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 The 1995 risk assessment addressed exposures and risks associated with occupational and 

residential uses of starlicide. The assessment recommended numerous risk mitigation and 

labeling measures. Given implementation of the recommended label restrictions and personal 

protective equipment (PPE) requirements for workers, the 1995 assessment determined that 

exposures to starlicide from registered uses would not present risks of concern. 

HED’s problem formulation conclusions are as follows. 

1) A dietary exposure assessment was not conducted for the 1995 assessment because starlicide 

was determined to be a non-food use pesticide. However, HED has determined that under 

current labels uses in livestock and poultry feedlots constitute a food use. Therefore, EPA is 

working with the registrants to revise the labels to include language that is sufficiently 

restrictive to preclude exposure to livestock. Consequently, a dietary assessment will not be 

required for Registration Review. 

2) A drinking water exposure assessment is not required for Registration Review based on use 

patterns. 

3) A quantitative residential exposure assessment was not conducted for the 1995 assessment. 

However, use in accordance with current labels could result in post-application exposure to 

children. Therefore, EPA is working with the registrants to revise the labels to include 

language that is sufficiently restrictive to preclude residential postapplication exposure. 

Consequently, a residential exposure assessment will not be required for Registration 

Review. 

4) The occupational exposure assessment needs to be revised for Registration Review to include 

a quantitative assessment of exposures to occupational handlers and workers re-entering 

treated sites. 

5) An aggregate risk assessment is not required for Registration Review on the presumption that 

labels will be adequately revised to preclude dietary or residential exposures. 

6) A subchronic dermal toxicity study is required for Registration Review based on the 

registered uses and application methods. 

7) Developmental toxicity studies in the rat and rabbit are required for Registration Review for 

non-food use pesticides under 40 CFR Part 158. 

8) A reproduction toxicity study in rats is required for Registration Review for non-food use 

pesticides under 40 CFR Part 158. 

9) An immunotoxicity study and acute and subchronic neurotoxicity studies are required for 

Registration Review under 40 CFR Part 158 as a part of the new data requirements for 

registration of a pesticide (food and non-food uses). 
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Introduction 

HED has evaluated the existing human health risk assessments for starlicide to determine 

whether sufficient data are available and whether a new human health risk assessment is needed 

to support Registration Review. HED has considered the most recent risk assessments for 

starlicide, updates to its toxicity, exposure and usage databases, and current Agency science 

policies and risk assessment methods. 

Use Profile 

Starlicide is an avicide used for control of predatory birds i.e., birds preying on newborn 

livestock, Federally-designated Threatened or Endangered Species, and other species designated 

to be in need of special protection. It is also used to control birds causing health, nuisance, or 

economic problems. Use sites vary by species but include livestock and poultry feedlots, 

buildings, non-crop areas, Federal and State protected areas, coastal areas, and bird staging and 

roosting sites. Starlicide is slow-acting and highly toxic to target species, with death occurring 

1-3 days after ingestion. Starlicide is a restricted use pesticide to be sold to and used only 

certified applicators or persons under their direct supervision. Starlicide is applied by manual or 

mechanical broadcast of treated bait (e.g., grain, corn, bread crumbs) and by placement of treated 

bait in feeding stations (i.e., small piles or bait containers). Starlicide is not available for use by 

homeowners. However, there may be potential for post-application exposure to residents 

entering treated areas. 

Chemical Identity 

Table 2.1. Starlicide Nomenclature

Chemical structure 

Common name Starlicide 

IUPAC name 3-Chloro-4-methylaniline 

CAS name 3-Chloro-4-methylbenzenamine hydrochloride 

CAS registry number 7745-89-3 

Hazard Identification/Toxicology 

Starlicide was determined to be a low volume, minor use pesticide for the 1995 risk 

assessment. HED waived the guideline requirements for repeat dose oral and dermal toxicity 

studies for non-food use pesticides due to low use and low exposure expected from uses actively 

registered in 1995. Consequently, there are very few toxicological studies available for 

starlicide. Developmental and reproduction toxicity studies are not available for starlicide. 

Newly required neurotoxicity and immunotoxicity studies are not available for starlicide. A non-
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guideline chronic cancer study conducted by the National Cancer Institute (NCI) with mice and 

rats indicates that starlicide is not a carcinogen. Available mutagenicity tests indicate that 

starlicide is not mutagenic. 

Based on available acute toxicity data, starlicide is moderately acutely toxic via the oral 

route (Category II), minimally toxic via the dermal route (Category IV) and moderately to 

severely irritating, both dermally and ocularly (Category I). OPP did not require an acute 

inhalation study for starlicide citing the fact that the technical material is incorporated into 

viscous bait. However, starlicide was placed in toxicity Category I for acute inhalation based on 

the severely irritating properties observed in the ocular and dermal irritation studies. 

 Toxicity points of departure (PODs) were not selected for the 1995 risk assessment. 

PODs for dietary exposure were not required because the registered uses were determined to be 

non-food. Quantitative occupational and residential exposure assessments were not required for 

starlicide because the Agency determined that there was low potential for exposure both to 

occupational handlers during use and to persons entering treated sites after application is 

complete. 

Data Requirements

Carcinogenicity and subchronic and chronic oral toxicity studies are not required for nonfood use pesticides. However, based on HED’s evaluation of existing labels, registered use of 

starlicide in livestock and poultry feed lots is considered a food use. EPA is working with the 

registrants to revise the labels to include language that is sufficiently restrictive to preclude 

exposure to livestock. If these labeling changes were not made, Subchronic Oral Toxicity 

(870.3100, 870.3150), Chronic Oral Toxicity (870.4100) and Carcinogenity (870.4200) studies 

would be required for Registration Review. As noted, an NCI cancer study with mice and rats 

has previously been submitted. This study was not required for registration of starlicide in 1995 

and has not been officially reviewed to determine its adequacy based on OCSPP Harmonized 

Test Guidelines Series 870. If carcinogenicity studies are required for registration review, the 

available NCI cancer study will be evaluated to determine whether it is an acceptable guideline 

study that can be used for risk assessment. 

HED’s label and use evaluation also indicates the potential for repeated exposures to both 

occupational handlers and workers who re-enter treated sites. Consequently, the following 

guideline toxicity studies are required for Registration Review of starlicide; Acute Inhalation 

Toxicity (870.1300), Subchronic Dermal Toxicity (870.3250), Prenatal Developmental Toxicity 

(870.3700), Reproduction And Fertility Effects (870.3800), Neurotoxicity Battery (870.6200), 

and Immunotoxicity (870.7800). A neurotoxicity battery and an immunotoxicity study are 

required for food and non-food use pesticides in accordance with the revised 40 CFR Part 158 

Toxicology Data Requirements. 

Conclusions

The HED Registration Review team has re-evaluated the toxicity analysis conducted for 

the starlicide occupational and residential exposure assessment conducted in 1995. Based on this 
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evaluation, all of the toxicological data requirements for non-food use pesticides are applicable 

and the required studies need to be submitted by the registrant for Registration Review. In 

addition, dermal and inhalation PODs for use in a quantitative occupational exposure assessment 

need to be identified based on the required toxicity data. 

Dietary and Drinking Water Exposure 

The risk assessment conducted for the RED in 1995 designated registered uses of 

starlicide as nonfood with the stipulation that uses allowing application to areas where food or 

feed crops are grown be removed from existing labels and that labels be revised to include a 365 

day prohibition on grazing animals and growing crops on lands treated with starlicide baits. 

Under these conditions, a dietary exposure assessment was not required for the RED. A 

quantitative drinking water assessment was also not required for the RED based on limited use 

patterns and restrictions against placement of treated baits within 50 feet of water bodies. 

Data Requirements 

 Since the Agency considered the uses of starlicide to be non-food in 1995, residue 

chemistry data were not required. However, HED has determined that existing broadcast use of 

starlicide in livestock and poultry feed lots is considered a food use under current criteria for 

determination what constitutes a food use. Therefore, EPA is working with starlicide registrants 

to revise the labels to include language that is sufficiently restrictive to preclude dietary 

exposure. Therefore, data applicable to food use pesticides are not required for Registration 

Review. 

Conclusions

 While a dietary exposure assessment was not required for the 1995 assessment based on a 

non-food use determination, current product labels and several Special Local Needs (SLN) 

registrations issued since completion of the 1995 assessment provide for broadcast application of 

treated bait (e.g., grain, corn, breadcrumbs) to feed lots for livestock and poultry. These 

broadcast feedlot uses have been evaluated and are considered to be food uses under current 

criteria. In order for starlicide to be designated a non-food use pesticide, the feed lot use must be 

modified to practically and adequately ensure that livestock will not be exposed to treated bait. 

As previously noted, EPA is working with the registrants to revise the labels as needed to 

preclude a food use determination. 

Residential Exposure 

 Starlicide is a restricted use pesticide limited to use by certified professional applicators. 

It cannot be purchased or applied by homeowners. Therefore, a residential handler exposure 

assessment was not required for the 1995 assessment. While the RED assessment indicated that 

there was potential exposure to residents entering treated sites after application, the Agency 

concluded that post-treatment residential exposures would be minimal based on use restrictions, 

and a residential post-application exposure assessment was not required. 
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Conclusions

Based on a review of currently registered labels and use patterns, HED believes that there 

may be potential for post-application exposure to residents entering treated areas. HED’s review 

indicates that label restrictions are clearly intended to prevent such exposure. However, current 

label restrictions are inadequate to limit exposure sufficiently to preclude the need for a 

residential post-application exposure assessment. Therefore, the starlicide registrants are 

working with EPA to revise existing labels with language that is sufficiently restrictive to 

preclude exposure to children. 

 

Aggregate Exposure 

The aggregate risk assessment integrates the assessments conducted for dietary/drinking 

water and residential exposure. An aggregate assessment was not conducted for the 1995 RED 

since starlicide uses were determined to be non-food and residential exposures were 

qualitatively determined to be minimal and not of concern. 

Conclusions

Given the registrants’ ongoing work to revise labels to adequately limit exposure to 

livestock and children, and aggregate assessment is not required for Registration Review. 

Occupational Exposure 

 The Agency determined in 1995 that a quantitative assessment of occupational handler 

and post-application exposure was not required based label restrictions that limit use to certified 

applicators or persons under their direct supervision, use patterns that result in limited exposure, 

and requirements for use of personal protective equipment. The Agency expressed concerns for 

inhalation exposure to occupational handlers who mix and load large volumes of starlicide 

concentrate. To address those concerns, EPA imposed label restrictions requiring respiratory 

protection for workers handling one pound or more of starlicide concentrate. The Agency 

concluded in 1995 that handling small volumes of starlicide would result in minimal exposure 

and that when large volumes are needed, the respirator requirements would sufficiently minimize 

the risk of inhalation exposure to workers. Based on these considerations, a risk assessment was 

not required for occupational exposures. 

Conclusions

A quantitative occupational exposure assessment is required for Registration Review of 

starlicide. A review of actively registered products and SLN labels indicates that there is 

potential for repeat exposure to occupational handlers and to workers who reenter treated sites. 

Labels provide for repeated manual and mechanical broadcast application of treated bait (e.g., 

grain, corn, bread crumbs) to large areas. Under current SOPs, a quantitative assessment of 

dermal and inhalation exposure and risk to occupational handlers is required based on 

application methods that are anticipated to result in occupational exposures. A qualitative review 

of potential post-application exposure scenarios is also required. Based on that review, a 
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quantitative assessment of post-application exposure to workers may also be required. The 

occupational assessment needs to incorporate PODs selected based toxicity data required for 

Registration Review. 

Incident Report 

An updated incident report was conducted for starlicide for Registration Review. From 

2006 to 2011, there were no incident cases reported for starlicide in either the main or aggregate 

Incident Data Systems. Based on the lack of reported incident cases, 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. 

Endocrine Disruption

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, 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), starlicide 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. Starlicide 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 starlicide. For further information on 
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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/. 

Cumulative 

EPA does not have, at this time, available data to determine whether starlicide has a 

common mechanism of toxicity with other substances. EPA has not made a common mechanism 

of toxicity finding for starlicide and any other substances and, starlicide does not appear to 

produce a toxic metabolite produced by other substances which have tolerances in the U. S. 

Therefore, EPA has not assumed that starlicide has a common mechanism of toxicity with other 

substances. 

Human Studies 

The risk assessment for starlicide did not rely on data from studies in which adult human 

subjects were intentionally exposed to a pesticide or other chemical. However, future 

occupational and/or residential assessments conducted for registration review of starlicide will 

use data contained in HED’s generic pesticide exposure databases such as Pesticide Handlers 

Exposure Database (PHED), the Agricultural Reentry Task Force (ARTF) Database and the 

Outdoor Residential Exposure Task Force (ORETF) Database). Recommended unit exposures 

for occupational handler assessments have generally been derived only from PHED. However, 

recently both the ORETF and AHETF have produced pesticide handler exposure monitoring data 

that the Agency is using in place of PHED (http://www.epa.gov/pesticides/science/handlerexposure-data.html). As more reliable data become available, the Agency will continue to 

replace existing data and new exposure monitoring data will be incorporated into HED’s 

Registration Review assessments as necessary. 

EPA has reviewed all the studies supporting the multi-pesticide generic exposure 

databases used to derive recommended unit exposures for occupational and residential exposure 

assessments 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. 

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 to Address Environmental Justice in Minority Populations and Low-Income 

Populations," http://www.eh.doe.gov/oepa/guidance/justice/eo12898.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 
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pesticide use in a residential setting. 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 postapplication 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. 

Conclusions/Future Actions Needed 

The actions needed in the future Registration Review for starlicide are listed below. 

Hazard Identification and Endpoint Selection

The following toxicity studies required for non-food use pesticides are not available for starlicide 

and need to be submitted for Registration Review: acute inhalation, subchronic dermal, prenatal 

developmental, reproduction, neurotoxicity, and immunotoxicity. Based on current OPP 

standards, PODs for dermal and inhalation exposure endpoints, selected based on the required 

toxicity data, are needed for adequate assessment of occupational exposure and risk. 

Dietary and Drinking Water Exposure and Risk

USDA has agreed to revise the labels as needed to preclude a food use determination. 

Therefore, dietary and drinking water exposure assessments will not be required for Registration 

Review. 

Residential Exposure and Risk

USDA has agreed to revise existing labels to more practically and adequately restrict residential 

post-application exposure. Therefore, a quantitative residential exposure assessment is not 

required for Registration Review. 

Aggregate Exposure and Risk

Given USDA’s agreement to revise existing labels to preclude exposure to livestock and 

children, an aggregate assessment is not required for Registration Review. 

Occupational Exposure and Risk

A quantitative assessment of dermal and inhalation exposure and risk to occupational handlers is 

required as starlicide application methods are likely to result in exposures to applicators. A more 

detailed review of potential post-application exposure scenarios associated with registered uses is 

needed. Based on that review, a quantitative assessment of worker re-entering treated sites may 

also be required. The occupational assessment needs to incorporate PODs selected based on 

toxicity data required for Registration Review. 

Incident Report

Based on the incident report conducted for Registration Review, there does not appear to be a 

concern at this time. The Agency will continue to monitor the incident information and if a 

concern is triggered, additional analysis will be included in the risk assessment. 

Data Requirements 
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Toxicological Data

- Acute Inhalation Toxicity (GLN 870.1300), 

- Subchronic Dermal Toxicity (GLN 870.3250) 

- Prenatal Developmental Toxicity (GLN 870.3700) 

- Reproduction and Fertility Effects (GLN 870.3800) 

- Neurotoxicity Battery (GLN 870.6200) 

- Immunotoxicity study (GLN (870.7800) 
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References 

The HED Chapter of the Reregistration Eligibility Decision Document for Starlicide, T. Myers, 

(7/13/95, TXR 0011608) 

Occupational and Residential Exposure Assessment and Recommendations for the Reregistration 

Eligibility Document for Starlicide, J. Leahy (5/3/95, D208849) 

Starlicide: Toxicology Chapter for the Reregistration Eligibility Document, I. Mauer, (4/17/95, 

D208850) 

Starlicide: Review of Human Incidents. S. Recore, (5/17/11, D389683)