Atrazine Evaluation 

Conference Call with Technical Registrants 

October 7, 2009 

10:30 – 11:00 a.m. EST 

Conference Call Requested By: EPA Office of Pesticide Programs

Participants: 

 

Office of Pesticide Programs, EPA – Robert McNally, Steven Bradbury, Peter Caulkins, 

Catherine Eiden, and Carol Stangel 

Atrazine Technical Registrants – 

SYNGENTA 

Dan Campbell 

1-336-632-7627 

[Also on the call: Janis McFarland] 

AGAN CHEM MFG, LTD 

MAKHTESHIM-AGAN OF NORTH AMERICA INC 

Jennifer Yentel, (919) 256-9300 

Ephi Gur, (919) 256-9318, ephi@manainc.com 

DREXEL CHEMICAL COMPANY 

Luz G. Chan 

(901) 774-4370 

lchan@drexchem.com 

OXON ITALIA S.P.A. 

SIPCAM AGRO USA, INC 

Joseph W. Burley 

(770) 594-6356 

jburley@sipcamadvan.com 

Meeting Summary: 

EPA discussed with the atrazine technical registrants the Agency’s announcement that it is 

launching a comprehensive new evaluation of the pesticide atrazine based on transparency and 

sound science, including independent scientific peer review by the FIFRA Scientific Advisory 

Panel (SAP). The evaluation will help determine whether a change in EPA’s regulatory position 

on atrazine is appropriate. At the end of this process, the Agency will decide whether to revise 

its current atrazine risk assessment and whether new restrictions are necessary to better protect 

public health. 
2

EPA explained that the Agency will engage the SAP to reevaluate the human health effects of 

atrazine over the coming year, including an informational presentation in November 2009 and 

three meetings with the Panel in February, April and September 2010. The SAP meetings will 

be open to the public. At the conclusion of this evaluation of atrazine’s human health effects, 

EPA will ask the SAP to review atrazine’s potential effects on amphibians and aquatic 

ecosystems. 

 

In addition to conducting this science evaluation, EPA will be exploring better ways to inform 

the public more quickly about results of atrazine drinking water monitoring. Also, EPA briefly 

discussed some potential changes to the 2003 Memorandum of Agreement that would address 

some concerns raised in recent media reports. 

Specifically, concern has been expressed about single day spikes of atrazine in drinking water 

that could present a potential health concern. A one-day level of concern (LOC) of 298 ppb was 

established in the 2003 risk assessment. (Currently, the highest one-day level of atrazine in 

drinking water that EPA is aware of is 89 ppb). EPA would like to modify the Atrazine 

Memorandum of Agreement (MOA) to include the following: 

1) exceedance of the 298 ppb one-day level of concern in raw or finished drinking would 

result in prohibition of atrazine use in the watershed associated with the drinking water 

system. 

2) in a subset of Community Water Systems (CWS) in the current monitoring program, 

during a period of high atrazine use, pilot daily monitoring over a finite period -- maybe a 

month -- to see if higher spikes are occurring that the current monitoring is missing. 

These data might be useful for SAP consideration regarding the monitoring frequency. 

 

Concern also has been expressed about drinking water monitoring data being available to local 

communities in a timely fashion. EPA would like to discuss ways to provide these data to 

interested parties more quickly. 

 

Concern has been expressed about whether EPA's performance standard for drinking water is 

sufficiently protective, since EPA is regulating on an intermediate-term exposure effect. The 

Atrazine MOA currently states that atrazine use is prohibited in the watershed associated with a 

CWS when 2 exceedances of 37.5 ppb as a 90 day rolling average in raw drinking water have 

occurred in that CWS. Rather than prohibiting atrazine use in the watershed after 2 exceedances 

in a 5 year period, EPA would like to modify this provision to prohibit atrazine use in the 

watershed after one exceedance in a 5 year period. (There has not been any exceedance of 37.5 

ppb as a 90 day rolling average since the monitoring program was established in 2003). 

EPA will schedule follow-up meetings with the technical registrants in the near future to 

continue this discussion of potential changes to the MOA. 

Meeting Summary Prepared by: Robert McNally