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SODIUM ASULAM FINAL WORK PLAN

The Agency is implementing the new registration review program, and will review each 

registered pesticide every 15 years to determine whether it continues to meet the Federal 

Insecticide, Fungicide and Rodenticide Act (FIFRA) standard for registration. Changes in 

science, public policy, and pesticide use practices will occur over time. 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 that statutory standard. The public 

phase of registration review begins when the initial docket is opened for each case. Information 

on this program is provided at: 

Introduction:

This is the Environmental Protection Agency’s (EPA or the Agency) Final Work Plan (FWP) 

for the registration review of asulam and sodium asulam (collectively referred to as asulam here 

after). This FWP includes the expected registration review timeline. The work plan also 

addresses public comments received concerning the Preliminary Work Plan (PWP) in the 

Summary Document, dated March 15, 2011, which was posted in the asulam registration review 

docket (EPA-HQ-OPP-2010-0783). The Summary Document provided information on what 

EPA knows about the pesticide and what additional risk analyses or information the Agency 

believes are needed to make a registration review decision.

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

Asulam is a selective, systemic, postemergent, carbamate herbicide used to control a variety of 

annual grasses and broadleaf weeds on sugarcane, Christmas tree plantations, ornamentals, turf 

(for sod only) and non-cropland areas (fencerows, lumberyards, storage areas, and industrial 

plant sites). In addition, asulam is used on spinach grown for seed in Washington and Oregon 

under Special Local Needs Registrations that were issued in 2008. Asulam has no registered 

residential uses. The only end-use formulation of asulam is a soluble/concentrate liquid (sodium 

salt of asulam). Tolerances have been established for residues of asulam in/on sugarcane and 

livestock commodities (40 CFR §180.360). Asulam was first registered in 1975. The 

reregistration eligibility decision (RED) was issued in 1995 and the tolerance reassessment 

eligibility decision (TRED) was issued in 2002.

Comments Received on Preliminary Work Plan:

The Agency received two comments during the 60-day public comment period for the asulam

PWP, which began on March 30, 2011 and ended on May 31, 2011 (EPA-HQ-OPP-2010-0783). 

The comments covered data compensation issues and technical corrections. These comments did 

not change the work plan or timeline established in the PWP. In the PWP, EPA also solicited 

comment on the specific topics of environmental justice, water body impairment, and trade 

irritants. No comments were received during the public comment period concerning these issues

either. This document makes final the work plan for the registration review of asulam. A

summary of the submitted comments and the EPA’s responses are presented in the “Summary of 

Comments and Agency Responses” section of this document. 
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Risk Assessment and Data Needs:

• The most recent comprehensive ecological risk assessment was conducted for the 

Reregistration Eligibility Decision (RED) of Asulam in 1995.

The Agency anticipates conducting a comprehensive ecological risk assessment, including an 

endangered species assessment, and an updated human health risk assessment for all uses of

asulam and its degradates of concern. Below is a summary of the issues relevant to the 

registration review of asulam.

Ecological Risk:

• The Agency will require the following data in order to conduct a comprehensive 

ecological risk and endangered species assessment for asulam:

o GLN 850.1350 – Aquatic invertebrate life cycle (freshwater)

o GLN 850.1400 – Fish early life stage (freshwater)

o GLN 850.2100 – Avian acute oral toxicity (passerine species)

o GLN 850.2300 – Avian reproduction 

o GLN 850.4100, 4150 – Terrestrial plant toxicity (using TEP, tier II)

• The Agency has not conducted an ecological risk assessment that supports a complete 

endangered species determination for asulam. The ecological risk assessment planned 

during registration review will allow the Agency to determine whether the use of asulam

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 (FWS) and/or National Marine 

Fisheries Service (NMFS) (the Services), as appropriate.

• Please refer to the document: Registration Review: Preliminary Problem Formulation for 

Environmental Fate and Ecological Risk, Endangered Species, and Drinking Water

Assessments for Asulam and Sodium Asulam, dated December 22, 2010 located in the 

docket for a more detailed discussion of the anticipated ecological risk assessment and 

data needs.

Human Health Risk:

• The most recent human health risk assessment for asulam was completed in 2002 to 

support the TRED. 

• An updated dietary assessment will reflect new toxicity data and incorporate the results 

from a new drinking water assessment.

• A residential exposure assessment that accounts for possible residential exposures to 

asulam use on non-cropland areas will be conducted to support registration review.

• An updated aggregate assessment will be conducted in order to capture any updates made 

to either the dietary or residential assessments.
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• The occupational risk assessment will also be updated to incorporate new toxicity data 

and reflect current assessment methodologies. 

• The tolerance expressions for asulam in 40 CFR §180.360 will be reviewed during 

registration review to ensure that they appropriately cover the metabolites and degradates 

of asulam and that they specify the residues to be measured for each commodity.

• The Agency will require the following studies, in accordance with the revised 40 CFR, 

Part 158, to conduct a comprehensive human health risk assessment for the registration 

review of asulam:

o GLN 870.6200 Neurotoxicity battery (acute and subchronic studies)

o GLN 870.7800 Immunotoxicity

• Please refer to the document: Asulam: Human Health Risk Scoping Document in Support 

of Registration Review dated March 2, 2011 in the docket for a more detailed discussion 

of the anticipated human health risk assessment and data needs.

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. Asulam is not 

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, sub-chronic 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 cyclist, 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 most recent registration decision, 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), asulam 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. 
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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 asulam. 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 website: http://www.epa.gov/endo/.

Registration Review for Asulam – Projected Registration Review Timeline

Timeline:

EPA has created the following estimated timeline for the completion of the registration review of 

asulam. 

Activities Estimated Date

Opening the Docket

Open Docket and Public Comment Period 2011 – March

Close Public Comment 2011 – May

Case Development

Final Work Plan 2011 – August

Issue DCI 2012 – April – June

Data Submission 2014 – April – June

Open Public Comment Period for Draft Risk Assessments 2015 – Oct. – Dec.

Close Public Comment Period 2016 – Jan. – March

Registration Review Decision

Open Public Comment Period for Proposed Registration Review 

Decision

2016 – April – June

Close Public Comment Period 2016 – July – Sept.

Registration Review Decision and Begin Post-Decision Follow-up 2017

Total (years) 6

1. Comment 

Summary of Comments and Agency Responses:

The asulam registration review docket was open for a 60-day comment period beginning on 

March 30, 2011. During the comment period, the FIFRA Endangered Species Task Force 

(FESTF) provided comment on data compensation obligations and one of the registrants, Aceto, 

made a usage correction. The following is a summary of the comments and EPA’s responses: 

The FIFRA Endangered Species Task Force (FESTF) submitted a comment that the Agency 

should ensure any company who is a registrant for asulam, but not a member of FESTF (or a 

company having met its data compensation obligations) provide a formal offer-to-pay to FESTF 

in conjunction with their support of the active ingredient.

EPA Response

The Agency thanks FESTF for its comment and will consider this information as it 

conducts the registration review process and makes its registration review decision.
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2. Comment 

The registrant, Aceto, noted an error in the Preliminary Problem Formulation for Asulam where 

the Agency indicated that it anticipates conducting a drinking water assessment from the use of 

asulam on potato storage facilities. Aceto notes that asulam has no current registered uses on 

potatoes or on/in potato storage facilities. 

EPA Response

The Agency notes the error; Agency records indicate that asulam is not currently 

registered for use on potatoes or on/in potato storage facilities. Therefore, potato or 

potato storage facilities will not be part of the Agency’s assessments for the registration 

review of asulam.

Summary of Data Gaps:

The table below summarizes all data needs for asulam as listed in the Asulam: Human Health 

Risk Scoping Document in Support of Registration Review dated March 2, 2011, and the 

Registration Review: Preliminary Problem Formulation for Environmental Fate and Ecological 

Risk, Endangered Species, and Drinking Water Assessments for Asulam and Sodium Asulam, 

dated December 22, 2010.

Guideline 

Number

Data Requirement Study 

Duration 

(Measured 

in months 

from 

receipt of 

GDCI)

Listed in 

PWP

Listed in 

FWP

850.1350 Aquatic invertebrate life cycle 

(freshwater)

12

The Agency’s 

anticipated data needs 

did not change and the 

Agency will issue a DCI 

for these studies

850.1400 Fish early life stage (freshwater) 12

850.2100 Avian acute oral toxicity (passerine 

species)

12

850.2300 Avian reproduction 24

850.4100, 

850.4150

Terrestrial plant toxicity, tier II 12

870.6200 Neurotoxicity battery (acute and 

subchronic)

12

870.7800 Immunotoxicity 12

Next Steps:

The Agency plans to require the above referenced studies through a generic data call-in, which is 

expected to be issued in late 2011. This new information will be used to conduct human health 

and ecological risk assessments for all registered uses of asulam.