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( /J /'4/l1;f 0 {-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 if a 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 ofsevere 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 of disease, 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 of alleged 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, if appropriate, fully

reviewed in the risk assessment phase ofthe process. The AHS includes information on use of 50

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 of exposure from the pesticide, and therefore, if present, these incidents are

listed in a table at the end ofthis report. Additionally, since higher severity incidents are

generally of greater 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

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module 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 if a concern is triggered, additional analysis will be included in the risk

assessment.

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