UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, 

### D.C. 20460

OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION



### MEMORANDUM
Date: March 1,2011
SUBJECT: Isoxaflutole: Review ofHuman Incidents
PC Code: 123000 Decision No.: 443439 Petition No.: NA Risk Assessment Type: NA TXRNo.:NA MRIDNo.:NA DP Barcode: D386532 Registration No.: NA Regulatory Action: NA Case No.: NA CAS No.: 141112-29-0 40CFR:NA Ver.Apr.08 

### FROM: Shanna Recore, Industrial Hygienist Toxicology and Epidemiology Branch Health Effect Division (7509P) , 

### h 0_ "'01( 

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### {-IV//~/"-~' THROUGH: David Miller, Acting Branch Chief 

# (ftlt/ ' Chemistry and Exposure Branch Health Effects Division (7509P)
TO: George Kramer, Risk Assessor Risk Assessment Branch I Health Effects Division (7509P) and Dana Friedman, Chemical Review Manager Risk Management & 

### Implementation Branch II Pesticide Re-evaluation Division (7508P)
I. CONCLUSION Based on the low frequency and severity ofincident cases, there does not appear to be a concern at this time that would warrant further investigation. The Agency will continue to monitor the incident information and ifa concern is triggered, additional analysis will be included in the risk assessment.

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### II. ACTION REQUESTED
This review is intended to fulfill our requirement to docket summaries ofincident data that were reported to the Agency, as well as to ensure human incident data, and the Agricultural Health Study (ARS) are part ofthe problem formulation phase ofregistration review

. Reports of adverse health effects allegedly due to a specific pesticide exposure (i.

### e., an "incident") are largely self-reported and therefore, generally speaking, neither exposure to a pesticide or reported symptom (or the connection between the two) is validated. Typically, causation cannot be determined based on incident data. However, incident information can be an important feedback loop to the Agency - incidents of severe outcome, or a suggested pattern or trend among less severe incidents can signal the Agency to further investigate a particular chemical or product. Observational epidemiology studies relate the risk ofdisease, 

### e.g., cancer, and exposure to an agent such as a pesticide product in the general population or specific sub-groups like pesticide applicators.


### III. BACKGROUND
For this evaluation, the OPP Incident Data System (IDS) was utilized for pesticide incident data on the active ingredient isoxaflutole (pC Code 123000). The purpose ofthe database search is to identify potential patterns on the frequency and severity ofthe health effects attributed to isoxaflutole exposure
. The IDS includes reports ofalleged human health incidents from various sources, including mandatory Federal Insecticide , Fungicide and Rodenticide Act (FIFRA) Section 6 (a) (2) reports from registrants, other federal and state health and environmental agencies and individual consumers. Since 1992, OPP compiles these reports in IDS. IDS contain reports from across the U.S

. and most incidents have all relevant product information recorded. Reports submitted to the IDS represent anecdotal reports or allegations only, unless otherwise stated in the report. The AHS is a high quality, prospective epidemiology study evaluating the link between pesticide use and various health outcomes including cancer. The AHS includes private and commercial pesticide applicators and their spouses. Ifthere are AHS findings relevant to a particular pesticide going through registration review, the Agency will ensure they are considered in the problem formulation/scoping phase ofthe process and, ifappropriate, fully reviewed in the risk assessment phase ofthe process
. The AHS includes information on use of50 different pesticide active ingredients commonly used in agriculture.



### IV. RESULTSIDISCUSSION
IDS records incidents resulting in higher severity outcomes in more detail, in a module called the Main IDS module. This system stores incident data for death, major and moderate incidents, and it includes more details about the location, date and nature ofthe incident. Main IDS incidents involving only one pesticide are considered to provide more certain information about the potential effects ofexposure from the pesticide, and therefore, ifpresent, these incidents are listed in a table at the end ofthis report. Additionally, since higher severity incidents are generally ofgreater concern, incidents involving death and major outcomes would also include a narrative summary. The less severe human incidents (minor, unknown, or no effects outcomes) are reported by registrants as counts called aggregate summaries and are recorded in separate

Page 2 of3module called Aggregate IDS. In Aggregate IDS, from January 1,2002 to May 27,2010, there are three cases reported for isoxaflutole. Because it falls within the categories reported as counts (which includes minor, unknown or no effects), there is no unique report that provides details about the incident and single chemical incidents are not distinguished from multiple chemical incidents; however, a high frequency ofincidents indicates there is a high potential for exposure and vice versa. For isoxaflutole, there appears to be a low potential for exposure. For the Main IDS, from January 1,2002 to November 30,2010, there are no cases reported that involve the active ingredient isoxaflutole.
Isoxaflutole is included in AHS, but it is part ofphase III and those data have not been published yet.
Based on the lack ofincident cases reported to IDS, there does not appear to be a concern at this time that would warrant further investigation. The Agency will continue to monitor the incident information and ifa concern is triggered, additional analysis will be included in the risk assessment.

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