OPP Report on Incident 

Information: The Baseline
OPP Report on Incident Information: The Baseline

Table of Contents 

Introduction ..................................................................................................................... 1 

Section 1:  Overview of Incident Data ............................................................................. 3

What is a pesticide incident?...............................................................................................3 

How is Incident Data Collected?.........................................................................................3 

Table 1.1 – Summary of Incident Data Sources............................................................4 

Profiles of Incident Data Sources........................................................................................5 

Incident Data System (IDS) .............................................................................................5 

Sentinel Event Notification System for Occupational Risk (SENSOR) .......................5 

California Pesticide Illness Surveillance Program (PISP).............................................6 

Poison Control Centers National Poison Data System (NPDS)...................................6 

National Pesticide Information Center (NPIC) ...............................................................7 

Ecological Incident Information System (EIIS)...............................................................7 

National Wildlife Health Center (NWHC) Quarterly Mortality Reports.........................7 

The Avian Incident Monitoring System (AIMS)..............................................................8 

Data Source Practical Considerations................................................................................8 

Table 1.2: Key Features of Incident Data Sources.......................................................9 

Section 2:  How OPP Uses Incident Data ..................................................................... 11

Risk Reduction through Risk Assessment and Risk Management................................11 

Figure 1 – EPA’s Pesticide Regulatory System...........................................................12 

Figure 2:  The Risk Assessment – Risk Management Paradigm ..............................13 

Table 2.1:  Selected Cases Where Incident Data Informed Regulatory Action........14 

Risk Communication ..........................................................................................................14 

Performance Accountability...............................................................................................15 

Enforcement........................................................................................................................16 

Limitations of Incident Data ...............................................................................................16 

Section 3: What Does Incident Data Tell Us? .............................................................. 18

Conclusion .................................................................................................................... 19

2
OPP REPORT ON INCIDENT INFORMATION: 

THE BASELINE

Introduction

The U.S. Environmental Protection Agency’s (EPA) Office of Pesticide Programs’ (OPP)

mission is to protect human health and the environment from unreasonable effects of 

pesticide use.  This responsibility applies not only to the review and licensing of 

pesticides prior to their marketing in the U.S., but to stewardship of existing pesticides 

and pesticide products. 

Prior to registering a pesticide, OPP conducts human health and environmental risk 

assessments to determine the conditions under which a pesticide can be used without 

resulting in adverse effects.  These conditions are reflected in the pesticide’s label.  In

conducting these assessments, OPP may require upwards of 100 studies in areas such

as acute and chronic toxicity, developmental toxicity, and pesticide mobility and 

persistence. 

Similarly, when reviewing an existing pesticide OPP has the ability to require data to fill 

in any gaps in existing knowledge.  The Office has nearly completed its reregistration

process, a major review of existing pesticides and their tolerances (maximum legal 

amounts of the pesticide allowed to remain on food and feed). Reregistration is being

replaced with a process called Registration Review, which will entail the periodic review 

of all pesticides to ensure that their registrations continue to meet current scientific 

standards. 

OPP’s statutory authority requires the Office to consider the benefits of pesticides as 

well as the potential risks.  This does not override the responsibility to protect human

health and the environment but means that where a pesticide’s use provides benefits, 

OPP considers means to ensure that the risk is acceptable.  For human health

concerns, this may take the form of restrictions on the time or amount of application or

the use of personal protective equipment when applying the pesticide.  For

environmental concerns, OPP may place restrictions on where a pesticide can be

applied (e.g., away from water bodies) or how application may occur (e.g., no aerial 

application). 

In reaching regulatory decisions on new or existing pesticides, OPP uses a “line of

evidence” approach, considering all available data to ensure that decisions are both

protective and sensible.  Animal test data are used to characterize what the hazard of a 

pesticide may be, or what risks are associated with its normal use, and to estimate 

exposure levels above which those hazards may occur.  To supplement testing data, 

OPP reviews available field data. These data may be formal monitoring to determine a 

pesticide’s effects on the environment, or may consist of human or ecological incident 

data collected from governmental and non­governmental sources, reported by medical 

professionals, or submitted by pesticide registrants.
In 2006, OPP committed to developing a series of reports on incident information.  In 

this, the first of those reports, the focus is providing an overview of the main sources of 

incident information currently used by OPP.  To understand incident numbers, it is 

important to understand the data sources that provide those numbers.  The report is 

divided into five sections.  Following this first, introductory, section the remainder of the 

report is structured as follows: 

Section 1 ­ Overview of Incident Data. 

This section contains basic information on questions regarding what constitutes a

pesticide incident and how OPP collects incident data.  This section summarizes and

profiles pesticide incident data sources, and discusses practical considerations 

associated with those sources 

Section 2 – How OPP Uses Incident Data. 

This section discusses how incident data is considered in OPP’s regulatory process, 

including risk assessment and risk management, risk communication, performance 

accountability, and enforcement.  There is also discussion of the limitations of pesticide

incident data. 

Section 3 – What Does Incident  Data Tell Us? 

This section provides insight on the difficulty in using incident data to reach conclusions 

on pesticide exposures, and how OPP deals with that issue. 

Conclusion

2 
Section 1: Overview of Incident Data

What is a pesticide incident?

Pesticides are used in a variety of settings every day.  Bug sprays are used in gardens 

and homes, bait traps are put out to control mice, disinfectants insure that surgical tools 

are safe to use, herbicides are applied to corn to control grasses and weeds, and 

kitchen countertops are wiped down using sprays containing antimicrobials.  With this 

amount of use, it is not surprising that there are incidents associated with pesticide use. 

What exactly is a pesticide incident? A simple way to define it is that an incident is any 

effect of a pesticide’s use that is not expected or intended.  For relatively rare incidents 

adversely affecting humans, such as spills, leaks, pesticide movement off­site, or

chronic exposure to sensitive people or those with pre­existing diseases, symptoms 

may include head aches, nausea, a breathing problem, or more severe symptoms.  In 

extreme situations, systematic effects, serious illness, or death may occur.  For an

incident affecting the environment, impacts may include fish or bird kills or damage to 

plants.  In addition, incidents may occur to domestic animals or wildlife. Incidents may 

be occupational, residential, or ecological.

How is Incident Data Collected?

Sources of incident data are as varied as the type of incidents.  Under OPP’s primary 

statute, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), once a 

pesticide is registered a registrant is required to notify EPA if it becomes aware of 

“factual information regarding unreasonable adverse effects on the environment of the 

pesticide”.  In addition, the Agency obtains reports of pesticide incidents from private

citizens, poison control centers, states, and other government and non­governmental 

organizations.

OPP utilizes a variety of incident data sources since no one source completely 

addresses the program’s data needs.   OPP takes a two­pronged approach to incident 

data:  (1) utilize all available incident information to the extent possible, recognizing the

strengths, weaknesses and limitations associated with each data source; and (2) work 

to improve incident information used for decision­making.  Table 2.1 lists OPP’s primary 

sources of incident data, and includes information on the baseline year (how long the

data source has collected data), as well as the source and scope of data collected. 

In addition to the sources listed in Table 2.1, OPP: conducts open literature searches on

case reports and relevant pesticide epidemiology studies; reviews periodic surveys and

studies, such as the National Agricultural Workers Survey, the Washington State

Human Bio­Medical Monitoring Studies on Pesticide Handlers, and the National Cancer

Institute­led interagency Agricultural Health Study (AHS).  Finally, OPP draws upon

continuous bio­monitoring studies of pesticides from all routes of exposure in the 

National Health and Nutrition Examination Survey (NHANES).

3 
Table 1.1 – Summary of Incident Data Sources

Name  Baseline Year Source of Data Scope 

Data Sources with both Human and Ecological Incident Data 

Incident Data

System (IDS)

1992, but 

includes 

earlier

incidents 

Registrants (under FIFRA §6(a)(2), 

general public, and governments; 

international incident reports 

All types – 

occupational, 

residential, 

ecological 

Data Sources with Human Incident Data

National Poison

Data System

(NPDS)

1983; later

expanded to

cover 100% of 

U.S. 

population

Primarily public reporting, through 

Poison Control Centers 

All types 

(national in 

scope)

National 

Pesticide

Information

Center (NPIC)

1978 Predominantly public reporting, 

with some physician reports 

All types 

(national in 

scope)

Sentinel Event

Notification 

System for

Occupational 

Risk (SENSOR)

1998 State coordinators receive reports 

from physicians, emergency room

records, workers’ compensation

claims, Poison Control Centers, 

State Ag. Depts. 

Occupational 

and nonoccupational 

Cal. Pesticide

Illness 

Surveillance 

Program (PISP)

Standard 

collections 

from 1982;

updated 1992

Physicians reported medical 

records, or through review of

worker compensation reports 

Occupational 

and residential 

pesticide 

incidents 

(California 

only)

Data Sources with Ecological Incident Data 

Ecological 

Incident 

Information

System (EIIS) 

~ 1970  Registrants, public literature, public 

news reports, voluntary reports 

from a few states 

Ecological 

Avian Incident 

Monitoring 

System (AIMS)

~ 1970  EIIS, Fish & Wildlife Service 

enforcement cases, some state

reporting, reports from wildlife 

rehabilitation centers 

Ecological 

(incidents 

related to 

birds)

U.S.G.S. Nat’l 

Wildlife Health

Cent. Mortality 

Reports 

1995 Wildlife mortality reports gathered

quarterly by field teams 

Ecological (all 

wildlife –

national in 

scope)

4 
Profiles of Incident Data Sources

When considering a data source it is important to understand its purpose.  The following

are thumbnail sketches of each data source.  In addition to divergent purposes, data 

sources differ in key definitions and in how data are obtained and maintained. 

Understanding these differences is critical to understanding what the data represent and 

the strengths and limitations of those data for OPP purposes. 

Incident Data System (IDS)

IDS is maintained by OPP and incorporates data submitted by registrants under FIFRA

section 6(a)(2), as well as other incidents reported directly to EPA.  FIFRA allows the 

aggregation of individual events in some circumstances.  IDS includes information on 

incidents involving humans, plants, wild and domestic animals where there is a claim of

an adverse effect, as well as detects of pesticides in water.  The vast majority of reports 

are received in paper format. IDS entries act as a pointer to copies of original reports, 

retained on microfilm and scanned images in OPP’s Information Service Center.  Many 

companies use standardized, industry­developed Voluntary Incident Reporting Forms. 

While IDS reports are broad in scope, the system does not consistently capture detailed

information about incident events, such as occupational exposure circumstances or

medical outcome. In most cases data going into IDS is not validated or verified, though

some reports are collected from calls to contract poison control centers. 

Strengths – Centralized system; data “owned” by OPP

Limitations – low to uneven levels of detail, lack of fully automated system ­ difficulty of 

working with data (need to review hard copies instead of electronic searches)

Sentinel Event Notification System for Occupational Risk (SENSOR)

The Centers for Disease Control and Prevention/National Institute for Occupational 

Safety and Health, with some funding from EPA for pesticide poisoning surveillance, 

maintain the SENSOR database which covers all occupational injuries. In part via 

competitive funding to states, SENSOR is used to monitor trends in occupational health 

related to acute exposures to pesticides, to identify emerging pesticide problems, and to

build and maintain state surveillance capacity. SENSOR is a state­based surveillance 

system, with most poisoning incident cases collected from Department of Labor

workers’ compensation claims when reported by physicians, reports from State

Departments of Agriculture, or from poison control centers.  Depending on state 

reporting laws, cases may also come from State Departments of Health based on 

reports by physicians suspecting pesticide exposure.  A state SENSOR contact 

specialist does follow­up with workers 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 of Health enter the incident interview description

provided by the worker, medical report, physician and patient into the SENSOR data 

system, accessible to participating states and EPA.

5 
Strengths – Most comprehensive system for occupational incidents 

Limitations – Only 12 states participate, and a large % of data comes from California 

and Washington State

California Pesticide Illness Surveillance Program (PISP)

The State of California maintains the PISP database and shares data with EPA on

request.  Pesticide­related illness and injury data from PISP are used to validate the

effectiveness of California’s Department of Pesticide Regulation exposure control 

measures and identify potential areas for improvements to state regulations.  Physicians 

must report suspected cases of pesticide exposure in order to be paid in worker

compensation cases and worker’s compensation claims are reviewed and entered into 

PISP.  County agricultural commissioners are notified to follow­up with investigations.

Strengths – Unique infrastructure for follow­up; strong baseline information; longest 

history of record keeping for tends; and, all types of pesticides are included

Limitations – Limited to California; occasional lag time between incident and report 

Poison Control Centers National Poison Data System (NPDS)

NPDS, formerly the Toxic Effects Surveillance System (TESS), is maintained by the

American Association of Poison Control Centers (PCC), with funding from several 

federal agencies.  NPDS is a computerized information system with geographically 

specific and near real­time reporting (for bioterrorism detection purposes).  While the 

main mission of Poison Control Centers is helping callers respond to emergencies, and

not collecting specifics on incidents, NPDS data helps identify emerging problems in 

chemical product safety.  Hotlines at 61 PCC’s nationwide are open 24/7, 365 days a 

year with many bilingual centers in high Spanish speaking areas, and 80 language 

translation capability.  Hotlines are staffed by specially trained nurses to provide

poisoning information and clinical care recommendations to callers with a focus on

triage to give patients appropriate care. Using computer assisted data entry, 

standardized protocols, and strict data entry criteria, local callers report incidents that 

are retained locally and updated in summary form to the national database. Since 2000 

nearly all calls in the system are submitted in a computer­assisted interview format by 

the 61 certified Poison Control Centers, adhering to clinical criteria designed to provide 

a consistent approach to evaluating and managing pesticide and drug related adverse 

incidents.  Information calls are tallied separately and not counted as incidents. The

PCC system covers nearly all the US and its territories and is undergoing major

computer enhancements post 9/11. 

Strengths – National in scope 

Limitations – System is clinically oriented and large (with over 1.5 million records) and

primarily represents residential settings (not currently designed to collect detailed

occupational incident data).  A recent pilot in Colorado is addressing this gap and

could prove to be a National example of improved reporting.  It is difficult to 

interpret trends in PCC data without statistical know how.

6 
National Pesticide Information Center (NPIC)

NPIC is funded by EPA to serve as a source of objective, science­based pesticide 

information in response to inquiries and to respond to incidents. NPIC functions 

nationally during weekday business hours, under a cooperative effort between Oregon

State University and EPA.  Similar to Poison Control Centers, NPIC’s primary purpose 

is to provide information and not to collect incident data.  NPIC does collect information

about incidents from inquirers and reports that information to EPA.  The Center’s main 

role is to provide information to inquirers on a wide range of pesticide topics, and direct 

callers for pesticide incident investigation and emergency treatment. 

Strengths – National in scope 

Limitations – System not designed to collect detailed occupational incident data; limited

# of calls.  Although the main objective is not to obtain incident data, NPIC’s 

recording of calls is guided by Standard Operating Procedures and the ability to

retrieve and use data for such cases is adequate, and has proven useful.  About

10% of NPIC’s annual calls are considered “incident” related. 

Ecological Incident Information System (EIIS)

EIIS is an OPP database with 89 distinct fields within 13 data tables and provides more 

detailed information on IDS incidents involving effects to wild non­target animals and 

plants.  When available, EIIS includes date and location of incident, type and magnitude 

of effects observed in various species, use(s) of pesticides known or suspected of 

contributing to the incident, and results of any chemical residue and cholinesterase

activity analyses conducted during incident investigation. EIIS incidents are categorized

according to the certainty that the incident resulted from pesticide exposure.

Strengths – Detailed information related to ecological impacts 

Limitations – Limited number of reported incidents; difficult to prove cause of mortalities 

National Wildlife Health Center (NWHC) Quarterly Mortality Reports 

The U.S. Geological Survey’s National Wildlife Health Center (NWHC) produces 

quarterly mortality reports detailing wildlife mortality events throughout the U.S. These 

reports are compiled from a database of wildlife mortality events maintained at NWHC. 

Data are gathered by Field Investigations Team personnel collaborating across the 

country, at the federal, state and local levels. Information is most complete post­1975,

but some data are available from earlier years. 

Strengths – Data collected by field personnel, so it is reliable; national in scope

Limitations – Low level of detail; no determination of probability that pesticide caused 

effect; difficult to locate carcasses.  Data is primarily limited to effects on 

migratory birds and endangered species.

7 
The Avian Incident Monitoring System (AIMS)

The Avian Incident Monitoring System (AIMS) was created by a cooperative program

between the American Bird Conservancy (ABC) and EPA, and is now maintained by 

ABC alone. Through AIMS, ABC seeks to collect, store, and report data on pesticide 

poisoned birds, and improve identification, investigation, and laboratory analysis related 

to bird poisonings.  The AIMS database serves as a centralized public source for field 

data on lethal and sub­lethal effects of pesticides on birds. These data can be used to 

develop pesticide usage recommendations, while providing a means to identify risks 

posed by current usage recommendations and label instructions. AIMS facilitates more 

systematic identification, diagnosis, and reporting of pesticide­related bird incidents, and

enables better sharing of information on incidents among government agencies. 

Strengths – High level of detail; data is reliable; national in scope 

Limitations – Small number of cases that are not available from other sources; only 

contains avian incidents

Data Source Practical Considerations

Each data source has strengths and weaknesses, particularly as it relates to OPP’s 

needs.  The next section (How OPP Uses Incident Data) contains a more detailed

discussion of those issues and how they are addressed by the program.  Several 

considerations must be taken into account in deciding whether to routinely use a data 

source, including completeness of data, accessibility, and ability to search the database. 

In addition, as mentioned in the thumbnail sketches of Poison Control Centers and 

NPIC, many of the incident data sources were developed as public health surveillance 

tools to observe trends in health or environmental concerns and not for arriving at point 

estimates of pesticide incidents.

Table 1.2 reviews some of the key features for each data source.  These features 

provide a context for how useful the information provided may be to OPP.  For example, 

the level of detail provided by SENSOR and PISP, which are primarily designed to 

collect data on pesticide incidents, differs from NPIC whose primary purpose is to assist 

the public in obtaining information about pesticides and pesticide exposure.  Table 1.2 

also indicates the volume of reports generated by each data source.  While this may 

vary from year to year, this information allows a comparison between data sources. 

Finally, Table 1.2 indicated the relative cost for each data source.  This cost is not the 

total cost for operating the data source, but rather the cost to OPP.  Where OPP staff 

time is required (IDS and EIIS) this figure is indicated as well.  It should be noted that 

the costs listed for both IDS and NPIC are for all incident data collected, not just human

incident data.

8 
Table 1.2: Key Features of Incident Data Sources

Name  Key Features  # Reports/Yr. Cost/Yr. 

Data Sources with both Human and Ecological Incident Data

IDS • Mainly industry generated, many using

standardized, voluntary format

• Most reports on paper, indexed electronically by 

EPA registration number/incident case number

• Two­tiered search capability (tabular summary 

of ecological and minor human incidents, full 

summaries of moderate/major human incidents)

• Database contains the summaries, but full 

reports are available

• Database is fully searchable by experts 

~ 60,000,

aggregated

from all 

reports 

~$200 K (2 

staff)

Data Sources with Human Incident Data

NPDS

(formerly 

TESS)

• Open 24 hours/day, 365 days a year

• Bilingual in Spanish speaking areas, instant 

access to 80 other languages

• Specialized nurses supported by toxicologists

• Computer assisted data entry using 

standardized protocols and data entry criteria

• Searchable by experts w/ database knowledge 

89,361 (05), 

90,341 (06)

~$45 K 

NPIC • Toll­free service that provides a variety of

information about pesticides

• Information provided includes pesticide product 

information, toxicology, recognition and 

management of pesticide poisonings, safety 

practices, clean up and disposal

• Staffed by pesticide specialists with toxicology 

and environmental chemistry training

• Operates daily from 6:30 – 4:30 Pacific Time 

3,190 (05) ~ $1.6 M

(total cost

for NPIC 

operation,

not just cost 

associated 

with the 

reporting of

incidents)

SENSOR • Fully computerized w/ common case definitions

• Data owned by participating states (12 currently)

• Capacity to identify new hazards/provide rapid 

state follow­up and inter­state communication

• Fully searchable by knowledgeable experts 

~1,000 (@ 1⁄2

of which are 

occupational 

~$350 K

PISP • History of cooperation with EPA

• Product specific use/usage info. by county

• Computerized link to workman’s compensation 

claims data/requirement for physicians report 

prior to payment of workman’s comp claim

~1,000  None

9 
Name  Key Features  # Reports/Yr.  Cost/Yr. 

Data Sources with Ecological Incident Data 

EIIS  Ranges from

~150 to ~675 

~150 K; (1 

staff)

AIMS Rangers from

~40 to ~225

None

NWHC 

Mortality 

Reports 

~ 6­7  None

10 
Section 2: How OPP Uses Incident Data

Section 1 provided an overview of available sources for incident data, and provided 

some insight as to the strengths and limitations of each.  This section will discuss the

ways in which OPP utilizes incident data.  As was discussed earlier, no single data 

source provides perfect data for OPP’s purposes.  In addition, as will be discussed in 

this section, some incident data has severe limitations and must be properly considered. 

While incident data may help provide perspective, it may not be of sufficient quality or

quantity to be appropriate for use in risk assessments for every chemical.  OPP’s 

approach is to utilize all available data, accounting for both strengths and limitations. 

There are several ways in which incident data may help inform OPP’s pesticide 

regulatory process.  For example, incident data may be:

• considered when reviewing applications for registration of new pesticides that are 

chemically similar to existing pesticides;

• used as an indicator of relative risk or unusual exposure situations during 

deliberations on risk management decisions;

• reviewed to determine trends that may indicate potential problems with an existing

pesticide and to track improvements when mitigation measures are applied. 

OPP uses incident information for four primary purposes.  First, incident data is used to

inform risk reduction through risk assessment/risk management activities.  For example,

incident information can indicate a need for new risk management measures and can

help assess the success of risk mitigation actions after they are implemented. Second, 

incident data may be used in risk communication to portray nature, extent and severity 

of incidents to decision­makers, stakeholders and the public in general.  Thirdly, incident 

information is an integral part of OPP’s performance accountability system.  Last, but 

not least, incident information can be useful in targeting enforcement activities and can 

serve as a source for information on compliance with incident reporting regulations.

Risk Reduction through Risk Assessment and Risk Management

The pesticide regulatory system can be seen as an integrated program designed to 

ensure that decisions on pesticide products are translated to actual protections in the

field (Figure 1).  The first step is an assessment of a pesticide’s risks, using a battery of

scientific studies and exposure models.  Second, EPA conducts risk management 

where measures are introduced where needed to allow for the safe use of a pesticide.

Third, risk management decisions are conveyed through label directions so that 

potential risks may be mitigated at the point of use.  Lastly, effective risk communication 

ensures that individuals who use pesticides have the knowledge to use them properly. 

Incident data can help strengthen the links in this integrated program both by helping

OPP make better decisions in addressing potential pesticide risks and by responding to

situations where the goal of safe and beneficial use is being compromised.  This 

feedback is important in ensuring that regulatory decisions are sufficiently protective.

11 
determine

Figure 1 – EPA’s Pesticide Regulatory System

Risk

Assessment

Risk

Management

Risk

Mitigation

Pesticide 

Use

Risk Reduction Through Integrated Protection

Incident data 

may inform 

decisions 

where a new

pesticide is 

similar to an

existing one 

Incident data 

indicate 

relative risk or 

unusual

exposure 

situations 

Incident data 

can help 

indicate areas

where risk 

mitigation is 

necessary 

Incident data 

provides an 

indication of 

whether risk 

decisions are 

effective in 

actual use

Potential 

Pesticide 

Risk 

Actual 

Pesticide 

Risk

EPA’s risk assessment ­ risk management paradigm (Figure 2) helps illustrate how OPP

utilizes incident data.  The paradigm includes four basic risk assessment elements: 

hazard identification, dose­response assessment, exposure assessment, and risk 

characterization.  Data used in hazard identification, dose­response, and some 

exposure assessments are based on laboratory data or data generated by models. 

Incident data can be useful for confirming real world risks that are predicted by “labgenerated” toxicity and exposure data modeling.  For example, an incident of mortality 

of fish in a pond following exposure to an insecticide would confirm a prediction of high 

risk based on laboratory toxicity data and exposure modeling.  In addition to confirming

predicted risks, incident data may show an effect not evident in toxicity tests or help 

OPP compare the risks of a specific pesticide with other products approved for the 

same use. 

Once a risk assessment is completed, it is used to make risk management decisions on 

a product­by­product basis, if product specific information Is consistently captured, as in 

many IDS and NPDS incidents.  If the risks are considered too high, risk management 

techniques can be employed to reduce exposure or the hazard from the pesticide in 

order to reduce the risk.  Many of these techniques are implemented through the 

product’s label.  Examples of risk management techniques utilized by OPP include, but 

are not limited to:

• Restrictions on who can use the product and when and how it can be used;

• Changing product formulation;

• Changing Restricted Entry Intervals (REIs) for workers;

• Reducing application rates;

• Using spray drift control technology;

• Increasing personal protective equipment (PPE);

• Adding engineering controls (e.g., water soluble bags or closed mixing/loading 

systems);

12 
• Canceling uses;

• Setting buffer zones;

• Training for those using the pesticide to ensure proper usage. 

As this figure indicates, incident data may help inform OPP’s activities in any of these 

areas.  While incidents, and incident data, are not generally a determining factor, on

occasion they do indicate trends or areas that need greater attention.

Figure 2: The Risk Assessment – Risk Management Paradigm

Risk 

Characterization

Dose­Response 

Assessment 

Hazard Identification

Exposure 

Assessment 

Regulatory 

Decision

Control Options 

Non­Risk 

Analyses

RISK ASSESSMENT RISK MANAGEMENT

In addition to the product­by­product decisions, OPP utilizes incident data as an aid to 

assess risks and decide on appropriate risk management techniques during rulemaking. 

For example, in drafting worker protection regulations, OPP considered all available 

incident information. 

The risk assessment and risk management process provides the means and

methodology to ensure that pesticides can be used safely, and that public health and

the environment are protected from any unreasonable adverse effects of that use. The

ability to determine details concerning pesticide exposure is critical in developing 

protective risk management strategies.  Analyzing pesticide incident data can provide

an important feedback mechanism.  Specifically, human health incident data can target

13
field program direction and focus outreach and training to reduce pesticide exposures 

and provide impetus to pursue regulatory change. Similarly, ecological incidents 

involving a pesticide may confirm a risk that was predicted by effect and exposure 

models, or it may indicate that the actual risk is greater than that predicted by the 

model. 

On occasion, incident data has been of enough concern for EPA to initiate action

against a pesticide.  Residential use restrictions were applied to both diazinon and 

chlopyriphos, action was taken to control drift for methyl bromide, better packaging was 

required for malathion, and personal protective equipment was required for thiram. 

Some additional cases are outlined in Table 3.1.

Table 2.1: Selected Cases Where Incident Data Informed Regulatory Action

Pesticide  Incidents of Concern  Agency Action Result 

Mevinphos  Worker exposure  Initiated process 

to cancel all uses 

Registrant voluntarily 

cancelled all uses 

Carbofuran Bird kills  EPA responded 

to incidents 

associated with

use of granular

formulations 

Granular formulation

use severely reduced

by elimination of uses 

and limits on amount

allowed for sale

Allercare (trade 

name) selected 

products 

Residential exposure 

(asthmatic reactions,

respiratory problems)

Request for

registrant to 

cancel/recall 

products 

Registrant stopped 

sale and recalled

existing products

Risk Communication

In addition to risk assessment and risk management, incident information can be useful 

in risk communication.  Information on the nature, extent, and severity of incidents is 

valuable in communicating with Congress, the Office of Management and Budget, the 

general public, and stakeholders.  Incident information can provide insight on the

magnitude of problems identified which provides critical information to managers 

involved in resource allocation.  Several OPP public communication efforts have been 

initiated to directly respond to situations where incidents have occurred, including:

• “Lock it Up” – To raise awareness of how to prevent poisonings and exposure to 

household cleaners and pesticides, EPA produced posters encouraging parents to

safely store pesticides – poster displayed on several mass transit systems;

• “Ten Tips to Protect Children from Pesticide and Lead Poisoning” – brochure 

produced in English/Spanish, providing steps to limit pesticide exposure to children;

• “Read the Label First” – community action kit, containing training materials for use in 

heightening awareness about pesticide poisonings.  In addition, posters, magnets, 

and bookmarks were produced;

14 
• National Hispanic Outreach Initiative ­ Launched in 2004, focused on reducing risk in 

Latino communities by providing pesticide safety information through mass 

communications ­ TV, radio and press, including segments broadcast nationally on

the three major networks (Univision, Telemundo, CNN en Espanol.  Reached about

63 million Hispanics in the U.S. and 16 million households in Latin America in 2006.

Performance Accountability

Accountability mechanisms, such as performance measures, are important to ensure 

good program management and provide an objective means to determine if a program’s 

intended outcomes are being met.  Incident data help measure the effectiveness of risk 

management actions that OPP has taken to protect human health and the environment. 

For example, in EPA’s 2006 ­2011 Strategic Plan, there are two measures dealing with 

human incidents under Goal 4, Objective 1, Sub­objective 3:

By 2011, improve the health of those who work in or around pesticides by 

reaching a 50% targeted reduction in moderate to severe incidents for 6 acutely 

toxic agricultural pesticides with the highest incident rates:  chlorpyrifos; diazinon; 

malathion; pyrethrins; 2,4­dicholorophenoxyacetic acid (2,4­D); and carbofuran. 

[Baselines established using PCC­TESS (NPDS) data for 1999 – 2003 and 

updates through 2004­2005 with 2006­2007 data expected in early 2008.]

Through 2011, protect those occupationally exposed to pesticides by improving

upon or maintaining a rate of 3.5 incidents per 100,000 potential risk events.

[Baselines established using data from PCC­TESS (NPDS) as of May 2007, and 

EPA’s earlier 1992 Regulatory Impact Analysis for the Worker Protection

Standard and U.S. Department of Labor updates]

The first measure is meant to gauge OPP’s efforts to improve the health of those who

work with or around six acutely toxic pesticides with the highest incident rates. It is 

OPP’s intent to realize a 50% reduction in the number of moderate to severe incidents 

for these six acutely toxic agricultural pesticides by 2011 as a result of the risk 

management decisions that OPP has made and is implementing for these pesticides. 

Reviews of the number of occupational incidents for these six chemicals will help OPP

determine if the risk reduction actions taken in the reregistration process have had the 

intended effect and to take additional action if appropriate. 

While OPP is intent upon reducing the incidents associated with these six pesticides, it 

is also important to monitor all other incidents to make sure that the number of incidents 

overall does not increase.  The first measure listed from the Strategic Plan is intended 

to monitor the rate of occupational incidents to ensure that the established level of 

protection is maintained or improved upon over time.

15
Enforcement

Enforcement data are useful in providing information on incidents that have previously 

been reported and, in some less frequent situations, to identify incident trends.  In the 

first instance, if an incident is the result of a suspected violation of FIFRA, an inspection

may be requested. This inspection can provide additional details concerning the 

incident, including verification of the cause­effect linkage, more information about the

magnitude of the exposure or the resulting adverse effect. 

It is also possible for a series of investigations to point towards incidents that have not 

been previously reported.  For example, an investigation resulting from a complaint

about spray drift may uncover adverse effects that were previously unreported in any 

incident reporting system.  Through collection and review of incident information, OPP

can help EPA’s Office of Enforcement and Compliance Monitoring target inspections 

where there are potential compliance problems, which may lead to breaking the noncompliance/ incident cycle. Improvements to near real­time NPDS pesticide incident 

reporting for bioterrorism control purposes, reduced use of the most risky chemicals, 

and increased emphasis on prevention of a wider range of more subtle health end 

points in an increasingly aging population will make possible a new generation.

Limitations of Incident Data

As discussed in this section, appropriate use of incident data can assist OPP in a 

number of ways.  It is important, however, to note the limitations associated with 

incident data.  This underscores the importance of the lines of evidence approach used

by OPP – where available, incident data is considered along with other data and is 

given the proper consideration. 

So what are some of the problems with incident data as it is currently available?  Some 

of the more notable limitations include: 

Underreporting – There is undoubtedly some degree of underreporting in every incident 

database regularly used by OPP.  This underreporting is the result of a number of

factors including, but not limited to:

• The lack of a universal, mandatory legal duty to report;

• No central reporting point for all incidents;

• No requirement for active monitoring for incidents;

• Symptoms associated with pesticide poisonings are often vague or mimic other

causes leading to incorrect diagnoses;

• Physicians may also misdiagnose due to a lack of familiarity with pesticide effects;

• Incidents are often not investigated adequately enough to identify the pesticide that 

caused the observed effects;

• Difficulty in identifying and tracking chronic effects;

• Reluctance or inability to report;

• Limited geographic coverage for individual databases; and

16 
• For ecological incidents, difficulty in observing carcasses of animals poisoned in the

wild (mortality often occurs under dense vegetation or in sparsely populated areas or

scavengers scatter or devour the carcass before it is discovered). 

It is difficult to determine the magnitude of underreporting.  Clinical follow­up studies in 

several locations have shown that 4­25% of human pesticide poisoning cases are 

reported to poison control centers. OPP recognizes that as a significant issue that may 

only be addressed with significant additional investments that are not currently feasible. 

Double Counting – It might seem as though it would be possible to simply add or

subtract incident numbers from different data sources to determine the total number of

incidents.   This seemingly logical method is actually misleading because the same 

case could be reported in multiple data sources and, in many cases, specific information

recorded in the database is not adequate to determine whether a particular case in one 

database is the same case or merely a similar case in another database. Since data 

sources have different purposes and geographic coverage, it is generally assumed that 

cases are not duplicative, unless conclusively shown to be so by date, place and

particular circumstances of exposure. While it may be possible to make this 

determination routinely for SENSOR, California data, NPDS data, and clinical cases 

reported in the open literature, it is more difficult for IDS and NPIC.  When available, 

NPIC does record name, address, and phone number of the affected individual, the

EPA registration number, name, and active ingredient of the product, and the

circumstances of the incident.

Resources – Collection of incident data, particularly ecological data, takes significant 

resources.  This leads to a limited number of incidents being reported per year, even in 

the best system.  In addition, limited resources at the federal level have hindered OPP’s 

efforts to improve data collection and use and in providing funding for existing incident 

data sources.

Completeness/Usefulness of Data – This is a general category that covers a variety of 

shortcomings with much of the available incident data.  As mentioned earlier, several 

sources of incident data are primarily designed to disseminate information on pesticides 

and not to collect pesticide incident data.  As a result, the data from these sources may 

be lacking in sufficient detail.  In many cases, when an incident is reported useful 

information such as the exact product that was the source of the exposure, the amount 

of pesticide involved, or the circumstances are omitted.  In many cases there is not 

enough information to determine if the adverse effects noted were in fact the result of 

pesticide exposure and not another contributing factor.

17
Section 3: What Does Incident Data Tell Us?

For the reasons listed above, it is very difficult to reach precise conclusions based on

incident data.  For example, estimating how many occupationally­related pesticide

poisoning incidents occur in the United States results in numbers as varied as the data 

sources themselves.  National data from the American Association of Poison Control 

Centers indicates that the answer may be 1000 – 2000 for 90,341 consumer reported

exposures in 2006.  The range reaches between 1500 ­ 6000 if looking at SENSOR 

data on handlers and agricultural workers extrapolated to the entire U,S, 

When the U.S. Department of Labor’s 1999 National Agricultural Workers’ Survey 

(NAWS) asked workers if they had been poisoned by pesticides in the previous year

and 1.4% of the estimated 1.8 million farm workers (or 25,200 workers) said “yes.”

However, the number was 10,000 ­ 40,000 when OPP estimated agricultural worker

poisonings in the 1992 Worker Protection Standard Regulatory Impact Analysis.  As has 

been noted, each estimate has limitations.  For example, OPP’s analysis is hampered

by the inadequacy of national pesticide poisoning surveillance, which has been

criticized on several occasions by the Government Accounting Office.  These 

considerations do not make a particular answer to the “how many?” question wrong or

right, but perhaps more or less useful depending on the intended use for the answer

All of this serves to point out the complexity of determining the number of pesticiderelated incidents, whether they are occupational or residential in nature or whether they 

impact human health or the environment.  Although OPP would prefer to have a precise 

number of incidents in every category of interest, the fact is that the program’s success 

is not dependent upon this precision.  More important than the precision of this number

is an understanding of the magnitude of the problem. 

Along with the magnitude, reliable trend information is also arguably more important 

than greater precision.  For example, assume there were 20 incidents reported last 

year.  Is this number down from 100 five years ago or up from 5 incidents two years 

ago?  These different trends would no doubt lead OPP to different risk management 

decisions. Precisely counting incidents is not OPP’s goal; rather, the ultimate goal is to

minimize the occurrence of incidents.  Every incident avoided furthers OPP’s mission of 

protecting human health and the environment. 

The practical implication is that OPP must perform a balancing act with limited

resources.  OPP must balance the resources spent on gathering and managing incident 

information to increase the precision against the resources needed to prevent or

mitigate potential future incidents. The two performance accountability measures OPP

included in the Strategic Plan reflect this balancing act (see Section 2’s “Performance 

Accountability” section).

18 
Conclusion

OPP is currently considering how best to manage and utilize incident data.  This 

process includes examining internal processes, data sources, and current procedures. 

The program will continue to periodically update its stakeholders on our activities in this 

area.

19