# Decision Documents for

Atrazine

Com b ined PDF docum ent consis ts o f the f o llowing:

• Finalization of Atrazine IRED, and Completion of

Tolerance Reassessm ent and Reregistration Eligibility P r ocess (April 6, 2006)

• Revised Atrazine IRED (October 31, 2003)

• Atrazine IR ED (January 2003)UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON D.C., 20460

OFFICE OF
PREVENTION, PESTICIDES AND TOXIC

SUBSTANCES

MEMORANDUM

DATE: April 6, 2006

SUBJECT: Atrazine: Finalization of Interim Rer egistration Eligibility Decision and Completion of Tolerance Reassessment and Reregistration Eligibility Process

FROM: Diane Sherman, Chemical Review Manager Special Review Branch Special Review and Reregistration Division (7508 P )

Office of Pesticid e Programs

THRU: Anne Overstreet, Team Leader Special Review Branch Special Review an d Reregistration Division (7508P ) Office of Pesticide Programs

TO: Robert McNally, Branch Chief Special Review Branch Special Review and Reregistration Divis ion (7508P) Office of Pesticide Programs

CC: Deb bie Edwards , Director Special Review an d Reregistration Division (7508P ) Office of Pesticide Programs

Catherine Eiden , Branch Chief Reregistration Branch II
Health Effects Division (7509P) Office of Pesticide Programs

Robert Perlis , Assistant General Counsel

Andrea Medici , Attorney
Pesticides and Toxic Substances Law Office (2333A)

Office of General Counsel

Page 1 of 2On January 31, 2003 EPA issued an Interim Reregistration Eligibility Dec ision ( IRED ) for the

herbicide atrazine. On October 31 , 2003 EPA issued a Revised IRED for atrazine. In th ese
document s , the Agency assessed whether pesticide products containing atrazine as an active ingredient were eligible for reregistration consideri ng all relevant issues except those relating to cumulative risks associated with potential exposures to atrazine and other structurally

- related members of the chlorinated

triazine class of pesticides, including simazine, propazine, and their three chlorina ted d egradates. These pesticides share a common neuroendocrine mechanism of toxicity which results in both reproductive and

d evelopmental consequences

. Before tolerances can be considered fully reassessed or the Agency can
make a final determination of r eregistration eligibility, the Food Quality Protection Act ( FQPA ) requires the Agency to evaluate food tolerances on the basis of cumulative risk from substances sharing a common mechanism of toxicity.

The Agency recently completed its cumulative risk as sessment for the chlorinated triazine class of pesticides and has concluded that, with the mitigation measures in the 2006 simazine Reregistration Eligibility Decision and the 2003 atrazine IRED s
, the cumulative risks associated with these pesticides

are b elow the Agency’s level of concern. The cumulative risk assessment and supporting documents

are available in the public docket EPA

- HQ

- OPP

- 2005

- 0481 located on

- line in the Federal Docket Management System (FDMS) http://www.regulations.gov

. Based on that a ssessment, EPA has now concluded, after taking into account the cumulative risks associated with exposures to all of the triazines,

that all of the established tolerances for the triazine herbicides propazine, simazine, and atrazine meet the safety standar d under S ection 408(b) (2) (A) of the FFDCA , taking into account the provisions of
Sections 408(b)(2)(C) and 408(b)(2)(D)

.

In other words, the Agency has found that there is a reasonable certainty that no harm will result to the general U.S. population, inf ants, children, or o ther major identifiable subgroup s of consumers from aggregate exposure (from food, drinking water, and non

- occupational sources) to cumulative

residues of atrazine and the other chlorinated triazine pesticides

. With that finding

, and t he earlier findings contained in the 2003 IRED s f or atrazine, the Agency has now completed its task under section 4(g) of FIFRA of determining whether products containing atrazine are eligible for reregistration, and it has completed its reassessment of at razine tolerances under section 408(q) of the FFDCA. Please note that individual registrations of products containing atrazine will not be considered reregistered until they have successfully completed product

- specific reregistration.

Page 2 of 2UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

W A SHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

CERTIFIED MAIL

Dear Registrants:

This is to inform you that the Environm ental Protection Agency (hereafter referred to as EPA or the Agency) has com p leted its revised Atrazine Interim Reregistration Eligibility Decision (IRED), consistent with the Consent D ecree, as am ended, entered in Natural Resources

Defense Council v. W h itm an , Case Num b er C -99-3701 CAL, N. D. California (2002)). It does not alter the conclusions of the January 31, 2003 IRED docum ent except as described below.

There will be a 90-day public com m e nt period for this docum ent. At a later date, the Agency will publish a com p rehensive atrazine IRED incorporating changes, if any, resulting from public

com m e nt and com b ining the January and October docum ents into one docum ent.

In August 2002, the court supervising the im plem entation of the Consent Decree granted a request from EPA and Natural Resources Defense Council (NRDC) that the Decree’s deadline

for the atrazine IRED be extended. The new schedule included the com p letion of an IRED by January 31, 2003, and a revised IRED by October 31, 2003. The am ended Consent Decree states

that the revised Interim RED for atrazine m u st address the following: (1) data received by EPA prior to February 28, 2003, relating to the potential effects of atrazine on am phibian species; and (2) to the extent not addressed in the January 31, 2003 Interim RED, data, received prior to February 28, 2003, relating to the association between atrazine exposure and the incidence of prostate or other cancer in hum ans. The am ended Consent Decree also specifies that EPA is to hold FIFRA Science Advisory Panel (SAP) m eetings on these two issues.

Ecological m onitoring of watersheds was required in the January IRED due to the potential for com m unity-level and population-level risk to aquatic ecosystem s from atrazine. The January IRED states that to m itigate these ecological risks to aquatic com m unities, the Agency is requiring that atrazine registrants, in consultation with EPA, develop a program under which the registrants m onitor for atrazine concentrations and m itigate environm ental exposures

if EPA determ ines that m itigation is necessary. The program will focus on watershed im pacts of

atrazine use.

This revision to the January 31, 2003 IRED consists of three sections: 1) potential

1association between atrazine exposure and the incidence of prostate cancer and other cancers in

hum ans; 2) potential effects of atrazine on am phibian endocrinology and developm ent; and 3) ecological m onitoring and m itigation of atrazine in watersheds. In each section, this docum ent

sum m a rizes the conclusions in the January IRED pertaining to the section, developm ents since the IRED, and next steps, as appropriate. The technical docum ents supporting these revisions are listed below and appended to this IRED.

A. Review of Atrazine Cancer Epidem iology,

B. Potential Effects of Atrazine on Am phibian Gonadal Developm ent,
C. Final Reports of the Atrazine Ecological and Monitoring Subgroups,

D. Atrazine Ecological Subgroup Final Report: Recom m e ndations for aquatic

com m unity Level of Concern (LOC) and m e thod to apply LOC(s) to m onitoring data,

E. Microcosm and Mesocosm Data,

F. Atrazine Toxicity Data for CASM Sim u lations,

G. CASM Results: Steinhaus Sim ilarity Toxicity Scenario,

H. Com p arison of Annual Average CASM Steinhaus Sim ilarity for a Series of

Chem ographs Calculated with the Logistic Regression vs. Actual CASM

Sim u lations,

I. Com p arison of Sim u lated Change in Annual Production for Phytoplankton, Periphyton, Macrophytes, Zooplankton, Benthi c Invertebrates, and Fish for

CASM Param e terizations,

J. Decrease in Annual Total Production,

K. Atrazine Ecological Monitoring Pr ogram Subgroup: Recom m e ndations for Monitoring Design, and

L. Assessm ent of Potential Mitigation Measures for Atrazine, February 13, 2003.

Potential Association Betw een Atraz i ne Exposure and Prostate Cancer and Other Cancers

in Humans

January 31, 2003 IRED

The Agency’s hum an health risk assessm ent for the January 31, 2003, IRED did not include a quantitative risk assessm ent f o r cancer due to a determ ination by the EPA, consistent with conclusions reached by the SAP (June 2000), that it is unlikely that atrazine' s cancer m ode of action in the Sprague-Dawley rat is operative in hum ans. EPA’s Cancer Assessm ent Review

Com m ittee (CARC), in accordance with the 1999 Draft Guidelines for Carcinogen Risk

Assessm ent, classified atrazine as “not likely to be carcinogenic to hum ans.”

The review of the cancer epidem iology study for the January 31, 2003, IRED did, however, include epidem iological data on workers at the Syngenta St. Gabriel Louisiana plant

where atrazine is m a nufactured. The study reported a statistically significant increase in the incidence of prostate cancer am ong plant workers. The Agency, upon review of this study, requested additional inform ation on the exposure profile of the em ployees diagnosed with

2prostate cancer and this inform ation was provided and reviewed. Based on this review, it appeared that m o st of the increase in prostate cancer incidence at the St. Gabriel plant was likely due to intensive prostate specific antigen (PSA) screening of em ployees. The study was insufficiently large and had lim itations that prevent ruling out atrazine as a potential contributor

to the increase observed. On balance, however, a role for atrazine seem ed unlikely because prostate cancer was found prim arily in current em ployees who received intensive PSA screening;

there was no increase in advanced tum o rs or m o rtality; and proxim ity to atrazine m a nuf acturing did not appear to be correlated with risk.

Other cancers besides prostate were found to have an elevated, though not statistically significant, increase in risk at the St. Gabriel plant. Other studies have suggested an increased risk for ovarian, breast, and other cancers, including non-Hodgkin’s lym phom a (NHL). However, EPA had previously concluded that thes e studies were at best prelim inary and should

not serve as a basis for im plicating atrazine as a hum an carcinogen due to their m e thodological

lim itations.

July 17, 2003 SAP

To further analyze the question of exposure to atrazine and prostate cancer, an SAP

m eeting was held on July 17, 2003 (http://www.epa.gov/scipoly/sap/index.htm )

. Given the

lim ited nature of the new cancer data that stim ulated the request for a second SAP m e eting,

EPA’s subm ission to the SAP focused prim arily on the new prostate cancer data rather than the epidem iological data that the SAP in 2000 had judged inconclusive or later studies received

since 2000 that EPA found to be inconclusive. EPA asked the Panel to com m e nt on the Agency’s conclusion regarding prostate cancer and particularly the prelim inary results from a nested case-control study of the St. Gabriel m a nufacturing plant in Louisiana. In addition to this study, the SAP was provided with other epidem iological studies on atrazine exposure and prostate cancer, a review by the Agency discussing the St. Gabriel data and epidem iological data bearing on prostate cancers, com m e nts from four external peer reviewers, a Syngenta-sponsored expert panel review, and com m e nts by the Natural Resources Defense Council. As stated in the January IRED, EPA’s view of the study was that the increase in PSA screening for the St. Gabriel workers could explain the increase in prostate cancer observed in these workers and

therefore a role for atrazine seem ed unlikely. EPA acknowledged, however, that due to

lim itations in the St. Gabriel study, atrazine could not be ruled out as a potential causal factor.

The SAP’s analysis of the St. Gabriel study differed to a degree from the Agency’s

conclusion. The SAP did conclude that “the increase in Prostate Specific Antigen (PSA) screening at the St. Gabriel plant likely led to an increase in the detection of cases of prostate

cancer.” Further, the Panel noted that “[s]ubstantive and persuasive argum ents have been m a de to support the EPA’s conclusion that PSA screening could explain the observed increase in prostate cancer incidence in the workers.” Nonetheless, the Panel did not believe there was sufficient evidence to conclude that it was “unlikely” that atrazine had a role in the increased prostate cancer cases seen in the St. Gabriel study “given the severe lim itations of the St. Gabriel study, particularly those pertaining to sm all sam p le size, questionable exposure assessm ent and

3lack of an appropriate com p arison group.” According to the SAP, PSA screening m a y be only a “partial explanation” for the increase in prostate cancer seen in the St. Gabriel study and that “atrazine cannot be ruled out as a potential cause.”

The Agency agrees with the SAP’s analysis and has rewritten its conclusion as f o llows:

The increase in prostate cancer incidence at the St. Gabriel plant in Louisiana is consistent with the intensive PSA screening. This is because prostate cancer was found prim arily in active em ployees who received intensive PSA screening, there was no

increase in advanced tum o rs or m o rtality, and proxim ity to atrazine m a nufacturing did not appear to be correlated with risk. No evidence was identified, such as dose-response evidence, that perm it a determ ination that som e of the increase was likely due to exposure to atrazine although atrazine exposure cannot be ruled out at this tim e as a

cause. However, the study was insufficiently large and suffered from other lim itations that prevent a determ ination that all of the increase in prostate cancer was probably due to the intensive screening program

. Therefore, EPA concludes that the St. Gabriel study does not contribute any evidence supporting atrazine as a likely hum an carcinogen. (see Appendix A)

The SAP suggested that the Agency consider additional analysis of the St. Gabriel

cohort. However, the resulting sam p le size would still lim it the opportunity to draw further

conclusions. The Agency questions whether additional analysis is warranted for other potential risk factors (such as sm oking, diet and previ ous work history, and non-occupational or pre

em ploym ent exposure to triazine herbicides). Because of the way the study was designed, this

inform ation is not available to investigators and it m a y not be feasible to obtain such inform ation

f o r the St. Gabriel workers.

The other epidem iologic studies investigating the relationship between atrazine exposure and prostate cancer did not alter the Panel' s opinion that the evidence presented is inadequate to support the Agency' s conclusion of atrazine as an "unlikely" cause of prostate cancer seen in the St. Gabriel study. One study by Mills (1998) found a borderline statistically significant positive association between atrazine use by county with prostate cancer incidence rates in African

Am erican m a les. A second study by Alavanja et al. (2003) showed no association of selfreported atrazine exposure with prostate cancer in cohort analysis of pesticide applicators.

Epidem iological Data on Other Cancers

EPA has re-reviewed the epidem iological data regarding atrazine and cancer that were

exam ined for the SAP m eetings on atrazine in 2000 and 2003. EPA has also reviewed data that

have becom e available since the latest m eeting of the SAP in 2003. The results of those reviews

are also sum m a rized in Appendix A to this docum ent. In brief, the Agency does not find any

results am ong the available studies that would lead us to conclude that a potential cancer risk is likely from exposure to atrazine.

4Even though the epidem iological evidence and anim al data, when viewed separately, do not support a positive cancer finding for atrazine, EPA exam ined the totality of anim al and

hum an data to determ ine if that approach showed that atrazine was likely to cause a carcinogenic response in hum ans. Specifically, EPA reviewed the available anim al data to determ ine if a

m echanism could be identified which supports the biological plausibility of atrazine as a hum an carcinogen taking into account the tum o rs that were identified in the epidem iological data. This review showed that (1) lym phom as, including NHL, were generally not seen in atrazine anim al bioassays; (2) a m echanistic role for atrazine contributing to NHL has not been identified in laboratory studies; (3) tum o rs at any endocrine site other than m a m m a ry gland tum o rs in fem a le SD rats (e.g., prostate, ovarian tum o rs) have not been identified in atrazine bioassays; (4) the

SAP concluded in 2000 that the m a m m a ry gland tum o rs in rats caused by atrazine are produced

via a m echanism not relevant to hum ans; and (5) the endocrine tum o rs that have been raised in epidem iological studies (other than m a m m a ry gland tum o rs) can not be biologically tied to

atrazine’s m ode of action (i.e., decrease prolactin, decrease luteinizing horm one (LH) and suppression of ovulation). Thus, at this tim e, joint consideration of the available anim al cancer

and m ode of action data and epidem iological studi es, does not indicate that atrazine is likely to

cause cancer in hum ans.

Conclusion

In the January 31, 2003 IRED, EPA concluded that, considering the anim al data and the

hum an epidem iological data, atrazine is “not likely to be carcinogenic in hum ans”. That conclusion allowed EPA to find that there is a reasonable certainty of no harm from exposure to
atrazine so far as cancer risk is concerned. Results in the St. Gabriel study and other recent epidem iological studies regarding atrazine’s potential link to cancer do not alter that conclusion. Further, any weight attributable to these data is weakened by the data in anim als that f a il to reveal any m echanism of action for atrazine consistent with the cancers observed in the studies. Accordingly, EPA concludes that atrazine is not likely to be a hum an carcinogen."

Next Steps

Since the July 2003 SAP m eeting, EPA has received two new pieces of inform ation: (1) a report f r om the National Cancer Institute (NCI) re-analyzing previous epidem iologic studies of atrazine and non-Hodgkin = s lym phom a using hierarchical techniques to adjust for the effects of

m

u ltiple exposures; and (2) a nested case-control study conducted for Syngenta of workers at the St. Gabriel plant using m o re detailed job histor ies to evaluate exposure indices. The Agency plans to conduct a com p rehensive review of both studies. EPA’s prelim inary view of these studies is discussed in Appendix A. EPA is al so expecting to receive additional epidem iological studies and analyses concerning atrazine and cancer from the NCI’s Agricultural Health Study in the next one to two years. These studies and analyses include the following: an update of the Agricultural Health Study on prostate cancer capturing additional prostate cancer cases; an analysis of all the non-Hodgkin’s lym phom a cases reported in the Agricultural Health Study; and a special analysis of all cancers related to atrazine exposure in the sam e Agricultural Health Study cohort. The latest projection is that the NCI will com p lete these studies and analyses in

5m i d-2005.

Af ter all of the inf o rm ation has been subm itted and reviewed, the Agency plans to

convene another SAP m eeting concerning atrazine and its possible association with carcinogenic

effects. At that m eeting, EPA intends to present the SAP with all of the data bearing on atrazine and cancer, including the old and new epidem iology studies. In the m eantim e, EPA will

continue its review of all new data subm issions. If at any tim e, results from any of the new data

subm issions raise significant questions that would benefit substantially from SAP review prior to

subm ission of all of the data, the Agency will hold a SAP m eeting bef o re all aspects of the Agricultural Health Study are com p leted.

EPA intends to thoroughly review any SAP report from any future m e eting, once issued,

and to revise its determ inations regarding the cancer potential of atrazine, as necessary. Any revisions will be included in either a revision to the October 31, 2003 IRED or the final reregistration decision for atrazine depending on the tim ing of the future SAP m eeting relative to issuance of the final atrazine reregistration decision.

Potential Effects of Atraz i ne on Am phibian Endocrinology and Development

January 31, 2003 IRED

In the ecological risk assessm ent for the January 31, 2003 IRED, the Agency did not suggest that endocrine disruption, or potentia l effects on endocrine-m ediated pathways, was regarded as a regulatory endpoint for ecological effects. Nor did the Agency have reliable

evidence at that tim e to state that atrazine caused endocrine effects in the environm ent. The IRED stated that based on the existing uncertainties in the available database, atrazine should be subject to m o re def i nitive testing once the appropriate testing protocols have been established. The Agency was aware that several pertinent studies were being perform e d by researchers that

m a y reduce som e of the uncertainties in understanding potential atrazine effects on am phibian endocrinology and reproductive and developm ental responses.

June 17-20, 2003 SAP

Since the January IRED, the Agency has conducted a com p rehensive evaluation of the available data regarding the potential effects of atrazine on am phibian gonadal developm ent and presented its assessm ent for external peer review to a SAP in June 2003. In a May 29, 2003 white paper, the Agency sum m a rized seventeen studies consisting of both open literature and registrant-subm itted laboratory and field studies involving both native and non-native species of frogs (see Appendix B). In its white paper the Agency concluded that none of the studies fully

accounted for environm ental and anim al husbandry factors capable of influencing endpoints that

the studies were attem p ting to m easure. The Agency also concluded that the current lines-of

evidence did not show that atrazine produced consistent effects across a range of exposure

concentrations and am phibian species tested.

6Based upon this assessm ent, the Agency concluded and the SAP agreed that there is

sufficient evidence to form ulate a hypothesis that atrazine exposure m a y im pact gonadal developm ent in am phibians, but there are currently insufficient data to confirm or refute the hypothesis (http://www.epa.gov/oscpm ont/sap/2003/J une/junem eetingreport.pdf). Because of the inconsistency and lack of reproducibility across studies and an absence of a dose-response relationship in the currently available data, the Agency has determ ined that it does not change the conclusions reached in the January 31, 2003 IRED regarding atrazine’s effects on

am phibians.

Next Steps

Based on the conclusions from the Agency’s white paper and recom m e ndations of the SAP, the Agency will seek additional data to reduce uncertainty regarding the potential risk to

am phibians (http://www.epa.gov/oscpm ont/sap/2003/june/dataevaluationreports.htm )

. This data

collection will f o llow the m u lti-tiered process outlined in the Agency’s white paper. This approach to collecting additional inform ation through further studies, which was endorsed by the SAP, can be used to address uncertainties associated with the potential causal relationships between atrazine exposure and gonadal developm ent and characterize the nature of any concentration-response relationship.

Ecological Monitoring and Mitigation of Atraz i ne in Watersheds

January 31, 2003 IRED

The ecological risk assessm ent for the January IRED stated that the Agency has ecological risk concerns from the use of atrazine and identified the potential for com m unity-level and population-level risk to aquatic ecosystem s at prolonged concentrations of atrazine from 10 to 20 ppb. To m itigate these ecological risks to aquatic com m unities and to determ ine that atrazine is eligible for reregistration, the Agency required that atrazine registrants, in consultation with EPA, develop a program under which the registrants m onitor for atrazine

concentrations and m itigate environm ental exposures if EPA determ ined that m itigation is

necessary. This program would focus on watershed im pacts of atrazine use.

The January IRED f u rther stated that the program will include an appropriate ecological level of concern (LOC), identified by EPA; deve lopm ent of a protocol for a m onitoring program that specifies the frequency, location, and tim ing of sam p ling, as well as an appropriate

coordination with Total Maxim u m Daily Load (TMDL) program s; triggers f o r m itigation

m easures; and description of m itigation m easures that will be taken if triggers are exceeded.

This m onitoring and m itigation program would be designed, conducted and im plem ented on a

tiered watershed level and m u st be consistent with existing state and f e deral water quality

program s.

Follow-up to January 31, 2003 IRED

7The following description highlights how EPA developed the specifics of the ecological

m onitoring and m itigation program consistent with the January 2003 IRED. The Office of Pesticide Program s, the Office of Research and Developm ent, and the Office of W a ter collaborated to integrate and develop this program

.

Level of Concern (LOC)

The sensitive endpoint in the ecological assessm ent for atrazine is a change in the structure and function of prim ary producers in the aquatic com m unity. Concentrations of atrazine that affect plant productivity and com m unity structure typically occur at levels lower than those that directly intoxicate fish and aqua tic invertebrates. By focusing on aquatic plant

com m unity structural changes, the m o st sensitive endpoint, the Agency intends to protect fish

and invertebrates from the direct effects of atrazi ne as well as the effects that atrazine could have on the habitat and food sources of aquatic anim als (see Appendices C- K).

The Level of Concern (LOC) was derived to ensure that the atrazine concentrations in watersheds will not cause signif i cant changes in aquatic plant com m unity structure. The LOC is based on an analysis of 25 m i crocosm and m e socosm studies cited in the Final Report of a report provided in Appendix D. To establish the LOC, it was necessary to quantify the results of the

m e socosm and m i crocosm studies by rating their reported results based on the significance of the effects on aquatic plant productivity and com m unity structure. Each study was analyzed to establish the reported effect(s) and the atrazine exposure profile, which reflects the m a gnitude, frequency and duration of atrazine concentrations in the study. This analysis revealed a wide range of study designs and quality and also indicat ed that a wide range of atrazine exposure profiles could result in significant change in aquatic com m unity productivity and structure. A

m e thod was developed to separate the reported results on plant com m unity productivity and

structure observed in these studies into those that were significant versus those with slight to noeffects.

Since atrazine exposure profiles in natural system s, in this case stream s, will typically be

com p lex, it was necessary to develop a m e thod to analyze m onitoring data to determ ine when

m onitored exposure profiles are functionally-equivalent to those profiles observed in m e socosm and m i crocosm studies showing significant changes when the m onitored profiles are functionally-equivalent to those studies that showed no significant effects.

Using a range of atrazine exposure profiles re presentative of those that caused significant

effects in the m i crocosm and m e socosm studies, as well as those that did not result in significant effects, an ecological food chain m odel that predicts changes in aquatic com m unities in stream s (in this case, C om prehensive A quatic S ystem s M odel, CASM), was used to develop the m eans of interpreting whether or not any atrazine exposure profile observed in the m onitoring study would likely be associated with a signif i cant ef f ect on aquatic com m unities. These analyses

determ ined that a com m unity sim ilarity index (CSI) that quantif ies the average changes in

biom ass for plant species of the m odeled aquatic com m unity, is the m o st useful m odel param e ter to segregate those m e socosm and m i crocosm studies that exhibited significant effects from those

8that did not. Conceptually, this index is cons istent with the observed effects of atrazine on prim ary producers in aquatic ecosystem s. More specifically, through this analysis it was

determ ined that an average CSI change of 5% or greater over the course of a study reasonably

discrim i nated m i cro- and m e socosm exposure prof iles associated with significant effects (i.e., irreparable changes to ecosystem s) from t hose that did not show significant effects.

Consequently, these analyses establish the LOC as any m easured atrazine exposure profile obtained through a m onitoring study that would result in a predicted 5% or greater average change in the CSI through the use of CASM. Additional analyses over the duration of the three year m onitoring study will evaluate the use of additional aquatic com m unity m odels (e.g., Aquatox), and com p arable m odeled indices, to provide additional m odel options for States, Tribes or other parties to evaluate data that m a y be collected in other m onitoring program s.

Monitoring Program Protocol

The m onitoring protocol is initially focused on flowing water bodies (i.e., stream s) associated with corn and sorghum production (see Appendix K). Future efforts (see below) will

address the need to m onitor estuaries and water bodies associated with sugarcane production. In addition, results of raw water m onitoring from the on-going atrazine m onitoring program for drinking water, as described in the January 31, 2003 IRED, will be analyzed to determ ine its potential utility in evaluating potential ecological effects in static water bodies.

The purpose of the m onitoring program in flowing waters is to estim ate the m a gnitude and extent to which water bodies with the greatest potential vulnerability to atrazine exposure (prim a rily based on atrazine use and runoff potential) are exceeding the level of concern consistent with the atrazine ecological risk assessm ent, which was described above. The initial analyses identified three tiers of watersheds relevant to atrazine use in corn and sorghum

. The first tier of approxim a tely 10,000 watersheds had som e level of atrazine use on corn and sorghum

. The watersheds identified in this assessm ent were prim arily at the 5 th , or Hydrologic Unit Code (HUC)-10/11, level of a hierarchal system of m a pping watersheds established by the United States Geological Survey (USGS). At this level, watersheds are typically 40,000 to 250,000 acres in size. From this first tier, a second tier of 5,860 HUC-10/11 watersheds was identified based on use intensities of 0.25 lb active ingredient (ai)/county acre or higher. From this second tier of watersheds, a third tier of 1,172 watersheds was identified based on their predicted potential to be am ong the m o st vulnerable to atrazine surface water loading from use on corn and sorghum

. Through the developm ent of a statistically-based survey design, EPA then selected 40 HUC-10/11 watersheds which will give a statistical representation of the third tier of 1,172 such watersheds predicted to be m o st potentially vulnerable. These 40 m onitored watersheds are located in 10 states: Ohio, Indian a, Kentucky, Illinois, Iowa, Missouri, Nebraska, Minnesota, Tennessee, and Louisiana. The selected watersheds averaged 129 square m iles in size, with a m e dian size of 121 square m iles. Monitoring sites (index sites) will be located in flowing water bodies within the 40 watersheds. Two years of m onitoring results from these sites

will be com p ared to the LOC values. The registrant shall collect m onitoring sam p les every 4 days prior to, during, and following the growing s eason. In addition, the registrant is required to

9m onitor 10 watershed sites daily f o llowing f l ow events to better estim ate tem poral variability f o r the data collected in the rem a ining 30 watersheds. Based on the results from the two-year

m onitoring study in each watershed, as interpreted by the LOC, the Agency will evaluate the

need f o r m o re m onitoring and/or m itigation actions in the 40 HUC-10/11 watersheds and the

im plications, if any, for the larger set of 1,172 m o st potentially vulnerable watersheds.

Future Monitoring Decisions for Other W a ter Bodies

Estuaries will not be m onitored in 2004. Discussions will be conducted with the Oceans

and Coastal Protection Division in the Office of W e tlands, Oceans, and W a tersheds (OW O W ) to
review all relevant data to determ ine whether and to what extent m onitoring for levels of atrazine

should be undertaken for estuaries. The role of dilution and transport in estuaries m u st be

determ ined. It m a y be possible to gather som e inform ation on these param e ters by looking at

nitrate concentrations or other chem ical as a m a rker to ascertain how to approach an estuary

m onitoring program . This analysis will be com p leted by March 2004. If it is determ ined a

m onitoring study is required, it is recognized additional efforts will be necessary to develop a

m onitoring program

.

To evaluate the potential for ecological concerns in static water bodies (i.e., lakes and reservoirs), raw water data on atrazine concen trations collected from the approxim a tely 140

Com m unity W a ter System s that are being m onitored f o r hum an health concerns will initially be

used. In addition, the registrant will provide historical data from the Voluntary Monitoring Program (VMP) sites. The m e thods used to determ ine the LOC for flowing water bodies are

am enable for use in static water bodies. The EPA m u st determ ine on a statistical and ecosystem

basis to what extent the m onitoring data from the drinking water m onitoring program should be interpreted for a given water body and how statistical inferences from the results of this set of

static water bodies can be m a de to a larger population of potentially vulnerable static water

bodies. This inform ation will provide the basis for developing a m onitoring strategy for static

water bodies.

A strategy will be developed to select the m o st appropriate locations and num ber of sites

for m onitoring atrazine in sugarcane growing areas. The sugarcane use area is a unique situation

which has clear freshwater and estuarine issues. As a pilot, the registrant has offered to m onitor

f our additional sites distributed between Louisiana and Florida with one being the Iberville

Com m unity W a ter System already designated for increased m onitoring in the drinking water

program

. The selection of these pilot sites for evaluating potential ecological effects and the protocol for m onitoring will be com p leted by March 2004.

Triggers f o r Mitigation Measures in Flowing W a ter Bodies

For the 40 watersheds, the registrant shall m onitor an index site within the watershed for two years, regardless if a decision to initiate rem e diation occurs in the f i rst year. If m onitoring within a watershed indicates exceedences of the 5% average CSI threshold, based on CASM

m odel results, in each of the two years, the registrant will initiate and conduct a TMDL or

10com p arable watershed m a nagem e nt program within the particular watershed where the exceedence occurred, consistent with the state’s ongoing TMDL or watershed program

. If a

TMDL or com p arable watershed m a nagem e nt program is already in place by USDA, state, or other entity in a given watershed, the registrant will then work with these existing program s to
address the atrazine exceedence. If an exceedence occurred in the first year of sam p ling within a watershed, the registrant will, at a m i nim u m initiate stewardship outreach, preferably through an existing USDA or state-sponsored watershed m a nagem e nt program if one exists.

If an index site in a watershed has exceeded the sim ilarity threshold over a two year period, the registrant shall initiate and conduct a TMDL (or sim ilar) program to reduce atrazine

concentrations associated with the stream reach at the index site by additional m onitoring and

m a naging atrazine uses in those portions of the watershed that feed into the index site and result

in the exceedences. At the sam e tim e, the registrant shall conduct additional m onitoring at other sites in the watershed suspected to be sim ilar to the index site in order to determ ine if other water

bodies in the watershed also exceed the 5% sim ilarity threshold. If these areas are determ ined to

exceed the sim ilarity threshold, then the registrant shall initiate and conduct TMDL (or sim ilar)

m itigation in those areas.

The registrant m u st also initiate and conduct rem e diation im m e diately in any watershed

which shows an exceedence of 

### $ 15% of the CSI rather than wait for a second year of data.
However, m onitoring will still continue at the original index site in the second year.

If m onitoring results indicate an exceedence in one of the two years for a given index site within a watershed, a decision regarding additional m onitoring or other watershed m a nagem e nt activities will be based on the specific data for the location and the results of the overall study.

The data derived f r om all of the 40 watersheds will provide inf o rm ation needed to better quantif y and interpret sam p ling variability in the context of the exceedence threshold. These future analyses will inf o rm decision criteria f o r those cases where variability in m onitoring data overlaps uncertainties in the LOC derivation.

For an index site within a watershed, if m onitoring results indicate no exceedences of the 5% average sim ilarity threshold index based on CASM m odel results in each of the two years,

then no f u rther action will be required in the watershed.

For all of the data collected in the 40 watersheds, interpretation of m onitoring data after two years would include an assessm ent as to whether or not unusual m e terological conditions (e.g., high or low rainfall) existed during the m onitoring period. This could require a third year

of sam p ling to m a ke an inform ed decision on a watershed' s condition.

In addition, if States or Tribes use the sam e or com p arable LOC and m onitoring protocols (e.g., com p arable sam p ling frequencies and analy tical techniques) at a selected stream reach outside of the 40 watersheds, as described in the ecological and atrazine m onitoring subgroup reports (Appendix C-J), as well as, em ploy decision criteria com p arable to those described above, the registrant will initiate and conduct a TMDL or com p arable watershed m a nagem e nt

11program within that watershed if the State or Tribal data shows an exceedence of the LOC for two years, consistent with the state’s ongoing TMDL or watershed program

.

After the Agency receives the data from the 40 watersheds, it will be analyzed to interpret the status of the 1,172 Tier 2 watersheds. Due to the nature of this m onitoring design it will be possible to m a ke statistical inf e rences with the data collected f r om the 40 watersheds as

to the m a gnitude and extent to which LOC exceedences could be occurring in the rem a ining tier of 1,172 watersheds considered to be the m o st potentially vulnerable. After these statistical

inferences are com p leted, a decision about m onitoring in the rem a ining 1,172 vulnerable

watersheds will be m a de, with the understanding it is possible that further m onitoring and/or

m itigation m a y be required of the registrant in these other watersheds.

Description of Mitigation Measures

The specific techniques to be em ployed by the registrant to reduce atrazine loads in a watershed that has atrazine concentrations that exceed the LOC will be watershed specific and undertaken in partnership with any existing watershed m a nagem e nt program s. The registrant

will f o llow steps that are typically em ployed in the Clean W a ter Act TMDL program or sim ilar

m a nagem e nt program s as follows:

1. Problem Identification - Identify pollutant causing im pairm e nt and im paired water body and determ ine the pollutant reductions needed to achieve water quality standards (note that in this specific situation exceedence of the atrazine LOC will have already established an

im pairm e nt and a cause, with the understanding that for a given water body additional pollutants could also be contributing to biological im pairm e nt).

2. Current Situation and Desired Objective -

Indicate desired outcom e of TMDL process.

3. Source Assessm ent - Identify pollution source and contribution to im pairm e nt.

4. Allocation of loads

- Allocate the pollutant loadings am ong the various pollutant sources.

5. Im plem entation

- Describe actions to m itigate the sources of pollution (e.g., best m a nagem e nt practices).

6. Follow-up Monitoring -

Determ ine ef f ectiveness of im plem ented m itigation m easures.

7. Feedback Mechanism

-

12Review of m itigation m easures during im plem entation period to determ ine if adjustm e nts are needed.

The Clean W a ter Act requires that States identif y waters that f a il to attain water quality

standards and establish TMDLs at levels that attain or m a intain their water quality standards. EPA is required to review and approve or disapprove the list of im paired waters and TMDLs. If EPA disapproves the State’s list or the TMDL, EPA is required to identif y the im paired waters

or establish TMDLs. The States and EPA establish TMDLs in a particular watershed by

determ ining pollutant loads that will allow the attainm e nt of water quality standards, analyzing existing pollutant loads and sources, and specifying the pollutant load reductions necessary to attain water quality standards. TMDLs are im plem ented through existing Federal, State or local requirem e nts and program s. EPA encourages TMDLs that are established and im plem ented as part of an overall watershed strategy f o r im proving water quality.

The Agency expects that the TMDL process (or sim ilar watershed m a nagem e nt program )

will result in m itigation m easures that, when im plem ented, will ef f ectively lower the level of

atrazine to below the level of concern. These m itigation m easures could include: buf f e r zones, different application or incorporation m e thods, restrictions on the tim ing of application due to rain, and lower application rates. Im plem entation of these controls also will include

confirm a tory follow up m onitoring to insure that the atrazine levels are below the LOC. Given the rapid progress the States have m a de by incorporating TMDL approaches in watershed

m a nagem e nt program s, EPA is confident that m a nagem e nt activities undertaken by the registrant

consistent with m eeting the loading reductions identified in a TMDL are expected to be successful in reducing loadings of atrazine. Since 1996, m o re than 9000 TMDLs have been established and approved, leading to activities that have im proved water quality. Pollutant loadings have been reduced and water quality im proved as reported by the Of f i ce of W a ter' s Office of W e tlands, Oceans and W a tersheds (see http://www.epa.gov/owow/tm dl/). In the unlikely event that im plem entation of loading reductions identif ied in TMDLs is not ef f e ctive, the Agency reserves the right to take further action under FIFRA to m itigate this risk from atrazine and will consider, as appropriate, the benef its of atrazine use in the particular watershed.

Benefits of Atraz i ne Use

The total or national econom ic im pact resulting from the loss of atrazine to control grass and broadleafed weeds in corn, sorghum and sugarcane would be in excess of 2.0 billion dollars per year if atrazine were unavailable to growers (Appendix L, “Assessm ent of Potential Mitigation Measures for Atrazine”, February 13, 2003).

A watershed-specific analysis has not been factored into this assessm ent because of the uncertainty surrounding potentially im pacted watersheds and any required m itigation. However,

econom ic im pacts could be expected to parallel those for drinking water as described below.

Specifically, EPA analyzed what would be the im pact to the corn industry in areas in

13watersheds contributing to Com m unity W a ter System s which find atrazine concentrations exceeding the Agency' s level of concern, and f ound that growers would incur an average loss of 9 bushels per acre (nationwide corn yield averaged 138 bushels per acre in 2001), as well as an increased cost for a replacem ent herbicide. This yield loss plus increased herbicide cost m a y result in an average estim ated loss of $28 per acre. This translates to a yearly loss of 1.6 billion dollars of lost revenue annually nationwide.

Likewise, the im pact to the sugarcane industry would also be substantial. If growers in the watersheds contributing to the Com m unity W a ter System s which find atrazine concentrations exceeding the Agency' s level of concern, no longer had atrazine available to them , a 10 to 40 percent crop loss would be incurred along with an increase in alternative herbicide cost. This translates to a yearly loss of $89.5 m illion but could be as m u ch as $343.6 m illion if a 40 percent

loss were realized.

Finally, if atrazine were elim inated from the m a rket, the m o st likely chem ical broadleaf weed control options would be post-em ergence applied herbicides (dicam ba, 2,4-D, brom oxynil, and prosulfuron). Post-em e rgence application of herbicides carries certain risks. These include: 1) greater com p etition of the weeds with the crop early in the season as weed control is delayed into the growing season; 2) crop injury from herbicides applied directly to the em erged crop and weeds; and 3) if the opportunity to apply the herbicide is m i ssed due to weather or som e other factor, there are fewer or no em ergency rem e dies for weed control. Thus, there are non

m onetary costs that would be associated with the loss of atrazine as well as the substantial

f i nancial im pacts.

Determination of Interim Reregistration Eligibility

The Agency has determ ined that atrazine products are eligible for reregistration provided that: (i) the circum stances described in this docum ent (including im plem entation of any ecological risk m itigation m easures identified through the m onitoring program ) are realized; (ii) any current data gaps and additional data needs are addressed; and, (iii) the consideration of the

cum u lative risk for the triazines supports a final reregistration eligibility decision. Further we have concluded that during the period of data collection and risk m itigation m e asures called f o r in this docum ent, the benef its of continued use of atrazine will outweigh any potential ecological

risk.

Although the Agency has not considered the cum u lative risk for all the triazines, the Agency is issuing this am endm ent to the interim reregistration eligibility decision now in order to identify risk reduction m easures that are necessary to support the continued use of atrazine. Based on the current evaluation of atrazine, the Agency has determ ined that atrazine products,

unless used in accordance with the conditions of this docum ent, would present risks inconsistent

with FIFRA. Accordingly, should a registrant fail to im plem ent any of the risk m itigation

m easures identified in this docum ent, the Agency m a y take further regulatory action to address

the risk concerns from the use of atrazine products.

14Because the Agency has not yet considered cum u lative risk for all of the triazines, this reregistration eligibility decision does not f u lly satisf y the reassessm ent of the existing atrazine food residue tolerances as called for by the Food Quality Protection Act (FQPA). W h en the Agency has com p leted the cum u lative assessm ent, atrazine tolerances will be reassessed in that light. At that tim e, the Agency will reassess atrazine along with the other triazine pesticides to

com p lete the FQPA requirem e nts and m a ke a final reregistration eligibility determ ination. By publishing this interim decision on reregistration eligibility and requesting m itigation m easures now for the individual chem ical atrazine, th e Agency is not deferring or postponing FQPA requirem e nts; rather, EPA is taking steps to assure that uses which exceed FIFRA’s unreasonable

risk standard do not rem a in on the label indefinitely, pending com p letion of assessm ent required under the FQPA. This decision does not preclude the Agency from m a king further FQPA

determ inations or tolerance-related rulem a kings that m a y be required on this pesticide or any

other in the future.

What Registrants Need to Do

In order to be eligible for reregistration, registrants need to im plem ent the risk m itigation

m easures outlined above, which include, am ong other things, developm ent and subm ission of the

f o llowing:

Potential Effects of Atrazine on Am phibian Endocrinology and Developm ent

Phase I: Response of larval Xenopus laevis to estradiol: assessm ent of developm ent and gonadal m o rphology. Response of larval Xenopus laevis to atrazine: assessm ent of developm ent and gonadal m o rphology.

Phase II:* R esponse of larval Xenopus laevis to atrazine: assessm ent of gonadal and plasm a sex steroid concentrations.

Phase III:* R esponse of larval Xenopus laevis to atrazine: assessm ent of gonadal

arom atase activity.

Phase IV:* Response of larval Xenopus laevis to atrazine and an arom atase inhibitor:

assessm ent of developm ent, gonadal m o rphology, sex steroid

concentrations and arom atase activity.

Phase V:* R esponse of Rana pipiens to atrazine: assessm ent of reproductive fitness.

* Conducting the studies in phases II through V are conditional on the results from the previous phase indicating an effect. For exam ple, if m o rphological abnorm a lities are observed in the gonads of larval Xenopus laevis after exposure to atrazine (Phase I) then the Phase II studies on gonadal and plasm a sex steroid concentrations would be conducted. However, if the Phase I studies show negative results then the registrant does not need to proceed with the subsequent

15study. EPA requests to review all of the protocols before the studies are initiated.

Ecological Monitoring and Mitigation of Atrazine in W a tersheds

Atrazine Monitoring For Potential Ecological Ef f ects on Aquatic Com m unities: Part 1. Flowing W a ter Bodies in Corn and Sorghum Use Areas.

Atrazine Monitoring For Potential Ecological Ef f ects on Aquatic Com m unities: Part 2.

W a ter Bodies in Sugarcane Use Areas.

Atrazine Monitoring For Potential Ecological Ef f ects on Aquatic Com m unities: Part 3.

Static W a ter Bodies.

Atrazine Monitoring For Potential Ecological Ef f ects on Aquatic Com m unities: Part 4.

Estuarine W a ter Bodies.

Data Call-In data f o r the ecological m onitoring of watersheds will be sent to Of f i ce of Pesticide Program s (OPP) and Office of W a ter (OW ) , as well as the State or Tribe where the

data are collected. Once the m onitoring data has been quality controlled it will be posted in

OW ’s publically available STORET database.

If you have questions on this docum ent, please contact the Chem ical Review Manager, Eric R. Olson at (703) 308-8067.

Sincerely,

Betty Shackleford, Acting Director Special Review and Reregistration Division

12 Attachm e nts

16UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES AND

TOXIC SUBSTANCES

OFFICE OF PESTICIDE PROGRAMS

SPECIAL REVIEW and REREGISTRATION

DIVISION
(7508C)

Debra Edwards, Ph.D., Director

Correction to the Existing Stocks Section in the January 2003 Atrazine IRED

The October 1, 2003 deadline for distribution of product by persons other than the registrant in Existing Stocks provision in Chapter V, Section C of the January 2003 Atrazine IRED is incorrect. The new Existing Stocks policy for products containing atrazine is as follows:

The Agency has determined atrazine products (other than product containing 4% or less atrazine active ingredient) bearing old labels/labeling cannot be sold to end users after January 1, 2005 unless these products have a sticker label attached which refers to supplemental labeling. The supplemental label must also be given out when it is sold to an end user. The products containing 4% or less atrazine active ingredient are not required to follow the January 1, 2005 date for sticker labels or supplemental

labels. However, any product with less than 4% active ingredient that is manufactured six months after receiving new EPA approved label must bear the revised labeling. The residential turf products; 829­ 268, 7401-318, 9404-72, 11715-347, and 51036-363 are also exempt from this January 1, 2005 requirement. However, any of these products that are manufactured after January 1, 2005 must bear the revised labeling.UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

W A SHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

MEMORANDUM

SUBJECT: Errata/Addendum Sheet for Changes to the Atrazine Interim Reregistration Eligibility Decision.

FROM: Anne Overstreet Special Review Branch Special Review and Reregistration Divsion

TO: Public Docket for Atrazine

Listed below are changes/clarifications a dded to the Atrazine Interim Reregistration Eligibility Decision (IRED) which was published in January, 2003. The regulatory decision of the IRED did not change as a result of these clarifications.

1) The occupational and non-occupational m itigation areas were updated to reflect m o re recent
data. Because the Agency recently updated several scenarios using ORTEF data, a respirator is no longer necessary for backpack sprayers. 2) Appendices A-H were added to the IRED. They are as follows:

- Appendix A: Atrazine Use Patterns Eligible for Reregistration

- Appendix B: Studies Used to Support the Reregistration of Atrazine

- Appendix C: Technical Support Docum e nts

- Appendix D: Citations Considered to Be Part of the Database Supporting the Interim Reregistration Decision (Bibliography)

- Appendix E: Generic Data Call-In

- Appendix F: Product Specific Data Call-In

- Appendix G: EPA’s Batching of Atrazine Products for Meeting Acute Toxicity Data Requirem e nts For Reregistration

- Appendix H: Atrazine Monitored W a tersheds

Appendix B was previously posted on the web. It has been subsequently been am ended to accurately reflect the data gaps and studies used in support of reregistration. 3) The Label Table in Section IV has been added to the IRED. In order to be eligible for

1reregistration, all product labels are to be am ended to incorporate the risk m itigation m easures outlined in Section IV. Table 29 has been added to the IRED and describes how language on the

labels should be am ended 4) Clarification was m a de relating to the atr azine cancer assessm ent language. The findings of

the 2000 SAP m eeting were included. 5) Corrections were m a de pertaining to the baseline attire f o r occupational scenarios. Baseline clothing typically includes: long-sleeved shirt and long pants, shoes and socks. For scenario 5 (Table 14 of the IRED), application of liquids via groundboom , baseline assessm ents also included gloves. This clarification was m a de in both the text and footnotes of Table 14.6) In Table 15, for scenarios 10&11 (application of liquids via backpack sprayer and lowpressure handwand), the num ber of acres treated changed from 1 to 5 based on further

refinem e nts to input param e ters. 7) In Table 15 for the following scenarios: -12(a) - application of liquid via handgun and com p ressed air sprayer

- 12(b) - W DG via lawn handgun

- 12(c) - W SP via lawn handgun -13 - application of granular via push-type spreader

- 7 - application of liquids via handgun

A f ootnote was added which specif i ed that these scenarios considered baseline attire plus gloves.

8) There has been harm onization between Sections IV and V with the MOA. 9) The Atrazine W a ter Managem e nt Inform ation Center (AW M IC) has been changed to the

Atrazine W a ter Inform ation Center (AW I C). It has been changed in Chapters four and five of

the IRED.

2UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

W A SHINGTON, D.C. 20460

OFFICE OF PREVENTION, PESTICIDES

AND TOXIC SUBSTANCES

CERTIFIED MAIL

Dear Registrants:

This is to inform you that the Environm ental Protection Agency (hereafter referred to as EPA or the Agency) has com p leted its review of the available data and public com m e nts received related to the prelim inary and revised risk assessm ents for the pesticide atrazine. The public com m e nt period on the revised risk assessm ent phase of the reregistration process is

closed. Based on com m e nts received during the public com m e nt period and additional data

received from the registrants, the Agency revised the hum an health and environm ental effects

risk assessm ents and m a de them available to the public on May 6, 2002. Additionally, the Agency held a Technical Briefing on April 16, 2002, where the results of the revised hum an health and environm ental effects risk assessm ents were presented to the general public. This Technical Briefing concluded Phase 4 of the Public Participation Pilot Process developed by the

Tolerance Reassessm ent Advisory Com m ittee (TRAC), and initiated Phase 5 of that process. During Phase 5, all interested parties were invited to participate and provide com m e nts and suggestions on ways the Agency m i ght m itigate the estim ated risks presented in the revised risk

assessm ents. This public participation and com m e nt period com m e nced on May 6, 2002, and closed on July 5, 2002.

Based on its review, EPA has identif ied risk m itigation m easures that the Agency believes are necessary to address the hum an health and environm ental risks associated with the

current use of atrazine. The EPA is now publishing its interim decision on the reregistration eligibility of and risk m a nagem e nt decision f o r the current uses of atrazine and associated hum an health and environm ental risks. The reregistration eligibility and tolerance reassessm ent
decisions f o r atrazine will be f i nalized once the cum u lative assessm ent f o r all of the triazine

herbicides is com p lete. The enclosed “Interim Reregistration Eligibility Decision f o r Atrazine” was approved on January 31, 2003, and contains the Agency’s decision on the individual

chem ical atrazine.

The Agency is aware that several pertinent studies are being perform e d at this tim e by

3researchers that m a y reduce som e of the uncertainties in understanding potential atrazine effects

on am phibian endocrinology and reproductive and developm ental responses. The Agency has

com m itted to provide these studies along with other available studies, a sum m a ry of the

available data and m e thodologies and various data analyses for an external scientific review by the Federal Insecticide, Fungicide and Rodentic ide Act (FIFRA) Science Advisory Panel (SAP) at a public m eeting which is scheduled for June, 2003. The Agency anticipates that the results

from this SAP m eeting will provide significant input to enable it publish an am endm ent to this

IRED in October 2003 which will address the i ssue of the potential effects of atrazine on

am phibian endocrinology and developm ent.

A Notice of Availability f o r this Interim Reregistration Eligibility Decision (interim RED) is being published in the Federal Register

. To obtain a copy of the interim RED

docum ent, please contact the OPP Public Regul atory Docket (7502C), US EPA, Ariel Rios Building, 1200 Pennsylvania Avenue NW

, W a shington, DC 20460, telephone (703) 305-5805. Electronic copies of the interim RED and all supporting docum ents are available on the Internet. See http:www.epa.gov/pesticides.

The interim RED is based on the updated technical inform ation found in the atrazine public docket. The docket includes background inform ation and com m e nts on the Agency’s prelim inary risk assessm ents, the Agency’s April 2002 revised risk assessm ents for atrazine, and

a docum ent sum m a rizing the Agency’s Response to Com m e nts. The Response to Com m e nts
docum ent addresses corrections to the prelim inary risk assessm ents subm itted by chem ical registrants and responds to com m e nts subm itted by the general public and stakeholders during

the com m e nt period on the risk assessm ent. The docket also includes com m e nts on the revised

risk assessm ent, and any risk m itigation proposals subm itted during Phase 5. For atrazine, a proposal was subm itted by Syngenta Crop Protecti on, Inc. (Syngenta), a technical registrant.

Com m e nts on m itigation or m itigation suggestions were subm itted by growers, agricultural extension agents, environm ental organizations, university scientists, and various other organizations.

This docum ent and the process used to develop it are the result of a pilot process to facilitate greater public involvem e nt and participation in the reregistration and/or tolerance

reassessm ent decisions for pesticides. As part of the Agency’s effort to involve the public in the

im plem entation of the Food Quality Protection Act of 1996 (FQPA)
, the Agency is undertaking a special effort to m a intain open public dockets on pesticides and to engage the public in the reregistration and tolerance reassessm ent processes for these chem icals. This open process follows the guidance developed by TRAC, a large m u lti-stakeholder advisory body that advised the Agency on im plem enting the new provisions of the FQPA. The reregistration and tolerance

reassessm ent reviews for atrazine are following this new process.

Please note that the atrazine risk assessm ent and the attached interim RED concern only this particular triazine. This interim RED presents the Agency’s conclusions on the dietary and

4residential risks posed by exposure to atrazine alone. The Agency has also concluded its

assessm ent of the ecological risk, with the exception of the potential atrazine effects on

am phibian endocrinology and reproductive and developm ental responses, and worker risks

associated with the use of atrazine. Because th e FQPA directs the Agency to consider available

inform ation on cum u lative risk from substances sharing a com m on m echanism of toxicity, such as the toxicity expressed by the triazine herbicides through a com m on biochem i cal m echanism

, the Agency will evaluate the cum u lative risk posed by the entire triazine class of chem icals af ter considering the risks for the individual triazines. The Agency is working towards com p letion of

a m e thodology to assess cum u lative risk and the individual risk assessm ents for each triazine are likely to be necessary elem ents of any cum u lative assessm ent. The Agency has decided to m ove f

o rward with individual assessm ents and to identif y m itigation m easures necessary to address

those hum an health and environm ental risks associated with the current uses of atrazine. The Agency will issue the f i nal tolerance reassessm ent decision f o r atrazine and f i nalize decisions on reregistration eligibility once the cum u lative risks f o r all of the triazines are considered.

This docum ent contains a generic and/or a product-specific Data Call-In(s) (DCI) that outline(s) f u rther data requirem e nts f o r this chem ical. Note that a com p lete DCI, with all pertinent instructions, is being sent to registrants under a separate cover. Additionally, for product-specific DCIs, the first set of required responses is due 90 days from the receipt of the

DCI letter. The second set of required responses is due eight m onths from the date of the DCI.

The Agency has determ ined that atrazine is eligible for reregistration provided that all the

conditions identif ied in this docum ent are satisf i ed, including im plem entation of the interim risk

m itigation m easures outlined in Section IV of the docum ent. This determ ination does not include

consideration of the cum u lative risk from the use of the triazines. The Agency believes that certain current uses of atrazine pose unreasonable adverse effects to hum an health and the

environm ent, and that such ef f

ects can be m itigated with the risk m itigation m e asures identif ied

in this interim RED. Accordingly, the Agency recom m e nds that registrants im plem ent these

interim risk m itigation m easures im m e diately. Section V of this interim RED describes labeling

am endm ents for end-use products and data requirem e nts necessary to im plem ent these interim

m itigation m easures. Instructions f o r registrants on subm itting revised labeling and the tim e fram e established to do so can be found in Section VI of this docum ent.

Should a registrant fail to im plem ent any of the risk m itigation m easures outlined in this

docum ent, the Agency will undertake appropriate action to address concerns about the risks posed by atrazine. W h ere the Agency has identified any unreasonable adverse effect to hum an health or the environm ent, the Agency m u st take action to address this concern. At that tim e, any affected person(s) m a y challenge the Agency’s action.

5If you have questions on this docum ent or the label changes necessary for reregistration, please contact the Chem ical Review Manager, Kim b erly Nesci at (703) 308-8059. For questions about product reregistration and/or the Product DCI that accom p anies this docum ent, please contact Bonnie Adler at (703) 308-8523.

Sincerely,

Lois A. Rossi, Director Special Review and Reregistration Division

Attachm e nt

6

## Interim Reregistration Eligibility Decision

for

Atrazine

Case No. 0062TABLE OF CONTENTS

Atraz i ne Team

............................................................... v

Glossary of Terms and Abbreviations

.......................................... v i i

Executive Summary

........................................................... 1

I. Introduction

............................................................ 7

II. Chemical Overview

...................................................... 9

A. Regulatory History

................................................. 9

B. Chemical Identification

............................................. 1 1

C. Use Profile

........................................................ 1 2

D. Estimated Usage of Pesticide

........................................ 1 3

III. Summary of Atraz i ne Risk Assessments

.................................... 1 5

A. Human Health Risk Assessment

...................................... 1 5

1. Dietary Risk From Food

....................................... 1 6

a. Toxicity and Carcinogenicity

.......................... 1 6 1) Atraz i ne and the Chlorinated Metabolites

.... 1 6 2) Hydroxyatraz i ne

.......................... 1 7

b. FQPA Safety Factor

................................. 1 7 1) Atraz i ne and the Chlorinated Metabolites

..... 1 7 2) Hydroxyatraz i ne

.......................... 1 8

c. Population Adjusted Dose

............................ 1 9

d. Exposure Assumptions

............................... 2 0

e. Food Risk Characteriz a tion

........................... 2 0 1) Atraz i ne and Its Chlorinated Metabolites

..... 2 1 2) Hydroxyatraz i ne

.......................... 2 1

2. Dietary Risk from Drinking Water

.............................. 2 1

a. Drinking Water Levels of Comparison (DWLOC)

....... 2 2 1) Community Water Systems (CWS) Using Surface

Water

................................... 2 3 2) Groundw ater

............................. 2 5 3) Domestic Rural Wells

...................... 2 6

2. Residential Risk

.............................................. 2 6

a. Toxicity

........................................... 2 7

b. Exposure Assumptions

............................... 2 8

c. Residential Applicator Risk

........................... 2 9

d. Post-Application Residential Risk

...................... 3 0

3. Aggregate Risk

............................................... 3 2

a. Acute Aggregate Exposure and Risk Estimates

........... 3 2

b. Intermediate-Term and Chronic Aggregate Exposure and

iRisk Estimates

...................................... 3 3

c. Short-Term Aggregate Exposure and Risk Estimates

..... 3 3 1) Adult Handlers

........................... 3 3 2) Adult Post-Application

..................... 3 4 3) Child Post-Application

..................... 3 5

4. Occupational Risk

............................................ 3 6

a. Toxicity

........................................... 3 6

b. Occupational Exposure

.............................. 3 8

c. Occupational Handler Risk Summary

.................. 3 9 1) Agricultural Handler Risk

.................. 3 9 2) Law n Care Operator Handler Risk

.......... 5 0 3) Post-Application Occupational Risk

......... 5 2 4) Epidemiology Data

........................ 5 2

B. Environmental Risk Assessment

...................................... 5 3

1. Environmental Fate and Transport

.............................. 5 3

2. Risk to Terrestrial Organisms

.................................. 5 6

a. Toxicity (Haz ard) Assessment

......................... 5 7

b. Exposure and Risk - Birds and Mammals

............... 5 8

c. Exposure and Risk - Terrestrial Plants

................. 6 0

3. Risk to Aquatic Species

........................................ 6 1

a. Toxicity (Haz ard) Assessment

......................... 6 1

b. Exposure and Risk

.................................. 6 3

5. Refined Aquatic Assessment

.................................... 6 5

a. Ponds

............................................. 6 9

b. Lakes and Reservoirs

................................ 6 9

c. Streams

........................................... 7 0

d. Estuaries

.......................................... 7 0

6. Risk to Endangered Species

..................................... 7 1

7. Ecological Incident Reports

..................................... 7 2

8. Endocrine Disruption

.......................................... 7 3

IV. Interim Risk Management and Reregistration Decision

....................... 7 5

A. Determination of Interim Reregistration Eligibility

...................... 7 5

B. Summary of Phase 5 Comments and Responses

......................... 7 6

C. Regulatory Position

................................................ 7 8

1. FQPA Assessment

............................................. 7 8

a. “Risk Cup” Determination

........................... 7 8

b. Tolerance Summary

................................. 7 9

3. Codex Harmoniz ation

......................................... 8 4

4. Endocrine Disruptor Effects

.................................... 8 4

5. Labels

....................................................... 8 5

a. Agricultural Use Exposure Reduction Measures

......... 8 5 1) Mixing/Loading Scenarios :

................. 8 6

ii2) Applicator and Flagger Scenarios:

......................................... 8 6

b. Non-Agricultural Use Exposure Reduction Measures

..... 8 7 1) Non-Agricultural Products including Law n s and Turf (not Sod Farms)

...................... 8 7 2) Residential

............................... 8 7

c. Label Harmoniz ation

................................ 8 7

D. Regulatory Rationale

............................................... 8 9

1. Human Health Risk Mitigation

.................................. 8 9

a. Dietary (Food)

...................................... 8 9

b. Dietary (Drinking Water)

............................ 8 9 1) Community Water Systems (CWS)

........... 8 9 2) Rural Drinking Water Wells

................ 9 2

b. Residential Risk Mitigation

........................... 9 3 1) Residential Handler Risk

................... 9 3 2) Residential Post-Application Risk

............ 9 3

c. Aggregate Risk Mitigation

............................ 9 3 1) Acute Exposure

........................... 9 4 2) Intermediate-Term and Chronic Exposure

.... 9 4 3) Short-Term Aggregate Exposure

............ 9 4

d. Occupational Risk Mitigation

......................... 9 5 1) Mixing/Loading Scenarios

.................. 9 6 2) Applicator and Flagger Scenarios

........... 9 6

3. Non-Agricultural Products includi ng Law n s and Turf (not Sod Farms) 97

2. Environmental Risk Mitigation

................................. 9 8

3. Other Labeling

............................................... 9 8

a. Endangered Species Statement

........................ 9 9

b. Spray Drift Management

............................. 9 9

V. What Registrants Need to Do

............................................ 1 0 1

A. Manufacturing Use Products

....................................... 1 0 1

1. Additional Generic Data Requirements

.......................... 1 0 1

2. Labeling for Manufacturing Use Products

....................... 1 0 3

B. End-Use Products

................................................. 1 0 3

1. Additional Product-Specific Data Requirements

.................. 1 0 3

2. Labeling for End-Use Products

................................ 1 0 3

C. Existing Stocks

................................................... 1 0 3

D. Labeling Changes Summary Table

.................................. 1 0 4

Appendix A : ATRAZ INE USE PATTERNS ELIGIBLE FOR

REREGISTRATION

......................................... 1 2 7

iiiAppendix B : STUDIES USED TO SUPPORT THE REREGISTRATION OF

ATRAZ INE

................................................. 1 5 3

Appendix C : TECHNICAL SUPPORT DOCUMENTS

........................ 1 6 9

Appendix D : CITATIONS CONSIDERED TO BE PART OF THE DATA BASE

SUPPORTING THE INTERIM REREGISTRATION DECISION (BIBLIOGRAPHY)

.......................................... 1 7 3

Appendix F : PRODUCT SPECIFIC DATA CALL-IN

........................ 2 6 7

Appendix G : EPA'S BATCHING OF ATRAZ INE PRODUCTS FOR MEETING ACUTE TOXICITY DATA REQUIREMENTS FOR

REREGISTRATION

......................................... 2 7 7

Appendix H : ATRAZ INE MONITORED WATERSHEDS

..................... 2 8 7

ivAtraz i ne Team

Office of Pesticide Program s:

Health Effects Risk Assessm ent

Gary Bangs

Vicki Dellarco

Catherine Eiden

Artensie Flowers Linda Taylor

Environm ental Fate Risk Assessm ent

Tim Bargar

Kevin Costello Mary Frankenberry

Jam e s Lin

W illiam Rabert

Thom as Steeger Douglas Urban

Use and Usage Analysis

Neil Anderson

Nicole Mosz

Steve Sm earm a n Philip Villanueva Virginia W e rling

Registration Support

Philip Errico

Edith Minor

Jim Tom pkins

Risk Managem e nt

Mark Hartm a n Kim b erly Nesci

vviGlossary of Terms and Abbreviations

AE Acid Equivalent

a.i. Active Ingredient

AGDCI A gricultural Data Call-In

ai Active Ingredient

aPAD Acute Population Adjusted Dose

AR Anticipated Residue

ARC Anticipated Residue Contribution

BCF Bioconcentration Factor

CAS C hem i cal Abstracts Service

CI Cation

CNS C entral Nervous System

cPAD Chronic Population Adjusted Dose

CSF C onf idential Statem ent of Form ula

CFR C ode of Federal Regulations

CSFII U SDA Continuing Surveys for Food Intake by Individuals

DCI D ata Call-In

DEEM Dietary Exposure Evaluation Model

DFR D islodgeable Foliar Residue

DRES Dietary Risk Evaluation System

DW EL Drinking W a ter Equivalent Level (DW EL) The DW EL represents a m e dium specific (i.e., drinking water) lifetim e exposure at which adverse, noncarcinogenic health effects are not anticipated to occur.

DW LOC D rinking W a ter Level of Com p arison.

EC Em ulsifiable Concentrate Form ulation

EEC Estim ated Environm ental Concentration. The estim ated pesticide concentration

in an environm ent, such as a terrestrial ecosystem

. EP End-Use Product

EPA U .S. Environm ental Protection Agency

FAO F ood and Agriculture Organization

FDA F ood and Drug Adm i nistration

FIFRA F ederal Insecticide, Fungicide, and Rodenticide Act

FFDCA Federal Food, Drug, and Cosm etic Act FQPA Food Quality Protection Act

FOB F unctional Observation Battery

G G ranular Form ulation

GENEEC Tier I Surface W a ter Com puter Model

GLC G as Liquid Chrom a tography

GLN G uideline Num b er GM Geom etric Mean

GRAS Generally Recognized as Safe as Designated by FDA

HA Health Advisory (HA). The HA values are used as inform al guidance to

viim unicipalities and other organizations when em ergency spills or contam ination

situations occur.

HAFT H ighest Average Field Trial

HDT Highest Dose Tested

IR Index Reservoir

LC 50 Median Lethal Concentration. A statistically derived concentration of a substance that can be expected to cause death in 50% of test anim als. It is usually expressed as the weight of substance per weight or volum e of water, air or feed, e.g., m g /l,

m g /kg or ppm

. LD 50 Median Lethal Dose. A statistically derived single dose that can be expected to

cause death in 50% of the test anim als when adm i nistered by the route indicated (oral, derm al, inhalation). It is expressed as a weight of substance per unit weight

of anim al, e.g., m g /kg.

LEL Lowest Effect Level

LOC L evel of Concern

LOD L im it of Detection

LOAEL L owest Observed Adverse Effect Level

MATC Maxim u m Acceptable Toxicant Concentration

MCLG Maxim u m Contam inant Level Goal. The MCLG is used by the Agency to regulate contam inants in drinking water under the Safe Drinking W a ter Act.

m g /kg/day M illigram Per Kilogram Per Day

m g /L Milligram s Per Liter

MOE M argin of Exposure

MP Manufacturing-Use Product

MPI M axim um Perm issible Intake

MRID Master Record Identification (num ber). EPA' s system of recording and tracking

studies subm itted.

NA Not Applicable

N/A N ot Applicable

NAW QA USGS National W a ter Quality Assessm ent
NOEC N o Observable Effect Concentration

NOEL N o Observed Effect Level

NOAEL N o Observed Adverse Effect Level

NPDES N ational Pollutant Discharge Elim ination System

NR Not Required

OP Organophosphate

OPP E PA Office of Pesticide Program s OPPTS E PA Office of Prevention, Pesticides and Toxic Substances

Pa Pascal, the pressure exerted by a force of one newton acting on an area of one

square m e ter.
PAD P opulation Adjusted Dose

PADI Provisional Acceptable Daily Intake

PAG P esticide Assessm ent Guideline

PAM P esticide Analytical Method

viiiPCA P ercent Crop Area

PCO P est Control Operator

PDP U SDA Pesticide Data Program

PHED Pesticide Handler' s Exposure Data

PHI P reharvest Interval ppb Parts Per Billion

PPE Personal Protective Equipm ent

ppm Parts Per Million

PRN P esticide Registration Notice

PRZM/

EXAMS T ier II Surface W a ter Com puter Model Q 1 * T he Carcinogenic Potential of a Com pound, Quantified by the EPA' s Cancer Risk

Model

RAC R aw Agriculture Com m odity

RBC Red Blood Cell

RED R eregistration Eligibility Decision

REI R estricted Entry Interval

RfD R eference Dose RQ Risk Quotient

RS Registration Standard

RUP R estricted Use Pesticide

SAP S cience Advisory Panel

SCI-GROW T ier I Ground W a ter Com puter Model

SF Safety Factor

SLC S ingle Layer Clothing

SLN S pecial Local Need (Registrations Under Section 24(c) of FIFRA)

TC Toxic Concentration. The concentration at which a substance produces a toxic

effect.

TD Toxic Dose. The dose at which a substance produces a toxic effect.

TEP Typical End-Use Product

TGAI Technical Grade Active Ingredient

TLC Thin Layer Chrom a tography

TMRC Theoretical Maxim u m Residue Contribution

torr A unit of pressure needed to support a colum n of m e rcury 1 m m high under

standard conditions.

TRR T otal Radioactive Residue

UF Uncertainty Factor

F g/g M icrogram s Per Gram

F g/L M icrogram s Per Liter

USDA United States Departm e nt of Agriculture

USGS United States Geological Survey

UV Ultraviolet

W H O W orld Health Organization

WP We t t a b l e P o w d e r

ixW P S W orker Protection Standard

xExecutive Summary

EPA has com p leted its review of public com m e nts concerning the revised atrazine risk

assessm ents and is issuing its interim risk m a nagem e nt decision for atrazine. The revised risk

assessm ents are based on the Agency’s review of available data on the currently registered uses of atrazine and public com m e nts received during th e reregistration process. The Agency invited stakeholders to provide proposals, ideas or suggestions on appropriate m itigation m e asures bef o re the Agency issued its risk m itigation decision f o r atrazine. Af ter considering the risks identified, public com m e nts, and m itigation options proposed by several entities, the Agency developed its interim risk m a nagem e nt decision fo r atrazine. This decision is discussed fully in

this docum ent and in a January 31, 2003, Mem o randum of Agreem ent between the Agency and the prim ary technical registrant, Syngenta Crop Pr otection, Inc. The Agency expects the atrazine technical registrants to agree to adopt the risk m a nagem e nt m easures presented in the IRED and

in the MOA. Neither the risk assessm ents nor the interim risk m a nagem e nt m easures include

consideration of cum u lative risks posed by all of the triazines and am phibian risk issues.

Atrazine is a triazine herbicide currently registered for use against broadleaf and som e grassy weeds. Atrazine is currently registered for use on corn (field and sweet); guavas;

m acadam ia nuts; sorghum ; sugarcane; range grasses for the establishm ent of perm anent grass cover on rangelands and pastures under USDA’s Conservation Reserve Program (CRP) in OK, NE, TX, and OR; wheat (where application is to wheat stubble on fallow land following wheat harvests; wheat is not the target crop); conifer forests; Christm a s tree farm s; sod farm s; golf courses and residential lawns (Southern turfgrasses). Given the specific nature of the lawn uses,

m u ch of atrazine’s use on lawns is confined to Florida and the Southeast. Atrazine degrades into hydroxy com pounds and chlorotriazine degradates. Atrazine was first registered in 1958 as an

herbicide. Use data from 1990 to 1997 indicate that approxim a tely 76.5 m illion pounds of atrazine active ingredient are used dom estically each year.

The Food Quality Protection Act of 1996 (FQPA) requires that, when considering whether to establish, m odify, or revoke a tolerance, the Agency consider “available inform ation” concerning the cum u lative effects of a particular pesticide’s residues and other substances that

have a com m on m echanism of toxicity with other pesticides. The Agency has classified the triazine herbicides (atrazine, sim azine, and propazine) and their com m on chlorinated degradates as having a com m on m echanism of toxicity. The Agency has not yet com p leted its cum u lative

risk assessm ent f o r the triazine class, but the cum u lative risks of these chem icals will be

considered in the future. At that tim e, the Agency’s final tolerance reassessm ent decision for

atrazine and the other triazines will be issued. The Agency m a y need to pursue f u rther risk

m itigation f o r atrazine to address any risks identif ied in the cum u lative assessm ent f o r the

triazines.

Overall Risk Sum m a ry

1The Agency’s hum an health risk and ecological risk assessm ents for atrazine indicate

risks of concern. Interm ediate-term (seasonal) dietary risk from drinking water exceeds the Agency’s level of concern (>100% cPAD) at the 99.9 th exposure percentile for infants, children 1-6 years of age, and adults in 34 com m unity water system s (CW S ) prim arily in the Midwest. Acute dietary drinking water risks, and acute and chronic dietary food risks (alone) are below the Agency’s level of concern for the U.S. population and all population subgroups.

Further, there are som e concerns for workers who m i x, load and apply atrazine to agricultural and turf sites and for hom eowners who apply atrazine products to hom e lawns. In addition, there are risks of concern for adults and children exposed to atrazine treated lawns after applications.

For ecological effects, the Agency has conducted a screening level assessm ent for

terrestrial im pacts and a refined exposure assessm ent for aquatic im pacts of atrazine use. These

assessm ents indicate that atrazine is likely to result in com m unity- and population-level risk at 10 to 20 ppb. The ecological assessm ent does not address the potential for effects on am phibians endocrinology and reproductive and developm ental responses. The Agency will consider

am phibian risk af ter the Agency obtains f u rther data and will address any risks identif ied in a revision to the IRED to be published by October 31, 2003.

To m itigate risks of concern posed by the uses of atrazine, the Agency considered the

m itigation proposal subm itted by the technical registrants, as well as com m e nts and m itigation

ideas from other interested parties, and has decided on a num ber of label am endm ents to address the dietary (drinking water), worker, and residential concerns. In addition, to further address drinking water concerns and to address ecological concerns, the Agency and the technical registrants have agreed to a perform a nce standard for atrazine that m u st be m e t in com m unity

water system s, prohibition of use in watersheds if the standard is not m e t, and m onitoring data requirem e nts as described in the Mem o randum of Agreem ent. Results of the risk assessm ents, the necessary label am endm ents to m itigate those risks, and inf o rm ation on the Agreem ent between the Agency and the technical registrants are presented in this IRED.

Dietary Risk (Food)

Acute risk estim ates for food and drinking water and chronic food risk estim ates do not exceed the Agency’s level of concern; therefore, m itigation m easures are not needed to address acute dietary risks or chronic food risk estim ates.

Dietary Risk (Drinking W a ter)

Interm ediate-term (seasonal) drinking water risk estim ates do exceed the Agency’s level

of concern in 34 CW S prim arily in the Midwest. The registrant has added three CW S to these 34

to m a ke a total of 37 CW S that are of concern. To m itigate these risks, the Agency has

determ ined that a perform a nce standard that m u st be m e t in these CW S and prohibiting use in the watershed if the perform a nce standard is not m e t is necessary to avoid unreasonable adverse

2effects. In addition, the Agency is requiring extensive m onitoring data on these CW S and other

CW S that are in atrazine use areas.

To confirm that risks from atrazine in rural wells is not a concern, the Agency is requiring m onitoring data for atrazine levels in rural wells in atrazine use areas.

Residential Risk

Residential and turf use results in risks of concern for children reentering treated atrazine

turf and for hom eowners applying product to turf using a bellygrinder.

Restrict the application of granular lawn products when using hand-held devices (e.g. belly grinder) to spot applications only.

C Prohibit applications of granular lawn products by hand

C Reduce the m a xim u m single application rate for liquid form ulations on residential lawns

and turf to 1 lb ai/A from 2 lb ai/A (liquid products containing >4% ai are restricted use)

C Require that granular lawn products be watered in

Occupational Risk

Occupational exposure to atrazine is of concern to the Agency. For agricultural and turf lawn care operator uses of atrazine, several m i xer/loader/applicator risk scenarios currently exceed the Agency’s level of concern at baseline PPE or label PPE. The Agency has determ ined

that a num ber of m easures are needed to m itigate these risks, as f o llows:

Agricultural Uses

1) Mixing/Loading Scenarios: Liquids:

C require closed system s for m i xing/loading to support aerial applications at greater than 3 lb ai/A

C all m i xers/loaders (including using engineering controls) m u st wear longsleeve shirt, long pants, shoes, socks, chem ical-resistant gloves and

chem ical resistant apron

W e ttable Powders:

C require water-soluble packaging for all W P form ulations

C all m i xers/loaders m u st wear long-sleeve shirt, long pants, shoes, socks,

chem ical-resistant gloves and chem ical resistant apron Dry Flowables:

C water-soluble packaging optional

C if in water-soluble packaging, all m i xers/loaders m u st wear long-sleeve shirt, long pants, shoes, socks, chem ical-resistant gloves and chem ical resistant apron

C if not in water-soluble packaging, m i xers/loaders m u st wear coveralls over

3long-sleeve shirt and long pants, chem ical-resistant gloves, chem icalresistant footwear, and chem ical-resistant apron plus a NIOSH-approved

dust/m ist f iltering respirator with any N, R, P, or HE f ilter.

C if not in water-soluble packaging, aerial application is prohibited.

Granular Products:

C Loaders m u st wear long-sleeve shirt, long pants, shoes, and socks.

2) Applicator and Flagger Scenarios:

C Pilots m u st use enclosed cockpits (40 CFR 170.240(d)(6)) for aerial applications.

C Hum a n flaggers supporting aerial applications m u st used enclosed cabs (40 CFR 170.240(d)(5)).

C Applicators applying sprays with m o torized ground equipm ent (i.e., groundboom or rights-of-way sprayers) m u st wear long-sleeve shirt, long pants, shoes, socks,

and chem ical-resistant gloves.

C Applicators applying granular products or im pregnated fertilizer m u st wear longsleeve shirt, long pants, shoes, and socks.

C Restrict the im pregnation of bulk f e rtilizer to com m e rcial facilities (prohibit onfarm im pregnation)

C Restrict the im pregnation of dry bulk fertilizer to 500 tons per day for no m o re than 30 days per calender year per f acility

C Reduce the m a xim u mapplication rate for handlers applying liquids with rightsof-way sprayers to 1.0 lb ai/A

C Reduce the m a xim u m application rate for liquids for chem ical follow to 2.25 lb

ai/A

C Require a 60-day PHI for field corn forage uses

C Require a 45-day PHI for sweet corn forage uses

C Require a 60-day PHI for preem ergent uses and a 45-day PHI for postem e rgent sorghum forage uses

Non-Agricultural Products including Lawns and Turf (not Sod Farms)

C Require that all wettable powder products be packaged in water soluble bags.

C Granular form ulations: loaders, applicat ors, and other handlers m u st wear longsleeve shirt, long pants, shoes, and socks.

C Liquid, wettable powder, dry flowable (water-dispersible granule) form ulations:

- a pplicators using spray equipm ent m ounted on their backs m u st wear coveralls worn over long sleeved shirt and long pants, chem ical-resistant gloves and

chem ical-resistant footwear plus socks.

- a ll other m i xers, loaders, applicators, and other handlers m u st wear long-sleeved shirt and long pants, shoes and socks, and chem ical resistant gloves.

C Reduce the m a xim u m single application rate for liquid form ulations on residential lawns

and turf to 1 lb ai/A from 2 lb ai/A (liquid products containing >4% ai are restricted use)

C Require that granular lawn products be watered in

4The Agency does not have risks of concern for workers reentering treated fields;

theref ore, no m itigation is needed.

Ecological Risk

Ecological risks are also of concern to the Agency. The environm ental risk assessm ent suggests that exposure to atrazine could result in com m unity-level and population-level effects in aquatic com m unities at concentrations of 10-20 ppb atrazine.

To address these risks, the Agency has determ ined that an ecological assessm ent process to identify waterbodies at risk and m onitor these waterbodies for atrazine concentrations. In addition, it m a y be necessary to undertake m itigation in these vulnerable ecosystem s. The specif i cs of this ecological program will be negotiated with the technical registrants and agreed to by April 30, 2003.

The ecological assessm ent does not address the potential for effects on am phibian endocrinology and reproductive and developm ental responses. The Agency will consider

am phibian risk af ter the Agency obtains f u rther data on this issue. Any risks identif ied will be addressed by the Agency in a revision to the IRED to be published by October 31, 2003.

Conclusions

The Agency is issuing this interim Reregistration Eligibility Decision (IRED) f o r atrazine, as announced in a Notice of Availability published in the Federal Register. This IRED includes guidance and tim e fram es for im plem enting label changes for products containing

atrazine. Note that the Agency has shortened the tim e period for im plem entation of risk

m itigation m easures outlined in this docum ent and to establish m onitoring program s so that the risks identified herein are addressed as quickly as possible. There is a 60-day com m e nt period

on this docum ent. W ith the m itigation m easures detailed in this docum ent, the Agency has

determ ined that, until the cum u lative risks f r om all the triazines has been considered, m o st of the currently registered uses of atrazine m a y continue. Neither the tolerance reassessm ent nor the reregistration eligibility decision f o r atrazine can be considered f i nal until the cum u lative risk f o r all triazines is considered.

56I. Introduction

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was am ended in 1988 to accelerate the reregistration of products containing active ingredients originally registered prior to Novem b er 1, 1984. The am ended Act calls for the developm ent and subm ission of data to support the reregistration of an active ingredient, as well as a review of all subm itted data by

the U.S. Environm ental Protection Agency (EPA or “the Agency”). Reregistration involves a thorough review of the scientific database supporting a pesticide’s registration. The purpose of the Agency’s review is to reassess the potential hazards and benefits arising from the currently registered uses of the pesticide; to determ ine if there is a need for additional data on benefits,

health and environm ental effects; and to determ ine whether the pesticide m e ets the “no

unreasonable adverse effects” criteria of FIFRA.

On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) was signed into

law. This Act am ends the Federal Food, Drug and Cosm etics Act (FFDCA) to require

reassessm ent of all existing tolerances. The Agency had decided that, for those chem icals that have tolerances and are undergoing reregistration, the tolerance reassessm ent will be initiated through this reregistration process. It also requires that by 2006, EPA m u st review all tolerances in effect as of August 2, 1996 (the day before FQPA was enacted). FQPA also am ends the FFDCA to require a safety finding in tolerance reassessm ent based on several factors, including

an assessm ent of cum u lative effects of chem icals with a com m on m e chanism of toxicity. Atrazine belongs to a group of system ic herbicides called triazines that share a com m o n

m echanism of toxicity. Agency is continuing its reregistration program while it resolves the

rem a ining issues associated with the im plem entation of FQPA.

This docum ent presents the Agency’s revised hum an health and ecological risk

assessm ents; its progress toward tolerance reassessm ent; and the interim decision on the reregistration eligibility of atrazine. It is intended to be only the f i rst phase in the reregistration process for atrazine. The Agency will eventually proceed with its assessm ent of the cum u lative

risk of the triazine pesticides and issue a f i nal reregistration eligibility decision f o r atrazine.

The im plem entation of FQPA has required the Agency to revisit som e of its existing views relating to the determ ination and regulation of dietary risk, and has also raised a num ber of

new issues that need to be addressed. These issues were refined and developed through collaboration between the Agency and the Tolerance Reassessm ent Advisory Com m ittee (TRAC), a com m ittee that was com posed of representatives from industry, environm ental groups, and other interested parties.

This interim Reregistration Eligibility Decision docum ent consists of six sections. Section I contains the regulatory fram ework for reregistration/tolerance reassessm ent. Section II provides a profile of the use and usage of the chem ical. Section III gives an overview of the

revised hum an health and environm ental effects risk assessm ents resulting from public

com m e nts and other inform ation. Section IV presents the Agency' s interim decision on reregistration eligibility and risk m a nagem e nt decisions. Section V sum m a rizes the label

7changes necessary to im plem ent the risk m itigation m easures outlined in Section IV. Section VI provides inform ation on how to access related docum ents. Finally, the Appendices list Data Call-In (DCI) inform ation. The revised risk assessm ents and related addenda are not included in

this docum ent, but are available on the Agency' s web page: “www.epa.gov/pesticides/reregistration,” and in the Public Docket.

8II. Chemical Overview

A. Regulatory History

Atrazine was first registered in 1958 as an herbicide. On Novem b er 10, 1983, a Registration Standard for atrazine was issued. This docum ent noted the Agency’s concern about the dietary carcinogenic risk from ground and su rface water contam ination. The Registration Standard also required the subm ission of generic and product-specific data to support the continued registration of atrazine products. Si nce the Registration Standard was issued in 1983, there have been a total of 4 DCIs issued (Septem b er 1990, Septem ber 1992, March 1995, October 1995).

In 1988, EPA issued a prelim inary notification of the Agency’s intention to initiate Special Review under FIFRA based on concerns regarding the carcinogenic potential of atrazine and possible risks resulting from exposure to atrazi ne in the diet from treated food and drinking

water.

In the early 1990s, atrazine' s occurrence in the environm ent prom pted the Environm ental Protection Agency’s Office of W a ter (OW ) to regulate atrazine under the Safe Drinking W a ter Act (SDW A). In 1991 OW established a Maxim u m Contam inant Level (MCL) of 3 parts per billion (ppb) for atrazine. Under the SDW A , atrazine has been subject to com p liance

m onitoring. OW has also established a one-day Health Advisory Level (HAL) for atrazine of 100 ppb.

In the early 1990s, the registrant voluntarily instituted several risk reduction m e asures to address concerns raised about surface water and groundwater contam ination by atrazine. In 1990, the following m easures were undertaken by the registrant to address groundwater exposure

concerns:

C Reduction of the application rate for corn and sorghum to 3.0 lbs ai/acre from 4.0

lbs ai/acre.

C Reduction of the m a xim u m rate for non-cropland and total vegetation control to

10 lbs ai/acre from 40 lbs ai/acre.

C Require that postem e rgence applications to corn and sorghum be m a de before they reach 12 inches in height.

C Deletion of rangeland, proso m illet, and pineapple uses.

C Prohibition of chem igation (applying atrazine through irrigation system s).

C Institution of a well-head protection plan requiring 50 foot setbacks around all

wells for m i xing, loading, or applying atrazine-containing products.

• I nstitution of construction requirem e nts f o r bulk storage f acilities to prevent point

source contam ination f r om spills

• C lassification of all atrazine-containing products (except for the lawn care, turf, and conifer uses) as Restricted Use Pesticides (RUPs).

9In 1992, the following additional m easures were undertaken to address concerns about

atrazine contam ination of surface water sources:

• F urther reduction of the total seasonal application rates for corn and sorghum to
2.5 lbs ai/acre per year. This rate includes a 1.5 lbs ai/acre per year pre-em ergence use and a 1.0 lbs ai/acre per year post-em ergence use.

• D eletion of all uses for total vegetation control in non-cropland.

• E xpansion of restricted use criteria to include surface water concerns.

• E xpansion of the setback requirem e nts, including: a 50 foot setback around

surface water sources when workers are m i xing and loading atrazine-containing products; a 66 foot application (ground and aerial) setback from points of entry where field surface water runoff enters surface water sources; and, a 200 foot application setback around lakes and reservoirs.

In Novem b er 1994, EPA initiated a Special Review for the triazine pesticides (atrazine,

sim azine and cyanazine; 59 FR 60412) based on cancer risk concerns for people potentially exposed to atrazine through consum ption of food and drinking water, and lawn treatm e nts. The basis for the Special Review also included cancer risk concerns for workers exposed to atrazine in various agricultural settings and application scenarios. At the tim e that the Special Review was initiated, atrazine and the other triazines we re classified as Group C carcinogens (possible

hum an carcinogens).

Further labeled use restrictions in 1996 reduced environm ental exposure fromtileterraced fields containing standpipes, as follows:

• R estrictions against application within 66 feet of standpipes.

• A requirem e nt that applications be incorporated to a depth of 2 to 3 inches.

• R estrictions against application to no-till f i elds unless practicing high crop

residue m a nagem e nt.

In August 2002, the Agency and NRDC jointly agreed to request that the court extend the deadline for the IRED to January 31, 2003 (Consent Decree (as am ended) entered in Natural

Resources Defense Council v. W h itm an , Case Num b er C -99-3701 CAL, N. D. California (2002)). The new schedule includes the com p letion of an IRED by January 31, 2003 (this

docum ent), and a revised IRED by October 31, 2003, to consider a num ber of additional new studies on potential am phibian risk. The Agency also agreed to bring to the FIFRA Scientific Advisory Panel issues regarding am phibian effects and carcinogenicity.

10B. Chemical Identification

• C hemical Structure:

• Common name: Atrazine

• Chemical name: 6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4­

diam ine

• C hemical family: Triazines

• C ase number: 0062

• CAS registry number: 1912-24-9

• OPP chemical code: 080803

• Empirical formula: C 8 H 14 ClN 5

• Molecular w eight: 215.7

• Vapor Pressure: 40 u Pa at 20 E C

• Technical registrants: Agan Chem ical Manufacturing, LTD. Dow AgroSciences

Drexel Chem ical Com p any Oxon Italia S.P.A.

Platte Chem ical Com p any Inc. Syngenta Crop Protection Inc.

Atrazine is a white crystalline solid with a m e lting point of 172-175 E C, density of 0.35 g/m L , octanol/water partition coef f i cient (log P

ow ) of 2.7645, and vapor pressure of 40 F Pa at

20 E C. Atrazine is m oderately soluble in water (33 ppm at 25 E C), and is soluble in octanol (0.82 g/100 m L ), ether (0.86 g/100 m L ), m e thanol (1.4 g/100 m L ), ethyl acetate (2.5 g/100 m L ),

and chloroform (7.8 g/100 m L ) at 20 E C. Atrazine has four hydroxyatrazine com pounds and

three chlorinated atrazine com pounds as m e tabolites. The three chlorinated m e tabolites are desethylated atrazine, desisopropyl atr azine, and diam inochlorotriazine (DACT).

C. Use Profile

11Atrazine is a system ic triazine herbicide regi stered for the control of broadleaf weeds and

som e grassy weeds. Currently, atrazine is one of the two m o st widely used agricultural pesticides in the United States. An estim ated average of approxim a tely 64 to 76 m illion pounds of active ingredient are applied per year. Annua lly, 75% of all field corn, 58.5% of all sorghum

, and 76% of all sugarcane grown are treated with at razine. Most of atrazine applied to corn and sorghum is applied pre-em ergence. The following inform ation is based on the currently registered uses of atrazine that were origina lly being supported for reregistration. Appendix A at

the end of this docum ent presents a sum m a ry of eligible uses and revised use conditions.

Type of Pesticide: Triazine Herbicide

Summary of Use Sites:

Food : Atrazine is used on corn (field and sweet), guavas, m acadam ia nuts, sorghum , sugarcane, range grasses under USDA’s Conservation Reserve Program (CRP), and wheat (where application is to wheat stubble on fallow land following wheat harvests; wheat is not the target crop)

Other Agricultural Sites : Atrazine is also used in conifer forests, on Christm a s tree farm s and on sod farm s.

Residential : Atrazine is used on golf courses and residential lawns. Given the specific nature of the lawn uses, m u ch of atrazine’s use on lawns is confined to

Florida and the Southeast.

Other Sites: Atrazine in used on range grasses for the establishm ent of perm anent grass cover on rangelands and pastures under the Conservation Reserve Program (CRP) in four states: OK, NE, TX, and OR.

Public Health : None

Target Pests: Broadleaf and som e grassy weeds.

Formulation Types Registered :

Form ulated as a flowable concentrate, a water dispersable granular (dry flowable), a ready-to-use product, and a granular.

Method and Rates of Application :

Equipm ent : Atrazine m a y be applied by groundboom sprayer, aircraft, tractor-drawn spreader, rights-of-way sprayer, low pressure handwand, backpack sprayer, lawn handgun, push-type spreader, and bellygrinder.

12Rates : Maxim u m application rates range from 0.4 lb ai/A or lb ai/gal to

4.0 lb ai/A or lb ai/gal (conifer forests, sugarcane, Christm a s tree farm s, sod farm s (FL), Berm uda grass highway rights-of-way). The num ber of

m a xim u m allowable applications ranges between 1 and 4 per season or year, when specified.

Timing:

Sugarcane : Applications to sugarcane are usually at planting (fall), in the spring

after em ergence, and an additional post-em ergence application (often at layby (canopy closure)). However, these later applications are only used if pest pressure dictates need. Also, ratoon crops m a y face heavier weed pressure, and therefore additional applications are m o re likely during ratoon crops.

Corn : Applications to corn are m o st often pre-em ergence (m id-April through

m i d-May in the m a jor corn growing areas). Post-em e rgence applications are m o st likely to occur up to the end of June, until corn reaches 12" in height. There will

be som e variability in tim ing based on geographical regions.

Sorghum : Applications to corn are m o st often pre-em ergence (m id-June to m i dJuly in the m a jor sorghum growing areas). Post-em e rgence applications are m o st likely to occur up to the end of August. There will be som e variability in tim ing based on geographical regions.

Use Classification: Most atrazine products are restricted use pesticides.

D. Estimated Usage of Pesticide

This section sum m a rizes the best estim ates of available pesticide usage inform ation for

atrazine from 1990 to 1997. A full listing of all uses of atrazine, with the corresponding use and usage data for each site, has been com p leted and is in the January 10, 2001 “Quantitative Usage Analysis for Atrazine” docum ent available in the public docket and on the internet. The data, reported on an aggregate and site basis, reflect annual fluctuations in use patterns as well as the variability in using data f r om various inf o rm ation sources.

Estim ates for total annual dom estic use of atrazine averages approxim a tely 76.5 m illion pounds of active ingredient. Crops with the highe st weighted average percent crop treated are corn (75%), sugarcane (76%), sorghum (58.5%), sweet corn (processed) (58%) and sweet corn (fresh) (49%). In term s of pounds applied, corn (83%), sorghum (10%), and sugarcane (3%) account for the greatest use. Less than 2% of atrazine is believed to be applied in forestry, turf or other non-agricultural uses.

Table 1. Atraz i ne Estimated Usage for Representative Sites

13Crop Pounds Active Ing redient Applied

(000) (Wt. Avg.) 1 Estimated

Maximum % Crop Treated Weighted Average Percent Crop

Treated

Food Crops

Sweet C o rn, Fresh 160 59.9 49.5

Sweet C o rn, Processed 250 64.6 58.2

Sorghum 7,790 73.7 58.5

C o rn 63,800 84.0 75.0

W i nt er W h eat 300 1.1 0 .6

Sugar C a ne 2550 95 76.0

Non-Food Crops

Hay 150 0.7 0 .4

Past ure 4 6 0 .1 0.0

Sum m e r Fallow 8 0.1 0 .1

W oody Ornam e nt al s 140 na na

Forest ry 48 na na

Turf - Lawn C a re Operat ors 600 na na

Sod 160 na na

Gol f C ourses 7 8 n a n a

1 W e ighted Average is based on data fo r 1990-1997; the m o st recent years and m o re reliable data are weighted m o re

heavi l y . B a sed on USDA/ NASS and EPA propri e t a ry dat a

.

14III. Summary of Atraz i ne Risk Assessments

The following is a sum m a ry of EPA’s revised hum an health and ecological risk findings

and conclusions for the triazine herbicide atrazine. These findings and conclusions are fully presented in the following docum ents, available on EPA’s web page at www.epa.gov/pesticides and in the public docket:

• R eregistration Eligibility Science Chapter f o r Atrazine - Environm ental Fate and Effects Chapter (April 22, 2002);

• A trazine: HED’s Revised Hum a n Health Risk Assessm ent for the Reregistration Eligibility Decision (April 16, 2002);

• A ddendum and corrections to Occupational and Residential Exposure Chapter for Atrazine (May 23, 2002); and

• A trazine: Addendum to Revised Hum a n Health Risk Assessm ent for the Reregistration Eligibility Decision (RED) (January 31, 2003).

These risk assessm ents for atrazine were pr esented at a Technical Briefing held on April 16, 2002, and followed by an opportunity for public com m e nt on risk m a nagem e nt. The risk

assessm ents presented here form the basis of the Agency’s risk m a nagem e nt decision for atrazine only; the Agency m u st consider a cum u lative assessm ent of the risks of all triazine pesticides before any final decisions can be m a de.

A. Human Health Risk Assessment

EPA issued its prelim inary hum an health risk assessm ent f o r atrazine and its m e tabolites on February 14, 2001 (Phase 3 of the TRAC process). In response to com m e nts and studies

subm itted during Phase 3, the risk assessm ent was updated and refined, and released on May 6,

2002. In addition, any new Agency policies were incorporated as appropriate. Major revisions

to the hum an health risk assessm ent are listed below:

• R evisions to the occupational and residential risk assessm ents to incorporate m o re recent data and inform ation received in the response to com m e nts.

• R evisions to the dietary drinking water risk assessm ent to include additional

m onitoring data received from the registrant.

• A decision not to require tolerances for hydroxyatrazine.

Exposure scenarios considered in the hum an health assessm ent are acute, interm ediateterm , and chronic dietary exposure through food pl us drinking water; short-term residential exposures from residential applications of atr azine; acute, chronic, and short-term aggregate exposure from all sources (food, drinking water, and residential); and short and interm ediateterm occupational exposures.

In the risk assessm ents presented in this docum ent, the toxicity of atrazine and its

chlorinated m e tabolites are considered to be equivalent; theref ore, the risks associated with

15exposure to atrazine and its chlorinated m e tabolites are presented together. The toxicity of the

m e tabolite hydroxyatrazine is considered to be inde pendent of the effects of atrazine; thus, the

risks from exposure to hydroxyatrazine are presented independently.

1. Dietary Risk From Food

a. Toxicity and Carcinogenicity

1) Atraz i ne and the Chlorinated Metabolites

The atrazine toxicity database is extensive. The Agency has reviewed these toxicity studies and has a high degree of conf idence in the scientif ic quality of the toxicity studies

conducted with atrazine. Special studies exam ining the toxicology of atrazine have been perform e d by the registrant in addition to th e required guideline studies. Additionally, EPA' s National Health and Environm ental Effects Laboratory (NHEERL) has perform e d studies investigating atrazine' s neuroendocrine m ode of action and related reproductive and developm ental effects.

For the purposes of this risk assessm ent, the toxicity of atrazine’s chlorotriazine

m e tabolites is considered to be equivalent to that of parent atrazine and exposure to those

m e tabolites m a y occur. Theref ore, the chlorotriazine m e tabolites are included in the atrazine

hum an health risk assessm ent.

In accordance with the 1999 Interim Guidelines for Carcinogen Risk Assessm ent, EPA’s

Cancer Assessm ent Review Com m ittee (CARC) cl assified atrazine as “not likely to be carcinogenic to hum ans”. As sum m a rized by the FIFRA Scientific Panel (SAP), “there are considerable differences between hypothalam i c-pituitary-ovarian function in rats and hum ans, and the effects of aging on the function of the ax is also is quite dissim ilar. Theref ore, it is unlikely that the m echanism by which atrazine induces m a m m a ry gland tum o rs in fem a le SD rats could be operational in hum ans. Nevertheless, it is not unreasonable to expect that atrazine

m i ght cause adverse effects on hypothalam i c-pituitary function in hum ans” (SAP, 2000). Although the cancer m ode of action m a y not be operative in hum ans, the SAP further to state

that the sam e endocrine perturbations that induce tum o rs also appear to play a role in at least

som e reproductive developm ental effects (not associated with reproductive aging) which m a y be

relevant to hum ans. The Agency also concluded that the cancer m ode of action is not relevant to

hum ans. Consequently, a quantitative cancer risk assessm ent was not conducted for atrazine. However, EPA agreed in the August 2002 am endm ent to the Consent Decree in NRDC v. Whitman to present to the SAP data concerning atrazine exposure and prostrate or other cancers

in hum ans that had been received by EPA after the May 2002 risk assessm ent but prior to February 28, 2003. Any risks identified will be addressed in the revised Atrazine IRED to be issued by October 31, 2003.

As indicated above, the cascade of events triggered by atrazine leading to m a m m a ry gland tum o rs in fem a le SD rats are not expected to occur in hum ans given the species difference

16in reproductive aging. However, the potential for disruption of the hypothalam i c pituitary axis and consequent attenuation of the LH surge leading to other health consequences not associated with reproductive aging (e.g., delay in pubertal de velopm ent) can not be dism issed. Thus, EPA

has determ ined that the triazine pesticides (with a com m on m echanism group of atrazine, propazine, sim azine and their chlorom e tabolites) have com m on m echanism of suppression of LH surge and consequent developm ental and reproductive effects. It is expected that EPA will

com p lete a prelim inary cum u lative risk assessm ent in the winter of 2005; this is contingent on

com p letion of the IREDs for the individual chem icals.

2) Hydroxyatraz i ne

Atrazine is m e tabolized to hydroxyatrazine by plants and bacteria. Anim als do not

m e tabolize atrazine to hydroxyatrazine; however, they m a y receive hydroxyatrazine in their diets through forages and fodders.

A lim ited toxicology database for hydroxyatrazine com pounds is available. Hydroxyatrazine appears to be less acutely toxic than the parent atrazine. The only effects seen in any of the subm itted studies that m a y be attributable to a single dose were developm ental alterations in the developm ental rat study. The developm ental alterations seen in this study were seen only at the high dose, were few in num ber, and were deem ed to be not of toxicological significance. Thus, the Agency did not sel ect an acute endpoint for hydroxyatrazine, and concludes that no toxicologically significant endpoint to represent a single exposure can be found in the toxicology database for hydroxyatrazi ne. Hydroxyatrazine has not been classified as to its carcinogenic potential by the Agency.

Further details on the toxicity of atrazine and its chlorinated and hydroxy m e tabolites can be found in the April 16, 2002, Revised Hum a n Health Risk Assessm ent; the January 31, 2002,

Addendum to the Revised Hum a n Health Risk Assessm ent; and all supporting docum ents. An

overview of the studies and saf e ty f actors used f o r the dietary risk assessm ent is outlined in

Table 2.

b. FQPA Safety Factor

The FQPA safety factor is intended to provide up to an additional 10-fold safety factor (10X) to account for potential pre- and post-natal toxicity and the com p leteness of the data with respect to exposure and toxicity to infants and children.

1) Atraz i ne and the Chlorinated Metabolites

The FQPA Safety Factor of 10x was retained for atrazine and its chlorinated m e tabolites to protect the safety of infants and children in assessing risk from dietary (food and drinking water) exposures.

The Agency concluded that, as to dietary risk, the default 10x FQPA safety factor is

17required because of the absence of reliable eviden ce showing that a different safety factor would be protective of infants and children. The principal grounds for this conclusion are:

• r esidual concerns for the effects of the neuroendocrine m ode of action described for atrazine on the developm ent of the young. These concerns could not be accounted for in

the determ ination of toxicity endpoints and traditional uncertainty factors to be used in

risk assessm ent; and,

• r esidual concerns with regard to the drinking water exposure assessm ent. The various

water m onitoring data sources that exist f o r atrazine and its chlorinated m e tabolites indicate that exposure via drinking water sources is high in som e of the system s that have

been m onitored. In addition, widespread low levels are com m only detected. Lim itations in the extent, frequency, and com pounds tested for in the m onitoring data raise significant uncertainties regarding the level of exposure to atrazine and its m e tabolites.

The 10X FQPA safety factor is being applied across all aggregate risk assessm ents based

on estim ated dietary exposures for all populations considered in these risk assessm ents.

For residential exposures, the FQPA safety factor was reduced to 3x. This is considered adequate to protect the safety of infants and children in assessing residential exposure and risks because the exposure concerns for drinking water included in the 10x FQPA safety factor for dietary exposure do not apply to residential exposure scenarios, although the concerns for the

effect of the neuroendocrine m ode of action on the developm ent of the young rem a in. The

assum p tions inherent to the Agency’s residential risk estim ates based on screening-level procedures are conservative and protective. The 3x FQPA safety factor is being applied across all aggregate risk assessm ents based on estim ated residential exposures for all populations

considered in these risk assessm ents.

2) Hydroxyatraz i ne

The FQPA Safety Factor of 10x was rem oved for atrazine’s hydroxym etabolites for the following reasons:

• T here was no evidence of increased susceptibility in the prenatal developm ental toxicity study in rats with hydroxyatrazine;

• T here is no evidence of neurotoxicity f r om the subm itted toxicity studies;

• The neuroendocrine effects described for atrazine are postulated to be part of a cancer

m ode of action for atrazine. Because hydroxyatrazine is non-carcinogenic, the current

belief is that the neuroendocrine effects desc ribed for atrazine are not occurring following hydroxyatrazine exposure;

• T he dietary and non-dietary exposure assessm ents do not underestim ate the potential

18exposures for infants and children; and

• T he drinking water exposure concerns expressed for atrazine and the chlorinated

m e tabolites do not apply to hydroxyatrazine, given its dissim ilar toxicological profile and

environm ental fate properties that indicate that hydroxyatrazine is less m obile in soil/water system s.

c. Population Adjusted Dose

The population adjusted dose (or PAD) is a term that characterizes the dietary risk of a

chem ical. The PAD reflects the Reference Dose (RfD), either acute or chronic, that has been adjusted to account for the FQPA safety factor (i.e., RfD/FQPA safety factor). The RfD is calculated by taking the no observed adverse eff ect level (NOAEL) from an appropriate study and dividing it by an uncertainty factor (i.e ., NOAEL/UF). Acute and chronic PADs are equivalent to the acute and chronic RfDs divided by 10, respectively. A risk estim ate that is less than 100% of the acute PAD (aPAD) or chronic PAD (cPAD) does not exceed the Agency’s

level of concern. In the case of atrazine, the FQ PA safety factor of 10x was retained for dietary exposures; therefore, the RfD is ten tim es greater than the PAD. The PADs are presented in Tables 2 and 3 below for atrazine and hydroxyatrazine, respectively.

Table 2. Summary of Toxicological Endpoints and Other Factors Used in the Dietary

Risk Assessment of Atraz i ne and Its Chlorinated Metabolites

Ex po sure Scenario Dose (mg/ kg/ d ay) UF FQPA

SF Endpoint S tudy

Acute Dietary (fem a les 13

t o 50 y r s ol d) NOAEL= 10

LOAEL = 70 100 10 Del a y e d ossi fi cat i on of cert a i n crani a l bones i n fet u ses, decreased body wei ght gai n i n adul t Devel opm ent a l

t oxi ci t y st udy i n rat
& rabbi t (wei ght of

evidence from four

st udi es)

Acute RfD = 0.1 m g / kg/ day

Acute PAD = 0.01 m g / kg/ day

In term ed iate

and

C h roni c NOAEL = 1.8

LOAEL = 3.65 100 10 At t e nuat i on of pre-ovul at ory l u t e ni zi ng horm one (LH) surge, as a

bi om arker i ndi cat i v e of hy pot hal a m i c funct i on di srupt i on Si x-m ont h LH surge

st udy -R at

Chronic RfD = 0.018 m g / kg/ day

Chronic PAD = 0.0018 m g / kg/ day

UF = Uncertainty Factor (100 is the resu lt of a 10x for interspecies variability and 10x for intraspecies extrapolation); SF=Sa fety Factor; PAD = Population Adjusted Dose

19Table 3. Summary of Toxicological Endpoints and Other Factors Used in the Human Dietary (Food) Risk Assessment of Hydroxyatraz i ne, a Metabolite of Atraz i ne

Ex po sure Scenario Dose (mg/ kg/ d ay) UF 1 FQPA

SF 1 Endpoint S tudy

Acute Dietary None sel ect ed na na An appropri a t e endpoi nt

at t r i but abl e t o a si ngl e dose was

not i d ent i f i e d (no t oxi c effect seen) None selected

Acute RfD = No t Estab lish e d

C h roni c Dietary NOAEL = 1.0

LOAEL = 7.75 100 1 Hi st opat hol ogi cal l e si ons of t h e ki dney s Com b ined chronic

to x i city/

carci nogeni ci t y -R at

Chronic RfD = 0.01

Chronic PAD = 0.01 m g / kg/ day

UF = Uncertainty Factor (100 is the resu lt of a 10x for interspecies variability and 10x for intraspecies extrapolation); SF=Sa fety Factor; PAD = Population Adjusted Dose

d. Exposure Assumptions

The Agency conducts dietary (food) risk assessm ents using the Dietary Exposure Evaluation Model (DEEM TM ). DEEM incorporates consum ption data generated in USDA’s Continuing Survey of Food Intake by Individuals (CSFII), 1989-92. For the assessm ent of dietary exposure to residues of atrazine, m on itoring data generated through the USDA Pesticide Data Program (PDP) and through the Food and Drug Adm i nistration (FDA) Surveillance Monitoring Program were used for wheat grain. Anticipated residue values from crop residue

field trial studies and inform ation from m e tabolis m studies were used for m o st crops. For guava,

tolerance level residues were used.

For acute probabilistic dietary (food) risk assessm ents, the entire distribution of singleday food consum ption events is com b ined with a distribution of residues to obtain a distribution of exposure in m g /kg/day. Chronic dietary (food) risk assessm ents use the three day average of

consum ption for each subpopulation com b ined with residues in com m odities to determ ine average exposure in m g /kg/day.

e. Food Risk Characteriz a tion

Generally, a dietary (food) risk estim ate that is less than 100% of the acute or chronic PAD does not exceed the Agency’s risk concern. Acute and chronic risk estim ates from exposures to food associated with the use of atrazine did not exceed the Agency’s level of

concern.

201) Atraz i ne and Its Chlorinated Metabolites

The percent acute PAD value for the relevant population subgroup considered under the

acute risk assessm ent, fem a les 13 to 50 years old, is less than 1 at the 99.9th percentile of

exposure. The percent chronic PAD values for all exposed population subgroups were less than 1, as well. These estim ates of risk based on one-day and long-term exposures to atrazine and its

chlorinated m e tabolites from residues on food alone are below the Agency’s level of concern.

2) Hydroxyatraz i ne

No acute toxicological endpoint was identified for hydroxyatrazine; therefore, an acute

risk assessm ent for hydroxyatrazine and the hydroxylated m e tabolites was not conducted. The percent chronic PAD values were less than 1 for all population subgroups considered in the risk

assessm ent. Therefore, estim ates of risk based on long-term exposures to hydroxyatrazine from residues on food alone are below the Agency’s level of concern.

2. Dietary Risk from Drinking Water

Exposure to pesticides from drinking water can occur through residues in ground water

and surface water. In the assessm ent for atrazine, EPA considers both acute (one day),

interm ediate-term (seasonal), and chronic (annual) exposures to residues in drinking water risks

and uses actual m onitoring data to characterize those risks.

Drinking water risk from the application of atrazine is assessed based on exposures to

com b ined residues of atrazine and the chlorinated m e tabolites. These are the only atrazinerelated com pounds expected to occur in drinking water in significant quantities. Extensive

m onitoring data are available for atrazine parent in finished drinking water, and som e m onitoring

data are available f o r the chlorinated m e tabolites. This m onitoring data is the basis f o r the Agency’s drinking water risk assessm ent. To estim ate the levels of chlorinated m e tabolites in

areas where m onitoring data is not available f o r those m e tabolites, the Agency developed a

m odel based on the available m onitoring data which the Agency believes provides a reasonable

estim ate of the levels of the chlorinated m e tabolites that could be expected in drinking water.

A qualitative assessm ent of exposure to the hydroxy m e tabolites of atrazine in drinking water has been conducted by the Agency. Exposure to these com pounds is expected to be significantly less than exposure to atrazine and the chlorinated m e tabolites based on the

characteristics of these m e tabolites. Therefore, the Agency has not included the hydroxy

m e tabolites in its quantitative risk assessm ent f o r drinking water

Risk estim ates for exposures to residues of atrazine and its chlorinated m e tabolites in drinking water are provided for populations r eceiving their drinking water from com m unity

water system s (CW S ) using surface water, CW S using groundwater; and individual rural wells

located in atrazine use areas. Exposure assessm ents were conducted for about 33 percent of the

CW S using surface water in the United States, serving approxim a tely 65 m illion people in 31

atrazine use states. These CW S represent a bout 99% of atrazine use. The Agency uses

21m onitoring data for finished (i.e., treated) drinking water in the assessm ent presented here.

The Agency initially conducted a determ inistic (screening-level) drinking water risk

assessm ent f o r atrazine and its chlorinated m e tabolites. The initial assessm ent identif ied specif ic

CW S and rural wells as having concentrations of atrazine and its chlorinated m e tabolites above the Agency’s level of concern. The CW S of concern were assessed probabilistically to ref i ne the

risk estim ates; insuf f i cient data were available to ref i ne the risk estim ates f o r rural wells.

a. Drinking Water Levels of Comparison (DWLOC)

To determ ine the m a xim u m allowable contribution of water containing pesticide residues

perm itted in the diet, EPA first looks at how m u ch of the overall allowable risk is contributed by food (and if appropriate, residential uses) then determ ines a “drinking water level of

com p arison” (DW L OC) to determ ine whether m odeled or m onitoring levels exceed this level. The Agency uses the DW LOC as a surrogate to capture risk associated with exposure from pesticides in drinking water. The DW LOC is the m a xim u m concentration in drinking water that, when considered together with dietary (food) exposure, does not exceed a level of concern.

Calculated DW LOCs are presented in Table 4 below.

The results of the Agency’s drinking water analysis are sum m a rized here. Details of this analysis are found in the HED Hum a n Health Risk Assessm ent dated April 16, 2002, the EFED

Environm ental Risk Assessm ent dated April 20, 2002.

Table 4. Summary of Low e st DWLOC Values for Atraz i ne and Its Chlorinated

Metabolites

Population Subgroup DWLOC (ppb)

Acute (One Day)

Ex po sure Intermediate (Seasonal) and Chronic (Annual) Exposure

General Popul at i o n not avai l a bl e 6 8

Infant s < 1 y ear ol d not avai l a bl e 12.5

C h i l d ren 1 t o 6 not avai l a bl e 2 3

C h i l d ren 7 t o 12 not avai l a bl e 5 3

Fem a l e s 13 t o 50 298 60

M a l e s 13 t o 19 not avai l a bl e 6 8

M a l e s 20 and over not avai l a bl e 6 8

Seni ors not avai l a bl e 6 8

1) Community Water Systems (CWS) Using Surface

22Water

a) Acute Risk

Based on the Agency’s determ inistic assessm ent, the m easured m a xim u m one-day

concentrations of atrazine plus estim ates of the chlorinated m e tabolites in drinking water do not exceed the Agency’s level of concern for acute effects, regardless of source, for any relevant population subgroup.

Based on the Agency’s screening-level determ inistic assessm ent, one-day concentrations

less than the DW LOC of 298 ppb do not exceed the level of concern for acute effects. The

m a xim u m m easured concentration of atrazine and its chlorinated m e tabolites in any CW S

m onitoring for atrazine from 1993 to 1998 was 89 ppb.

b) Intermediate-Term (Seasonal) and Chronic (Annual) Risk

As stated previously, the drinking water concerns expressed for atrazine and its

chlorinated m e tabolites do not apply to hydroxyatrazine because of its toxicology profile and

environm ental fate profile.

Under the Agency’s screening-level assessm ent for interm ediate-term and chronic exposures to atrazine and its chlorinated m e tabolites, 34 out of the 3670 CW S assessed were above the Agency’s level of concern based on a com p arison of average seasonal concentrations

to the chronic infant DW LOC of 12.5 ppb. These CW S were identified with quarterly average concentrations of chlorotriazines above levels of concern for infants in one, two, or three years

between 1993 and 2001. In addition, several of the 34 had annual average concentrations above the levels of concern for children 1 to 6 years old and adults.

A probabilistic exposure assessm ent was conducted for 39 CW S, m o st of which were identified as being of concern under the screening-level assessm ent, as listed above. Risk

estim ates based on a probabilistic exposure assessm ent that estim ated 90-day average exposures

to atrazine and the chlorinated m e tabolites indicate that 34 CW S have seasonal concentrations that exceed levels of concern for infants at the 99.9th percentile of exposure.

In total, 34 CW S serving ~230,000 to 240,000 people had 90-day average exposures that exceeded levels of concern for infants in one, two, three, or four years between 1993 and 2001.

Risk estim ates for these CW S ranged from 100% to 670% of the chronic PAD for infants at the 99.9th percentile of exposure, and several exceeded levels of concern for children 1 to 6 years

old and adults as well. The CW S identified and the cPADs for these system s are listed in Table

5 below.

Table 5. Risk Estimates for High Seasonal Ex posures to Atraz i ne in Finished Drinking

Water at the 99.9 th Percentile of Exposure* (CalandexTM)

23Community Water System (City/State) Infant

% cPAD Children 1 - 6

% cPAD Adult

% cPAD

Chariton, IA 235 <100 <100

Sorento, IL 183 <100 <100

Flora, IL 211 <100 <100

W. Salem, IL 189 100 <100

Farina, IL 189 <100 <100

White Hall, IL 278 117 <100

Carlinville, IL 128 <100 <100

Gillespie, IL 550 222 172

Hettick, IL 544 222 172

Shipman, IL <100 <100 <100

Palmy r a-Modesto, IL 350 155 111

N. Otter Twp ADGPTV, IL 189 <100 <100

Kinmundy , IL 150 <100 <100

Salem, IL 528 267 200

Centralia, IL 255 100 <100

Hillsboro, IL 272 117 <100

Louisville, IL 344 122 <100

North Vernon, IN 200 117 <100

Omaha, IL 250 111 <100

Holland, IN 244 128 <100

Batesville, IN 261 111 <100

Scottsburg, IN 267 150 105

Lewisburg, KY 317 128 <100

Marion, KY 317 128 <100

Iberville, LA 261 117 <100

Dearborn, MO 555 228 155

Bucklin, MO 250 100 <100

Vandalia, MO 189 105 <100

Sardinia, OH 667 305 205

Delaware, OH 155 <100 <100

24Community Water System (City/State) Infant

% cPAD Children 1 - 6

% cPAD Adult

% cPAD

Clermont County

, OH 144 <100 <100

W illiam s burg, OH 289 122 <100

Mt. Orab, OH 200 <100 <100

Newark, OH 111 <100 <100

The Agency notes that the Shipm a n reservoir no longer serves as a drinking water source; in 1999 the town of Shipm a n was switched to an alternative source of drinking water. The drinking water source at W h ite Hall was switched from surface water to groundwater in 1997. It is the Agency’s understanding that Hettick, IL is also in the process of defining a new source for their drinking water needs and will close down the Hettick reservoir in the next couple of years.

The seasonal pulses of atrazine and the chlorinated m e tabolites detected in m onitoring data that resulted in exposures above the Agency’s level of concern spanned from several weeks

to several m onths. Typically, for the year with exposures of concern, pulses lasted from early spring through the sum m e r and into the fall, and som e CW S had high pulses alm o st all year long. The higher concentrations occurring in the spring and early sum m e r influence the 90-day average concentrations all year long.

2) Groundw ater

Risk estim ates based on screening-level assessm ents for 14,500 CW S using groundwater (~33 percent of groundwater CW S in the U.S.) do not exceed the Agency’s level of concern for

acute or chronic effects.

Data to estim ate concentrations of the chlorinated m e tabolites of atrazine in these CW S using groundwater in 21 m a jor atrazine use states have been developed. The highest

concentration of atrazine and the chlorinated m e tabolites m easured in any CW S in the data set was ~11 ppb. The 99 th percentile concentration value f o r chlorotriazines in CW S with prior detections of atrazine was 1.9 ppb. Both the m a xim u m m easured value and the 99 th percentile

value are less than the acute DW LOC of 298 ppb, and do not exceed the Agency’s level of

concern for acute effects.

The 50 th percentile concentration value was 0.180 ppb for CW S with prior detections.

The m ean concentration value at the 95 percent upper confidence bound was 0.55 ppb for CW S with prior detections. Both are less than the lowest interm ediate-term to chronic DW LOC of

12.5 ppb, and do not exceed the Agency’s level of concern for chronic effects.

The Agency believes that CW S using groundwater are not im pacted as heavily by

atrazine use as CW S using surface water.

3) Domestic Rural Wells

25Approxim a tely 10% of the U.S. population recei ves their drinking water from rural wells, cisterns or springs. These sources of drinki ng water are not regulated under the SDW A

. Acute exposures to atrazine and the chlorinated m e tabolites in drinking water from rural wells do not exceed the Agency’s level of concern. The m a xim u m m easured concentration of atrazine plus

the chlorinated m e tabolites in the rural drinking water wells in atrazine use areas m onitored by the registrant was 18 ppb; m u ch less than the acute DW LOC (fem ales 13 to 50) of 298 ppb. In addition, chronic exposures of adult populations using rural wells for drinking water do not exceed the Agency’s level of concern.

However, the Agency has som e concerns for chronic exposures of infants and children drawing drinking water from rural wells located directly in atrazine use areas, i.e., adjacent to

fields where atrazine was used. Eight wells out of 1505 wells m onitored had residues of atrazine

and the chlorinated m e tabolites approaching, equal to, or greater than the chronic DW LOC (infants <1 year old) of 12.5 ppb. The 1505 wells m onitored were selected based on their location in areas with high atrazine use. Of these, eight wells were resam p led in March 2001,

one sam p le per well. All sam p les showed concentrations of atrazine and the chlorinated

m e tabolites less than the DW LOC of 12.5 ppb.

Although the data indicate that levels are decreasing in these wells over tim e, the Agency continues to have uncertainty regarding subchronic and chronic exposures of infants using private rural wells in close proxim ity to atrazine use areas for the several reasons. It is difficult to interpret typical exposures in rural wells close to atrazine use areas based on two sam p les

taken m a ny years apart. There are approxim a tely 13 m illion drinking water wells in the U.S., thus, the rural well survey (1,505 wells) is inadequate to fully assess exposures to the entire U.S. population that uses rural wells for drinking water. And finally, lim ited sam p ling from the wells in the survey results in a high level of uncertainty regarding exposures to atrazine and the

chlorotriazine m e tabolites for the population using rural wells for drinking water.

2. Residential Risk

Atrazine is registered for use by hom eowners to control weeds in turf grass.

Hom e owners m i xing, loading, and applying atrazine products to their lawns m a y be exposed to atrazine through their skin and by inhaling dusts or sprays during application. Residential exposures are only applicable for those regions of the United States where atrazine is used on turf grass, generally the Southeast (including Florida).

Adults or children can also be exposed to atrazine after application has occurred through contact with treated lawns or other turf areas (i .e., golf courses). In this instance, inhalation exposures are not expected; however, post-application derm al exposures for hom eowners and children (yard work, walking, playing, crawling) and incidental oral exposure for toddlers are possible. Exposure data are not available on atrazine’s chlorinated m e tabolites and hydroxy

m e tabolites; however, residues of the chlorinated m e tabolites and hydroxy m e tabolites are not expected to occur on the surfaces of plants. Therefore, any residential exposure to these

m e tabolites would be m i nim a l, and risks were not assessed.

26The Agency recognizes that there m a y be concerns for the potential for children’s exposure in the hom e as a result of agricultural uses of atrazine. Environm ental concentrations

of atrazine in hom es m a y result from spray drif t, track-in, or from redistribution of residues brought hom e on the farm worker’s clothing. Potential routes of exposure for children m a y include incidental ingestion and derm al contact with residues on carpets/hard surfaces. Studies are currently being pilot-tested that will look for sources of m a jor pesticide exposure (including exposure to atrazine) and will attem p t to quantify these exposures.

Risk for all of the potentially exposed populations is m easured by a Margin of Exposure (MOE). A MOE determ ines how close the am ount of residue that individuals are exposed to

com e to a No Observed Adverse Effect Level (NOAEL), whether exposures are from the use of a pesticide or from pesticide residues after application. For atrazine, MOEs greater than 300 (10 interspecies uncertainty x 10 intraspecies variability x 3 FQPA) do not exceed the Agency’s

level of concern.

a. Toxicity

The toxicity of atrazine is integral to assessing the residential risk. The toxicological endpoints and other factors used in the residential risk assessm ent for atrazine are described

below and sum m a rized in Table 6.

As m e ntioned earlier, the FQPA safety factor for residential exposures was reduced to 3x. This is considered adequate to protect the safety of infants and children in assessing residential exposure and risks because the uncertainties relating to drinking water exposure and the existing

m onitoring data included in the 10x FQPA safety factor for dietary exposure do not apply to residential exposure scenarios. Concerns for the effect of the neuroendocrine m ode of action on the developm ent of the young rem a in. The assum p tions inherent to the Agency’s residential risk

estim ates based on screening-level procedures are conservative and protective. The 3x FQPA safety factor is being applied across all aggregate risk assessm ents based on estim ated residential exposures for all populations considered in these risk assessm ents.

Table 6. Summary of Toxicological Endpoints and Other Factors Used in the Atraz i ne Residential Human Health Risk Assessment

Ex po sure Scenario Dose (mg/ kg/ d ay) UF 1 FQPA Safety

Factor Endpoint S tudy

Oral,

Short

- Term NOAEL= 6.25

LOAEL = 12.5 100 3 Del a y e d preput i a l separat i on i n

m a l e offspri ng aft e r 30 day s of

dosi ng. Pubert al assay (30­ day) NHEERL

p u b lish e d literatu re

Oral,

In term ed iateTerm NOAEL = 1.8

LOAEL = 3.65 100 3 At t e nuat i on of pre-ovul at ory l u t e ni zi ng horm one (LH) surge, as a

bi om arker i ndi cat i v e of hy pot hal a m i c funct i on di srupt i on Si x-m ont h LH surge- Rat

27Table 6. Summary of Toxicological Endpoints and Other Factors Used in the Atraz i ne Residential Human Health Risk Assessment

Ex po sure Scenario Dose (mg/ kg/ d ay) UF 1 FQPA Safety

Factor Endpoint S tudy

Derm al,

Short

- Term a NOAEL= 6.25

LOAEL = 12.5 100 3 Del a y e d preput i a l separat i on i n

m a l e offspri ng aft e r 30 day s of

dosi ng. Use of t h e derm al

penet r at i on fact or y i el ds a dose of

104 m g / kg/ day

. Pubert al assay (30­ day) NHEERL

p u b lish e d literatu re

Derm al, At t e nuat i on of pre-ovul at ory Si x-m ont h LH

In term ed iateand Long-Term b NOAEL= 1.8

LOAEL = 3.65 100 3 l u t e ni zi ng horm one (LH) surge, as a

bi om arker i ndi cat i v e of hy pot hal a m i c funct i on di srupt i on surge- Rat

Inhal a t i on, Short

- Term c NOAEL= 6.25

LOAEL = 12.5 100 3 Del a y e d preput i a l separat i on i n

m a l e offspri ng aft e r 30 day s of

dosi ng. Pubert al assay (30­ day) NHEERL

p u b lish e d literatu re

Inhal a t i on, At t e nuat i on of pre-ovul at ory Si x-m ont h LH

In term ed iate

and NOAEL= 1.8

LOAEL = 3.65 100 3 l u t e ni zi ng horm one (LH) surge, as a

bi om arker i ndi cat i v e of surge-Rat

Long-Term c hy pot hal a m i c funct i on di srupt i o n

1 UF = Uncertainty Factor (100 is the re sult of a 10x for interspecies variability and 10x for intraspecies extrapolation)

a = The NOAEL of 6.25 m g /kg/day is m u ltiplie d by a 3.6 derm al penetration factor.

b = 6% der m al absor p tion factor for r oute- to- r oute extr apolation.

c = 100% absor p tion factor for r oute- to- r oute extr apolation.

Residential = A M O E of 300 is r e quir e d and includes the 3x FQPA Safety Factor

b. Exposure Assumptions

Residential exposures to atrazine are expected to be short-term in duration (1 to 30 days), based on label directions that specify no m o re than two applications of atrazine to hom e lawns. Exposures greater than 30 days are not expected because no currently registered residential use products would result in exposures of this duration due to the use pattern and turf residue dissipation data on atrazine.

Chem ical-specific exposure data, includi ng a Turf Transferable Residue study on atrazine, and data on residential handlers applyi ng granular and liquid f o rm ulations subm itted by the Outdoor Residential Exposure Task Force (ORETF) were used to assess the exposure to atrazine as a result of residential application. In addition, analyses were perform e d using the unit exposure values in the Pesticide Handlers Exposure Database (PHED), Version 1.1 (August 1998) and using standard assum p tions (average body weight, work day, daily areas treated,

volum e of pesticide used, etc.).

The quality of the data and exposure factors represents the best sources of data currently

28available to the Agency for com p leting these kinds of assessm ents. For exam ple, if appropriate

chem ical-specific exposure data are available for atrazine, those data are used instead of the

m o re generic PHED data. The quality of the data used for each scenario assessed, standard procedures, and any assum p tions m a de are further discussed in the April 16, 2002, Revised

Hum a n Health Risk Assessm ent; the August 2002 Revised Occupational and Residential Risk

Assessm ent; and the January 31, 2003, Addendum to the Revised Hum a n Health Risk

Assessm ent available in the public docket and online.

Anticipated use patterns and application m e thods, range of application rates, and area of lawn treated per day were derived directly from current atrazine labels for residential products. Application rates specified on atrazine labels for residential uses range up to 2 pounds of active ingredient per acre on residential turf.

The Agency also considered exposure to adults or children entering or playing on treated lawns or entering hom es after application of atrazine products (post-application exposure). These activities are expected to result in short-term exposure (1 to 30 days), based on atrazine turf residue dissipation data and atrazine’s residential use pattern. These data show that atrazine has a half-life on turf of up to 5 days after sp raying or 9 days after granular application, and requires several weeks to dissipate. However, the Agency does not expect exposures greater than 30 days, even considering the slow dissipation rates, because the label prohibits application

m o re than twice per year.

Residential post-application exposure assessm ents assum e d residents wear the following attire: short sleeved shirt, short pants, shoes and socks, and no gloves.

c. Residential Applicator Risk

The anticipated use patterns and current labeling for atrazine hom eowner products

indicate 5 m a jor exposure scenarios for residential applicators, as follows:

(1) m ixing/loading/applying liquid form ulations using a backpack sprayer, (2) m ixing/loading/applying liquid form ulations for application with a low pressure handwand, (3) m ixing/loading/applying liquid form ulations for hose-end sprayer, (4) l oading/applying granular form ulati ons with a push type spreader, and (5) l oading/applying granular form ulations with a bellygrinder.

The Agency does not believe the addition of personal protective equipm ent (PPE) to residential handlers (as used for assessing occupational handler risk) is appropriate for

hom eowner handler exposure assessm ents. Hom e owners often lack access to PPE and do not possess expertise in the proper use of PPE. As a result, hom eowner handler assessm ents are

com p leted using a single scenario based on the use of short-sleeved shirts and short pants,

com m on hom eowner attire during the pesticide application season. In addition, as m e ntioned above, only short-term exposures were assessed, as the Agency does not believe hom eowners who apply atrazine will be exposed for m o re than a few consecutive days.

29All of the residential handler exposure scenar ios considered in the risk assessm ent, with the exception of the scenario for application of granular form ulations via a bellygrinder as a broadcast application, were below the Agency’s level of concern (MOEs > 300). MOEs

calculated for each hom eowner handler scenario are presented in Table 7, as follows:

Table 7. Homeow ner Uses and Risk Concern s (combined dermal & inhalation MOEs)

Scenario Rate (lb a i/A) Short-Term MOE

(1) M i xi ng, l o adi ng, and appl y i ng l i qui d form ul at i ons vi a backpack

sprayer 2 28,000

(2) M i xi ng, l o adi ng, and appl y i ng l i qui d form ul at i ons vi a l o w pressure handwand 2 1 ,600

(3) M i xi ng, l o adi ng, and appl y i ng l i qui d form ul at i ons vi a hose-end

sprayer 2 640 a

(4) Loadi ng and appl y i ng granul ar form ul at i ons vi a push t y pe spreader 2 1 ,100 a

(5) Loadi ng and appl y i ng granul ar form ul at i ons vi a bel l y gri nder

2 65 (broadcast) 1,400 (spot

treatm e nt)

a C a l c ul at ed usi ng OR ETF Uni t Exposure Val u es

d. Post-Application Residential Risk

Atrazine can be used on hom e lawns, golf courses, and on other turf areas where exposure to adults and children m a y occur. Derm al exposure to atrazine m a y result from entering the treated area, perform i ng yard wo rk (e.g., m o wing), playing or perform i ng otherrecreational activities (e.g., golfing) on the treated areas. In addition, incidental oral postapplication exposure to children m a y occur from “hand-to-m outh” (i.e., ingestion of grass, soil and/or granular pellets; or hand-to-m outh cont act) exposure when reentering treated lawns.

The Agency does not expect post-application inhalation exposure to atrazine to occur

because of low chem ical vapor pressure and dilu tion of vapor outdoors. Thus, this exposure was

not assessed. Handler study data support this conclusion.

Representative turf reentry activities include, but are not lim ited to:

(1) A dults involved in a low exposure activity, such as golfing or walking on treated turf. (2) A dults m o wing or other m oderate contact activity, for 1-2 hours. (3) A dults involved in a high exposure activity, such as heavy yard work (doses sim ilar to occupational scenarios for cutting and harvesting sod)

. (4) C hildren involved in high exposure activities on turf.

The Agency has risk concerns for post-application residential exposures to children from

incidental oral contact. In children exposed to treated lawns after application of liquid atrazine

30form ulations, hand-to-m outh activities and com b ined oral exposures result in MOEs above the Agency’s level of concern. MOEs are 210 for hand-to-m outh activities and 200 for com b ined oral exposures. In addition, for children exposed to treated lawns after granular applications, the Agency has concerns for incidental ingestion of granules. The MOEs for this scenario range

from 16 to 110.

Table 8: Residential Short-Term Post-A pplication Risk Estimates from Atraz i ne Application to Law n s

Scenario Application

Rate (lb ai/A) MOE

Liquid G ranular

GA NC GA 1 FL 1

Adult

Derm al Turf C ont act 2 510 4300 1200

W a l k i ng, Gol f i n g 2 7400 62,000 17,000

Push M o wi ng Lawn 2 15,000 120,000 34,000

Child

Derm al Turf C ont act 2 310 2,600 690

Oral Hand t o M out h Act i v i t y 2 210 950

Turfgrass/Object

M out hi ng 2 3300

Ingest i on of Soi l 2 62,500

Co m b in ed 2 2 200 730

Ingest i on of Granul es 2 n / a 16-31 (1.5% ai ) 57-110 (0.42% ai )

1 The MOEs presented here represent non-irrigated turf. As these MOEs were acceptable, irrigated turf

M O Es, general l y hi gher t h an non-i rri gat e d, were not present e d.

2 Co m b in ed in clu d e s Han d

- to -m o u t h activ ity, tu rfg rass/o b j ect m out hi ng; and i ngest i on of soi l

. Ingest i on of granules is not included because this is considered an infrequent, episodic event.

Adults m a y reasonably be expected to perform m o re than one activity on treated lawns in a single day, but an eight-hour duration of exposur e is unlikely. Therefore, it is reasonable to aggregate the exposures from playing/gardeni ng (highest exposure rate), walking, and m o wing (lower exposure rate) for a single MOE. The MOE for all post-application adult exposures

com b ined is 460 and is above the Agency’s level of concern. It is also possible that an adult would apply herbicide spray to a lawn and then play on it or m o w it later that day. In such an event, the aggregated derm al MOE for the day would be slightly lower than the target 300 for that day (MOE=270), based on the liquid applica tion study values, but not based on the granular

residue data. However, this not very likely and is considered a high-end estim ate of exposure.

31It is likely that derm al and oral incidental exposures m a y occur in the sam e day for children playing on atrazine-treated lawn. It can be seen from the MOEs presented in Table 8

that the incidental hand-to-m outh (licking fingers) exposure estim ate constitutes m o st of this oral

exposure. The overall MOE of 200 is only slightly less than the MOE of 210 for the hand-tom outh estim ate. The individual derm al and oral routes of exposure each exceed the level of concern, and aggregating these estim ates results in an even lower MOE. Ingestion of granules is not aggregated because it is considered an infrequent, episodic event.

3. Aggregate Risk

Aggregate risk assessm ents have been conducted for acute, short-term , and interm ediateterm to chronic exposures to atrazine and the chlorinated m e tabolites. Aggregate risk

assessm ents look at the com b ined risk fromdietary exposure (food and drinking water) and nonoccupational (e.g., residential, golfers, etc...). The acute aggregate risk assessm ent com b ines exposures to atrazine and the chlorinated m e tabolites in food and drinking water. The short-term aggregate risk assessm ent com b ines exposures to atrazine and the chlorinated m e tabolites in food and drinking water with residential exposures to atrazine, per se , occurring between 1 and 30 days after use of atrazine products at hom e. The interm ediate-term and chronic aggregate risk

assessm ent com b ines exposures to atrazine and the chlorinated m e tabolites in food and drinking

water alone because interm ediate-term (30 days to several m onths) and chronic (several m onths

to lifetim e) exposure scenarios for the registered non-occupational uses of atrazine are not expected.

Although a risk assessm ent for exposures to atrazine' s hydroxylated m e tabolites in food was conducted, risk assessm ents aggregating exposures to atrazine' s hydroxylated m e tabolites in food, drinking water, and in residential settings were not. There is lim ited data on hydroxyatrazine in water, and exposure to the hydr oxy m e tabolites of atrazine in drinking water is not expected to be significant relative to the chlorinated m e tabolites. In addition, the Agency does not expect exposure to hydroxyatrazine from applications of atrazine to turf because hydroxyatrazine is form ed within plant tissues, not on plant surfaces.

a. Acute Aggregate Exposure and Risk Estimates

The aggregate risk assessm ent for acute exposures to atrazine and the chlorinated

m e tabolites com b ines high-end one-day exposures through food and drinking water alone. The Agency does not believe that high-end exposures through food, drinking water, and residential

use will all occur on the sam e day. Theref ore, acute aggregate risk estim ates are the sam e as those presented for acute drinking water risks. Exposure to atrazine from food sources and drinking water do not exceed the Agency’s level of concern for acute dietary risk for any relevant subgroup, as described previously in Section III.A.2.a.3.

b. Intermediate-Term and Chronic Aggregate Exposure and Risk

Estimates

The aggregate risk assessm ent for interm ediate-term and chronic exposures to atrazine

32and the chlorinated m e tabolites com b ines estim ates of high-end seasonal or long-term average exposures to atrazine in drinking water with l ong-term average exposures to atrazine in food.

Neither interm ediate-term nor long-term (chronic) exposures are expected to occur in the hom e from residential uses of atrazine. Therefore, interm ediate-term and chronic aggregate risk

estim ates are the sam e as those presented for interm ediate-term and chronic drinking water risks (see section III.A.2.a.3). Infants and children are potentially at risk from exposures to com b ined residues of atrazine plus its chlorinated m e tabolites from 34 CW S using surface water based on

available m onitoring data. Aggregate interm ediate-term and chronic exposures in CW S using groundwater are not of concern.

c. Short-Term Aggregate Exposure and Risk Estimates

Short-term estim ates of aggregate risk were calculated for adult applicators and children and adults exposed to residues of atrazine after application to hom e lawns. Short-term aggregate
risk estim ates that include residential exposures are only applicable for those regions of the United States where atrazine is used on turf grass (residential and golf courses), generally the Southeast (including Florida).

The theoretical upper lim it in drinking water for short-term exposures is referred to as a

short-term DW LOC and is based on exposure estim ates for adults and children from average residues of atrazine in food and exposure to high-end atrazine residues during application or

im m e diately after application of atrazine to lawn s. If the short-term DW LOC values are greater

than the m easured average concentrations for atrazine residues in surface water and groundwater, there is no concern for short-term a ggregate exposures to atrazine residues through food, drinking water, and non-occupational uses. M easured concentrations of atrazine residues in surface water and groundwater from m onitoring data (as presented earlier in this docum ent)

were com p ared to the calculated short-term DW LOCs.

1) Adult Handlers

Short-term estim ates of aggregate risk to adults applying atrazine products to the lawn and garden com b ines exposures through the derm al, dietary (food and drinking water), and

inhalation routes. These exposures have a com m on toxic effect, delayed puberty as a biom arker

for neuroendocrine effects.

Table 9 below presents the results of the Agency’s short-term aggregate risk assessm ent
for adult handlers of atrazine. Of the five exposure scenarios evaluated, only applications of granular form ulations of atrazine applied over 0.5 acres with a belly-grinder results in aggregate exposures that exceed the Agency’s level of concern.

Aggregate short-term DW LOC values are presented for the five adult handler scenarios

in Table 9. The first four DW LOCs presented are greater than the m easured m a xim u m weekly concentration of 89 ppb atrazine and the chlorotri azines in finished drinking water; thus, these scenarios are not of concern to the Agency. A DW LOC of 0 is assigned for adults applying via belly grinder because this residential scenario alone exceeds the Agency’s level of concern; thus,

33this scenario is also of concern when aggreg ated with dietary and drinking water routes of

exposure.

Table 9. Short Term Aggregate DWLOCs - Adults applying atraz i ne at 2 lb ai/A to law n s.

Exposure Scenario Aggregate MOE (Dermal and Inhalation) Short Term DWLOC (ppb)

(1) M i xi ng, l o adi ng, and appl y i ng l i qui d form ul at i ons vi a backpack sprayer 28,000 219

(2) M i xi ng, l o adi ng, and appl y i ng l i qui d form ul at i ons vi a l o w pressure handwand 1,600 273

(3) M i xi ng, l o adi ng, and appl y i ng l i qui d form ul at i ons vi a hose-end spray e r 640 105

(4) Loadi ng and appl y i ng granul ar form ul at i ons vi a pushtype spreader 11,000 159

(5) Loadi ng and appl y i ng granul ar form ul at i ons vi a bel l y gri nder 65 0

2) Adult Post-Application

Short-term estim ates of aggregate risk for adults from post-application exposures

com b ine dietary exposure and post-application derm al exposures after atrazine lawn treatm e nt .
Short-term derm al and dietary exposures have a com m on toxic effect: delayed puberty as a

biom arker for neuroendocrine effects.

Table 10 sum m a rizes the results of the Agency’s aggregate risk assessm ent for short-term exposures of adults exposed to atrazine-treated lawns im m e diately after application. Short-term aggregate risk estim ates do not exceed the Agency’s level of concern. W eekly concentrations of

atrazine and the chlorotriazine m e tabolites have been m easured in drinking water up to 89 ppb;

since this concentration is less than the rem a ining DW LOCs, the aggregate risk is acceptable.

Table 10. Short Term Aggregate DWLOCs - Adults exposed to atraz i ne after application to law n s at 2 lb ai/A.

Exposure Scenario (formulation) D ermal MOE Short Term DWLOC (ppb)

Derm al Turf C ont act (l i qui d) 510 130

Derm al Turf C ont act (granul ar) 1200 157

Derm al C ont act W a l k i ng/ Pl ay i ng Gol f (l i qui d) 7,800 210

Derm al C ont act W a l k i ng/ Pl ay i ng Gol f (granul ar) 16,000 215

Derm al C ont act Pushi ng Lawn M o wer (l i qui d) 16,000 214

34Table 10. Short Term Aggregate DWLOCs - Adults exposed to atraz i ne after application to law n s at 2 lb ai/A.

Exposure Scenario (formulation) D ermal MOE Short Term DWLOC (ppb)

Derm al C ont act Pushi ng Lawn M o wer (granul ar) 35,000 217

3) Child Post-Application

Short-term estim ates of aggregate risk to toddlers from post-application residential exposure to atrazine com b ine dietary exposures w ith post-application derm al and incidental oral exposures after atrazine lawn treatm e nt.

Aggregate risk estim ates for short-term expos ures to toddlers playing on liquid atrazinetreated lawns exceed EPA’s level of concern. Risks to children from aggregated oral residential post-application exposures (hand-to-m outh transfer of residues, grass and soil ingestion activities by toddlers on grass) are of concern for liqui d form ulations (MOE = 200); therefore, any aggregation through the derm al, inhalation or dietary pathways would result in risk estim ates that further exceed the Agency’s level of concern.

Toddlers’ risk estim ates from individual or aggregated (com bined) pathways for incidental oral exposures based on granular fo rm ulations do not exceed the Agency’s levels of concern; i.e., a MOE of 730. Toddlers’ risk es tim ates from derm al exposures based on granular

form ulations also do not exceed the Agency’s levels of concern; i.e., MOEs of 690 (for applications that are not watered-in im m e diately after application and 2000 for applications that

are watered-in im m e diately after application). Com b ined derm al and incidental oral exposures for toddlers result in a MOE of 350 or greater and also do not exceed the Agency' s level of

concern. Short-term DW LOCs for toddlers’ pos t application aggregate exposures, inclusive of

derm al, incidental oral, and dietary (food + drinking water) exposures, do not exceed HED’s

level of concern for granular form ulations watered-in after application to turf

. Short-term

DW LOCs for toddlers’ post application aggregate exposures exceed the Agency’s level of concern for granular form ulations.

Exposure to atrazine through ingestion of granules by toddlers result in MOEs of 16 to

110. Granule ingestion by toddlers is considered an episodic event (a stand alone incident) and has not been aggregated with either other inci dental oral exposures or derm al and dietary

exposures.

Table 11 below presents the short-term aggregate MOEs and DW LOCs for toddlers exposed to atrazine after lawn applications.

35Table 11. Short-Term Aggregate DWLOCs - Toddlers exposed to atraz i ne after liquid and granular applications to law n s.

Ty pe of Exposure Formulation/Application Rate (lb s ai/acre) Dermal MOE Aggregate

Inc i de ntal Or al

MOE S h o rt-Term DWLOC (ppb)

Derm al C ont act on Turf 2 l b ai / acre (l i qui d) 310 200 zero

Derm al C ont act on Turf 1 l b ai / acre (l i qui d) 610 390 zero

Derm al C ont act on Turf 2 lb ai/acre (granular)

wi t hout wat e ri ng-i n 690 730 12 - 14

Derm al C ont act on Turf 2 lb ai/acre (granular)

with waterin g

- in 2000 730 35 - 39

4. Occupational Risk

W o rkers handling pesticide products can be exposed to atrazine through m i xing, loading, and/or applying this pesticide, and through reentering treated sites. Occupational handlers of

atrazine include: individual farm ers and other gr owers who m i x, load, and/or apply pesticides;

com m e rcial, professional, or custom agricultural applicators; com m e rcial pest control operators;

and lawn care and turf m a nagem e nt professionals. The post-application occupational risk

assessm ent considered exposures to workers entering treated sites in agriculture. Risk for all of these potentially exposed populations is m easured by a Margin of Exposure (MOE) which

determ ines how close the occupational or residential exposure com e s to a No Observed Adverse Effect Level (NOAEL). Generally, MOEs greater than 100 do not exceed the Agency’s risk

concern.

a. Toxicity

The toxicity of atrazine is integral to assessing the occupational risk. The Agency has

conducted short-term and interm ediate-term derm al and inhalation exposure assessm ents for the occupational handler. In addition, the Agency has conducted short-term post-application derm al and inhalation exposure assessm ents. Long-term (chronic) occupational exposures are not anticipated based on atrazine’s use pattern.

All risk estim ates are based on the m o st current toxicity inform ation available for atrazine, including a 21-day derm al toxicity study. The toxicological endpoints, and other factors used in the occupational risk assessm ents for atrazine are sum m a rized in Table 12 below. Please note that the occupational derm al and inhalation endpoints are the sam e as those used in the dietary drinking water assessm ent and in the residential risk assessm ent.

A derm al absorption factor of 6% (rounded up from 5.6%) was selected, based on a

hum an study in which 10 volunteers were exposed to a single topical dose of atrazine. An inhalation absorption factor of 100% is applied. Th e FQPA Safety Factor is not applicable to the Occupational Risk Assessm ent.

36Table 12. Summary of Toxicological Endpoints and Other Factors Used in the

Atraz i ne Occupational Risk Assessment

Ex po sure Scenario Dose (mg/ kg/ d ay) UF 1 Endpoint S tudy

Dermal,

Short

- Term a NOAEL= 6.25

LOAEL = 12.5 100 Del a y e d preput i a l separat i on i n

m a l e offspri ng aft e r 30 day s of

dosi ng. Use of t h e derm al

penet r at i on fact or y i el ds a dose of

104 m g / kg/ day

. Pubert al assay (30­ day) NHEERL

p u b lish e d literatu re

Derm al,

In term ed iateTerm b NOAEL= 1.8

LOAEL = 3.65 100 At t e nuat i on of pre-ovul at ory l u t e ni zi ng horm one (LH) surge, as a

bi om arker i ndi cat i v e of hy pot hal a m i c funct i on di srupt i on Si x-m ont h LH surge- Rat

Inhal a t i on, Short

- Term c NOAEL= 6.25

LOAEL = 12.5 100 Del a y e d preput i a l separat i on i n

m a l e offspri ng aft e r 30 day s of

dosi ng. Pubert al assay (30­ day) NHEERL

p u b lish e d literatu re

Inhal a t i on,
In term ed iateTerm c NOAEL= 1.8

LOAEL = 3.65 100 At t e nuat i on of pre-ovul at ory l u t e ni zi ng horm one (LH) surge, as a

bi om arker i ndi cat i v e of hy pot hal a m i c funct i on di srupt i o n Si x-m ont h LH surge-Rat

1 UF = Uncertainty Factor (100 is the result of a 10x for interspecies variability and 10x for intraspecies extrapolation)

a = The NOAEL of 6.25 m g /kg/day is m u ltiplied by a 3.6 derm al penetration factor.

b = 6% dermal absorption factor for route-to-route extrapolation. c = 100% absorption factor for route-to-route extrapolation.

Atrazine has low acute derm al and inhalati on toxicity. It is non-irritating to skin,

m i nim a lly irritating to the eyes and is not a skin sensitizer. It is classified under Category III for acute oral toxicity. Table 13 sum m a rizes the acute toxicity of atrazine.

Table 13. Summary of Results from Acute Toxicity Studies of Technical Atraz i ne

Guideline

No. T e st Resul t s T oxi c Category

81-1 A cute Oral LD 50 - rat L D 50 > 1,869 m g / kg (M &F

com b ined) III

81-2 A cute Derm al LD 50 - rat L D 50 > 2,000 m g / kg (M &F

com b ined) III

37Guideline

No. T e st Resul t s T oxi c Category

81-3 A cut e Inhal a t i on LC 50 ­ rat LC 50 > 5.8 m g /L (M&F com b ined) IV

81-4 E y e Irri t a t i on - rabbi t N on-i rri t a nt IV

81-5 D erm a l Irri t a t i on - rabbi t N on-i rri t a nt IV

8 1

- 6 D erm a l Sen s itizatio n N o n

- sen s itizer

--­

b. Occupational Exposure

Several chem ical-specif i c studies that were subm itted to the Agency by the technical registrant were used together were used to assess the occupational handler risks from use of

atrazine for m o st exposure scenarios. Exposure studies subm itted to the Agency by the OutdoorResidential Exposure Task Force (ORETF) were also used in the occupational (and nonoccupational) risk assessm ents for applicators.

In addition, the Agency generated MOEs to assess risk to com m e rcial handlers engaged

in im pregnating atrazine onto dry bulk fertilizer using derm al and inhalation unit exposure data

from the Pesticide Handlers Exposure Database (PHED), Version 1.1 (August 1998). The

PHED scenario for m i xing/loading liquids using a closed system were used as a surrogate to

estim ate these exposures. However, such an exposure surrogate is less appropriate for

estim ating exposures due to transferring the treated dry bulk fertilizer from an auger truck to the application equipm ent. There are no data or reasonable surrogate available for this operation.

Three chem ical-specific studies, one of dislodgeable foliar residue on corn, and two of

transf erable turf residues (TTR), were subm itted to the Agency and used in the post-application occupational risk assessm ent. In addition, transfer coefficients used were based on data

subm itted by the Agricultural Reentry Task Force (ARTF), where possible. Most of the atrazine used in agriculture is applied to corn and sorghum early in the season, either before weeds

em erge or when the crops are quite sm all, generally less than 12 inches high. This, and the degree of m echanization in cultivating these crops, leads the Agency to conclude that postapplication exposure to workers is low.

Anticipated use patterns and application m e thods, range of application rates, and daily

am ounts treated were derived from current labe ling. Maxim u m application rates specified on atrazine labels were 2.0 lb ai/A, with a few exceptions. Maxim u m label rates were used to

estim ate handler exposure. The Agency uses acres treated per day values that are thought to represent an eight-hour workday for a particular type of application equipm ent or a specific crop.

Occupational handler exposure assessm ents are conducted by the Agency using different levels of personal protection. The Agency typically evaluates all exposures with baseline protection and then adds additional protective m easures using a tiered approach to obtain an appropriate MOE (i.e., going from m i nim a l to m a xi m u m levels of protection). The lowest suite

38of personal protective equipm ent (PPE) is baseline PPE. If required (i.e., MOEs are less than 100), increasing levels of risk m itigation PPE are applied. If MOEs are still less than 100, engineering controls (EC) are applied. The levels of protection that form ed the basis for calculations of exposure from atrazine activities include:

• B aseline: Long-sleeved shirt and long pants, shoes and socks (includes gloves for the applicator in scenario 5).

• PPE: B aseline + coveralls, chem ical-resistant gloves, and a dust/m ist respirator (see table for specifics by scenario)

• E ngineering controls: E ngineering controls, such as closed cab tractor for application scenarios, or a closed m i xing and loading system such as a farm

closed m echanical transfer system for liquids or a package based

system

. Som e engineering controls are not feasible for certain

scenarios. Som e form ulation types qualify as engineering controls for the purpose of controlling exposure during m i xing and loading, such as water soluble packets.

c. Occupational Handler Risk Summary

Inhalation and derm al exposure to atrazine can result from occupational use. The Agency assessed derm al and inhalation risks (MOEs) for each crop currently registered for

atrazine. For atrazine, occupational MOEs great er than 100 are not of risk concern to the Agency.

1) Agricultural Handler Risk

The Agency has determ ined that there is potential atrazine exposure to m i xers, loaders, applicators, and other handlers using atrazine in accordance with the current use patterns.

Fourteen m a jor agricultural handler exposure scenarios were identified for atrazine, as listed

below. The m a jor handler scenarios involved m u ltiple crops and application rates, resulting in several different exposure estim ates. The largest agricultural use of atrazine involves the

m i xing, loading and application of atrazine to row crops and results in the largest potentially exposed occupational population.

(1a) m i xing/loading liquid form ulations for aerial application, (1b) m i xing/loading liquid form ulations for groundboom application, (1c) m i xing/loading liquid form ulations for rights-of-way sprayer application to roadside, (1e) m i xing/loading/incorporating liquid form ulations into liquid and dry bulk

f

e rtilizer (com m e rcial & on-f a rm techniques), (2a) m i xing/loading dry flowable form ulations for aerial application, (2b) m i xing/loading dry flowable form ulations for groundboom application, (2c) m i xing/loading dry flowable form ulations for rights-of-way sprayer application to roadside, (3) l oading granular form ulations,

39(4) a pplying liquids with aircraft, (5) a pplying liquids with groundboom sprayer, (6) a pplying liquids to roadsides with rights-of-way sprayer, (8) a pplying im pregnated dry bulk f e rtilizer with a tractor-drawn spreader, (9) a pplying granular form ulations with a tractor-drawn spreader, (15) flagging for aerial spray applications (16a) m ixing/loading wettable powder form ulations for aerial application; and (16b) m i xing/loading wettable powder form ulations for groundboom application.

PPE requirem e nts on current atrazine labels are typically long-sleeved shirt, long pants, shoes, socks and waterproof gloves. Mixers and loaders m u st also wear protective eyewear. (m ixers/loaders).

As sum m a rized in Table 14, occupational risks are of concern (i.e MOEs < 100) for som e scenarios even when m a xim u m PPE are utilized. Handler risks are also of concern f o r a f e w scenarios with engineering controls. Engineering controls are considered to be the m a xim u m feasible m itigation. These involve several scenarios for the incorporation of atrazine into liquid or dry bulk fertilizer, handlers m i xing and loadi ng wettable powders for application to 350 acres of sugarcane at 4 lb ai/A, and handlers applying li quids with a right of way sprayer to 40 acres of

roadsides at 2 lb ai/A.

40Table 14.Occupational Handler Aggregate (Dermalplus Inhalation) Margins of Exposure (PHED)ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsShort TermIntermediateTermShort TermIntermediateTermShort TermIntermediateTermMixer/Loader(1a) Liquidformulations foraerial applicationConifer forestsChristmas tree farms435020.424861520130Sugarcane435020.4248615201302.630.738194800200Chemical fallow312001na96na200na35020.6330826901701.412001na206na430na35051.37081701500370CRP or grasslands212001na144na300na35040.94951201000260CornSorghum212001na144na300na35040.94951201000260112002na289na610na350729912402100520Sod Farms4(FL)35020.424861520130235041495120100026041ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm(1b) Liquidformulations forgroundboomapplicationMacadamia nutsGuavaConifers4808210842702300560Sugarcane48082108427023005602.68012316674103500870Chemical Fallow34502na257na540na2004157814012003001.44504na550na1200na2009212383102600640CRP or grasslands24503na385na810na200628672101800450CornSorghum24503na385na810na20062867210180045014506na771na1600na20012317344303600900Roadsides14062158669210018,000450023184335110091002300Sod farms4(FL)80821084270230056028016421675404600110042ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm(1c) Liquidformulations forRoadsides14062158669210018,0004500rights-of-waysprayerBermuda grass rights-of-way2403184335110091002300(1e) Incorporatingliquidformulations intoliquid or drybulkfertilizerCommercial fertilizer for corn,sorghum (PHED data)2960 tonssee engineering controls64na500 tons120361960 tons120na500 tons23072Commercial fertilizer for corn,2500 tonssee engineering controls17067sorghum (Helix studydata)1see engineering controls350130On-farmfertilizer for corn,21608na700na1900nasorghum116015na1400na3800na(2a) Dryflowablefor aerialapplicationConifer forestsChristmas tree farms4350661610526380130Sugarcane43506616105263801302.63501002516140580140Chemical fallow3120026na41na150na3508822140355001201.4120055na87na320na35019047300741100270CRP or grasslands2120038na61na220na43ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm3501303321052750190Corn2120038na61na220naSorghum35013033210527501901120077na122na440na350260654201001500370Sod farms4(FL)35066161052638013023501303321052750190(2b) Dryflowablefor groundboomapplicationMacadamia nutsGuavaConifers480290714591101600410Sugarcane4802907145911016004102.6804401107061702500630Chemical fallow345068na109na400na20015038245618802201.4450150na233na840na200330825251301900470CRP or grasslands2450100na163na580na20023057367911300330CornSorghum2450100na163na580na2002305736791130033044ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm1450210na326na1200na2004601107341802600650Roadsides1402300570367291013,00033002401200290183645066001600Sod farms4(FL)802907145911016004102805801409182303300820(2c)Dryflowablefor rights-of-wayRoadsides1402300570367291013,00033002401200290183645066001600(3) GranularformulationsSod farms28012003105023120062,00015,000(16a) Wettablepowders for aerialapplicationSugarcane43501.25.2174.1580932.61.83266.3380140Chemical Fallow312000.5na6.5na150na1.41na14na310naCorn, Sorghum212000.7na9.7na220na3502.44338.2750190112001.4na19na440na3504.776616150037045ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm(16b) Wettablepowders forgroundboomapplicationMacadamia nuts4401016150363300820Sugarcane42002.13297.2660160Sod farms (FL)4805.2873181600410Applicator(4) Applyingliquids withaircraftConifer forestsChristmas tree farms4350See engineering controls850210Sugarcane4350See engineering controls8502102.6351300320Chemical fallow31200See engineering controls330na35011002801.41200710na3502400600CRP or grasslands21200See engineering controls500na3501700420CornSorghum21200See engineering controls500na350170042011200990na3503400840Sod farms4(FL)350See engineering controls8502102350170042046ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm(5) Applyingliquids bygroundboom4Macadamia nutsGuavaConifers48086021016904204000980Sugarcane480860210169042040009802.6801300330260064061001500Chemical fallow3450200na40199940na20046011090122021005201.4450440na8582102000na200990240193148045001100CRP or grasslands2450310na6011501400na20069017013523303200790CornSorghum2450310na6011501400na200690170135233032007901450610na12023002800na2001400340270467064001600Roadsides24035008506759170016,00039001406900170013519330032,0007900Sod farms4(FL)8086021016904204000980280170043033808408000200047ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTerm(6) Applyingliquids with a rightofway sprayerRoadsides240671630074not feasible14013033601150not feasible(8) Applyingimpregnatedfertilizer with atractor-drawnspreaderCornSorghum2320190na660na1000na160380na1300na1900na1320380na1300na1900na160900na2600na4000na(9) Applyinggranular productwith a tractordrawn spreaderOn-farmfertilizer for corn,sorghum220061015022215503200790801500380555314007900200012001200300444211006400160080300075011,100270016,0004000Flagger(15) FlaggingspraysConifer forestChristmas tree farms435031076466120910220Sugarcane4350310764661209102202.63504801207171801400350Chemical fallow335041010062115012003001.435088022013313302600640CRP or grasslands23506201509312301800450CornSorghum23506201509312301800450135012003101863460360090048ScenarioCrop/Use SiteRate1AcresLevels of ProtectionBaselinePPE2ECsInter-Inter-InterShort TermmediateShort TermmediateShort TermmediateTermTermTermSod farms4(FL)35031076466120910220235062015093123018004501lbai/A orlbai/gal2PPE Includes long-sleeved shirtand long pants, coveralls, chemicalresistantgloves, and a respirator.(16a) and (16b) are listed using minimumppe (single layer, gloves, dust/mistrespirator).3pounds of fertilizer treated per day4Scenario#5, Applying Liquids byGroundboom:the baseline assessmentincludes gloves.492) Law n Care Operator Handler Risk

The Agency has determ ined that there is potential for atrazine exposure to Lawn Care Operators (LCOs) and other handlers m i xing, lo ading and/or applying atrazine to turf in accordance with the current use pattern. Fifteen m a jor exposure scenarios have been identified

and are listed below.

(1b) m i xing/loading liquid form ulations for groundboom application, (1d) m i xing/loading liquid form ulations for lawn handgun application (LCO), (2b) m i xing/loading dry flowable for groundboom application, (3) l oading granular form ulations, (5) applying liquids with groundboom sprayer, (7) a pplying with a lawn handgun or com p ressed air sprayer, (9) a pplying granular form ulations with a tractor-drawn spreader, (10) m i xing/loading/applying with a backpack sprayer, (11) m i xing/loading/applying liquid form ul ations with a low pressure handwand, (12a) m ixing/loading/applying liquids with a lawn handgun or com p ressed air sprayer, (12b) m i xing/loading/applying W DG form ulations with a lawn handgun, (12c) m ixing/loading/applying water soluble powder form ulations with a lawn handgun, (13) loading/applying granular form ula tions with a push type spreader, and (14) loading/applying granular form ulations with a bellygrinder.

The risk assessm ents for these scenarios are sum m a rized in Table 15 below. W ith the use of PPE, all scenarios are acceptable.

Table 15. Law n Care Operator Margins of Exposure

Scenario Crop/

Use

Site Rate (lb

a i/A) Acres L e vel s of Protecti o n

Ba seline PPE ECs

Short

term Inter

me d i a t e

term Short

term Inter

me d i a t e

term Short

term Inter

me d i a t e

term

Mixer/Loader

(1b) Li qui d

form ulations for groundboom

ap p licatio n gol f

course

tu rf 2 4 0 3 1 8 4335 1100 9100 2300

(1d) Li qui d

form ulations for

l a wn handgun

ap p licatio n lawn

, gol f

courses 2 100 12 3 1734 430 3600 900

(2b) Dry fl owabl e for groundboom

ap p licatio n gol f

course

tu rf 2 4 0 1200 290 1836 450 6600 1600

50Scenario Crop/

Use

Site Rate (lb

a i/A) Acres L e vel s of Protecti o n

Ba seline PPE ECs

Short

term Inter

me d i a t e

term Short

term Inter

me d i a t e

term Short

term Inter

me d i a t e

term

(3) Granular

form ul at i ons (l oadi ng) gol f

course

tu rf 2 4 0 2500 610 10,047 2500 120K 31,000

Mixer/Loader/Applicator

(10) Li qui d vi a backpack sprayer lawn s, gol f

courses 2 5 see PPE 428 110 not feasi b l e

(11) Li qui d vi a l o wpressure handwand lawn s, gol f

courses 2 5 7 2 1549 380 not feasi b l e

(12a) Li qui d vi a l a wn handgun and

com p ressed air spray e r 1 lawn s, gol f

courses 2 5 see PPE 1400 gl oves 340 gl oves n o t feasib le

(12b) W DG vi a l a wn handgun 1 lawn s, gol f

courses 2 5 see PPE 1100 gl oves 290 gl oves n o t feasib le

(12c) W SP vi a l a wn handgun 1 lawn s, gol f

courses 2 5 see PPE 920 gl oves 230 gl oves n o t feasib le

(13) Granul ar vi a push type spreader (ORETF) 1 lawn s, gol f

courses 2 5 1500 380 2100 gl oves 520 gl oves n o t feasib le

(14) Granul ar vi a bel l y gri nder lawn s, gol f

courses 2 1 330 82 616 150 not feasi b l e

Appl i cat or

(5) Appl y i ng l i qui ds by groundboom gol f

course

tu rf 2 4 0 3500 850 6759 1700 16,000 3900

(7) Appl y i ng l i qui ds

wi t h a handgun (ORETF) 1 lawn s, gol f

courses 2 5 see PPE 980 gl oves 240 gl oves n o t feasib le

(9) Appl y i ng granul ar form ul at i ons wi t h a tractor-drawn spreader gol f

course

tu rf 2 4 0 3000 750 11,100 2700 16,000 4000

Foot not e: PPE for scenari o s 12(a), 12(b), 12(c), 13 and 7, i n cl ude basel i n e (l ong-sl eeved shi r t

, pant s, shoes and

51 1socks) pl us gl oves.

3) Post-Application Occupational Risk

Post-application exposure to workers through entry into agricultural fields treated with atrazine was also considered in the occupational risk assessm ent. These activities result in potential short-term exposures. All post-application risk estim ates were below the Agency’s

level of concern. MOEs ranged from 100 to 220,000.

4) Epidemiology Data

An epidem iology study was conducted of workers at the Syngenta St. Gabriel plant

where atrazine is m a nufactured. That study repor ted a statistically significant increase in the incidence of prostate cancer am ong plant workers. The Agency, upon review of this study, requested additional inform ation on the exposure profile of the em ployees diagnosed with prostate cancer and this inform ation was provided and reviewed. Based on this review, it appears that m o st of the increase in prostate cancer incidence at the St. Gabriel plant is likely due to intensive prostate specif i c antigen (PSA) screening of em ployees conducted as part of the

com p any’s “W ellness Program .” The study was insufficiently large and has lim itations that prevent ruling out atrazine as a potential contributor to the increase observed. On balance, however, a role for atrazine seem s unlikely because prostate cancer was found prim arily in

active em ployees who received intensive PSA screening; there was no increase in advanced

tum o rs or m o rtality; and proxim ity to atrazine m a nuf acturing did not appear to be correlated with

risk.

Atrazine has also been tied to inflam m a tion of the prostate in laboratory anim als and changes in testosterone levels at high doses. However, neither condition has been tied to the increased risk of prostate cancer and the Agency concludes the anim al data do not provide biologically plausible evidence to support atrazine as a cause of prostate cancer.

Other cancers besides prostate were found to have an elevated, though not statistically significant, increase in risk at the St. Gabriel plant. Other studies have suggested an increased risk for ovarian, breast, and other cancers, including non-Hodgkin’s lym phom a. However, these studies are at best prelim inary and should not serv e as a basis for im plicating atrazine as a hum an carcinogen due to their m e thodological lim itations.

In addition, the Agency understands that Syngenta will be conducting a case control study on m a le em ployees at the St. Gabriel plant to exam ine the relationship between atrazine exposure estim ates and the presence or absence of prostate cancer am ong cases and controls.

W e expect to receive and review this study dur ing the third quarter of 2003 and to incorporate

the results into the October revision to the IRED.

Further, the National Cancer Institute’s (NCI) prelim inary analysis of the National

Institute of Environm ental Health Sciences (NIEHS) Agricultural Health Study has found no association between prostate cancer and atrazine in one of the largest and best-designed

52epidem iological studies ever conducted. NCI expects to publish a final analysis this sum m e r. The Agency will f u lly consider additional results f r om the NCI analysis when it becom e s available.

B. Environmental Risk Assessment

A sum m a ry of the Agency’s environm ental risk assessm ent is presented below. For detailed discussions of all aspects of the environm ental risk assessm ent, see the April 22, 2002, Reregistration Eligibility Science Chapter f o r Atrazine - Environm ental Fate and Ef f

ects Chapter

and the “Steeger Docum e nt” available in the public docket and on the internet at www.epa.gov/pesticides/reregistration. There were no m a jor revisions to the ecological risk

assessm ent.

1. Environmental Fate and Transport

Atrazine is m obile and persistent in the environm ent and, as such, atrazine is expected to be present in surface water and groundwater. This is confirm e d by widespread detection in surface water and groundwater. The m a in route of dissipation is m i crobial degradation under

aerobic conditions.

Atrazine can reach nearby non-target plants, soil, and surface water via spray drift during application. Atrazine is applied directly to target plants during foliar application or directly to soil during the m o re frequent pre-plant and pr e-em ergent applications. Atrazine can be transported indirectly to soil due to incom p lete interception during foliar application and washoff subsequent to foliar application. Atrazine is unlikely to undergo rapid degradation on foliage because atrazine is resistant to abiotic hydrolysis (stable at pHs 5, 7, and 9), resistant to direct aqueous photolysis (stable under sunlight at pH 7), and is only m oderately susceptible to degradation in soil (aerobic laboratory half-lives of 3-4 m onths). For aquatic environm ents reported half-lives were m u ch longer. In an anaerobic aquatic study, atrazine’s overall half-life, water half-life, and sedim e nt half-life were given as 608, 578, and 330 days, respectively.

Atrazine is also unlikely to undergo rapid volatilization from foliage because it has a relatively low Henry’s Law constant (2.6 X 10 -9 atm @ m 3 /m ol). But this m a y be offset by

atrazine’s relatively low octanol/water coefficient (Log K

ow = 2 .7), and soil/water partitioning coefficents (Freundlich K ads values < 3 and often < 1). In addition, atrazine has relatively low adsorption characteristics; this indicates that atrazine m a y undergo substantial washoff from foliage.

In terrestrial field dissipation studies perfor m e d in Georgia, California, and Minnesota, atrazine dissipated with half lives of 13, 58, and 261 days, respectively. The differences between these reported half-lives could be attributed to the tem p erature variation between the studies in

which atrazine was seen to be m o re persistent in colder clim ate. Long term field dissipation studies also indicated that atrazine could persist over a year in such clim atic conditions. A forestry field dissipation study in Oregon (aerial application of 4 lb ai/A) estim ated an 87 day half-life for atrazine on exposed soil, a 13 day ha lf-life in foliage, and a 66 day half-life on leaf

53litter.

Atrazine m e tabolites, desethylatrazine (DEA) and desisopropylatrazine (DIA) were detected in all anaerobic aquatic m e tabolism studies subm itted, and hydroxyatrazine and

diam inochloroatrazine (DACT) were detected in all but one of the anaerobic aquatic m e tabolism

studies subm itted. Desethylhydoxyatrazine (D EHA) and desisopropylhydroxyatrazine (DIHA)

were also detected in one of the aerobic studies. All of the chlorinated m e tabolites and hydroxy

com pounds detected in laboratory m e tabolism studies were present at m u ch less than 10% of applied atrazine; thus, are not considered by the Agency to be “m ajor degradates.”

For studies lim ited to several m onths, the relative concentrations of the m e tabolites in soil were generally as follows: DEA>DIA>DACT~hydroxyatrazine. However, for an aerobic

soil m e tabolism study and an anaerobic aquatic m e tabolism study both lasting a year, the concentration of hydroxyatrazine was com p arable to that of DEA over the last few m onths of the

studies. In addition, som e literature indicates that higher quantities of hydroxyatrazine can be

form ed in soil and in sedim e nt under acidic conditions. Other hydroxy com pounds have only rarely been detected in lab studies.

The soil/water partitioning of atrazine, DE A, DIA, and DACT are relatively low as shown by Freundlich adsorption coefficients of < 3 and often < 1 for 4 different soils. The Freundlich adsorption constants for hydroxyatrazine are substantially greater, being approxim a tely 2 for sand, but 6.5, 12.1, and 390 for a sandy loam , loam , and clay soil, respectively. No adsorption/desorption data are available for other hydroxy-triazine degradates. However, the higher soil/water partitioning exhibited by hydroxyatrazine com p ared to atrazine suggests that the other hydoxy-triazines are likely to exhibit higher soil/water partitioning than corresponding chloro-triazine degradates.

In a lim ited study on atrazine and its chlorodegradates in surface water source CW S, the detection of all was relatively widespread. However, atrazine predom inated with the relative order of concentrations generally bei ng as follows: atrazine>>DEA>DIA~DACT.

In a 1999 study of rural wells, the four hydroxy com pounds were detected. Hydroxyatrazine was detected the m o st frequently and generally at the highest level, but not to

the sam e extent as atrazine or the chlorinated m e tabolites. Unlike in surface water, where atrazine concentrations were generally m u ch greater than chlorotriazine concentrations, the DEA

and DACT concentrations in rural wells were often com p arable to those of atrazine. The relative order of concentrations found in rural wells was generally atrazine~DEA~DACT>DIA>hydroxyatrazine .

The relatively widespread detection of atrazine and various chlorinated m e tabolites in the surface water study on m e tabolites and in the 1999 rural well study is consistent with the widespread use of atrazine, the persistence of atrazine and the m obility of atrazine and its

chlorinated m e tabolites. The lower f r equency of detection and generally lower levels of the hydroxyatrazine in the rural well study is consistent with its higher soil/water partitioning than

atrazine and the chlorinated m e tabolites.

54The available fate and ground water data indicate that hydroxy com pounds are unlikely to significantly contam inate surface water. They are not appreciably form ed in soil, and they are likely to exhibit higher soil/water partitioning than corresponding chlorinated m e tabolites. In addition, they were detected m u ch less frequently and at m u ch lower levels than the chlorinated

m e tabolites in rural wells. However, hydroxyatrazine was detected at concentrations up to 6.5 ppb in 6% of rural wells sam p led. Also, there have been reported concentrations of hydroxyatrazine in soil som e tim es approaching and possibly in som e cases (e.g., acidic soils) exceeding that of DEA.

Atrazine should be som e what persistent in groundwater and in surface water with relatively long hydrologic residence tim es where advective transport is lim ited. The reasons for this are the resistence of atrazine to abiotic hydrolysis and to direct aqueous photolysis, its only

m oderately susceptibility to biodegradation, and its lim ited volatilization potential as indicated by a relatively low Henry’s Law constant. Atrazi ne has been observed to rem a in at elevated concentrations longer in som e reservoirs than in flowing surface water or in other reservoirs with

presum ably m u ch shorter hydrologic residence tim es in which advective transport greatly lim its its persistence.

The relatively low soil/water partitioning of atrazine and chlorinated m e tabolites indicates that their concentrations in or on suspended and bottom sedim e nt will be in equilibrium

with the residues in the water colum n. However, despite relatively low soil/water partitioning,

lim ited data indicated that activated carbon can be effective in reducing atrazine and its triazine

m e tabolite concentrations by several fold, depending upon the frequency and conditions of its

use.

Volatility as a route of field dissipation raises concerns about the atm o spheric fate ofatrazine, its aerial transport and whether aerial deposition poses the potential for risks to nontarget terrestrial plants. The potential for adverse effects on sensitive, non-target crops and plants from atm o spheric deposition is uncertain. Atrazine has been widely detected in rainfall, with the highest concentrations occurring in the Midwestern corn belt during the application season (m id-April through m i d- July). In addition, DEA and DIA were also detected in rainfall together with atrazine. High ratios of DEA to atrazine were attributed to atm o spheric degradation. Mass deposition of atrazine and its m e tabolites is higher in the m i dwestern corn belt, and decreases with distance away from the corn belt.

2. Risk to Terrestrial Organisms

The Agency’s ecological risk assessm ent com p ares toxicity endpoints from ecological

studies to estim ated environm ental concentrations (EECs) based on environm ental fate characteristics and pesticide use data. To evaluate the potential risk to non-target organism s from the use of atrazine products, the Agency calculates a Risk Quotient (RQ) by determ ining the ratio of the EEC to the toxicity endpoint values, such as the m e dian lethal dose (LD50) or the

m e dian lethal concentration (LC50). These RQ values are then com p ared to the Agency’s levels of concern (LOCs) to determ ine whether or not a chem ical, when used as directed, has the potential to cause adverse effects to non-target organism s. In general, the higher the RQ, the

55greater the concern. W h en the RQ exceeds the LOC for a particular category (e.g., endangered species), the Agency presum es a risk of concern to that category of non-target organism s. The LOCs and the corresponding risk presum ptions are presented in Table 16.

Table 16. LOCs and Associated Risk Presumptions

If... Then the Agency presumes....

Birds and Mammals

Acut e R Q > LOC of 0.5 acut e ri sk

Acute RQ > LOC of 0.2 r isk that m a y be m itigated through restricted use classification

Endangered Speci es Acut e R Q > LOC of 0.1 acute effects m a y occur in endangered species

C h roni c R Q > LOC of 1 c hroni c ri sk and chroni c effect s m a y occur i n non-t a rget organi sm s

Aquatic Animals

Acut e R Q > LOC of 0.5 acut e ri sk

Acute RQ > LOC of 0.1 r isk that m a y be m itigated through restricted use classification

Endangered Speci es Acut e R Q > LOC of 0.05 acute effects m a y occur in endangered species

C h roni c R Q > LOC of 1 c hroni c ri sk and chroni c effect s m a y occur i n non-t a rget organi sm s

Terrestrial and Semi-Aquatic Plants

Acute RQ > LOC of 1 acute risk

Acute RQ > LOC of 1 r isk that m a y be m itig ated through restricted use classification

Endangered Speci es Acu t e RQ > LOC o f 1 acute effects m a y occur in endangered species

C h roni c R Q > LOC of 1 c hroni c ri sk and chroni c effect s m a y occur i n non-t a rget organi sm s

a. Toxicity (Haz ard) Assessment

Atrazine is practically non-toxic to slightly toxic to birds and m a m m a ls, and relatively non-toxic to honey bees.

As expected for a herbicide, atrazine is toxic to non-target plants. Terrestrial plant seedling germ ination tests indicate that cucum b er is the m o st sensitive dicot and oats is the m o st
sensitive m onocot. Terrestrial plant seedling em ergence tests indicate that the dicot m o st sensitive to atrazine is carrot, and the m onocots m o st sensitive to atrazine are oats and ryegrass. Terrestrial plant vegetative vigor tests indicate that the m o st sensitive dicot is cucum b er and the

56m o st sensitive m onocot is onion.

The acute and chronic toxicity values used to assess risks are presented in Tables 17 and

18 below.

Table 17. Summary of Toxicity Data for Terrestrial Animals

Species Acute Toxicity (ppm) C hr oni c T oxi ci ty (ppm)

LD 50 Acute

Oral

T oxi ci ty 5-day

LD 50 Subacute Dietary

T oxi ci ty NOAEC/

LOAEC Affected Endpoints

Atraz i ne

Nort hern bobwhi t e quai l

C o l i nus vi rgi n i anus 940 sl i ght l y

t oxi c >5,000 pract i cal l y

non-t oxi c 225/ 675 decreased egg product i on, i n crease in d e fectiv e eg g s
, decreased em bryo

v i ab ility, d ecreased body wei ght

Honey bee Ap is meliferu s 96.69 rel a t i v el y

non-t oxi c -- -- -- --

Laborat ory rat (m g/ kg) 1,869

- 3,080 practicall

y nont oxi c -- -- 50 See health effects endpoi nt s

Table 18. Summary of Toxicity Data for Non-Target Terrestrial Plants

Species Seedling Germination

T oxi ci ty Seedling Emergence

T oxi ci ty Vegetati ve Vi gor T oxi ci ty

E C 25/

EC0 5 Endpoint E C 25/

NOAEC Endpoint E C 25/

NOAEC Endpoint

M onocot s

Oat - Avena sat i v a 1.8/ 0.12 reduct i on i n radi cal l e ngt h 0.0004/

0.0025 reduct i o n in d r y wt. 2.4/ 2.0 r educt i o n in d r y wt.

Oni on - Alliu m cep a <4.0/ < 4.0 no effect 0.009/

0.005 reduct i o n in d r y wt. 0.61/ 0.5 r educt i o n in d r y wt.

Dicots

Carrot - Daucus carot a <4.0/ < 4.0 no effect 0.003/

0.0025 reduct i o n in d r y wt. 1.7/ 2.0 r educt i o n in p l an t
hei ght

Cucum b er - Cucumis sativus 0.80/ 0.60 reduct i on i n radi cal l e ngt h 0.013/

0.005 reduct i o n in d r y wt. 0.008/

0.005 reduction in dry weight

57b. Exposure and Risk - Birds and Mammals

The Agency’s acute ecological risk assessm ent for terrestrial wildlife considers exposure

to atrazine from the ingestion of residues on f ood. Terrestrial EECs were derived for the three

m a jor crops using the m a xim u m labeled use rates (4 lb ai/A for sugarcane and 2 lb ai/A for corn and sorghum ) and the highest value m easured for foliar dissipation half-life from the application

of atrazine to turf in the Southeastern United States: 17 days. Since foliar dissipation half-lives

are used in estim ating these EECs, the EECs better represent post-em ergent applications than pre-plant and pre-em ergence applications m a de directly to soil.

No acute LOCs are exceeded for m a m m a ls; however, in som e scenarios, restricted use and endangered species LOCs are exceeded. RQ values for sm all m a m m a ls are cited in the table

below. Acute endangered species LOCs are exceeded for sm all herbivorous m a m m a ls (RQ range: 0.0092 - 0.13) at 1.1 and 1.2 lb ai/A. All acute avian RQs are significantly below all LOCs indicating that there is negligible potential f o r acute risks to birds

The chronic LOC is exceeded for birds (RQ range: 0.08 - 4.3) and m a m m a ls (RQ range:

1.6 - 96) suggesting the potential for chronic risks to m a m m a ls and birds from atrazine applied at typical and m a xim u m use rates.

It is im portant to consider that exposure of birds and m a m m a ls to atrazine applied as a pre-plant or pre-em ergent herbicide is prim arily a result of ingestion of earthworm s and other soil organism s that can serve as a food source and inadvertent ingestion of soil. Methods are not

available to determ ine the levels of atrazine that could occur in soil and in earthworm s and other soil organism s that are used as food sources by birds and m a m m a ls. The resulting levels of atrazine in soil and soil organism s that can serve as a source of food for birds and m a m m a ls are expected to be considerably lower than estim ated levels in plants used as food sources. As such, risk quotients based on EECs from m a xim u m foliar dissipation half-life data, as presented in this

docum ent, are over-estim ates for birds and m a m m a ls that are exposed from ingestion of soil organism s.

The prim ary effects of concern for herbicides and wildlife are indirect.

Table 19. Acute and Chronic Risk Quotients for Terrestrial Organisms

Organi s m Siz e of Organi s m

(grams) Ra ng e o f EEC (ppm) Acute RQ Subacute

Di etary RQ Chronic RQ (Repro)

Sugarcane: 1 Preplant Aerial Applicatio n 4 lb a i/A (ma x i mum la beled use ra te)

M a m m a l i a n Herbi vores 15 60 - 960 0.031 - 0.49

-- 1.2 - 19.2

M a m m a l i a n Insect i vores 15 60 - 540 0.031 - 0.27

M a m m a l i a n Grani vores 15 60 0.0067

58Table 19. Acute and Chronic Risk Quotients for Terrestrial Organisms

Organi s m Siz e of Organi s m

(grams) Ra ng e o f EEC (ppm) Acute RQ Subacute

Di etary RQ Chronic RQ (Repro)

Avi a n Speci es 60 - 960

-- <0.012 - <0.19 0 .27 - 4.3

Sugarcane: 1 Preplant Aerial Applicat io n 2

. 6 lb a i/A (ty pica l use ra te)

M a m m a l i a n Herbi vores 15 39 - 624 0.020 - 0.32

– 0 .78 - 12.48

M a m m a l i a n Insect i vores 15 39 - 151 0.020 - 0.08

M a m m a l i a n Grani vores 15 39 0.0044

Avi a n Speci es 39 - 624

-- <0.0078 ­

<0.12 0.17 - 2.8

Corn and Sorghum: 1 Preplant Aerial Applicat io n a t 2

. 0 lb a i/A (ma x i mum la beled ra te)

M a m m a l i a n Herbi vores 15 30 - 480 0.015 - 0.24

-- 0.6 - 9.6

M a m m a l i a n Insect i vores 15 30 - 270 0.015 - 0.14

M a m m a l i a n Grani vores 15 30 0.34

Avi a n Speci es 30 - 480

-- <0.0060 ­

<0.096 0.13 - 2.1

Co rn: 1 Prepla nt Aeria l Applica t io n a t 1

. 1 lb a i/A (ty pica l use ra te)

M a m m a l i a n Herbi vores 15 16.5 - 264 0.0084 - 0.13

-- 0.3 - 5.28

M a m m a l i a n Insect i vores 15 16.5 - 148.5 0.0084 - 0.075

M a m m a l i a n Grani vores 15 16.5 0 .0019

Avi a n Speci es 16.5 - 264

-- <0.0033 ­

<0.053 0.73 - 1.2

59Table 19. Acute and Chronic Risk Quotients for Terrestrial Organisms

Organi s m Siz e of Organi s m

(grams) Ra ng e o f EEC (ppm) Acute RQ Subacute

Di etary RQ Chronic RQ (Repro)

Sorghum: 1 Preplant Aerial Applicatio n at 1.2 l b ai / A (typi cal use rate)

M a m m a l i a n Herbi vores 15 18 -288 0.0092 - 0.15

-- 0.36 - 5.76

M a m m a l i a n Insect i vores 15 18 - 162 0.0092 - 0.082

M a m m a l i a n Grani vores 15 18 0.0020

Avi a n Speci es 18 - 288

-- <0.0036 ­

<0.058 0.08 - 1.1

c. Exposure and Risk - Terrestrial Plants

Atrazine applications to crop and non-crop areas result in exposure to non-target plants in areas adjacent to treated fields via spray drift and/or runoff. The Agency’s assessm ent com p ares standard residue values for runoff and drift for exposure and com p ares these exposure values to toxicity data available for non-target species. Spray drift levels for ground and aerial applications are 1 and 5 percent, respectively. Atrazine is highly m obile in soils and has a low soil-water partitioning coefficient and a water solubility value of about 33 ppm

. Its runoff is

estim ated at 2 percent. The scenario for plants growing in dry areas receive runoff from 1 hectare to 1 hectare, while a 1-hectare wet area receive s runoff from 10 hectares. All plant toxicity values are present as pounds active ingredient per acre (lbs ai/A). The EC25 values are used to calculate risk quotients for the typical non-target plants and the NOAEC values are used for endangered and threatened plant species. Although the Agency currently only has data on crop species, the results are assum e d to represent a range of wild plants. The assessm ent assum e s that terrestrial plants living in wetter habitats are at greater risk because they are exposed to runoff

m o re than drier areas. The assessm ent resulted in exceedences for ground and aerial applications of atrazine at typical and m a xim u m labeled rates. RQs based on the m a xim u m labeled use rate are presented in Table 20 below.

RQs from three test species exceed the typical plant LOC from spray drift alone (cucum ber, soybeans, and cabbage), 8 test species (in dry areas) or 9 test species (in wetter areas) exceeded the LOC from spray drift plus runoff. Both m onocot and dicot species have

exceeded the level of concern.

Endangered species exceedences for direct effects on terrestrial plants indicate potential risks to endangered species. RQs from 9 test species exceeded the endangered species LOC

from spray drift alone or from spray drift plus runoff. The level of concern for endangered terrestrial plant species is exceeded for both m onocots and dicots. These results indicate concern for endangered plant species growing in areas adj acent to atrazine-treated fields from com b ined spray drift and runoff.

60A ground application of 2 lbs ai/A poses a dim i nished risk to adjacent crops com p ared to 4 lb ai/A applications, but only one of these species (i.e., soybeans from spray drift) would no longer exceed the acute level of concern. At the typical corn use rate of 1.1 lbs ai/A, the nontarget crops at risk are cucum b ers from spray dr ift, 7 out of 9 non-target species growing in dry habitats, and all 9 non-target species, if grown in sem i -aquatic habitats. Risk quotients for endangered plant species indicate concern for e ndangered species growing in areas adjacent to

atrazine-treated fields from com b ined spray drift and runoff.

Table 20. Risk Quotients for Terrestrial Plants

Crop 4 lbs ai./A; Aerial Application 4 lbs ai./A; Ground Application

Spray Drift (5% ) Spray Drift + Runoff Spray Drift (1% ) Spray Drift + Runoff

Dry Areas W et Areas Dry Areas W et Areas Ty p E S 1 Ty p E S T y p ES Ty p E S Ty p E S T y p ES

Carrot 0.12 0.10 83 99 230 270 0.024 0.02 40 48 280 340

Oats 0.083 0.10 62 99 170 270 0.017 0.02 30 48 210 340

Ryeg rass <0.05 < 0.05 62 50 170 140 <0.01 < 0.01 30 24 210 170

Lettu ce 0.61 0.80 50 50 140 140 0.12 0.16 24 24 170 170

Onion 0.33 0.40 28 50 76 140 0.066 0.08 13 24 93 170

Cucum b er 25 40 19 50 52 140 5.0 8 .0 9.2 2 4 6 5 170

Soybean 7.7 1 0 1 .3 9.9 3.5 27 1.5 2 .0 0.63 4.8 4 .4 34

C a bbage 14 40 18 25 49 68 2.9 8.0 8.6 1 2 6 0 8 4

Tom a to 0.28 0.40 7.3 25 20 68 0.056 0.08 3.5 12 25 84

Co rn <0.05 < 0.05 <0.06 < 0.06 <0.17 < 0.17 <0.01 < 0.01 <0.03 < 0.03 <0.21 < 0.21

1 ES - Endangered Speci es; Ty p. - Ty pi cal Speci es

3. Risk to Aquatic Species

To assess the risks to aquatic plants and anim als from the use of atrazine, the Agency first conducted a screening-level RQ assessm ent sim ilar to that described above for terrestrial organism s. This screening-level assessm ent was conducted only for freshwater species. The Agency also conducted a refined assessm ent to further evaluate the potential risks to aquatic organism s and local com m unities and populations. Estuarine and saltwater species were assessed as part of the refined assessm ent.

a. Toxicity (Haz ard) Assessment

Atrazine is slightly to m oderately toxic to freshwater fish and slightly to highly toxic to

61freshwater invertebrates. Atrazine is slightly to m oderately toxic to estuarine/m a rine fish and slightly to very highly toxic to estuarine/m a rine invertebrates. Tables 21 and 22 sum m a rizes the endpoints used in the screening-level risk assessm ent of aquatic anim als and plants.

Table 21. Summary of Toxicity Data for Aquatic Organisms

Species Acute Toxicity (ppb) Ch ronic Toxicity (ppb)

96-hr

LC 50 Acute Toxicity NOAEC/

LOAEC Affected Endpoints

Freshwater Fish

R a i nbow t r out - Oncorhynchus mykiss 5,300 m oderat e l y t oxi c

- - - -

B r ook t r out - Sal vel i nus t ont i nal i s 6,300 m oderat e l y t oxi c 65/ 120 reduced m ean l e ngt h, m ean body

wei ght

Freshwater Invertebrates

M i dge - C h i r onomus t e nt ans 720 hi ghl y t oxi c 110/ 230 reduct i on i n pupat i on and adul t

em ergence

Scud - Gammarus fasciatus 5700 m oderat e l y t oxi c 60/ 140 reduct i on i n devel opm ent

Mysid shrim p - Ameri c amysi s bahi a 1000 hi ghl y t oxi c 80/ 190 reduct i on i n adul t
survival 5400 m oderat e l y t oxi c

Table 22. Summary of Toxicity Data for Non-Target Aquatic Plants

Species Short Term Exposure (10 days or l e ss) Longer Term Exposure (>10 days)

Concen

tration (ppb) Response Concen

tration (ppb) Response

Freshwater Vascular Plants

Duckweed - Lemna gi bba 170 50% reduct i on i n growt h 37 50% reduct i o i n growt h (LOAEC = 3.4, 19%

reduct i on i n growt h ; NOAEC < 3.4)

43 50% reduct i on i n growt h (NOAEC = 10)

Freshwater Non-Vascular Plants

Chlorophyceae - Kirchneria subcapi t a t

a ( S el enast r um capri c ornut um) 49 50% reduct i on i n cel l growth (NOAEC = 16) -- --

62b. Exposure and Risk

For the screening-level assessm ent, to assess potential risk to aquatic anim als and plants in ponds, the Agency uses a com puter m odel to predict the EECs of atrazine in water. Peak

EECs are com p ared to acute toxicity endpoints to derive acute RQs. Norm ally, chronic RQs are derived using 96-hour and 21- to 90-day EECs, co rresponding to the duration of the test. For atrazine, 21-day EECs were generally used for chronic exposures, because the difference in EEC

values is sm all. To estim ate chronic risk to fish, both 21-day and 90-day EECs were used. EECs are presented in Table 23 below. Calculated RQs of concern are sum m a rized below and presented in Table 23.

Table 23. EECs Used in the Atraz i ne Aquatic Risk Assessment for Ponds

Crop Use Rates (lb ai/A) Atr a z i ne EEC Value s ppb ( F g/L)

Peak Conc. 96-hour Average 21-day Average 60-day Average 90-day Average

Sugarcane 4 .0 205 204 202 198 194

2.6 133 133 131 129 126

Corn 2.0 38.2 38.0 37.2 35.5 34.2

1.1 21.0 20.9 20.5 17.7 18.8

Sorghum 2.0 72.7 72.3 70.6 67.7 65.9

1.2 43.6 43.4 42.4 40.6 39.5

For the sugarcane scenarios, atrazine applied at either the 2.6 lbs/ai/A or 4.0 lbs ai/A rate exceeds the levels of concern for acute toxicity to aquatic plants, restricted use for aquatic invertebrates, and endangered species for aquatic invertebrates and aquatic vascular plants. In addition, the chronic LOC is exceeded for aquatic plants, fish and aquatic invertebrates resulting

from both the m a xim u m use rate and the typical use rate for sugarcane.

For the 2.0 lb rate corn scenario, atrazine exceeds the levels of concern for acute toxicity for aquatic plants and for endangered species for aquatic invertebrates and aquatic vascular plants. The acute RQs for freshwater fish, and the chronic RQs for freshwater fish and aquatic

invertebrates do not exceed levels of concern. For the 1.1 lb. rate corn scenario, atrazine exceeds the LOC for endangered species for aquatic vascular plants. The rem a ining calculated RQs do not exceed levels of concern.

For the 2.0 lb rate sorghum scenario, atrazine exceeds the LOC for acute toxicity for aquatic plants, restricted use for aquatic invertebrates, endangered species for aquatic invertebrates, and aquatic vascular plant species. The levels of concern for chronic effects are exceeded by chronic RQs for aquatic plants, fish and aquatic invertebrates. For the 1.2 lb. Rate sorghum scenario, atrazine exceeds the LOC for acu te toxicity for vascular plants, endangered species for aquatic invertebrates, and endangered species for aquatic vascular plants. The acute and chronic RQs for freshwater fish and aquatic invertebrates do not exceed levels of concern.

63Table 24. Acute and Chronic Risk Qu otients for Freshw ater Aquatic Species

Organi s m Acute C hronic

EEC ( ppb) RQ EEC (ppb) RQ

Sugarcane: 1 Prepl a nt Aeri al Appl i c ati o n at 4.0 l b ai / A

Freshwat er Fi sh 205 0.039 194 - 202 2.9 - 3.1

Aquat i c Invert ebrat e 0.28 202 3.4

Freshwater Vascular Plant 5 .5

-- --

Freshwater Vascular Plant (NOEC)* >60.3

- - - -

Freshwater Algae 4 .2

-- --

Sugarcane: 1 Prepl a nt Aeri al Appl i a ti on at 2.6 l b ai / A

Freshwat er Fi sh 133 0.025 126 - 133 1.9 - 2.0

Aquat i c Invert ebrat e 0.18 131 2.2

Freshwater Vascular Plant 3 .6

-- --

Freshwater Vascular Plant (NOEC)* >39.1

- - - -

Freshwater Algae 2 .7

-- --

Corn: 1 Prepl a nt Aeri al Appl i c ati o n at 2.0 l b ai / A

Freshwat er Fi sh 38.2 0 .0072 34.2 - 37.2 0 .53 - 0.58

Aquat i c Invert ebrat e 38.2 0 .053 37.2 0 .63

Freshwater Vascular Plant 37.2 1 .0

Freshwater Vascular Plant (NOEC)* 37.2 > 11

-- --

Freshwat er Al gae 38.2 0 .78

- - - -

Corn: 1 Prepl a nt Aeri al Appl i c ati o n at 1.1 l b ai / A

Freshwat er Fi sh 21.0 0 .0040 18.8 - 20.5 0 .29 - 0.32

Aquat i c Invert ebrat e 21.0 0 .029 20.5 0 .34

Freshwater Vascular Plant 20.5 0 .56

- - - -

Freshwater Vascular Plant (NOEC)* 20.5 > 6.0

- - - -

64Table 24. Acute and Chronic Risk Qu otients for Freshw ater Aquatic Species

Organi s m Acute C hronic

EEC ( ppb) RQ EEC (ppb) RQ

Freshwat er Al gae 21.0 0 .43

- -

--

Sorghum: 1 Prepl a nt Aeri al Appl i c ati o n at 2.0 l b ai / A

Freshwat er Fi sh 72.7 0 .014 65.9 - 70.6 1 .0 - 1.1

Aquat i c Invert ebrat e 72.7 0 .10 70.6 1 .2

Freshwater Vascular Plant 72.7 2 .0

-- --

Freshwater Vascular Plant (NOEC)* 72.7 > 21

-- --

Freshwat er Al gae 72.7 1 .5

-- --

Sorghum: 1 Prepl a nt Aeri al Appl i c ati o n at 1.2 l b ai / A

Freshwat er Fi sh 43.6 0 .0082 39.5 - 42.4 0 .61 - 0.65

Aquat i c Invert ebrat e 43.6 0 .061 42.4 0 .71

Freshwater Vascular Plant 43.6 1 .2

-- --

Freshwater Vascular Plant (NOEC)* 43.6 > 13

-- --

Freshwat er Al gae 43.6 0 .89

- - - -

* Endangered speci es R Q cal cul a t i on

In addition to the risks described above, indir ect effects on fish and aquatic invertebrates

m a y be severe due to the loss of up to 60 to 95 percent of the vegetative cover, which provides habitat to conceal young fish and aquatic inverteb rates from predators. Num e rous studies have described atrazine’s ability to inhibit photosynthesis, change com m unity structure, and cause the

m o rtality of aquatic flora at concentrations between 20 and 500 ppm

.

5. Refined Aquatic Assessment

The refined atrazine aquatic risk assessm ent focuses on aquatic plants and invertebrates and the potential f o r ef f

ects on sensitive plant species to result in com m unity-level im pacts that affect a range of aquatic organism s. The assessm ent is broken down by the type of water body (i.e., sm all static fresh water bodies such as ponds, flowing fresh water such as stream s and rivers, larger bodies of fresh water such as lakes and reservoirs, and estuarine and m a rine habitats). Exposure for these three types of aquatic environm ents was estim ated using PRZMEXAMS m odeling sim u lations (ponds) and m onitoring data (stream s, lakes and reservoirs, and

estuarine/m a rine environm ents - refined aquatic assessm ent). The April 22, 2002,

Environm ental Fate and Effects Chapter presents fi gures that plot atrazine concentrations against

65exceedence probabilities to illustrate the effects that are likely or estim ated to occur in these aquatic environm ents.

The Agency’s refined aquatic risk assessm ent is based on ecotoxicological data,

m i crocosm and m e socosm studies, and the m onitoring data described above. A large num ber of laboratory, m i crocosm
, m e socosm , and actual field studies found in the literature suggest that

atrazine concentrations m easured in the environm ent could reach levels that are likely to have negative im pact on sensitive aquatic species and com m unities.

Tables 25, 26 and 27 sum m a rize the toxicological endpoints used in the refined risk

assessm ent.

Table 25. Key Endpoints for the Lentic Freshw ater Environment (e.g., reservoirs, lakes)

. The Endpoints Chosen for Use in the Refined Risk Assessment are Bolded.

K e y G r oup of

Non-target

O r ganism s Type of Study Measurem ent Endpoint T est Organism s /

Effect Assessm ent Endpoint

Fish L a b A cute Fish ( 96- hour s) L C 50 =
5, 300 F g/L Rainbow tr out / Mortality Fish Mortality Estim ated to Occur at 5, 300 F g/L

L a b C hr onic Fish ( 44- weeks)

NOAEC = 65 F g / L; LOAEC=

120 F g/L ; M A T C = 88 F g/L Br ook tr out / [7. 2

% red. m ean length, 16 % r e d.

m ean body

weight] Reduction in Fish Growth Estim ated to

Occur at 88 F g/L

Distr i bution of

Lab Data 10 th centile value = 62 F g/L F r e shwater Aquatic Anim al

Chr onic Data Fish Population Reductions Estim a ted

to Occur at 62 F g/L

Field ( m esocosm s ) 96% Reduction in # of Young

Fish Occurred at 20 F g/L ( C aused by L o ss of Food and Habitat) Bluegill sunfish Fish Populations Lik e ly to be

Reduced at 20 F g/L due to Loss of

Food and Habitat

Invertebrates L a b A cute I nver t ebr a te ( 48- hour )

LC 50 = 720 F g/L Midge / Mortality Invertebrate Mortality Estim ated to

Occur at 720 F g/L

L a b C hr onic I nver t ebr a te ( 48- hour )

NOAEC = 60 F g / L; LOAEC=

140 F g/L ; M A T C = 92 F g/L Scud / [25 % r e d. in developm ent of

F 1 to seventh instar] Reduction in I nver t ebr a te Populations

Estim ated to Occur at 92 F g/L

Distr i bution of

Lab Data 10 th centile value = 62 F g/L F r e shwater Aquatic Anim al

Chr onic Data Reduction in Invertebrate Populations

Estim a ted to Occur a t 6 2 F g/L

Field 59- 65% Reduction in Daphnid population gr owth occur r e d at

10 F g/L over 18- day s Daphnids Invertebrate Populat ions Lik e ly to be

Reduced at 10 F g/L

Non-Vascular

Pla n ts Lab A cute Algae (1-week) EC 50 = 1

F g/L Four species [41- 93%

r e duction in

chlor ophy ll

pr oduction] Reduction in Pr im ar y Pr oduction

Estim ated to Occur at 1 F g/L

66K e y G r oup of Non-target

O r ganism s Type of Study Measurem ent Endpoint T est Organism s /

Effect Assessm ent Endpoint

Distr i bution of

Lab Data 10 th centile value = 32 F g/L for acute effects on phy toplankton,

and 2. 3 F g/L f o r chronic ef f ects on plants Freshwater Aquatic Plant

Data Acut e Ef f ect s on P h yt oplank t o n
Est i m a t e d at 32 F g/L and Reductions

in Prim a r y Pro ductio n Estim a ted to

O ccur at 2. 3 F g/L

M i cr ocosm 23% Reduction in gr oss pr im ar y

pr oduction 10 F g/L ( a t day 2) ;

r ecover y by day 7 phy toplankton Reduction in Pr im ar y Pr oduction

Estim ated to Occur at 10 F g/L

Field 42% Reduction in phy toplankton biom ass ( a t day s 2- 7) occur r e d at 20 F g/L phy toplankton Reduct i on in P r im ary P r oduct i on Lik e ly to Occur at 20 F g/L

Vascular P l ant s L a b A cute ( 14- day s ) E C 50 = 37 F g/L D uckweed [50%

r e duction in

gr owth] Reduction in M acr ophy tes E s tim ated to

Occur at 37 F g/L

Distr i bution of

Data 10 th centile value = 18 F g/L for

acute effects on m acr ophy tes,
and 2. 3 F g/L f o r chronic ef f ects on plants Freshwater Aquatic Plant

Data Acute Effects on Macrophytes

Est i m a t e d at 18 F g/L and Reductions in Macrophyte Populations Estim a ted

t o O ccur at 2. 3 F g/L

M e socosm 60% Reduction of m acr ophy te vegetation occur r e d at 20 F g/L ; by M a y of following y ear
, 95%

Reduction of m acr ophy tes M acr ophy tes Reduction in Macrophytes (num ber & diversity) Lik e ly to Occur at 20 F g/L

Table 26. Key Endpoints for the Lotic Freshw ater Environment (e.g., streams). The Endpoints Chosen for Use in the Refined Risk Assessment are Bolded.

Key Group of

Non -target Organisms Ty pe of Study M e a sur e m e n t Endpoint T e s t Organisms /

Effect Asse ssme n t Endpoint

Fish L a b A cute Fish ( 96- hour s) L C 50 =
5, 300 F g/L Rainbow tr out / Mortality Fish Mortality Estim ated to Occur at 5, 300 F g/L

L a b C hr onic Fish ( 44- weeks)

NOAEC = 65 F g / L; LOAEC=

120 F g/L ; M A T C = 88 F g/L Br ook tr out / [7. 2

% red. m ean length, 16 % r e d.

m ean body

weight] Reduction in Fish Growth Estim ated to

Occur at 88 F g/L

Distr i bution of

Lab Data 10 th centile value = 62 F g/L F r e shwater Aquatic Anim al

Chr onic Data Fish Population Reductions Estim a ted

to Occur at 62 F g/L

Invertebrates L a b A cute I nver t ebr a te ( 48- hour )

LC 50 = 720 F g/L Midge / Mortality Invertebrate Mortality Estim ated to

Occur at 720 F g/L

L a b C hr onic I nver t ebr a te ( 48- hour )

NOAEC = 60 F g / L; LOAEC=

140 F g/L ; M A T C = 92 F g/L Scud / [25 % r e d. in developm ent of

F 1 to seventh instar] Reduction in I nver t ebr a te Populations

Estim ated to Occur at 92 F g/L

Distr i bution of

Lab Data 10 th centile value = 62 F g/L F r e shwater Aquatic Anim al

Chr onic Data Invertebrate Population Reductions

Estim a ted to Occur a t 6 2 F g/L

67Key Group of

Non -target Organisms Ty pe of Study M e a sur e m e n t Endpoint T e s t Organisms /

Effect Asse ssme n t Endpoint

Outdoor Str eam Significant I n cr ease in day tim e and nighttim e invertebrate drift

occur r e d at 22 F g/L due to increased predation var i ous species of

stream dwelling

in v e rteb rates Invertebrate Populat ions Lik e ly to be

Reduced at 22 F g/L

Non-Vascular

Pla n ts Lab A cute Algae (1-week) EC 50 = 1

F g/L Four species [41- 93%

r e duction in

chlor ophy ll

pr oduction] Reduction in Pr im ar y Pr oduction

Estim ated to Occur at 1 F g/L

Distr i bution of

Lab Data 10 th centile value = 32 F g/L for acute effects on phy toplankton,

and 2. 3 F g/L f o r chronic ef f ects on plants Freshwater Aquatic Plant

Data Acut e Ef f ect s on P h yt oplank t o n
Est i m a t e d at 32 F g/L and reductions in prim ary production estim a ted to

occur at 2. 3 F g/L

Stream (f

irst order adjacent to

corn f i eld in Canada) 79% ( m ean) Reduction in T o tal Phy t oplankton Counts at 2. 62

F g/L ( m ean; r a nge = 0. 211 ­

13. 9) phy toplankton Reduct i on in P r im ary P r oduct i on Lik e ly t o O ccur at 2. 62 ( 0

. 211 - 13. 9)

F g/L

Outdoor

Artificial

Stream s Depr ession of Photosy n thesis at

10 F g/L Various species of

stream algae. Photosy n thesis

r e duction

m easur ed by open

water oxy gen

m e thods. Reduct i on in P r im ary P r oduct i on Lik e ly to Occur at 10 F g/L

Vascular P l ant s L a b A cute ( 14- day s ) E C 50 = 37 F g/L D uckweed [50%

r e duction in

gr owth] Reduction in M acr ophy tes E s tim ated to

Occur at 37 F g/L

Distr i bution of

Lab Data 10 th centile value = 18 F g/L for

acute effects on m acr ophy tes,
and 2. 3 F g/L f o r chronic ef f ects on plants Freshwater Aquatic Plant

Data Acute Effects on Macrophytes

Est i m a t e d at 18 F g/L and Reductions

in M a cro phy tes Estim a ted to Occur

at

2. 3 F g/L

Table 27. Key Endpoints for the Estuarine/Marine Environment (e.g., estuaries, tidal , marshes). Endpoints Chosen for Use in the Refined Risk Assessment are Bolded.

Key Group of

Non -target Organisms Ty pe of Study M e a sur e m e n t Endpoint T e s t Organisms /

Effect Asse ssme n t Endpoint

Fish L a b A cute Fish ( 96- hour s) L C 50 =
2, 000 F g/L Sheepshead

m i nnow / Mortality Fish Mortality Estim ated to Occur at 2, 000 F g/L

Lab C hronic Fish NOAEC = 1,900

F g/L ; L OAE C= 3400 F g/L ;
M A T C = 2542 F g/L Sheepshead

m i nnow [89 %

r e d. Juv. sur v ival] Reduction in Fish Populations E s tim ated

to Occur at 2542 F g/L

Distr i bution of

Lab Data 10 th centile value = 23 F g/L S altwater Aquatic

Anim al Chr onic

Data Fish Population Reductions Estim a ted

to Occur at 23 F g/L

Invertebrates Lab A cu te In v e rteb rate LC 50 = 94

F g/L Copepod ( Acartia

tonsa ) Invertebrate Mortality Estim ated to

Occur at 94 F g/L

68ute E ffects on Phy t oplankton E s tim ated at 32 F g/L and Reductions in Pr im ar y Pr oduction E s tim ated to Occur at 2. 3 F g/L Key Group of

Non -target Organisms Ty pe of Study M e a sur e m e n t Endpoint T e s t Organisms /

Effect Asse ssme n t Endpoint

Distr i bution of

Lab Data 10 th centile value = 23 F g/L S altwater Aquatic

Anim al Chr onic

Data Invertebrate Population Reductions

Estim a ted to Occur a t 2 3 F g/L

Lab C hronic Invertebrate NOAEC =

80 F g/L ; L OAE C= 190 F g/L ;
M A T C = 123 F g/L M y sid [37 % r e d. Adult survival] Reduction in I nver t ebr a te Populations

Estim ated to Occur at 123 F g/L

Non-Vascular

Pla n ts L a b A cute ( 120- hour s) Algae L C 50 = 22 F g/L Algae (Chry s ophy ceae;
I s ochrysis galbana ) Algae Mortality Es tim ated to Occur at

22 F g/L

Distr i bution of

Lab Data 10 th centile value = 27 F g/L for acute effects on phy toplankton,

and 9. 1 F g/L f o r chronic ef f ects on plants Saltwater Aquatic

Plant Data Acut e Ef f ect s on P h yt oplank t o n Est i m a t e d at 27 F g/L and Reductions

in Prim a r y Pro ductio n Estim a ted to

O ccur at 9. 1 F g/L

Vascular P l ant s L a b S ignificant r e duction in dr y weight occur r e d at 10 F g/L

(calculated MATC f r om NOAEC=7.5 and

L OAE C=14. 3) Sago Pondweed Reduction in M acr ophy tes E s tim ated to

Occur at 10 F g/L

Distr i bution of

Lab Data 10 th centile value = 9.1 F g/L for

chronic ef f ects on plants Saltwater Aquatic

Plant Data Reductions in Macrophytes

Estim a ted to Occur a t 9

. 1 F g/L

M i cr ocosm 16% Reduction in T uber

for m ation; 55% Reduction in

Biom ass over r e pr oductive

season at 4 F g/L Wild Celery ( Vallisneria

A m ericana ) Reduction in Macrophytes Lik e ly to

Occur at 4 F g/L

a. Ponds

Based on m odeling sim u lations, it is possible that for m onths every year, atrazine concentrations in ponds from use on sorghum and sugarcane exceed the levels at which studies have shown reductions in fish and invertebrate populations, m acrophytes, and prim ary production (>20ppb). For corn, m odeling sim u lations indicate that atrazine concentrations in ponds exceed the levels at which studies have shown reductions in fish populations, invertebrate populations, m acrophytes, and prim ary production in 70 to 83% of the years. From 70 to 75% of the years, atrazine concentrations in ponds from use on sugarcane exceed the levels at which reproduction studies have shown reductions in i nvertebrate populations and fish growth. For sorghum , the percentage of exceedences are from 2.8 and <5% of the years.

b. Lakes and Reservoirs

Monitoring data in lakes and reservoirs have indicated that a num ber of drinking water sites have atrazine concentrations greater than 20 ppb in the finished water. This is the level at which reductions in fish populations, invertebrate populations, m acrophytes, and prim ary production has been observed in sim u lated field studies.

69c. Streams

The highest atrazine concentrations occur in brief pulses following rain events and are usually associated with the next rain event after an application. Atrazine concentrations in

stream s vary frequently, depending on usage and rainfall patterns, and vary from watershed to watershed, depending on the size of the watershed, the intensity of agricultural activity, and the

flow volum e and location of the watershed.

Reductions in invertebrate populations and prim ary production were likely to occur in 12

to 34% of the 129 Midwestern stream s sam p led following atrazine applications in 1989. In addition, based on sim u lated field testing and laboratory testing m acrophytes m a y be reduced in

52 to 63% of the stream s sam p led in the weeks following atrazine applications. Reduction in prim ary production is also possible at these levels. Later in the season, concentrations that would affect prim ary production and m acrophytes were seen in only 1% of the 143 stream s

sam p led. Based on sam p ling in 1995, reduction in invertebrate populations are prim ary production are likely to occur in 17 to 35% of the 50 Midwestern stream s sam p led following atrazine applications. In addition, based on laboratory testing, m acrophytes m a y be reduced in

64% of the stream s sam p led following atrazine applications.

The highest pulse concentrations seen in stream s exceed m a ny of the assessm ent endpoints for non-target organism s. W h ile the dura tion of these high concentrations is not likely to be long since pulses of runoff tend to m ove quickly downstream , they m a y last for hours, especially during the Spring and during runoff even ts when m a ny fields in a watershed are being

treated with atrazine around the sam e tim e. Thus, it is possible that reductions in invertebrate populations and prim ary production could occur as a result of post-application stream

contam ination from the Spring application of atrazine. The frequency of such reductions occurring m a y be low considering the frequency of the pulses above 10 ppb and depending upon

the flow volum e of each stream

. The frequency of sim ilar reductions occurring in rivers is probably lower than for stream s since the peaks and average concentrations of atrazine are lower

in rivers.

Based on NAW QA m onitoring data for 40 agricultural sites, 11 to 35% of the 40 sites

exceed atrazine concentrations at which inve rtebrate populations and prim ary production occur,

based on the m a xim u m atrazine concentrations seen. NAW QA m onitoring data, however, were not designed to tim e m onitoring to correspond with atrazine treatm ent and m a y underestim ate concentrations likely to be present in stream s.

d. Estuaries

Based on m a xim u m atrazine concentrations in Louisiana, 77% of the sites sam p led

exceed concentrations at which reductions in m acrophytes occur. This falls to 26 to 61% for the

m ean concentration. About 30% of the sites based on m a xim u m concentrations and about 7%

based on m ean concentrations exceed the concentrations at which reductions in fish and invertebrate populations occur.

70Maxim u m atrazine concentrations in the Chesapeake Bay exceed levels that are likely to

reduce m acrophytes for 8% of the site and year com b inations sam p led. Atrazine could be contributing to reductions in subm erged aquatic vegetation at certain sites in the Bay. It is possible that atrazine and other herbicides are a source of stress to aquatic vegetation. This,

com b ined with eroding sedim e nt could negatively affect estuarine ecosystem s.

6. Risk to Endangered Species

Endangered species LOCs are exceeded for terrestrial plants, birds and sm all m a m m a ls

from the agricultural uses of atrazine. However, risks to endangered birds and m a m m a ls are not anticipated from the dietary residues based on the m e thods and tim ing of atrazine applications. The risk exceedences for endangered terrestrial plants are based on spray drift and runoff into the

habitats for terrestrial and sem i -aquatic plants.

Endangered aquatic species LOCs are exceeded for som e agricultural uses of atrazine. Acute risks to endangered freshwater invertebrate s and aquatic vascular plants are exceeded for all crop uses except for the typical use rate on corn (1.1 lb ai/A.) Chronic levels of concern for endangered species are exceeded for fish and aquatic invertebrate reproduction for all use rates, except for corn and the typical use rate on sorghum

.

Atrazine was included in the form al Section 7 consultations with FW S for the rangeland/pastureland and the forest cluster re views in 1984. The Biological Opinions for both reviews stated that these uses of atrazine would jeopardize the continued existence of over 60 species of plants associated with rangeland and te n species of plants associated with forests. Atrazine was also included in the sorghum cl uster review in 1983, and the Biological Opinion found possible jeopardy to several species of fish pl us one insect (loss of habitat) and one plant species.

In addition, atrazine was one of 109 active ingredients included in the reinitiated Biological Opinion of 1989 from the FW S. This Opinion was prim arily for aquatic species. In this Opinion, FW S found jeopardy to nine species of freshwater fish, two freshwater crustaceans,

four am phibians and twelve species of plants fo r its uses on field crops, rangeland and forests.

FW S provided “Reasonable and Prudent Alternatives” (RPAs) for each jeopardized species and “Reasonable and Prudent Measures” (RPMs) for 43 non-jeopardized species to m i nim i ze incidental take of these latter species. These consultations and the findings expressed in the Opinions, however, are based on old labels and application m e thods, less refined risk assessm ent procedures and an older approach to consultation which is currently being revised through interagency collaboration.

W h en the regulatory changes recom m e nded in this IRED are im plem ented and the ecological effects and environm ental fate data are subm itted and accepted by the Agency, the

Reasonable and Prudent Alternatives and Reas onable and Prudent Measures in the Biological Opinion(s) m a y need to be reassessed and m odified based on the new inform ation.

The Agency is currently engaged in a Proactive Conservation Review with FW S and the

71National Marine Fisheries Service under section 7(a)(1) of the Endangered Species Act. The objective of this review is to clarify and develop consistent processes for endangered species risk

assessm ents and consultations. Subsequent to the com p letion of this process, the Agency will reassess the potential effects of atrazine use to federally listed threatened and endangered species. At that tim e the Agency will also consider any regulatory changes recom m e nded in the IRED that are being im plem ented. Until such tim e as this analysis is com p leted, the overall

environm ental effects m itigation strategy articulated in this docum ent and any County Specific

Pam phlets described in Section IV which address atrazine, will serve as interim protection

m easures to reduce the likelihood that endangered and threatened species m a y be exposed to

atrazine at levels of concern.

The potential adverse effects of atrazine on hom ing and reproduction in endangered

salm on and other anadrom ous fish species is currently uncertain. The laboratory study of olfactory function in m a ture Atlantic salm on parr and the effect of atrazine in the range of 0.5

F g/L for sensing fem a le horm ones in urine and behavior to ground salm on skin is notable. This is so especially if the effects are significant on salm on reproduction at such a low atrazine concentration, because existing concentrations in stream s inhabited by endangered salm onids

m a y exceed this level for prolonged periods. Atrazine concentrations are likely to be their highest in the late spring and early sum m e r following applications, at a tim e when salm on are returning from the ocean to spawn. It is unclear from the results of the test by Moore and

W a ring (1998) whether the effect on olfactory function is m a nifested in m a ture adult salm on and

what effect it m i ght have on reproduction and recruitm ent. These data are prelim inary and additional studies are necessary to determ ine if there are adverse atrazine effects on adult salm on hom ing and adult m a le m ilt production responses to fem a le horm ones in ovulating fem a le urine. Further study is also needed on whether those effects could be significant to reproduction and

recruitm ent.

7. Ecological Incident Reports

The Agency received 109 ecological incident reports on atrazine between 1991 and 2001. Of the 109 incidents, thirteen are classified as “Unlikely,” 50 are listed as “Possible,” and two

are “Unrelated.” In only one case, a 1996 cotton use in Louisiana, were casualties (fish) analyzed f o r atrazine residues. Shad and carp tested positive f o r atrazine, but the conclusion was that atrazine was unlikely to be the cause of m o rtality. Forty of the 109 incidents are considered “Probable,” and four incidents are listed as “Hi ghly Probable.” The 4 incidents listed as “Highly

Probable” include 3 hom e lawn use incidents and 1 corn use incident. The corn use incident reported affecting 100 bass and 100 bream resulting from a registered use. The three hom e lawn incidents were lawn applications that affected th e turf itself; two were concluded to be accidental

m i suse, and the third was a registered use that affected grass and non-target plants.

The forty “Probable” incidents include: 16 cases affecting corn; 11 affecting grass; 11

f i sh kills; 1 bird kill; and af f

ects on ornam e ntals, f r uit trees, berries, garden, oats, vegetation around an atrazine/cyanazine-treated field (runoff), and greenhouse plants (pond irrigation water). Four “probable” incidents are classified as accidental m i suse: two cases from corn use, pears, raspberry and oats and grass and ornam e nt als; and two lawn m i suse cases affecting grass

72and bluegrass.

Atrazine alone is not very toxic to the birds, m a m m a ls, and aquatic anim als cited in m o st
of these incidents. In none of these cases has evidence been provided that firm ly dem onstrate that atrazine has produced the reported effects. In m a ny cases, the inference of these reported incidents to atrazine effects is likely due to the wide spread use of atrazine and the proxim ity of the atrazine application and tim ing to the occurrence to the incident. About 60 percent of the reported fish kills listed under atrazine in the incident record occur during the Spring when atrazine is applied, soils are saturated and heavy rainfall is frequent. Heavy runoff m a y carry atrazine, other pesticides and organic loads into surface waters. The high volum e and widespread use of atrazine increases the probability of co-occurrence of f

i sh kills with atrazine applications.

8. Endocrine Disruption

Atrazine has been associated with sub-lethal effects in aquatic organism s and am phibians in research presented in the open, peer-reviewed literature. These include potential ef f

ects on
endocrine-m ediated processes in frogs at ~ 0.1 F g/L and in largem outh bass at ~ 50 F g/L, as well as olfactory effects in salm on at ~ 0.5 F g/L. In addition, som e studies have been conducted

to address this issue and found that these effects were not dem onstrated.

The Agency’s ecological risk assessm ent does not suggest that endocrine disruption, or potential effects on endocrine-m ediated pathways, be regarded as an regulatory endpoint at this

tim e. Nor does the Agency have evidence to state that there is no reliable evidence that atrazine

causes endocrine effects in the environm ent. Based on the existing uncertainties in the available database, atrazine should be subject to m o re definitive testing once the appropriate testing protocols have been established. The Agency is aware that several pertinent studies are being perform e d at this tim e by researchers that m a y to reduce som e of the uncertainties in understanding potential atrazine effects on am phibian endocrinology and reproductive and developm ental responses. The Agency has com m itted to provide these studies along with other available studies, a sum m a ry of the available data and m e thodologies and various data analyses for an external scientific review by the Fede ral Insecticide, Fungicide and Rodenticide Act (FIFRA) Science Advisory Panel (SAP) at a public m eeting which is scheduled for June, 2003. The Agency anticipates that the results from this SAP m eeting will provide significant input to enable it publish an am endm ent to this IRED in October 2003 which will address the issue of the potential effects of atrazine on am phibian endocrinology and developm ent.

7374IV. Interim Risk Management and Reregistration Decision

A. Determination of Interim Reregistration Eligibility

Section 4(g)(2)(A) of FIFRA calls for the Agency to determ ine whether products containing a specific active ingredient are eligib le for reregistration after subm ission of the

relevant data. The Agency has previously identified and required the subm ission of the generic data ( i.e. , data specific to an active ingredient) to support reregistration of products containing

atrazine.

The Agency has com p leted its assessm ent of the ecological and occupational risks associated with the use of currently registered pesticides containing the active ingredient atrazine, as well as an atrazine-specific dietary risk assessm ent and residential risk assessm ent
that have not considered the cum u lative effects of the triazines, as a class. The ecological

assessm ent does not address the potential for effects on am phibian endocrinology and reproductive and developm ental responses. As m e ntioned above, the Agency will publish an

am endm ent to this IRED in October 2003 which will address the issue. Based on a review of the generic data, other special studies, and public com m e nts on the Agency’s assessm ents, EPA has

sufficient inform ation on the hum an health and ecological effects of atrazine to m a ke interim decisions as part of the tolerance reassessm ent process under FFDCA and reregistration under
FIFRA, as am ended by FQPA. The Agency has determ ined that atrazine products, based on currently approved labeling, pose unreasonable dietary, residential, occupational, and ecological

risks. However, the Agency believes that these risks can be m itigated through routine changes to pesticide labeling and through actions designed to further prevent risks from occurring that are

described in a Mem o randum of Agreem ent with the registrants. Accordingly, the Agency has

determ ined that the active ingredient atrazine is eligible f o r reregistration provided that: (i) the additional data needs that the Agency has identif ied are addressed; (ii) the risk m itigation

m easures outlined in this docum ent are adopted, and label am endm ents are m a de to reflect these

m easures; (iii) the consideration of cum u lative risk for the triazines supports a final reregistration eligibility decision; and (iv) the Mem o randum of Agreem ent is im plem ented. Further m itigation

m easures and additional data requirem e nts m a y be warranted following the com p letion of the stakeholder process outlined in this docum ent.

Although the Agency has not yet considered the cum u lative risk for the triazines, the Agency is issuing this interim assessm ent now in order to identify risk reduction m easures that are necessary to support the continued use of atrazine. Based on its current evaluation of atrazine alone, the Agency has determ ined that atrazine products, unless labeled and used as specified in this docum ent, would present risks inconsistent with FIFRA. Accordingly, should a registrant f a il to im plem ent any of the risk m itigation m easures identif ied in this docum ent, the Agency m a y take regulatory action to address the risk concerns from use of atrazine.

At the tim e that a cum u lative assessm ent is conducted, the Agency will address any outstanding risk concerns. For atrazine, if all changes outlined in this docum ent are incorporated

into the labels and the Mem o randum of Agreem en t is im plem ented, then all currently identified

risks will be m itigated. However, because this is an interim RED, the Agency m a y take any

75necessary f u rther actions to f i nalize the reregistration eligibility decision f o r atrazine af ter assessing the cum u lative risk of the triazine class. Such an increm ental approach to the reregistration process is consistent with the Ag ency’s goal of im proving the transparency of the reregistration and tolerance reassessm ent processes. By evaluating each triazine in turn and identifying appropriate risk reduction m easures, the Agency is addressing the risks from use of

all of the triazines in as tim ely a m a nner as possible.

Because the Agency has not yet considered cum u lative risk for all of the triazines, this reregistration eligibility decision does not f u lly satisf y the reassessm ent of the existing atrazine food residue tolerances as called for by the Food Quality Protection Act (FQPA). W h en the Agency has com p leted the cum u lative assessm ent, atrazine tolerances will be reassessed. At that

tim e, the Agency will reassess atrazine along with the other triazine pesticides to com p lete the FQPA requirem e nts and m a ke a f i nal reregistration eligibility determ ination f o r atrazine. By publishing this interim decision on reregistration eligibility and requesting m itigation m easures now for the individual chem ical atrazine, th e Agency is not deferring or postponing FQPA requirem e nts; rather, EPA is taking steps to a ssure that uses that exceed FIFRA’s unreasonable

risk standard do not rem a in on the label longer than is necessary, pending com p letion of the

cum u lative assessm ent required under FQPA. This decision does not preclude the Agency from

m a king further FQPA determ inations or tolerance-related rulem a kings that m a y be required on this pesticide or any other in the future.

If the Agency determ ines, before finalization of the interim RED, that any of the

determ inations described in this interim RED are no longer appropriate, the Agency will pursue appropriate action, including, but not lim ited to, r econsideration of any portion of this interim

RED.

Label changes that are necessary to adequately m itigate the risks of atrazine use are

described in Section V of this docum ent. Appe ndix A sum m a rizes the uses of atrazine that are eligible for reregistration. Appendix B identifies the generic data requirem e nts that the Agency reviewed as part of its determ ination of reregistration eligibility, and lists the subm itted studies that the Agency found acceptable.

B. Summary of Phase 5 Comments and Responses

W h en m a king its interim reregistration decision, the Agency took into account all

com m e nts received during Phases 3, 4, and 5 of the Public Participation Process for atrazine.

These com m e nts are available in the docket in their entirety. Num e rous letters were received

com m e nting on the atrazine risk assessm ents during Phase 5 of the public process. Com m e nts
that addressed hum an health and ecological concerns were received from the technical registrants (Syngenta Crop Protection, Inc., and Si pcam Agro USA); state and other regulatory agencies (California Departm e nt of Pesticide Regulation, California Regional W a ter Quality Control Board, State of New York Office of the Attorney General, Connecticut Office of the Attorney General,U.S. Departm e nt of the Interior, Fish and W ildlife Service); environm ental and advocacy groups (Natural Resources Defense C ouncil [NRDC], People for the Ethical Treatm e nt
of Anim als, Beyond Pesticides/NCAMP, Center fo r Regulatory Effectiveness; universities (Yale

76University; Texas Tech University; U.C. Berkeley); grower and agricultural advocacy groups (National Agricultural Aviation Association, Suga r Cane Growers Cooperative of Florida, W eed Science Society of Am erica, Triazine Netw ork, Marion County Farm Bureau, Am erican Farm Bureau Federation, Illinois Farm Bureau, Louisiana Farm Bureau Federation, Ohio Farm Bureau Federation, Minnesota Farm Bureau); water advocacy groups (Am e rican W a ter W o rks Association); and m a ny private citizens and grow ers. Com m e nts were received on the following topics:

• T oxicology and Mode of Action of Atrazine and Endpoints Chosen;

• C arcinogenicity of Atrazine;

• E cological Risks of Atrazine;

• E xposure to Atrazine and its Degradates;

• O ther Atrazine Regulations;

• O ccupational and Residential Exposure to and Risk from Atrazine;

• A trazine Treatm e nt Costs; and

• B enefits of the Use of Atrazine.

These com m e nts have been addressed and the assessm ents refined as appropriate by the Agency. Response to Com m e nts docum ents addressing m o st of these com m e nts are available in the public docket and on the Agency’s web page at http://www.epa.gov/pesticides/reregistration.

Three com m e nts that were received are being addressed in the IRED, as follows:

com m e nts from the The New York State Office of the Attorney General (NYOAG) on the Endangered Species Act (ESA) and consultations with the U.S. Fish and W ildlife Service (FW S ); com m e nts from the Natural Resources Defense Council (NRDC) on the consideration of

farm worker children in the assessm ent; and com m e nts from the Center for Regulatory Effectiveness on the new Data Quality Act (DQA)

Com m e nt: T he NYOAG com m e nted to the Agency that EPA m u st initiate consultations with

the FW S because EPA’s issuance of a reregistration decision for atrazine triggers the ESA consultation requirem e nt and stated that the ESA requires that the Agency consider any existing FW S biological opinion.

Response: Atrazine has been reviewed on several occasions by the FW S as described in Section III above under the discussion on endangered species. Currently, the Agency is developing a proposal to im plem ent its Endangered Species Protection Program (ESPP). The Agency is soliciting public opinion on this proposal through issuance of a Federal Register Notice, Endangered Species Protection Program Field Im plem entation, Decem ber 2, 2002. The Agency obtained input on several key aspects of the program in a workshop held in Septem ber 2002 that included the pesticide industry, pesticide user groups, and environm ental advocacy organizations. An Advance Notice of Proposal Rulem a king (ANPR), Endangered Species and Pesticide Regulation, was issued jointly by the Agency, the Departm e nt of Interior and the Departm e nt of Com m e rce on January 24, 2003. The ANPR is soliciting com m e nts regarding m e thods to m a ke the consultation

77process m o re efficient.

Com m e nt: T he Center for Regulatory Effectiveness com m e nted on Novem b er 25, 2002, requesting correction under the Environm ental Protection Agency’s (EPA)

Inf o rm ation Quality Guidelines. This Request f o r Correction was f iled on behalf of the Kansas Corn Growers Association, the Triazine Network, and the Center for Regulatory Effectiveness. The com p laint alleges that the April 22, 2002,

Environm ental Risk Assessm ent for Atrazine does not com p ly with the “Data Quality Act” because the docum ent “states that atrazine causes endocrine effects in various organism s including frogs.” The com m e nt requests that the

environm ental risk assessm ent be corrected to state that there is no reliable

evidence that atrazine causes “endocrine effects” in the environm ent and that there can be no reliable, accurate or useful inform ation regarding atrazine’s

endocrine effects until and unless there are test m e thods for those effects that have been properly validated.

Response: After reviewing the questions raised in the request, the Agency has decided that

som e m i nor clarifications of the April 2002 Environm ental Risk Assessm ent for

Atrazine m a y help to avoid any future m i sunderstanding of the Agency’s position

on the environm ental ef f

ects of atrazine. Any such clarif ications will be included

in a revised Environmental Risk Assessment for Atrazine

. This Request for Correction is further addressed in the Agency’s Response to Com m e nts docum ent available in the public docket and on the Agency’s web page at http://www.epa.gov/pesticides/reregistration.

The Agency is providing a 60-day public com m e nt period on this IRED. W h ile all

com m e nts are welcom e, those with specific data or inform ation bearing on the risk and benefit

assessm ents are m o st useful.

C. Regulatory Position

1. FQPA Assessment

a. “Risk Cup” Determination

As part of the FQPA tolerance reassessm ent process, EPA assessed the risks associated

with this triazine. The assessm ent was f o r this individual triazine, and does not attem p t to f u lly reassess these tolerances as required under FQPA. FQPA requires the Agency to evaluate food

tolerances on the basis of cum u lative risk from substances sharing a com m on m e chanism of toxicity, such as the toxicity expressed by the triazine pesticides through a com m on biochem i cal

interaction. The Agency will evaluate the cum u lative risk posed by the entire class of triazines once the policy concerning cum u lative assessm ents is fully resolved.

EPA has determ ined that risk from exposure to atrazine exceeds its own “risk cup” for the currently registered uses of atrazine. In reaching this determ ination, EPA has considered the

78available inf o rm ation on the special sensitivity of inf a nts and children, as well as dietary (f ood and drinking water) and residential exposure to atrazine. However, if the use of atrazine is

m odified, the Mem o randum of Agreem ent is im plem ented, and any other m itigation m easures outlined in this docum ent are im plem ented, the Agency believes that risks f r om the use of atrazine will not exceed the Agency’s level of con cern (i.e., atrazine uses will “fit” within its risk cup). Theref ore, the atrazine tolerances can rem a in in ef f

ect until a f u ll reassessm ent of the

cum u lative risk f r om all triazines is com p leted.

b. Tolerance Summary

Tolerances for residues of atrazine per se are established under 40 CFR §180.220(a)(1).

Tolerances for atrazine and its chlorinated m e tabolites are established under 40 CFR §180.220(a)(2).

The Agency has determ ined that the tolerance expression in 40 CFR §180.220(a)(1)

m u st be changed to ref l ect the com b ined residues of atrazine and its chlorinated m e tabolites, and

that all tolerances based on atrazine and its chlorinated m e tabolites should be placed together under 40 CFR § 180.220 (a)(1). A sum m a ry of atrazine tolerance reassessm ents is presented in

Table 28. Reassessm ents are based on tolerances redefined as atrazine and its chlorinated

m e tabolites.

The Agency has also determ ined that tolerance expressions for the com b ined residues of each of the four hydroxy com pounds are not needed.

The Agency will com m e nce proceedings to revoke and m odify existing tolerances, and to

correct com m odity definitions. The establishm ent of a new tolerance or raising tolerances will be deferred, pending consideration of cum u lative risk for the triazines. “Reassessed” does not

im ply that all of the tolerances have been fully reassessed as required by FQPA, since these

tolerances m a y only be fully reassessed once the cum u lative risk assessm ent of all triazine pesticides is considered, as required by the statute. Rather, this IRED provides reassessed

tolerances for atrazine in/on various com m odities, supported by all the subm itted residue data, only f o r atrazine. EPA will f i nalize these tolerances af ter considering the cum u lative risks f o r all triazine pesticides. The Agency’s tolerance sum m a ry is provided in Table 28.

Tolerances Listed Under 40 CFR §180.220(a)(1)

Tolerances for residues in/on sweet corn forage and fodder can be lowered to 4.0 ppm and 2.0 ppm , respectively, to 1.5 ppm for field/pop corn forages, and to 0.5 ppm for field/pop corn fodder and the designation “fodder” should be revised to “stover.” The tolerances for residues in/on corn, fresh, K+CW HR and corn grain can be decreased to 0.20 ppm , each based

on com b ined nondetectable residues at 0.05 ppm for atrazine and each chloro-m etabolite. The

tolerance for residues in/on m acadam ia nuts can be lowered to 0.20 ppm based on com b ined nondetectable residues at 0.05 ppm for atrazine and each chloro-m etabolite. Tolerances for residues in/on sorghum forage and fodder can be lowered to 0.50 ppm , each; the designation

“fodder” should be revised to “stover.” The tolerance for residues in/on sorghum grain can be

79lowered to 0.20 ppm based on com b ined nondetectable residues at 0.05 ppm for atrazine and

each chloro-m etabolite. The tolerances for residues in/on wheat fodder, grain, and straw can be lowered to 1.5, 0.10, and 0.50 ppm , respectively; the designation “fodder” should be revised to “forage.” The tolerance for sugar cane can be lowered to 0.20 ppm based on com b ined nondetectable residues at 0.05 ppm for atrazine and each chlorinated m e tabolite. The tolerances for residues in/on sugarcane, forage and fodder, should be revoked, as these are no longer regulated as livestock feed item s

. The tolerance for residues in/on guavas is adequate.

Existing tolerances f o r residues in com m odities f r om cattle, goats, horses, and sheep (0.02 ppm ) m u st be increased to 0.10 ppm include com b ined residues of atrazine and chlorinated

m e tabolites. Tolerances have been reassessed based on anim al feeding study data.

The tolerances for com m odities from hogs, poultry, and eggs can be revoked as there is no reasonable expectation of finite residues.

Syngenta proposes lowering the tolerances for sweet and field corn forages to 1.5 ppm

, and the tolerance for sorghum forage to 0.25 ppm

. For postem e rgent treatm e nts, the registrant proposes a change from a 30-day PHI to a 45-day PHI for sweet corn and sorghum forages, and

from a 30-day PHI to a 60-day PHI for field corn forage. For preem ergent treatm e nts on sorghum , they propose a change from a 45-day PHI to a 60-day PHI. Preem ergent treatm e nts on
sweet and f i eld corn will retain the existing 45-day and 60-day PHI, respectively. Existing labels contain 21 and 30-day PHIs for corn and sorghum forages.

The Agency has reassessed the tolerance for sweet corn forages at 4.0 ppm based on field trial data showing the highest chlorotriazine re sidues detected at 3.2 ppm after one treatm e nt, and a 30-day PHI. Syngenta states that a sweet corn forage tolerance of 1.5 ppm is supported by data representing a 45-day PHI. Maxim u m chlorotriazine residues on sweet corn forage harvested 45 days after postem e rgent treatm e nts at the 1X rate expected to result in the highest residues (0.5 +

2.0 lbs ai/A) were approxim a tely 1.15 ppm

. The Agency concludes that if labels for

postem e rgent sweet corn use are am ended to allow a m i nim u m PHI of 45 days, the tolerance for sweet corn forage be lowered to 1.5 ppm

.

The Agency has already reassessed the tolerance for field corn forage at 1.5 ppm based on the highest chlorotriazine residues detected at 1.1 ppm after a 1X treatm e nt, at either a 30-day or a 60-day PHI. Maxim u m chlorotriazine residue s on field corn forage harvested 60 days after

postem e rgent treatm e nts at the 1X rate expected to result in the highest residues (0.5 + 2.0 lbs ai/A) were approxim a tely 1.11 ppm

. The Agency concludes that all atrazine labels for

postem e rgent field corn should be am ended to allow a m i nim u m PHI of 60 days.

The tolerance for sorghum forage has already been reassessed at 0.5 ppm based on field trial data showing the highest chlorotriazine re sidues detected at 0.22 ppm after a 1X treatm e nt, and a 23-day PHI. Maxim u m chlorotriazine residues on sorghum forage harvested 30 and 45 days after postem e rgent treatm e nts at the 1X rate were approxim a tely 0.35 ppm and 0.09 ppm

, respectively. Maxim u m chlorotriazine residues on sorghum forage harvested 45 and 60 days after preem ergent treatm e nts at the 1X rate were approxim a tely 0.12 and 0.16 ppm , respectively.

80The Agency concludes that if all atrazine labels for postem e rgent sorghum use are am ended to

allow a m i nim u m PHI of 45 days, and for preem ergent sorghum use to allow a m i nim u m PHI of 60 days, the tolerance for sorghum forage be lowered to 0.25 ppm

.

The Agency has recalculated the m a xim u m theoretical dietary burden (MTDB) for dairy cattle based on a reassessed sweet corn forage tolerance of 1.5 ppm

. The resulting MTDB for dairy cattle is approxim a tely 2.0 ppm chlorotriazines. Extrapolating the results from cattle feeding studies to this MTDB results in a rea ssessed m ilk tolerance of 0.03 ppm

. If all atrazine

labels are am ended to the proposed PHIs discussed above for sweet and field corn forage and sorghum forage, the m ilk tolerance can be lowered to 0.03 ppm , based on available feeding

studies and residue data.

Tolerances Needed Under 40 CFR §180.220(a)(1)

The Agency proposes establishing a tolerance for residues of atrazine and the chlorinated

m e tabolites in wheat hay based on existing wheat forage residue data, and taking into account any concentration of residues during drying proce sses for hay. Alternatively, the registrant m a y subm it f i eld trials to determ ine an appropriate tolerance level f o r residues in/on wheat hay.

An additional processing study is required for sugarcane, in order to determ ine the need for a separate tolerance for residues in m o lasses.

Tolerances Currently Listed Under 40 CFR §180.220(a)(2) To Be Placed Under 40 CFR §180.220(a)(1)

The Agency recom m e nds that the established tolerances for residues of atrazine in or on orchard grass and orchard grass, hay be revoked, as these uses are not being supported. The Agency also recom m e nds the revocation of the 15 ppm tolerance for Perennial rye grass and

that the use be cancelled. In addition, the tolerance for Grass, range should be revoked and a crop group tolerance for Crop Group 17 (Grass, Forage, Fodder, and Hay) should be established under 180.220(a)(1), that will cover range grasses. Residue data on representative grasses to support the crop group tolerance are recom m e nded. This will include residue data on berm uda grass, bluegrass, and brom egrass or fescue from 12 trials (four for each cultivar) conducted in

concordance with the current label rates. If the registrant(s) do not wish to support a crop group tolerance with new residue data, the existing tolerances should be revoked and the uses

cancelled.

Table 28. Tolerance Reassessment Summary for Atraz i ne

Commodity Esta blished Tolerance, ppm Reassessed Tolerance, ppm Comments [ Co rrect Co mmo d ity Definitio n ]

T o l erances L i sted Under 40 CFR §180.220(a)(1) 1

81Table 28. Tolerance Reassessment Summary for Atraz i ne

Commodity Esta blished Tolerance, ppm Reassessed Tolerance, ppm Comments [ Co rrect Co mmo d ity Definitio n ]

Cattle, fat 0 .0 2 0 .1 0 Reassessed tolerances based on reassessed sweet corn forage t o l e rance of 4.0 ppm

. R e gi st rant

recom m e nded lowering tolerances for sweet corn forage t o 1.5 ppm pendi ng am endm ent of al l atrazine labels for postem e rgent sweet corn use to
al l o w a m i ni m u m PHI of 45 day s

. Cattle, m b yp 0

. 0 2 0

. 1 0

Cattle, m eat 0

. 0 2 0

. 1 0

C o rn, fodder, fi el d 1 5 0 .5 co rn , field , sto ver

C o rn, fodder, pop 15 0.5 corn, pop, st over

C o rn, fodder, sweet 15 2.0 corn, fresh, stover

Corn, forage, field 1 5 1 .5 Am en d all atrazin e lab e ls fo r p o s tem e rg en t an d

preem ergent fi el d corn use t o requi re a m i ni m u m PHI of 60-day s

.
C o rn, forage, pop 15 1.5

Corn, forage, sweet 15 1.5 Am en d all atrazin e lab e ls fo r p o s tem e rg en t an d

preem ergent sweet corn use to require a m i nim u m PHI of 45 day s

. Corn, fresh,

K+CW HR 0.25 0.20

Corn, grain 0 .25 0 .20

Eggs 0.02 R e voke The Agency concludes that there is no reasonable

expect at i on of fi ndi ng quant i f i a bl e at razi ne resi dues i n eggs or t h e m eat , fat

, or m eat by product s of poul t r y

Goats, fat 0 .02 0 .10 Reassessed tolerances based on reassessed sweet corn forage t o l e rance of 4.0 ppm

. R e gi st rant

recom m e nded lowering tolerances for sweet corn forage t o 1.5 ppm pendi ng am endm ent of al l atrazine labels for postem e rgent sweet corn use to
al l o w a m i ni m u m PHI of 45 day s

. Goat s, m b y p 0.02 0.10

Goat s, m eat 0.02 0.10

Guava 0 .05 0 .05

Hogs, fat 0 .02 R evoke No reasonabl e expect at i on of fi ndi ng quant i f i a bl e atrazine residues in the m eat, fat, or m eat by product s of hogs. Hogs, m b y p 0.02 R e voke

Hogs, m eat 0.02 R e voke

Horses, fat 0 .02 0 .10 Reassessed tolerances based on reassessed sweet corn forage t o l e rance of 4.0 ppm

. R e gi st rant

recom m e nded lowering tolerances for sweet corn forage t o 1.5 ppm pendi ng am endm ent of al l atrazine labels for postem e rgent sweet corn use to
al l o w a m i ni m u m PHI of 45 day s

. Horses, m b y p 0.02 0.10

Horses, m eat 0.02 0.10

Macadam ia nuts 0 .25 0 .20

M i l k 0.02 0.03 Al l at razi ne l a bel s m u st be am ended t o t h e proposed PHIs for sweet and fi el d corn forage and sorghum forage.

82Table 28. Tolerance Reassessment Summary for Atraz i ne

Commodity Esta blished Tolerance, ppm Reassessed Tolerance, ppm Comments [ Co rrect Co mmo d ity Definitio n ]

Poul t r y , fat 0 .02 R evoke The Agency concludes that there is no reasonable

expect at i on of fi ndi ng quant i f i a bl e at razi ne resi dues i n eggs or t h e m eat , fat

, or m eat by product s of poul t r y

. Poul t r y , m b y p 0.02 R e voke

Poul t r y , m eat 0.02 R e voke

Rye, grasses, perenni al 15 R e voke Uses are restricted to the Conservation Reserve Program (CRP) lands in OK, OR, NE, and TX.

R e st ri ct i ons on grazi ng and cut t i ng for hay appl y

.

Sheep, fat 0 .02 0 .10 Reassessed tolerances based on reassessed sweet corn forage t o l e rance of 4.0 ppm

. R e gi st rant

recom m e nded lowering tolerances for sweet corn forage t o 1.5 ppm pendi ng am endm ent of al l atrazine labels for postem e rgent sweet corn use to
al l o w a m i ni m u m PHI of 45 day s

. Sheep, m b y p 0.02 0.10

Sheep, m eat 0.02 0.10

Sorghum , fodder 1 5 0 .50 Sorghum, st over

Sorghum , forage 15 0.25 Am end al l at razi ne l a bel s for post e m e rgent sorghum use t o requi re a m i ni m u m PHI of 45 day s , and for preem ergent sorghum use t o requi re

a m i ni m u m PHI of 60 day s

. Sorghum , grai n 0 .25 0 .20

Sugarcane 0 .25 0 .20

Sugarcane, fodder 0 .25 R evoke Not a si gni fi cant l i v est o ck feed i t e m
Sugarcane, forage 0.25 R e voke Not a si gni fi cant l i v est o ck feed i t e m

W h eat , fodder 5 1.5 Wheat, forage

W h eat, grain 0 .25 0 .10

W h eat , st raw 5 0.50

T o l erances L i sted Under 40 CFR §180.220(a)(2) T o be Pl aces Under 40 CFR §180.220(a)(1) 1

Grasses, orchardgrass 15 R e voke Uses on orchard grass are not support e d by t h e basi c produce

Grasses, orchardgrass, hay 15 R e voke Uses on orchard grass are not support e d by t h e basi c producer

83Table 28. Tolerance Reassessment Summary for Atraz i ne

Commodity Esta blished Tolerance, ppm Reassessed Tolerance, ppm Comments [ Co rrect Co mmo d ity Definitio n ]

Grasses, range 4 T BD Uses are restricted to the Conservation Reserve Program (CRP) lands in OK, OR, NE, and TX.

R e st ri ct i ons on grazi ng and cut t i ng for hay appl y

. However, t h ese grasses m a y be fed duri ng drought

and em ergenci e s. R e gi st rant m a y est a bl i s h a crop

group t o l e rance under C r op Group 17. R e si due data on representative crops are recom m e nded.

Once data are subm itted a crop group tolerance

shoul d be est a bl i s hed under 180.220(a)(1). Tabl e 2 of OPPTS 860.1500 C r op Fi el d Tri a l s cal l s for 12 trials (four for each cultivar). Existing

t o l e rances are bel i e ved t o be unsupport a bl e based

on t oday ’ s dat a requi rem e nt s. If t h e regi st rant (s)

do not wi sh t o support a crop group t o l e rance wi t h

n e w resid u e d a ta, th e ex istin g to leran ces will b e revoked and t h e uses cancel l e d.

T o l erances Needed Under 40 CFR §180.220(a)(1) 1

Sugarcane m o l a sses none TB D 2 Ad d itio n a l d a ta are req u i red to d e term in e th e n eed for a separate tolerance.

W h eat , hay none 5 Thi s t o l e rance i s based on resi due dat a for wheat forage, t a ki ng i n t o account concent r at i on of

resid u e s as fo rag e is d r ied to h a y. Altern ativ ely,

t h e regi st rant s m a y provi de resi due dat a on wheat

h a y fro m field trials.

T o l erances to be Proposed Under 40 CFR §180.220(d)

[Indi rect resi dues i n fol i a ge of l e gum e veget a bl es] none TB D Ad d itio n a l d a ta are req u i red to d e term in e th e n eed for indirect residue tolerance(s).

1 T o ler a nces r eassessed based on com b ined r e sidues of atr azine, G30033, G- 28279, and G- 28273.

2 TBD = To be determ ined. Reassessm ent of tolerance(s) cannot be m a de at this tim e because additional data are required.

3 T o ler a nces based on com b ined r e sidues of 2- hy dr oxy

- 4

- e thy l am ino- 6- isopr opy lam i no- s- tr iazine ( G

- 34048)

, 2- am ino- 4- hy dr oxy

- 6

­ isopr opy lam i no- s- tr iazine ( G S- 17794)

, 2- am ino- 4- hy dr oxy

- 6

- e thy l am ino- s- tr iazine ( G S- 17792)

, and 2, 4- diam ino- 6- hy dr oxy

- s

tr iazine ( G S- 17791)

.

3. Codex Harmoniz ation

The Codex Alim entarius Com m i ssion has not proposed or established m a xim u m residue

lim its (MRLs) f o r residues of atrazine in/on agricultural com m odities. Theref ore, there are no issues regarding harm onization or com p atibility of U.S. tolerances with Codex MRLs.

4. Endocrine Disruptor Effects

EPA is required under the FFDCA, as am ended by FQPA, to develop a screening

program to determ ine whether certain substances (including all pesticide active and other ingredients) “m ay have an effect in hum ans that is sim ilar to an effect produced by a naturally occurring estrogen, or other such endocrine effects as the Adm i nistrator m a y designate."

84Following the recom m e ndations of its Endocrine Disruptor Screening and Testing Advisory

Com m ittee (EDSTAC), EPA determ ined that there were scientific bases for including, as part of the program , the androgen and thyroid horm one system s, in addition to the estrogen horm one system

. EPA also adopted EDSTAC’s recom m e nda tion that the Program include evaluations of potential effects in wildlife. For pesticide chem icals, EPA will use FIFRA and, to the extent that

effects in wildlife m a y help determ ine whether a substance m a y have an effect in hum ans, FFDCA authority to require the wildlife evaluations. As the science develops and resources allow, screening of additional horm one system s m a y be added to the Endocrine Disruptor Screening Program (EDSP).

W h en the appropriate screening and/or testing protocols being considered under the Agency’s EDSP have been developed, atrazine m a y be subjected to additional screening and/or testing to better characterize effects related to endocrine disruption.

5. Labels

A num ber of label am endm ents, in addition to the existing label requirem e nts, are necessary in order for atrazine products to be eligible for reregistration. The Agency has

determ ined that these m easures, in addition to the existing label requirem e nts, will adequately

reduce risks.

Provided the following risk m a nagem e nt m easures are incorporated in their entirety into labels for atrazine-containing products, the Agency finds that all currently registered uses of atrazine are eligible for interim reregistration, pending consideration of cum u lative risks of the

triazines. W h ile all uses are eligible at this tim e, the cotton use will be phased out over f i ve years. The regulatory rationale for each of the risk m a nagem e nt m easures outlined below is

discussed im m e diately after this list of required risk m a nagem e nt m easures.

a. Agricultural Use Exposure Reduction Measures

For agricultural use, the following m easures are required, in addition to the existing label requirem e nts to address risks of concern.

Dietary (Drinking W a ter)

• R equire the following statem ent:
“ANY USE OF THIS PRODUCT IN AN AREA W H ERE USE IS PROHIBITED

IS A VIOLATION OF FEDERAL LAW

. Before using this product, you m u st
consult the Atrazine W a tershed Inform ation Center (AW I C) to determ ine whether the use of this product is prohibited in your watershed. AW IC can be accessed through [website], [m ailing address] or [1-800-toll-free num ber]. If use of this product is prohibited in your watershed, you m a y return this product to your point of purchase or contact [insert nam e of registrant] for a refund.”

Occupational - Agricultural Uses

851) Mixing/Loading Scenarios: a) Liquids:

• r equire closed system s for m i xing/loading to support aerial applications at greater than 3 lb ai/A

• a ll m i xers/loaders (including using engineering controls) m u st wear longsleeve shirt, long pants, shoes, socks, chem ical-resistant gloves and

chem ical resistant apron b) W e ttable Powders:

• r equire water-soluble packaging for all W P form ulations

• a ll m i xers/loaders m u st wear long-sleeve shirt, long pants, shoes, socks,

chem ical-resistant gloves and chem ical resistant apron c) Dry Flowables:

• w ater-soluble packaging optional

• i f in water-soluble packaging, all m i xers/loaders m u st wear long-sleeve shirt, long pants, shoes, socks, chem ical-resistant gloves and chem ical resistant apron

• i f not in water-soluble packaging, m i xers/loaders m u st wear coveralls over long-sleeve shirt and long pants, chem ical-resistant gloves, chem icalresistant footwear, and chem ical-resistant apron plus a NIOSH-approved

dust/m ist f iltering respirator with any N, R, P, or HE f ilter.

• i f not in water-soluble packaging, aerial application is prohibited. d) Granular Products:

• L oaders m u st wear long-sleeve shirt, long pants, shoes, and socks.

2) Applicator and Flagger Scenarios:

a) Pilots m u st use enclosed cockpits (40 CFR 170.240(d)(6)) for aerial applications. b) Hum a n flaggers supporting aerial applications m u st used enclosed cabs (40 CFR 170.240(d)(5)). c) Applicators applying sprays with m o torized ground equipm ent (i.e., groundboom or rights-of-way sprayers) m u st wear long-sleeve shirt, long pants, shoes, socks,

and chem ical-resistant gloves. d) Applicators applying granular products or im pregnated fertilizer m u st wear longsleeve shirt, long pants, shoes, and socks.

• R estrict the im pregnation of bulk f e rtilizer to com m e rcial f a cilities (prohibit on-farm im pregnation)

• R estrict the im pregnation of dry bulk fertilizer to 500 tons per day for no

m o re than 30 days per calender year per f acility e) Reduce the m a xim u mapplication rate for handlers applying liquids with rightsof-way sprayers to 1.0 lb ai/A f) Reduce the m a xim u m application rate for liquids for chem ical follow to 2.25 lb

ai/A g) Require a 60-day PHI for field corn forage uses h) Require a 45-day PHI for sweet corn forage uses i) Require a 60-day PHI for pre-em ergent uses and a 45-day PHI for postem e rgent

86sorghum forage uses

b. Non-Agricultural Use Exposure Reduction Measures

1) Non-Agricultural Products including Law n s and Turf (not Sod Farms)

a) Require that all wettable powder products be packaged in water soluble bags. b) Granular form ulations: loaders, appli cators, and other handlers m u st wear longsleeve shirt, long pants, shoes, and socks. c) Liquid, wettable powder, dry flowable (water-dispersible granule) form ulations:

• a pplicators using spray equipm ent m ounted on their backs m u st wear coveralls worn over long sleeved shirt and long pants, chem ical-resistant gloves and chem ical-resistant footwear plus socks.

• a ll other m i xers, loaders, applicators, and other handlers m u st wear longsleeved shirt and long pants, shoes and socks, and chem ical resistant gloves.

• R educe the m a xim u m single application rate for liquid form ulations on

residential lawns and turf to 1 lb ai/A from 2 lb ai/A (liquid products containing >4% ai are restricted use) d) Require that granular lawn products be watered in

2) Residential

z) Restrict the application of granular la wn products when using hand-held devices (e.g. belly grinder) to spot applications only. aa) Prohibit applications of granular lawn products by hand bb) Reduce the m a xim u m single application rate for liquid form ulations on residential

lawns and turf to 1 lb ai/A from 2 lb ai/A (liquid products containing >4% ai are restricted use) cc) Require that granular lawn products be watered in

c. Label Harmoniz ation

As described in Section II under the discussi on of the regulatory history of atrazine, a

num ber of risk m itigation m easures have been instituted over the years to address exposure to

atrazine. W h ile m o st product labels have adopted these m easures there are som e that continue to

ref l ect use patterns prior to the im plem entation of these risk m itigation m easures. T he listing

below identifies m easures that are not fully im plem ented on all current product labels. All of

these m easures, in addition to new label requirem e nts as defined by this IRED, are needed on atrazine labels in order for products to be eligible for reregistration.

• A trazine products containing >4% active ingredie nt m u st be classified as restricted use

• M axim um broadcast application rates for corn and sorghum m u st be as follows: a) W h ere both a preem ergence and a postem e rgence are used, the total atrazine

87applied in the preem ergence PLUS postem e rgence treatm e nt cannot exceed 2.5 lb ai/A/calendar year. b) 2.0 lb ai/A as a single preem ergence application on soils that are not highly erodible or on highly erodible soils if at least 30% of the soil is covered with plant residues; or c) 1.6 lb ai/A as a single preem ergence application on highly erodible soils if <30% of the surface is covered with plant residues; or d) 2.0 lb ai/A if only applied postem e rgence. e) For all tank m i xtures and sequential treatm e nt of products containing atrazine, the total lbs. a.i. of atrazine applied cannot exceed the application lim its described

above.

• M axim um application rates per crop m u st be as follows (single application and annual

ma x i mu m) : a) Conifers 4 lb ai/A; 4 lb ai/A per year m a xim u m b) Sugarcane 4 lb ai/A (single application);10 lb ai/A per year m a xim u m c) Rights-of-W ay/Roadsides Treatm e nt 1 lb ai/A; 1 application per year d) Guava 4 lb ai/A (single application); 8 lb ai/A per year m a xim u m e) Macadam ia Nuts 4 lb ai/A (single application); 8 lb ai/A per year m a xim u m f) Conservation Reserve Program (CRP) 2 lb ai/A g) Chem ical Fallow 2.25 lbs ai/Aa

• D elete all uses for total vegetation control on non-cropland areas. This does not include rights-of-way/roadsides or CRP

• P rohibit use in chem igation system s

• P rohibit use, and m i xing and loading within 50 feet of all wells, including abandoned wells, drainage wells, and sink holes

• P rohibit m i xing and loading within 50 f eet of interm ittent stream s and rivers, natural or

im pounded lakes and reservoirs.

• P rohibit application within 66 feet of the points where field surface water runoff enters perennial or interm ittent stream s and rivers. If land is highly erodible, the buf f

e r m u st be planted to the crop or seeded with grass or other suitable crop.

• P rohibit application within 200 feet of natural or im pounded lakes and reservoirs.

• R equire that one of the f o llowing restrictions be used in applying Atrazine to tiledoutletted fields containing standpipes a) Do not apply within 66 feet of standpipes in tile-outletted fields b) Apply this product to the entire tile-outletted field and im m e diately incorporate it to a depth of 2-3 inches in the entire field c) Apply this product to the entire tile-outletted field under a no-till practice only when a high crop residue m a nagem e nt practice is practiced. High crop residue

m a nagem e nt is described as a crop m a nagem e nt practice where little or no crop

residue is rem oved from the field during and after crop harvest.

D. Regulatory Rationale

The following is a sum m a ry of the rationale for m a naging risks associated with the

current uses of atrazine. The Agency has discussed these m easures with the technical registrants

88and in all cases the registrants have agreed to the m easures presented here. W h ere labeling revisions are warranted, specific language is set forth in the sum m a ry tables of Section V of this

docum ent.

1. Human Health Risk Mitigation

a. Dietary (Food)

The acute and chronic dietary risks from atrazine residues on food are well below the Agency’s level of concern at the 99.9th percentile of exposure. Therefore, no m itigation

m easures are necessary at this tim e.

b. Dietary (Drinking Water)

1) Community Water Systems (CWS)

The Agency has identified 34 surface water CW S with levels of atrazine that have exceeded the Agency’s current DW LOC (12.5 ppb as a 90-day average) at least once since frequent m onitoring for atrazine began in 1993. The 12.5 DW LOC was used as a screening tool to identify specific CW S that were of concern to the Agency. The registrant has since added 3

CW S to the list of CW S of concern. These 37 CW S have been targeted for intensive m onitoring,

risk m itigation, and probabilistic risk assessm ents.

The 12.5 ppb DW LOC was also used as a tool to establish a trigger value based on

SDW A com p liance m onitoring data by which CW S with potential high-end seasonal exposures

could be identified in the future. The Agency considered available data from SDW A com p liance

m onitoring and determ ined that a trigger value of 2.6 TCT provides an appropriate early warning. If annual average concentrations of atrazine and its chlorinated m e tabolites (total chlorotriazines - TCT) in a surface water CW S reach 2.6 ppb, this triggers weekly (during the use season) and biweekly (during the rem a inder of the year) m onitoring of that CW S for TCT

concentrations.

The 12.5 ppb DW LOC is based on an endpoint of 1.8 m g /kg/day and a 1000 fold uncertainty factor. The uncertainty factor incl udes a 10x factor for interspecies variation; a 10x factor for intraspecies variability, and a 10x FQPA Safety Factor. The 10x FQPA safety factor was applied to account for the uncertainties associated with atrazine’s toxic effects on the developing child and the extent and m a gnitude of exposure to atrazine in drinking water.

Com m unity water system s found to be potentially im paired by atrazine, as predicted by exceedences of an annual average of 2.6 ppb based on SDW A com p liance m onitoring data, and

the 37 CW S identified above will be subject to an intensive m onitoring program that includes weekly sam p ling for atrazine during the use season and biweekly sam p ling for atrazine during

the rem a inder of the year. This m onitoring program will determ ine the m a xim u m 90-day average TCT concentration with sufficient accuracy to allow rem oval of that portion of the 10x FQPA safety factor associated with residual uncertainties regarding the extent and m a gnitude of

89drinking water exposure, thereby reducing the 10x FQPA safety factor to 3x for the risk

assessm ents conducted in those com m unity water system s for which there is available, reliable drinking water exposure data.

For those specific CW S undergoing or preparing to undergo intensive m onitoring, uncertainties regarding the extent and m a gnitude of exposure to chlorotriazines no longer exist; this supports a reduction in the FQPA safety factor to 3x for those CW S. Based on this, the Agency has recalculated the DW LOC using a total risk assessm ent 300x uncertainty factor for

those CW S currently undergoing or targeted for future intensive m onitoring. For these CW S, the

DW LOC becom e s 37.5 ppb for total chlorotriazines based on an endpoint of 1.8 m g /kg/day, and a 300x uncertainty factor reflecting a 10x factor for interspecies variation, a 10x factor for intraspecies variability, and a 3x FQPA saf e ty f actor. The 3x FQPA saf e ty f actor ref l ects
residual uncertainties associated with atrazine’s toxic effects on the developing child only. For

CW S without intensive m onitoring as described above, the screening level DW LOC rem a ins

12.5 ppb for total chlorotriazines.

As such, the Agency is establishing 37.5 ppb TCT (as a 90-day average) as a perform a nce standard that m u st be m e t in CW S that are being intensively m onitored. The Agency believes that its usual m itigation m easures for pesticide chem icals (e.g., reduction in label rates, labeled use restrictions, etc.) are not appropriate in the case of atrazine because of the

nature of the chem ical. Exceedences do not appear to be linked to nation-wide use practices that

can be am ended on the label. Based on atrazine m onitoring data, the Agency’s risk assessm ent
for atrazine has determ ined that drinking water risks from atrazine use are localized problem s and, as such, lend them selves to a localized m itigation plan. In addition, this localized approach

is consistent with the conclusions from a February 2000 FIFRA Scientific Advisory Panel

m eeting (Partial Report May 25, 2000. Report Num b er 2000-01). OPP’s approach is also consistent with the intent of the Agency’s recent January 2003 W a ter Quality Trading Policy that encourages solutions within watersheds, provides incentives and encourages actions, and provides flexibility to m eet local challenges and accountability to ensure im provem e nts.

The Agency’s approach to these CW S is as follows:

• F or 2 CW S that were identified in the screening-level assessm ent and are of concern to the Agency, Shipm a n, IL, and Hettick, IL, the Agency understands that these CW S will no longer be using the reservoir that has shown unacceptable atrazine levels as a water

source f o r the com m unity in the f u ture.

• F or 8 CW S that were identified in the screening-level assessm ent (see Appendix H for a site-specific listing), the Agency is requiring frequent m onitoring data. If an exceedence of 37.5 is detected in raw drinking water (pre-treatm e nt) in any of these watersheds,

f u rther use of atrazine will be prohibited in that watershed.

• F or all rem a ining CW S, the Agency is requiring frequent m onitoring data if an annual average of 2.6 total chlorotriazines is triggered through SDW A com p liance m onitoring

data. If an exceedence is detected in raw drinking water (pre-treatm e nt) twice in any

90watershed, f u rther atrazine use will be prohibited in that watershed.

• F requent m onitoring will continue annually for five years (m inim um ) and m a y only cease if no 90-day rolling average exceeds the perform a nce standard of 37.5 ppb total chlorotriazines during the five year period.

Based on the m onitoring program s, the registrants are being required to subm it annual reports to the Agency that include the results of that year’s analysis. Atrazine registrants m u st notify EPA in writing of any raw water exceedance within 30 days of date of the last water

sam p le included in that result.

As part of the Agency’s m itigation program f

o r atrazine, registrants are also being required to subm it to the Agency written m itigation plans f o r the 8 CW S of concern (or any other

CW S that has an exceedence in the future) describing m itigation m easures to be im plem ented and a strategy for com m unication with growers within the watershed and quarterly progress reports describing the m easures taken during that quarter in each CW S.

An im portant elem ent of the m itigation program is the ability of the Agency to quickly prohibit use of atrazine in watersheds that have exceeded the applicable perform a nce standard. This is possible because the m itigation program includes a m echanism that does not require lengthy adm i nistrative proceeding before the use prohibition goes into effect. The principle registrants of atrazine have agreed to this m easure. W ithout this voluntary m e asure, it m a y have been necessary for the Agency to seek im m e diate cancellation of atrazine.

In order to im plem ent this agreem ent, if the product contains directions for use other than

for reform ulation and contains greater than 4% atrazine active ingredient, the label m u st include

all of the f o llowing statem ents:

“ANY USE OF THIS PRODUCT IN AN AREA W H ERE USE IS PROHIBITED

IS A VIOLATION OF FEDERAL LAW

. Before using this product, you m u st
consult the Atrazine W a tershed Inform ation Center (AW I C) to determ ine whether the use of this product is prohibited in your watershed. AW IC can be accessed through [website], [m ailing address] or [1-800-toll-free num ber]. If use of this product is prohibited in your watershed, you m a y return this product to your point of purchase or contact [insert nam e of registrant] for a refund.”

91The atrazine registrants will establish an Atrazine W a tershed Inf o rm ation Center (AW I C)

that:

• w ill provide detailed inf o rm ation on what W a tershed Areas have becom e subject to a prohibition on Atrazine use. Only inform ation approved by EPA m a y be

included in the AW IC.

• s hall be accessible to the public daily, including weekends and holidays, through a toll-free telephone num ber available 24 hours a day and seven days a week, a

W o rld W i de W e b site, and a regular m a iling address. Contact inform ation for the

AW IC will be included on all Atrazine product labels.

• s hall be updated to include any W a tershed Areas for which use is prohibited

• w ill prom inently display inf o rm ation regarding use prohibitions in a m a nner that

is sim p le and convenient for users to access and understand.

This localized drinking water m itigation program will ensure that m itigation actions

taken in watersheds of concern are providing results in raw drinking water and will prevent any

exceedences from occurring or going undetected in the future. The Mem o randum of Agreem ent with the atrazine technical registrants provides f u rther details on this m itigation plan, including the specifics of the m onitoring program s being established and the m echanism by which use prohibitions will be im plem ented.

This program allows the Agency to m a ke a safety finding because future exceedences in raw water trigger use prohibitions in the watershed of concern. Since this exceedence is in raw, not finished water, treatm e nt of water by CW S operators to m eet the MCL m a y prevent actual exposures above the Agency’s level of concern. In addition, the Agency does not expect future exceedences to occur because of the responsible use program s being im plem ented and coordinated by the registrants as product stewards hip. The Agency feels that the risk of use prohibitions is a strong incentive for atrazine users and the registrants to m a ke every effort to prevent exceedences. The perform a nce standard approach m a kes the prevention of atrazine

water contam ination the responsibility of the user, but will not result in unacceptable risks.

2) Rural Drinking Water Wells

To confirm that rural drinking water wells will not have atrazine levels that exceed the Agency' s level of concern, the Agency will be requiring that the registrant(s) develop and conduct a program for the m onitoring of rural wells. The Agency is requiring that the registrants define a protocol for m onitoring total chlorotriazine levels in rural wells by April 30, 2003. The protocol m u st identify the num ber of wells to be sam p led, the frequency of m onitoring, the

duration and tim ing of m onitoring, and the tim ing of subm ission of data. The Agency m a y take appropriate regulatory action if EPA determ ines that additional label restrictions for the protection of rural drinking water wells are necessary.

b. Residential Risk Mitigation

921) Residential Handler Risk

Residential handler risks were considered for hom eowners who m i x, load, and apply atrazine products to hom e lawns.

One residential handler risk scenario was above the Agency’s level of concern, the broadcast application of granular form ulations w ith a bellygrinder. To address these concerns,

the f o llowing risk m itigation m easures are needed in order f o r EPA to conclude that atrazine products are eligible for reregistration:

• R estrict the application of granular lawn products when using hand-held devices to spot applications only.

• P rohibit applications of granular lawn products by hand.

2) Residential Post-Application Risk

Residential post-application risks were considered for individuals that reenter lawns and golf courses treated with atrazine.

The Agency has risk concerns for incidental oral exposures in children to atrazine

residues. For lawns treated with liquid form ulations of atrazine, the Agency has concerns for

hand-to-m outh exposures alone (MOE = 210) and for com b ined oral routes of exposure (handto-m outh, turfgrass & object m outhing, and ingestion of soil; MOE = 200). For lawns treated with granular form ulations, the Agency has c oncerns for incidental ingestion of granules.

To address those concerns, the risk m itigation m easures listed below are necessary.

These m itigation m easures m a ke it possible for EPA to conclude that atrazine products are eligible for reregistration. The m itigation m easures are as follows:

• R educe the m a xim u m 1 tim e application rate for liquid form ulations on lawns and

turf to 1 lb ai/A f r om 2 lb ai/A.

• R equire that granular lawn products be watered in.

At the 1 lb ai/A rate for liquid form ulations of atrazine, the short termMOE for hand-tom outh and com b ined incidental oral exposures becom e s acceptable individually (420 and 370, respectively). If granular lawn products are watered in, the short-term MOE for ingestion of granules is no longer appropriate since the individual granules will no longer be present in the

turf

.

c. Aggregate Risk Mitigation

The Agency’s aggregate risk assessm ent for atrazine is based on exposure estim ates for drinking water based on m onitoring data and residential exposure estim ates based on chem icalspecific exposure data.

931) Acute Exposure

Acute aggregate exposure estim ates for atrazine are the sam e as those presented for acute drinking water risks because the Agency does not believe that high-end exposures through food, drinking water, and residential uses will all occur on the sam e day. Since acute drinking water risks do not exceed the Agency’s level of concern, acute aggregate risk is also acceptable, and no

m itigation m easures are necessary.

2) Intermediate-Term and Chronic Exposure

The aggregate risk assessm ent for interm ediate-term and chronic exposures to atrazine

and the chlorinated m e tabolites com b ines estim ates of high-end seasonal or long-term average exposures to atrazine in drinking water with long-term average exposures in food. Neither

interm ediate-term nor long-term exposures are expected to occur in or around the hom e from

residential uses of atrazine. Therefore, the interm ediate-term and chronic aggregate risk for

atrazine is the sam e as the interm ediate-term and chronic drinking water risk. As such,

m itigation m easures presented above to address interm ediate-term and chronic drinking water

risk also m itigates the interm ediate-term and chronic aggregate risk. No additional m itigation

m easures are needed to specifically address aggregate risk.

3) Short-Term Aggregate Exposure

The short-term (1-30 days) aggregate risk assessm ent com b ines short-term residential exposures with short-term drinking water exposures. If the short-term DW LOC is less than the

m easured average concentrations in surface water and groundwater, there is a risk of concern.

Short-term aggregate risk estim ates that include residential exposures to atrazine are only applicable for those regions of the United States where atrazine is used on turf, the Southeast (including Florida).

For adult handlers applying granular form ula tions of atrazine via bellygrinder, both residential exposures alone and aggregate exposures are of concern. To address the residential concern, the Agency has concluded that the app lication of granular lawn products using handheld devices should be lim ited to spot applications only.

For adults exposed to atrazine after it has been applied to turf or hom e lawns, neither residential exposure alone nor aggregate exposures are of concern. Therefore, no m itigation is

needed.

For children exposure to atrazine after it has been applied in liquid form ulations to hom e lawns, aggregate exposure is of concern. Com b in ed derm al and incidental oral exposures for toddlers result in a MOE of 180 for toddlers’ aggr egate derm al and oral exposures, based on the 1 lb ai/A rate necessary to address residential concerns alone. Since this is above the Agency’s level of concern, the short-term DW LOC is zero for aggregated exposures from liquid

form ulations across m u ltiple exposure routes for toddlers. However, since the lawn use of

atrazine is lim ited to the Southwest and Florida and the CW S of concern, with the exception of

94Iberville, LA, are in the Midwest, it is highly unlikely that hom e lawn exposure will occur at the

sam e tim e as high-end drinking water exposures.

For children exposed to atrazine after it has been applied as a granular form ulation to

hom e lawns, and watered-in, aggregate exposure is not of concern. Toddlers’ risk estim ates
from com b ined pathways for incidental oral e xposures based on granular form ulations result in an MOE of 730 and thus do not exceed the Agency’s level of concern. Toddlers’ risk estim ates
from derm al exposures based on granular form ulations also do not exceed HED’s levels of concern (MOE = 690 if not watered-in and 2000 if granules are watered-in im m e diately after application). For m o st CW S, short-term DW LOCs for toddlers’ post application aggregate exposures do not exceed the Agency’s level of concern for granular form ulations watered-in

af

ter application to turf

. Thus, m itigation m easures required f o r residential concerns alone (i.e, requiring that granular f o rm ulations be watered-in) m itigate any aggregate post-application

concerns. In addition, the few CW S that have 30-day average concentrations above the DW LOC are prim arily located in the Midwest (outside of atrazine turf use areas), with the exception of Iberville, Louisiana.

Further, all of the CW S with 30-day average concentrations above the DW LOC have also

been identified under the interm ediate-term drinking water risk assessm ent as of concern, including Iberville, Lousiana. As such, levels of atrazine in all of these CW S are being m itigated through the Agency’s localized atrazine drinking water m itigation plan described above.

d. Occupational Risk Mitigation

It is the Agency’s policy to m itigation occupational risks to the greatest extent necessary and feasible with personal protective equipm ent and engineering controls. In m a naging these risks, EPA m u st take into account the econom ic, social, and environm ental costs and benefits of the pesticide’s use. A wide range of factors is considered in m a king risk m a nagem e nt decisions

for worker risks. These factors include, in addition to the calculated MOEs, incident data, the nature and severity of adverse ef f

ect, uncertainties in the risk assessm ent, the cost, availability and relative risk of alternatives, im portance of the chem ical in integrated pest m a nagem e nt (IPM) program s, and other sim ilar factors.

Agricultural Handlers

Several occupational handler scenarios are not of concern at baseline levels of PPE (longsleeved shirt and long pants, shoes and socks); therefore, no risk m itigation is necessary at this

tim e in order for these uses to rem a in eligible for reregistration. These scenarios are described in

Section III.A.4. of this docum ent.

For the rem a ining agricultural handlers scenarios, occupational risks are of concern when considering the use of PPE or engineering controls (the m a xim u m f

easible m itigation). To

reduce m i xer/loader and applicator risk so that atrazine products are eligible for reregistration,

risk m itigation m easures are necessary. These m itigation m easures are explained in m o re detail

below.

951) Mixing/Loading Scenarios

Liquids:

• r equire closed system s for m i xing/loading to support aerial applications at greater than 3 lb ai/A

• a ll m i xers/loaders (including using engineering controls) m u st wear longsleeve shirt, long pants, shoes, socks, chem ical-resistant gloves and

chem ical resistant apron

W e ttable Powders:

• r equire water-soluble packaging for all W P form ulations

• a ll m i xers/loaders m u st wear long-sleeve shirt, long pants, shoes, socks,

chem ical-resistant gloves and chem ical resistant apron

Dry Flowables:

• w ater-soluble packaging optional

• i f in water-soluble packaging, all m i xers/loaders m u st wear long-sleeve shirt, long pants, shoes, socks, chem ical-resistant gloves and chem ical resistant apron

• i f not in water-soluble packaging, m i xers/loaders m u st wear coveralls over long-sleeve shirt and long pants, chem ical-resistant gloves, chem icalresistant footwear, and chem ical-resistant apron plus a NIOSH-approved

dust/m ist f iltering respirator with any N, R, P, or HE f ilter.

• i f not in water-soluble packaging, aerial application is prohibited.

Granular Products:

• L oaders m u st wear long-sleeve shirt, long pants, shoes, and socks.

2) Applicator and Flagger Scenarios

• P ilots m u st use enclosed cockpits (40 CFR 170.240(d)(6)) for aerial applications.

• H um an flaggers supporting aerial applications m u st used enclosed cabs (40 CFR 170.240(d)(5)).

• A pplicators applying sprays with m o torized ground equipm ent (i.e., groundboom or rights-of-way sprayers) m u st wear long-sleeve shirt, long pants, shoes, socks, and chem ical-resistant gloves.

• A pplicators applying granular products or im pregnated fertilizer m u st wear long-sleeve shirt, long pants, shoes, and socks.

In Addition:

• R estrict the im pregnation of bulk f e rtilizer to com m e rcial f a cilities (prohibit on-farm im pregnation)

• R estrict the im pregnation of dry bulk fertilizer to 500 tons per day for no

96m o re than 30 days per calender year per f acility

• R educe the m a xim u m application rate for handlers applying liquids with rights-of-way sprayers to 1.0 lb ai/A

• R educe the m a xim u m application rate for liquids for chem ical follow to

2.25 lb ai/A

• R equire a 60-day PHI for field corn forage uses

• R equire a 45-day PHI for sweet corn forage uses

• R equire a 60-day PHI for preem ergent uses and a 45-day PHI for

postem e rgent sorghum forage uses

3. Non-Agricultural Products including Law n s and Turf (not Sod Farms)

For turf and LCO uses of atrazine, handler risks are of concern, but can be m itigated through the use of PPE. To reduce this risk so that atrazine turf products are eligible for reregistration, risk m itigation m easures are necessary. These m itigation m e asures are explained

in m o re detail below.

• R equire that all wettable powder products be packaged in water soluble bags.

• G ranular form ulations: loaders, applicators, and other handlers m u st wear long-sleeve shirt, long pants, shoes, and socks.

• L iquid, wettable powder, dry flowable (water-dispersible granule)

form ulations:

- a pplicators using spray equipm ent m ounted on their backs m u st wear coveralls worn over long sleeved shirt and long pants,

chem ical-resistant gloves and chem ical-resistant footwear plus

socks.

- a ll other m i xers, loaders, applicators, and other handlers m u st wear long-sleeved shirt and long pants, shoes and socks, and chem ical resistant gloves.

• R educe the m a xim u m single application rate for liquid form ulations on

residential lawns and turf to 1 lb ai/A from 2 lb ai/A (liquid products containing >4% ai are restricted use)

• R equire that granular lawn products be watered in

Post-Application Occupational Risk

The Agency has not identified any post-application occupational risks from atrazine.

Theref ore, no m itigation m easures are needed at this tim e.

2. Environmental Risk Mitigation

The Agency has ecological risk concerns from the use of atrazine. The Agency has

97identified the potential for com m unity-level and population-level risk to aquatic ecosystem s at
concentrations of atrazine from 10 to 20 ppb.

To m itigate these ecological risks to aquatic com m unities, the Agency is requiring that atrazine registrants, in consultation with EP A, develop a program under which the registrants

m onitor for atrazine concentrations and m itigate environm ental exposures if EPA determ ines that

m itigation is necessary. The program will focus on watershed im pacts of atrazine use.

The program will include an appropriate ecological level of concern (LOC), including f o r endangered species, identified by EPA; developm ent of a protocol for a m onitoring program that specifies the frequency, location, and tim ing of sa m p ling, as well as an appropriate coordination with TMDL program s; triggers f o r m itigation m easures; and description of m itigation m e asures that will be taken if triggers are exceeded. This m onitoring and m itigation program would be designed, conducted and im plem ented on a tiered watershed level and m u st be consistent with existing state and f e deral water quality program s.

The requirem e nt that this process be established is presented in the Mem o randum of Agreem ent between the Agency and the atrazine technical registrants. Per the Mem o randum of Agreem ent, the Agency and the registrants m u st reach an agreem ent on the ecological

m onitoring program by April 30, 2003. If an agreem ent has not been reached, the Agency will identify any requirem e nts the Agency deem s necessary in the October 31, 2003, revision to the

Atrazine IRED. The establishm ent of a process to address ecological risks on a watershed basis allows the Agency to conclude that atrazine products are eligible for reregistration.

3. Other Labeling

Other use and safety inform ation need to be placed on the labeling of all end-use products containing atrazine, in addition to the m itigation m easures listed above and other existing label requirem e nts. For the specific labeling statem ents, refer to Section V of this

docum ent.

The Agency reserves the right to require additional label am endm ent to m itigate risks

f r om triazine residues. Any f u rther am endm ents will be discussed in the triazine cum u lative

decision.

a. Endangered Species Statement

The Agency has developed the Endangered Species Protection Program to identify pesticides whose use m a y cause adverse im pacts on endangered and threatened species, and to

im plem ent m itigation m easures that address these im pacts. The Endangered Species Act requires federal agencies to ensure that their actions are not likely to jeopardize listed species or adversely m odify designated critical habitat. To analyze the potential of registered pesticide uses to affect any particular species, EPA puts basic toxicity and exposure data developed for

98IREDs into context for individual listed species and their locations by evaluating im portant ecological param e ters, pesticide use inform ation, the geographic relationship between specific pesticide uses and species locations, and biologi cal requirem e nts and behavioral aspects of the particular species. This analysis will take into consideration any regulatory changes

recom m e nded in this IRED that are being im plem ented at this tim e. A determ ination that there is a likelihood of potential im pact to a listed species m a y result in lim itations on use of the pesticide, other m easures to m itigate any potential im pact, or consultations with the Fish and

W ildlife Service and/or the National Marine Fisheries Service as necessary.

The Endangered Species Protection Program as described in a Federal Register notice (54 FR 27984) is currently being im plem ented on an interim basis. As part of the interim

program , the Agency has developed County Speci fic Pam phlets that articulate m a ny of the specif i c m easures outlined in the Biological Opinions issued to date. The Pam phlets are available for voluntary use by pesticide applicators on EPA’s website at www.epa.gov/espp

. A final Endangered Species Protection Program , whic h m a y be altered from the interim program , is scheduled to be proposed for public com m e nt in the Federal Register before the end of 2001.

b. Spray Drift Management

The Agency is currently working with stakeholders to develop appropriate generic label

statem ents to address spray drift risk. Once this process has been com p leted, atrazine product labels will need to be revised to include this additional language.

99100V. What Registrants Need to Do

In order to be eligible for reregistration, registrants need to im plem ent the risk m itigation

m easures outlined in Section IV and V, which include, am ong other things, subm ission of the following:

For products containing atrazine , registrants need to subm it the following item s for each product within eight m onths of the date of the PDCI:

(1) an application for reregistration (EPA Form 8570-1, filled in, with a description on the application, such as, "Responding to Interim Reregistration Eligibility

Decision” docum ent); (2) f i ve copies of the draf t label incorporating all label am endm ents outlined in Table

17 of this docum ent; (3) responses to the generic and/or product specific Data Call-Ins (DCIs) as instructed in the enclosed DCIs; (4) two copies of the Confidentia l Statem ent of Form ula (CSF); and (5) a certification with respect to data com p ensation requirem e nts.

Note that the first set of required responses for the product-specific DCI is due 90 days

from the receipt of the DCI. The second set of required responses is due eight m onths from the

date of the DCI. For questions about product reregistration and/or the product-specific DCI, please contact Bonnie Adler at (703) 308-8523.

For the generic DCI , the following item s are due:

(1) DCI response form , due 90 days from the receipt of the DCI; (2) Registrant response form , due 90 days from the receipt of the DCI; and (3) the actual generic data in response to the DCI.

A. Manufacturing Use Products

1. Additional Generic Data Requirements

The generic data base supporting the reregistration of atrazine for the above eligible uses

has been reviewed and determ ined to be substantially com p lete. The following data gaps

rem a in:

Product Chem istry Data

Product-Specific Product Chem istry data requirem e nts have not been fulfilled (Series 830). Please see Product-Specific Data Call-Ins.

101Toxicology Data

Non-Guideline Study 28-day inhalation toxicity study m easuring LH surge and estrus cycle param e ters Non-Guideline Study Assessm ent of CNS alterations after atrazine exposure (recom m e nded)

Occupational Data

None

Environm ental Fate and Ecological Effects Data

OPPTS 850.2100 (71-1(a) ) Acute Avian Oral - Northern Quail (3 m a jor degradates) OPPTS 850.1075 (72-1(a) ) Acute Fish Toxicity Bluegill (m ajor degradate )

OPPTS 850.1075 (72-1(c) ) Acute Fish Toxicity Rainbow Trout (m ajor degradate) OPPTS 850.1010 (72-2(a) ) Acute Aquatic Invertebrate Toxicity (m ajor degradate) OPPTS 850.1025 (72-3(a) ) Acute Estuarine/Marine Fish Toxicity (m ajor degradate) OPPTS 850.1025 (72-3(b) ) Acute Estuarine/Marine Mollusk Toxicity (TGAI and

m a jor degradate) OPPTS 850.1025 (72-3(c) ) Acute Estuarine/Marine Shrim p Toxicity (m ajor degradate) OPPTS 850.1400 (72-4(a) ) Early Life-Stage Fish (Marine) (TGAI) OPPTS 850.1350 (72-4(b) ) Life-Cycle Marine Invertebrate (TGAI) OPPTS 835.4300 (162-4) Aerobic Aquatic Metabolism - Lab OPPTS 835.1410 (163-2) Volatility (Lab) OPPTS 850.1950 (165-5) Accum u lation in Aquatic Non-Target Organism s OPPTS 840.1100 (201-1) Spray Drift - Droplet Size Spectrum OPPTS 840.1200 (202-1 ) S pray Drif t - Drif t Field Evaluation OPPTS 830.7050 (NA) UV/Visible Absorption

Residue Chem istry Data

OPPTS 860.1380 (171-4e) Storage Stability OPPTS 860.1900 (165-2) Field Rotational Crop Study (in review) OPPTS 860.1500 (171-4k) Crop Field Trials - Crop Group 17 OPPTS 860.1360 (171-4) Multi-Residue Method

Other Data Requirem e nts

Non-Guideline Study Rural W e ll Monitoring Program (see MOA & DCI f o r details) Non-Guideline Study Surface W a ter CW S Monitoring Program (see MOA & DCI f o r details) Non-Guideline Study Ecological Monitoring and Mitigation Program (see MOA & DCI f o r details - specif i cs to be negotiated)

1022. Labeling for Manufacturing Use Products

To rem a in in com p liance with FIFRA, m a nufacturing use product (MUP) labeling should

be revised to com p ly with all current EPA regulations, PR Notices and applicable policies. The MP labeling should bear the labeling contained in Table 17 at the end of this section.

B. End-Use Products

1. Additional Product-Specific Data Requirements

Section 4(g)(2)(B) of FIFRA calls for the Agency to obtain any needed product-specific data regarding the pesticide af ter a determ ination of eligibility has been m a de. Registrants m u st review previous data subm issions to ensure that they m eet current EPA acceptance criteria and if

not, com m it to conduct new studies. If a registrant believes that previously subm itted data m eet current testing standards, then the study MRID num bers should be cited according to the instructions in the Requirem e nt Status a nd Registrants Response Form provided for each product.

A product-specific data call-in, outlining specific data requirem e nts, accom p anies this

interim RED.

2. Labeling for End-Use Products

Labeling changes are necessary to im plem ent the m itigation m easures outlined in Section

IV above. Specific language to incorporate these changes is specified in the Table 28 at the end

of this section.

C. Existing Stocks

Registrants m a y generally distribute and sell products bearing old labels/labeling for 26

m onths f r om the date of the issuance of this Interim Reregistration Eligibility Decision

docum ent. Persons other than the registrant m a y generally distribute or sell such products for 50

m onths from the date of the issuance of this interim RED. However, existing stocks tim e fram es will be established case-by-case, depending on the num ber of products involved, the num ber of label changes, and other factors. Refer to “Existing Stocks of Pesticide Products; Statem ent of Policy”; Federal Register , Volum e 56, No. 123, June 26, 1991.

The Agency has determ ined that registrants m a y not distribute or sell atrazine products bearing old labels/labeling after the date of cancellation or am endm ent unless it is for the purpose of relabeling in accordance with the term s of this interim RED. Persons other than the registrants m a y distribute or sell such products until October 1, 2003. Registrants and persons other than the registrants rem a in obligated to m eet pre-existing label requirem e nts and existing stocks requirem e nts applicable to products they sell or distribute. In addition, EPA has agreed to allow the atrazine technical registrants to re-l abel cancelled products with new provisions or to create supplem ental labeling that will allow distributors to provide new label language to

103purchasers of atrazine products with labels that do not com p ly with this interim RED.

D. Labeling Changes Summary Table

In order to be eligible for reregistration, am end all product labels to incorporate the risk

m itigation m easures outlined in Section IV. Table 29 below describes how language on the

labels should be am ended.

104Labeling Changes Summary TableIn order to be eligible for reregistration, amend all product labels to incorporate the risk mitigation measures outlined in Section IV.The following table describes how language on the labels should be amended.Table 29:Summary of Labeling Changes for AtrazineDescriptionAmended Labeling LanguagePlacement on LabelManufacturing Use ProductsOne of these statements maybeaddedtoa label toallowreformulation of the productfor a specific use or alladditionaluses supported bya formulator or user group“Onlyfor formulation into anherbicidefor the followinguse(s) [fill blankonly withthose uses that arebeing supported byMPregistrant].”Note:In addition tothe uses previouslyclassified asrestricted use, alluses of productscontaining >4%active ingredient must be classified as restricted use.Uses for totalvegetation controlon non-cropland areas (notincluding rights-of-ways, roadsides, or CRPprograms) are cancelled.Uses onpineapple, rangeland,andprosomillet are alsocancelled.Technicaland end-use productlabelsmustbe revised todeleteallreferences toand use-directions for thesecancelled use patterns.Directions for Use“This productmaybe used toformulate productsfor specific use(s) notlisted on the MPlabeliftheformulator, user group, or grower has complied withU.S. EPA submission requirements regardingsupportof such use(s).”“This product may be used to formulate products forany additional use(s) not listed on the MP label ifthe formulator, user group, or grower has complied withU.S. EPA submission requirements regardingsupportof such use(s).”Directions for UseTextrequired fromMemorandumof Agreement“This productmaynotbe reformulated or repackagedintoanother productunless the registration of thereformulated or repackaged productwas either granted or amended after March 15, 2004, so as tobeconsistentwiththe terms and conditions setforth inthe Atrazine January31, 2003 InterimReregistrationEligibility Document(IRED).”Directions for Use105DescriptionAmended Labeling LanguagePlacement on LabelTextrequired fromMemorandumof AgreementNo product(other than productscontaining 4% or less atrazine active ingredient) maybe formulated orrepackaged fromthisproductunless the formulated repackaged productbears a labelincluding allof thefollowing statements:The following language mustbe prominentlydisplayed inthe DIRECTIONS FORUSE on the label:“ANY USE OF THIS PRODUCT IN AN AREA WHERE USE IS PROHIBITED IS A VIOLATIONOF FEDERAL LAW.Before using thisproduct,youmustconsultthe Atrazine Watershed InformationCenter (AWIC)todetermine whether the use of thisproductisprohibited inyour watershed. AWICcanbe accessed throughwww.atrazine-watershed.info, or 1-866-365-3014.If use of this product isprohibited inyour watershed, you mayreturn thisproducttoyour pointof purchase or contact[insertnameof registrant]for a refund.”“No productcontaining 4% or less atrazine active ingredientmaybe formulated or repackaged fromthisproduct unless the registration ofthe resulting product includes the following terms and conditions: Theregistrant of this product shall immediately: i) cease all distributionand sale to any retailer or entitydistributing or selling such producttoanyretailer located withinallcounties containing anyportion ofthe Watershed Area listed inthe AWIC;ii)ensure the removalof such Atrazine productfromthe shelvesofany retailer locatedwithinall counties containingany portionofany WatershedArea listedintheAWIC; and iii) repurchase any such Atrazine product fromany of the purchasers described above.Inaddition,suchRegistrantshall consult withthe State(s) inwhichsuchcounties are locatedtodeterminewhether additional territory shall beincludedinthe area towhichthese requirements will apply.If theState(s) determine that a larger area is warranted, the Registrantshallwithin10 daysof suchdetermination notifythe Director of EPA’s SpecialReview and Reregistration Division (SRRD)(7508C), Office of Pesticide Programs, of the specific boundaries withinwhich the stop sale, removal,and repurchase shall take place.”Directions for UseEnvironmental Hazards“Do not discharge effluent containing this product into lakes, streams,ponds, estuaries, oceans, or otherwaters unless in accordance with the requirements ofa National Pollutant Discharge Elimination System(NPDES) permit andthe permittingauthority has beennotifiedinwritingprior todischarge.Donotdischarge effluentcontaining thisproducttosewersystems withoutpreviouslynotifying the localsewagetreatmentplantauthority.For guidance, contactyour State Water Board or RegionalOffice of the EPA.”Precautionary Statementsimmediately followingtheUser SafetyRecommendationsEnd Use ProductsIntended for OccupationalUse (WPS and NonWPS)106DescriptionAmended Labeling LanguagePlacement on LabelRestricted Use Pesticide(Inadditiontothe usespreviously restricted, all usesof productscontaining >4%active ingredientmustbeclassified restricted use)“RESTRICTED USE PESTICIDE”“Due to ground and surface water concerns.For retail sale to and use only by certified applicators orpersons under their directsupervision, and onlyfor those uses covered bythe certified applicator’scertification.”Top of frontpanelTextrequired fromMemorandumof Agreement“ANY USE OF THIS PRODUCT IN AN AREA WHERE USE IS PROHIBITED IS A VIOLATIONOF FEDERAL LAW.Before using thisproduct,youmustconsultthe Atrazine Watershed InformationCenter (AWIC)todetermine whether the use of thisproductisprohibited inyour watershed.AWICcanbe accessed through [www.atrazine-watershed.info], or [1-866-365-3014].If use of this product isprohibited inyour watershed, you mayreturn thisproducttoyour pointof purchase or contact[registrant]for a refund.”Directions for UsePPE RequirementsEstablished bythe IRED1for liquid productsthatdoNOT contain directions foruse on lawns or otherturfgrass“PersonalProtective Equipment(PPE)”“Some materials thatare chemical-resistanttothisproductare (registrant inserts correct chemicalresistant material).If you wantmore options, follow the instructions for category[registrantinsertsA,B,C,D,E,F,G,or H] “on an EPA chemical-resistance category selection chart.”“Mixers, loaders, applicators, flaggers, and other handlers mustwear:> Long sleeved shirtand long pants,> Chemical resistant gloves, such as (registrant insert correct chemical-resistantmaterials),> Shoes plus socks, and> Chemical-resistant apron,whenmixing/loading,cleaningupspills, orcleaningequipment, orotherwiseexposed tothe concentrate.”“See engineering controlsfor additionalrequirements.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic Animals107DescriptionAmended Labeling LanguagePlacement on LabelPPE RequirementsEstablished bythe IRED1for liquid productsthatDOcontain directions for use onlawns or other turfgrass“PersonalProtective Equipment(PPE)”“Some materials thatare chemical-resistanttothisproductare (registrant inserts correct chemicalresistant material).If you wantmore options, follow the instructions for category[registrantinsertsA,B,C,D,E,F,G,or H] “on an EPA chemical-resistance category selection chart.”“Applicators using sprayequipmentmounted on their backs mustwear:> Coverallsover long-sleeved shirtand long pants,> Chemical-resistant footwear plus socks, and> Chemical-resistant gloves, such as (registrant insert correct chemical-resistantmaterials).”“Mixers, loaders, allother applicators, flaggers, and other handlers mustwear:> Long sleeved shirtand long pants,> Chemical resistant gloves, such as (registrant insert correct chemical-resistantmaterials),> Shoes plus socks, and> Chemical-resistant apron,whenmixing/loading,cleaningupspills, cleaningequipment, orotherwiseexposed tothe concentrate.”“See engineering controlsfor additionalrequirements.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic Animals108DescriptionAmended Labeling LanguagePlacement on LabelPPERequirementsEstablished bythe IRED1for wettable powder and dryflowable (water dispersiblegranular) formulations inwater-soluble packets that doNOT contain directions foruse on lawns or otherturfgrass.Note: all wettablepowder productswithWPSuses on the labelmustbe inwater soluble packets to beeligible for reregistration.Dry flowable (waterdispersible granular)formulations are notrequired tobe inwatersoluble packets. Howeveraerialapplication isprohibited unless a dryflowable (water dispersiblegranular)formulation ispackagedinwater-solublepackets.“PersonalProtective Equipment(PPE)”“Some materials thatare chemical-resistanttothisproductare (registrant inserts correct chemicalresistant material).If you wantmore options, follow the instructions for category[registrantinsertsA,B,C,D,E,F,G,or H] “on an EPA chemical-resistance category selection chart.”“Mixers, loaders, applicators, flaggers, and other handlers mustwear:> Long sleeved shirtand long pants,> Chemical resistant gloves, such as (registrant insert correct chemical-resistantmaterials),> Shoes plus socks, and> Chemical-resistant apron,whenmixing/loading,cleaningupspills, cleaningequipment, orotherwiseexposed tothe concentrate.”“See engineering controlsfor additionalrequirements.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic Animals109DescriptionAmended Labeling LanguagePlacement on LabelPPERequirements“PersonalProtective Equipment(PPE)”ImmediatelyEstablished bythe IRED1following/belowfor wettable powder and dry“Some materials thatare chemical-resistanttothisproductare (registrantinserts correctchemical-Precautionary Statements:flowable (water dispersibleresistant material).If you wantmore options, follow the instructionsfor category[registrant insertsHazards to Humans andgranular) formulationsA,B,C,D,E,F,G,or H]“on an EPA chemical-resistance category selection chart.”Domestic Animalspackaged in water-solublepackets that DO contain“Applicators using sprayequipmentmounted on their backs mustwear:directions for use on lawns> Coverallsover long-sleeved shirtand long pants,or other turfgrass.Note: all> Chemical-resistant footwear plus socks, andwettable powder products> Chemical-resistant gloves, suchas (registrant insert correctchemical-resistant materials).”withWPS uses on the labelmust be in water soluble“Mixers, loaders, applicators, flaggers, and other handlers mustwear:packets to be eligible for> Long sleeved shirtand long pants,reregistration. Dry flowable> Chemical resistant gloves, suchas (registrant insert correctchemical-resistant materials),(water dispersible granular)> Shoes plus socks, andformulations are not> Chemical-resistant apron,whenmixing/loading,cleaningupspills, cleaningequipment, orotherwiserequired tobe inwater-exposed tothe concentrate.”soluble packets. Howeveraerialapplication is“See engineering controlsfor additionalrequirements.”prohibited unless a dryflowable (water dispersiblegranular)formulation ispackagedinwater-solublepackets.110DescriptionAmended Labeling LanguagePlacement on LabelPPERequirementsEstablished bythe IRED1for dryflowable (waterdispersible granule) productsNOT packaged in watersoluble packets that do NOTcontain directions for use onlawns or other turfgrass..Note: ifnotpackaged inwater-soluble packets, aerialapplication isprohibited.“PersonalProtective Equipment(PPE)”“Some materials thatare chemical-resistanttothisproductare (registrant inserts correct chemicalresistant material).If you wantmore options, follow the instructions for category[registrantinsertsA,B,C,D,E,F,G,or H] on an EPA chemical-resistance category selection chart.”“Mixers, loaders, cleaners of equipment or spills, and other handlers exposed to the concentrate mustwear:> Coverallsover long sleeved shirtand long pants,> Chemical-resistant gloves, such as (registrant insert correct chemical-resistantmaterials)> Chemical resistant footwear plus socks,> Chemical-resistant apron, and>A NIOSH-approveddust/mist filteringrespiratorwithany N, R, P orHE filter ora NIOSH-approveddust/mist filteringrespiratorwithapproval number prefixTC-21C).”Applicators and allother handlers exposed tothe dilutemustwear:> Long sleeved shirtand long pants,> Shoes plus socks, and> Chemical resistant gloves, such as (registrant insert correct chemical-resistantmaterials).”“Aerial applicationis prohibited.”“See engineering controlsfor additionalrequirements.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic Animals111DescriptionAmended Labeling LanguagePlacement on LabelPPERequirementsEstablished bythe IRED1for dryflowable (waterdispersable granule) productsNOT packaged in watersoluble packets that DOcontain directions for use onlawns or other turfgrass..Note: ifnotpackaged inwater-soluble packets, aerialapplication isprohibited.“PersonalProtective Equipment(PPE)”“Some materials thatare chemical-resistanttothisproductare” (registrant inserts correct chemicalresistant material).“If you wantmore options, follow the instructions for category”[registrantinsertsA,B,C,D,E,F,G,or H] “on an EPA chemical-resistance category selection chart.”“Mixers, loaders, cleaners of equipment or spills, and other handlers exposed to the concentrate mustwear:> Coverallsover long sleeved shirtand long pants,> Chemical-resistant gloves, such as (registrant insert correct chemical-resistantmaterials),> Chemical resistant footwear plus socks,> Chemical-resistant apron, and> A NIOSH-approveddust/mist filteringrespiratorwithany N, R, P orHE filter ora NIOSH-approveddust/mist filteringrespiratorwithapproval number prefixTC-21C).”“Applicators using sprayequipmentmounted on their backs mustwear:> Coverallsover long sleeved shirtand long pants,> Chemical-resistant gloves, such as (registrant insert correct chemical-resistantmaterials), and> Chemical resistant footwear plus socks.”“Allother applicators and allother handlers exposed tothe dilutemustwear:> Long sleeved shirtand long pants,> Shoes plus socks, and> Chemical resistant gloves, such as (registrant insert correct chemical-resistantmaterials).”“Aerial applicationis prohibited.”“See engineering controlsfor additionalrequirements.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic AnimalsPPE RequirementsEstablished bythe IRED1for granular products“PersonalProtective Equipment(PPE)”“Loaders, applicators and other handlers mustwear:> Long-sleeved shirtand long pants, and> Shoes plus socks.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic Animals112DescriptionAmended Labeling LanguagePlacement on LabelUser SafetyRequirements“Follow manufacturer'sinstructions for cleaning/maintaining PPE.If no such instructions for washablesexist,use detergentand hotwater.Keepand wash PPE separatelyfromother laundry.”If coveralls are specified in the handler PPE sectionof the label, use the following in addition to theabove statement:“Discard clothing and other absorbentmaterials thathave been drenched orheavily contaminated withthisproduct’s concentrate.Do notreuse them.”Precautionary Statements:Hazards to Humans andDomestic Animalsimmediately followingthePPE requirementsEngineering Controlsforliquid formulations thatcontain directions for usepermittingaerial application.“Engineering Controls”“Mixers and loaders supporting aerialapplicationsat a rate greater than 3 lbs ai/Amust use a closedsystemthatmeets the requirements for dermalprotection listed inthe Worker Protection Standard (WPS)for AgriculturalPesticides [40 CFR170.240(d)(4) and must:-wear the personalprotective equipment required for mixers and loaders,-wear protective eyewear ifthe systemoperates under pressure, and-be providedandhaveimmediately available for use inanemergency, suchas a spill orequipmentbreakdown:chemicalresistantfootwear.”“Pilots must use anenclosedcockpit ina manner that is consistentwiththe WPS for AgriculturalPesticides [40 CFR170.240(d)(6)]. Pilotsmustwear the PPE required on thislabeling for applicators,however, they need not wear chemical-resistantgloves when using an enclosed cockpit.”“Flaggers supporting aerial applications must use anenclosed cab that meets the definition on the WorkerProtection Standard for AgriculturalPesticides[ 40 CFR170.240 (d)(5)]for dermalprotection.”Precautionary Statements:Hazards to Humans andDomestic Animals(Immediately followingPPE and User SafetyRequirements.)Engineering Controlsforwettable powders and dryflowables (water dispersiblegranules) packaged in watersoluble packets.All wettablepowders withWPS uses mustbe in water soluble packetstobeeligible forreregistration.“Engineering Controls”“Water soluble packets when used correctlyqualifyas a closed mixing/loading systemunder the WorkerProtection Standard for AgriculturalPesticides [40CFR170.240(d)(4).Mixers and loaders using watersoluble packets must:-wear the personalprotective equipmentrequiredon thislabeling for mixers and loaders, and-be providedandhaveimmediately available for use inanemergency, suchas a brokenpackage, spill, orequipmentbreakdown, chemicalresistantfootwear.”Precautionary Statements:Hazards to Humans andDomestic Animals(Immediately followingPPE and User SafetyRequirements.)113DescriptionAmended Labeling LanguagePlacement on LabelEngineering Controlsforwettable powders and dryflowables (water dispersiblegranules) packaged in watersoluble packets that containdirectionsfor use permittingaerial application.Allwettable powders withWPSuses mustbe inwater solublepackets to be eligible forreregistration.“Pilots must use anenclosedcockpit ina manner that is consistentwiththe WPS for AgriculturalPesticides [40 CFR170.240(d)(6)]. Pilotsmustwear the PPE required on thislabeling for applicators,however, they need not wear chemical-resistantgloves when using an enclosed cockpit.”“Flaggers supporting aerial applications must use anenclosed cab that meets the definition on the WorkerProtection Standard for AgriculturalPesticides[ 40 CFR170.240 (d)(5)]for dermalprotection.Precautionary Statements:Hazards to Humans andDomestic Animals(Immediately followingthe water-solublepackaging engineeringcontrolrequirements.)AdditionalEngineeringControls Statement for allliquid, wettable powder, anddryflowableformulations.“When applicators use enclosed cabs in a mannerthat meets the requirements listedinthe WorkerProtection Standard (WPS) for agriculturalpesticides (40 CFR170.240(d)(5), the handler PPErequirements maybe reduced or modified as specified in the WPS.”Precautionary Statements:Hazards to Humans andDomestic Animals(Immediately followinganyother engineeringcontrolrequirements.)Engineering ControlsforGranular FormulationsNotetoregistrants:no engineering controlsstatementisneeded on labelsof granular formulations.notapplicableUser SafetyRecommendations“User SafetyRecommendations”“Users should wash hands beforeeating, drinking, chewing gum, using tobacco, or using the toilet.”“Users should remove clothing/PPE immediatelyifpesticide getsinside.Then wash thoroughlyand puton clean clothing.”“Users should remove PPE immediatelyafter handlingthisproduct.Wash the outside of gloves beforeremoving.As soon as possible, wash thoroughlyand change intoclean clothing.”Precautionary Statementsunder:Hazards toHumans and DomesticAnimals immediatelyfollowing EngineeringControls(Must be placed in a box.)114DescriptionAmended Labeling LanguagePlacement on LabelEnvironmental Hazards“Atrazine can travel (seep or leach) through soil and can enter ground water which may be used asdrinking water.Atrazine has been found inground water.Users are advised nottoapplyatrazine tosand and loamy sand soils where the water table (ground water) is close to the surface and where thesesoilsare verypermeable;i.e., well-drained.Yourlocal agricultural agencies can provide furtherinformation on the type of soilinyour area and the location of ground water.”Environmental Hazards“Product must not be mixed or loaded within 50 feet of intermittent streams and rivers, natural orimpounded lakes and reservoirs.Productmustnotbeapplied within66 feetof points where fieldsurface water runoff enters perennial or intermittent streams and rivers or within 200 feet of natural orimpounded lakes and reservoirs. If thisproductisapplied tohighlyerodible land, the 66 footbuffer orsetback fromrunoff entrypoints mustbe planted tocrop, or seeded withgrass or other suitable crop.”“Productmustnotbe mixed or loaded, or used within50 feetof allwells, including abandoned wells,drainage wells, and sink holes.Operations thatinvolve mixing, loading, rinsing, or washing of thisproductintoor frompesticide handling or applicationequipmentor containers within50 ft. of anywellare prohibited, unless conducted on an impervious pad constructed towithstand the weightof theheaviestload thatmaybe positioned on or moved across the pad.Such a pad shallbe designed andmaintained to contain any product spills or equipment leaks, containeror equipment rinse or wash water,and rain water that may fall on the pad.Surface water shall not be allowed to either flow over or formthe padwhichmeans the padmust beself-contained.The padshall beslopedtofacilitate materialremoval.An unroofed pad shallbe of sufficientcapacitytocontain ata minimum110% of the capacityof the largestpesticide container or application equipmenton the pad.A pad thatiscovered bya roof ofsufficient size to completely exclude precipitation fromcontactwiththe pad shallhave a minimumcontainmentof 100% of the capacityof the largestpesticide container or application equipmenton thepad.Containment capacities as described above shall be maintained at all times.The above-specifiedminimumcontainment capacities donotapply tovehicles whendeliveringpesticide tothemixing/loading sites.”“AdditionalState imposed requirements regarding well-head setbacks and operational area containmentmustbe observed.”115DescriptionAmended Labeling LanguagePlacement on LabelEnvironmental HazardsContinued“Oneofthe followingrestrictionsmust beusedinapplyingatrazinetotile-outlettedfieldscontainingstandpipes:-Do not apply within 66 feet ofstandpipes in tile-outletted fields.-Apply this product to the entiretile-outletted field and immediately incorporate it to a depth of2-3 inches in the entire field.-Apply this product to the entire tile-outletted field under a no-till practice only when a high cropresidue managementpractice ispracticed.Highcrop residue managementisdescribed as a cropmanagementpractice where little ornocropresidueis removedfromthe fieldduringandaftercrop harvest.”“This pesticide is toxic toaquatic invertebrates.Donotapply directly towater, toareas where surfacewater is present, ortointertidal areas below the mean high water mark.Do notapplywhen weatherconditions favor drift fromtreated areas.Runoffand drift fromtreated areas may be hazardous toaquaticorganisms inneighboring areas.Do notcontaminate water when disposing of equipmentwashwater.”Environmental HazardsRestricted-EntryInterval (forlabels withWPS uses)“Do not enter or allow worker entry into treated areas during the restricted entryinterval (REI) of 12hours.”Directions for Use,Agricultural UseRequirements BoxEarly Reentry PersonalProtective Equipmentestablished bythe IRED (forlabels withWPS uses.“PPE required for early entry to treated areas that is permitted under the Worker Protection Standard andthatinvolves contactwithanything thathas been treated, such as plants, soil,or water, is:> coveralls,> shoes plus socks, and> chemical resistant gloves, suchas any waterproof material.”116DescriptionAmended Labeling LanguagePlacement on LabelEntry RestrictionforEntry Restriction for non-WPSuses applied as a spray:If no WPS uses on theNonWPS useslabel, place the statements“Donotenter orallow others toenter until sprays havedried.”inthe Directionsfor UseUnder General Precautionsand Restrictions.Entry Restriction for non-WPS uses applied dry:If WPS uses are also on“Donotenter orallow others toenter until dusts havesettled.”the labeling, place thesestatements in aEntry Restriction for non-WPS uses applied as a solid(i.e. granular) and watered-in(for occupationalNonAgricultural Useuse to home lawns):Requirements box asspecified in PR Notice 93­“Donotenter orallow others toenter the treatedarea until dusts havesettled.If soil incorporationis7 and 93-11.required after the application, do notenter or allowothers to enter the treated area (except those personsinvolved in the incorporation) untilthe incorporation is complete. Ifthe incorporation is accomplished bywatering-in, do not enter or allow others to enter the treated area until thesurface is dry after thewatering-in.”117DescriptionAmended Labeling LanguagePlacement on LabelOther ApplicationRestrictions (RiskMitigation)All Products/Formulations Containing Atrazine“Do notapplythisproductthrough anytype of irrigation system”“When tank-mixing or sequentiallyapplying atrazine or productscontaining atrazine tocorn or sorghum,the total pounds of atrazine applied (lbs ai/A) must not exceed 2.5 pounds active ingredient per year.”“When tank-mixing or sequentiallyapplying atrazine orproductscontaining atrazine tocrops other thancorn or sorghum, the total pounds of atrazine applied(lbs ai/A) must not exceed the specific seasonal ratelimits as notedinthe use directions.”Delete all directionsfor use for the followinguse-patterns:>rangeland>totalvegetation controlon non-cropland areas (exceptConservation Reserve Program(CRP), rights-ofways, and roadsides)>prosomillet, andDirections for Use>pineapple uses.Products with Guava Uses:– “Do notapplymore than 4 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than 8 pounds active ingredientper year.”Macadamia Nut Uses:– “Do notapplymore than 4 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than 8 pounds active ingredientper year.”Conifers Uses:– “Do notapplymore than 4 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than 4 pounds active ingredientper year.”118DescriptionAmended Labeling LanguagePlacement on LabelOther ApplicationRestrictions (RiskMitigation)Sod Farm Uses-For muck or peatsoils:> “Do notapplymore than 4 pounds active ingredientper acre for anyapplication.”> “Do notapplymore than 6 pounds active ingredientper year.”-For sandy soils:>“Do notapplymore than 4 pounds active ingredientper acre for anyapplication.”> “Do notapplymore than 3 pounds active ingredientper year.”Conservation Reserve Program Uses:–“Do notapplymore than 2 pounds active ingredientper acre for anyapplication.”Chemical Fallow Uses:Directions for UseFor soilsinNorth and South Dakotawitha pH of7.5 or greater:–“Do notapplymore than 1.5 pounds active ingredientper acre for anyapplication.”–“Do notapplymore than one application per year.”For soilsinNorth and South Dakotawitha pH ofless than 7.5:–“Do notapplymore than 2.0 pounds active ingredientper acre for anyapplication.”–“Do notapplymore than one application per year.”For allother locations:–“Do notapplymore than 2.25 pounds active ingredientper acre for anyapplication.”–“Do notapplymore than one application per year.”119DescriptionAmended Labeling LanguagePlacement on LabelOther ApplicationRestrictions (RiskMitigation)continuedRights-of-Way Uses (applied as a spray):– “Do notapplymore than 1.0 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than one application per year.”Directions for UseSugarcane Uses:– “Do notapplymore than 4.0 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than 10.0 pounds active ingredientper acre per year.”Corn and Sorghum Uses:-Fieldcorn forage uses:60-dayPHI-Sweetcorn forage uses:45-dayPHI- Preemergentsorghumforage uses:60-dayPHI- Postemergentsorghumforage uses:45-dayPHI-“Postemergence applications to corn and sorghummust be made before crop reaches 12 inches inheight”“Maximumbroadcastapplication rates for corn and sorghummustbe as follows:> If no atrazine was applied prior tocorn/sorghumemergence, applya maximumof 2 lbai/Abroadcast.If a postemergence treatmentisrequired following an earlier herbicide application,the total atrazine applied may not exceed 2.5 lb ai/A per calendar year.> Applya maximumof 2.0 lbai/Aas a single preemergence application on soilsthatare nothighlyerodible or on highlyerodible soilsifatleast30% of the soiliscovered withplantresidues;or> Applya maximumof 1.6 lbai/Aas a single preemergence application on highlyerodible soilsif <30% of the surface is covered with plant residues; or 2.0 lb ai/A if only appliedpostemergence.”120DescriptionAmended Labeling LanguagePlacement on LabelOther ApplicationRestrictions (RiskMitigation)continuedRoadsides Uses:– “Do notapplymore than 1.0 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than one application per year.”DryBulk Fertilizer ImpregnationUses:- “Impregnationofbulkfertilizer is restrictedtocommercial facilities.On-farmfertilizer impregnationisprohibited.”- “No more than 500 tons of dry bulk fertilizer can be impregnated per day.”- “No single facility may impregnate fertilizer withthis product for more than to 30 days per calendaryear.”- “Thecommercial facility impregnatingthe dry bulkfertilizer must inform, inwriting,the user(applicator) ofthe dry bulkfertilizer that:> “Applicators mustwear long-sleeved shirt,long pants, shoes, and socks.”> “The restricted-entryintervalis12 hours.”Directions for UseApplication Restrictions forGranular formulations thatcontain directions for use onturfgrass at residential sites,including homes, daycarefacilities, schools,playgrounds, parks,recreational areas, and sportsfields“Turfgrass at Residential Sites(including homes daycare facilities, schools, playgrounds, parks,recreational areas, and sports fields:”“This productmustbe watered inimmediatelyafter application.Watering-inmustbe performed bythecommercial applicatororthe commercial applicatormust providethe followinginstructionstotheresidentor owner inwriting:>“This productmustbe watered inimmediately.>“Do notenter or allow others (including children or pets) toenter the treated areas (exceptthose involved in the watering) until the watering-in is complete and the surface is dry.”Directions for Use121DescriptionAmended Labeling LanguagePlacement on LabelApplication Restrictions forLiquid, Wettable Powder, orDry Flowable (WaterDispersible Granule)formulations thatcontaindirections for use onturfgrass at residential sites,including homes, daycarefacilities, schools,playgrounds, parks,recreational areas, and sportsfields“Turfgrass at Residential Sites(including homes daycare facilities, schools, playgrounds, parks,recreational areas, and sports fields):”– “Do notapplymore than 1.0 pounds active ingredientper acre for anyapplication.”– “Do notapplymore than 2.0 pounds active ingredientper acre per year.”Application Restrictions forDryFlowableFormulationsNOT packaged in watersoluble packets“Aerialapplication isprohibited.”Near the beginning of theDirections for Use inboldtype and red lettering.End Use ProductsIntended Primarilyfor Use byHomeownersEnvironmental Hazards“Atrazine can travel (seep or leach) through soil and can enter ground water which may be used asdrinking water.Atrazine has been found inground water.Users are advised nottoapplyAtrazine onsand and loamy soils where the water table (ground water) is close to the surface and where these soilsare verypermeable;i.e., welldrained.Your localagricultural agencies can provide further informationon the type of soilinyour area and the location of ground water.Thisproductistoxic toaquaticinvertebrates.Do not apply directlyto water, to areas where surface water is present or to intertidal areasbelow the mean high water mark.Runoff and drift fromtreated areas may be hazardous to aquaticorganisms inneighboring areas.Do notcontaminate water when disposing of equipmentwashwaters.”Precautionary Statements122DescriptionAmended Labeling LanguagePlacement on LabelApplication RestrictionsAll products:“Do not apply this product in a way that will contact any person or pet, either directly or through drift.Keep people and petsoutof the area during application.”Granular Products Applied Dry:“This productmustbe watered inimmediatelyafter application.”Directions for Use underGeneral Precautions andRestrictionsStatements must be in thecolor redandinall caps.Entry RestrictionProducts Applied as a Liquid:“Donotallow people orpets toenter the treatedarea until sprays havedried.”Products Applied Dry:“Do notenter or allow others (including children or pets) toenter the treated areas (exceptthose involvedin the watering) until the watering-inis complete and the surface is dry.”Directions for Use underGeneral Precautions andRestrictionsStatements must be in thecolor redandinall caps.123DescriptionAmended Labeling LanguagePlacement on LabelPrecautionary StatementsFor Granular Lawn Products:“Do notapplygranular lawn productsbyhand. Avoid contactwithhands or skin.”“Broadcastapplications mustNOT be made using hand-helddevices, such as a bellygrinder or handheldrotaryapplicator. Such equipmentmayonlybe used for spottreatments.”Immediatelyfollowing/belowPrecautionary Statements:Hazards to Humans andDomestic AnimalsFor Liquid products:- “Maximumrateper application turfgrass (including lawns) is [registrantinsert the maximumrate oftheformulated productper unitarea – such as 2 pints per 1,000 square feet– thatreflects an maximumapplication rateof 1 pound active ingredientper acre].”– “Maximumof two applications per year.”124

# APPENDICES

125126Appendix A:ATRAZINE USE PATTERNS ELIGIBLE FOR REREGISTRATIONSiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsFOOD/FEED USE PATTERNSCornBroadcast or bandedEarlyPreplant; preplant surface orincorporated, preemergence, orpostemergence to corn#12" tallGround or aerial applications90% DF4 lb/gal FlCOthersd1.6preemergence onhighlyerodiblesoil if < 30%surface coveredwith plantresidues2 preemergenceon not highlyerodible soil or if> 30% surfacecovered withplant residues2 postemergenceNS(Notspecified)2.560 forforage60 forfield corn45 forsweetcornNSFor preplant surface treatments,use onmedium or fine-texturedsoils with reducedtillage systems onlyin CO, IA, IL, IN, KS,KY,MN, MO, MT, ND,NE, SD, WIandWY, up to 45 dayspreplanting; on coarsetextured soils, do not apply>2 weeks prior toplanting.BroadcastFallow weed control (and continuedcontrol in following minimumtillage corn).Applied to stubbleground after wheat harvest in awheat-corn-fallow crop rotation.Ground or aerial applications90% DF4 lb/gal FlC31.5(ND & SD soilswith pH>7.5)2.0(ND & SD soilswith pH<7.5)1NSNSNSUselimited to CO, KS, ND,NE, SD, andWY. Wheat-corn-fallow cropping sequencemust be followed.Do not applyfollowing corn harvest. An 18­month plant-back restriction is specified forall crops other than those on the label.Grazing or feeding of forage from treatedareasare prohibited.127SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsBroadcastWinter weed control in TXGround or aerial applications90% DF4 lb/gal FlC0.8-1.0NSNSNSN/AFor postemergence control of winter weedsonlyon fall bedded land in the Gulf Coastand Blacklandsof TX.Normal weedcontrol programs maybe used in thefollowing corn, grain sorghum, or sorghumforage crops the following spring.The labelprohibits planting anycrops except corn,grain sorghum, or forage sorghum in thespring following this treatment.GuavaBroadcastGround application90% DF4 lb/gal FlC4.038.0NS120Use onlyon established guava at least 18months old. Label states, "do not applymorefrequntlythan at 4-month intervals".“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 8 pounds activeingredient per year.”Grain Sorghum orSorghum-sudan hybrids (grain and foragetypes)128SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsBroadcast or bandedEarlyPreplant; preplant surface orincorporated, preemergence, orpostemergence to sorghum#12" tallGround or aerial applications90% DF4 lb/gal FlCOthersd1.6preemergence onhighlyerodiblesoil if < 30%surface coveredwith plantresidues2 preemergenceon not highlyerodible soil or if> 30% surfacecovered withplant residues2 postemergenceNS2.560 forforage60 forpreemerg.use45 forpostemer.useNSA 60-dayPGI or PHI for forage is in effect.For preplant surface treatments,use onmedium or fine-texturedsoils with reducedtillage systems onlyin CO, IA, IL, IN, KS,KY,MN, MO, MT, ND,NE, SD, WIandWY, up to 45 dayspreplanting; on coarsetextured soils, do not apply>2 weeks prior toplanting.Do not applypreplant surface orincorporated in AL, AR, FL, GA,LA, MS,NC, NM, OK,SC, TN, or TX.Donot applypreemergence in NM, OK, or TX, except innortheast OK, the TX Gulf Coast andBlacklandsareas.BroadcastWinter weed control in TXGround or aerial applications90% DF4 lb/gal FlC0.8-1.0NSNSNSNAFor postemergence control of winter weedsonlyon fall bedded land in the Gulf Coastand Blacklandsof TX.Normal weedcontrol programs maybe used in thefollowing corn, grain sorghum, or sorghumforage crops the following spring.The labelprohibits planting anycrops except corn,grain sorghum, or forage sorghum in thespring following this treatment.BroadcastFallow weed control (and continuedcontrol in minimumtillage sorghum)applied to stubble ground followingwheat harvest in a wheat-sorghumfallow crop rotation.Ground or aerial applications90% DF4 lb/gal FlC31NSNSNAWheat-sorghum-fallow cropping sequencemust be followed.Do not applyfollowing sorghum harvest. An18-month plant-back restriction is specifiedfor all crops other than those on the label.Grazing or feeding of forage from treatedareasare prohibited.Macadamia nuts129SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsBroadcastGround application90% DF4 lb/gal FlC4.0NS8.0NSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplications.”“Do not applymore than 8 pounds activeingredient per year.”Soybeans(Unspecified)43% EC2.5NSNSNSNSSugarcaneBroadcast or bandedPreemergence (at-planting orratooning) followed byoneapplication at emergence, and up totwo interline post-emergencedirected applicationsprior to closein (lay-by).Ground or aerial application90% DF4 lb/gal FlC2-4410NSNSTreatments maybe made applied in aminimum of 20 gal/A of water bygroundand 5 gal/A of water byair.A reasonableinterval between lay-byand harvest wouldbe 120-150 days, providing a built-in PHI.In FL and TX, 0.5-1 gal of surfactant/100 galof spraymaybe used.In LA, an applicationof 2 lb ai/A maybe used to control annualweeds during summer fallow period; afterplanting applicationsmaynot exceed 8 lbai/A.FallowWheat Stubble(Wheat is not a targetcrop)BroadcastFallow weed control applied tostubble ground following wheatharvest in a wheat-fallow-wheatcrop rotation.Ground or aerial applications90% DF4 lb/gal FlC0.5-11NSNSNAUse limited to CO,KS,ND,NE,SD,andWY.Grazing of treated areas is prohibited for 6months, and a 12-month plant-back intervalfor wheat isspecified.NON FOOD/NON FEED USE PATTERNSAgricultural Fallow/Idleland130SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsAt Planting43% EC43% SC/L90% DF2.2512.25NSNS“Do not applymore than 2.25 pounds activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”Established Plantings90% DF11NSNSNSFall43% EC90% DF1NSNSNSNSFallow20.9% EC21.92% FlC43% EC43% FlC43% SC/L80% WP85.5% DF90% DF90% WP2.2512.25NSNS“Do not applymore than 2.25 pounds activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”FebruaryMarch90% DF1NSNSNSNSLate Fall43% FlC0.410.4NSNS85.5% DF90% DFPostharvest22% FlC111NSNS43% EC90% WPPreemergence43% EC2NSNSNSNSPreplant43% SC/L85.5% DF90% DF131SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsRenovation43% EC2NS2NSNSSpring85.5% DF90% DFStubble22% EC22% FlC43% EC43% SC/L53.5% EC80% WP90% DF90% WP2.2512.25NSNS“Do not applymore than 2.25 pounds activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”BermudagrassDormant, spring43% EC90% DF2NSNSNSNSChristmasTree PlantationsFall,EarlySpring21.42 EC80% WP4NSNSNSNSCommercial/industrial LawnsEarlySpring.58% G.92% G0.046 lb 1Kft2NSNSNSNSFall.45% G0.046 lb 1Kft2NSNSNSNS.92% G1.05% GPost-plant25% FIC.75NSNSNSNSSpring132SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations.45% G.92% G1.05% G0.046 lb 1Kft2NSNSNSNSConifers(SeedOrchard)Dormant43% EC90% WP4NS4NSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplications.”“Do not applymore than 4 pounds activeingredient per year.”Forest Plantings(ReforestationPrograms)(Tree Farms,Tree Plantations,Etc.)EarlySpring80% WP41NSNSNSFall80% WP90% WP41NSNSNSForest Trees(Softwoods,Conifers)Dormant43% EC43% FIC85.5% DF90% DF414NSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”EarlySpring25% FIC90%DF90% WP3.961NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Established Planting133SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% EC43.6% EC53.48% EC80% WP85.5% DF90% DF41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Fall25% FIC43% EC90% DF90% WP41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Post-Plant43% DF43% EC4.41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Post-transplant43% EC43% SC/L43.5% EC43.6% EC53.48% EC80% WP85.5% DF90% DF90% WP41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Pre-plant (Spring)134SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% DF43% EC4.41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Pre-transplant43% RC43% SC/L43.5% EC43.6% EC53.48% EC80% WP85.5% DF90% DF90% WP41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Spring43% DF43% EC4.41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Transplant43% EC43% SC/L43.5% EC85.5% DF90% DF41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Winter135SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% DF43% EC4.41NSNSNS“Do not applymore than 4 pounds activeingredient per acre for anyapplication.”“Do not applymore than 4 pounds activeingredient per year.”Golf Course TurfAt Planting90% DF099NSNSNSNSDormant53.48% EC90% DF2.5NSNSNSNSEarlySpring90% DF1.98NSNSNSNSFall.45% G.6% G.92% G43% EC43% FIC53.48% EC89% WP90% DF90% WP2NSNSNSNSFoliar53.48% EC90% DF2.5NSNSNSNSLate Winter136SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations.6% G43% EC43% FIC53.48% EC80% WP90% DF90.1% DF2NSNSNSNSPost-plant25% FIC.75NSNSNSNSSpring.45%G.6% G.92% G.046 lb/1Kft2NSNSNSNSWinter90% DF1.982NSNSNSGrasses Grown forSeedDormant43% FIC90% DF1NSNSNSNSNonagricultural Rightsof way/fencerows/hedgerowsDelayed Dormant43% EC11NSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”Dormant137SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% EC53.48 EC2.5NSNSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”EarlySpring90% DF90.1% FIC3.961NSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”Fall43% EC43% FIC43% SC/L43.5% EC43.6% EC53.48% EC80% WP85.5% DF90% DF90% WP90.1% DF90.1% FIC2.41NSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”Foliar43% EC53.48% EC2.5NSNSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”Spring138SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% EC43% FIC43% SC/L43.5% EC43.6% EC53.48% EC80% WP85.5% DF90% DF90% WP90.1% DF90.1% FIC41NSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”When Needed43% EC2NSNSNSNS“Do not applymore than 1 pound activeingredient per acre for anyapplication.”“Do not applymore than one application peryear.”Ornamental And/or ShadeTreesDormant43% EC90% DF41NSNSNSEarlySpring53.48% EC90.1% DF41NSNSNSEstablished Planting90% DF3.961NSNSNSFall53.48% EC90.1% DF41NSNSNS139SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsPost-transplant43% EC53.48% EC90% DF90.1% DF41NSNSNSPre-transplant43% EC53.48% EC90% DF90.1% DF41NSNSNSTransplant43% EC90.1% DF41NSNSNSOrnamental Lawns and TurfDormant23.6% FIC43% EC43% FIC43% SC/L53.48% EC90% DF41NSNSNS“This product must be watered inimmediatelyafter application.”EarlySpring.58% G.92% G43% FIC90% DF1.98NSNSNSNS“This product must be watered inimmediatelyafter application.”EarlyWinter.92% G.046 lb/1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”Fall140SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations042% G.57% G.6% G.63% G.79% G.83% G.91% G.92% G1.05% G1.11% G1.15% G1.16% G1.28% G1.41% G1.5% G43%EC43% FIC80% WP85.5% DF90% DF90% WP2NSNSNSNS“This product must be watered inimmediatelyafter application.”Foliar1.1% G23.6% FIC43% EC43% FI43%SC/L53.48% EC80% WP90% DF2.5NSNSNSNS“This product must be watered inimmediatelyafter application.”Late Winter141SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations.6% G.8% G1.11% G43% EC43% FIC43% SC/L43.5% EC43.6% EC80% WP90% DF90.1% DF4NSNSNSNS“This product must be watered inimmediatelyafter application.”Postplant.42% G.44% G.91% G.75NSNSNSNS“This product must be watered inimmediatelyafter application.”Preemergence90% DF1.982NSNSNS“This product must be watered inimmediatelyafter application.”Spring142SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations.42% G.57% G.6% G.63% G.79% G.83% G.91% G.92% G1.05% G1.11% G1.15% G1.16% G1.28% G1.5% G.048lb/1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”Summer.6% G1.05% G.046lb/1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”When Needed08% G.83% G.92% G1.22% G1.41% G43% EC2NSNSNSNS“This product must be watered inimmediatelyafter application.”Winter.42% G.63% G.91% G1.05% G90% DF1.98NSNSNSNS“This product must be watered inimmediatelyafter application.”Ornamental Sod Farm(Turf)143SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsAt Planting90% DF3.96NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Dormant53.48% EC90% DF2NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”EarlySpring90% DF2NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Fall144SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations.45% G.92% G43% EC43% FIC53.48% EC85.5% DF90% DF90% WP2NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Foliar43% EC43% FIC53.48% EC85.5% DF90% DF90% WP43% EC4NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Late Winter43% EC43% FIC53.48% EC85.5% DF90% DF90% WP90.1% DF43% EC2NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Post Harvest145SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% EC43% FIC53.48% EC85.5% DF90% DF90% WP90.1% DF4NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Post Plant43% EC43% FIC53.48% EC85.5% DF90% DF90% WP90.1% DF4NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Post-transplant80% WP4NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Preemergence, Pretransplantand Preplant146SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% DC/L4NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”Spring.455G.92% G.046 lb 1Kft2NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”When Needed43% EC90% DF3.96NSNSNSNS“For muck or peat soils: do not applymorethan 4 pounds active ingredient per acre foranyapplication.”“Do not applymore than 6 pounds activeingredient per year.”“For sandy soils: do not applymore than 4pounds active ingredient per acre for anyapplication.”“Do not applymore than 3 pounds activeingredient per year.”RangelandEstablished Planting147SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations43% EC90% DF11NSNSNSMarch90% DF11NSNSNSPreemergence43% EC11NSNSNSRecreationArea LawnsDormant43% EC43% FIC43% SC/L53.48% EC90% DF2.5NSNSNSNSEarlySpring43% FIC90% DF1.98NSNSNSNSFall1.05% G0.046 lb 1Kft2NSNSNSNSFoliar43% Ec43% FIC43% SC/L53.48% EC90% Df2.5NSNSNSNSLate Winter80% Wp90% DF22NSNSNSPost-plant25% FIC.75NSNSNSNS148SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use LimitationsSpring1.05% G0.046 lb 1Kft2NSNSNSNSRecreational AreasFall.45% G.92% G0.046 lb 1Kft2NSNSNSNSSpring.45% G.92% G0.046 lb 1Kft2NSNSNSNSResidential LawnsDormant14% EC23.6% FIC43% EC43% FIC53.48% EC90% DF2.5NSNSNSNS“This product must be watered inimmediatelyafter application.”EarlySpring14% EC43% FIC90% DF1.98NSNSNSNS“This product must be watered inimmediatelyafter application.”EarlySummer14% Ec0.046 lb 1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”Fall149SiteApplication TypeApplication TimingApplication EquipmentFormulationMax. SingleApplication Rate(lb ai/A)Max. #Apps/seasonMax AnnualApplicationRate (lb ai/A)PreharvestInterval(days)MinimumRetreatmentInterval(days)Use Limitations.45% G.6% G.92% G1.05% G14% EC0.046 lb 1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”Foliar23.6% FIC43% EC43% FIC53.48% EC90% DF2.5NSNSNSNS“This product must be watered inimmediatelyafter application.”Late Winter.6% G14% EC80% WP90% DF2NSNSNSNS“This product must be watered inimmediatelyafter application.”Mid-Winter14% EC0.046 lb 1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”Post-Plant25% FIC.75NSNSNSNS“This product must be watered inimmediatelyafter application.”Spring.45% G0.6% G.92% G1.05% G14% EC0.046 lb 1Kft2NSNSNSNS“This productmust be watered inimmediatelyafter application.”150151Appendix B: STUDIES USED TO SUPPO RT THE REREGISTRATION OF ATRAZ INE

GUIDE TO APPENDIX B

Appendix B contains listing of data require m e nts which support the reregistration for active ingredients within the case atrazine covered by this IRED. It contains generic data requirem e nts that apply to atrazine in all products, including data requirem e nts for which a "typical form ulation" is the test substance.

The data table is organized in the following form ats:

1. Data Requirem e nt (Colum n 1). The data requirem e nts are listed by Guideline Num b er. The Guideline Num b ers accom p anying each test refer to the test protocols set in the

Pesticide Assessm ent Guidance available f r om the National Technical Inf o rm ation Service, 5285 Port Royal Road, Springfield, VA 22161 (703) 487-4650.

2. Use Pattern (Colum n 2). This colum n indicates the use patterns for which the data requirem e nts apply. The following letter designations are used for the given use patterns.

A . Terrestrial Food H. Greenhouse Food

B. Terrestrial Feed I. Greenhouse Non-Food

C. Terrestrial Non-Food J. Forestry

D. Aquatic Food K. Residential

E. Aquatic Non-Food Outdoor L. Indoor Food

F. Aquatic Non-Food Industrial M. Indoor Non-Food

G. Aquatic Non-Food Residential N. Indoor Medical

O. Indoor Residential

3. Bibliographic Citation (Colum n 3). If the Agency has acceptable data in its files, this

colum n list the identify num ber of each study. This norm a lly is the Master Record Identification (MRID) num ber, but m a y be a "GS" num ber if no MRID num ber has been assigned. Refer to the Bibliography appendix for a com p lete citation of the study.

152APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID NumberPRODUCT CHEMISTRY830.155061-1Product Identity and CompositionAll40566501, 43188901, 43505801830.1600830.1620830.165061-2AStarting Materials and Manufacturing ProcessAll40566501830.167061-2BFormation of ImpuritiesAll00142160, 42043501, 43188901830.170062-1PreliminaryAnalysisAll00142160, 00164821, 42043501,42211401, 42873701, 42925201,44488801830.175062-2Certification of LimitsAll40566501, 42925201, 43188901830.180062-3AnalyticalMethodAll00142160, 00164821, 42873701830.630263-2ColorAll00142160830.630363-3PhysicalStateAll00142160830.630463-4OdorAll00142160830.7050NoneUV/Visible AbsorptionAlldata gap830.720063-5Melting PointAll00142160, 00164822830.722063-6Boiling PointAllnot applicable830.730063-7DensityAll00023548, 43016501, 43188902153APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number830.7840830.786063-8SolubilityAll00023497, 43337901830.795063-9Vapor PressureAll00142160, 00164822830.737063-10Dissociation ConstantinWaterAll00022855830.7550830.7560830.757063-11Partition Coefficient (Octanol/Water)All00142160, 00164822, 43337901830.700063-12pHAll00142160, 43337901830.631363-13StabilityAll00023497, 00023548, 00023963,43337901, 43796001830.631463-14Oxidizing/Reducing ActionAll43016501, 43188902830.631563-15FlammabilityAllnot applicable830.631663-16ExplodabilityAll43016501, 43188902830.631763-17Storage StabilityAll0023548, 43395501830.710063-18ViscosityAllnotapplicable830.631963-19MiscibilityAllnot applicable830.632063-20Corrosion CharacteristicsAll00142160, 43016501, 43188902ECOLOGICAL EFFECTS850.210071-1Avian Acute OralToxicityTestABCJK00024721 (parent)data gap (3 major degradates)154APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number850.220071-2Avian DietaryToxicityABCJK00022923850.230071-4Avian ReproductionABCJK42547102, 42547101850.107572-1 (a & b)Fish Acute Toxicity- FreshwaterABCJK00024717, 00024716 (parent)data gap (major degradate)850.101072-2AcuteAquaticInvertebrateToxicityABCJK00024377 (parent)data gap (major degradate)850.107572-3aAcute Estuarine/Marine Toxicity- FishABCJK43344901 (parent),data gap (major degradate)850.102572-3bAcute Estuarine/Marine Toxicity- Invertebrate(Mollusk)ABCJKdata gap (parent and majordegradate)72-3cEstuarine/Marine Toxicity- Invertebrate(Shrimp)ABCJK43344902 (parent)data gap (major degradate)850.140072-4aEarlyLife-Stage Fish (Freshwater)ABCJK4520830472-4aEarlyLife-Stage Fish (Marine)ABCJKdata gap45202920 (upgradable)850.130072-4bLife-CycleAquaticInvertebrateABCJK00024377850.135072-4bLife-CycleMarine InvertebrateABCJK45202920, data gap850.150072-5Life-Cycle FishABCJK00024377850.4225850.4230123-1aSeedling Germination/Seedling EmergenceABCJK42041403155APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number850.42501231bVegetative VigorABCJK42041402850.4400123-2AquaticPlantGrowthABCJK41065203a & b43074801, 43074802, 43074803850.3020141-1NontargetInsectAcute ContactToxicity(HoneyBee)ABCJK00036935TOXICOLOGY- Parent Atrazine870.110081-1AcuteOral- RatAll00024706, 00027097Accession No. 230303870.120081-2AcuteDermal- RabbitAll00024708, 00027097Accession Nos. 230303;231466870.130081-3AcuteInhalation - RatAll42089901, 43016502870.240081-4Primary Eye Irritation - RabbitAllAccession No. 23030300024709870.250081-5Primary Dermal Irritation - RabbitAllAccession No. 23030300024709, 00024710870.260081-6Dermal SensitizationAll00105131870.310082-190-DayFeedingAll44723701870.320082-221-DayDermalToxicity- RatAll42089902870.370083-3DevelopmentalToxicityAll41065201, 00143008, 40566302Accession No. 25497900143006, 40566301870.380083-4Reproduction andFertility Effects - 2 Generation ReproAll40431303, 42743903156APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number870.4100870.430083-1A83-5Chronic Feeding Toxicity- RodentCombined Chronic Toxicity/CarcinogenicityAll40629302, 42227001, 43934402,00158930, 43532001870.410083-1BChronic Feeding Toxicity- Non-Rodent(dog)All40431301870.420083-2AOncogenicity- RatAll40629302, 42227001, 42204401,43934402, 00158930870.420083-2BOncogenicity- MouseAll40431302non-guidelinenon-guidelineSpecialStudies - NeurotoxicityAll44152102, 43934406, 45166902,45166901870.510084-2BacterialReverse Mutation AssayAll00060642, 40246601870.538584-2Micronucleus AssayAll40722301870.545084-2RodentDominantLethalAssayAll42637003870.555084-2UDS AssayAll00161790, 40722301, 42547105870.748585-1GeneralMetabolismAll40431304, 40431305, 40431306,42165503, 44713802, 40437501870.760085-2DermalAbsorptionAll43314302 (rat)44152114 (human)non-guidelinenon-guidelineSpecialStudies - Assaysof DirectEstrogenic ActivityofTriazinesAll43598617, 43598618, 43598619,43934403non-guidelinenon-guidelineSpecialStudy- Estrous Cycle Alterations and LH SurgeAttenuation - Method ValidationAll43934405non-guidelinenon-guidelineSpecialStudy- Estrous Cycle Alterations and LH SurgeAttenuation- PilotAll43934404157APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Numbernon-guidelinenon-guidelineSpecialStudy- Estrous Cycle Alterations and LH SurgeAttenuation - 28-dayAll43934406non-guidelinenon-guidelineSpecialStudy- Estrous Cycle Alterations and LH SurgeAttenuation - 6-monthAll44152102non-guidelinenon-guidelineSpecialStudy- Hormone and Estrous Cycle MeasurementsinSD RatsAll42085001, 42743902, 43598622non-guidelinenon-guidelineSpecialStudy- MammaryGland and OvarianHistomorphologyinSD RatsAll43598622, 42085001, 42743902non-guidelinenon-guidelineSpecialStudy- Two-Year BioassayinF-344 RatsAll42146101, 42743902, 43598622non-guidelinenon-guidelineSpecialStudy- Hormone and Estrous Cycle MeasurementsinF-344 RatsAll42743902, 42146101, 43598622non-guidelinenon-guidelineSpecialStudy- MammaryGland and OvarianHistomorphologyinF-344 RatsAll43598622, 42146101, 42743902,44917701non-guidelinenon-guidelineSpecialStudy- Two-year Bioassaywiththe SD Strainof RateAll42204401non-guidelinenon-guidelineSpecialStudy- Tumor Incidence inOvariectomized (OVX) vsIntact AnimalsAll44544701non-guidelinenon-guidelineSpecialStudy- SexualMaturationAll45058702, 45722401non-guidelinenon-guidelineLong-TermEstrous Cycle MeasurementsAllUnaudited draftreportof the interimestrous cycle datafrom44544701non-guidelinenon-guidelineDirectComparison of LH Surge Attenuation of Atrazine,Simazine, and DactAll45471002, 45058701158APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Numbernon-guidelinenon-guidelineOther published literatureAllCooper et al. 1996Shafer etal. 1999Das etal. 2000Cummings etal. 2000Narotskyetal. 2000Laws etal. 2000Stoker etal. 2000TOXICOLOGY- Degradate DACT870.110081-1AcuteOral- RatAll43013201870.310082-1ASubchronic OralToxicityinRatsAll43013207870.3150870.410082-1B83-1BSubchronic & Chronic OralToxicityinDogsAll41392401870.370083-3DevelopmentalToxicityinRatsAll41392402870.510084-2MutagenicityStudy- BacterialReverse MutationAll40722302870.555084-2MutagenicityStudy- UDS AssayAll40722303TOXICOLOGY- Degradate DesisopropylAtrazine870.110081-1AcuteOral- RatAll43013201870.310082-1ASubchronic OralToxicityinRatsAll43013205870.315082-1BSubchronic OralToxicityinDogsAll43013203870.370083-3DevelopmentalToxicityinRatsAll43013208870.510084-2MutagenicityStudy- BacterialReverse Mutation AssayAll43093101159APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number870.538584-2MutagenicityStudy- Mammalian Bone Marrow ChromosomeAberration TestAll43093103870.555084-2MutagenicityStudy- UDS AssayAll43093105TOXICOLOGY- Degradate Deethyl Atrazine870.110081-1AcuteTox - RatAll43013202870.310082-1ASubchronic OralToxicityinRatsAll43013206870.315082-1BSubchronic OralToxicityinDogsAll43013203870.370083-3DevelopmentalToxicityinRatsAll43013209870.510084-2MutagenicityStudy- BacterialReverse Mutation AssayAll43093102870.538584-2MutagenicityStudy- Mammalian Bone Marrow ChromosomeAberration TestAll43093104870.555084-2MutagenicityStudy- UDS AssayAll43093106TOXICOLOGY- Degradate Hydroxyatrazine870.310082-1ASubchronic OralToxicityinRatsAll41293501870.370083-3DevelopmentalToxicityinRatsAll41065202870.4100870.430083-1A83-5Chronic Toxicity- RatAll43532001870.510084-2MutagenicityStudy- BacterialReverse Mutation AssayAll40722304870.538584-2MutagenicityStudy- Mammalian Bone Marrow ChromosomeAberration TestAll41479401160APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number870.555084-2Other GeneticEffectsAll40722305, 40888101EPIDEMIOLOGYnon-guidelinenon-guidelineCancer EpidemiologicStudies - Submitted to EPAAll45152101, 45518401, 44008601non-guidelinenon-guidelineCancer Epidemiologic Studies - Other Published LiteratureAllAlvanja etal. 2003Breckenridge 2002Breckenridge 2003MacLennan etal. 2002MacLennan etal. 2003Mills 1998OCCUPATIONAL/RESIDENTIAL EXPOSURE875.1100875.1300875.1500231232235Applicator Exposure Monitoring (Dermaloutdoor exposure,Inhalation outdoor exposure, Biologicalmonitoring)ABCJK43934416, 43934417, 43934418,44152109, 44152110, 44152111,44315403, 44315404, 43598604875.1500235BiologicalMonitoringABCJK4459760544597606875.1100231DermalExposureABCJK43016506875.1100875.1300231232Exposure Monitoring (ORETF)ABCJK44972201875.2100132-1Foliar DislodgeableResidue DissipationABCJ44883601875.2100132-1Transferable Residue Dissipation:Lawn and TurfCK44958001, 44958801, 45517301840.1100201-1202-1Droplet Size SpectrumDrift FieldEvaluationABCJKdata gap161APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Numbernon-guidelinenon-guidelineDermalTransfer Efficiencyof Granular Atrazine ResiduesFromTurf toDryand Wetted PalmsCK45622310, 45622311non-guidelinenon-guidelineExposure AssessmentsABCJK44152106, 44152108, 45399905,44597604ENVIRONMENTAL FATE835.2120161-1Hydrolysis of Parentand DegradatesABCJK40431319835.2240161-2Photodegradation - WaterABCJK42089904, 45545301835.2410161-3Photodegradation - SoilABCJK4043132042089905835.2370161-4Photodegradation - AirABCJKnotapplicable835.4100162-1Aerobic SoilMetabolismABCJK42089906835.4200162-2Anaerobic SoilMetabolismABCJK42089906835.4400162-3Anaerobic AquaticMetabolismABCJK40431323835.4300162-4Aerobic AquaticMetabolismABCJKdata gap835.1240163-1Leaching/Adsorption/DesorptionABCJK40431324,40431325, 40431326,40431327, 40431328835-1410163-2Volatility-LabABCJKdata gap835.6100164-1TerrestrialField DissipationABCJK42165504, 42165505, 40431336,42165506, 40431337, 42165507835.1200164-2Aquatic(sediment)DissipationABCJKnotapplicable835.1300164-3ForestryDissipationABCJK40431340, 42041405162APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number835.1500164-5Soil,Long TermDissipationABCJK40431339, 42089911, 40431337,42089912, 40431338, 42089909,40431336, 42089910850.1730165-4Bioaccumulation in FishABCJK40431344850.1950165-5Bioaccumulation in Non-Target OrganismsABCJKdata gapENVIRONMENTAL FATE - DRINKING WATER MONITORING DATAnon-guidelinenon-guidelineAtrazine Drinking Water Monitoring Data(PLEX & VMP)All43598634, 43934413, 43934414,44152122, 44152123, 44152124,44315414, 44597601, 44711001,44856901, 44997001, 44997003,45058703, 45058704, 45145601,45209601, 45253401, 45475101,45475102, 45545305, 45622305non-guidelinenon-guidelineAtrazine Drinking Water Monitoring Data(ARP)All45728401, 45730200, 45722700Acetochlor Registration Partnership(ARP) Final Report for the StateMonitoring Programnon-guidelinenon-guidelineAtrazine RuralWellMonitoring DataALLdata gapnon-guidelinenon-guidelineAtrazine Ground-Water Monitoring DataAll43934414, 44222601, 44222602,45399906, 45545304,data gapRESIDUE CHEMISTRY163APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number860.1300171-4ANature of Residue - PlantsAB0002332400023529 0002247400024786 00055672001494280016185400016306412098014254711642547115430165034304850143598628435986294415211944152120441521214431540844315409860.1300171-4BNature of Residue - LivestockAB0002285700038297001618540001630600038294404313524043135340431354404313554043135640431357404375024120980241209803412098044120980641209807412098084292560143508501 43934412860.1340171-4CResidue AnalyticalMethod - PlantsAB00016401000164020001640300023499000235020002448000024482000556440009352040431365413971024254711842547119430165044431541243395502860.1340171-4DResidue AnalyticalMethod - AnimalsAB00023280000235020016185440431364404313694043137040431422404314244139710342547120425471214254712242547123860.1360Multiresidue MethodsAB41423401,data gap164APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number860.1380171-4EStorage StabilityAB0002448240431421404314264125860141258602412586034139710143395503,data gap860.1480171-4JMagnitude of Residues - Meat, Milk, Poultry,EggsMilk and the Fat, Meat, and Meat Byproducts of Cattle,Goats, Hogs, Horses, and SheepEggs and the Fat,Meat, and MeatByproductsof PoultryAB00026977, 00080629, 00093524,4043142440431422, 40431423860.1500171-4KCrop Field Trials - Macadamia NutsAB00024799, 40431418860.1500171-4KCrop Field Trials- Corn, field and sweet, K+CWHRAB00094135, 00093523, 40431401,42547117, 43598630, 44152117,44315410, 44597602, 45399901860.1500171-4KCrop Field Trials- SorghumgrainAB00093523, 40431383, 43598631,43598632, 44152118, 44315411,44597603, 45399902860.1500171-4KCrop Field Trials- WheatgrainAB00024475, 40431420, 43160502860.1500171-4KCrop Field Trials- Corn forage and stoverAB0009352000093523000941354043140143598630441521174431541044597602860.1500171-4KCrop Field Trials- Sorghumforage and stoverAB000935234043138343598631435986324431541144597603860.1500171-4KCrop Field Trials- Wheatforage, fodder, straw, grasses, andforageAB00024475000674254043142043160502data gap165APPENDIX B.Data Supporting Guideline Requirements for the Reregistration of AtrazineDATA REQUIREMENTCITATION(S)New GuidelineNumberOldGuidelineNumberStudy TitleUse PatternMRID Number860.1500171-4KCrop Field Trials- Orchardgrass, orchardgrass hay,rye,perennialAB00024487860.1500171-4KCrop Field Trials- RangeGrassesAB00126712data gap860.1500171-4KCrop Field Trials- GuavaAB00055643860.1500171-4KCrop Field Trials-SugarcaneAB00115588, 43160504860.1520171-4LProcessed Foods (Corn)AB43160505860.1520171-4LProcessed Foods (Sorghum)AB43160503860.1520171-4LProcessed Foods (Sugarcane)AB43160504, 43395504860.1520171-4LProcessed Foods (Wheat)AB43160502860.1850165-1Confined RotationalCropAB43016505860.1900165-2FieldRotationalCropAB43160501PROBABILISTIC ASSESSMENTSnon-guidelinenon-guidelineProbabilistic Drinking Water Exposure AssessmentAll45503101, 45503102, 45622306,45629401, 45711308non-guidelinenon-guidelineProbabilistic Ecological Risk AssessmentAll45299501, 45299505, 45622302,45622303166167Appendix C: TECHNICAL SUPPORT DOCUMENTS

Additional docum entation in support of this IRED is m a intained in the OPP docket,

located in Room 119, Crystal Mall #2, 1921 Jeffers on Davis Highway, Arlington, VA. It is open Monday through Friday, excluding legal holidays, from 8:30 am to 4 pm

.

The docket initially contained the February 14, 2001 prelim inary hum an health risk

assessm ent, and the Septem ber 26, 2001 prelim inary ecological fate and effects risk assessm ent
and related docum ents. EPA then considered com m e nts on these risk assessm ents, revised the

risk assessm ents, and added the form al “Response to Com m e nts” docum ents and the revised risk

assessm ents to the docket in May 2002. Additional response to com m e nts docum ents and

docum ents supporting the IRED were published in January 2003.

All docum ents, in hard copy form , m a y be viewed in the OPP docket room or downloaded or viewed via the Internet at the following sites:

www.epa.gov/pesticides/op http://cascade.epa.gov/RightSite/dk_public_hom e.htm

These docum ents include:

SRRD Documents:

• A trazine Mem o randum of Understanding. January 31, 2003

• A trazine Sum m a ry. May 2, 2002

• A trazine Overview. May 2, 2002

HED Documents:

IRED Supporting Docum e nts

• A trazine: Addendum to Revised Hum a n Health Risk Assessm ent for the Reregistration Eligibility Decision (RED) dated April 16, 2002. January 31, 2003

• A trazine: Reassessm ent of DW LOC value for use in hum an health risk assessm ent. January 31, 2003

• A trazine: Addendum to Revised Occupational and Residential Exposure Assessm ent and

Recom m e ndations f o r the Reregistration Eligibility Decision Docum e nt. January 31,

2003

• A trazine: Response to Public Com m e nts on the EPA’s April 16, 2002, Revised Hum a n Health Risk Assessm ent and Associated Docum e nts f o r the Reregistration Eligibility Decision (RED). January 31, 2003

• R eview of Additional Data on Potential Atrazine Exposure and Review Com m e nts
Subm itted by Syngenta and NRDC on Atrazine Cancer Epidem iology Study: “Follow-up Study of Cancer Incidence Am ong W o rkers in Triazine-related Operations at the Novartis St. Gabriel Plant” by Elizabeth Delzell et al. January 15, 2003.

168• A trazine: Response to Syngenta’s Com m e nts on the EPA’s April 16, 2002, Revised

Hum a n Health Risk Assessm ent and Associated Docum e nts for the Reregistration Eligibility Decision (RED). Novem b er 22, 2002

Revised Risk Assessm ents and Supporting Docum e nts

• A trazine: HED’s Revised Hum a n Health Risk Assessm ent for the Reregistration Eligibility Decision (RED). April 16, 2002

• A trazine: Response to Public Com m e nts on the EPA’s January 19, 2001, Revised

Prelim inary Hum a n Health Risk Assessm ent and Associated Docum e nts for the Reregistration Eligibility Decision (RED). April 16, 2002

• A trazine: Response to Syngenta’s Com m e nts on the EPA’s January 19, 2001, Revised

Prelim inary Hum a n Health Risk Assessm ent and Associated Docum e nts for the Reregistration Eligibility Decision (RED). April 16, 2002

• A trazine/DACT - Reassessm ent Report of the FQPA Saf e ty Factor Com m ittee. April 8,

2002

• A trazine/DACT - Fourth Report of the Hazard Identification Assessm ent Review

Com m ittee. April 5, 2002

• A trazine: Metabolism Assessm ent Review Com m ittee. Residues to be Regulated and Residues of Concern for Dietary Assessm ent. Novem b er 15, 2000

• A trazine: Toxicology Chapter of the Reregistration Eligibility Decision. Second

Revision. April 11, 2002

• A trazine: HED Product and Residue Chem istry Chapters. April 16, 2002

• A trazine: Revised Occupational and Residential Exposure Assessm ent and

Recom m e ndations for the Reregistration Eligibility Decision Docum e nt. April 25, 2002

• R esponse to Com m e nts from Sipcam Agro. April 18, 2002

• A trazine: Review of Probabilistic Exposure Assessm ent for Drinking W a ter from 28

Com m unity W a ter System s. April 23, 2002.

• A ddendum and Corrections to Occupational and Residential Exposure Chapter for

Atrazine. May 23, 2002.

• R eview of Atrazine Cancer Epidem iology Studies: “A Follow-up Study of Mortality

Am ong W o rkers at the Novartis St. Gabriel Plant” “Follow-up Study of Cancer Incidence

Am ong W o rkers in Triazine-related Operations at the Novartis St. Gabriel Plant” both by

Elizabeth Delzell et al. March 25, 2002.

• R eview of Atrazine Cancer Epidem iology Study “Follow-up Study of Cancer Incidence

Am ong W o rkers in Triazine-related Operations at the Novartis St. Gabriel Plant” by

Elizabeth Delzell et al. Decem ber 13, 2001.

Prelim inary Risk Assessm ents and Supporting Docum e nts

• E PA’s Response to Syngenta’s Com m e nts on the Prelim inary Hum a n Health Risk

Assessm ent for Atrazine in Support of the Reregistration, Tolerance Reassessm ent, and Special Review. January 23, 2001

• A trazine - Drinking W a ter Exposure Assessm ent for Atrazine and Various ChloroTriazine and Hydroxy-Triazine Degradates. J anuary 23, 2001

169• A trazine - Toxicology Chapter of the Reregistration Eligibility Decision - Revised. January 19, 2001

• A trazine - HED’s Revised Prelim inary Hum a n Health Risk Assessm ent f o r the Reregistration Eligibility Decision (RED). January 19, 2001

• A trazine - Anticipated Residues and Acute and Chronic Dietary Exposure Assessm ents for Atrazine, Revised January 2001. January 18, 2001

• A trazine - HED Product and Residue Chem istry Chapters. January 18, 2001

• A trazine - Occupational and Residential Exposure Assessm ent and Recom m e ndations for the Reregistration Eligibility Decision Docum e nt. January 18, 2001

• A trazine - 3 rd Report of the Hazard Identification Assessm ent Review Com m ittee.

Decem ber 21, 2000

• A trazine - Evaluation of Carcinogenic Potential. Decem ber 13, 2000

• A trazine - Reevaluation by the FQPA Safety Factor Com m ittee. Novem b er 14, 2000

• A trazine - Cancer Peer Review Com m ittee Meetings - Provisional Conclusions.

Novem b er 1, 2000

• R eview of Atrazine Incident Reports. October 31, 2000

• D iam i nochlorotriazine (DACT) - Report of the Hazard Identification Assessm ent Review

Com m ittee. August 28, 2000

• H ydroxyatrazine - Report of the Hazard Iden tification Assessm ent Review Com m ittee. August 28, 2000

EFED Documents:

IRED Supporting Docum e nts

• E PA Response to Com m e nts from Syngenta a nd its Contractors, the Triazine Network, the Center for Regulatory Effectiveness, the Am erican W a ter W o rks Association, the State of New York Office of Attorney General, the U.S. Departm e nt of Interior Fish and

W ildlif e Service, the Calif ornia Regional W a ter Control Board, the Am erican Farm Bureau Federation, and the Louisiana Farm Bureau Federation, about the EPA Reregistration Eligibility Science Chapter f o r Atrazine, Environm ental Fate and Ef f

e cts Chapter, dated April 22, 2002. March 2003 (Replaces January 2003 Response to Comments document)

• R eregistration Eligibility Science Chapter f o r Atrazine: Environm ental Fate and Ef f

ects Chapter (and Appendices). January 31, 2003

• E PA Response to Com m e nts. January 28, 2003

Revised Risk Assessm ents and Supporting Docum e nts

• R eregistration Eligibility Science Chapter f o r Atrazine. Environm ental Fate and Ef f

e cts Chapter (and appendices). April 22, 2002.

• E FED Review of Com m e nts from Syngenta a nd Its Contractors About the EPA Revised

Environm ental Risk Assessm ent for Atrazine. April 22, 2002

• E FED Review of Public Com m e nts in Reponse to the EPA Revised Environm ental Risk

170Assessm ent for Atrazine. April 10, 2002

• R esponse to Com m e nts Contained in Attachm e nt 6 of Syngenta’s Com m e nts on
“Atrazine. HED’s Revised Hum a n Health Risk Assessm ent for the Reregistration Eligibility Docum e nt.” April 9, 2002

Prelim inary Risk Assessm ents and Supporting Docum e nts

• R esponse to Syngenta’s Error Corrections of EPA’s Atrazine RED and Environm ental Fate and Effects Chapter (including Appendices). March 16, 2001

171Appendix D: CITATIONS CONSIDERED TO BE PART OF THE DATA BASE

SUPPORTING THE INTERIM REREGISTRATION DECISION (BIBLIOGRAPHY)

GUIDE TO APPENDIX D

1. CONTENTS OF BIBLIOGRAPHY. This bib liography contains citations of all studies considered relevant by EPA in arriving at th e positions and conclusions stated elsewhere in the Reregistration Eligibility Docum e nt. Prim ary sources f o r studies in this bibliography have been the body of data subm itted to EPA and its predecessor agencies in support of past regulatory decisions. Se lections from other sources including the published literature, in those instances where they have been considered, are included.

2. UNITS OF ENTRY. The unit of entry in this bibliography is called a "study." In the case of published m a terials, this corresponds closely to an article. In the case of unpublished m a terials subm itted to the Agency, the Agency has sought to identify

docum ents at a level parallel to the published article f r om within the typically larger

volum es in which they were subm itted. The resulting "studies" generally have a distinct title (or at least a single subject), can stand alone f o r purposes of review and can be described with a conventional bibliographic citation. The Agency has also attem p ted to

unite basic docum ents and com m e ntaries upon them , treating them as a single study.

3. IDENTIFICATION OF ENTRIES. The entries in this bibliography are sorted

num erically by Master Record Identifier, or "MRID” num ber. This num ber is unique to the citation, and should be used whenever a specific reference is required. It is not related to the six-digit "Accession Num b er" which has been used to identify volum es of

subm itted studies (see paragraph 4(d)(4) below f o r f u rther explanation). In a f e w cases, entries added to the bibliography late in the review m a y be preceded by a nine character

tem porary identif ier. These entries are listed af ter all MRID entries. This tem porary identifying num ber is also to be used whenever specific reference is needed.

4. FORM OF ENTRY. In addition to the Master Record Identifier (MRID), each entry consists of a citation containing standard elem ents followed, in the case of m a terial

subm itted to EPA, by a description of the earliest known subm ission. Bibliographic

conventions used reflect the standard of the Am erican National Standards Institute (ANSI), expanded to provide for certain special needs.

a A uthor. W h enever the author could confidently be identified, the Agency has chosen to show a personal author. W h en no individual was identified, the Agency

has shown an identif iable laboratory or testing f acility as the author. W h en no author or laboratory could be identif ied, the Agency has shown the f i rst subm itter

as the author.

172b. Docum e nt date. The date of the study is taken directly from the docum ent. W h en the date is followed by a question m a rk, the bibliographer has deduced the date

from the evidence contained in the docum ent. W h en the date appears as (1999), the Agency was unable to determ ine or estim ate the date of the docum ent.

c. Title. In som e cases, it has been necessary for the Agency bibliographers to

create or enhance a docum ent title. Any such editorial insertions are contained between square brackets.

d. Trailing parentheses. For studies subm itted to the Agency in the past, the trailing parentheses include (in addition to any self-explanatory text) the following

elem ents describing the earliest known subm ission:

(1) S ubm ission date. The date of the earliest known subm ission appears

im m e diately following the word "received."

(2) A dm inistrative num ber. The next elem ent im m e diately following the word "under" is the registration num ber, experim e ntal use perm it num ber, petition num ber, or other adm i nistrative num ber associated with the

earliest known subm ission.

(3) S ubm itter. The third elem ent is the subm itter. W h en authorship is

def a ulted to the subm itter, this elem ent is om itted.

(4) V olum e Identification (Accession Num b ers). The final elem ent in the trailing parentheses identifies the EPA accession num ber of the volum e in which the original subm ission of the study appears. The six-digit

accession num ber follows the sym bol "CDL," which stands for "Com pany Data Library." This accession num ber is in turn followed by an alphabetic suffix which shows the relative position of the study within the volum e.

173BIBLIOGRAPHY

MRID Citation

00002875 Frear, D. E. H. and J. E. Boyd. 1967. Use of Daphnia magna for t h e

m i crobioassay of pesticides. I. Developm ent of standardized techniques for rearing Daphnia and preparation of dosage-m o rtality curves f o r pesticides. J.

Econ. Entom o l. 60(5):1228-1236.

00016306 Herm es, P. (1972) Biphasic Extraction of Radioactive Metabolites from Treated Biological Material. Method no. AG-214 dated Aug 15, 1972. (Unpublished study received Sep 26, 1974 under 5F1606; subm itted by Ciba-Geigy Corp., Greensboro, N.C.; CDL: 094385-Q)

00016401 Cannizzaro, R.D.; Li, C. (1972) Determ in ation of Atrazine Residues in Dry Crops by Gas Chrom a tography. Method no. AG-145 dated Nov 29, 1972. (Unpublished study received Feb 18, 1977 under 100-583; subm itted by Ciba-Geigy Corp., Greensboro, N.C.; CDL: 228126-L)

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40431301 O' Connor, D.; McCorm ick, G.; Green, J. (1987) Chronic Toxicity Study in Dogs: Atrazine Technical: Laboratory Study No. 852008. Unpublished study prepared by Ciba-Geigy Corp. 1405 p.

40431302 Hazelette, J.; Green, J. (1987) Oncogeni city Study in Mice: Atrazine Technical: Laboratory Study No. 842120. Unpublished study prepared by Ciba-Geigy Corp. 3160 p.

40431303 Mainiero, J.; Youreneff, M.; Giknis, M.; et al. (1987) Two-generation Reproduction Study in Rats: Atrazine Technical: Laboratory Study No. 852063. Unpublished study prepared by Ciba-Geigy Corp. 1395 p.

40431304 Orr, G. (1987) Disposition of Atrazine in Rat: (General Metabolism ) : Atrazine: Laboratory Study No.: ABR-87048. Unpub lished study prepared by Ciba-Geigy Corp. 62 p

40431305 Thede, B. (1987) Study of Carbon 14 F -Atrazine Dose/Response Relationship in the Rat: (General Metabolism ) : Laboratory Study No. ABR-87087. Unpublished

183study prepared by Ciba-Geigy Corp. 53p.

40431306 Miles, B. (1987) Characterization and Id entification of Atrazine Metabolites from Rat Urine: (General Metabolism ) : Laboratory Study No.: ABR-87115. Unpublished study prepared by Ciba-Geigy Corp. 35 p.

40431319 Spare, W

. 1986. Determ ination of the hydrolysis rate constants of atrazine: Laboratory Study. No. 1236. 33 p. Unpublished study prepared by Agrisearch Inc., Frederick, MD; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431320 Spare, W

. 1987. Photodegradation of atrazine on soil surfaces exposed to artificial and natural sunlight: Laboratory Study No.1237. 68 p. Unpublished study prepared by Agrisearch Inc., Frederick, MD; Subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431321 Rustum , A. 1987. Aerobic, aerobic/anaerobic, and sterile soil m e tabolism of carbon 14-atrazine: Laboratory Study No. 6015-185. 133 p. Unpublished study prepared by Hazleton Laboratories Am erica, Inc., Madison, W I ; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431322 Klaine, S. 1987. Biotic and abiotic degradation of atrazine and three of its

m e tabolites in a west Tennessee soil: Laboratory Study No. TX-431. 63 p. Unpublished study prepared by Mem phis State University, Mem phis, TN;

subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431323 Spare, W

. 1987. Anaerobic aquatic m e tabolism of atrazine: Laboratory Study No. 1231. 69 p. Unpublished study prepared by Agrisearch, Inc., Frederick, MD;

subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431324 Yu, W

. C. 1986. Determ ination of adsorption/desorption constants of atrazine: Laboratory Study No. 59-1A. 33 p. Unpublished study prepared by Cam b ridge Analytical Associates, Inc., Boston, MA; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431325 Yu, W

. C. 1986. Determ ination of adsorption/desorption constants of G-28279: Laboratory Study No. 59-6A. Unpublished study prepared by Cam b ridge Analytical Associates, Inc., Boston, MA; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431326 Yu, W

. C. 1986. Determ ination of adsorption/desorption constants of G-34048: Laboratory Study No. 59-7A. Unpublished study pr epared by Cam b ridge Analytical Associates, Inc., Boston, MA; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431327 Yu, W

. C. 1986. Determ ination of adsorption/desorption constants of G-28273:

184Laboratory Study No. 59-5A. Unpublished study prepared by Cam b ridge Analytical Associates, Inc., Boston, MA; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431328 Yu, W

. C. 1986. Determ ination of adsorption/desorption constants of G-30033: Laboratory Study No. 59-6A. Unpublis hed study prepared by Cam b ridge Analytical Associates, Inc., Boston, MA; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431330 Saxena, A. M. 1987. Determ ination of the m obility of soil-aged 14 C-atrazine residues by thin-layer chrom a togr aphy: Laboratory Study No. HLA 6015-186. Unpublished study prepared by Hazleton, Laboratories Am erica, Inc., Madison,

W I ; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431336 W h ite, S. 1987. Field dissipation study on Aa trex Nine-O for terrestrial uses on bareground, Ripon, California: Labor atory Study No. 1641-86-71-01-21E-23. 300 p. Unpublished study prepared by Minnesota Valley Testing Labs, Inc., New

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, MN; Subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431337 W h ite, S. 1987. Field dissipation study on Aa trex Nine-O for terrestrial uses on bareground, Hollandale, Minnesota: Laboratory Study No. 1641-86-71-01-21E-25. 356 p. Unpublished study prepared by Minnesota Valley Testing Labs, Inc., New Elm

, MN; subm itted by Ciba-Geigy Corp., Greensboro,

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40431338 W h ite, S. 1987. Field dissipation study on Aa trex Nine-O for terrestrial uses on corn, Ripon, California: Laborat ory Study No.1641-86-71-01-06B-22. 311 p. Unpublished study prepared by Minnesota Valley Testing Labs, Inc., New Elm

, MN; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40431339 W h ite, S. 1987. Field dissipation study on Aa trex Nine-O for terrestrial uses on corn, Hollandale, Minnesota: Labor atory Study No. 1641-86-71-01-06B-24. 372

p. Unpublished study prepared by Minnesota Valley Testing Labs, Inc., New Elm

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40431340 Schofield, M. 1986. Com b ined field di ssipation and aquatic non-target organism

accum u lation Studies on Aatrex Nine-O for forestry use at Oregon City, Oregon: Laboratory Study No. 32989. 135 p. Unpublished study prepared by Analytical

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40431344 Forbis, A. 1986. Uptake, depuration, and bioconcentration and m e tabolite characterization of carbon 14-atrazine by bluegill sunfish ( Lepomis

macrochirus ): Laboratory Study No. 34737. 107 p. Unpublished study prepared by Analytical Bi o-Chem istry Laboratories, Inc.; subm itted by Ciba-Geigy Corp.,

185Greensboro, NC .

40431352 Caballa, S. (1973) The in vitro Metabolism of Carbon 14 -Atrazine and Derivatives by Rat and Sheep Liver under Tissue Culture Conditions: (Nature of

Residue--Metabolism ) : Laboratory Study No.: GAAC-73035. Unpublished study prepared by Ciba-Geigy Corp. 30p.

40431353 Sim oneaux, B. (1987) Distribution and Characterization of Carbon 14 -Atrazine in a Goat: (Nature of Residue--Metabolism ) : Laboratory Study No.: ABR-86056. Unpublished study prepared by Ciba-Geigy Corp. 42 p.

40431354 Thede, B. (1987) Study of Solubilized Re sidues from Protease Treated Tissues of Carbon 14 -Atrazine Dosed Chickens and Goat: (Nature of

Residue--Metabolism ) : Laboratory Study No.: ABR- 87105. Unpublished study prepared by Ciba-Geigy Corp. 44 p.

40431355 Farrier, D. (1987) Study of Protease Released Metabolites in Selected Tissues of Lactating Goats Dosed with Carbon 14 -Atrazine: (Nature of

Residue--Metabolism ) : Laboratory Study No.: ABR-87109. Unpublished study prepared by Ciba-Geigy Corp. 130

40431356 Sim oneaux, B. (1986) Distribution and Characterization of Carbon 14 -Atrazine in a Chicken: (Nature of Residue--Metabolism ) : Laboratory Study No.:

ABR-86045. Unpublished study prepared by Ciba-Geigy Corp. 29 p.

40431357 Madrid, S. (1987) Metabolism of Car bon 14 -Atrazine in Laying Hens Dosed for Eight Consecutive Days at 50 ppm : (Nature of Residue-Metabolism ) : Laboratory

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ABR-87099. Unpublished study prepared by Ciba-Geigy Corp. 84 p.

40431364 Bade, T. (1986) Determ ination of Atrazine, G-28279, G-30033 and G-28273 Residues in Milk (including Sour Milk) using a Strong Cation Exchange Colum n Isolation and Cleanup: (Residue Anal ytical Method): Laboratory Study No.:

AG-496. Unpublished studyprepared by Ciba-Geigy Corp. 19 p.

40431365 Bade, T. (1987) Determ ination of Atrazine, G-30033, G-28279 and G-28273 Residues in Forage, Fodder, Grain and Gr ain Fractions from Grain Crops Using Capillary Gas Chrom a tography: (Residue Analytical Method): Laboratory Study

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40431369 Bade, T. (1985) Determ ination of Atrazine, G-28279, G-30033 and G-28273 Residues in Milk: (Residue Analyti cal Method): Laboratory Study No.: AG-463. Unpublished study prepared by Ciba-Geigy Corp. 19 p.

40431370 Bade, T. (1985) Determ ination of Atrazine, G-28279, G-30033 and G-28273 Residues in Beef Tissues (Blood, Muscle, Liver, Kidney, Fat): (Residue

186Analytical Method): Laboratory Study No.: AG-476. Unpublished study prepared by Ciba-Geigy Corp. 60 p.

40431383 Bade, T. (1987) Residues of Atrazine and Its Chlorom e tabolites in Grain Sorghum (Forage, Fodder, Grain and Gr ain Fractions) following Application of Aatritions (Storage Stability): Study No. lowing Application of Aatrex 4L, 80W or Nine-O Herbicide: (Magnitude of Residues): Laboratory Study No.:

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40431401 Bade, T. (1987) Residues of Atrazine and Its Chlorom e tabolites in Corn (Forage, Fodder, Grain and Grain Fractions) follo wing Application of Aatrex 4L, 80W or Nine-O Herbicide (Magnitude of Residues): Study No. ABR-87057. Unpublished

com p ilation prepared by Ciba-Geigy Corp. 947 p.

40431418 Bade, T. (1987) Residues of Atrazine and Its Chlorom e tabolites in Macadam ia

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40431420 Bade, T. (1987) Residue of Atrazine and its Chlorom e tabolites in W h eat and

W h eat Fractions Following Application of Aatrex Herbicide (Magnitude of Residues): Study No. ABR-87107. Unpublished study prepared in cooperation with Ciba-Geigy Corp and En-Cas A Analytical Laboratories. 130 p.

40431421 Cheung, M. (1987) Residue Stability Study of Atrazine and Chlorom e tabolites in Sweet Corn, Field Corn and Field Co rn Fractions under Freezer Storage Cond

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40431422 Bade, T. (1987) Residues of Atrazine and its Chlorom e tabolites in Poultry Tissues and Eggs from Laying Hens Following Adm i nistration of Atrazine (Magnitude of Residues): Study No. ABR-87059. Unpublished com p ilation prepared in cooperation with Ciba-Geigy Corp. and En-Cas Analytical

Laboratories. 109 p.

40431423 Bade, T. (1987) Magnitude of Residues of Atrazine and its Chlorom e tabolites in Poultry Tissues and Eggs from Laying Hens Fed Atrazine in their Diet (Ma4L,

80W or Nine-O Herbicide (Magnitude Atrazine in their Diet (Magnitude of Residues): Study No. ABR- 87102. Unpublished com p ilation prepared by Ciba-Geigy Corp. 34 p.

40431424 Bade, T. (1987) Residues of Atrazine and its Chlorom e tabolites in Dairy Tissues and Milk Following Adm i nistration of At razine (Magnitude Of Residues): Study

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18740431425 Bade, T. (1987) Magnitude of Residues of Atrazine and its Chlorom e tabolites in Meat and Milk of Beef and Dairy Cattle Fed Atrazine in Their Diet [ABR-87101, ABR-82065] (Magnitude of Residues): Study No. ABR-87101. Unpublished

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40431426 Cheung, M. (1987) Residue Stability Study of Atrazine, Sim a zine and

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com p ilation prepared by Ciba-Geigy Corp. 105 p.

40437501 Orr, G. (1987) A Sum m a ry of the Disposition, Kinetics and Metabolism of Atrazine in the Rat (General Metabolism ) : Laboratory/Study No. ABR-87116. Unpublished study prepared by Ciba-Geigy Corp. 44 p.

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40566301 Arthur, A. (1984) A Supplem ent to a Te ratology Study of Atrazine Technical in

New Zealand W h ite Rabbits. Unpublished study prepared by Ciba-Geigy Corporation. 4 p.

40566302 Infurna, R. (1984) A Supplem ent to a Teratology Study of Atrazine Technical in

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40566501 Brown, R.; Lail, L. (1988) Technical Atrazine: Product Chem istry: Laboratory Project ID PC-87-023. Unpublished study prepared by Ciba-Geigy Corporation. 267 p.

40614405 McCorm ick, C.C., Arthur, A.T., and Green, J.D. 1988. Sim azine-technical: 104 week oral chronic toxicity and carcinogenicity study in rats. Pharm aceutical Div., Ciba-Geigy. Laboratory report num ber: 2-011-09.

40629302 Hardisty, J. (1987) Supplem ent to Two- year Chronic Feeding/Oncogenicity Study

in Rats Adm i nistered Atrazine: 410-1102. Unpublished study prepared by Experim e ntal Pathology Laboratories, Inc. 316 p.

40629303 Rustum , A. 1988. Aerobic, aerobic/anaerobic, and sterile soil m e tabolism of

14 C-atrazine: Study No. HLA 6015-185. 165 p. Unpublished study prepared by

Hazleton Laboratories Am erica, Inc., Madison, W I ; subm itted by Ciba-Geigy Corp., Greensboro, NC.

40722301 Ceresa, C. (1988) Atrazine: Structural Chrom o som a l Aberration Test

188Micronucleus Test, Mouse: Study No. 871546. Unpublished study prepared by Ciba-Geigy Corp. 29 p.

40722302 Deparade, E. (1987) Diam inochlorotriazine: Gene Mutations Test: Salm onella/

Mam m a lian Mutagenicity Test: Study No. 871372. Unpublished study prepared by Ciba-Geigy Corp. 26 p.

40722303 Meyer, A. (1987) Diam inochlorotriazi ne: Tests for Other Genetoxic Effects: Autoradiographic DNA Repair Test on Hum a n Fibroblasts: Study No. 871371. Unpublished study prepared by Ciba-Geigy Corp. 81 p.

40722304 Deparade, E. (1988) Hydroxyatrazine: Gene Mutations Test: Salm onella/

Mam m a lian-Microsom e Mutagenicity Test: Study No. 871376. Unpublished study prepared by Ciba-Geigy Corp. 27 p.

40722305 Hertner, T. (1988). Tests for other genotoxic effects - auto-radiographic DNA repair test on rat hepatocytes. Ciba-Geigy, Basle, Switzerland. Laboratory report

num ber: 871374. January 22, 1988. Unpublished.

40888101 Meyer, A. (1988) Hydroxyatrazine: Tests for other genotoxic effects, autoradiographic DNA repair tests on hum an fibroblasts. Ciba-Geigy, Basle, Switzerland . Study No. 871375. January 11, 1988. Unpublished.

41065201 Giknis, M. (1989) A Teratology (Segm e nt II) Study in Rats: Atrazine Technical: Laboratory Study No. 882049. Unpublished study prepared by Ciba-Geigy Corp. 357 p

41065202 Giknis, M. (1989) A Teratology (Segm e nt II) Study in Rats: Hydroxyatrazine Technical: Laboratory Study No. 872202. Unpublished study prepared by CibaGeigy Corp. 362 p.

41065203 Hughes, J. R. 1986. The toxicity of atrazine, Lot No. FL-850612 to four species of aquatic plants. Lab. Study No. 267-28-1100. Prepared by Malcolm Pirnie,
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41065204 Parrish, R. 1978. Effects of atrazine on two freshwater and five m a rine algae. Lab. Study No. H82-500. Prepared by E G & G Bionom ics, Marine Research Laboratory, Pensacola, FL.; subm itted by Ciba-Geigy Corporation, Greensboro,

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41065205 Balu, K. 1989. Atrazine: Sum m a ry of surface water m onitoring data for atrazine. Laboratory Study No. EIR-89001. 484 p. Unpublished study prepared and

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41209801 Sim oneaux, B. (1989) Nature of Atrazine Residues in Plants: Project ID

189ABR-89060. Unpublished study prepared by Ciba-Geigy Corp. 170 p.

41209802 Thede, B. (1989) Nature of Atrazine Re sidues in Anim als: An Overview: Project

ID ABR-89053. Unpublished study prepared by Ciba-Geigy Corp. 46 p.

41209803 Sim oneaux, B. (1989) Atrazine - Natu re of the Residue: Characterization of Metabolites Present in Feces of an Atrazine Dosed Goat: Project ID ABR-89026. Unpublished study prepared by Ciba-Geigy Corp. 70 p.

41209804 Sim oneaux, B. (1989) Atrazine - Nature of the Residue: Further Characterization

of

Metabolites Present in Urine and Tissues of an Atrazine Dosed Goat: Project

ID ABR-89027. Unpublished study prepared by Ciba-Geigy Corp. 121 p.

41209805 Ballantine, L. (1989) Estim ated Dietary Exposure of Hydroxyatrazine Metabolites to Man: Atrazine: Project ID AB E-89067. Unpublished study prepared by Ciba-Gei study prepared by Ciba-Geigy Corp. 18 p.

41209806 Capps, T. (1989) Atrazine: Nature of Plant Metabolites in Anim als (Anim a l

Metabolism ) : Project ID ABR-89065. Unpublished study prepared by Ciba-Geigy Corp. 96 p.

41209807 Em rani, J. (1989) Fate of Corn Biosynthesized Metabolites of [Delta-Carbon 14]-Atrazine in Chickens: Project ID ABr-89006. Unpublished study prepared by Ciba-Geigy Corp. 42 p.

41209808 Sim oneaux, B. (1989) Fate of Biosynt hesized [Carbon 14]-Atrazine Metabolites in Lactating Goats: Project ID ABR-89054. Unpublished study prepared by Cibagy Corp. 18 p. hed study prepared by Ciba-Geigy Corp. 53 p.

41223001 Chetram

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41223003 Chetram

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41257901 Spare, W

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41257902 Spare, W

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41257905 Spare, W

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41257906 Spare, W

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12169. 57 p. Unpublished study prepared by Agrisearch Inc., Frederick, MD;

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41258601 Cheung, M. (1989) Sim azine, Atrazine, and Chlorom e tabolites: Residue Stability Study of Sim azine, Atrazine, and Chloro m e tabolites in Sweet Corn, Field Corn,

and Field Corn Fractions under Freezer Storage Conditions: Final Report: Laboratory Project IDABR-89032. Unpub lished study prepared by Ciba-Geigy Corp.83 p.

41258602 Cheung, M. (1989) Sim azine, Atrazine, and Chlorom e tabolites: Residue Stability Study of Sim azine, Atrazine, and Chlorom e tabolites in Apples and Apple Fraigy Corp. 53 p. lites in Apples and Apple Fractions under Freezer Storage Conditions: Final Report: Laboratory Project ID ABR-89033. Unpublished study prepared by Ciba-Geigy Corp. 73 p.

41258603 Cheung, M. (1989) Sim azine, Atrazine, and Chlorom e tabolites: Residue Stability Study of Sim azine, Atrazine, and Chlorom e tabolites in Dairy and Poultry Tissues, Milk, and Eggs under Freezer Storage Conditions: Final Report: Laboratory Project ID ABR- 89031. Unpublished st udy prepared by Ciba-Geigy Corp. 107

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41293501 Rudzki, M.; McCorm ick, G.; Arthur, A. (1989) 90-Day Oral Toxicity Study in Rats: Hydroxyatrazine: Lab Study Num b er 882146; MIN 882146; 89015. Unpublished study prepared by Ciba-Geigy Corp., Research Dept.,

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41392401 Thom pson, S.; Batastini, G.; Arthur, A. (1990) 13/52-W eek Oral Toxicity Study in Dogs: Lab Project Num b er: 872151. Unpublished study prepared by CibaGeigy Corp. 784 p.

41392402 Hum m e l, H.; Youreneff, M.; Giknis; et al. (1989) Diam inochlorotriazine: A Teratology (Segm e nt II) Study in Rats: Lab Project Num b er: 872177. Unpublished study prepared by Ciba-Geigy Corp. 428 p.

41397101 Ross, J. (1990) Atrazine - Sam p le Storage Stability Interval Sum

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41397102 Szorik, M. (1990) Ruggedness Testing of Atrazine Analytical Method AG-484

for the Determ ination of Atrazine and its Metabolites G-30033, G-28279, and G-2827ex 4L, 80W or Nine-O Herbicide: (Mag- 30033, G-28279, and G-28273 in Field Corn Forage, Field Corn Gr ain, and Sweet Corn (K + CW HR): Final Report: Lab Project Num b er: HLA 6012-298. Unpublished study prepared by

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41397103 Szorik, M. (1990) Ruggedness Testing of Atrazine Analytical Method AG-476

for the Determ ination of Atrazine and its Metabolites G-30033, G-28279, and G-28273 in Beef Muscle, Beef Fat, and Beef Blood: Final Report: Lab Project

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41423401 W illiam s , R. (1990) Multiresidue Method Testing of Atrazine, Sim a zine, and their Chloro-and Hydroxy-triazine Metabolites in Crops and Anim al Tissues: Lab Project ID: ABR-89010. Unpublished prepared by Ciba Geigy Corp. 130 p.

41479401 Ceresa, C. (1988) Hydroxyatrazine: Structural Chrom o som a l Aberration Test: Lab Project Num b er: 871373. Unpublished study prepared by Ciba-Geigy, Ltd. 32 p.

42041401 Putt, Arthur E. 1991. Atrazine 80% W P : Acute toxicity to daphnids ( Daphnia

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42041403 Chetram

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42041404 Hoberg, J. R. 1991. Atrazine technical: Toxicity to the duckweed Lemna gibba G3. SLI Rep. No. 91-1-3613. Prepared by Springborn Laboratories, Inc.,

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42041405 Speth, Robert M. 1991. Responses to the EPA review of the atrazine forestry field dissipation study at Oregon Cit y, Oregon. Supplem ent to MRID 40431340). Laboratory Project ID: ABR-91067. 45 p. Unpublished study prepared by CibaGeigy Corp., Greensboro, NC.; subm itte d by Ciba-Geigy Corp., Greensboro, NC.

19242043501 Slaven, R. (1991) Atrazine Technical: Response to Agency' s Letter of Septem ber 6, 1991:Atrazine Contam ination with 2,3,7,8,-TCDF. Unpublished study prepared by Ciba-Geigy Corp. 41 p.

42060701 Hoberg, J. R. 1991. Atrazine technical: Toxicity to the freshwater green alga Selenastrum capricornutum

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42085001 Thakur, A. (1991) Determ ination of Horm one Levels in Sprague-Dawley Rats Treated with Atrazine Technical: Final Report: Lab Project Num b er: 483-278. Unpublished study prepared by Hazleton W a shington, Inc. 1132 p.

42089901 Holbert, M. (1991) Acute Inhalation Toxi city Study in Rats: Atrazine Technical: Lab Project Num b er: 8079-91. Unpublished study prepared by Stillm eadow Inc. 23 p.

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43013207 Pettersen, J.; Richter, A.; Gilles, P. (1991) Diam inochlorotriazine (G-28273): 90­ Day Oral Toxicity Study in Rats: Lab Project Num b er: F-00006. Unpublished study prepared by Ciba-Geigy Corp. 450 p.

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43598630 Gold, B. (1995) Magnitude of Residues in Field Corn Forage, Silage-Stage Forage, Fodder, and Grain and Sweet Corn Ears and Forage Following Applications of AATREX 4L to Field Corn: Atrazine: Lab Project Num b ers: ABR-91070: 35-A-88. Unpublished study prep ared by Ciba-Geigy Corp. 563 p.

43598631 Gold, B. (1995) Magnitude of Resi dues in Grain Sorghum Forage, Hay, Silage-Stage Forage, Fodder, Grain, a nd Processed Grain Fractions Following Applications of AATREX 4L to Grain So rghum : Atrazine: Lab Project Num b er: ABR-91071: 34-88. Unpublished study prepared by Ciba-Geigy Corp. 503 p.

43598632 Selm an, F. (1995) Atrazine and Metolachlor--Magnitude of Residues in Soil and Grain Sorghum Following Applications of AATREX 4L and DUAL 8E W ith and

W i 6117-178: 51-91. Unpublished AATREX 4L and DUAL 8E W ith and W ithout the Addition of Acrysol G-110: Lab Project Num b ers: 02-HR-002-91 CA:

03-HR-004-91 MS: 04-HR-002-91 IL. Unpublished study prepared by Ciba-Geigy Corp. 326 p.

43598633 W u rz, R. (1995) Dietary Risk Exposur e Assessm ent for Atrazine: Lab Project

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20343598634 Clarkson, J.; Golden, K. (1995) Hum a n E xposure to Atrazine and Sim azine Via Ground and Surface Drinking W a ter: Lab Project Num b er: 2852.0410. Unpublished study prepared by Ciba-Geigy Corp. 1350 p.

43598637 Selm an, F. (1995) Sum m a ry of Assessm ent of W o rker Exposure for Atrazine in Response to the U.S. Environm ental Protection Agency Issuance of "The Triazine

Herbicides Position Docum e nt 1 Initiation of Special Review.": Lab Project

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43598638 Selm an, F. (1995) Assessm ent of W o rker Exposure for Atrazine in Response to

the U.S. Environm ental Protection Agency Issuance of "The Triazine Herbicides

Position Docum e nt 1 Initiation of Special Review.": Lab Project Num b er: ABR95038. Unpublished study prepared by Ciba-Geigy Corp. 115 p.

43598639 Kendall, R.; Solom a n, K.; Baker, D.; et al. (1995) Ecological Risk Assessm ent of

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43796001 Stubbs, D. (1995) Product Chem istry: Technical Atrazine: (Stability): (Final Report): Lab Project Num b er: PC-95- 032: 458-95F. Unpublished study prepared by Ciba-Geigy Corp. 35 p.

43934402 Pettersen, J.C. and Turnier, J.C. 1995. One-year chronic toxicity study with atrazine technical in rats. Ciba-Geigy Environm ental Health Center, Farm ington, CT. Lab Study no. F-00171.

43934403 Safe, S. (1995) Failure of chloro-s-triazine derived com pounds to induce estrogenic responses in vivo and in vitro . in Fundam e ntal Applied Toxicology (in Press).

43934404 Morseth, S. (1996) Evaluation of the Luteinizing Horm one (LH) in Fem a le Sprague-Dawley Rats--Pilot Study: Final Report: Lab Project Num b er: CHV

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43934405 Morseth, S. (1996) Evaluation of the Luteinizing Horm one (LH) in Fem a le Sprague-Dawley Rats--Method Validation: Final Report: Lab Project Num b er: CHV 2386-110: 6791F: 2386-110. Unpublished study prepared by Corning Hazleton Inc. (CHV). 32 p.

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204Atrazine-Exposed Fem a le Sprague-Dawley Rats: Interim Report: Lab Project

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43934407 Hui, X.; W e ster, R.; Maibach, H. (1995) Disposition of Atrazine in Rhesus Monkey Following Intravenous Adm i nistration: Interim Report: Lab Project

Num b er: UCSF 95SU04: 333-95. Unpublished study prepared by University of California. 63 p.

43934408 Maibach, H. (1996) Disposition of Atrazine in Rhesus Monkey Following

Intravenous Adm i nistration: Interim Report: Lab Project Num b er: ABR-95131: 333-95. Unpublished study prepared by Ciba-Geigy Corp. and University of California. 59 p.

43934411 Hackett, D.; Bray, L. (1996) Updated Dietary Exposure Assessm ent for Atrazine: Lab Project Num b er: ABR-96009. Unpublished study prepared by Ciba-Geigy Corp. 48 p.

43934412 Thalacker, F. (1996) Determ ination of Transfer Rate and Nature of the Residue(s)

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43934421 Benjam in, R. (1996) Characterization of Selenastrum Capricornutum Response to Episodic Atrazine Exposure: La b Project Num b er: 09524: TIW ET 09542:

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43934422 Drewing, L. (1996) Supplem ent to Ciba' s Benefits Analysis of Atrazine and

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44008601 Delzell, E, I. Brill, and C. Beall. (1996). A follow-up Study of W o rkers at the Ciba-Geigy St. Gabriel Plant. Laborat ory Study No. Supplem ental Docum e nt No.

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44152102 Morseth, S. (1996) Evaluation of the Luteinizing Horm one (LH) Surge in Atrazine-Exposed Fem a le Sprague-Dawley Rats--(Final) 6-Month Interim Report: Lab Project Num b er: CHV 2386-111: 2386-111: 6791E. Unpublished study prepared by Corning Hazleton Inc. 727 p.

44152104 Sim pkins, J. (1996) Evaluation of a Horm onal Mode of Action for Mam m a ry Carcinogenesis of the Chlorotriazine Herbicides: Second Concensus Panel Report. Unpublished study prepared by Ciba-Geigy Corp. 37 p.

44152105 Consensus Panel (1995) W e ight of the Evidence on the Oncogenic Potential of

206Atrazine: Consensus Panel Report. Unpublished study. 38 p.

44152106 An Updated Assessm ent of W o rker Exposure for Atrazine in Response to the U.S.

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44152108 Selm an, F.B. (1996). Supplem ental Data and Evaluation of Exposure to Lawn Care Operators Using Atrazine in the Southern United States. Supplem ent to
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44152109 Selm an, F.B. and L. Rosenheck. (1996). Evaluation of the Potential Exposure of

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44152110 Bodalbhai, L. (1996) Analytical Met hod for the Determ ination of Residues of Atrazine, G-30033, G-28279, and G-28273 in Urine by Gas

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44152111 Honeycutt, R.C., Bennett, R.M. and DeGeare, M.A. (1996). Evaluation of the Potential Exposure of W o rkers to Atrazine during Com m e rcial Mixing, Loading, and Spray Application to Corn (EPA-Subpa rt U) -- Biological Field Phase: Final Report: Lab Project Num b er: 178-95: 95-501HE: 95-517. Unpublished study prepared by Ciba Crop Protection [now Syngenta]. 687 pages, 2 volum es.

44152113 Hui, X.; W e ster, R.; Sim oneaux, B.; et al. (1996) Disposition of Atrazine in Rhesus Monkey Following Oral Adm i ni stration: Lab Project Num b er: ABR96094: UCSF 96SU01: 306-96. Unpublished study prepared by University of California, San Francisco a nd Ciba Crop Protection. 171 p.

44152114 Hui, X.; Gilm an, S.; Sim oneaux, B.; et al. (1996) In vivo Percutaneous Absorption of Atrazine in Man: Lab Project Num b er: ABR-96067: BDH-081-2: H832-11835­

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44152117 Boyette, S. (1996) Atrazine--Magnitude of the Residues In or On Corn: (Final Report): Lab Project Num b er: ABR-96087: 25-96: 101930. Unpublished study prepared by Ciba-Geigy Corp. 211 p.

44152118 Boyette, S. (1996) Atrazine--Magnitude of the Residues In or On Grain Sorghum : Lab Project Num b er: ABR-96088: 26- 96: 101930. Unpublished study prepared by Ciba-Geigy Corp. 286 p.

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44152120 Thalacker, F.; Ash, S. (1996) (Carbon 14)-Atrazine: Nature and Magnitude of the Hydroxy-triazine and Chlorotriazine Residues in Sorghum Following a

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44152121 Thalacker, F.; Ash, S. (1996) (Carbon 14)-Atrazine: Nature and Magnitude of the Hydroxy-triazine and Chlorotriazine Residues in Corn Following a

Pre-em ergence Application at 2 lb. ai/A: Lab Project Num b er: CHW 6117-335:

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44152122 Clarkson, J.; Hines, N.; Tierney, D.; et al. (1996) Hum a n Exposure to Atrazine

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44152123 Tierney D and Balu K. 1996. Sum m a ry of Voluntary Atrazine Monitoring Program at Selected Com m unity W a ter System s. October 29, 1996. Subm itted by

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44152124 Tierney, D.; Balu, K. (1996) Sum m a ry of Sam p ling Methods for Estim ating

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44152125 Sielken, R.; Bretzlaff, R.; Valdez-Flor es, C. (1996) Risk Characterization for

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20844152126 Giddings, J.; Hall, L.; Kendall, R.; et al. (1996) Beyond the Probabilistic Approach: Risk Assessm ent of Atrazine in North Am erican Surface W a ters: Supplem ent to MRID 43934419. Unpublished study prepared by Ecorisk, Inc. 54

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44152127 Hill, E.; Crouse, K. (1996) The Role of Atrazine in Managing W eed Biotypes Resistant to ALS-Inhibitor Herbicides. Unpublished study prepared by Ciba Crop Protection. 87 p.

44222601 Balu, K.; Holden, P. (1996) Ciba/State Ground-W a ter Monitoring Study for Atrazine and Its Major Degradation Products in the United States: Am endm ent to the Final Report--MRID 43934414: La b Project Num b er: 174-91: 242.01: CIGNC01E-5. Unpublished study prepared by W a terborne Environm ental, Inc.; Ciba Crop Protection; and Alta Analytical Lab, Inc. 13 p.

44222602 Balu, K.; Holden, P. (1997) Ciba/State Ground-W a ter Monitoring Study for Atrazine and Its Major Degradation Products in the United States: Second

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44256501 Delzell, E.; Sathiakum ar, N. (1996) An Updated Follow-up Study of W o rkers at the Ciba-Geigy McIntosh Plant: Final Report. Unpublished study prepared by University of Alabam a at Birm ingham

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44256502 Delzell, E.; Sathiakum ar, N. (1996) A Com b ined Analysis of Mortality Am ong W o rkers at the Ciba-Geigy Corporation' s McIntosh and St. Gabriel Plants--An Update. Unpublished study prepared by University of Alabam a at Birm ingham

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44315401 Sim pkins, J. (1997) Evaluation of a Horm onal Mode of Action for Mam m a ry Carcinogenesis of the Chloro-s-triazine Herbicides: Third Consensus Panel Report. Unpublished study prepared by Novartis Crop Protection, Inc. 27 p.

44315402 Safe, S.; McDougal, A.; W ilson, C. (1997) Induction of estradiol 2-hydroxylase activity in MCF-7 hum an breast cancer cells by pesticides and carcinogens.

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44315405 Sim oneaux, B. (1996) Disposition of At razine in Rhesus Monkey Following Oral

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44315406 Bray, L.; Boyette, S.; Breckenridge, C. et al. (1997) Sum m a ry of the Nature and Magnitude of Atrazine Residues on Corn and Sorghum Grain, Forage and Fodder and the Basis for the Dietary Risk Assessm ent. Unpublished study prepared by Novartis Crop Protection, Inc. 17 p.

44315407 Bray, L. (1997) Revised Dietary A ssessm ent for Atrazine Including Two Exposure Scenarios: Lab Project Num b er: ABR-97064: 396-97. Unpublished study prepared by Novartis Crop Protection, Inc. 193 p.

44315408 Thalacker, F. (1996) (Carbon-14)-Atrazine: Nature and Magnitude of the Hydroxy-triazine and Chlorotriazine Residues in Corn Following a

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44315409 Thalacker, F.; Ash, S. (1996) 14 C-Atrazine: Nature and Magnitude of the Hydroxy-triazine and Chlorotriazine Residues in Sorghum Following a

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44315410 Boyette, S. (1996) Atrazine--Magnitude of the Residues in or on Corn:

Am endm ent 1: Lab Project Num b er: ABR-96087: 25-96: 101930. Unpublished study prepared by Novartis Crop Protection, Inc. 533 p. {OPPTS 860.1500}.

44315411 Boyette, S. (1996) Atrazine-Magnitude of the Residues in or on Grain Sorghum : Am endm ent 1: Lab Project Num b er: A BR-96088: 26-96: 26-96-A. Unpublished study prepared by Novartis Crop Protection, Inc. 366 p. {OPPTS 860.1500}.

44315412 Lin, K. (1997) Validation of Analytical Method AG-484A for the Determ ination of Residues of Atrazine, G-30033, G-28279 and G-28273 in or on Corn and Sorghum : Lab Project Num b er: A BR-97056: 300-97: AG-484A. Unpublished study prepared by Novartis Crop Protection, Inc. 141 p. {OPPTS 860.1340}.

44315413 Bray, L. (1997) Rationale for the Dairy Cattle Diet Utilized in the Revised

210Dietary Exposure Assessm ent for Atrazine and Sim azine: Lab Project Num b er: ABR-97067: 400-97. Unpublished study prepar ed by Novartis Crop Protection, Inc. 15 p.

44315414 Clarkson, J.; Hines, N.; Tierney, D. et al. (1997) Hum a n Exposure to Atrazine and

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44315417 Brooks, R.; Crouse, K.; Hill, E. et al. (1997) Supplem ent to Novartis' Benefits Analysis of Atrazine and Sim azine: Additional Inform ation on W eed Control,

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44488801 Lail, L. (1998) Technical Atrazine: Product Chem istry (Prelim inary Analysis): Lab Project Num b er: 206-98: ASR-073: 145-94. Unpublished study prepared by Novartis Crop Protection, Inc. 17 p. {OPPTS 830.1700}

44518401 Van Kam p en, W

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44544701 Morseth, S. (1998) Chronic (12-24 M onth) Study in Rats with Atrazine Technical. Study No. 2386-108. Unpublished study prepared by Covance Laboratories Inc. 2251 p.

44590401 Hackett, A. (1998) 1997 Annualized Mean Concentrations (AMCs) and 1997 and Early 1998 Analytical Results: Surface W a ter Monitoring Program : Monstanto Study No. 94-27-R-3. Unpublished study prepared by Monsanto Co. and the Acetochlor Registration Partnership. 92 p.

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44597602 Boyette, S. (1998) Atrazine--Magnitude of the Residues in or on Corn

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44597604 Selm an, F.B. (1998). Com p arison of Exposure Assessm ents to Atrazine and

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44597605 Selm an, F.B. (1998). Evaluation of the Potential Internal Dose of Atrazine to

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44723701 Bachm a nn, M. (1994) 3 Month Oral Toxicity Study in Rats (Adm inistration in Food) (Atrazine): Lab Project Num b er: 931063: 351270. Unpublished study prepared by Novartis Crop Protection, AG. 392 p.

44856901 Brady, J. (1999) Validation Study of an Atrazine Im m unoassay for Drinking

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44883601 Prochaska, L.M. (1999). Dissipation of Dislodgeable Foliar Residues of

Atrazine on Field Corn. Stewart Pr oject Num b er: SARS-97-54; W ildlife International Project Num b er: 468C-105. Unpublished study prepared by Stewart Agricultural Research Services. 131 pages.

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44958001 Hofen, J. (1999) Determ ination of Transferable Residues on Turf Treated with

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44958801 Rosenheck, L. (1999). Determ ination of Transferable Turf Residues on Turf Treated with Atrazine Applied in a Gr anular Fertilizer Form ulation. Novartis Laboratory Num b er 805-98. ABC La boratory Num b er 45035. Unpublished Study prepared by Novartis [now Syngenta]. 183 pages.

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45475102 Tierney, D.; Christensen, B. (2001) Atr azine and Total Chloro-triazine (TCT) Concentrations for Raw and Finished W a ter from Com m unity W a ter System s (CW S ) on Surface W a ter that Participated in the Syngenta Voluntary Monitoring Program s, 1993-2000: Final Report: Lab Project Num b er: 1265-99: 00103. Unpublished study prepared by Syngenta Crop Protection and En-fate, LLC. 18 p.

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45517301 Rosenheck, L. (2001) Atrazine Use in Southern Turf: Additional Inform ation For

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45545301 Burnett, D. (1992) Response to the EPA Request for Additional Inform ation for the Aqueous Photolysis of (Carbon 14)-A trazine Under Natural and Artificial Light: Lab Project Num b er: 534-92. Unpublished study prepared by Syngenta Crop Protection, Inc. 17 p.

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45545304 Yokley, R. (2001) Re-Sam pling of Dom e stic Rural Drinking W a ter W e lls: Atrazine: Final Report: Lab Project Num b er: 1697-01. Unpublished study prepared by Syngenta Crop Protection, Inc. 61 p.

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22745599702 Brooks, R.; Crouse, K.; Drewing, L. et al. (1995) Benefits/Alternatives Sum m a ry for Atrazine and Sim azine. Unpublished study prepared by Ciba Crop Protection. 28 p.

45599703 Parshley, T. (1995) Farm ing Trends and Practices: Atrazine and Sim azine. Unpublished study prepared by Ciba Crop Protection. 188 p.

45599704 Parshley, T. (1995) Sustainable Agriculture: The Potential of Non-Chem ical

W eed Control Methods as Substitutes for Herbicides in U.S. Corn Production. Unpublished study prepared by Ciba Crop Protection. 68 p.

45599705 Parshley, T. (1995) Environm ental Be nefits of Atrazine and Sim a zine. Unpublished study prepared by Ciba Crop Protection. 185 p.

45599706 Parshley, T. (1995) The Role of Atr azine and Sim azine in W eed Resistance Managem e nt. Unpublished study prepared by Ciba Crop Protection. 143 p.

45599707 Parshley, T. (1995) Econom ic Evaluati ons: Lost Benefits from Atrazine or Triazine Herbicide Cancellations (U.S.Im p act). Unpublished study prepared by Ciba Crop Protection. 60 p.

45599708 Parshley, T. (1995) Econom ic Review of Past Atrazine and Triazine Herbicide

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45599709 Parshley, T. (1995) Com p arative Analysis of Alternatives in Corn. Unpublished study prepared by Ciba Crop Protection. 1056 p.

45599710 Parshley, T. (1996) Com p arative Analysis of Alternatives in Sorghum

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45599711 Parshley, T. (1995) Benefits of At razine in Ecofallow. Unpublished study prepared by Ciba Crop Protection. 613 p.

45599712 Parshley, T. (1995) Benefits of Atrazi ne and Sim azine in Turf and Ornam e ntal Nurseries. Unpublished study prepared by Ciba Crop Protection. 165 p.

45599713 Parshley, T. (1995) Benefits of Atrazi ne and Sim azine in Conifers. Unpublished

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45622302 Giddings, J.; Anderson, T.; Hall, L. et al. (2002) Supplem ent to “Aquatic Ecological Risk Assessm ent of Atrazine -A Tiered, Probabilistic Approach.” Including Responses to EPA Com m e nts: Final Report: Lab Project Num b er: 709­

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45622303 Burnett, G.; Chen, W

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45622308 Riggs, M.; McMichael, B.; Clayton, A.; et al. (2002) Long-Term (1994-2000) Trend Analysis of Atrazine Concentrations from 127 Midwestern W a ter Bodies: Lab Project Num b er: 07779.002: 2694-01. Unpublished study prepared by Research Triangle Institute. 41 p.

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45622310 Rosenheck, L. (2002) Determ ination of De rm al Transfer Efficiency of Granular

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45622311 Rosenheck, L. (2002) Children' s Residential Exposure and Risk Assessm ent to Atrazine Treated Turf Using Hand Pre ss Transfer Efficiency: Lab Project
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45629401 W a lls, C.; Scrafford, C.; Barraj, L. (2002) Probabilistic Assessm ent of Drinking
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45711302 Breckenridge, C.; Stevens, J.; Pastoor , T. (2002) The Selection of Endpoints, Application of FQPA Uncertainty Factor s and Risk Extrapolation at the 99.9th Percentile: Atrazine: Lab Project Num b er: 1776-02. Unpublished study prepared by Syngenta Crop Protection, Inc. 21 p.

45711304 Hertl, P. (2002) Occurrence of Atrazine in Com m unity W a ter System s on Groundwater and Rural W e lls in High Atrazine Use Areas: Final Report: Lab Project Num b er: 1778-02. Unpublished study prepared by Syngenta Crop Protection, Inc. 58 p.

45711305 Breckenridge, C.; Hertl, P. (2002) An Analysis of the Trends in Atrazine Concentration in Raw and Finished Dri nking W a ter in High Atrazine Use Areas: Lab Project Num b er: 1777-02. Unpublished study prepared by Syngenta Crop Protection, Inc. 43 p.

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45722700 Acetochlor Registration Partnership (2002) Subm ission of Environm ental Fate Data in Support of the Registration of Acetochlor. Transm ittal of 1 Study.

45728401 van W e senbeeck, I.; Guzm an, N.; Fuhrm a n, J.; et al. (2002) State Ground W a ter Monitoring Program for Acetochlor and Other Corn Herbicides--Part 9: Final Study Report: Lab Project Num b er: ARP-GW M-02: 852-577: ACET-95-GW -02. Unpublished study prepared by LFR Levine-Fricke and Monsanto. 121 p.

45730200 Acetochlor Registration Partnership (2002) Subm ission of Environm ental Fate Data in Support of Acetochlor. Transm ittal of 1 Study.

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252Appendix E: GENERIC DATA CALL-IN

Note that a com p lete Data Call-In (DCI), w ith all pertinent instructions, will be sent to
registrants under separate cover.

253Generic DCI Page 1 of 9

254Generic DCI Page 2 of 9

255Generic DCI Page 3 of 9

256Generic DCI Page 4 of 9

257Generic DCI Page 5 of 9

258Generic DCI Page 6 of 9

259Generic DCI Page 7 of 9

260Generic DCI Page 8 of 9

261Generic DCI Page 9 of 9

262263264Appendix F: PRODUCT SPECIFIC DATA CALL-IN

Note that a com p lete Data Call-In (DCI), w ith all pertinent instructions, will be sent to registrants under separate cover.

265Product Specific DCI Page 1 of 7

266Product Specific DCI Page 2 of 7

267Product Specific DCI Page 3 of 7

268Product Specific DCI Page 4 of 7

269Product Specific DCI Page 5 of 7

270Product Specific DCI Page 6 of 7

271Product Specific DCI Page 7 of 7

272273274Appendix G: EPA'S BATCHING OF ATRAZ INE PRODUCTS FOR MEETING ACUTE TOXICITY DATA REQUIREMENTS FOR REREGISTRATION

In an ef f

o rt to reduce the tim e, resources and num ber of anim als needed to f u lf ill the acute toxicity data requirem e nts for reregistration of products containing ATRAZ INE as the active ingredient, the Agency has batched products which can be considered sim ilar for purposes of acute toxicity. Factors considered in the sorting process include each product' s active and inert ingredients (identity, percent com position and bi ological activity), type of form ulation (e.g.,

em ulsifiable concentrate, aerosol, wettable pow der, granular, etc.), and labeling (e.g., signal word, use classification, precautionary labeling, etc. ). Note that the Agency is not describing batched products as "substantially sim ilar" since som e products within a batch m a y not be
considered chem ically sim ilar or have identical use patterns.

Using available inform ation, batching has been accom p lished by the process described in the preceding paragraph. Notwith-standing the batching process, the Agency reserves the right to require, at any tim e, acute toxicity data for an individual product should the need arise.

Registrants of products within a batch m a y choose to cooperatively generate, subm it or cite a single battery of six acute toxicological studies to represent all the products within that batch. It is the registrants' option to participate in the process with all other registrants, only

som e of the other registrants, or only their own products within a batch, or to generate all the required acute toxicological studies for each of their own products. If a registrant chooses to generate the data for a batch, he/she m u st use one of the products within the batch as the test

m a terial. If a registrant chooses to rely upon previously subm itted acute toxicity data, he/she

m a y do so provided that the data base is com p lete and valid by today' s standards (see acceptance criteria attached), the f o rm ulation tested is considered by EPA to be sim ilar f o r acute toxicity,
and the form ulation has not been significantly altered since subm ission and acceptance of the acute toxicity data. Regardless of whether new data is generated or existing data is referenced, registrants m u st clearly identif y the test m a teri al by EPA Registration Num b er. If m o re than one
confidential statem ent of form ula (CSF) exists for a product, the registrant m u st indicate the
form ulation actually tested by identifying the corresponding CSF.

In deciding how to m eet the product specific data requirem e nts, registrants m u st follow the directions given in the Data Call-In Notice and its attachm e nts appended to the RED. The DCI Notice contains two response form s which are to be com p leted and subm itted to the Agency within 90 days of receipt. The first form , "Data Call-In Response," asks whether the registrant will m eet the data requirem e nts for each product. The second form , "Requirem e nts Status and Registrant' s Response," lists the product specific data required for each product, including the standard six acute toxicity tests. A registrant who wishes to participate in a batch m u st decide whether he/she will provide the data or depend on som e one else to do so. If a registrant supplies the data to support a batch of products, he/she m u st select one of the following options: Developing Data (Option 1), Subm itting an Exis ting Study (Option 4), Upgrading an Existing Study (Option 5) or Citing an Existing Study (Op tion 6). If a registrant depends on another' s data, he/she m u st choose am ong: Cost Sharing (O ption 2), Offers to Cost Share (Option 3) or Citing an Existing Study (Option 6). If a registrant does not want to participate in a batch, the choices are Options 1, 4, 5 or 6. However, a registrant should know that choosing not to participate in a batch does not preclude other registrants in the batch from citing his/her studies and offering to cost share (Option 3) those studies.

275One hundred and thirty-five products were found which contain Atraz i ne as the active ingredient. These products have been placed into fourteen batches and a "No Batch" category in accordance with the active and inert ingredients and type of form ulation. Furtherm ore, the following bridging strategies are deem ed acceptable for this chem ical:

• B atch 11: EPA Reg. No. 524-493 and 524-497 m a y cite the data generated with EPA Reg. No. 524-510.

• B atch 13: Each product in this Batch should generate their own prim ary eye irritation study utilizing the fertilizer with the highest levels of nitrogen.

• B atch 14: Each product in this Batch should generate their own prim ary eye irritation study utilizing the fertilizer with the highest levels of nitrogen.

• N o Batch: Each product in this Batch should generate their own data.

NOTE: The technical acute toxicity values included in this docum ent are for inform ational purposes only. The data supporting these values m a y or m a y not m eet the current acceptance
criteria.

Batch 1 E PA Reg. No. % Active Ingredient

100-529 98.00

11603-32 98.81

19713-7 97.00

19713-375 97.00

34704-784 97.00

35915-6 98.50

62719-456 97.60

Batch 2 E PA Reg. No. % Active Ingredient

100-585 90.0

1381-159 90.0

1386-660 90.0

2749-485 90.0

5905-522 90.0

9779-253 90.1

11773-13 90.0

276Batch 2 E PA Reg. No. % Active Ingredient

19713-76 90.0

19713-499 90.0

33270-9 90.0

34704-622 90.0

34704-689 90.0

35915-3 90.0

42750-53 90.0

55467-4 90.0

59639-106 90.0

62719-313 90.0

66222-37 90.0

Batch 3 E PA Reg. No. % Active Ingredient

9779-254 80.0

34704-490 80.0

51036-9 80.0

51036-159 80.0

Batch 4 E PA Reg. No. % Active Ingredient

19713-80 53.48

19713-291 53.48

Batch 5 E PA Reg. No. % Active Ingredient

100-497 43.5

534-97 43.5

829-268 43.0

1381-158 43.0

277Batch 5 E PA Reg. No. % Active Ingredient

1386-647 43.0

2749-336 43.0

5905-470 43.0

7401-318 43.0

9404-72 43.0

9779-255 43.0

11773-1 43.6

19713-11 43.0

19713-498 43.0

33270-10 43.5

34704-69 43.0

34704-690 43.0

35915-4 43.0

42750-44 43.0

42750-45 43.0

48273-11 43.5

51036-158 43.0

55467-5 43.5

62719-312 43.0

66222-36 43.6

Batch 6 E PA Reg. No. % Active Ingredient

100-817 Atrazine: 33.7

S-Metolachlor: 26.1

100-886 Atrazine: 33.7

S-Metolachlor: 26.1

278Batch 7 E PA Reg. No. % Active Ingredient

352-600 Atrazine: 28.4

Dim e thenam id: 24.8

7969-146 Atrazine: 28.4

Dim e thenam id: 24.8

Batch 8 E PA Reg. No. % Active Ingredient

7969-136 Atrazine: 22.23

Dicam ba K Salt: 13.42

42750-41 Atrazine: 22.23

Dicam ba K Salt: 13.42

51036-307 Atrazine: 22.23

Dicam ba K Salt: 13.42

70907-16 Atrazine: 21.92

Dicam ba K Salt: 13.45

Batch 9 E PA Reg. No. % Active Ingredient

264-477 Atrazine: 21.62

Brom oxynil Octanoate: 15.74

9779-348 Atrazine: 21.62

Brom oxynil Octanoate: 15.74

51036-255 Atrazine: 21.62

Brom oxynil Octanoate: 15.74

71368-27 Atrazine: 21.62

Brom oxynil Octanoate: 15.74

279Batch 10 EPA Reg. No. % Active Ingredient

51036-363 Atrazine: 25.0

Bentazon: 27.0

60063-18 Atrazine: 25.0

Bentazon: 27.0

Batch 11 EPA Reg. No. % Active Ingredient

524-493 Atrazine: 16.1

Acetochlor: 21.5
Glyphosate: 8.1

524-497 Atrazine: 16.2

Acetochlor: 21.6
Glyphosate: 8.2

524-510 Atrazine: 15.9

Acetochlor: 21.2
Glyphosate: 15.9

Batch 12 EPA Reg. No. % Active Ingredient

19713-513 Atrazine: 16.6

Acetochlor: 24.8

62719-371 Atrazine: 16.6

Acetochlor: 24.8

Batch 13 EPA Reg. No. % Active Ingredient

538-18 1.055

538-163 0.600

538-229 1.320

538-234 0.600

280Batch 13 EPA Reg. No. % Active Ingredient

9198-186 1.110

Batch 14 EPA Reg. No. % Active Ingredient

769-943 0.92

7138-14 0.90

7401-336 0.83

8660-12 1.16

8660-18 1.18

8660-32 0.58

8660-41 0.92

8660-187 0.63

8660-204 0.92

8660-223 1.05

8660-224 0.91

8660-245 0.42

9198-153 0.92

9404-51 0.92

9404-55 0.79

9404-56 1.50

9404-80 0.57

9404-81 1.28

9404-82 1.15

9779-359 0.92

9779-360 0.80

10404-39 0.80

10404-94 1.05

10404-95 0.45

10404-96 0.92

34704-822 0.92

281Batch 14 EPA Reg. No. % Active Ingredient

35512-14 0.80

35512-34 0.57

35512-41 1.22

35512-42 0.44

35512-46 0.92

59144-32 1.16

No Batch E PA Reg. No. % Active Ingredient

100-827 Atrazine: 28.7

S-Metolachlor: 35.8

100-928 Atrazine: 23.3

Flum etsulam : 1.0

S-Metolachlor: 29.1

100-956 Atrazine: 74.93

Prosulfuron: 1.78

100-962 Atrazine: 25.7
Glyphosate: 18.0

239-2618 14.0

241-353 Atrazine: 32.54

Im azethapyr: 4.36

264-573 Atrazine: 43.2

Isoxaflutole: 3.2

264-668 Atrazine: 33.42

Glufosinate-am m onium : 10.00

270-288 23.6

352-585 Atrazine: 86.78

Nicosulfuron: 1.34

Rim s ulfuron: 1.34

524-329 Atrazine: 16.3

Alachlor: 27.2

282No Batch E PA Reg. No. % Active Ingredient

524-418 Atrazine: 15.3

Alachlor: 27.05

524-480 Atrazine: 18.3

Acetochlor: 46.3

524-485 Atrazine: 26.9

Acetochlor: 33.4

524-509 Atrazine: 20.9
Glyphosate: 20.9

524-511 Atrazine: 14.5

Acetochlor: 29.0

3125-523 Atrazine: 50.5

Flufenacet: 19.6

Metribuzin: 4.9

7969-192 Atrazine: 35.3

Dim e thenam id-P: 18.2

7969-200 Atrazine: 29.5

Dim e thenam id-P: 24.1

19713-6 80.0

19713-171 Atrazine: 21.42

Sim azine: 21.41

34704-728 Atrazine: 25.00

2,4-D: 16.58

42750-50 Atrazine: 21.62

Brom oxynil: 15.74

62719-368 Atrazine: 21.1

Acetochlor: 31.6

283284Appendix H: ATRAZ INE MONITORED WATERSHEDS

LA1047002 Iberville W a ter W o rks District #3 Louisiana

MO1010204 Dearborn M issouri

IL1170400 Gillespie Illinois

KY0280267 Marion W a ter Departm e nt Kentucky

KY0710247 Lewisburg W a ter W o rks K entucky

IA5903011 Chariton Municipal W a ter W o rks I owa

MO2010112 Bucklin Missouri

IN5299001 Batesville W a ter Utility Indiana

285