Page 2 of 35

There are also ecological toxicity data gaps, and these studies are necessary since they are 

expected to potentially impact risk conclusions. The database for ecological toxicity of 

propazine is incomplete, as the following ecological data gaps exist for propazine:

• Avian Acute Oral with a Passerine Species (OCSPP Guideline 850.2100):

Acceptable acute avian acute oral toxicity data were not submitted for a passerine 

species exposed to propazine, which is now required under the 40 CFR Part 158 

data requirements. Though the available acute dose-based bobwhite quail study 

indicates propazine results in minimal mortality to upland game bird species,

effects on weight in all available avian studies indicate that propazine exposure 

adversely affects avian species. Passerine species may be more sensitive to this 

chemical as a result of their higher metabolic rate and differing metabolic 

pathways. An avian oral toxicity study is needed for a passerine species. A 

passerine study protocol should be submitted for review by the Agency prior to 

initiation of the study.

• Avian Reproduction Study (OCSPP Guideline 850.2300): Propazine exposure 

to bobwhite quail resulted in frank effects on female body weight gain at the 

lowest concentration tested in the available supplemental bobwhite quail study; 

therefore there is no endpoint available to evaluate potential risk from chronic 

exposure to avian species, including listed birds. Propazine exposure results in 

effects on weight in all acute, subacute and chronic studies available, thus this 

study is necessary for risk assessment.
Page 3 of 35

Problem Formulation for the Environmental Fate 

and Ecological Risk, Endangered Species, and 

Drinking Water Assessments in Support of the 

Registration Review of Propazine

(2-chloro-4,6-bis(isopropylamino)-s-triazine)

CAS Registry Number: 139-40-2

PC Code: 080808

Prepared by:

Brian Kiernan, Biologist

Reuben Baris, Environmental Scientist

U. S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch VI

1200 Pennsylvania Ave., NW

Mail Code 7507P

Washington, DC 20460

Reviewed by:

William P. Eckel, Senior Science Advisor

Nathan Miller, Biologist

Mark Corbin, Branch Chief

May 08, 2013

N

N

N

N

H

CH3

N CH3 H

CH3

H3C

Cl

Office of Chemical Safety 

and Pollution Prevention
Page 4 of 35

Contents

1. Introduction..................................................................................................................5

2. Conclusions from Previous Risk Assessments............................................................5

2.1. Ecological Risk Assessments.............................................................................. 5

2.2. Drinking Water Exposure Assessments............................................................... 6

2.3. Clean Water Act Programs................................................................................... 6

3. Environmental Fate and Transport..................................................................................7

3.1. Degradation and Metabolism ............................................................................... 8

3.2. Transport and Mobility......................................................................................... 9

3.3. Field Studies......................................................................................................... 9

3.4. Review of Published Literature on the Environmental Fate of Propazine......... 10

3.5. Transformation Products.................................................................................... 10

4. Receptors....................................................................................................................11

4.1. Effects to Aquatic Organisms ............................................................................ 12

4.2. Effects to Terrestrial Organisms ........................................................................ 13

4.3. Ecological Incidents........................................................................................... 15

5. Exposure Pathways of Concern .................................................................................16

Risk Hypothesis................................................................................................................16

6. Analysis Plan ................................................................................................................16

6.1. Stressors of Concern........................................................................................... 16

6.2. Measures of Exposure ....................................................................................... 17

6.3. Measures of Effect ............................................................................................. 17

6.4. Endangered Species Assessments...................................................................... 17

6.5. Endocrine Disruptor Screening Program ........................................................... 18

7. Preliminary Identification of Data Gaps................................................................ 18

7.1. Environmental Fate................................................................................................ 18

7.2. Effects.................................................................................................................... 20

8. References.....................................................................................................................24
Page 5 of 35

1. Introduction

EFED evaluated the most recent ecological risk assessments for propazine in association 

with the updated toxicity, exposure, and usage information to determine if sufficient data 

are available and if further updates are needed to support registration review. Recent risk 

assessments include a risk assessment supporting the new use assessment for sorghum

(USEPA, 2006). In addition, EFED considered the latest Agency science policies and 

risk assessment methodologies.

Propazine (2-chloro-4,6-bis(isopropylamino)-s-triazine) is in the Weed Science Society 

herbicide group 5 (s-triazine) with the mechanism of action of inhibiting photosynthesis 

in photosystem II (PSII). Propazine is applied preemergence in grain sorghum (Sorghum 

bicolor) plantings in order to control broadleaf and grass weeds. The chemical profile 

provided by EPA’s Biological and Economic Affects Division (BEAD), located in the 

docket, lists the use patterns of maximum exposures for the currently registered uses of 

propazine. EFED will use application scenarios for sorghum that will result in potential

high-end exposure for the risk assessment. 

2. Conclusions from Previous Risk Assessments

2.1. Ecological Risk Assessments

The Agency has conducted previous ecological risk assessments for Propazine that serve 

as a basis for this scoping document. These assessments are briefly summarized below.

The most recent risk assessment for Propazine is the 2006 Section 3 new use registration 

for use to control weed in sorghum (DP barcodes (DP Barcodes 310326, 249944, and 

249945). The major ecological conclusions presented in these risk assessments were as 

follows:

Table 1. Summary of Risk Concerns Identified for Propazine in Previous Assessments

Bird

s

Mammal

s

Terr.

Plants

Terr.

Inverts Fish

BC

F

Aquati

c 

Inverts

Aquati

c 

Plants

Groundwater 

Contaminatio

n

Persistenc

e

Degradate

s of 

Concern

-- a √ b √ -- -- -- √ b √ c √ -- none d

a

 No chronic data b

 Chronic c

 Listed vascular species; all nonvascular. d

 2-hydroxypropazine was not considered of toxicological concern.
Page 6 of 35

2.2. Drinking Water Exposure Assessments

The latest Tier II drinking water exposure assessment for the proposed new use on 

sorghum was conducted for Propazine in 2006 (USEPA, 2006; D334595). This 

assessment was completed as an addendum to the drinking water exposure assessment 

conducted previously for the triazine cumulative dietary risk assessment. The addendum 

represented an additional drinking water exposure assessment for the principal sorghum 

growing areas of Kansas, Oklahoma, Texas, Colorado, and New Mexico that were not 

included in the triazine cumulative risk assessment. The previous drinking water 

assessment for the triazine cumulative risk assessment focused on surface water exposure 

scenarios in the Midwest, California and Florida for simazine, atrazine, and the chloro 

degradates of both (i.e., DEA (2-amino-4-chloro-6-(1-methylethylamino)-s-triazine) and 

DACT (2-chloro-4,6-diamino-1,3,5-triazine)). Propazine was not included in the original 

cumulative assessment because at the time it was conducted the only registered use was 

on greenhouse-grown ornamental plants, and there were no outdoor uses registered at the 

time of the assessment. The recent addition of a registration for propazine use on 

sorghum required consideration of a new exposure scenario because the principal 

sorghum growing area is outside the geographic extent of the three use areas previously 

considered in the cumulative assessment. Modeling was completed using both the Texas 

and Kansas sorghum scenarios for propazine use on sorghum, atrazine use on sorghum, 

and atrazine use on corn. Daily time series data were provided to the Health Effects 

Division in concert with daily output for atrazine modeling for use in the dietary models 

used to assess human exposure through consumption of drinking water in the dietary risk 

assessment. For risk assessment as part of registration review, the drinking water 

assessment for propazine will be revisited and it will be determined if an updated 

assessment is needed. 

2.3. Clean Water Act Programs

Propazine is not identified as a cause of impairment for any water bodies listed as 

impaired under section 303(d) of the Clean Water Act1. No Total Maximum Daily Load 

(TMDL) criteria have been developed for propazine. Aquatic benchmarks have been 

established for propazine and are available at 

http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm. Any data 

submitted or otherwise located as part of the registration review process may be used to 

update aquatic life benchmarks if applicable. 

 1 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885
Page 7 of 35

3. Environmental Fate and Transport

Environmental fate studies reviewed suggest that propazine is moderately persistent and 

mobile. If applied in an outdoor environment, propazine has a high potential to leach into 

ground water or reach surface waters by runoff. In areas where the soils are highly 

permeable, the water table is shallow, and sufficient precipitation and/or irrigation occur, 

the use of propazine may result in ground water contamination. Table 2 below 

summarizes the physical and chemical properties of propazine.

Table 2. Physical and Chemical Properties of Propazine

Common name Propazine

Chemical name CAS: 6-chloro-N,N’-bis(1-methylethyl)-1,3,5-

triazine-2,4-diamine

IUPAC: 2-chloro-4,6-bis(isopropylamino)-s-triazine

CAS number 139-40-2

Chemical Structure

Molecular formula C9H16ClN5

Molecular weight 229.71

Physical state Crystal

Melting point 212-214°C

Vapor pressure 2.9 x 10-8 mm Hg at 20°C

Water solubility 8.6 mg/L water at 20°C

Henry's Law Constant 1.02 x 10-9 atm.m3/mol (calculated)

Log Kow 2.91

pKa 1.85 at 22°C

Propazine is expected to be moderately persistent and mobile in most soils, and it is 

resistant to breakdown by hydrolysis, photolysis, or biodegradation. Batch equilibrium 

experiments suggest that propazine is mobile, with Freundlich Kd values ranging from 

0.67 to 3.19 in two separate studies involving 8 soil textures. The Koc values ranged from 

65 to 268 in these same studies. The mobility of propazine is also noted in the 

supplemental terrestrial field dissipation studies suggesting that propazine dissipates 

slowly from the upper 6 inches (half-lives of 51 days in TX, and 7 to 58 days in NC, <30 

to 149 days in NY, <31 days in CA, and 60 to >357 days in NE) and may leach to ground 

water. It has also been reported in the literature that if released to soil, propazine will 

persist longer in dry or cold conditions or other conditions which inhibit biological and 

chemical activity (Worthing, C.R., ed., 1983. “The pesticide manual: A world 

compendium. Croydon, England: The British Crop Protection Council”). Therefore, it is 

very likely that the use of propazine may result in groundwater and/or surface water 

contamination in areas where soils are highly permeable, the water table is shallow, or 

where there is irrigation and/or high rainfall. Volatility and air photolysis are not 

expected to be major routes of dissipation due to the low vapor pressure (2.9 x 10-8 torr at 

20oC). Table 3 below summarizes the environmental fate and transport properties of 

propazine.
Page 8 of 35

Table 3. Summary of Environmental Fate and Transport Properties for Propazine

Parameter Value Reference (MRID #)

Persistence in Water

Hydrolysis half-life (25°C, pH 5, 7, & 9) Stable 43689802

Aqueous photolysis half-life (25°C) Stable 44184805

Aerobic aquatic metabolism half-life (20oC) 120 days 48125802

Anaerobic aquatic metabolism half-life (20oC) 121 days 48125803

Persistence in Soil

Soil photolysis half-life (25°C) Stable 44184806

Aerobic soil metabolism half-life (20°C) 289 Days (sandy loam, pH 6.8) 

12-24 Weeks (calculated 15 wks; loamy 

sand soil, pH 5.6)

44184807

00153712

Anaerobic soil metabolism half-life (20oC) 8 Weeks (loamy sand soil) 00153713

Mobility

Organic carbon partitioning coefficient (KOC, 

L·kg-1/Kd)

83/0.34 (loamy sand); 

123/1.14 (sandy loam); 

158/2.69 (loam); 

65/3.19 (clay loam)

00152997

268.0.67 (sand); 

128/1.28 (sandy loam); 

96/1.30 (silty clay); 

79/1.35 (loam)

43689804

2-hydroxy-propazine

145/1.45 (sandy loam); 

329/0.28 (sand); 

78/1.33 (loam); 

342/4.57 (silty clay)

44287313

Field Dissipation

Terrestrial field dissipation half-life NC (Wilson Co) 1.2 lb ai/A - bare ground 

sandy loam (0-6") and sandy clay loam (6-

12")

t 1⁄2 = 7.2 days (1-21 days)

t 1⁄2 = 58.2 days (28-184 days)

44287314

TX (Armstrong Co) 1.2 lb ai/A - bare 

ground loamy sand (0-6" and 6-12")

T 1⁄2 = 52 days (186-day study)

44184809

3.1. Degradation and Metabolism

Existing laboratory studies indicate that propazine is stable to hydrolysis and photolysis 

(both aqueous and in soils). However, published literature on propazine and related 

chloro-s-triazines indicate that the chemical may be susceptible to hydrolysis after 

adsorption onto the surface of soil colloids (a surface catalysis effect). Propazine is 
Page 9 of 35

persistent under laboratory aerobic soil conditions with half-lives ranging from 15 weeks 

in loamy sand soil to 41 weeks in sandy loam soil. The major soil metabolite was 2-

hydroxy propazine (2-hydroxy-4,6-bis(isopropylamino)-s-triazine) and comprised a 

maximum of 31% of the total applied radioactivity (TAR) after one year. Minor 

degradates consist of desethylatrazine (2-chloro-4-isopropylamino-6-amino-s-triazine or 

DEA) (<2% of TAR) and 2-hydroxy desethylatrazine (<5% of TAR). No studies were 

submitted on the fate of any degradates (both major and minor) in the environment. 

Chemical structures of propazine degradates are presented below in Table 4. 

3.2. Transport and Mobility

Propazine is not likely to volatilize from near surface soils or surface waters under 

normal environmental conditions, due to its low vapor pressure (2.9 x 10-8 torr at 20°C). 

If released to water, propazine is not expected to bioconcentrate in aquatic organisms

(KOW = 2.93 using the experimental database in EPISuite 4.1), adsorb to sediment and/or 

suspended particulate matter, or to volatilize. 

Propazine does not adsorb as strongly to soil particles as other triazine herbicides. In 

most soils used in batch equilibrium studies, especially sand and sandy loam soils, it 

binds weakly to soil particles (Koc’s ranging from 83 to 268 L/kg oc). Literature studies 

also showed that depending on soil temperature, moisture, and pH, propazine can become 

unbound (Worthing, 1983). The major degradate, 2-hydroxy propazine is slightly less 

mobile, with Koc values ranging from 78 (loam) to 342 (silty clay) L/kg oc. In sand and 

sandy loam soils, the Koc values are 329 and 145 mL/g, respectively.

3.3. Field Studies

The four submitted field studies were either unacceptable or considered supplemental 

because of inadequate sampling depths (only the upper 12 inches were sampled), lack of 

frozen storage stability data (some samples were frozen for up to 3 years), and/or the 

presence of propazine in the control and treated plots prior to the start of the study. 

Supplemental data suggest that propazine, applied as a wettable powder at 2.4 to 4.8 lb 

a.i./A/yr, dissipated from the upper 6 inches with a half-life of <30 to 149 days in NY, 

<31 days in CA, and 60 to >357 days in NE. The degradates hydroxy-propazine, G28273 [2-chloro-4,6-diamino-s-triazine], and G-30033 [2-chloro-4-amino-6-

isopropylamino-s-triazine] were detected in one or more of the field studies (NY, CA, 

NE).

The major laboratory soil degradate, 2-hydroxy propazine was seen in the 0-3" and 3-6" 

soil layers of the terrestrial field studies at approximately 15% of parent at day 1, and 

decreased to less than 5% of parent by day 93. The other two minor degradates 

desethylatrazine (DEA) and 2,4-diamino-6 chloro-s-triazine (DACT), which are common 
Page 10 of 35

to atrazine and simazine, were detected only in the 0-3" soil layer, each at less than 5% of 

parent at day 1, however decreasing to less than 1% by day 28.

3.4. Review of Published Literature on the Environmental 

Fate of Propazine

The environmental fate of propazine in published scientific literature is limited and 

published studies vary in quality and usually contain insufficient information on 

procedures or raw data to adequately assess the results. However, these research findings 

can provide supplemental information on the environmental fate of propazine. The 

following discussion comes primarily from three published reviews - Khan (1980), 

Montgomery (1993), and Wolfe et al (1990) - which summarize several published 

studies.

Propazine, like the other triazine chemicals, is weakly basic (pKa 1.85 at 22°C; 

Montgomery, 1993), can be easily protonated at low soil pH values, and is likely to exist 

as a neutral species at soil pH values more than two pH units above the pKa (Koshinen 

and Harper, 1990). Adsorption of protonated propazine is pH-dependent, with a 

maximum adsorption at or near the pKa (Khan, 1980). Soil organic matter plays an 

important role in the adsorption of propazine and other s-triazines, affecting their 

movement in soil (Hayes, 1970).

The chemical hydrolysis of s-triazines, including propazine, is catalyzed by surface 

adsorption on soil colloids (Khan, 1980; Wolfe et al, 1991). Studies by Russell et al 

(1968), Brown and White (1969), and Nearpass (1972) found evidence that the chemical 

hydrolysis of propazine was catalyzed by adsorption onto organic matter and clay.

Montgomery (1993) summarized soil adsorption data from four studies (Burkhard and 

Guth, 1981; Harris, 1966; Talbert and Fletchall, 1965; Walker and Crawford, 1970) 

involving 38 soils. The reported adsorption Kd values averaged 3.4 mL/g, with a range of 

0.1 to 20.5. In 35 of the 38 soils, the Kd values were less than 4.7. The Koc values 

averaged 155 mL/g (ranging from 29 to 363), which are within the range of the Koc

values reported in the above mentioned environmental fate studies submitted by the 

registrant. 

3.5. Transformation Products

Table 4 lists the major and minor transformation products reported in the submitted 

environmental fate studies.
Page 11 of 35

Table 4. Major Transformation Products in Submitted Environmental Fate Studies

Parent

Propazine: (2-chloro-4,6-bis(isopropylamino)-striazine)

Formula: C9H16ClN5

Molecular Weight: 229.71

Degradates in Registrant-submitted Parent Fate Studies

Propazine degradate: DEA (desethylatrazine), 

(2-amino-4-chloro-6-(1-methylethylamino)-striazine)

Synonyms: Propazine des-ethyl (G-30033)

Formula: C6H10Cl N5

Molecular Weight: 187.63

Common chlorotriazine degradate

Equal toxicity to parent

Included in TRED

Propazine degradate: DACT (2-chloro-4,6-

diamino-1,3,5-triazine)

Synonym: G-28273

Formula: C3H4ClN5

Molecular Weight: 145.55

Common chlorotriazine degradate

Equal toxicity to parent

Included in TRED

Propazine degradate: 2-hydroxyprozpazine (2-

hydroxy-4,6-bis-(1-methylethylamino)-striazine)

Synonym: GS-11526

Formula: C9H17N5OH

Molecular Weight: 211.26

Different toxicity compared to parent, exposure 

considered to be lower therefore was not 

included in TRED.

4. Receptors

Table 5 and Table 6 provide a summary of the most sensitive aquatic and terrestrial 

acute and chronic endpoints that will be used in the risk assessment. In addition, the 

tables provide a preliminary overview of the potential acute toxicity of propazine by 

providing the acute toxicity classifications. There are no submitted data on the potential 

toxicity of the degradates on either aquatic or terrestrial organisms.

N

N

N

N

H

CH3

N CH3 H

CH3

H3C

Cl

N

N

N

Cl

N2H NH CH

CH3

CH3

N

N

N

Cl

N2H NH2

N

N

N

CH NH NH

C3H

C3H

CH

CH3

CH3

OH
Page 12 of 35

4.1. Effects to Aquatic Organisms

Although the LC50s for aquatic fish and invertebrates are near or above the solubility of 

propazine, sublethal effects (such as loss of equilibrium) were observed in all the acute 

studies at concentrations similar to those where effects are observed in the chronic 

exposure studies.

Studies for all four taxa of nonvascular aquatic plants have been submitted; while the 

most sensitive endpoint is shown, other taxa are affected at similar concentrations. Data 

on the degradate desethylatrazine are available for three cyanobacteria and two green 

algae; these data indicate this degradate is less toxic than propazine parent. Growth of 

the aquatic vascular plant, Lemna gibba, is also inhibited by exposure to propazine.

In previous assessments, 2-hydroxypropazine was not considered as a degradate of 

concern for ecological assessment. However, ECOSAR, a structural activity relationship 

modeling program, suggests that 2-hydroxypropazine has similar toxicity to the parent 

propazine. Given the lack of study data on this degradate, the assumption of equivalent 

toxicity will be employed in the risk assessment.

The aquatic effects dataset for propazine is largely complete and further data are not 

being requested at this time.

Table 5. Summary of the Most Sensitive Endpoints from Aquatic Toxicity Studies for 

Propazine.

Taxonomic 

Group

Study 

Type

Surrogate Species Toxicity Value Acute 

Toxicity 

Classification 

Source

(Study 

classification)

Freshwater fish1

Acute

Bluegill Sunfish

(Lepomis 

macrochirus)

LC50 >4.38 mg

ai/L

Moderately

toxic

48036203

(Acceptable)

Chronic 

(Early 

LifeStage)

Fathead Minnow 

(Pimephales 

promelas)

NOAEC = 0.56

mg ai/L

LOAEC = 1.23

mg ai/L

Endpoint:

reduction in 

growth

-- 48036205

(Acceptable)

Freshwater 

invertebrates

Acute Water Flea 

(Daphnia magna)

EC50 > 5.32 mg 

ai/L

Moderately 

toxic

44287305

(Supplemental)

Chronic Water Flea 

NOAEC = 

0.047 mg ai/L

LOAEC = 0.091

mg ai/L

Endpoint: 

reduction in 

growth

--

44327602

(Acceptable)
Page 13 of 35

Taxonomic 

Group

Study 

Type

Surrogate Species Toxicity Value Acute 

Toxicity 

Classification 

Source

(Study 

classification)

Estuarine/marine 

fish

Acute

Sheepshead 

Minnow 

(Cyprinodon 

variegatus)

LC50 >3.87 mg 

ai/L

Moderately 

toxic

48036204

(Acceptable)

Chronic 

(36 day)

Sheepshead 

Minnow 

(Cyprinodon 

variegatus)

NOAEC = 1.34 

mg ai/L

LOAEC = 2.59 

mg ai/L

Endpoint: 

embryo survival 

and hatching 

success

-- 44184802

(Supplemental)

Estuarine/marine 

invertebrates

Acute

Mysid

(Americamysis 

bahia)

LC50 = 4.2 mg 

ai/L

Moderately 

toxic

44184801

(Acceptable)

Chronic 

(28 day)

Mysid 

(Americamysis 

bahia)

NOAEC = 

0.266 mg ai/L

LOAEC = 0.474

mg ai/L

Endpoint: 

reduction in 

growth 

-- 48125801

Aquatic plants

Vascular Duckweed 

(Lemna gibba)

NOAEC = 

0.022 mg ai/L

IC50 =0.1 mg 

ai/L

-- 44287309

(Acceptable)

Nonvascular

Freshwater diatom

(Navicula 

pelliculosa)

NOAEC = 

0.0065 mg ai/L

IC50 = 0.0248

mg ai/L

-- 44287310

(Acceptable)

1 Freshwater fish may be surrogates for aquatic-phase amphibians.

4.2. Effects to Terrestrial Organisms

Propazine is classified as practically nontoxic to terrestrial birds from acute dose-based or 

dietary-based exposure; however, an acute oral study for a passerine species is not 

available for propazine. Sublethal effects (decreased weights) were noted in both the 

bobwhite quail and the mallard duck acute oral and subacute dietary studies, suggesting 

chemical-induced anorexic responses. Additionally, adult female weight gain was 

significantly affected in both mallard duck and bobwhite quail reproduction studies, with 

significant effects at the lowest dose in the bobwhite study. Therefore, an avian NOAEC 

is unavailable for the risk assessment. Effects on avian weight are also evident in studies 

with both simazine and atrazine, chemicals closely related to propazine.

Propazine is classified as practically nontoxic to mammals on an acute exposure basis, 

but effects from chronic exposure (adult toxicity and reproduction effects) were observed 

as low as 50 mg ai/kg-bw/day. Propazine is classified as practically nontoxic to 
Page 14 of 35

honeybees. As expected with an herbicide, propazine adversely affects plants. Effects 

were seen in both the seedling emergence studies and in both monocots and dicots. For 

some species in these studies, NOAECs were not determined; in these cases the EC05 will 

be used to estimate risk to listed plant species.

The following ecological data gaps exist for propazine:

• Avian Acute Oral with a Passerine Species (OCSPP Guideline 850.2100):

Acceptable acute avian acute oral toxicity data were not submitted for a passerine 

species exposed to propazine, which is now required under the 40 CFR Part 158 

data requirements. Though the available bobwhite quail study indicates propazine 

results in minimal mortality to upland game bird species, effects on weight in all 

available avian studies indicate that propazine exposure adversely affects avian 

species. Passerine species may be more sensitive to this chemical as a result of 

their higher metabolic rate and differing metabolic pathways. An avian oral 

toxicity study is needed for a passerine species. A passerine study protocol 

should be submitted for review by the Agency prior to initiation of the study.

• Avian Reproduction Study (OCSPP Guideline 850.2300): Propazine exposure 

to bobwhite quail resulted in frank effects on female body weight gain at the 

lowest concentration tested in the available study; therefore there is no endpoint 

available to evaluate potential risk from chronic exposure to avian species, 

included listed birds. Propazine exposure results in effects on weights in all 

acute, subacute and chronic studies available, thus this study is necessary for risk 

assessment.

Table 6. Summary of the Most Sensitive Endpoints from Terrestrial Toxicity Studies for 

Propazine

Taxonomic 

Group

Study 

Type

Surrogate 

Species

Toxicity Value Acute 

Toxicity 

Classification

Source 

(Study 

classification)

Birds

Acute

Bobwhite quail

(Colinus 

virginianus)

LD50 > 1640 mg

ai/kg-bw

Practically 

non-toxic

44287301

(Acceptable)

Sub-acute 

dietary

Mallard duck

(Anas 

platyrhynchos)

LC50 > 4930 mg

ai/kg-diet

Practically 

non-toxic

44287302

(Acceptable)

Chronic Bobwhite quail

NOAEC <262 mg

ai/kg-diet

LOAEC = 262 mg

ai/kg-diet

Endpoint: adult 

female body weight 

gain

-- 48036201

(Supplemental)

Mammals Acute Oral

Laboratory rat 

(Rattus 

norvegicus)

LD50 > 5050 mg

ai/kg-bw

Practically 

non-toxic

43474101

(Acceptable)
Page 15 of 35

Taxonomic 

Group

Study 

Type

Surrogate 

Species

Toxicity Value Acute 

Toxicity 

Classification

Source 

(Study 

classification)

Chronic

Laboratory rat 

(Rattus 

norvegicus)

NOAEL = 5 mg

ai/kg/day

LOAEL = 50 mg

ai/kg/day

Endpoint: parental

toxicity and 

reproductive effects

-- 00041409

(Acceptable)

Insects Acute 

contact

Honey bee 

(Apis mellifera)

LD50 > 96.7 μg

ai/bee

Practically 

non-toxic

00036935

(Supplemental)

Terrestrial 

plants

Seedling 

Emergence

Dicot (Lettuce; 

Lactuca sativa)

IC25 > 0.16 lb/A

NOAEC= 0.0047 

lbs ai/A

--

44184804

Monocot (Acceptable)

(Onion; Allium 

cepa)

IC25 > 0.35 lb ai/A

IC05= 0.0087 lbs 

ai/A

--

Vegetative 

Vigor

Dicot 

(Cucumber; 

Cucumis sativa)

IC25 = 0.046 lb ai/A

NOAEC = 0.020 lb 

ai/A

--

44184804

Monocot (Acceptable)

(Wheat; Titicum 

aestivum)

IC25 = 0.10 lb ai/A

IC05= 0.047 lbs 

ai/A

--

4.3. Ecological Incidents

The ecological incident information system (EIIS) is an OPP database that houses 

ecological incidents that have been reported to the Agency. When available, EIIS 

includes date and location of an incident, type and magnitude of effects observed in 

various species, use(s) of pesticides known or suspected of contributing to the incident, 

and results of any chemical residue analysis or other analyses conducted during incident 

investigation. EIIS incidents are categorized according to the certainty that the incident 

resulted from pesticide exposure. The Avian Monitoring System (AIMS) is a database 

administered by the American Bird Conservancy that contains publicly available data on 

reported avian incidents involving pesticides. Many of the incidents listed in this 

database are also in the EIIS. Further, some incidents may be reported as ‘aggregate 

incidents’; these are contained in a separate database.

As of 02/06/2013, there were no reported incidents in EIIS or the aggregate incident 

databases for propazine (Robert Miller, EISB; pers. comm.). However, incidents have 

been reported with other chemicals in the triazine class, such as simazine and atrazine. 

These chemicals have been more widely used for a longer period of time than propazine, 

which may help explain the lack of incidents for propazine. The absence of reported 

incidents should not be construed as the absence of incidents. Incident reports for nontarget organisms typically provide information only on mortality events and plant 

damage. Sublethal effects in organisms such as abnormal behavior, reduced growth 
Page 16 of 35

and/or impaired reproduction are rarely reported, except for phytotoxic effects in 

terrestrial plants. EPA’s changes in the registrant reporting requirements for incidents in 

1998 may account for a reduced number of reported incidents. Registrants are now only 

required to submit detailed information on ‘major’ fish, wildlife, and plant incidents. 

Minor fish, wildlife, and plant incidents, as well as all other non-target incidents, are 

generally reported aggregately and are not included in EIIS. In addition, there have been 

changes in state monitoring efforts due to a lack of resources.

As of 02/13/2013, AIMS identified no ecological incidents involving propazine and no 

aggregate incidents have been reported. 

5. Exposure Pathways of Concern

The environmental fate and toxicity profile for propazine suggests that direct spray, spray 

drift, leaching and runoff represent the likely exposure pathways for terrestrial and 

aquatic non-target organisms. Drinking water and inhalation exposure pathways were 

screened using the SIP (Screening Imbibition Program) and STIR (Screening Tool for 

Inhalation Risk) screening methods and were found to be exposure pathways of low 

concern (no LOC exceedances are expected). SIP and STIR are described in detail at: 

http://www.epa.gov/oppefed1/models/terrestrial/index.htm.

Risk Hypothesis

The Registration Review ecological risk assessment will test the following risk 

hypothesis:

Based on the application methods, mode of action, fate and transport, and the 

sensitivity of non-target aquatic and terrestrial species, propazine has the potential to 

reduce survival, reproduction, and/or growth in non-target terrestrial and aquatic 

organisms as well as negatively affect the structure, productivity, and function of 

aquatic plant communities when used in accordance with the current labels. These 

non-target organisms include Federally-listed threatened and endangered species as 

well as non-listed species.

6. Analysis Plan

6.1. Stressors of Concern

Propazine is part of the triazine herbicide family (such as atrazine, cyanazine, simazine) 

and is very effective at stopping the photosynthetic process in susceptible plants by 

binding to specific sites within the plant's chloroplasts. The mode of action is inhibition

of photosynthesis by stopping electron flow in Photosystem II, which in turn inhibits the 

formation and release of oxygen. 
Page 17 of 35

In previous assessments, 2-hydroxypropazine was not considered as a degradate of 

concern for ecological assessment. However, ECOSAR, a structural activity relationship 

modeling program, suggests that 2-hydroxypropazine has similar toxicity to the parent 

propazine. Given the lack of study data on this degradate, the assumption of equivalent 

toxicity will be employed in the risk assessment.

Drinking Water 

The drinking water assessments conducted to support future human health risk 

assessments of Propazine will incorporate model estimates of Propazine residues of 

concern, which are the parent compound and the major degradates DEA and DACT in 

surface water and groundwater. If a drinking water assessment is needed to support 

future human health dietary risk assessments propazine and its degradates of concern will 

be assessed at the time of the assessment. 

6.2. Measures of Exposure 

EFED will use standard available models to evaluate potential exposures to aquatic and 

terrestrial organisms as described at 

http://www.epa.gov/pesticides/science/models_db.htm.

6.3. Measures of Effect 

Toxicity data presented in Section 3 of this problem formulation will be used to calculate 

risk quotients. Any additional information submitted by the registrant or found in the 

open literature prior to conduct of the risk assessment will also be considered. The open 

literature studies are identified using EPA’s ECOTOXicology database (ECOTOX) 

(USEPA, 2007c), which employs a literature search engine for locating chemical toxicity 

data for aquatic life, terrestrial plants, and wildlife. The evaluation of both sources of 

data can also provide insight into the direct and indirect effects of pesticides on biotic 

communities from loss of species that are sensitive to the chemicals and from changes in 

structure and functional characteristics of the affected communities.

6.4. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), 

the Agency will evaluate risks to federally listed species from registered uses of 

pesticides in registration review. The process for evaluating potential risks to listed 

species is further described at 

http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm.
Page 18 of 35

6.5. Endocrine Disruptor Screening Program

Propazine was not included in the first group of 67 chemicals issued an order to conduct 

Tier 1 EDSP testing. For additional information the EDSP program, visit 

http://www.epa.gov/endo/. 

7. Preliminary Identification of Data Gaps 

7.1. Environmental Fate

The database for environmental fate and transport of propazine is sufficient for risk 

assessment as part of registration review. Although there are a few guidelines that are 

only partially fulfilled, additional fate data are not being requested for registration review 

because they are unlikely to significantly impact the risk assessment. Unfulfilled 

guidelines are outlined below.

• Aerobic aquatic metabolism (OCSPP Guideline 835.4300): There is uncertainty 

associated with the extrapolated half-lives from one of the soil:water systems. An 

additional soil:water system is needed to fulfill the guideline; however, it is of low 

additional value since the single value is considered persistent, it is unlikely an 

additional study would significantly change the overall persistence profile.

• Anaerobic aquatic metabolism (OCSPP Guideline 835.4400): There is 

uncertainty associated with the extrapolated half-lives from one of the soil:water 

systems. An additional soil:water system is needed to fulfill the guideline; however, 

it is of low additional value since the single value is considered persistent, it is 

unlikely an additional study would significantly change the overall persistence 

profile.

• Terrestrial Field Dissipation (OCSPP Guideline 835.6100): An acceptable study 

is needed to fulfill the guideline; however, Additional studies are unlikely to provide 

significantly different results for risk assessment. 

Table 7 catalogues the environmental fate studies by MRID that offer data for each 

guideline requirement, as well as study classifications identifying whether additional data 

are needed in order to support risk assessment.

Table 7. Submitted Environmental Fate Data for Propazine

Guideline Study Title MRID Classification Data Gap? Comments and Assumption EPA will make in 

absence of additional data.

835.2120 Hydrolysis

43689802 Acceptable

No

--

00153708 Unacceptable

No material balance was provided. Radiolabeled test 

substances were not characterized. Sterility was 

assumed but not reported.

835.2240 Photodegradation 44184805 Acceptable No --
Page 19 of 35

Guideline Study Title MRID Classification Data Gap? Comments and Assumption EPA will make in 

absence of additional data.

in Water

00153709 Supplemental

Inadequate experimental conditions were reported. 

Missing crucial information such as pH, temperature, 

wavelength of light source, inadequate descriptions 

of experimental conditions.

835.2410 Photodegradation 

on Soil

44184806 Acceptable

No

--

00153710 Unacceptable

Experimental design was inadequate to accurately 

assess photodegradation. Study was not conducted 

for a sufficient length of time.

835.4100 Aerobic Soil 

Metabolism

44184807 Acceptable

No -- 00153712 Acceptable

835.4200 Anaerobic Soil 

Metabolism 00153713 Acceptable No --

835.4300 Aerobic Aquatic 

Metabolism 48125802 Supplemental Yes

The study was terminated prior to clearly 

establishing the rate and pattern of decline of 

propazine and formation and decline of all 

degradates. There is uncertainty associated with the 

extrapolated half-lives. Unassigned peaks were 

present in the chromatographs and transformation 

products present at ≥10% of the applied may not 

have been identified.

An additional soil:water system is needed to fulfill

the guideline; however, it is of low additional value.

835.4400 Anaerobic Aquatic 

Metabolism 48125803 Supplemental Yes

The study was terminated prior to clearly 

establishing the rate and pattern of decline of 

propazine and formation and decline of degradates. 

There is uncertainty associated with the extrapolated 

half-lives.

An additional soil:water system is needed to fulfill 

the guideline; however, it is of low additional value.

835.1240

Mobility - 

Adsorption / 

Desorption

43689803 Acceptable

No -- 43689804 Acceptable

44287313 Acceptable

00152997 Acceptable

835.6100 Terrestrial Field 

Dissipation 

44287314 Supplemental

Yes

Stated in 2006 NU assessment on Sorghum (USEPA, 

2006; DP 310326+): Data classified as supplemental. 

Additional data, or a new study, needed to confirm 

leaching potential of compound. Lack of storage 

stability data and propazine was found in controls is 

problematic.

Additional studies are unlikely to provide 

significantly different results for risk assessment; 

however, it is of low additional value.

44184809 Supplemental

00153715 Unacceptable

00153716 Unacceptable

00153717 Unacceptable

00153718 Unacceptable

835.6100

Terrestrial Field 

Dissipation/Small 

Scale Prospective 

Ground Water

44184808 Supplemental No

Study was submitted to partially satisfy 835.6100 and 

substitute for a Small Scale PGW study. Mass 

balance was poor toward the termination of the 

study. Rainfall and irrigation for the first 30-60 days 

following pesticide application were not favorable to 

leaching.
Page 20 of 35

Guideline Study Title MRID Classification Data Gap? Comments and Assumption EPA will make in 

absence of additional data.

850.1730 Fish Accumulation 44184812 Acceptable No

In a cursory review of a dynamic or flow-through 

aquatic exposure study using bluegill sunfish, the 

daily bioconcentration factors (BCFs) of Propazine 

were reported to range from 6.51 to 20.2 for the 

whole fish, indicating that it does not bioaccumulate 

to any great extent.

Environmental 

Chemistry Method 

(water)

46839502 Acceptable No --

Environmental 

Chemistry Method 

(Soil)

00065585 Acceptable No --

Monitoring Studies

47990302 Supplemental

No

Perez, S.; Perez, R.; Chen, S.; et al. (2010) FIFRA 

Section 6(a)(2) Annual Report for Atrazine, 

Simazine, Propazine, G-28273, G-28279, G-30033, 

Ametryn, GS-11354, GS-11355, GS-26831 and 

Metolachlor Monitoring Data for Surface Water 

Samples Collected in the 2009 Atrazine Monitoring 

Program, 2009 Atrazine Ecological Monitoring 

Program, 2009 Simazine Monitoring Program, 2009 

Simazine Confirmatory Monitoring Program and 

2009 Stewardship Voluntary Monitoring Program: 

Final Report. Project Number: 2K10/901/0223S/01, 

T001301/03. Unpublished study prepared by ADPEN 

Laboratories, Inc. 31 p.

48402903 Supplemental

Perez, S.; Perez, R.; Chen, S.; et al. (2011) FIFRA 

Section 6(a)(2) Annual Report for Atrazine, 

Metolachlor, Propazine, Simazine, DACT, DIA and 

DEA Monitoring Data for Surface Water Samples 

Collected in the 2010 Atrazine Monitoring Program, 

2010 Atrazine Ecological Monitoring Program, 2010 

Simazine Monitoring Program, 2010 Simazine 

Confirmatory Monitoring Program and 2010 

Stewardship Voluntary Monitoring Program: Final 

Report. Project Number: 2K11/901/0223S/01, 

T001301/03. Unpublished study prepared by ADPEN 

Laboratories, Inc. 27 p.

47639601 Supplemental

Tweedy, D.; Perez, S. (2009) Triazine Water

Monitoring Progam in Four Texas Community Water 

Supplies (2008): Analytical Report. Project Number: 

2K8/ADPEN/ALB/PWM/001, 

ADPEN/2K8/ALB/PWM. Unpublished study 

prepared by ADPEN Laboratories, Inc. 59 p.

00155231 Supplemental

Ross, R.; Balu, K. (1985) Summary of the Propazine 

Surface Water Monitoring for 1975: Rept. No. EIR85019. Unpublished study prepared by Ciba-Geigy 

Corp. 56 p.

7.2. Effects

Table 9 and Table 10 identify ecological effects studies by MRID that provide data for 

each guideline requirement, as well as study classifications and whether or not further 

data are needed in order to support risk assessment. The effects data for propazine is 
Page 21 of 35

largely complete; however, the following data gaps need to be addressed to conduct the 

risk assessment:

• Avian Acute Oral with a Passerine Species (OCSPP Guideline 850.2100):

Acceptable acute avian acute oral toxicity data were not submitted for a passerine 

species exposed to propazine, which is now required under the 40 CFR Part 158 

data requirements. Though the available bobwhite quail study indicates Propazine 

results in minimal mortality to upland game bird species, effects on weight in all 

available avian studies indicate that propazine exposure adversely affects avian 

species. Passerine species may be more sensitive to this chemical as a result of 

their higher metabolic rate and differing metabolic pathways. An avian oral 

toxicity study is needed for a passerine species. A passerine study protocol 

should be submitted for review by the Agency prior to initiation of the study.

• Avian Reproduction Study (OCSPP Guideline 850.2300): Propazine exposure 

to bobwhite quail resulted in frank effects on female body weight gain at the 

lowest concentration tested in the available study; therefore there is no endpoint 

available to evaluate potential risk from chronic exposure to avian species, 

included listed birds. Propazine exposure results in effects on weights in all 

acute, subacute and chronic studies available, thus this study is necessary for risk 

assessment.

Table 9. Submitted Aquatic Ecological Effects Data for Propazine

OCSPP

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed to 

conduct 

risk 

assessment?

Justification and 

Assumptions EPA will 

Make in Absence of Data

850.1010 Freshwater 

invertebrate 

acute toxicity

44287305 Supplemental No --

850.1025

850.1035

Estuarine/Marine 

invertebrate 

acute toxicity 

44184801 Acceptable No --

850.1075 Freshwater fish 

acute toxicity 

48036203 Acceptable No --

850.1075 Estuarine/Marine 

fish acute 

toxicity 

48036204 Acceptable No --

850.1300 Freshwater 

invertebrate 

life cycle 

443327602 Acceptable No --
Page 22 of 35

OCSPP

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed to 

conduct 

risk 

assessment?

Justification and 

Assumptions EPA will 

Make in Absence of Data

850.1350 Estuarine/Marine

invertebrates 

life cycle 

48125801 Acceptable No --

850.1400 Freshwater fish 

early-life stage

48036205 Acceptable No --

850.1400 Estuarine/Marine

fish 

early-life stage 

44184802 Supplemental No --

850.1500 Fish life cycle (None) (N/A) No --

850.4400 Aquatic plant 

growth:

Tier II vascular 

plants

44287309 Acceptable No --

850.5400 Aquatic Plant 

Growth:

Tier II algae

44287308 Acceptable No --

44207310 Acceptable 

44287311 Acceptable

44287312 Acceptable

Table 10. Submitted Terrestrial Ecological Effects Data for Propazine

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed for 

risk 

assessment?

Current Additional Data 

Need

850.2100 Avian oral 

toxicity

44287301 Acceptable Yes Acceptable acute avian 

acute oral toxicity data 

have not been submitted 

for a passerine species 

exposed to propazine, 

which is now required 

under the 40 CFR Part 158 

data requirements. A 

passerine study protocol 

should be submitted for 

review by the Agency 

prior to initiation of the 

study. 
Page 23 of 35

OCSPP 

Guideline

Data 

Requirement

Submitted 

Studies 

(MRID)

Study 

Classifications

Are data 

needed for 

risk 

assessment?

Current Additional Data 

Need

850.2200 Avian dietary 

toxicity 

44287302 Acceptable No --

44287303 Acceptable

850.2300 Avian 

reproduction

48036202 Acceptable Yes No endpoint available to 

assess potential risk from 

chronic exposure 48036201 Supplemental

850.3020 Honey bee 

acute contact 

toxicity

00036935 Supplemental No --

850.3030 Honey bee 

residue on 

foliage

(None) (N/A) No --

850.3040 Field testing 

for 

pollinators

(None) (N/A) No --

850.4100 Terrestrial 

plant toxicity:

seedling 

emergence

44184804 Acceptable No --

850.4150 Terrestrial 

plant toxicity:

vegetative 

vigor

44184804 Acceptable No --
Page 24 of 35

8. References 

Hayes, M.H.B. 1970. Adsorption of triazine herbicides on soil organic matter, including 

a short review of soil organic matter chemistry. Residue Rev. 31:131-174.

Khan, Shahamat U. 1980. Pesticides in the soil environment. Elsevier Scientific 

Publishing Company, Amsterdam. p. 90-97.

Koskinen, W.C., and S.S. Harper. 1990. The retention process: mechanisms. p. 51-77 

In H.H. Cheng (ed.) Pesticides in the soil environment: processes, impacts, and 

modeling. SSSA Book Series No. 2. Soil Science Society of America, Madison, WI.

Montgomery, J.H. 1993. Agrochemicals desk reference: environmental data. Lewis 

Publishers, Chelsea, MI. p. 356-358.

USEPA 2006. Ecological Risk Assessment for the Section 3 New Use on Sorghum: 

Propazine. DP barcodes 310326, 249944, 249945. United States Environmental 

Protection Agency, Office of Pesticide Programs, Washington, DC. 

USEPA 2006. Addendum to the Environmental Fate and Effects Division (EFED) 

Drinking Water Exposure Assessment for the Addition of Propazine Use on Sorghum to 

the Triazine Cumulative Dietary Risk Assessment (DP 334595). Memorandum from M. 

Corbin to C. Eiden. United States Environmental Protection Agency, Office of Pesticide 

Programs, Environmental Fate and Effects Division, Washington, DC.

Wolfe, N.L., U. Mingelgrin, and G.C. Miller. 1990. Abiotic transformations in water, 

sediments, and soil. p. 103-168 In H.H. Cheng (ed.) Pesticides in the soil environment: 

processes, impacts, and modeling. SSSA Book Series No. 2. Soil Science Society of 

America, Madison, WI.
Page 25 of 35

080808 Propazine Eco Effects Bibliography

Green Folder- F001122

71-1 Avian Single Dose Oral Toxicity

MRID Citation Reference

111696 2041111 Beliles, R.; Scott, W.; Knott, W. (1965) ?Propazine: Toxicity 

to Fish and Wildlife|. (Unpublished study received Aug 23, 

1965 under 100-455; prepared by Woodard Research Corp., 

submitted by Ciba-Geigy Corp., Greensboro, NC; 

CDL:132115-A) 

44287301 2041117 Jameson, C.; Veltri, J. (1995) Acute Oral Toxicity of 

Propazine to Bobwhite Quail (Colinus virginianus): Final 

Report: Lab Project Number: 41757: FIFRA-71-1-AT-41757: 

ABC 41757. Unpublished study prepared by ABC Labs, Inc. 

338 p. 

71-2 Avian Dietary Toxicity

MRID Citation Reference

34121 2041113 Woodard Research Corporation (1965) Propazine: Safety 

Evaluation on Fish and Wildlife (Bobwhite Quail, Mallard 

Ducks, Rainbow Trout, Goldfish and Sunfish). (Unpublished 

study received Oct 4, 1965 under 100-455; submitted by CibaGeigy Corp., Greens- boro, N.C.; CDL:000333-A) 

34122 2041105 Woodard Research Corporation (19??) Propazine: Subacute 

Toxicity in Mallard Ducks. (Unpublished study received Oct 

4, 1965 under 100-455; submitted by Ciba-Geigy Corp., 

Greensboro, N.C.; CDL: 000333-B) 

34126 2041108 Beliles, R.P.; Scott, W.; Knott, W. (1965) Propazine: 

Summary of Safety Evaluation on Fish and Wildlife. Summary 

of studies 000333-A through 000333-E. (Unpublished study 

received Oct 4, 1965 under 100-455; prepared by Woodard 

Research Corp., submit- ted by Ciba-Geigy Corp., Greensboro, 

N.C.; CDL:000333-F) 

44287302 2041118 Jameson, C.; Veltri, J. (1994) Acute Dietary Toxicity of 

Propazine to Bobwhite Quail (Colinus virginianus): Final 

Report: Lab Project Number: 41758: FIFRA-71-2-AT-41758: 

ABC 41758. Unpublished study prepared by ABC Labs, Inc. 

189 p. 

44287303 2041119 Jameson, C.; Veltri, J. (1995) Acute Dietary Toxicity of 
Page 26 of 35

Propazine to Mallard Duck (Anas platyrhynchos): Final 

Report: Lab Project Number: 41759: FIFRA-71-2-AT-41759: 

ABC 41759. Unpublished study prepared by ABC Labs, Inc. 

201 p. 

71-4 850.2300 Avian Reproduction

MRID Citation Reference

48036201 Contract draft 

available

Stafford, J. (2009) Propazine: Reproductive Toxicity Test with 

Northern Bobwhite (Colinus virginianus). Project Number: 

13905/4100. Unpublished study prepared by Springborn 

Smithers Laboratories. 237 p.

48036202 Contract draft 

available

Stafford, J. (2009) Propazine: Reproductive Toxicity Test with 

the Mallard Duck (Anas platyrhynchos). Project Number: 

13905/4101. Unpublished study prepared by Springborn 

Smithers Laboratories. 245 p.

72-1 850.1075 Acute Toxicity to Freshwater Fish

MRID Citation Reference

111696 2041111 Beliles, R.; Scott, W.; Knott, W. (1965) ?Propazine: Toxicity 

to Fish and Wildlife|. (Unpublished study received Aug 23, 

1965 under 100-455; prepared by Woodard Research Corp., 

submitted by Ciba-Geigy Corp., Greensboro, NC; 

CDL:132115-A) 

44287304 2041120 Bowman, J.; Veltri, J. (1995) Acute Toxicity of Propazine to 

Bluegill (Lepomis macrochirus): Final Report: Lab Project 

Number: 41953: FIFRA 72-1: ABC 41953. Unpublished study 

prepared by ABC Labs, Inc. 58 p. 

47452301 DER not 

located

Bergfield, A. (2008) Propazine: Acute Toxicity to the 

Rainbow Trout, Onchorhynchus mykiss, Determined Under 

Static Test Conditions. Project Number: 63222. Unpublished 

study prepared by ABC Laboratories, Inc. 30 p.

48036203 Contract draft 

available

Bergfield, A. (2009) Propazine: Acute Toxicity to the Bluegill 

Sunfish, Lepomis macrochirus, Determined Under FlowThrough Test Conditions. Project Number: 64353. 

Unpublished study prepared by ABC Laboratories, Inc. 42 p.

34123 2041114 Woodard Research Corporation (1949) Propazine: Acute 

Toxicity in Rainbow Trout. (Unpublished study received Oct 

4, 1965 under 100-455; submitted by Ciba-Geigy Corp., 
Page 27 of 35

Greensboro, N.C.; CDL: 000333-C) 

34124 2041115 Woodard Research Corporation (1949) Propazine: Acute 

Toxicity in Sunfish. (Unpublished study received Oct 4, 1965 

under 100-455; submitted by Ciba-Geigy Corp., Greensboro, 

N.C.; CDL:000333-D) 

34125 2041112 Woodard Research Corporation (1949?) Propazine: Acute 

Toxicity in Goldfish. (Unpublished study received Oct 4, 1965 

under 100- 455; submitted by Ciba-Geigy Corp., Greensboro, 

N.C.; CDL: 000333-E) 

Acute Toxicity to Freshwater Invertebrates

MRID Citation Reference

44287305 2048016 Murrell, H.; Veltri, J. (1994) Acute Toxicity of Propazine to 

Daphnia magna: Final Report: Lab Project Number: 41954: 

FIFRA 72-2: 41954R. Unpublished study prepared by ABC 

Labs, Inc. 187 p. 

850.1075 Acute Toxicity to Estuarine/Marine Organisms

MRID Citation Reference

44184801 Contract draft 

available

Boeri, R.; Kowalski, P.; Ward, T. (1995) Static Acute Toxicity 

of Propazine to the Mysid, Mysidopsis bahia: (Final Report): 

Lab Project Number: 41955: 571-AB. Unpublished study 

prepared by T.R. Wilbury Labs., Inc. and ABC Labs., Inc. 45 

p. 

44287306 2041121 Boeri, R.; Kowalski, P.; Ward, T. (1995) Flow Through Shell 

Deposition Test with Propazine and the Eastern Oyster, 

Crassostrea virginica: (Final Report): Lab Project Number: 

41956: 572-AB: FIFRA-72-3 © F/T. Unpublished study 

prepared by T.R. Wilbury Labs, Inc. and ABC Labs, Inc. 146 

p. 

48036204 Contract draft 

available

Berfield, A. (2009) Propazine: Acute Toxicity to the 

Sheepshead Minnow, Cyprinodon 27egetative, Determined 

Under Flow-Through Test Conditions. Project Number: 

64352. Unpublished study prepared by ABC Laboratories, Inc. 

44 p.

111682 DER not 

located

Wright, L.; Beliles, R. (1966) Propazine: The Effect on Shell 

Growth in Oysters. (Unpublished study received Jan 7, 1968 

under 8F0687; prepared by Woodard Research Corp., 
Page 28 of 35

submitted by Geigy Chemical Corp., New York, NY; 

CDL:091195-M) 

Fish Early Life Stage/Aquatic Invertebrate Life Cycle Study

850.1350 Mysid chronic toxicity test

850.1400 Fish early-life stage toxicity test

MRID Citation Reference

23999 2041106 Walker, C.R. (1964) Simazine and other~s~Triazine 

compounds as aquatic herbicides in fish habitats. Weeds 

12(2):134-139. (Al- so~In~unpublished submission received 

Mar 8, 1966 under 100-437; submitted by Ciba-Geigy Corp., 

Greensboro, N.C.; CDL:100918-S) 

34126 Summary of 

studies

Beliles, R.P.; Scott, W.; Knott, W. (1965) Propazine: 

Summary of Safety Evaluation on Fish and Wildlife. Summary 

of studies 000333-A through 000333-E. (Unpublished study 

received Oct 4, 1965 under 100-455; prepared by Woodard 

Research Corp., submit- ted by Ciba-Geigy Corp., Greensboro, 

N.C.; CDL:000333-F) 

44184802 Contract draft 

available

Boeri, R.; Kowalski, P.; Ward, T. (1995) Early Life-Stage 

Toxicity of Propazine to the Sheepshead Minnow, Cyprinodon 

28egetative: (Final Report): Lab Project Number: 41959: 574-

AB: FIFRA-72-4-SHM. Unpublished study prepared by T.R. 

Wilbury Labs., Inc. and ABC Labs., Inc. 59 p. 

44184803 Contract draft 

available

Boeri, R.; Kowalski, P.; Ward, T. (1995) Chronic Toxicity of 

Propazine to the Mysid, Mysidopsis bahia: (Final Report): Lab 

Project Number: 41960: 573-AB: FIFRA-72-4-M. 

Unpublished study prepared by T.R. Wilbury Labs., Inc. and 

ABC Labs., Inc. 65 p. 

44287307 2041122 Rhodes, J.; Veltri, J. (1995) Early Life-Stage Toxicity of 

Propazine to the Fathead Minnow (Pimephales promelas) 

Under Flow-Through Conditions: Final Report: Lab Project 

Number: 41957: ABC 41957: FIFRA 72-4-FHM. Unpublished 

study prepared by ABC Labs, Inc. 236 p. 

44327601 2041128 Veltri, J.; Bussard, J. (1995) Analytical Analysis of Propazine 

During the “Early Life-Stage Toxicity Test with the 

Sheepshead Minnow (Cyprinodon 28egetative)”: Amended 

Final Report: Lab Project Number: 41959: 574-AB: ABC 

41959. Unpublished study prepared by ABC Labs, Inc. and T. 

R. Wilbury Labs, Inc. 285 p. 

44327602 2041129 Murrell, H.; Veltri, J. (1997) Chronic Toxicity of Propazine to 
Page 29 of 35

Daphnia magna Under Flow-Through Test Conditions: 

Amended Final Report: Lab Project Number: 41958: FIFRA 

E-72-4-B: ABC 41958. Unpublished study prepared by ABC 

Labs, Inc. 135 p. 

48125801 Contract draft 

available

Hicks, S. (2010) Propazine: Life-Cycle Toxicity Test of the 

Saltwater Mysid, Americamysis bahia, Conducted Under 

Flow-Through Conditions. Project Number: 65491. 

Unpublished study prepared by ABC Laboratories, Inc. 81 p.

48036205 Contract draft 

available

Lehman, C. (2009) Propazine: Early Life-Stage Toxicity Test 

with the Fathead Minnow, Pimephales promelas, Under FlowThrough Test Conditions. Project Number: 64354. 

Unpublished study prepared by ABC Laboratories, Inc. 85 p.

Seed germination/seedling emergence and Vegetative vigor

MRID Citation Reference

44184804 2084836 = 

SE- Contract 

draft

2084837 

=VVg 

Contract draft

Schwab, D.; Lee, B.; Veltri, J. (1996) Evaluating the Effects of 

Propazine on the Emergence and Vegetative Vigor of NonTarget Terrestrial Plants: Final Report: Lab Project Number: 

41961: GP95-037: ACFS-41961.EV. Unpublished study 

prepared by ABC Labs., Inc. 204 p. 

Aquatic plant growth

MRID Citation Reference

44287308 2041123 Hicks, S.; Bussrad, J.; Gledhill, D. (1995) Acute Toxicity of 

Propazine to Selenastrum capricornutum Printz: Final Report: 

Lab Project Number: 41962: FIFRA 123-2(A): ABC 41962. 

Unpublished study prepared by ABC Labs, Inc. 258 p. 

44287309 2041124 Hicks, S.; Gledhill, D.; Veltri, J. (1995) 14-Day Static Toxicity 

of Propazine to Lemna gibba G3: Final Report: Lab Project 

Number: 41963: ABC 41963. Unpublished study prepared by 

ABC Labs, Inc. 41 p. 

44287310 2041125 Hicks, S.; Gledhill, D. (1995) Acute Toxicity of Propazine to 

Navicula pelliculosa: Amended Final Report: Lab Project 

Number: 41966: FIFRA 123-2(A): ABC 41966. Unpublished 

study prepared by ABC Labs, Inc. 336 p. 

44287311 2041126

2048015

Gledhill, D.; Bussard, J. (1995) Acute Toxicity of Propazine to 

Skeletonema costatum: Final Report: Lab Project Number: 
Page 30 of 35

41967: FIFRA 123-2(A): ABC 41967. Unpublished study 

prepared by ABC Labs, Inc. 316 p. 

44287312 2041127 Gledhill, D.; Bussard, J. (1995) Acute Toxicity of Propazine to 

Anabaena flos-aquae: Final Report: Lab Project Number: 

41968: FIFRA 123-2(A): ABC 41968. Unpublished study 

prepared by ABC Labs, Inc. 284 p. 

24005 Sounds like 

published lit

Fankhauser, E. (1967) A Comparison of Chlorotriazines in 

Their Algicaedal Activity. (Unpublished study received Aug 

28, 1975 under 100-437; prepared by J.R. Geigy, S.A., 

submitted by Ciba- Geigy Corp., Greensboro, N.C.; 

CDL:221042-D) 

28137 Open lit Venkataraman, G.S.; Rajyalakshmi, B. (1972) Relative 

tolerance of nitrogen-fixing blue-green algae to pesticides. 

Indian Journal of Agricultural Science 42(2):119-121. 

(Also~In~unpublished submission received Aug 20, 1976 

under 39445-1; submitted by American Carbonyl, Inc., 

Tenafly, N.J.; CDL:228229-AI) 

114888 Open lit Venkataraman, G.; Rajyalakshmi, B. (1971) Tolerance of bluegreen algae to pesticides. Current Science 40(6):143-144. 

(Also In unpublished submission received Mar 18, 1976 under 

464-402; sub- mitted by Dow Chemical U.S.A., Midland, MI; 

CDL:095213-Q) 

Simulated or Actual Field Testing

MRID Citation Reference

23999 2041106 Walker, C.R. (1964) Simazine and other~s~Triazine 

compounds as aquatic herbicides in fish habitats. Weeds 

12(2):134-139. (Al- so~In~unpublished submission received 

Mar 8, 1966 under 100-437; submitted by Ciba-Geigy Corp., 

Greensboro, N.C.; CDL:100918-S) 

141-1 Acute Toxicity to Honeybees

36935 2041109 Atkins, E.L., E.A. Greywood and R.L. Macdonald (1975) 

Toxicity of Pesticides and other Agricultural Chemicals to 

Honey Bees. Laboratory Studies. University of California, 

Div. of Agric. Sci. Leaflet 2287. 38 pp.

Non Guideline

75705 Open lit Holly, K.; Roberts, H.A. (1963) Persistence of phytotoxic 

residues of triazine herbicides in soil. Weed Research 3(? ):1-

10. (Al- so in unpublished submission received Jul 19, 1978 
Page 31 of 35

under 201- 403; submitted by Shell Chemical Co., 

Washington, D.C.; CDL: 234476-AI) 

48033010 Open lit Nishihara, T.; Nishikawa, J.; Kanayama, T.; et al. (2000) 

Estrogenic Activities of 517 Chemicals by Yeast Two-Hybrid 

Assay. Journal of Health Science 46(4): 282-298.

5007255 2041107 Hilton, H.W. and N. Nomura (1964) phytotoxicity of 

Herbicides as Measured by Root Absorption. Weed Research 

4(3): 216-222. MRID No. 5007255.

18144 2041110 E.I. du Pont de Nemours and Company (1967) Biological 

Data. (Unpublished Study Received November 21, 1967 

under 352-270. CDL: 002882-A.)

Propazine Fate Chemistry Bibliography

835.2120 Hydrolysis

MRID Citation Reference

00153708 Burkhard, N. (1977) Hydrolysis of Propazine under 

Laboratory Con- ditions: Project Rept. No. 33/77. Unpublished 

study prepared by Ciba-Geigy Ltd., Basle. 16 p. 

43689802 Perdue, D. (1994) Hydrolysis of (carbon 14)-Propazine in 

Aqueous Buffered Solutions at pH 5, 7, and 9: Lab Project 

Number: 850: 1640. Unpublished study prepared by PTRL 

East, Inc. 72 p. 

835.2240 Photodegradation-water

MRID Citation Reference

00153709 Halama, P.; Balu, K.; Hofberg, A. (1972) Photolysis of 

Propazine in Aqueous Solution under Natural and Artificial 

Sunlight Condi- tions: Rept. No. GAAC-72116. Unpublished 

study prepared by Ciba-Geigy Corp. 10 p. 

44184805 Mobley, S. (1994) Solution Photolysis of (carbon-14) 

Propazine in Artificial Light: Lab Project Number: 851: 1644. 

Unpublished study prepared by PTRL East, Inc. 89 p. 

835.2410 Photodegradation-soil

MRID Citation Reference
Page 32 of 35

00153710 Burkhard, N. (1979) Photolysis of Propazine (Gesamil) on Soil 

Sur- faces under Artificial Sunlight Conditions: Project Rept. 

No. 03/79. Unpublished study prepared by Ciba-Geigy Ltd., 

Basle. 14 p. 

44184806 Mobley, S. (1994) Soil Surface Photolysis of (carbon-14) 

Propazine in Artificial Light: Lab Project Number: 852: 1645. 

Unpublished study prepared by PTRL East, Inc. 87 p. 

835.4100 Aerobic soil metabolism

MRID Citation Reference

00153712 Keller, A. (1979) Degradation of Propazine (Gesamil) in 

Aerobic Soil: Project Rept. No. 15/79. Unpublished study 

prepared by Ciba-Geigy Ltd., Basle. 19 p. 

44184807 Perdue, D. (1995) Aerobic Soil Metabolism of (carbon-14) 

Propazine in Sandy Loam: Lab Project Number: 865: 1661. 

Unpublished study prepared by PTRL East, Inc. 125 p. 

835.4200 Anaerobic soil metabolism

MRID Citation Reference

00153713 Keller, A. (1979) Degradation of Propazine (Gesamil) in Soil 

Under Aerobic, Aerobic/Anaerobic and Sterile/Aerobic 

Conditions: Pro- ject Rept. No. 23/79. Unpublished study 

prepared by Ciba-Geigy Ltd.,Basle. 28 p. 

835.4300 Aerobic aquatic metab.

MRID Citation Reference

48125802 Habeeb, S. (2010) Propazine: Aerobic Transformation in 

Aquatic Sediment Systems. Project Number: 64355. 

Unpublished study prepared by ABC Laboratories, Inc. 127 p.

835.4400 Anaerobic Aquatic Metabolism

MRID Citation Reference

48125803 Habeeb, S.B. 201t), Propazine: Anaerobic transformation in 

aquatic sediment
Page 33 of 35

systems. Unpublished study performed by ABC Laboratories, 

Inc., Columbia, Missouri; sponsored and submitted by 

Albaugh, Inc., Valdosta, Georgia. ABC Study No.: 64356.

835.1240 Leach/adsorp/desorption

MRID Citation Reference

00152997 Warren, J. (1985) Determination of Adsorption/Desorption 

Constants of Propazine and GS-11526: ABC Report # 32641. 

Unpublished report prepared by Analytical Bio-Chemistry 

Laboratories, Inc. 59 p. 

43689803 Perdue, D. (1995) Column Leaching of (carbon 14)-Propazine 

in Four Soil Types Following Aerobic Aging: Lab Project 

Number: 855: 1660. Unpublished study prepared by PTRL 

East, Inc. 161 p. 

43689804 Perdue, D. (1995) Soil Adsorption/Desorption of (carbon 14)-

Propazine by the Batch Equilibrium Method: Lab Project 

Number: 853: 1653. Unpublished study prepared by PTRL 

East, Inc. 78 p. 

44287313 Perdue, D. (1995) Soil Adsorption/Desorption of 2-Hydroxy-

(carbon 14)Propazine by the Batch Equilibrium Method: (Final 

Report): Lab Project Number: 913: 1817. Unpublished study 

prepared by PTRL East, Inc. 75 p. 

835.6100 Terrestrial field dissipation

MRID Citation Reference

44184809 Hughes, D. (1996) Field Soil Dissipation of Propazine (MiloPro 4L) on Bare Soil in Texas: Final Report: Lab Project 

Number: 6641-100: CHW 6641-100. Unpublished study 

prepared by American Agricultural Services, Inc. and Corning 

Hazleton Inc. 277 p. 

44287314 Hughes, D. (1996) Field Soil Dissipation of Propazine (MiloPro 4L) on Bare Soil in North Carolina: Final Report: Lab 

Project Number: 6641-100A: CHW 6641-100A. Unpublished 

study prepared by American Agricultural Services, Inc. and 

Corning Hazleton, Inc. 276 p. 

153715 Honeycutt, R. (1985) Field Dissipation Studies on Propazine 
Page 34 of 35

(Milo- gard 80W) (Columbia, New York): Rept. No. EIR84021. Unpublish- ed studies prepared by Ciba-Geigy Corp. 

273 p. 

153716 Honeycutt, R. (1985) Field Dissipation Studies on Propazine 

(Milo- gard 80W) (Fresno, California): Rept. No. EIR-84025. 

Unpublish- ed study prepared by Ciba-Geigy Corp. 185 p. 

153717 Honeycutt, R. (1985) Field Dissipation Studies on Propazine 

(Milo- gard 80W) (York, Nebraska): Rept. No. EIR-84026. 

Unpublished study prepared by Ciba-Geigy Corp. 232 p. 

153718 Honeycutt, R. (1985) Field Dissipation Studies on Propazine 

(Milo- gard 80W) (Lubbock, Texas): Rept. No. EIR-84027. 

Unpublished study prepared by Ciba-Geigy Corp. 182 p. 

835.6100 Small Scale Prospective Groundwater

MRID Citation Reference

44184808 Lightle, S.; Coody, P. (1996) The Mobility and Degradation of 

(carbon-14) Propazine Utilizing Field Installed Lysimeters in a 

North Carolina Loamy Sand Soil: Lab Project Number: 901: 

1876: 107. Unpublished study prepared by PTRL East, Inc; 

PTRL South, Inc.; and A & L Great Lakes Labs., Inc. 344 p. 

850.1730 Bioaccumulation in fish

MRID Citation Reference

44184812 Jalali, K.; Forbis, A. (1996) Bioconcentration of (carbon-14) 

Propazine in Bluegill Sunfish Following Exposure in a FlowThrough System: Lab Project Number: 516W-1: 516W: 

516W/ABC 42167. Unpublished study prepared by PTRL 

West, Inc. and ABC Labs. 206 p. 

850.7100 Environmental Chemistry Guidelines

MRID Citation Reference

00065585 Mattson, A.M.; Kahrs, R.A.; Murphy, R.T. (1969) 

Quantitative Determination of Triazine Herbicides in 

Soils by Chemical Analysis: GAAC-69014. Method 
Page 35 of 35

dated Mar 18, 1969. (Unpublished study received Aug 

26, 1977 under 100-496; submitted by Ciba-Geigy 

Corp., Greensboro, N.C.; CDL:231423-B) 

46839502 ECM Review by USEPA Triazines in Water