Current as of January 2013
One of the most widely used agricultural pesticides in the U.S., atrazine may be applied before and after planting to control broadleaf and grassy weeds. It is used primarily on corn, sorghum, and sugarcane, and is applied most heavily in the Midwest. Atrazine is used to a lesser extent on residential lawns, particularly in Florida and the Southeast. Go to more information about atrazine.
On this page you will find:
- Atrazine Evaluation Process (began fall 2009)
- Triazine Cumulative Risk Assessment (2006)
- Atrazine Post-RED Results
Since we concluded our last evaluation of atrazine in 2003, we have evaluated close to 150 published studies investigating a wide array of effects potentially relevant to human health risk assessment. Given this significant new body of scientific information as well as the documented presence of atrazine in both drinking water sources and other bodies of water, we determined it appropriate to review the state of the science in light of the new research and to ensure that the agency’s regulatory decisions continue to protect public health and the environment.
This review is based on transparency and sound science, including independent scientific peer review. Since 2003 our oversight of atrazine has always been dynamic, not static, to ensure continued safety.
Scientific Peer Review—Human Health
To be certain that the best available science is used to inform its atrazine risk assessments, and to ensure transparency, we have sought advice on key aspects of the science evaluation from the independent FIFRA Scientific Advisory Panel (SAP). SAP meetings are open to the public, and we encourage all interested parties to participate in these meetings.
From 2010-2011, we presented information to the SAP on four occasions to invite independent scientific peer review on over 150 new studies concerning atrazine and its potential impact on human health. During the July 2011 FIFRA SAP meeting, the Panel commented that – while there are still areas of uncertainty – the agency’s scientific bases for its regulation of atrazine are robust and ensure prevention of exposure levels that could lead to reproductive effects in humans.
Reproductive effects are the most sensitive effects observed in atrazine toxicity tests and, as such, our efforts to regulate the pesticide to protect against these effects through drinking water exposure will protect against all other effects that occur at higher levels. We plan to take the recommendations from the SAP’s report on the July 26-29, 2011 meeting as well as all previous SAPs into account as we update the state of the science on the health effects of atrazine. The scientific information will be thoroughly considered in registration review of atrazine, scheduled to begin in 2013.
Scientific Peer Review—Ecological Assessment
On June 12-15, 2012, we held a FIFRA SAP meeting to review the agency’s problem formulation for the environmental fate and ecological risk assessment for atrazine. During this SAP, we presented a refined methodology for determining the magnitude and frequency of atrazine exposures below which significant changes in aquatic plant community structure, function and productivity are not expected. We also presented our review of atrazine studies with amphibians published in the open literature since 2007.
In general, during the June 2012 FIFRA SAP meeting, the Panel recommended that EPA further analyze existing data and proposed that additional studies be conducted to further refine the environmental fate and ecological risk assessment for atrazine. The Panel also recommended some refinements and alternative approaches for us to consider when interpreting uncertainty in atrazine water monitoring data. We plan to take the recommendations from this SAP as well as previous SAPs into account as we update the state of the science for the atrazine registration review beginning in 2013.
All documents for the June 2012 SAP meeting, including the FIFRA SAP Meeting Report & Transcript, background documents and public comments, are available at www.regulations.gov in docket EPA-HQ-OPP-2012-0230.
Registration Review to Begin in 2013
Atrazine will begin registration review, EPA’s periodic re-evaluation program for existing pesticides, in mid-2013. The registration review preliminary work plan will be available in the public docket for a 60-day comment period and will include a summary of what is known about atrazine as well as a list of anticipated data needs. For more information on registration review please visit EPA’s website https://www.epa.gov/oppsrrd1/registration_review/index.htm.
If at any time atrazine data raise new risk concerns, we will modify our regulation of atrazine as appropriate.
EPA’s triazine cumulative risk assessment considered the combined effects of atrazine and simazine, two closely related triazine herbicides. In 2006, we concluded that cumulative exposures to these pesticides through food and drinking water are safe and meet the rigorous human health standards set forth in the Food Quality Protection Act (FQPA). This assessment showed that the levels of atrazine and simazine that Americans are exposed to in their food and drinking water, combined, are below the level that would potentially cause health effects.
This section provides results to date from the programs, activities, and studies required by EPA’s Atrazine Reregistration Eligibility Decision (RED) (PDF) (323 pp, 187M, about PDF) of 2003, including:
- Office of Pesticide Programs’ Monitoring in Community Water Systems
- Ecological Watershed Monitoring Program
Atrazine Monitoring Data
Currently, an intensive monitoring program to look for atrazine residues in drinking water from approximately 30 community water systems (CWS) is ongoing. These systems, located primarily in the Midwest, are among the most vulnerable to atrazine exposure.
Through our review of data from this program, we have confirmed that none of the systems have exceeded our level of concern, a 90-day average of 37.5 parts per billion (ppb) of atrazine and its degradates. The program is dynamic in nature; because CWS enter and exit the program on an ongoing basis, the number of systems that have taken part in this program varies from year to year. The agency may release CWS from the program when those systems have had no exceedances of the level of concern after five consecutive years of monitoring. Conversely, we add CWS into the program based on data gathered under the Safe Drinking Water Act (SDWA) that suggest those particular systems may approach levels of concern.
The data available for this program are the following:
- A summary of data submitted by the registrant from 2003 – 2007
- The complete raw data from the program are available in two locations:
- OPP’s public docket EPA-HQ-OPP-2003-0367
- In the data files listed below
The following data complement the summary listed above. These spreadsheets present atrazine drinking water monitoring data that are required under the 2003 Atrazine Reregistration Eligibility Decision (RED) and subsequent Memorandum of Agreement (MOA) with the atrazine registrants. These Atrazine Monitoring Program (AMP) data files contain the results of the required sampling, by year, for all CWS that have been monitored over a 9-year period from 2003 to 2011.
- 2003 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2004 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2005 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2006 Atrazine Monitoring Program (AMP) & Simazine Monitoring Program (SMP) Drinking Water Data
- 2007 Atrazine Monitoring Program (AMP), Simazine Monitoring Program (SMP) & Simazine Confirmatory Monitoring Program (SCMP) Drinking Water Data
- 2008 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2008 Simazine Monitoring Program (SMP) Drinking Water Data (includes atrazine data)
- 2009 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2009 Simazine Monitoring Program (SMP) Drinking Water Data
- 2010 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2010 Simazine Monitoring Program (SMP) Drinking Water Data (includes atrazine data)
- 2011 Atrazine Monitoring Program (AMP) Drinking Water Data
- 2011 Simazine Monitoring Program (SMP) Drinking Water Data
Each data file includes a “ReadMe” worksheet that explains the data contained in the file. AMP data for 2003 and 2004 do not contain simazine data. AMP data from the latter half of 2005 onward contain data for all triazine residues, including simazine.
Interpreting the Atrazine Drinking Water Monitoring Data
An EPA level of concern is specific to a particular issue (human health, for example) and an exposure period. For example, a long-term (or chronic) level of exposure would be associated with an exposure over many months or years, while an intermediate level of exposure would be looking at potential health effects over a three-month period. Through the atrazine monitoring programs in place, we can evaluate all these potential exposures.
Atrazine potential risk and how it is evaluated
Change in hormone levels is the most sensitive health effect observed in an extensive battery of atrazine toxicity tests. In other words, if our standard is protective of hormonal effects, it will protect against all other effects that occur at higher levels. Our 2003 risk assessment supporting the re-registration of atrazine incorporates standard safety factors to ensure protection of public health, as well as an additional safety factor to ensure further protection for children.
As a result, our risk assessment includes a 300-fold margin of safety to help ensure that an exposure will not affect hormone levels, and a 1000-fold margin of safety to help protect against long-term or chronic effects. In other words, the exposure that the agency allows is at least 300 to 1000 times more protective than the level where the agency saw no adverse effects in the most sensitive animal species tested. EPA applies these additional safety factors as a precaution to protect the public health of all consumers in the United States.
Based on this risk analysis, we determined that concentrations of atrazine and its degradates in raw water below an average of 37.5 ppb over a 90-day period ensures protection of pregnant women and all others, and concentrations of atrazine in finished water that do not exceed 3 ppb as an annual average protect consumers from longer term chronic effects.
The following paragraphs describe the short-, intermediate-, and long-term exposure levels that we have evaluated and found to be protective of human health.
Short-term exposure - Based on the screening-level assessment conducted for the Atrazine Interim Reregistration Eligibility Decision (IRED) from 2003, one-day concentrations less than the Drinking Water Level of Concern (DWLOC) of 298 ppb do not exceed our level of concern for acute effects. In other words, occasional readings of atrazine that are below 298 ppb in water treated by municipalities do not pose a risk to human health.
Intermediate-term exposure - Our level of concern for drinking water is an intermediate level of exposure where the level is exceeded if, in a 90-day rolling average, the concentration exceeds 37.5 ppb for atrazine and its degradates in raw water. After seven years of monitoring, although some amount of atrazine may be detected in community water systems, none of the CWS in the monitoring program have exceeded the 37.5 ppb level of concern as a 90-day rolling average in raw water. This suggests that the more stringent restrictions and use practices required by the agency in 2003 are working to reduce the amount of atrazine reaching water bodies, thereby protecting public health. If any CWS were to exceed this level twice within a five-year period, we would prohibit atrazine use in the watershed associated with the CWS.
Long-term exposure - Under the Safe Drinking Water Act (SDWA), the atrazine Maximum Contaminant Level (MCL) is intended to prevent longer-term, or chronic, health concerns from occurring even after years of exposure and is calculated against a running average from four quarterly samples. An occasional peak concentration above 3 ppb is, therefore, not cause for concern. Rather, a long-term, consistent value above a yearly average of 3 ppb would be of concern. The MCL is designed to protect all population subgroups.
Background on CWS Monitoring Program
The January 2003 Atrazine Interim Reregistration Eligibility Decision (IRED) (323 pp, 1.87 MB) about PDF) and subsequent Memorandum of Agreement (MOA) (36 pp, 132k, about PDF) between EPA and the atrazine registrants initiated a monitoring program to focus on the most significant human health exposures associated with agricultural and residential uses -- exposures through drinking water. Through the CWS monitoring program, we are ensuring that exposures to atrazine in drinking water do not reach levels that pose a risk to public health. Our regulatory program for atrazine ensures drinking water concentrations are below a level that could potentially cause changes in hormone levels, which is the most sensitive health effect observed in an extensive battery of toxicity tests. Our level of concern ensures protection of children and adults, including women of child-bearing age.
How CWS were Chosen - Of the approximately 50,000 CWS in the United States, 40,000 are served by ground water and 10,000 are served by surface water. Because atrazine levels in surface water tend to be higher than those in ground water, surface water is EPA's focus for this monitoring program. In 2003, we identified 3,600 systems where atrazine was used and monitoring information was available. OPP used Safe Drinking Water Act (SDWA) data to screen CWS nationwide to see which systems might be more likely to have higher seasonal atrazine contamination. An initial group of CWS was identified for more intensive monitoring based upon our review of data submitted voluntarily by the registrant. Under conditions of the Atrazine RED and MOA, we required an intensive drinking water monitoring program in these CWS. This monitoring program began in 2003.Information developed by EPA's Office of Water under the SDWA is continually reviewed to determine whether additional CWS should be monitored more intensively through OPP’s required atrazine monitoring program. Since 2003, a number of CWS have been added to OPP’s monitoring program based on SDWA monitoring data as detections approached or exceeded the Office of Water's Maximum Contaminant Level (MCL) for atrazine as an average of four quarterly samples.
CWS Monitoring - Since 2003, raw and finished water at approximately 150 CWS has been monitored under the atrazine MOA to ensure that levels of atrazine and its chlorinated degradates do not reach the level of concern of 37.5 ppb. Because CWS enter and exit the program on an ongoing basis, the number of systems that have taken part in this program varies from year to year. These CWS have been monitored on a weekly basis during the peak atrazine use season and biweekly during the rest of the year.
Under the MOA, monitoring is conducted for at least five years. Two exceedances in raw water at a CWS in different years over a five-year period will result in prohibition of further atrazine use in the associated watershed. If a CWS does not have exceedances during five consecutive years of monitoring, it may be released from this monitoring program. To date, 119 systems have been released from the program, and no system has had two exceedances. Over 30 CWS have been added to program.
EPA will continue to review monitoring data under the SDWA. If any CWS in the future have detections approaching the MCL, then the intensive monitoring requirements and regulatory oversight of the Pesticide Program will be invoked.
During atrazine’s reregistration in 2003, EPA established a framework for developing an aquatic ecosystem level of concern (LOC) that ensures atrazine concentrations in watersheds will not cause significant changes in aquatic plant community structure, function and productivity, the most sensitive effect of concern. Concentrations of atrazine that affect aquatic plant community structure, function and productivity typically occur at levels lower than those that directly affect fish and aquatic invertebrates. By focusing on aquatic plant community structural and productivity changes, the EPA intends to protect invertebrates, fish, and amphibians from the direct effects of atrazine as well as the effects that atrazine could have on the habitat and food sources of aquatic animals.
To that end, in its October 2003 Atrazine Interim Reregistration Eligibility Decision (IRED) (323 pp, 1.87 MB, about PDF), EPA required atrazine registrants to implement an innovative, intensive ecological watershed monitoring program, as well as a risk mitigation process if atrazine water concentrations exceed the agency's levels of concern for aquatic ecosystems.
Level of Concern Development
When atrazine is applied during the growing season, water bodies receive episodic and highly variable amounts of atrazine runoff from agricultural fields. Since 2003, EPA has been working to develop a level of concern (LOC) that is based on the numerous studies (microcosm and mesocosm studies, which are studies designed to mimic conditions in natural communities and ecosystems) where effects on aquatic plants have been measured at constant atrazine concentrations. This analysis allows the agency to better understand and evaluate the varied concentrations and durations of exposures monitored in natural systems.
To address this fundamental challenge of applying experimental toxicity information to natural systems, the EPA developed a tool called the “Plant Assemblage Toxicity Index” (PATI) to estimate the LOC. The PATI methodology uses single-species plant toxicity data and microcosm/mesocosm studies to discern what atrazine exposure patterns and concentrations can cause adverse effects on aquatic plant communities. We use these data to develop a level of concern, which together with monitoring data can be used to identify watersheds where atrazine levels are too high and need to be mitigated consistent with 2003 IRED and Memorandum of Agreement (MOA) (36 pp, 132 KB, about PDF)signed by the agency and Syngenta.
The Current Aquatic Ecosystem Level of Concern
The EPA is currently estimating the aquatic ecosystem level of concern as approximately 10 parts per billion (ppb) for atrazine over a 60-day period. This estimate was developed using the PATI model described in EPA’s issue paper that we presented to the 2009 SAP, available at www.regulations.gov in docket number EPA-HQ-OPP-2009-0104-0006.
If a watershed shows levels of atrazine above this level of concern in any two years of monitoring, atrazine registrants must initiate watershed-based management activities in concert with state or local watershed programs to reduce atrazine exposure. These remedies will be consistent with the approaches used in the EPA Office of Water's Total Maximum Daily Load (TMDL) program but are enforceable under FIFRA through the 2003 Atrazine IRED and Memorandum of Agreement.
Monitoring Results in Areas of Corn, Sorghum, and Sugarcane Production
With regard to corn and sorghum producing areas, the ecological watershed monitoring program was designed to focus initially on flowing water bodies in the most vulnerable watersheds in the Midwest. Monitoring occurred over a three-year period (2004 through 2006), and certain sites have had additional monitoring conducted from 2007-2011. During the sampling timeframe, 40 watersheds (PDF) (2 pp, 125k, about PDF) were monitored for at least two years. These initial 40 were selected to be representative of watersheds potentially vulnerable to atrazine runoff.
The results of this survey informed the agency’s decision to sample an additional 25 sites (1 pp, 73k, about PDF) across the Midwest in 2010 and 2011. These sites appear to have characteristics similar to the most vulnerable of the original 40 sites and thus were expected to be prone to atrazine runoff resulting in water concentrations that exceed the agency's levels of concern. The 2010 and 2011 monitoring results for these new sites, as well as the existing sites, are available at public docket number EPA-HQ-OPP-2003-0367-0206. 17 of these 25 sites will continue to be monitored.
A pilot atrazine monitoring program in water bodies associated with sugarcane crop production was initiated in 2005. Monitoring began in Louisiana in March 2005 and Florida in December 2005. However, the monitoring effort in Louisiana was delayed in the latter half of 2005 because of Hurricane Katrina.
Monitoring Sites that Exceed the Level of Concern
Two Missouri ecological watershed monitoring sites and one Nebraska site have exceeded the agency’s level of concern based on the draft methodology presented to the 2009 FIFRA SAP. The two Missouri sites are in the South Fabius River and Youngs Creek watersheds. The Nebraska site is in the Big Blue River (Upper Gage).
The atrazine registrant, Syngenta, has collected detailed soil, slope and cropping maps, rainfall measurements, crop rotation patterns, and other information about the sites, and continues monitoring in these watersheds. Syngenta is also conducting watershed stewardship and outreach activities with growers and other stakeholders.
These sites remain a high priority for mitigation, as they have repeatedly exceeded EPA’s level of concern:
- Youngs Creek site exceeded in four out of seven years of monitoring
- The South Fabius River site exceeded in five out of seven years of monitoring
- The Big Blue River (Upper Gage) site exceeded in five out of six years of monitoring
As a result, the agency has been working with atrazine registrants to ensure additional mitigation steps are taken consistent with requirements of the 2003 IRED (323 pp, 1.87 MB, about PDF) and Memorandum of Agreement (36 pp, 132 KB, about PDF).
One Louisiana monitoring site has exceeded the agency’s level of concern based on the draft methodology presented to the 2009 FIFRA SAP. Advice from that SAP meeting is helping us interpret these data to determine whether additional monitoring and/or mitigation is needed.
In June 2012, the EPA presented to the FIFRA SAP the refined methodology that updates the current aquatic ecosystem level of concern. The EPA describes this methodology in more detail in its problem formulation for the ecological risk assessment for atrazine, which is available in SAP docket EPA-HQ-OPP-2012-0230. This docket also contains the software that can be used to evaluate and apply the methodology. Additionally, the EPA’s reviews for the microcosm and mesocosm studies considered in the methodological framework are available in public docket EPA-HQ-OPP-2003-0367.
EPA believes that establishing a level of concern with a fixed atrazine concentration and exposure duration will be more useful for state officials and the general public. Therefore, the EPA has used the software posted in the docket to examine data from several intensive watershed monitoring programs (including those conducted by Heidelberg University, states, the U.S. Department of Agriculture and atrazine registrants) to establish a concentration-equivalent level of concern that effectively discriminates between exposures that exceed LOCpati and those that do not. EPA presented the derivation of this “concentration-equivalent” level of concern to the 2012 SAP.
EPA plans to take the recommendations from this SAP as well as previous SAPs into account as it updates the state of the science for the atrazine registration review beginning in 2013. The 2012 SAP Report is located in docket EPA-HQ-OPP-2012-0230.
Based on the review of available scientific studies, EPA determined in 2000 that atrazine is not likely to cause cancer in humans. This determination was the result of a transparent process that invited public participation, solicited development and submission of the best available scientific data, and allowed preeminent independent scientists to ensure that the agency was using the highest quality data in its regulatory decision-making process. This determination was based on results from the full spectrum of animal test data that the agency requires, as well as numerous research studies on atrazine’s mechanism of action.Since the mid-1990’s, EPA has been co-sponsoring epidemiological studies through the National Cancer Institute (NCI) to evaluate the potential for any association between atrazine exposure, as well as other pesticides, to people and cancer, even though rigorously conducted animal studies show that this result is unlikely. In 2011, updated Agricultural Heath Study (AHS) analyses were published that will inform our risk assessment process.
The EPA identified several epidemiological cancer studies for atrazine. Specifically, the agency received and reviewed the following studies noted by the 2003 FIFRA Scientific Advisory Panel (SAP) as particularly important to this question:
- a report from the National Cancer Institute analyzing previous epidemiological studies of atrazine and non-Hodgkin's lymphoma;
- an epidemiological study of all cancers among atrazine agricultural workers from NCI's Agricultural Health Study (2004), entitled Cancer Incidence Among Pesticide Applicators Exposed to Atrazine in the Agricultural Health Study (PDF) (8 pp, 116k, about PDF); and
- a study conducted for Syngenta of the incidence of prostate cancer in workers at an atrazine manufacturing plant in St. Gabriel, Louisiana.
The EPA also received and reviewed an updated epidemiological study comparing specific cancer types between atrazine-exposed and atrazine non-exposed pesticide applicators from the NCI’s AHS. At EPA’s request, the July 26-29, 2011 SAP provided advice about the tools, approaches and endpoints EPA might use in its assessment of potential cancer and non-cancer human health risks of exposure to atrazine.
The EPA values the SAP’s assessment of the atrazine cancer epidemiology studies published 1985 through 2011. Even though the panel agreed with EPA that the epidemiologic evidence does not strongly suggest a link between atrazine and cancer, the panel did not agree that a lack of strong evidence justifies a conclusion that atrazine is not likely to be a human carcinogen. The panel noted some suggestive epidemiologic findings for specific tumors that warrant additional analyses prior to the EPA's full weight-of-evidence review of the cancer classification for atrazine. Following the EPA's Cancer Assessment Guidelines, the agency will weigh and integrate all of the lines of scientific evidence (e.g., toxicology, metabolism, epidemiology, mode-of-action studies). EPA plans to take the recommendations from this SAP report as well as all previous SAPs into account as it updates the state of the science on the health effects of atrazine. The scientific information will be thoroughly considered in registration review of atrazine, scheduled to begin in 2013.
The EPA concluded in 2007 that atrazine does not adversely affect amphibian gonadal development based on a review of laboratory and field studies, including studies submitted by the registrant and studies published in the scientific literature. On June 12-15, 2012, EPA held a FIFRA Scientific Advisory Panel (SAP) meeting that included a review of atrazine studies with amphibians published in the open literature since 2007. The SAP was asked to comment on whether EPA’s analysis appropriately captures all relevant studies and whether uncertainties are adequately characterized. EPA plans to take the recommendations from this SAP as well as previous SAPs into account as it updates the state of the science for the atrazine registration review beginning in 2013. The 2012 SAP Report is located in docket EPA-HQ-OPP-2012-0230.
In June 2003, after evaluating the available literature on the potential effects of atrazine on amphibian gonadal development, EPA concluded that there was sufficient information to formulate a hypothesis that atrazine exposure can affect amphibian gonadal development; however, there was insufficient information to refute or confirm that hypothesis, mainly because of the limitations of the study designs and uncertainties in the data. The agency’s 2003 White Paper (PDF) (8 pp, 62k, about PDF) carefully evaluated the data from 17 laboratory and field studies, discussed remaining uncertainties in evaluating the potential effects of atrazine on amphibian development, and outlined future studies that could address these uncertainties. The FIFRA SAP reviewed EPA’s White Paper and concluded that the agency’s review was thorough, the conclusions were valid, and the approaches and criteria for new studies were appropriate. The SAP also agreed that additional studies were warranted and that a tiered testing approach was appropriate.
In response to a November 2004 Data Call-In (DCI) Notice from EPA, Syngenta, the principal atrazine registrant, developed a testing protocol for determining the effects of atrazine on amphibian gonadal development, and conducted two studies consistent with the first tier of testing described in the 2003 White Paper and the SAP review. In June 2007, Syngenta submitted to EPA its final report regarding the potential effects of atrazine on gonadal development of amphibians.
To ensure the quality and transparency of its assessment of atrazine’s potential to affect amphibian gonadal development, EPA solicited advice from the SAP at a second public peer review meeting on October 9 - 11, 2007. During this meeting, EPA presented its assessment of 19 laboratory and field studies, including the registrant-submitted studies and additional studies available in the public literature since the 2003 SAP. Of the 19 studies, only the two DCI studies submitted by the registrant incorporated all of the design elements recommended by the agency and the 2003 SAP to address uncertainties identified in the 2003 White Paper.
The 2007 SAP agreed with the agency that, although both DCI studies contained some limitations, the overall design and conduct of the studies reflected a high degree of quality control that allowed them to be used to evaluate whether or not atrazine exposure affects amphibian gonadal development. The 2007 SAP also agreed with the agency that other laboratory and field studies reviewed by the agency did not fully account for experimental and environmental conditions that could influence relevant endpoints.
The SAP Panel concluded at that time that atrazine does not produce consistent, reproducible effects on the gonadal development of amphibians; however, the Panel recommended that EPA continue to be apprised of ongoing research and review any new data. The 2007 SAP's final report and recommendations are available in public docket EPA-HQ-OPP-2007-0498.
Based on the agency’s thorough examination of the 19 studies and the 2007 SAP’s subsequent concurrence with the agency’s assessment of those studies, EPA concluded that atrazine does not adversely affect amphibian gonadal development. EPA is not currently requiring additional testing of atrazine on amphibians. EPA has conducted a comprehensive reevaluation of atrazine’s ecological effects, including data on potential effects on amphibians published in the public literature since 2007. EPA presented this evaluation to the FIFRA SAP during its June 12-15, 2012 meeting. EPA plans to take the recommendations from this SAP as well as previous SAPs into account as it updates the state of the science for the atrazine registration review beginning in 2013. The 2012 SAP Report is located in docket EPA-HQ-OPP-2012-0230.