UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D.C. 20460
OFFICE OF CHEMICAL SAFETY AND POLLUTION PREVENTION

MEMORANDUM
Date: June 2, 2015
SUBJECT: Chlorpyrifos Methyl: Tier I Review ofHuman Incidents for Draft Risk Assessment

PC Code: 059102 Decision No.: 503280 Petition No.: NA Risk Assessment Type: NA TXRNo.:NA MRIDNo.:NA DP Barcode: 0426989 Registration No.: NA Regulatory Action: NA Case No.: NA CAS No.: 5598-13-0 40CFR: NA Ver.Apr.OS FROM: Elizabeth Evans, Environmental Protection Specialist

# ~ Toxicology and Epidemiology Branch

### ~ Health Effects Division (7509P) and Shanna Recore, Industrial Hygienist Toxicology and Epidemiology Branch Health Effects Division (7509P)
THROUGH: David J. Miller, Acting Branch Chie Toxicology and Epidemiology Branc Health Effects Division (7509P)
TO: Danette Drew, Risk Assessor Risk Assessment Branch Health Effects Division (7509P) and Joel Wolf, Chemical Review Manager Risk Management & Implementation Branch 2 Pesticide Re-evaluation Division (7508P) Summary and Conclusions Chlorpyrifos-methyl was previously reviewed in 2009 (M. Hawkins, 11 /24/09, D370451). At the time, there were no incidents reported for chlorpyrifos methyl in IDS from 2002- November 2009. Upon review ofthese incidents, it was concluded that, as there were no incidents reported, there was not a concern that would warrant further investigation at the time Page 1of5The current IDS analysis from January 1, 2010 through May 21, 2015, shows one incident reported involving chlorpyrifos-methyl in Main IDS involving multiple active ingredients and 13 incidents involving multiple active ingredients reported to Aggregate IDS

. There were no single chemical incidents reported to IDS

. The query of SENSOR-Pesticides 1998-2011 identified 9 incidents involving chlorpyrifosmethyl but there have been no reports since 2004

. The Agricultural Health Study (AHS) is also a potential source ofinformation associated with human health effects associated with certain pesticides. Chlorpyrifos-methyl is not included in the AHS , thus no AHS information is available for this chemical.
Detailed Review


### I. ACTION REQUESTED Chlorpyrifos-methyl is being considered under the FQPA-mandated Registration Review program established to review, on a 15 year cycle, pesticides for which a Re-registration Eligibility Decision has been made. One component ofthe Agency ' s Registration Review Program is consideration ofhuman incident data

. In conjunction with a human health risk assessment based on other data sources, such human incident data can assist the Agency in better defining and characterizing the risk ofpesticides/pesticide products. Reports ofadverse 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 or otherwise confirmed

. Typically, causation cannot be determined based on incident data. However, incident information can be an important source offeedback 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

. 

### II.BACKGROUND Chlorpyrifos-methyl is a general use organophosphate insecticide registered for use on stored grain (for protection of stored food, feed oil, and seed grains against injury from stored grain weevils, moths , borers, beetles and mealworms including granary weevil, rice weevil , red flour beetle, confused flour beetle, saw-toothed grain beetle, Indian meal moth, and Angoumois grain moth, lessor grain borers) , seed treatment, grain bin and warehouse.
For this evaluation, both OPP Incident Data System (IDS) and the Centers for Disease Control and Prevention/National Institute for Occupational Safety and Health (CDC/NIOSH) Sentinel Event Notification System for Occupational Risk-Pesticides (SENSOR) databases were consulted for pesticide incident data on the active ingredient chlorpyrifos-methyl (PC Code:
Page 2of5059102). The purpose ofthe database search is to identify potential patterns in the frequency and severity ofthe health effects attributed to chlorpyrifos methyl exposure. 

### III. RESULTS/DISCUSSION a. IDS (Incident Data System) OPP' s 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 has compiled these reports in IDS. IDS contains 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. IDS records incidents in one oftwo modules : Main IDS and Aggregate IDS:

o Main IDS contains incidents resulting in higher severity outcomes and provides more detail with regard to case specific

. This system stores incident data for death, major and moderate incidents, and it includes information 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

.

o Aggregate IDS contains incidents resulting in less severe human incidents (minor, unknown, or no effects outcomes). These are reported by registrants only as counts in what are aggregate summaries

. From January 1, 2010 to May 21 , 2015 , there were no incidents reported to Main IDS involving the single active ingredient, chlorpyrifos-methyl. There was one incident reported to Main IDS , involving multiple active ingredients including chlorpyrifos-methyl and deltamethrin that is classified as moderate severity. This incident involved a 30 year old male who was cleaning a spill ofa one ton container ofwheat seed that had been treated with the product (Registration Number 264-992)

. He used a bucket to pick up the seed and move them to a different container. Approximately 4 hours after contacting the seeds, he began to develop a rash on his neck and chest, shortness ofbreath, and facial swelling. His symptoms persistent until the next and he went to emergency department. He was treated with atropine and his symptom resolved

. From January 1, 2010 to March 18, 2015 , there were 13 incidents reported to Aggregate IDS involving chlorpyrifos-methyl. These incidents were classified as minor severity

. Overall there were few incidents reported to IDS involving chlorpyrifos-methyl. 

### b. SENSOR-Pesticides The SENSOR-Pesticides database covers 12 states from 1998-2011 , although reporting varies from state to state. Cases ofpesticide-related illnesses are ascertained from a variety of sources, including : reports from local Poison Control Centers, state Department ofLabor workers '
Page 3of5compensation claims when reported by physicians, reports from State Departments of Agriculture, and physician reports to state Departments ofHealth. Although both occupational and non-occupational incidents are included in the database, SENSOR focuses on occupational pesticide incidents, and is ofparticular value in providing that information

. A state SENSOR contact specialist attempts to follow-up with cases and obtains medical records to verify symptoms, circumstances surrounding the exposure, severity, and outcome. Using standardized protocol and case definitions derived from poison center reporting, SENSOR coordinators at State Departments ofHealth enter the incident interview description provided by the case, medical report, physician and patient into the SENSOR data system. The SENSOR data system is accessible to participating states and EPA.
A query of SENSOR-Pesticides 1998-2011 identifies a total ofnine cases, stemming from nine events, involving chlorpyrifos-methyl (pc code 059102). Ofthese, seven cases involved the single active ingredient chlorpyrifos-methyl. Four ofthe seven single ai cases involved chlorpyrifos-methyl applications to grain storage facilities (the remaining three cases provide no discemable case information)

. There have been no case reports involving chlorpyrifos-methyl since 2004

. Ofthe seven cases single ai chlorpyrifos-methyl cases, two cases were high in severity, one case was moderate in severity, and four cases were low in severity. In one high severity case, a truck driver was near an application made to a wheat storage facility. He developed neurological symptoms including confusion, headache, and blurred vision, gastrointestinal symptoms and rapid heartbeat. He was transported later that evening by his wife to the local ER. He was given atropine, stabilized, and admitted for two days. The second high severity case appears to have been a residential exposure ; however this case was lost to follow-up and no descriptive case information is provided

. The moderate severity case involved a worker mixing/loading the pesticide at a grain manufacturing facility. Ofthe remaining four low severity cases, two involved grain facility exposures and two provided no case details. Ofthe seven single ai cases: six cases experienced neurological symptoms (chiefly headache) and five cases had gastrointestinal symptoms (nausea and vomiting) , three cases had ocular symptoms, two cases had dermal symptoms, two cases had respiratory symptoms and one case experienced cardiovascular symptoms. Although two cases were high in severity, there is a low frequency ofcases and there have been no case reported to SENSOR-Pesticides since 2004.



### c. Agricultural Health Study (AHS)
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 of 50 different pesticide active ingredients commonly used in agriculture

. Chlorpyrifos-methyl is not included in the AHS

. Page 4of5CONCLUSION Based on the low frequency ofincidents reported to both IDS and SENSOR-Pesticides, there does not appear to be a concern at this time. The Agency will continue to monitor the incident information and ifa concern is triggered, additional analysis will be conducted.

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