UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MEMORANDUM 

Date: 25-FEB-2015 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

SUBJECT: Propoxycarbazone-sodium. Human Health Assessment Seeping Document and 

Preliminary Human Health Risk Assessment in Support of Registration Review. 

PC Code: 122019 

Decision No.: 496089 

Petition No.: N/ A 

Risk Assessment Type: Single Chemical/Aggregate 

TXRNo.: NA 

MRIDNo.: NA 

DP Barcode: 0423232 

Registration No.: N/ A 

Regulatory Action: Registration Review Risk Assessment 

Case No.: 7264 

CAS No.: 181274-15-7 (sodium salt); 

145026-81-9 (acid) 

40 CFR: § 180.600 

FROM: Sarah J. Levy, Chemist~() 1/}' / -·· .., Kelly M. Lowe, Environmental Stie~ YZ:~/ -- Monique M. Perron, Sc.D~~xi log~ '--uru- .:.U\fi-/--

Jaclyn Pyne, Biologist (/~ 

Risk Assessment Branch (RA 1) 

Health Effects Division (HED; 7509P) 

THRU: 

TO: Lata Venkateshwara!Avivah Jakob 

Pesticide Re-evaluation Division (PRD; 7508P) 

As part of Registration Review, PRD of the Office of Pesticide Programs (OPP) has requested 

that HED evaluate the hazard and exposure data and conduct occupational and residential 

exposure assessments, as needed, to estimate the risk to human health that will result from the 

currently registered uses of pesticides. This memorandum serves as HED's seeping document 

AND preliminary human health risk assessment of the dietary, occupational and residential 

exposure, and aggregate risk from the registered uses of propoxycarbazone-sodium (methyl 2-

[[[( 4,5-dihydro-4-methyl-5-oxo-3-propoxy-1 H-1 ,2,4-triazol-1-yl)carbonyl]amino ]sulfonyl] 

benzoate sodium salt). The most recent human health risk assessment was performed in 2008, 

and was for the use of propoxycarbazone-sodium on pasture and rangeland grasses (Memo, S. 

Levy et al., 1 0-DEC-2008; D34851 0). The following risk assessment updates have been made: 

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Propoxycarbazone-sodium Human Health Risk Assessment 0423232 

• Chronic dietary (food+ drinking water) exposure assessment to reflect revised estimated 

drinking water concentrations (EDWCs) using the Dietary Exposure Evaluation ModelFood Consumption Intake Database (DEEM-FCID, ver. 3.16) which incorporates 

consumption data from USDA NHANES/WWEIA (2003-2008); 

• Quantitative spray-drift exposure/risk assessment; and 

• Updates to HED's exposure policies/data, along with policy changes for body weight 

assumptions. 

A summary ofthe findings and an assessment of human risk resulting from the registered uses of 

propoxycarbazone-sodium are provided in this document. The risk assessment was provided by 

Sarah Levy (RAB 1 ), the dietary risk assessment and residue chemistry review were provided by 

Jackie Pyne (on detail to RAB 1 ), the occupational/residential exposure assessment was provided 

by Kelly Lowe (RAB 1 ), the hazard characterization was provided by Monique Perron (RAB 1 ), 

and the drinking water assessment was provided by James Lin of the Environmental Fate and 

Effects Division (EFED). 

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Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Table of Contents

1.0 Executive Summary ....................................................................................................................................... 4

2.0 Recommendations.......................................................................................................................................... 6

3.0 Ingredient Profile ........................................................................................................................................... 8

4.0 Hazard Identification/Toxicology .................................................................................................................. 9

5.0 Dietary Exposure and Risk Assessment....................................................................................................... 12

6.0 Residential (Non-Occupational) Exposure and Risk Assessment................................................................ 14

7.0 Aggregate Exposure and Risk Assessment.................................................................................................. 16

8.0 Cumulative Exposure/Risk Characterization ............................................................................................... 16

9.0 Occupational Exposure ................................................................................................................................ 17

10.0 Public Health and Pesticide Epidemiology Data ......................................................................................... 19

11.0 References.................................................................................................................................................... 19

Attachment 1: Chemical Identity Tables. ............................................................................................................... 20

Attachment 2: Propoxycarbazone-Sodium Acute, Subchronic, and Chronic Toxicity Profile............................... 22

Attachment 3: Registered Propoxycarbazone End Use Products and Use Patterns................................................ 26

Attachment 4: Chronic Dietary Exposure Files. ..................................................................................................... 27

Attachment 5: Propoxycarbazone-sodium IRLS Sheet........................................................................................... 29
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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1.0 Executive Summary

Propoxycarbazone-sodium is a selective postemergence herbicide belonging to the sulfonamide 

class of herbicides. There are currently three end-use products containing propoxycarbazonesodium that are registered by Bayer CropScience. It is formulated as a dry flowable (DF), and is 

currently registered for use in control of certain grasses and broadleaf weeds in wheat, triticale, 

and pastureland/rangeland. There are currently no registered special local needs (SLN) or 

Section 18 Emergency Exemptions, and no pending PRIA actions for propoxycarbazone-sodium. 

The most recent quantitative human health risk assessment was performed in 2008 in 

conjunction with the request for the use of propoxycarbazone-sodium on pasture and rangeland 

grasses (Memo, S. Levy et al., 10-DEC-2008; D348510). 

HED has evaluated the status of the human health risk assessments for propoxycarbazonesodium to determine whether sufficient data are available and whether any updates are needed to 

support Registration Review. Since the last human health risk assessment for 

propoxycarbazone-sodium, no new data have been submitted, and no changes have been made to 

the selected endpoints, toxicological points of departure (PODs), or recommended tolerances. 

This document incorporates changes made to HED policies, revised exposure and risk estimates, 

and a quantitative spray-drift exposure/risk assessment.

Hazard Assessment and Dose Response Assessment: The toxicology database for 

propoxycarbazone-sodium is complete to support Registration Review except for the subchronic 

inhalation study that is required in accordance with the current 40 CFR Part 158 Toxicology 

Data Requirements. However, the Hazard and Science Policy Council (HASPOC) concluded,

based on a weight-of-evidence approach, that this study is not required at this time (U. Habiba; 

18-NOV-2014; TXR#0057073). The endpoints, PODs, and safety factors (SFs) for 

propoxycarbazone-sodium from the most-recent human health risk assessment are considered 

protective of all effects seen in the database; however, updates were made to reflect current HED 

policy. For all exposure scenarios, a 100-fold uncertainty factor (UF) (10X for interspecies 

extrapolation, 10X for intraspecies variation, and 1X for Food Quality Protection Act (FQPA) SF

when applicable) was applied.

Residue Chemistry and Dietary Risk Estimates (Food + Drinking Water): The residue chemistry 

database is adequate to support current Registration Review data requirements. Adequate 

metabolism (crops, livestock, and rotational crops), storage stability, magnitude of the residue, 

and processing data are available to support the registered uses. Adequate methods are available 

for enforcement of the currently established tolerances. 

The dietary exposure database is adequate to support current Registration Review requirements. 

The chronic dietary exposure assessment was updated to reflect revised EDWCs using the 

Dietary Exposure Evaluation Model - Food Consumption Intake Database (DEEM-FCID, ver. 

3.16) which incorporates consumption data from USDA NHANES/WWEIA (2003-2008). The 

unrefined [tolerance-level residues, 100% crop treated (CT), DEEM (ver. 7.81) default 

processing factors, and modeled drinking water estimates] chronic dietary (food + drinking 

water) exposure estimates are below HED’s level of concern [LOC; <100% of the chronic 

population-adjusted dose (cPAD)] for the general U.S. population and all population subgroups 

(<1% of the cPAD). An acute dietary (food + drinking water) exposure and risk assessment was

not conducted for propoxycarbazone-sodium because an endpoint of concern attributable to a 

single oral dose was not selected for any population subgroup (including infants and children). 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Propoxycarbazone-sodium was classified as “not likely to be carcinogenic to humans”; therefore, 

a cancer dietary assessment was not performed.

Residential (Non-Occupational) Exposure and Risk Assessment: There are no proposed or

current registrations for products containing propoxycarbazone-sodium that allow residential use. 

Therefore, residential handler and conventional residential post-application exposure 

assessments were not conducted to support Registration Review. A quantitative spray-drift 

assessment was conducted. Risk estimates from groundboom and aerial applications are not of 

concern at the field edge for all scenarios considered. 

Aggregate-Risk Estimates: There is sufficient information available to assess aggregate 

exposure. In accordance with FQPA, HED must consider and aggregate pesticide exposures and 

risks from three major sources: food, drinking water, and residential exposures. An acute 

aggregate risk assessment was not performed because an endpoint of concern attributable to a 

single oral dose was not selected for any population subgroup (including infants and children). 

Short- and intermediate-term aggregate risk assessments were not performed because there are 

no registered residential non-food uses. A cancer aggregate risk assessment was not performed 

because propoxycarbazone-sodium is classified as “not likely to be carcinogenic to humans.” 

The chronic aggregate assessment consists of only of dietary sources; therefore, the exposure 

estimates provided in the dietary exposure analyses represent chronic aggregate exposure. 

Therefore, the chronic aggregate (food + drinking water) propoxycarbazone-sodium risk 

estimates do not exceed HED’s LOC. 

Occupational Exposure and Risk Assessment: The occupational exposure database is adequate 

to support the Registration Review process for propoxycarbazone-sodium. There is the potential 

for occupational exposure from the registered uses of propoxycarbazone-sodium. These uses 

have been assessed using the most up-to-date exposure policies and data available. Since no 

dermal hazard was identified, a quantitative dermal assessment was not conducted for the 

occupational uses of propoxycarbazone-sodium. The occupational handler exposure and risk 

estimates indicate that the short- and intermediate-term inhalation margins of exposure (MOEs)

do not exceed HED’s LOC (i.e., MOE > the LOC of 100).

Occupational post-application dermal exposure and risk estimates were not quantitatively 

assessed since a dermal hazard was not identified. Based on the Agency's current practices, a 

quantitative non-cancer occupational post-application inhalation exposure assessment was not 

performed for propoxycarbazone-sodium at this time. If new policies or procedures are put into 

place, then the Agency may revisit the need for a quantitative occupational post-application 

inhalation exposure assessment for propoxycarbazone-sodium. 

Environmental Justice Considerations: Potential areas of environmental justice concerns, to the 

extent possible, were considered in this human health risk assessment, in accordance with U.S. 

Executive Order 12898, “Federal Actions to Address Environmental Justice in Minority 

Populations and Low-Income Populations.”

Review of Human Research: This risk assessment relies in part on data from studies in which adult 

human subjects were intentionally exposed to a pesticide or other chemical. These data, which 

include studies from the Pesticide Handlers Exposure Database (PHED) 1.1 and the Agricultural 

Handler Exposure Task Force (AHETF) database are (1) subject to ethics review pursuant to 40 CFR 

26, (2) have received that review, and (3) are compliant with applicable ethics requirements. For 

certain studies, the ethics review may have included review by the Human Studies Review Board. 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Descriptions of data sources, as well as guidance on their use, can be found at the following Agency 

websites: http://www.epa.gov/pesticides/science/handler-exposure-data.html and 

http://www.epa.gov/pesticides/science/post-app-exposure-data.html. 

2.0 Recommendations

HED has examined the toxicology and residue chemistry databases for propoxycarbazonesodium. There are no residue chemistry, occupational/residential, or toxicology data deficiencies 

that would preclude the continuation of all registered uses and permanent tolerances for the 

combined residues of propoxycarbazone-sodium and its metabolite Pr-2-OH [methyl 2-[[[(4,5-

dihydro-3-(2- hydroxypropoxy)-4-methyl-5-oxo-1H-1,2,4-triazol-1-l)carbonyl]amino]sulfonyl]

benzoate] as outlined in Table 2.2.3.1. 

2.1 Data Deficiencies

There are no data deficiencies for propoxycarbazone-sodium.

2.2 Tolerance Considerations

2.2.1 Enforcement Analytical Method

For purposes of Registration Review, an adequate method is available for enforcing the current

grass, wheat, and livestock tolerances. The liquid chromatography/mass spectroscopy/mass 

spectroscopy (LC/MS/MS) enforcement method (Bayer Method No. 108817) is available for 

enforcing tolerances for residues of propoxycarbazone-sodium and its Pr-2-OH metabolite 

[methyl 2-[[[(4,5-dihydro-3-(2-hydroxypropoxy)-4-methyl-5-oxo-1H-1,2,4-triazol-1-

yl)carbonyl]amino]sulfonyl]benzoate], in/on wheat and livestock commodities. Although the 

method has been deemed acceptable, HED previously asked for clarification concerning the 

instructions to clearly state that propoxycarbazone-sodium as the free acid is the compound to be 

used for preparation of standard and fortification solutions. Furthermore, the petitioner defined 

MKH 6561 as both “propoxycarbazone-sodium” and “propoxycarbazone (acid)” (Memo, S. 

Levy, 25-SEP-2013; D412002). HED requests that these clarifications still be submitted.

The Pr-2-OH standard does not expire until 07-DEC-1019; however, the EPA National Pesticide 

Standard Repository has requested that the registrant send ~1 gram to the Repository as soon as 

possible, as the current amount of standard is low (electronic communication, T. Cole to S. Levy, 

26-JAN-2015).

Food and Drug Administration (FDA) multiresidue method (MRM) testing data have been 

submitted for propoxycarbazone-sodium (as the free acid) and its metabolite Pr-2-OH. 

Propoxycarbazone-sodium and its metabolite Pr-2-OH were not adequately recovered from any 

of the MRMs (Memo, G. Kramer, 22-SEP-2003; DP#: 293677). Therefore, the MRM are not 

adequate for enforcement of tolerances for residues of propoxycarbazone-sodium and its Pr-2-

OH metabolite.

2.2.2 International Harmonization

With the exception of wheat grain, there are no Canadian, Mexican, or Codex maximum residue 

limits (MRLs) established for residues of propoxycarbazone-sodium. The Canadian MRL for

residues of propoxycarbazone-sodium and its metabolite in/on wheat, grain (0.02 ppm), is 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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equivalent to the U.S. tolerance expression and level. Therefore, harmonization is not an issue at 

this time. For a summary of U.S. tolerances, refer to Attachment 5.

2.2.3 Tolerance Recommendations

Tolerances for propoxycarbazone-sodium are currently established for the combined residues of 

propoxycarbazone-sodium and its Pr-2-OH metabolite [methyl 2-[[[(4,5-dihydro-3-(2-

hydroxypropoxy)-4-methyl-5-oxo-1H-1,2,4-triazol-1-yl)carbonyl]amino]sulfonyl]benzoate], 

expressed as parent, in/on wheat, forage at 17 ppm, wheat, grain at 0.02 ppm, wheat, hay at 0.15 

ppm and wheat, straw at 0.05 ppm [40 CFR §180.600(a)(1)]. In addition, tolerances are 

currently established for residues of propoxycarbazone per se in selected livestock commodities

at 0.03-0.3 ppm [40 CFR §180.600(a)(2)]. There are currently no Section 18 Emergency 

Exemptions, tolerances with regional registrations, or tolerances for indirect/inadvertent residues 

in rotational crops. 

The tolerance expression for propoxycarbazone-sodium has been reviewed and should be 

updated as follows, based on HED’s Interim Guidance on Tolerance Expressions (S. Knizner, 

27-MAY-2009).

40 CFR §180.600(a)(1) Tolerances are established for residues of the herbicide 

propoxycarbazone-sodium, including its metabolites and degradates, in or on the commodities in 

the table below. Compliance with the tolerance levels specified below is to be determined by 

measuring only the sum of propoxycarbazone-sodium (methyl 2-[[[(4,5-dihydro-4-methyl-5-oxo3-propoxy-1H-1,2,4-triazol-1-yl)carbonyl]amino]sulfonyl]benzoate sodium salt) and its 

metabolite methyl 2-[[[(4,5-dihydro-3-(2-hydroxypropoxy)-4-methyl-5-oxo-1H-1,2,4-triazol-1-

yl)carbonyl]amino]sulfonyl]benzoate, calculated as the stoichiometric equivalent of 

propoxycarbazone, in or on the commodity.

40 CFR §180.600(a)(2) Tolerances are established for residues of the herbicide 

propoxycarbazone-sodium, including its metabolites and degradates, in or on the commodities in 

the table below. Compliance with the tolerance levels specified below is to be determined by 

measuring only propoxycarbazone-sodium (methyl 2-[[[(4,5-dihydro-4-methyl-5-oxo-3-

propoxy-1H-1,2,4-triazol-1-yl)carbonyl]amino]sulfonyl]benzoate sodium salt), in or on the 

commodity.

The residue chemistry database supports the currently established tolerances as listed in 40 CFR 

§180.600. Table 2.2.3.1 is a summary of the established and HED-recommended tolerances for 

residues of propoxycarbazone-sodium. 

Table 2.2.3.1. Tolerance Summary for Propoxycarbazone-Sodium (40 CFR §180.600).

Commodity Established Tolerance (ppm) HED-Recommended Tolerance 

(ppm) Comments

40 CFR §180.600(a)(1)

Grass, forage 20

Grass, hay 25

Wheat, forage 17

Wheat, grain 0.02

Wheat, hay 0.15

Wheat, straw 0.05

40 CFR §180.600(a)(2)
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Table 2.2.3.1. Tolerance Summary for Propoxycarbazone-Sodium (40 CFR §180.600).

Commodity Established Tolerance (ppm) HED-Recommended Tolerance 

(ppm) Comments

Cattle, meat 0.05

Correct number of 

significant figures to be 

consistent with HED 

policy.

Cattle, meat byproducts 0.3 0.30

Goat, meat 0.05

Goat, meat byproducts 0.3 0.30

Horse, meat 0.05

Horse, meat byproducts 0.3 0.30

Milk 0.03

Sheep, meat 0.05

Sheep, meat byproducts 0.3 0.30

2.3 Label Recommendations

No revisions to the registered labels are required to support Registration Review.

3.0 Ingredient Profile

3.1 Chemical Identity and Physical/Chemical Properties

The chemical structure and nomenclature of propoxycarbazone-sodium and its metabolite Pr-2-

OH, and a detailed description of the physicochemical properties of propoxycarbazone-sodium 

are provided in Attachment 1. 

3.2 Use Pattern

Propoxycarbazone-sodium is registered as a DF formulation for control of certain grasses and 

broadleaf weeds in wheat and pastureland/rangeland. The maximum application rate for all uses 

is 0.05 lb a.i./A, and both broadcast and spot applications (in pastures/rangeland only) can be 

made using aerial, groundboom, and handheld equipment. Applications to wheat and triticale

can be made pre-plant, pre-emergence, or post-emergence, while applications to 

rangeland/pastureland is to only be made post-emergence. A summary of the registered uses are 

included in Attachment 3. 

3.3 Anticipated Exposure Pathways

Based on the registered application scenarios, dietary exposure is an anticipated exposure 

pathway as residues of propoxycarbazone-sodium may be found in/on crops, livestock, and 

drinking water. Although there are no registered residential uses of propoxycarbazone-sodium, 

there is a potential for spray drift that may result in exposures in residential and non-occupational 

settings. In an occupational setting, applicators may be exposed while handling the pesticide 

prior to application, as well as during application. There is also potential for post-application 

exposure for workers re-entering treated sites. This risk assessment considers all of the 

aforementioned exposure pathways based on the existing uses of propoxycarbazone-sodium.

3.4 Consideration of Environmental Justice 

Potential areas of environmental justice concerns, to the extent possible, were considered in this 

human health risk assessment, in accordance with U.S. Executive Order 12898, "Federal Actions 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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to Address Environmental Justice in Minority Populations and Low-Income Populations," 

(http://epa.gov/compliance/ej/resources/policy/exec_order_12898.pdf). As a part of every 

pesticide risk assessment, OPP considers a large variety of consumer subgroups according to 

well-established procedures. In line with OPP policy, HED estimates risks to population 

subgroups from pesticide exposures that are based on patterns of that subgroup’s food and water 

consumption, and activities in and around the home that involve pesticide use in a residential 

setting. Extensive data on food consumption patterns are compiled by the USDA’s 

NHANES/WWEIA and are used in pesticide risk assessments for all registered food uses of a 

pesticide. These data are analyzed and categorized by subgroups based on age and ethnic group. 

Additionally, OPP is able to assess dietary exposure to smaller, specialized subgroups and 

exposure assessments are performed when conditions or circumstances warrant. Whenever 

appropriate, non-dietary exposures based on home use of pesticide products and associated risks 

for adult applicators and for toddlers, youths, and adults entering or playing on treated areas 

post-application are evaluated. Further considerations are currently in development as OPP has 

committed resources and expertise to the development of specialized software and models that 

consider exposure to bystanders and farm workers as well as lifestyle and traditional dietary 

patterns among specific subgroups.

4.0 Hazard Identification/Toxicology

The main target organ of propoxycarbazone-sodium appears to be the gastrointestinal tract with 

irritation observed in the rat subchronic oral, rabbit developmental, and two-generation 

reproduction toxicity studies at relatively high doses (≥300 mg/kg/day). In the combined 

chronic/carcinogenicity toxicity study in rats, histopathological changes in the kidney and 

increased urinary pH were observed at approximately 500 mg/kg/day. In mice, effects from 

subchronic and chronic exposure were limited to body weight decrements at doses near or above 

the limit dose (1000 mg/kg/day). No effects were seen in dogs. 

There was no evidence of increased quantitative or qualitative susceptibility to offspring. In the 

rabbit developmental toxicity study, developmental toxicity (decreased fetal weights and 

increased pre- and post-implantation loss) was observed at the limit dose (1000 mg/kg/day), 

while maternal toxicity (gastrointestinal toxicity and body weight decrements) was seen at 500 

mg/kg/day. In the rat two-generation reproduction toxicity study, offspring toxicity (increased 

post-implantation loss and decreased litter size) was only noted at doses greater than the limit 

dose (>1200 mg/kg/day). Parental toxicity in this study was evidenced by microscopic lesions in 

the stomach at the mid-dose (~300 mg/kg/day). In the rat developmental toxicity study, no 

maternal or developmental effects were seen up to the limit dose (1000 mg/kg/day).

Propoxycarbazone-sodium was classified as having low acute toxicity via the oral, dermal, and 

inhalation routes (Toxicity Category IV). It is not an eye irritant, dermal irritant, or dermal 

sensitizer. No toxicity was observed at the limit dose in a 28-day dermal toxicity study in rats.

Propoxycarbazone-sodium is classified as “not likely to be carcinogenic to humans” based on 

lack of evidence of carcinogenicity in mice and rats and negative findings in mutagenicity 

assays.

The toxicology database for propoxycarbazone-sodium is complete for Registration Review 

except for the subchronic inhalation study that is required in accordance with the current 40 CFR 

Part 158 Toxicology Data Requirements. However, the HASPOC concluded, based on a weightof-evidence approach, that this study is not required at this time (U. Habiba; 18-NOV-2014; 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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TXR#0057073). The endpoints, PODs, and SFs for propoxycarbazone-sodium from the mostrecent human health risk assessment (Memo, S. Levy et al., 10-DEC-2008; D348510) are 

considered protective of all effects seen in the database; however, the following updates were 

made to reflect current HED policy: one endpoint was selected to assess both short- and 

intermediate-term inhalation exposures, and endpoints for long-term dermal and inhalation 

exposures are not needed because long-term exposures are not expected based on the use pattern 

for propoxycarbazone-sodium. For all exposure scenarios, a 100-fold UF (10X for interspecies 

extrapolation, 10X for intraspecies variation, and 1X for FQPA SF when applicable) was 

applied. 

Table 4.0.1. Summary of Toxicological Doses and Endpoints for Propoxycarbazone-Sodium for Use in Dietary and 

Non-Occupational Human-Health Risk Assessments.

Exposure/ 

Scenario POD UFs/FQPA SF

RfD, PAD, LOC for 

Risk Assessment Study and Toxicological Effects

Acute Dietary

(All populations) A dose and endpoint of concern attributable to a single dose was not observed.

Chronic Dietary 

(All Populations)

NOAEL = 

74.8 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

Chronic Rfd =

0.748 mg/kg/day

cPAD = 

0.748 mg/kg/day

Two-Generation Reproduction 

Study

LOAEL = 297.1 mg/kg/day based on 

microscopic lesions of the stomach in 

parental male rats.

Incidental Oral 

Short-Term 

(1-30 days) and 

Intermediate-Term 

(1-6 months)

NOAEL = 

74.8 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

Residential LOC for 

MOE = 100

Two-Generation Reproduction 

Study

LOAEL = 297.1 mg/kg/day based on 

microscopic lesions of the stomach in 

parental male rats.

Dermal

Short-Term 

(1-30 days) and 

Intermediate-Term 

(1-6 months)

No dermal assessment required. No adverse effects were seen up to the limit dose in the route-specific 

dermal toxicity study and there was no evidence of quantitative susceptibility. Additionally, the 

gastrointestinal effects seen in oral studies would not be expected to occur following a dermal exposure.

Cancer (oral, 

dermal, inhalation) Classification: “not likely to be carcinogenic to humans.”

Point of departure (POD) = A data point or an estimated point that is derived from observed dose-response data and used to mark 

the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures. NOAEL = 

no-observed adverse-effect level. LOAEL = lowest-observed adverse-effect level. UF = uncertainty factor. UFA = extrapolation 

from animal to human (interspecies). UFH = potential variation in sensitivity among members of the human population 

(intraspecies). FQPA SF = FQPA Safety Factor. PAD = population-adjusted dose (a = acute, c = chronic). RfD = reference 

dose. MOE = margin of exposure. LOC = level of concern. 

Table 4.0.2. Summary of Toxicological Doses and Endpoints for Propoxycarbazone-Sodium for Use in Occupational 

Human-Health Risk Assessments.

Exposure/ 

Scenario POD UFs LOC for Risk Assessment Study and Toxicological Effects

Dermal

Short-Term 

(1-30 days) and 

Intermediate-Term 

(1-6 months)

No dermal assessment required. No adverse effects were seen up to the limit dose in the route-specific 

dermal toxicity study and there was no evidence of quantitative susceptibility. Additionally, the 

gastrointestinal effects seen in oral studies would not be expected to occur following a dermal exposure.

Inhalation ShortTerm 

(1-30 days) and 

Intermediate-term 

(1-6 months)

NOAEL = 

74.8 

mg/kg/day

UFA = 10X

UFH = 10X

FQPA SF = 1X

Occupational LOC for 

MOE = 100

Two-Generation Reproduction 

Study

LOAEL = 297.1 mg/kg/day based on 

microscopic lesions of the stomach in 

parental male rats.
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Table 4.0.2. Summary of Toxicological Doses and Endpoints for Propoxycarbazone-Sodium for Use in Occupational 

Human-Health Risk Assessments.

Exposure/ 

Scenario POD UFs LOC for Risk Assessment Study and Toxicological Effects

Cancer (oral, 

dermal, inhalation) Classification: “not likely to be carcinogenic to humans.”

Point of departure (POD) = A data point or an estimated point that is derived from observed dose-response data and used to mark 

the beginning of extrapolation to determine risk associated with lower environmentally relevant human exposures. NOAEL = 

no-observed adverse-effect level. LOAEL = lowest-observed adverse-effect level. UF = uncertainty factor. UFA = extrapolation 

from animal to human (interspecies). UFH = potential variation in sensitivity among members of the human population 

(intraspecies). MOE = margin of exposure. LOC = level of concern.

4.1 Endocrine Disruptor Screening Program

As required by the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and the Federal 

Food, Drug, and Cosmetic Act (FFDCA), EPA reviews numerous studies to assess potential 

adverse outcomes from exposure to chemicals. Collectively, these studies include acute, 

subchronic, and chronic toxicity, including assessments of carcinogenicity, neurotoxicity, 

developmental, reproductive, and general or systemic toxicity. These studies include endpoints 

which may be susceptible to endocrine influence, including effects on endocrine target organ 

histopathology, organ weights, estrus cyclicity, sexual maturation, fertility, pregnancy rates, 

reproductive loss, and sex ratios in offspring. For ecological hazard assessments, EPA evaluates 

acute tests and chronic studies that assess growth, developmental and reproductive effects in

different taxonomic groups. As part of its reregistration decision for propoxycarbazone-sodium, 

EPA reviewed these data and selected the most sensitive endpoints for relevant risk assessment 

scenarios from the existing hazard database. However, as required by FFDCA section 408(p), 

propoxycarbazone-sodium is subject to the endocrine screening part of the Endocrine Disruptor 

Screening Program (EDSP).

EPA has developed the EDSP to determine whether certain substances (including pesticide 

active and other ingredients) may have an effect in humans or wildlife similar to an effect 

produced by a “naturally occurring estrogen, or other such endocrine effects as the Administrator 

may designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine-related effects caused by the substance, and 

establish a dose-response relationship between the dose and the E, A, or T effect.

Under FFDCA section 408(p), the Agency must screen all pesticide chemicals. Between 

October 2009 and February 2010, EPA issued test orders/data call-ins for the first group of 67 

chemicals, which contains 58 pesticide active ingredients (a.i.’s) and 9 inert ingredients. A 

second list of chemicals identified for EDSP screening was published on June 14, 20131and 

includes some pesticides scheduled for Registration Review and chemicals found in water.

Neither of these lists should be construed as a list of known or likely endocrine disruptors.

 

1

See http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0477-0074 for the final second list of

chemicals
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 12 of 29

For further information on the status of the EDSP, the policies and procedures, the lists of 

chemicals, future lists, the test guidelines and the Tier 1 screening battery, please visit our 

website.2

5.0 Dietary Exposure and Risk Assessment

5.1 Residue Chemistry

Permanent tolerances are established for the combined residues of propoxycarbazone-sodium 

and its Pr-2-OH metabolite, expressed as parent, in/on a variety of crops, with tolerances ranging 

from 0.02 ppm to 25 ppm (40 CFR §180.600 (a)). In addition, tolerances are currently 

established for residues of propoxycarbazone per se in selected livestock commodities at 0.03-

0.3 ppm [40 CFR §180.600(a)(2)]. There are currently no Section 18 Emergency Exemptions, 

tolerances with regional registrations, or tolerances for indirect/inadvertent residues in rotational 

crops.

Adequate methods are available for enforcing the current plant and livestock tolerances. In all 

available magnitude of the residue and processing studies, samples were analyzed using either 

the current enforcement methods or a slightly modified version of current enforcement methods.

The analytical method has been deemed acceptable; however HED concluded the method 

instructions should be modified to clearly state that propoxycarbazone-sodium as the free acid is 

the compound to be used for preparation of standard and fortification solutions. The method 

description needs to specify any chemical information for the standards to clarify which 

compound is to be used (Memo, G. Kramer, 22-APR-2004; D284670).

The nature of the residue in wheat/grass and livestock is adequately understood based on 

available metabolism studies. For risk assessment purposes, only parent will be considered for 

plant and livestock commodities. Adequate field trial and processing data are available to 

support the use of propoxycarbazone-sodium on the registered crops. An adequate number of 

trials were conducted in the appropriate geographical regions using the appropriate formulation 

applied at the maximum use rate. Registration requirements for magnitude of the residue in 

meat, milk, poultry, and eggs are fulfilled. 

A previous condition of registration was the need for additional grass field trials reflecting a 

preharvest interval (PHI) of 7-days for hay (Memos, S. Levy, 25-SEP-2013; D412002 and 

D412251). However, upon further evaluation of the previously-submitted field trial data, HED is 

no longer requiring these additional trials. Based on the complete 0-day forage data set, a hay

decline study, and the theoretical drying factor and moisture content of forage to hay (~3 fold), 

residues can be extrapolated for hay at 7 days (calculated to be a maximum of ~12 ppm). The 

currently-established 25-ppm tolerance for grass, hay is adequate to cover any residues detected 

for hay at the PHI of 7 days. 

The residue chemistry database is adequate to support current Registration Review data 

requirements. Adequate metabolism (crops, livestock, and rotational crops), storage stability, 

magnitude of the residue, and processing data are available to support the registered uses. 

Adequate methods are available for enforcement of the currently established tolerances. 

 

2 http://www.epa.gov/endo/
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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5.2 Drinking Water

The residues of concern in drinking water are adequately understood based on available 

environmental fate studies. The HED Metabolism Assessment Review Committee (MARC)

concluded that the residue of concern for the drinking water risk assessment should include the 

parent compound plus propoxycarbazone-carboxylic acid (MKH 8394) (Report of the 

Metabolism Assessment Review Committee – MARC, G. Kramer, 19-APR-2004; D299170).

Updated groundwater EDWCs for propoxycarbazone-sodium were provided by EFED (Memo, J. 

Lin, 04-DEC-2014; D423552). The EDWCs were derived using the Pesticide Root Zone ModelGround Water (PRZM-GW) model and assuming maximum application rates. The surface water 

concentrations are on the same order of magnitude as the ground water concentrations. For acute 

exposure, the surface water concentration (4.16 μg/L) is higher than that for ground water, 

whereas for chronic exposure, the ground water value (2.8 μg/L) is higher. These results are 

similar to previous drinking water assessment results, with an increase in ground water estimates 

relative to previous estimates (D348511): surface water acute, 4.59 μg/L; surface water chronic, 

1.79 μg/L; ground water acute and chronic, 0.36 μg/L.

5.3 Dietary (Food + Drinking Water) Risk Assessment

In support of Registration Review, an updated chronic dietary (food + drinking water) exposure 

and risk assessment was conducted using DEEM-FCID (ver. 3.16) which incorporates 

consumption data from the USDA NHANES/WWEIA; 2003-2008. The chronic analyses 

assumed tolerance-level residues, 100% CT, DEEM (ver. 7.81) default processing factors, and 

modeled drinking water estimates. The groundwater EDWC of 0.0028 ppm was incorporated 

directly into the chronic dietary analyses as “water, direct, all sources” and “water, indirect, all 

sources.” The groundwater EDWC used the modeled application rate of 0.0525 lb a.i./acre to 

represent the maximum use pattern of the proposed end-use labels and current registered labels. 

The chronic dietary (food + drinking water) exposure estimates are below HED’s LOC (<100%

cPAD) for the general U.S. population and all population subgroups (<1% of the cPAD) (see 

Table 5.3.1). The residue file for the chronic assessment as well as the results of the chronic 

assessment are provided in Attachment 4. An acute dietary (food + drinking water) exposure and 

risk assessment was not conducted for propoxycarbazone-sodium because an endpoint of 

concern attributable to a single oral dose was not selected for any population subgroup (including 

infants and children). Propoxycarbazone-sodium was classified as “not likely to be carcinogenic 

to humans”; therefore, a cancer dietary assessment was not performed. 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Table 5.3.1. Summary of Chronic Dietary (Food + Drinking Water) Exposure and Risk for 

Propoxycarbazone-sodium.

1

Population Subgroup cPAD (mg/kg/day) Exposure (mg/kg/day) %cPAD

General U.S. Population

0.7

0.000320 <1

All Infants (<1 year old) 0.000530 <1

Children 1-2 years old 0.001513 <1

Children 3-5 years old 0.000919 <1

Children 6-12 years old 0.000539 <1

Youth 13-19 years old 0.000274 <1

Adults 20-49 years old 0.000220 <1

Adults 50-99 years old 0.000203 <1

Females 13-49 years old 0.000219 <1

1 The population subgroup with the highest exposure is in bold. 

6.0 Residential (Non-Occupational) Exposure and Risk Assessment

There are no proposed or registered products containing propoxycarbazone-sodium that would 

result in residential exposure. Therefore, a residential exposure assessment was not performed.

6.1 Spray Drift

Off-target movement of pesticides can occur via many types of pathways and it is governed by a 

variety of factors. Sprays that are released and do not deposit in the application area end up offtarget and can lead to exposures to those it may directly contact. They can also deposit on 

surfaces where contact with residues can eventually lead to exposures (e.g., children playing on 

lawns where residues have deposited next to treated fields). The potential risk estimates from 

these residues can be calculated using drift modeling coupled with methods employed for 

residential risk assessments for turf products.

The approach to be used for quantitatively incorporating spray drift into risk assessment include 

assessing exposures for children (1 to 2 years old) and adults who have contact with turf where 

residues are assumed to have deposited via spray drift thus resulting in an exposure scenario. 

Aside from the predicted residues available for transfer, the routes of exposure and assessment 

methodology is analogous to how exposures to turf products are considered in risk assessment. 

In order to evaluate the drift potential and associated risks, an approach based on drift modeling 

coupled with techniques used to evaluate residential uses of pesticides was utilized. Essentially, 

a residential turf assessment based on exposure to deposited residues has been completed to 

address drift from the agricultural applications of propoxycarbazone-sodium. In the spray-drift

scenario, the deposited residue value was determined based on the amount of spray drift that may 

occur at varying distances from the edge of the treated field using the AgDrift® (v2.1.1) model. 

Exposures were considered for 50-feet wide lawns where the nearest side of the property was 

directly adjoining the treated field (at field edge) and at varied distances up to 300 feet 

downwind of a treated field. Once the deposited residue values were determined, the remainder 

of the spray-drift assessment was based on the algorithms and input values specified in the 

recently revised (2012) Standard Operating Procedures For Residential Risk Assessment 

(SOPs). 

 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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A screening approach was developed for situations where specific label guidance for application 

parameters is not available.3 AgDrift® is appropriate for use only when applications are made by 

aircraft, airblast sprayers, and groundboom sprayers. When AgDrift® was developed, a series of 

screening values (i.e., the Tier 1 option) were incorporated into the model and represent each 

equipment type and use under varied conditions. The screening options specifically 

recommended in this methodology were selected because they are plausible and represent a 

reasonable upper-bound level of drift for common application methods in agriculture. In all 

cases, each scenario is to be evaluated unless it is not plausible based on the anticipated use 

pattern (e.g., herbicides are not typically applied to tree canopies) or specific label prohibitions 

(e.g., aerial applications are not allowed). Section 6.1.1 provides the screening-level drift-related 

risk estimates. These drift estimates represent plausible options based on the available pesticide 

labels.

6.1.1 Combined Risk Estimates From Lawn Deposition Adjacent to Applications

The spray-drift risk estimates are based on an estimated deposited residue concentration as a 

result of the screening level agricultural application scenarios. Propoxycarbazone-sodium is an 

herbicide registered for use on wheat and pastures/rangeland and can be applied via groundboom 

and aerial equipment. The recommended drift scenario screening level options are listed below: 

 Groundboom applications are based on the AgDrift® option for high boom height and 

using very fine to fine spray type using the 90th percentile results. 

 Aerial applications are based on the use of AgDrift® Tier 1 aerial option for a fine to 

medium spray type and a series of other parameters, which will be described in more 

detail below (e.g., wind vector assumed to be 10 mph in a downwind direction for entire 

application/drift event).4

There are no short- or intermediate-term dermal PODs. Only incidental oral risk estimates were 

evaluated. The total applicable LOC is 100, so MOEs <100 would be of concern. Children (1 to 

<2 years old) incidental oral risk estimates from exposure to propoxycarbazone-sodium related to 

spray drift result in no risks of concern at the field edge for either groundboom or for aerial 

applications (Table 6.1.1.1).

Table 6.1.1.1. Children (1 to <2 years old) Incidental Oral Risk Estimates (MOEs) Related to Spray-Drift 

Exposure for Propoxycarbazone-sodium.

Crop Application 

Method

Spray Type/Nozzle 

Configuration

Application 

Rate

(lb a.i./A)

Estimated 

TTRt

(ug/cm2)

At Edge

HtM MOE

Wheat

Aerial Fine to Medium

0.04 0.0044

640,000

Groundboom High Boom Very fine to Fine 880,000

Pastureland / 

Rangeland

Aerial Fine to Medium

0.05 0.0056

510,000

Groundboom High Boom Very fine to Fine 700,000

 

3http://www.agdrift.com/

4 AgDrift® allows for consideration of even finer spray patterns characterized as very fine to fine. However, this 

spray pattern was not selected as the common screening basis since it is used less commonly for most agriculture.
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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6.2 Residential Bystander Post-Application Inhalation Exposure

Volatilization of pesticides may be a source of post-application inhalation exposure to 

individuals nearby pesticide applications. The Agency sought expert advice and input on issues 

related to volatilization of pesticides from its FIFRA Scientific Advisory Panel (SAP) in 

December 2009, and received the SAP’s final report on March 2, 20105. The Agency has 

evaluated the SAP report and has developed a Volatilization Screening Tool and a subsequent 

Volatilization Screening Analysis6. During Registration Review, the Agency will utilize this 

analysis to determine if data (i.e., flux studies, route-specific inhalation toxicological studies) or 

further analysis is required for propoxycarbazone-sodium.

7.0 Aggregate Exposure and Risk Assessment

The most recent aggregate-risk assessment for propoxycarbazone-sodium was performed in 

conjunction with the 2008 HED human health risk assessment (Memo, S. Levy et al., 10-DEC2008; D348510). Since there are no residential uses, the chronic dietary (food + drinking water)

exposure estimates represent chronic aggregate exposure. Updated chronic dietary (food +

drinking water) exposure and risk assessments were conducted to include the updated EDWC

and 2003-2008 NHANES/WWEIA consumption data (discussed in Section 5.3). The chronic 

aggregate (food + drinking water) exposure and risk estimates did not exceed HED's LOC. 

An acute aggregate risk assessment was not performed because an endpoint of concern 

attributable to a single oral dose was not selected for any population subgroup (including infants 

and children). Short- and intermediate-term aggregate risk assessments were not performed 

because there are no registered residential uses. A cancer aggregate risk assessment was not 

performed because propoxycarbazone-sodium is not classified by HED as “not likely to be 

carcinogenic to humans.” 

8.0 Cumulative Exposure/Risk Characterization

Unlike other pesticides for which EPA has followed a cumulative risk approach based on a 

common mechanism of toxicity, EPA has not made a common mechanism of toxicity finding as 

to propoxycarbazone-sodium and any other substances and propoxycarbazone-sodium does not 

appear to produce a toxic metabolite produced by other substances. For the purposes of this 

action, therefore, EPA has assumed that propoxycarbazone-sodium does not have a common 

mechanism of toxicity with other substances. For information regarding EPA’s efforts to 

determine which chemicals have a common mechanism of toxicity and to evaluate the 

cumulative effects of such chemicals, see the policy statements released by EPA’s Office of 

Pesticide Programs concerning common mechanism determinations and procedures for 

cumulating effects from substances found to have a common mechanism on EPA’s website at 

http://www.epa.gov/pesticides/cumulative/.

 

5 http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html

6 http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2014-0219
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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9.0 Occupational Exposure 

Occupational handler and post-application exposures are expected based on the registered 

agricultural uses of propoxycarbazone-sodium. Table A.3.1 in Attachment 3 provides a 

summary of the registered use pattern. Based on the registered use pattern, there is a potential 

for exposure to propoxycarbazone-sodium in occupational settings from handling 

propoxycarbazone-sodium products during the application process (i.e., mixer/loaders, 

applicators, and mixer/loader/applicators). In addition, there is a potential for post-application 

worker exposure from entering into areas previously treated with propoxycarbazone-sodium.

9.1 Occupational Handlers

Occupational handlers are anticipated to have short- and intermediate-term dermal and inhalation 

exposures. However, since no short- or intermediate-term dermal PODs were selected, only 

inhalation exposures are assessed. In support of Registration Review, an updated occupational 

exposure assessment for propoxycarbazone-sodium was conducted for mixers/loaders, 

applicators, and flaggers for aerial and groundboom applications of a DF formulation, as well as 

mixer/loader/applicators performing spot treatments with handheld equipment. The assessment 

was based on the maximum registered application rate of 0.05 lb a.i./A (0.002 lb a.i./gallon), and 

maximum area treated per day or gallons handled. Handler exposure and risk were calculated at 

baseline (long pants, a long-sleeved shirt, no chemical-resistant gloves, and no respirator) and 

with personal-protective equipment (PPE) when necessary [e.g., engineering controls (EC)]. 

Inhalation risk estimates were not of concern (i.e., MOEs ≥ 100) with baseline protection and/or 

engineering controls (representative of aerial applicators in enclosed cabs) (see Table 9.1.1). 

PPE on registered labels recommends mixers/loaders and other handlers to wear long sleeved 

shirts, long pants, chemical-resistant gloves, shoes plus socks, and protective eyewear. 

Table 9.1.1. Summary of Occupational Handler Inhalation Risks for Propoxycarbazone-sodium.

Activity Application 

Equipment Crop/Target

Inhalation 

Unit Exposure 

(μg/lb ai)1

App 

Rate2

Acres

Treated 

or 

Gallons 

Handled3

Dose4 ST and IT 

Inhalation MOE5

Mixer/Loader

Groundboom 

application of DF 

formulation

Wheat, Triticale, 

Pastureland / 

Rangeland

8.96 (baseline) 0.05 lb 

a.i./A

200 A 0.0011 67,000 (baseline)

Aerial application of 

DF formulation 1,200 A 0.0067 11,000 (baseline)

Applicator

Applicator, Open Cab 

Groundboom Wheat, 

Pastureland / 

Rangeland

0.34 (baseline) 0.05 lb 

a.i./A

200 A 0.000043 1,800,000 

(baseline)

Applicator, Aerial 0.0049 (EC) 1,200 A

0.000003

7

20,000,000 (EC)

Flagger

Aerial

Wheat, 

Pastureland / 

Rangeland

0.35 (baseline) 0.05 lb 

a.i./A 350 A 0.000077 980,000 (baseline)

Mixers/Loaders/Applicators

Backpack

Pastureland / 

Rangeland

140 0.002 lb 

a.i./

gallon

40 gallons

0.00014 540,000 (baseline)

Manually-pressurized 

Handwand 30 0.00003 2,500,000 (baseline)

Mechanically- 3.9 1000 0.000098 770,000 (baseline)
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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pressurized Handgun gallons

1 Based on the “Occupational Pesticide Handler Unit Exposure Surrogate Reference Table” (March 2013); Level of mitigation: Baseline, EC = 

Eng. Controls.

2 Based on registered labels.

3 Exposure Science Advisory Council Policy #9.1.

4

Inhalation Dose = Inhalation Unit Exposure (μg/lb ai) × Conversion Factor (0.001 mg/μg) × Application Rate (lb a.i./acre or lb a.i./gallon) × 

Area Treated or Amount Handled (A or gallons/day) × absorption factor (100%) ÷ BW (80 kg).

5

Inhalation MOE = Inhalation NOAEL (75 mg/kg/day) ÷ Inhalation Dose (mg/kg/day). 

9.2 Occupational Post-Application

Dermal: Typically, it is possible for agricultural workers to have post-application exposure to 

pesticide residues during the course of typical agricultural activities. However the Agency did 

not identify a dermal toxicological endpoint; therefore, a quantitative assessment for dermal 

post-application exposure was not conducted. 

The restricted-entry interval (REI) specified on the registered labels is based on the acute toxicity 

of the a.i. Propoxycarbazone-sodium is classified as Toxicity Category IV via the dermal route 

and for skin irritation potential. It is not a skin sensitizer. Under 40 CFR 156.208 (c) (2) (iii), 

ai’s classified as Acute III or IV for acute dermal, eye irritation and primary skin irritation are 

assigned a 12-hour REI. Therefore, the [156 subpart K] Worker Protection Statement (WPS)

interim REI of 12 hours is adequate to protect agricultural workers from post-application 

exposures to propoxycarbazone-sodium. It should be noted that several of the registered 

products contain another a.i. that should be considered when selecting the REI for the product.

Inhalation: There are multiple potential sources of post-application inhalation exposure to 

individuals performing post-application activities in previously treated fields. These potential 

sources include volatilization of pesticides and resuspension of dusts and/or particulates that 

contain pesticides. The Agency sought expert advice and input on issues related to volatilization 

of pesticides from its FIFRA SAP in December 2009, and received the SAP’s final report on 

March 2, 2010 (http://www.epa.gov/scipoly/SAP/meetings/2009/120109meeting.html). In terms 

of volatilization, the Agency has evaluated the SAP report and has developed a Volatilization 

Screening Tool and a subsequent Volatilization Screening Analysis 

(http://www.regulations.gov/#!docketDetail;D=EPA-HQ-OPP-2014-0219). During Registration 

Review, the Agency will utilize this analysis to determine if data (i.e., flux studies, route-specific 

inhalation toxicological studies) or further analysis is required for specific chemicals.

In addition, the Agency is continuing to evaluate the available post-application inhalation 

exposure data generated by the ARTF. Given these two efforts, the Agency will continue to 

identify the need for and, subsequently, the way to incorporate occupational post-application 

inhalation exposure into the Agency's risk assessments.

Although a quantitative occupational post-application inhalation exposure assessment was not 

performed, an inhalation exposure assessment was performed for occupational/commercial 

handlers. Handler exposure resulting from application of pesticides outdoors is likely to result in 

higher exposure than post-application exposure. Therefore, it is expected that these handler 

inhalation exposure estimates would be protective of most occupational post-application 

inhalation exposure scenarios. Based on this, HED concludes that additional data pertaining to 

assessment of post-application inhalation exposure are unnecessary. 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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10.0 Public Health and Pesticide Epidemiology Data

The Agency has reviewed the available incident data for propoxycarbazone-sodium (Memo, E. 

Evans and S. Recore, 21-JAN-2015; D425154). It is noted that there was one incident reported 

involving propoxycarbazone-sodium in both the Aggregate Incident Data System (IDS) and the 

Sentinel Event Notification System for Occupational Risk (SENSOR)-Pesticides databases. 

Based on the low frequency and low severity of cases involving propoxycarbazone-sodium, there 

does not appear to be a concern at this time that would warrant further investigation. The 

Agency will continue to monitor the incident information and if a concern is triggered, additional 

analysis will be included in the risk assessment.

11.0 References

HED Memoranda Relevant to Registration Review.

Author Barcode Date Title

Mark I. Dow D301651 22-Apr-2014 PROPOXYCARBAZONE-SODIUM - Exposure/Risk 

Assessment for the Use of Propoxycarbazone-sodium on 

Wheat.

Mark I. Dow D349694 17-Mar-2008 PROPOXYCARBAZONE-SODIUM - Occupational 

Exposure/Risk Assessment for the Proposed Use of 

Propoxycarbazone-sodium on Pastures and Rangeland.

E. Evans and S. Recore D425154 21-JAN-2015 Propoxycarbazone-sodium: Tier I Review of Human Incidents.

G. Kramer D293677 22-SEP-2003 PP#1E06302. Multiresidue Method (MRM) Testing of 

Propoxycarbazone-sodium.

S. Levy D412002 25-SEP-2013 Propoxycarbazone-sodium; Response to the Health Effects 

Division (HED) Review of 05-AUG-2009.

S. Levy et al. D348510 10-DEC-2008 Propoxycarbazone-sodium. Human Health Risk Assessment 

for Proposed Section 3 New Use on Pasture and Rangeland 

Grasses.

J. Lin D423552 04-DEC-2014 Propoxycarbazone-sodium: Drinking Water Exposure 

Assessment for Registration Review.

G. Kramer D299170 19-APR-2004 MARC Report.

U. Habiba TXR# 0057073 18-NOV-2014 Propoxycarbazone-sodium: Summary of the Hazard and 

Science Policy Council (HASPOC) Meeting on October 9, 

2014. Recommendations on the Requirement of a Subchronic 

Inhalation Study.
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 20 of 29

Attachment 1: Chemical Identity Tables.

Table A.1.1. Nomenclature of Propoxycarbazone-sodium and its Regulated Metabolite.

Chemical Structure

O

CH3

S

O

O

O

N

N

O

N

N

CH3

O

CH3

O

Na

+

Common name Propoxycarbazone-sodium

Company experimental names AE 1169718, MKH 6561

IUPAC name Sodium {[2-(methoxycarbonyl)phenyl]sulfonyl}[(4,5-dihydro-4-methyl-5-oxo-3-

propoxy-1H-1,2,4-triazol-1-yl)carbonyl]azanide

CAS name Methyl 2-[[[(4,5-dihydro-4-methyl-5-oxo-3-propoxy-1H-1,2,4-triazol-1-yl)carbonyl] 

amino]sulfonyl]benzoate, sodium salt

CAS # 181274-15-7 (sodium salt); 145026-81-9 (acid)

Chemical Structure

O

CH3

S

O

O

O

N N

O

N

N

CH3

O

CH3

O

OH

Common Name 2-OH Propoxycarbazone

Company Experimental Name AE 1364270, Pr-2-OH-MHK 6561
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Table A.1.2. Physicochemical Properties of Propoxycarbazone-sodium (sodium salt).

Parameter Value Reference

Boiling range 230-240oC MRID#: 46580801

pH (at 24oC) 6.6

Density (g/mL at 20oC) 1.42

Water solubility (mg/L at 20°C) 42

Solvent solubility (g/L at 25°C) DMSO 190

Acetonitrile 0.90

Acetone 0.50

PEG 5.2

Methylene Chloride 1.5

Heptane <1

Zylene <1

Isopropanol <1

Octanol <1

Ethyl Acetate <1

Vapor pressure (Torr at 20°C) 7.50 x 10-11

Dissociation constant (pKa) 2.1

Octanol/water partition coefficient (KOW) at 20oC 0.028

UV/visible absorption spectrum (max, nm) Primary: 200

Secondary: 232

Tertiary: 275
Propoxycarbazone-sodium Human Health Risk Assessment D423232

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Attachment 2: Propoxycarbazone-Sodium Acute, Subchronic, and Chronic Toxicity 

Profile.

Study requirements (40 CFR 158.340) for propoxycarbazone-sodium are presented below. Use 

of the new guideline numbers does not imply that the new (1998) guideline protocols were used.

Table A.2.1. Toxicology Study Requirements.

Study Technical

Required Satisfied

870.1100 Acute Oral Toxicity ......................................................

870.1200 Acute Dermal Toxicity .................................................

870.1300 Acute Inhalation Toxicity .............................................

870.2400 Acute Eye Irritation ......................................................

870.2500 Acute Dermal Irritation.................................................

870.2600 Skin Sensitization .........................................................

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

yes

870.3100 90-Day Oral Toxicity (rodent)......................................

870.3150 90-Day Oral Toxicity (nonrodent)................................

870.3200 21/28-Day Dermal Toxicity..........................................

870.3250 90-Day Dermal Toxicity...............................................

870.3465 90-Day Inhalation Toxicity...........................................

yes

yes

yes

no

no1

yes

yes

yes

--

--

870.3700a Prenatal Developmental Toxicity (rodent)....................

870.3700b Prenatal Developmental Toxicity (nonrodent)..............

870.3800 Reproduction and Fertility Effects................................

yes

yes

yes

yes

yes

yes

870.4100a Chronic Toxicity (rodent) .............................................

870.4100b Chronic Toxicity (nonrodent) .......................................

870.4200a Carcinogenicity (rat) .....................................................

870.4200b Carcinogenicity (mouse)...............................................

870.4300 Combined Chronic Toxicity/Carcinogenicity...............

yes

yes

yes

yes

yes

yes2

yes

yes2

yes

yes

870.5100 Mutagenicity—Bacterial Reverse Mutation Test .........

870.5300 Mutagenicity—Mammalian Cell Gene Mutation Test .

870.5xxx Mutagenicity— Structural Chromosomal Aberrations.

870.5xxx Mutagenicity—Other Genotoxic Effects......................

yes

yes

yes

yes

yes

yes

yes

yes

870.6200a Acute Neurotoxicity Screening Battery (rat) ................

870.6200b 90-Day Neurotoxicity Screening Battery (rat)..............

870.6300 Developmental Neurotoxicity.......................................

yes

yes

no

yes

yes

--

870.7485 Metabolism and Pharmacokinetics ...............................

870.7600 Dermal Penetration .......................................................

870.7800 Immunotoxicity ............................................................

yes

no

yes

yes

--

yes

1 HED HASPOC concluded that the subchronic inhalation is not required at this time (U. Habiba; 18-NOV-2014; 

TXR#0057073).

2 The combined chronic toxicity/carcinogenicity study satisfies the requirement of the study. 

Table A.2.2. Acute Toxicity Profile – Propoxycarbazone-sodium.

Guideline No. Study Type MRID(s) Results Toxicity 

Category

870.1100 Acute Oral (rat) 45012509 LD50 > 5000 mg/kg IV

870.1200 Acute Dermal 45012507/45012508 LD50 > 5000 mg/kg IV

870.1300 Acute Inhalation 45012505 LC50 > 5.03 mg/L IV

870.2400 Primary Eye Irritation 45012504 Minimally irritating IV

870.2500 Primary Skin Irritation 45012504 Slightly irritating IV

870.2600 Dermal Sensitization 45012510 Not a dermal sensitizer N/A
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 23 of 29

Note: It is recognized that some studies in the propoxycarbazone-sodium database have 

conservative NOAEL/LOAEL values that are based on effects that are not considered adverse 

according to current HED policy (e.g., body-weight gain). These updates, however, would result 

only in higher NOAEL/LOAEL values in studies that were not used for endpoint selection; 

therefore, the updates would not affect current PODs. Consequently, given the current risk 

picture for propoxycarbazone-sodium, the Agency did not find it necessary to update these 

studies at this time; however, if the risk picture changes, then these studies may need to be 

updated in the future. 

Table A.2.3. Subchronic, Chronic, and Other Toxicity Profile – Propoxycarbazone-sodium.

Guideline No./ 

Study Type

MRID No. (year)/ Classification 

/Doses Results

870.3100

90-Day oral toxicity 

(rat)

45012610 (1998)

Acceptable/guideline

0, 250, 1000, 4000 or 20,000 ppm

M: 0, 21.6, 81.6, 350.6, or 1769.9 

mg/kg/day

F: 0, 17.4, 73.0, 286.4, or 1507.5 

mg/kg/day

NOAEL = 286.4/350.6 mg/kg/day (M/F).

LOAEL = 1507.5/1769.9 mg/kg/day (M/F) based 

on gastric irritation.

870.3100

90-Day oral toxicity 

(mouse)

45012521 (1997)

Acceptable/guideline

0, 625, 2500 or 10,000 ppm

M: 0, 205, 860, or 3926 mg/kg/day

F: 0, 307, 1159, or 5109 mg/kg/day

NOAEL = 205/1159 mg/kg/day (M/F).

LOAEL = 860/5109 mg/kg/day (M/F) based on 

decreased body weight, body-weight gain, and 

food efficiency.

870.3150

64-Day oral toxicity 

(dog)

(range-finding)

45012511 (1997)

Acceptable/guideline

0, 1000, 5000, 10,000 or 40,000 

ppm 

M: 0, 28, 140, 332, and 1407 

mg/kg bw/day

F: 0, 32, 134, 286, or 1181 mg/kg/

day

NOAEL = 1407/1181 mg/kg/day (M/F). 

LOAEL = not determined.

870.3200

21/28-Day dermal 

toxicity

45012530 (1997)

Acceptable/non-guideline

0 or 1000 mg/kg/day

NOAEL = 1000 mg/kg/day.

LOAEL = not determined.

870.3700a

Prenatal 

developmental 

rodent (rat)

45012515 (1997)

Acceptable/guideline

0, 100, 300, or 1000 mg/kg/day

Maternal NOAEL  1000 mg/kg/day.

LOAEL = not determined.

Developmental NOAEL  1000 mg/kg/day.

LOAEL = not determined.

870.3700b

Prenatal 

developmental in 

nonrodents (rabbit)

45012608 (1998)

Acceptable/guideline

0, 20, 100, 500, or 1000 mg/kg/day

Maternal NOAEL = 100 mg/kg/day.

LOAEL = 500 mg/kg/day based on reduced bodyweight gain and food consumption, 

gastrointestinal toxicity, and decreased water 

consumption and urination. 

Developmental NOAEL = 500 mg/kg/day.

LOAEL = 1000 mg/kg/day based on an abortion, 

decrease in mean fetal weights, and elevated preand post-implantation loss.

870.3800

Reproduction and 

fertility effects

45012529 (1999)

Acceptable/guideline

0, 1000, 4000, or 16,000 ppm

F0(M): 0, 74.8, 297.1, or 1230.7 

mg/kg/day

F0(F): 0, 92.7, 373.5, or 1605.3 

mg/kg/day

F1(M): 0, 79.6, 322.9, or 1313.9 

mg/kg/day

Parental/Systemic 

NOAEL = 74.8-79.6 mg/kg/day (M) and 373.5-

413.5 mg/kg/day (F).

LOAEL = 297.1-322.9 mg/kg/day (M) and 

1605.3-1907.5 mg/kg/day (F) based on 

microscopic lesions of the stomach.

Reproductive

NOAEL = 373.5-413.5 mg/kg/day.

LOAEL = 1605.3-1907.5 mg/kg/day based on 
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 24 of 29

Table A.2.3. Subchronic, Chronic, and Other Toxicity Profile – Propoxycarbazone-sodium.

Guideline No./ 

Study Type

MRID No. (year)/ Classification 

/Doses Results

F1(F): 0, 103.8, 413.5, or 1907.5 

mg/kg/day

increased in diestrous/metestrous in females.

Offspring

NOAEL = 297.1-322.9 mg/kg/day (M) and 373.5-

413.5 mg/kg/day (F).

LOAEL = 1230.7-1313.9 mg/kg/day (M) and 

1605.3-1907.5 mg/kg/day (F) based on increased 

postimplantation loss and decreased live litter size 

in the F2 litters.

870.4100a

Chronic toxicity 

(rodent)

See 870.4300 See 870.4300

870.4100b

Chronic toxicity 

(dog)

45012513 (1998)

0, 2000, 10,000, or 25,000 ppm 

M: 0, 52.2, 258.0, or 630.7 mg/kg/

day

F: 0, 55.7, 235.5, or 605.4 mg/kg/

day

NOAEL = 630.7 mg/kg/day.

LOAEL > 630.7 mg/kg/day.

870.4200a 

Carcinogenicity 

(rat)

See 870.4300 See 870.4300

870.4200b

Carcinogenicity 

(mouse)

45012614 (1999)

Acceptable/guideline

0, 280, 1400, or 7000 ppm 

M: 0, 74.6, 369.0, or 1880.9 

mg/kg/day

F: 0, 126.2, 626.9, or 3106.1 

mg/kg/day

NOAEL = 369 mg/kg/day.

LOAEL = 1880.9 mg/kg/day based on decreased 

body weight gain combined with lower food 

efficiency in males.

No evidence of carcinogenicity.

870.4300

Combined Chronic 

Toxicity/

Carcinogenicity 

(rat)

45012514 (1999)

Acceptable/guideline

0, 1000, 10,000 and 20,000 ppm

M: 0, 43, 459, or 924 mg/kg/day

F: 0, 49, 525, or 1049 mg/kg/day

NOAEL = 43/49 mg/kg/day (M/F).

LOAEL = 459/525 mg/kg/day (M/F) based on 

decreased body weight and increased urinary pH 

(preceding histological changes in the kidney of 

rats in the mid- and high-dose groups such as: foci 

of mineralization of pelvis, dilated and cystic renal 

tubules filled with proteinaceous material, 

regenerative tubular epithelium, glomerular and 

interstitial fibrosis, and hyperplasia of the pelvic 

epithelium).

No evidence of carcinogenicity.

870.5100

Gene Mutation 

45012506 (1994)

Acceptable/guideline

0, 1.6, 8, 40, 200, 1000, or 5000 

μg/plate 

Negative

870.5100

Gene Mutation

45012516 (1999)

Acceptable/guideline

0, 16, 50, 158, 500, 1581, or 5000 

μg/plate

Negative

870.5100

Gene Mutation

45012528 (1999)

Acceptable/guideline

0, 0.25, 0.5, 1, 2, 4, or 8 μg/plate

Negative

870.5300

In vitro Chinese 

hamsterV79-HPRT

45012522 (1996)

Acceptable/guideline

0, 500, 1000, 2000, 3000, or 4000 

μg/mL

Negative

Cytogenetics 

870.5375

45012527 (1999)

Acceptable/guideline Negative
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 25 of 29

Table A.2.3. Subchronic, Chronic, and Other Toxicity Profile – Propoxycarbazone-sodium.

Guideline No./ 

Study Type

MRID No. (year)/ Classification 

/Doses Results

In vitro Chinese 

hamster

0, 625, 1250, or 2500 μg/mL

870.5375

In vitro Chinese 

hamster

45012613 (1996)

Acceptable/guideline

0, 500, 2500 or 5000 μg/mL 

Negative

870.5395

Hsd/Win: NMRI 

mouse bone marrow 

micronucleus

45012603 (1995)

Acceptable/guideline

2500 mg/kg

Negative

870.5550

Unscheduled DNA 

Synthesis

45012607 (1996)

Acceptable/guideline

0, 25, 100, 250, 500, 1000, 2000 or 

4000 μg/mL

Negative

870.6200a

Acute neurotoxicity 

screening battery

45012512 (1997)

Acceptable/guideline

2000 mg/kg

NOAEL = 800 mg/kg.

LOAEL = 2000 mg/kg based on a decrease in 

body weight gain in females.

870.6200b

Subchronic 

neurotoxicity 

screening battery

45012609 (1998)

Acceptable/guideline

0, 1000, 4000, or 20,000 ppm

M: 0, 64, 252, or 1321 mg/kg/day

F: 0, 79, 312, or 1651 mg/kg/day

NOAEL: 1321/1651 mg/kg/day (M/F).

LOAEL = not established.

870.7485

Metabolism and 

pharmacokinetics

45012631 (1999)

Acceptable/guideline

2 or 200 mg/kg

Absorption in male rats was ~25% after 

administration of 2 mg/kg and slightly decreased 

to ~21% with a single dose of 200 mg/kg. 

Absorption in female rats was slightly higher 

(~31%) after 2 mg/kg. Radiolabel position did not 

influence absorption. Plasma Tmax was rapid at 

~0.33 hours regardless of radiolabel position in 

rats that received 2 mg/kg and ~0.81 hours in rats 

that received 200 mg/kg. No bioaccumulation or 

tissue reservoirs were found. Plasma clearance 

was biphasic and rapid, with a T1⁄2 for the first 

phase of ~1.1 hours for the compound labeled in 

the triazol position and ~0.6 hours for the 

compound labeled in the phenyl position, 

regardless of dose. No radiolabel effects were 

noted in the second phase plasma T1⁄2, which was 

~11 hours at 2 and 200 mg/kg. The radiolabeled 

test material was primarily eliminated unchanged 

in the urine and feces (~75-88% of the 

administered dose), with essentially none

eliminated by the lungs. Of the absorbed 

radiolabeled test material, ~90% was excreted into 

the urine while the remaining was recovered from 

the bile. However, radiolabel position did 

influence the metabolic products. 

870.7800 

Immunotoxicity

49072705 (2012)

Acceptable/guideline

0, 600, 1800, or 5400 ppm

(0, 119, 370, or 1106 mg/kg/day)

NOAEL = 1106 mg/kg/day.

LOAEL = not established.
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 26 of 29

Attachment 3: Registered Propoxycarbazone End Use Products and Use Patterns.

Table A.3.1. Summary of Registered Uses for Propoxycarbazone-sodium.

Product 

Name Formulation Use Site

Maximum 

Application 

Rate and 

Application 

Method

PHI1

(days)

RTI2 

(days)

REI3

(hours)

Olympus 70% 

Water 

Dispersible

(264-809)

Dry Flowable

Wheat (spring, 

durum, winter), 

Triticale

0.04 lb a.i./A

Aerial, 

Groundboom

Preplant, 

preemergence, 

or 

postemergence

0 for 

forage and 

71 for 

grain/straw

Fall and 

spring 

applications 

allowed; 15 

days 

between 

apps for 

burndown

12

Olympus Flex 

Herbicide

(264-833)4

Wheat, Triticale

0.015 lb a.i./A

Aerial, 

Groundboom

Postemergence

30 for 

forage and 

71 for 

grain/straw

Only 1 app 

per 

growing 

season

24

Rimfire 

Herbicide

(264-847)4

Wheat, Triticale

0.011 lb a.i./A

Aerial, 

Groundboom

Postemergence

12

Rimfire Max 

Herbicide

(264-1099)4

Wheat, Triticale

0.009 lb a.i./A

Aerial, 

Groundboom

Postemergence

12

Olympus 

Rangeland 

Herbicide

(264-1074)

Pastures, 

Rangeland, 

Conservation 

Reserve 

Program land, 

Noncrop areas

0.05 lb a.i./A

Aerial, 

Groundboom

0.002 lb 

a.i./gal 

Handheld 

equipment 

Postemergence

Do not cut 

for hay 

within 7 

days of 

treatment

Not 

specified; 

fall and 

spring 

applications

12

1 PHI = preharvest interval.

2 RTI = retreatment interval. 

3 REI = restricted entry interval.

4 These products contain multiple a.i.’s. The other ai is mesosulfuron-methyl.
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 27 of 29

Attachment 4: Chronic Dietary Exposure Files.

The following dietary exposure files were reviewed by two peer reviewers (T. Bloom and J. 

VanAlstine) of the DESAC per DESAC SOP 2012.1. 

Filename: C:\Users\jlangsda\Documents\DEEM Runs for others\122019prop_Jan 28 2015.R08

Chemical: Propoxycarbazone sodium

RfD(Chronic): .748 mg/kg bw/day NOEL(Chronic): 74.8 mg/kg bw/day

RfD(Acute): 0 mg/kg bw/day NOEL(Acute): 0 mg/kg bw/day

Date created/last modified: 01-28-2015/10:53:03 Program ver. 3.16, 03-08-d

Comment: Chronic assessment with food and drinking water

-----------------------------------------------------------------------------------

 EPA Crop Def Res Adj.Factors Comment

 Code Grp Commodity Name (ppm) #1 #2 

---------- ---- ------------------------------- ---------- ------ ------ -------

1500381000 15 Triticale, flour 0.020000 1.000 1.000

1500381001 15 Triticale, flour-babyfood 0.020000 1.000 1.000

1500401000 15 Wheat, grain 0.020000 1.000 1.000

1500401001 15 Wheat, grain-babyfood 0.020000 1.000 1.000

1500402000 15 Wheat, flour 0.020000 1.000 1.000

1500402001 15 Wheat, flour-babyfood 0.020000 1.000 1.000

1500403000 15 Wheat, germ 0.020000 1.000 1.000

1500404000 15 Wheat, bran 0.020000 1.000 1.000

3100044000 31 Beef, meat 0.050000 1.000 1.000

3100044001 31 Beef, meat-babyfood 0.050000 1.000 1.000

3100045000 31 Beef, meat, dried 0.050000 1.920 1.000

3100046000 31 Beef, meat byproducts 0.300000 1.000 1.000

3100046001 31 Beef, meat byproducts-babyfood 0.300000 1.000 1.000 

3100048000 31 Beef, kidney 0.300000 1.000 1.000

3100049000 31 Beef, liver 0.300000 1.000 1.000

3100049001 31 Beef, liver-babyfood 0.300000 1.000 1.000

3200169000 32 Goat, meat 0.050000 1.000 1.000

3200170000 32 Goat, meat byproducts 0.300000 1.000 1.000

3200172000 32 Goat, kidney 0.300000 1.000 1.000

3200173000 32 Goat, liver 0.300000 1.000 1.000

3300189000 33 Horse, meat 0.050000 1.000 1.000

3500339000 35 Sheep, meat 0.050000 1.000 1.000

3500339001 35 Sheep, meat-babyfood 0.050000 1.000 1.000

3500340000 35 Sheep, meat byproducts 0.300000 1.000 1.000

3500342000 35 Sheep, kidney 0.300000 1.000 1.000

3500343000 35 Sheep, liver 0.300000 1.000 1.000

3600222000 36 Milk, fat 0.030000 1.000 1.000

3600222001 36 Milk, fat-baby food/infant formu 0.030000 1.000 1.000

3600223000 36 Milk, nonfat solids 0.030000 1.000 1.000

3600223001 36 Milk, nonfat solids-baby food/in 0.030000 1.000 1.000

3600224000 36 Milk, water 0.030000 1.000 1.000

3600224001 36 Milk, water-babyfood/infant form 0.030000 1.000 1.000

3600225001 36 Milk, sugar (lactose)-baby food/ 0.030000 1.000 1.000

8601000000 86A Water, direct, all sources 0.002800 1.000 1.000 New Wa

 Full comment: New Water #

8602000000 86B Water, indirect, all sources 0.002800 1.000 1.000 New Wa

 Full comment: New Water #
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 28 of 29

US EPA Ver. 3.16, 03-08-d

DEEM-FCID Chronic analysis for PROPOXYCARBAZONE SODIUM NHANES 2003-2008 2-day

Residue file name: C:\Users\jlangsda\Documents\DEEM Runs for others\122019prop_Jan 28 

2015.R08

 Adjustment factor #2 used.

Analysis Date 01-28-2015/10:53:47 Residue file dated: 01-28-2015/10:53:03

Reference dose (RfD, Chronic) = .748 mg/kg bw/day

COMMENT 1: Chronic assessment with food and drinking water

===============================================================================

 Total exposure by population subgroup

-------------------------------------------------------------------------------

 Total Exposure

 -----------------------------------

 Population mg/kg Percent of 

 Subgroup body wt/day Rfd 

-------------------------------------- ------------- ----------------

Total US Population 0.000320 0.0%

Hispanic 0.000375 0.1%

Non-Hisp-White 0.000319 0.0%

Non-Hisp-Black 0.000263 0.0%

Non-Hisp-Other 0.000336 0.0%

Nursing Infants 0.000176 0.0%

Non-Nursing Infants 0.000689 0.1%

Female 13+ PREG 0.000263 0.0%

Children 1-6 0.001101 0.1%

Children 7-12 0.000502 0.1%

Male 13-19 0.000303 0.0%

Female 13-19/NP 0.000246 0.0%

Male 20+ 0.000217 0.0%

Female 20+/NP 0.000206 0.0%

Seniors 55+ 0.000204 0.0%

All Infants 0.000530 0.1%

Female 13-50 0.000219 0.0%

Children 1-2 0.001513 0.2%

Children 3-5 0.000919 0.1%

Children 6-12 0.000539 0.1%

Youth 13-19 0.000274 0.0%

Adults 20-49 0.000220 0.0%

Adults 50-99 0.000203 0.0%

Female 13-49 0.000219 0.0%

-------------------------------------------------------------------------------
Propoxycarbazone-sodium Human Health Risk Assessment D423232

Page 29 of 29

Attachment 5: Propoxycarbazone-sodium IRLS Sheet.

Table A.5.1. Summary of US and International Tolerances and Maximum Residue Limits.

Residue Definition:

US Canada Mexico1 Codex

40 CFR 180.600

combined residues of the herbicide 

propoxycarbazone methyl 2-[[[(4,5-dihydro-4-

methyl-5-oxo-3-propoxy-1H-1,2,4-triazol-1-

yl)carbonyl]amino]sulfonyl] benzoate and its 

metabolite methyl 2-[[[(4,5-dihydro-3-(2-

hydroxypropoxy)-4-methyl-5-oxo-1H-1,2,4-

triazol-1-yl)carbonyl]amino]sulfonyl] benzoate 

Propoxycarbazole-sodium: 

benzoic acid, 2-[[[((1Z)-(4,5-

dihydro-4-methyl-5-oxo-3-

propoxy-1H-1,2,4-triazol-1-

yl)hydroxymethylene]amino]sul

fonyl]-methyl ester, sodium salt 

(1:1), including the metabolite 

benzoic acid, 2-[[[[4,5-dihydro3-(2-hydroxypropoxy)-4-

methyl-5-oxo-1H-1,2,4-triazol1-yl)carbonyl]amino]sulfonyl]-

methyl ester

None

Commodity Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico1 Codex

Grass, forage 20

Grass, hay 25

Wheat, forage 17

Wheat, grain 0.02 0.02

Wheat, hay 0.15

Wheat, straw 0.05

propoxycarbazone methyl 2-[[[(4,5-dihydro-4-

methyl-5-oxo-3-propoxy-1H-1,2,4-triazol-1-

yl)carbonyl]amino]sulfonyl]benzoate 

Commodity Tolerance (ppm) /Maximum Residue Limit (mg/kg)

US Canada Mexico1 Codex

Cattle, meat 0.05

Cattle, meat byproducts 0.3

Goat, meat 0.05

Goat, meat byproducts 0.3

Horse, meat 0.05

Horse, meat byproducts 0.3

Milk 0.05

Sheep, meat 0.03

Sheep, meat byproducts 0.3

Completed: M. Negussie; 09/15/14

1 Mexico adopts U.S. tolerances and/or Codex MRLs for its export purposes.