinetics of profenofos in the systems were calculated by the reviewer using PestDF. 

The best fit calculated half-life values, shown in Table 8, for profenofos in the total system were 

20.7 days and 6.65 days for the loamy sand (GA) and sand (NC) sediment systems, respectively. 

Table 8. Transformation Kinetics of Profenofos in Total Aquatic Systems1, 2 

System

Observed 

DT50 

(days)3 

Observed 

DT90 

(days)3 

Calculated

Half-life

(days) 

Kinetics 

Model4 Model Parameters Model Statistics 

Georgia pond 

water:loamy sand 

sediment (20oC, 

water pH 6.1, 

sediment pH 5.1) 

ca. 3.5 ca. 56 

8.46 SFO C0 = 83.6, k = 0.082 Sc = 638, 

SSFO = 1.8e+03 

21.9 IORE C0 = 96.2, k = 0.000243, 

N = 2.57 

tR IORE = 21.9 

20.7 DFOP 

[if applicable]

C0 = 98.7, k0 = 0.809, 

k1 = 0.0335, 

f = 0.477 

Slow t1/2 = 20.7 

North Carolina pond 

water:sand sediment 

system (20oC, water 

pH 6.7, sediment pH 

5.6)

ca. 4 ca. 19 

4.51 SFO C0 = 89.2, k = 0.154 Sc = 1.08e+03, 

SSFO = 1.34e+03 

7.53 IORE C0 = 98.9, k = 0.00316, 

N = 2.05 

tR IORE = 7.53 

6.65 DFOP 

[if applicable]

C0 = 105, k0 = 2.41, 

k1 = 0.104, 

f = 0.332

Slow t1/2 = 6.65 

1 Kinetics values calculated by the reviewer using R v. xxDeg_0.8.4 and data obtained from Table 9, p. 46; Table 12, 

p. 49 of the study report (DER Attachment 2). 

2 Calculated half-lives and model parameters in accordance with the NAFTA kinetics guidance (USEPA, 2012), are in

bold. 

3 Based on mean profenofos levels at each interval.

4 Kinetics models: Simple First Order (SFO), Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE). 

Two products were identified in both systems (p. 30; Appendix 1, p. 94): 

x 4-bromo-2-chlorophenol (CGA55960) and 

x 4-bromophenol (CGA19441). 

CGA55960 was a major product in both systems, while CGA19441 was a major product in the 

loamy sand (GA) sediment system, but a minor product in the sand (NC) sediment system. 

Identifications of products were made by co-chromatography with reference standards (p. 29). 
Profenofos (PC 111401) MRID 48934901 

Page 18 of 31 

Table 9. Transformation Products of Profenofos in Total Aquatic Systems

System Transformation 

product(s) 

Maximum 

%AR 

Observed 

Associated 

Interval 

(days) 

Final %AR 

Observed1

Final Interval 

(days)

Georgia pond water:loamy 

sand sediment (20oC, 

water pH 6.1, sediment pH 

5.1) 

CGA55960 52.2 7 n.d. 100 

CGA19941 19.0 48 4.0 100 

North Carolina pond 

water:sand sediment 

system (20oC, water pH 

6.7, sediment pH 5.6) 

CGA55960 61.4 14 1.4 100 

CGA19941 7.8 28 0.8 100 

Data obtained from Table 9, p. 46; Table 12, p. 49 of the study report. 

n.d. = Not detected; LOQ = 0.004% of applied (Appendix 2, p. 98).

1 Maximum value. 

Transformation kinetics of CGA55960 are summarized in Figures 2a and 2b (DER Attachment 2)

and Table 10. Transformation kinetics of CGA19941 are summarized in Figures 3a and 3b (DER 

Attachment 2) and Table 11; although the maximum CGA19941 level detected in the sand 

sediment system was low (7.8% of applied), there was a pattern of decline and half-lives were 

calculated for comparison to the loamy sand sediment system. 

Table 10. Transformation Kinetics of Profenofos Product CGA55960 in Total Aquatic 

Systems1, 2 

System

Observed 

DT50 

(days)3 

Observed 

DT90 

(days)3 

Calculated

Half-life

(days) 

Kinetics 

Model4 Model Parameters Model Statistics 

Georgia pond 

water:loamy sand 

sediment (20oC, 

water pH 6.1, 

sediment pH 5.1) 

ca. 25 ca. 56 

20 SFO C0 = 68.5, k = 0.0347 Sc = 67.3, 

SSFO = 140 

18.5 IORE C0 = 62.3, k = 0.134, 

N = 0.585 

tR IORE = 18.5 

20 DFOP 

[if applicable]

C0 = 131, k0 = 0.0347, 

k1 = 3.73, 

f = 0.523

Slow t1/2 = 20 

North Carolina pond 

water:sand sediment 

system (20oC, water 

pH 6.7, sediment pH 

5.6)

ca. 24 ca. 50 

18.1 SFO C0 = 109, k = 0.0384 Sc = 125, 

SSFO = 203 

18.1 IORE C0 = 91.2, k = 0.152, 

N = 0.601 

tR IORE = 18.1 

18.1 DFOP 

[if applicable]

C0 = 151, k0 = 0.0384, 

k1 = 2.03, 

f = 0.722 

Slow t1/2 = 18.1 

1 Kinetics values calculated by the reviewer using R v. xxDeg_0.8.4 and data obtained from Table 9, p. 46; Table 12, 

p. 49 of the study report (DER Attachment 2). 

2 Calculated half-lives and model parameters for the best fit kinetics model, in accordance with the NAFTA kinetics 

guidance (USEPA, 2011), are in bold. 

3 Based on mean CGA55960 levels at each interval from interval of maximum mean detection.

4 Kinetics models: Simple First Order (SFO), Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE). 
Profenofos (PC 111401) MRID 48934901 

Page 19 of 31 

Table 11. Transformation Kinetics of Profenofos Product CGA19941 in Total Aquatic 

Systems1, 2 

System 

Observed 

DT50 

(days)3 

Observed 

DT90 

(days)3 

Calculated

Half-life

(days) 

Kinetics 

Model4 Model Parameters Model Statistics 

Georgia pond 

water:loamy sand 

sediment (20oC, 

water pH 6.1, 

sediment pH 5.1) 

ca. 32 >72 

28.2 SFO C0 = 36, k = 0.0246 Sc = 138, 

SSFO = 95 

38.1 IORE C0 = 29.2, k = 0.0719, 

N = 0.548 

tR IORE = 27.6 

4.91 DFOP 

[if applicable]

C0 = -894, k0 = 0.0664, 

k1 = 0.11, 

f = -0.59

Slow t1/2 = 10.4 

North Carolina pond 

water:sand sediment 

system (20oC, water 

pH 6.7, sediment pH 

5.6)

ca. 12 ca. 38 

9.38 SFO C0 = 49.7, k = 0.0739 Sc = 13.9, 

SSFO = 9.1 

5.72 IORE C0 = 107, k = 0.0612, 

N = 1.16 tR IORE = 6.52 

8.52 DFOP 

[if applicable]

C0 = 60.9, k0 = 0.0815, 

k1 = -0.0199, 

f = 0.999 

Slow t1/2 = -34.7 

1 Kinetics values calculated by the reviewer using R v. xxDeg_0.8.4 and data obtained from Table 9, p. 46; Table 12, p. 

49 of the study report (DER Attachment 2). 

2 Calculated half-lives and model parameters for the best fit kinetics model, in accordance with the NAFTA kinetics 

guidance (USEPA, 2011), are in bold. 

3 Based on mean CGA19941 levels at each interval from interval of maximum mean detection.

4 Kinetics models: Simple First Order (SFO), Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 20 of 31 

A transformation pathway was provided by the study authors and is illustrated below (p. 30; Figure 

33, p. 92). Transformation occurred through hydrolytic cleavage of the phosphorothioate moiety 

and reductive de-chlorination to yield major products 4-bromo-2-chlorophenol (CGA55960) and 4-

bromophenol (CGA19941), several minor products (unidentified), sediment bound residues, and 

mineralization to CO2. 

Figure 4. Aerobic Aquatic Degradation Pathway of Profenofos. 
Profenofos (PC 111401) MRID 48934901 

Page 21 of 31 

III. Study Deficiencies and Reviewer's Comments 

1. Material balances were incomplete with up to 26.5% and 41.8% of the applied unaccounted for 

in the loamy sand (GA) and sand (NC) sediment systems, respectively (Tables 4-5, pp. 41-42). 

Analysis of extracts from incubation apparatus rubber stoppers, Teflon tape and connective 

tubing indicated some volatilization and adsorption of parent profenofos and product 

CGA55960 (Figures 25-26, pp. 83-85). Possible adsorption to the glass incubation vessels, 

however, was not investigated (p. 34). Addition of activated carbon and/or in-line catalytic 

converter traps recovered only ≤3.0% of the applied at 28-100 days, indicating other volatile 

compounds were not "readily escaping" the trapping system (p. 31; Tables 4-5, pp. 41-42). 

However, even with extraction of the labware and addition of activated carbon/catalytic 

converter traps, material balances continued to decline at 48-100 days. The study authors 

contend that declining material balances at the later sampling intervals did not "adversely 

impact" profenofos kinetics calculations or determination of the profenofos transformation 

pathway (p. 32). However, declining material balances impacts the patterns of formation and 

decline of profenofos transformation products, including maximum levels of the products 

(identified and unidentified) detected. 

2. The limit of detection for the HPLC analyses was not reported. 

3. The pesticide use histories for the source sites for the sediments and waters were not reported. 

Both source sites were farm ponds with surrounding agricultural usage of either cotton 

(Georgia) or corn, cotton and/or soybean (North Carolina; Table 1, p. 37). The sediments and 

waters were not analyzed for pesticides to establish that they were not contaminated prior to 

treatment. 

4. Redox potential, dissolved oxygen and pH were monitored in two designated untreated 

("control") systems, per system type, at each sampling interval, rather than in the treated 

systems taken for analysis (p. 21). To establish that aerobic conditions were maintained 

throughout the study, system parameters should be monitored in the treated systems taken for 

extraction and analysis. 

5. All samples from a given treatment were connected to the same set of volatiles traps (p. 21). The 

reported concentrations of CO2 and other volatile compounds were adjusted based on the 

number of samples at the time of sampling (Appendix 4, pp. 109-110). It is preferred that 

sample vessels be connected to individual volatiles traps so that more precise material balances 

for each sample can be calculated. 

IV. References 

1. U.S. Environmental Protection Agency. 2008. Fate, Transport and Transformation Test -

Guidelines, OPPTS 835.4300, Aerobic Aquatic Metabolism. Office of Prevention, Pesticides 

and Toxic Substances, Washington, DC. EPA 712-C-08-018. 

1. U.S. Environmental Protection Agency. 2012. NAFTA Guidance for Evaluating and Calculating 

Degradation Kinetics in Environmental Media. 
Profenofos (PC 111401) MRID 48934901 

Page 22 of 31 

DER ATTACHMENT 1. Profenofos and Its Environmental Transformation Products. 

A

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR (study length) 

PARENT

Profenofos 

(CGA15324, 

CS_13269) 

IUPAC: (RS)-(O-4-bromo-2-chlorophenyl O-ethyl S-propyl 

phosphorothioate)

CAS: O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl 

phosphorothioate

CAS No.: 41198-08-7 Formula: C11

H15BrClO3PS 

MW: 373.63 g/mol

SMILES: CCCSP(=O)(OCC)Oc1ccc(Br)cc1Cl

835.4300 

Aerobic 

aquatic 

metabolism 

48934901 

Pond 

water/loamy 

sand 

sediment 

104.5% (0 d) ND (100 d)

Pond 

water/sand 

sediment 

105.5% (0 d) 2.4% (100 d)

MAJOR (>10%) TRANSFORMATION PRODUCTS 

CGA55960 (CS_13266)

IUPAC: 4-Bromo-2-chlorophenolCAS: Phenol, 4-Bromo-2-

chloroCAS No.: 3964-56-5 

Formula: C

H6 BrClO 4

MW: 207.45 g/molSMILES: c1cc(c(cc1Br)Cl)O

835.4300 

Aerobic 

aquatic 

metabolism 

48934901 

Pond 

water/loamy 

sand 

sediment 

52.2% (7 d) ND (100 d)

Pond 

water/sand 

sediment 

61.4% (14 d) 1.4% (100 d)

CGA19941 (CS_13259)

IUPAC: 4-Bromophenol CAS: Phenol, 4-Bromo 

835.4300 

Aerobic 

aquatic 

metabolism 

48934901 

Pond 

water/loamy 

sand 

sediment 

19.0% (48 d) 4.0% (100 d)
Profenofos (PC 111401) MRID 48934901 

Page 23 of 31 

Code Name/ 

Synonym Chemical Name Chemical Structure Study Type MRID Maximum %AR (day) Final %AR (study length) 

CAS No.: 106-41-2 Formula: C

H6 BrO 5

MW: 173.01 g/molSMILES: c1cc(ccc1O)Br

Pond 

water/sand 

sediment 

7.8% (28 d) 0.8% (100 d)

Carbon dioxide IUPAC: Carbon dioxide 

Formula: CO2MW: 44 g/molSMILES: C(=O)=O 

835.4300 

Aerobic 

aquatic 

metabolism 

48934901 

Pond 

water/loamy 

sand 

sediment 

29.1% (100 d) 29.1% (100 d)

Pond 

water/sand 

sediment 

36.5% (100 d) 36.5

% (100 d)

Unextractable residues

NA NA 

835.4300 

Aerobic 

aquatic 

metabolism 

48934901 

Pond 

water/loamy 

sand 

sediment 

16.3% (71 d) 14.2% (100 d)

Pond 

water/sand 

sediment 

18.1% (48 d) 11.9

% (100 d)

MINOR (<10%) TRANSFORMATION PRODUCTS

No minor transformation products were identified. 

REFERENCE COMPOUNDS NOT IDENTIFIED 

All compounds used as reference compounds were identified.

A AR means “applied radioactivity”. MW means “molecular weight”. ND means "not detected". 
Profenofos (PC 111401) MRID 48934901 

Page 24 of 31 

Attachment 2: Statistics Spreadsheets and Graphs 

Figure 1a. Transformation Kinetics of Profenofos in Total Pond Water:Loamy Sand Sediment 

System1, 2 

Profenofos in Loamy Sand Sediment System

DaysProfenofos

0

0

 0.5

 0.5

 1

 1

 3

 3

 7

 7

 14

 14

 28

 28

 48

 48

 71

 71

 100

 100

95.6

104.

81.2

75.9

81.2

65.6

52.2

50.1

42.2

43.9

26.7

30.0

21.1

20.0

13.5

11.8

6.50

4.20

0.00400

0.00400

0 20 40 60 80 100

0

20

40

60

80

100

Time

Concentration

SFO

DFOP

IORE

-20

-10

0

10

20

-20

-10

0

10

20

-20

-10

0

10

20

0 20 40 60 80 100

DT50 DT90

2 C0 Parameters

SFO 8.46 28.1 17 83.6 k 0.082

DFOP 3.34 49.5 4.8 98.7 f 0.477 k0 0.809 k1 0.0335

IORE 3.95 72.7 8.8 96.2 N 2.57 k 0.000243

SC

SSFO

Slow t1 2

tR IORE

 638

1.8e+03

20.7

21.9

1 Data were obtained from Table 9, p. 46 of the study report, with kinetics calculated by reviewer using R 8.4 (DER 

Attachment 2). 

2 Kinetics models: Simple First Order (SFO); Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 25 of 31 

Figure 1b. Transformation Kinetics of Profenofos in Total Pond Water:Sand Sediment 

System1, 2 

Profenofos in Sand Sediment System

DaysProfenofos

0

0

 0.5

 0.5

 1

 1

 3

 3

 7

 7

 14

 14

 28

 28

 48

 48

 71

 71

 100

 100

 106.

 103.

82.4

81.2

62.4

53.2

55.2

58.3

30.3

36.7

14.6

15.8

0.00400

3.00

2.00

2.50

4.70

3.60

0.00400

2.40

0 20 40 60 80 100

0

20

40

60

80

100

Time

Concentration

SFO

DFOP

IORE

-20

-10

0

10

20

-20

-10

0

10

20

-20

-10

0

10

20

0 20 40 60 80 100

DT50 DT90

2 C0 Parameters

SFO 4.51 15 18 89.2 k 0.154

DFOP 2.78 18.2 9.8 105 f 0.332 k0 2.41 k1 0.104

IORE 2.63 25 15 98.9 N 2.05 k 0.00316

SC

SSFO

Slow t1 2

tR IORE

1.08e+03

1.34e+03

6.65

7.53

1 Data were obtained from Table 12, p. 49 of the study report, with kinetics calculated by reviewer using R 8.4 (DER 

Attachment 2). 

2 Kinetics models: Simple First Order (SFO); Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 26 of 31 

Figure 2a. Transformation Kinetics of Profenofos Product CGA55960 in Total Pond 

Water:Loamy Sand Sediment System1, 2 

Product CGA55960 in Loamy Sand Sediment System

Days CGA55960

 7

 7

 14

 14

 28

 28

 48

 48

 71

 71

 100

 100

52.2

48.2

46.3

46.0

29.9

25.8

13.1

12.9

1.10

0.600

0.00400

0.00400

0 20 40 60 80 100

0

20

40

60

80

100

120

Time

Concentration

SFO

DFOP

IORE

-6

-4

-2

0

2

4

6

-6

-4

-2

0

2

4

6

-6

-4

-2

0

2

4

6

0 20 40 60 80 100

DT50 DT90

2 C0 Parameters

SFO 20 66.4 11 68.5 k 0.0347

DFOP 1.44 47.7 14 131 f 0.523 k0 0.0347 k1 3.73

IORE 25 61.5 6.6 62.3 N 0.585 k 0.134

SC

SSFO

Slow t1 2

tR IORE

67.3

 140

 20

18.5

1 Data were obtained from Table 9, p. 46 of the study report, with kinetics calculated by reviewer using R 8.4 (DER 

Attachment 2). 

2 Kinetics models: Simple First Order (SFO); Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 27 of 31 

Figure 2b. Transformation Kinetics of Profenofos Product CGA55960 in Total Pond 

Water:Sand Sediment System1, 2 

Product CGA55960 in Sand Sediment System

Days CGA55960

 14

 14

 28

 28

 48

 48

 71

 71

 100

 100

61.1

61.4

45.4

39.7

13.0

21.6

1.40

0.600

1.40

0.300 0 20 40 60 80 100

0

20

40

60

80

100

120

140

Time

Concentration

SFO

DFOP

IORE

-5

0

5

-5

0

5

-5

0

5

0 20 40 60 80 100

DT50 DT90

2 C0 Parameters

SFO 18.1 60 13 109 k 0.0384

DFOP 9.56 51.5 18 151 f 0.722 k0 0.0384 k1 2.03

IORE 24.2 60.1 7.1 91.2 N 0.601 k 0.152

SC

SSFO

Slow t1 2

tR IORE

 125

 203

18.1

18.1

1 Data were obtained from Table 12, p. 49 of the study report, with kinetics calculated by reviewer using R 8.4 (DER 

Attachment 2). 

2 Kinetics models: Simple First Order (SFO); Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 28 of 31 

Figure 3a. Transformation Kinetics of Profenofos Product CGA19941 in Total Pond 

Water:Loamy Sand Sediment System1, 2 

1 Data were obtained from Table 9, p. 46 of the study report, with kinetics calculated by reviewer using R 8.4 (DER 

Attachment 2). 

2 Kinetics models: Simple First Order (SFO); Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 29 of 31 

Figure 3b. Transformation Kinetics of Profenofos Product CGA19941 in Total Pond 

Water:Sand Sediment System1, 2 

1 Data were obtained from Table 12, p. 49 of the study report, with kinetics calculated by reviewer using R 8.4 (DER 

Attachment 2). 

2 Kinetics models: Simple First Order (SFO); Double First Order in Parallel (DFOP), and Indeterminate Order Rate 

Equation (IORE).
Profenofos (PC 111401) MRID 48934901 

Page 30 of 31 

Attachment 3: Calculations 

Calculations were performed by the reviewer using R software, and the following equations. 

Single First-Order (SFO) Model 

 (eq. 1) 

where, 

 Ct = concentration at time t (%) 

 C0 = initial concentration (%) 

e = Euler’s number (-) 

 k = SFO rate constant of decline (d-1) 

 t = time (d) 

The SFO equation is solved with R kinetics software by adjusting C0 and k to minimize the 

objective function (SSFO) shown in equation 9. 

DT50 = natural log (2)/k (eq. 2) 

DT90 = ln (10)/k (eq. 3) 

Indeterminate Order Rate Equation (IORE) Model 

 (eq. 4) 

where, 

 N = order of decline rate (-) 

 kIORE = IORE rate constant of decline (d-1) 

This equation is solved with R kinetics software by adjusting C0, kIORE, and N to minimize the 

objective function for IORE (SIORE) (See equation 9). Half-lives for the IORE model are 

calculated using equation 5, which represents a first-order half-life that passes through the DT90 of 

the IORE model. (Traditional DT50 and DT90 values for the IORE model can be calculated using 

equations 6 and 7.) 

 (eq. 5) 

DT50 = 

k(N -1)

(C /2) -C (1-N) 0 (1-N) 0

 (eq. 6) 

DT90 = 

k(N -1)

(C /10) -C (1-N) 0 (1-N) 0

 (eq. 7) 
Profenofos (PC 111401) MRID 48934901 

Page 31 of 31 

Double First-Order in Parallel (DFOP) Model 

 (eq. 8) 

where, 

 g = the fraction of C0 applied to compartment 1 (-) 

 k1 = rate constant for compartment 1 (d-1) 

 k2 = rate constant for compartment 2 (d-1) 

If C0 x g is set equal to a and C0(1-g) is set equal to c, then the equation can be solved with R 

kinetics software for a, c, k1, and k2 by minimizing the objective function (SDFOP) as described in 

equation 9. 

DT50 and DT90 values can be calculated using equations 2 and 3, with k1 or k2 in place of k. 

Objective Function: SFO, IORE, and DFOP are solved by minimizing the objective function (SSFO, 

SIORE, or SDFOP). 

 (eq. 9) 

where, 

SSFO , SIORE, or SDFOP = objective function of kinetics model fit (%2

) 

n = number of data points (-) 

Cmodel,t = modeled value at time corresponding to Cd,t (%) 

Cd,t = experimental concentration at time t (%) 

Critical Value to Determine Whether SFO is an Adequate Kinetics Model 

If SSFO is less than SC, the SFO model is adequate to describe kinetics. If not, the faster of tIORE or 

the DFOP DT50 for compartment 2 should be used. 

 (eq. 10) 

where, 

Sc = the critical value that defines the confidence contours (%2) 

p = number of parameters (3 in this case) 

α = the confidence level (0.50 in this case)

F(α, p, n-p) = F distribution with α level of confidence and degrees of freedom p and n-p