2

Prometon Preliminary Work Plan – Table of Contents

Overview 3

Anticipated Data Needs 4

Statutory and Regulatory Authority 5

Chemical Facts 5

Use and Usage Information 6

Recent Actions 7

Anticipated Risk Assessments for Registration Review 7

Timeline 9

Next Steps 9

Appendix – Additional Areas Considered in Prometon’s Registration Review 10

References:

This Preliminary Work Plan summarizes the Environmental Protection Agency's current position 

based on the following documents:

1. Registration Review Problem Formulation for Prometon. Sternberg, Wente. February 26, 

2013.

2. Prometon Human Health Assessment Scoping Document in Support of Registration 

Review. Irwin, Britton, Donovan. March 15, 2013.

3. BEAD Chemical Profile for Registration Review: Prometon (080804). Phillips, Alsadek, 

Faulkner. October 10, 2012.

4. Prometon: Review of Human Incidents. Recore, Evans. November 20, 2012.

5. Prometon Focus Meeting Summary. Keller. November 7, 2012

These and other supporting documents for the prometon registration review case may be found in

the docket EPA-HQ-OPP-2013-0068 at http://www.regulations.gov.
3

OVERVIEW

The docket for prometon is now open, initiating the first public comment period for this 

registration review (docket number EPA-HQ-OPP-2013-0068). Prometon is a non-selective 

“bare-ground” herbicide registered for pre- and post-emergent applications to manage annual and 

perennial grasses and broadleaf weeds in parking lots, roadsides and under pavement. There are 

no registered agricultural uses, and the majority of prometon use is associated with weed control 

along fencerows and building perimeters, with smaller usage on industrial sites, rights-of-way 

areas, and residential areas. This Preliminary Work Plan (PWP) document explains what EPA's 

Office of Pesticide Programs knows about prometon, highlighting anticipated data and

assessment needs, identifying the types of information that would be especially useful to the 

Agency in conducting the review, and providing an anticipated timeline for completing 

prometon’s review.

The registration review process was designed to include a public participation component to 

solicit input from interested stakeholders. The Agency intends, by sharing this information in the 

docket, to inform the public of what it knows about prometon and what types of new data or 

other information would be helpful for the Agency to receive as it moves toward a decision on 

prometon. The Agency encourages all interested stakeholders to review the PWP and Appendix 

and to provide comments and additional information that will help the Agency’s decisionmaking process for this chemical. In addition to general areas on which persons may wish to 

comment, there are some areas identified in the PWP and Appendix about which the Agency 

specifically seeks comments and information. Interested stakeholders could include: 

environmental non-profit or interest groups; pesticide manufacturers; agricultural labor or 

commodity groups; commercial, institutional, residential, and other users of pesticides; or the 

public at large.

The Prometon Reregistration Eligibility Decision (RED) specified that all residential use of 

prometon was to be cancelled. On January 2, 2013 a notice of receipt of requests for 

amendments to terminate uses for certain pesticide registrations was published in the Federal 

Register [EPA-HQ-OPP-2012-0548; FRL-9372-3]; this included a notice of request to cancel all 

residential uses for prometon. Should no request to withdraw the cancellation of all residential 

use of prometon be received, the cancellation would become effective July 1, 2013 and would 

void the need for a residential and aggregate risk assessment during registration review. The 

Preliminary Work Plan begins by listing the anticipated data needs for prometon. Next, it 

discusses the statutory and regulatory authority for Registration Review. Then the document 

provides prometon’s chemical facts, use and usage information, recent actions, the anticipated 

risk assessments, and a projected registration review timeline. Finally, the Appendix to this 

document includes identification and discussion of some areas that are considered generally in 

Registration Review along with some additional chemical case-specific information.
4

ANTICIPATED DATA NEEDS

Table 1 below summarizes anticipated data needs for prometon. For additional discussion of the 

anticipated data needs, see the Registration Review Problem Formulation for Prometon and 

Prometon Human Health Assessment Scoping Document in Support of Registration Review.

Table 1: Anticipated Data Needs for Prometon’s Registration Review1

Guideline 

Number Study Title Test Material

Estimated 

Timeframe

(Months from 

receipt of DCI)

835.4300 Aerobic Aquatic Metabolism TGAI 24

835.4400 Anaerobic Aquatic Metabolism TGAI 24

850.1075 Fish Acute Toxicity, fathead minnow2 TGAI 12

850.1400 Fish Early Life Stage Toxicity Test, rainbow trout2 TGAI 12

850.2100 Avian oral toxicity (passerine species) TGAI 12

850.4400 Aquatic plant toxicity test using Lemna spp. TGAI 12

850.4500 Algal toxicity TGAI 12

850.4550 Cyanobacteria toxicity TGAI 12

850.6100

Environmental Chemistry Methods and Associated 

Independent Laboratory Validation for soil, 

sediment, and water

TGAI 12

870.3465 90-day inhalation toxicity3 TGAI 24

TGAI = technical grade active ingredient

As part of the Problem Formulation for Prometon, the Agency considers Guideline 850.1350, 

Aquatic invertebrate life cycle (salt water) a low value study. Given that prometon is slightly 

toxic to aquatic animals on an acute basis, and there is no evidence to indicate that 

estuarine/marine animals are substantially more sensitive to prometon than freshwater animals, 

fulfilling this data requirement would seem to have a low potential to add value to the 

Registration Review risk assessment. At this time, the Agency does not anticipate requiring this 

study for this registration review as the acute to chronic ratio extrapolation from the daphnid

study is expected to be used.

Additionally, the Agency also considers Guideline 850.1400 – Fish Early Life Stage Toxicity 

Test (on Esturine/Marine Species) a low value study. Given that prometon is slightly toxic to 

 1 On June 27, 2012, EPA announced certain revisions in harmonized guideline series 850 – Ecological Effects Tests 

– including renumbering and other designations or changes for some guideline studies. See “Final Test Guidelines; 

OCSPP 850 Series; Notice of Availability” 77 FR 38282, June 27, 2012. 

http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OPPT-2009-0154-0028 2 Either an acute toxicity test with fathead minnow using GDLN 850.1075 or a chronic test with rainbow trout, 

GDLN 850.1400, is anticipated to be required. These data would be used by the Agency to generate an acute to 

chronic ratio (ACR) for evaluating risk to estuarine/marine fish species from chronic exposure to prometon. 3 For the inhalation toxicity study, a test of 28 days duration should be sufficient to satisfy this anticipated data 

requirement.
5

aquatic animals on an acute basis, and there is no evidence to indicate that estuarine/marine 

animals are substantially more sensitive to prometon than freshwater animals, fulfilling this data 

requirement has a low potential to add value to the Registration Review risk assessment. In the 

absence of this data, toxicity to estuarine/marine fish from chronic exposure to prometon may be 

characterized using toxicity data for freshwater fish exposed to prometon or toxicity data for 

estuarine/marine fish exposed to other triazines. 

STATUTORY AND REGULATORY AUTHORITY

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review program. All 

pesticides distributed or sold in the United States (U.S.) generally must be registered by the 

Environmental Protection Agency (EPA or the Agency), based on scientific data showing that 

they will not cause unreasonable risks to human health or the environment when used as directed 

on product labeling. The registration review program is intended to make sure that, as the ability 

to assess risk evolves and as policies and practices change, all registered pesticides continue to 

meet the statutory standard of no unreasonable adverse effects to human health or the 

environment. Changes in science, public policy, and pesticide use practices will occur over time. 

Through the registration review program, the Agency periodically reevaluates pesticides to make 

sure that as change occurs, products in the marketplace can be used safely. Information on this 

program is provided on EPA’s website.

4

The Agency is implementing the registration review program pursuant to Section 3(g) of the 

Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and will review each registered 

pesticide every 15 years to determine whether it continues to meet the FIFRA standard for 

registration. The regulations governing registration review begin at 40 CFR 155.40. The 

Agency will consider benefits information and data as required by FIFRA. The public phase of 

registration review begins when the initial docket is opened for each case. The docket is the 

Agency’s opportunity to state what it knows about the pesticide and what additional risk analyses 

and data or information it believes are needed to make a registration review decision. After 

reviewing and responding to comments and data received in the docket during this initial 

comment period, the Agency will develop a Final Work Plan (FWP) and anticipated schedule for 

the registration review of prometon.

Table 2 provides a summary of the current regulatory status of (chemical).

Table 2: PROMETON CHEMICAL FACTS

PC code 080804

Case Number 2545

CAS Number 1610-18-0

Year first registered 1959

Pesticide Type herbicide

Chemical class triazine

Reregistration Eligibility 

Decision (RED)

March 2008

 4 http://www.epa.gov/oppsrrd1/registration_review/
6

Tolerance Reassessment 

Eligibility Decision 

(TRED)

Not applicable

Cumulative group Not applicable as prometon is not a part of a cumulative group.

40 CFR Citation There are no established tolerances for prometon because there are 

no registered food or feed uses for prometon.

Dual-use Conventional pesticidal uses only.

Non-pesticidal uses No non-pesticidal uses of prometon.

Pesticide Re-evaluation 

Division, Chemical 

Review Manager

Steven Snyderman, snyderman.steven@epa.gov, 703-347-0249

Registration Division, 

Product Manager

Kable Davis, davis.kable@epa.gov, 703-347-0249

USE AND USAGE INFORMATION

Table 3 summarizes the use and usage information for (chemical). Please see the BEAD 

Chemical Profile for Registration Review: Prometon (080804) in the registration review docket 

for more details.

Table 3: USE AND USAGE INFORMATION

Summary of Use Non-selective triazine herbicide registered for use to control 

broadleaf and grass weeds when applications are made prior to 

weed emergence or postemergence to the weed; however, woody 

brush or tree weeds are not controlled unless prometon is applied in 

a mix of oil such as diesel fuel.

Use Sites Use sites are typically those that require total vegetation control 

resulting in bare ground for between one and two years following a 

single application. Not currently registered for agricultural use.

Non-Agricultural use sites include domestic dwellings (outdoor), 

commercial/industrial areas, drainage ditch banks, farm buildings 

(indoor/outdoor), ornamental turf, residential areas, uncultivated 

areas, airports/landing fields, fencerows/hedgerows, rights-of-way, 

paths/patios, paved areas (private roads/sidewalks), recreational 

areas, and utility poles. 

Summary of Usage The majority of prometon use is associated with weed control along 

fencerows and building perimeters, with smaller usage on other 

industrial sites (i.e., pump stations, tanks, pipelines, pipe storage 

areas), rights-of-way areas (i.e., airports, railroads, and medians), 

and residential areas. Based on usage information provided by the 

registrant for the 2008 RED, total annual sales of prometon are 

approximately 550,000 – 600,000 pounds of a.i.: approximately 

60% is applied to building perimeters or fencerows; 30% is applied 

to industrial sites; and <10% is applied to rights-of-way areas.

Formulation Type(s) Granules, peletted/tabulated, wettable powder, emulsifiable, 
7

flowable soluble concentrate, and solution ready-to-use.

Application Method(s) Boom sprayers, handheld nozzle or wand sprayers, knapsack 

sprayers, and granular spreaders.

Technical Registrant(s) Makhteshim-Agan of North America, Inc.

No. of Registrations 21 Section 3 products5

Restricted Use No

Guidance for Commenters: Additional areas of use and usage related information

requested for this registration review, and of particular interest to EPA, are described below.

• Information such as pounds active ingredient applied, application methods, application 

rates for risk drivers, and application timing on: domestic dwellings (outdoor), 

commercial/industrial areas, drainage ditch banks, farm buildings (indoor/outdoor), 

ornamental turf, residential areas, uncultivated non-agricultural areas, airports/landing 

fields, fencerows/hedgerows, non-agricultural rights-of-way, paths/patios, paved areas 

(private roads/sidewalks), and recreational areas, could assist assessment of the 

importance of prometon.

• Confirmation of the following label information: sites of application; formulations;

application methods and equipment; maximum application rates; frequency of 

application, application intervals, and maximum number of applications per year; and

geographic limitations on use.

• Use distribution (e.g., acreage and geographical distribution of relevant use sites)

• Median and 90th percentile reported use rates (lbs ai/A) from usage data – national, state, 

and county

• Application timing (date of first application and application intervals) – national, state, 

and county

• Usage/use information for non-agricultural uses

• State or local use restrictions

• Foreign technical registrants not listed above who supply technical prometon to the US 

market

RECENT ACTIONS

On January 2nd, 2013 a notice of receipt of requests for amendments to terminate uses for certain 

pesticide registrations was published in the Federal Register [EPA-HQ-OPP-2012-0548; FRL9372-3]; this included a notice of request to cancel all residential uses for prometon. Should no 

requests to withdraw the cancellation of all residential uses of prometon then the cancellations

would become effective July 1, 2013 and would void the need for a residential and aggregate risk 

assessment during registration review.

ANTICIPATED RISK ASSESSMENTS FOR REGISTRATION REVIEW

The most recent comprehensive human health risk assessment for prometon was completed in 

2008 in preparation for the Reregistration Eligibility Decision. The most recent ecological and 

 5 Section 3 product labels can be obtained from the Pesticide Product Label System (PPLS) website 

(http://oaspub.epa.gov/pestlabl/ppls.home).
8

environmental fate risk assessment was completed for the same purpose. Findings and 

conclusions from these risk assessments are summarized in the Registration Review Problem 

Formulation for Prometon and Prometon Human Health Assessment Scoping Document in 

Support of Registration Review.

During registration review, the Agency anticipates the need to conduct a comprehensive

ecological risk assessment, including an endangered species assessment, for all uses of

prometon. For human health, EPA anticipates the need to conduct revised drinking water and 

residential risk assessments during registration review. If toxicological endpoints or points of 

departure are revised based on the data that are anticipated to be required for registration review, 

they will be considered in the new assessments, as well as any changes to the standard operating 

procedures or default exposure assumptions.

Table 4 below summarizes the anticipated registration review risk assessments based on the 

EFED Problem Formulation and HED Scoping Document.

Table 4: Anticipated Risk Assessments for Prometon’s Registration Review

Type of Risk Assessment Conduct? Notes

Ecological and Environmental Fate

Comprehensive ecological 

(species to be assessed 

include terrestrial and aquatic 

organisms), including 

endangered species 

Y Prometon degradates GS-11526 and GS-14626 have 

been determined to be approximately as toxic as the 

parent prometon to aquatic organisms; therefore these 

degradates, along with the parent, will be considered 

stressors of concern for the ecological risk assessment

Incidents Will check for 

updates

For a discussion of prometon’s reported ecological 

incidents, see page 17 of the Problem Formulation.

Human Health

Dietary

Food N Prometon is not currently registered for use on food

or feed.

Drinking water Y

Occupational

Handlers (mixers, loaders, 

applicators)

N There are currently no significant changes identified 

which would require an update of the occupational 

Post-application N exposure risk assessment since the 2008 RED.

Residential

Handlers Y Should remaining residential uses be cancelled, a 

residential handler assessment would no longer be 

necessary.

Post-application N Due to the nature of its use, significant dermal 

exposure from recently treated areas is not 

anticipated.
9

Other

Aggregate N Evaluates the combined risk from dietary and 

residential exposures. An aggregate assessment may 

be required should the cancellation of all residential 

uses of prometon not be finalized.

Cumulative N Although prometon is a triazine chemical, it is 

specifically a methoxy triazine and not included in the 

triazine cumulative assessment.

Tolerances N Tolerances are not established for prometon since it is 

not registered for use on food or feed at this time.

Incidents Will check for 

updates

For a discussion of prometon’s reported human 

incidents, see page 6 of the Scoping Document.

Guidance for Commenters: Additional ecological information requested for this 

registration review, and of particular interest to EPA, is described below.

• Ecological incidents (non-target plant damage and avian, fish, reptilian, amphibian and 

mammalian mortalities) not already reported to the Agency.

• Water quality monitoring data (see Appendix for further details).

TIMELINE

EPA has created the following estimated timeline for the completion of prometon’s registration

review in Table 5 below.

Table 5: Registration Review for Prometon – Projected Registration Review Timeline

Activities Estimated Date

Opening the Docket

Open Docket and 60-day Public Comment Period 2013 - March

Close Public Comment 2013 - May

Case Development

Final Work Plan 2013 - August

Issue DCI 2014 – April - June

Data Submission 2016 – April - June

60-day Public Comment Period for Draft Risk Assessments 2017 – Oct. –Dec.

Registration Review Decision

60-day Public Comment Period for Proposed Registration Review 

Decision

2018 – April - June

Registration Review Decision and Begin Post-Decision Follow-up 2019

Total (years) 6

NEXT STEPS

After the 60-day public comment period closes, the Agency will review and respond to any 

comments received in a timely manner and then issue a Final Work Plan for the registration 

review of prometon.
10

Appendix – Additional Areas Considered in Prometon’s Registration Review

PUBLIC COMMENTS AND FEEDBACK:

Guidance for Commenters: The areas below highlight topics of special interest to the Agency 

where your comments, data submissions, or reference to sources of additional information could 

be of particular use.

Trade Irritants:

Through the registration review process, the Agency intends to solicit information on trade 

irritants and, to the extent feasible, take steps toward facilitating irritant resolution. The Agency 

will work to harmonize tolerances and international maximum residue limits (MRLs) and may 

modify tolerance levels to do so, when possible. Growers and other stakeholders are asked to 

comment on any trade irritant issues resulting from lack of MRLs or disparities between U.S. 

tolerances and MRLs in key export markets, providing as much specificity as possible regarding 

the nature of the concern. Because prometon is not registered for food/feed uses in the U.S., it 

has no U.S. tolerances; therefore, the Agency does not anticipate any trade irritant issues for it.

Water Quality:

Prometon is not identified as a cause of impairment for any water bodies listed as impaired under 

section 303(d) of the Clean Water Act6

. In addition, no Total Maximum Daily Loads (TMDL) 

have been developed for prometon7

. More information on impaired water bodies and TMDLs 

can be found at the Agency’s website8

. The Agency invites submission of water quality data 

for this pesticide. To the extent possible, data should conform to the quality standards in 

Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and 

Other Water Quality Data in OPP’s Registration Review Risk Assessment and Management 

Process9 in order to ensure they can be used quantitatively or qualitatively in pesticide risk 

assessments.

Environmental Justice:

EPA seeks to achieve environmental justice, the fair treatment and meaningful involvement of all 

people, regardless of race, color, national origin, or income, in the development, implementation, 

and enforcement of environmental laws, regulations, and policies. To help address potential 

environmental justice issues, the Agency seeks information on any groups or segments of the 

population who, as a result of their location, cultural practices, or other factors, may have 

atypical, unusually high exposure to prometon compared to the general population. Please 

comment if you are aware of any sub-populations that may have atypical, unusually high 

exposure compared to the general population.

 6 http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885

7

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id=885&p_pollutant_

group_name=PESTICIDES

8 http://www.epa.gov/owow/tmdl/

9 http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm
11

ENDANGERED SPECIES:

A risk assessment that supports a complete endangered species determination has not been 

conducted for prometon. The ecological risk assessment planned during registration review will 

allow the Agency to determine whether prometon’s use has “no effect” or “may affect” federally 

listed threatened or endangered species (listed species) or their designated critical habitats. 

When an assessment concludes that a pesticide’s use “may affect” a listed species or its 

designated critical habitat, the Agency will consult with the U.S. Fish and Wildlife Service 

and/or National Marine Fisheries Service (the Services), as appropriate.

ENDOCRINE DISRUPTOR SCREENING PROGRAM:

As required by FIFRA and 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 prometon, 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), prometon 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 and 9 inert ingredients. Prometon is 

not among the group of 58 pesticide active ingredients on the initial list to be screened under the 

EDSP. Accordingly, as part of registration review, EPA will issue future EDSP orders/data callins, requiring the submission of EDSP screening assays for prometon. For further information 

on the status of the EDSP, the policies and procedures, the list of 67 chemicals, future lists, the 

test guidelines and the Tier 1 screening battery, please visit our website10.

 10 http://www.epa.gov/endo/
12

HUMAN STUDIES:

Occupational and Residential

Past prometon risk assessments rely in part on data from studies in which adult human subjects 

were intentionally exposed to a pesticide to determine their dermal and inhalation exposure. 

Many such studies, involving exposure to many different pesticides, comprise generic pesticide 

exposure databases such as the Pesticide Handlers Exposure Database (PHED), and the Outdoor 

Residential Exposure Task Force (ORETF) Database. EPA has reviewed all the studies 

supporting these multi-pesticide generic exposure databases, and has found no clear and 

convincing evidence that the conduct of any of them was either fundamentally unethical or 

significantly deficient relative to the ethical standards prevailing at the time the research was 

conducted. All applicable requirements of EPA’s Rule for the Protection of Human Subjects of 

Research (40 CFR Part 26) have been satisfied, and there is no regulatory barrier to continued 

reliance on these studies.