Page 2 of 51

to consider in its updated Chlorpyrifos Risk Assessment, and TEB was requested to provide an 

updated Tier II Incident Report. 

The review considers a variety of types and sources of human observational information 

including human incident data, medical data/case report information, and epidemiological 

information in an effort to inform the re-evaluation of chlorpyrifos in this phase of Registration 

Review. The human incident databases that were reviewed are:

OPP Incident Data System (IDS); 

National Pesticide Information Center (NPIC); 

NIOSH’s Sentinel Event Notification System for Occupational Risks (SENSOR); 

California Pesticide Illness Surveillance Program Incident Data (CA PISP). 

Together, these databases indicate that the number of incidents associated with chlorpyrifos 

declined post-2002, correlating well with the phase out/cancellation of the almost all chlorpyrifos 

residential products in December 2001. In addition, the Agency's findings are consistent with 

other incident cases investigations of American Association of Poison Control Centers (AAPCC)

data which have reported a decrease in the number of chlorpyrifos incidents that is temporally 

associated with the phase out/cancellation of most residential chlorpyrifos products. 

While the chlorpyrifos incidents are reported to have declined substantially (95%) among 

residential users from 2002 to 2010, it is unclear if occupational incidents have also decreased.

Specifically, chlorpyrifos occupational incidents, reported in CA PISP and SENSOR databases, 

appear to be constant over time, despite risk mitigation implemented including reduced 

application rates and seasonal maximum limits, increased retreatment intervals, increased PPE 

and/or use of engineering controls which were required as well as increased re-entry intervals 

(REIs) for a number of crops. Overall, the NIOSH SENSOR database indicated that the largest 

number of incidents are exposures due to actual application of chlorpyrifos, but California PISP 

data suggests that drift of chlorpyrifos to adjacent fields appears to be the largest contributor to 

occupational exposure . OPP has reviewed the incidents reported and will continue to monitor 

these incidents and remain alert for any changes in trend or patterns.

In addition to the incident/poisoning data and medical case reports, epidemiological research can 

be an important source for human observational data and can potentially assist in identifying, 

characterizing, and (ideally) quantifying linkages between human exposures and resulting health 

effects. For chlorpyrifos, epidemiological data are available from both the Agricultural Health 

Study (AHS) and from a variety of university-based research groups. While the AHS 

investigations currently published were hypothesis-generating in nature, initial strength and 

consistency in the findings for lung cancer and colorectal cancer are notable, and warrant further

follow-up and additional research. Preliminary associations with breast and prostate cancer are 

weak, but also warrant monitoring the literature for additional publications on this association. 

There is no compelling evidence of an association with other cancer sites including pancreatic 

cancer, melanoma, brain, esophageal, kidney, all lymphohematopoietic cancers combined and 

NHL, leukemia, and multiple myeloma (Christensen, 06/16/2011, D388167). These data alone 
Page 3 of 51

do not provide sufficient evidence to determine whether a causal association exists between 

chlorpyrifos exposure and these anatomical cancer sites. Information derived from animal 

toxicology data will continue to be used to evaluate cancer risk. However, EPA will continue to 

monitor this literature to determine if information provided in human epidemiology studies 

provide additional evidence as to the carcinogenic potential of chlorpyrifos.

Finally, there are a number of ongoing university-based epidemiologic studies that are examining 

the association between pre-natal and early life chlorpyrifos and OP pesticide exposures and 

neurodevelopmental and neurobehavioral effects. EPA has concluded from these studies that the 

observed association between chlorpyrifos and OP pesticide exposures and neurodevelopmental 

and neurobehavioral deficits is compelling, as similar results were obtained across the three 

children’s health cohorts with respect to neurodevelopmental outcomes in neonates and young 

children. Notably, associations between chlorpyrifos and OP pesticides and these 

neurodevelopmental effects were pronounced in the time period prior to the voluntary 

cancellation of the insecticide for the in-home, residential environment, and the links were absent 

in studies conducted subsequent to the removal of chlorpyrifos use from the home pesticide 

market. EPA has concluded, with the input and concurrence of an external peer-review panel 

(FIFRA SAP, September 2008), that chlorpyrifos exposure likely played a role in these adverse 

neurodevelopmental outcomes. (See Appendix C “Epidemiological Research: Health Effects in 

Children,” May 2011)

1. BACKGROUND

Chlorpyrifos (O,O-diethyl O-(3,5,6-trichloro-2-pyridyl) phosphorothioate) is an 

organophosphate insecticide, acaricide and miticide used to control a variety of insects. 

Chlorpyrifos was first registered in 1965 for control of foliage and soil-borne insect pests on a 

variety of food and feed crops. Currently-registered uses include food and feed crops, golf course 

turf, greenhouses, non-structural wood treatments such as utility poles and fence posts, ant bait 

stations, and as an adult mosquitocide.

In June, 2000, the Agency released its revised human health risk assessment and entered into an 

agreement with the technical registrants to voluntarily cancel and phase out certain uses of 

chlorpyrifos. The agreement was established at that time in order to expeditiously address food, 

drinking water, residential and non-residential uses posing the greatest risks to children. An 

Interim Reregistration Eligibility Decision (IRED) was issued in February 2002. The IRED 

included additional mitigation measures addressing occupational and ecological risks not 

addressed in the June, 2000 agreement. Risk mitigation measures include eliminating use on 

tomatoes, restricting use on apples, phasing out termiticide use, canceling all homeowner use 

product registrations (except ant bait stations), and canceling uses in schools and parks where 

children may be exposed. To mitigate worker risks, a combination of reduced application rates 

and seasonal maximum limits, increased retreatment intervals, increased PPE and/or use of 

engineering controls were required as well as increased re-entry intervals (REIs) for a number of 

crops (Drew, 02/09/2009, D361144).
Page 4 of 51

Chlorpyrifos is a pesticide being considered under the Registration Review program established 

in 2006 to review, on a 15 year schedule, pesticides for which a Reregistration Eligibility 

Decision has been made. During the problem formulation phase of Registration Review for 

chlorpyrifos, the EPA Office of Pesticide Program’s (OPP) Incident Data System (IDS) was 

queried to determine whether reported human incidents involving chlorpyrifos might be an 

important source of information to consider during the preliminary risk assessment phase of 

Registration Review for chlorpyrifos. Hawkins and Cordova (2008) found 126 incidents 

reported from January 1, 2002, to March 2008 in IDS. Based on the frequency and the effects 

noted in the IDS-reported human incidents involving chlorpyrifos identified during the problem 

formulation phase of Registration Review) the Agency determined these data are an important 

source of information to consider in its June 2011 risk assessment of Chlorpyrifos and TEB was 

requested to provide an updated Tier II incident report for use in preparation of the June, 2011 

risk assessment. 

It is important to recognize, however, that 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 symptoms (or the connection between the 

two) are validated. Therefore, only rarely can causation be determined or definitively identified 

based on incident data. However, incident information can provide important feedback to the 

Agency. Human incident data, in concert with other human observational information (medical 

case reports, general medical information, biomonitoring and epidemiological studies) and the 

human health risk assessment, can assist the Agency in determining the risk pesticides/pesticide 

products are posing to the U.S population and can help characterize that risk. This review 

assesses human observational information regarding chlorpyrifos to inform the preliminary risk 

assessment phase of Registration Review. 

2. TIER II REVIEW OVERVIEW

Generally, the Agency relies on toxicity studies conducted on animals and exposure information 

relevant to the pesticide’s use pattern when registering a pesticide. However, after a pesticide is 

registered, different types of human observational data about the effects and exposure of 

registered pesticides may be collected, analyzed and published. These are from a variety of 

sources including: 

Human incident (poisoning) data from such sources as OPP’s Incident Data System (IDS) 

database, NIOSH SENSOR, the Agency-sponsored National Pesticide Information 

Center (NPIC), California’s Pesticide Incident Surveillance Program (PISP), and 

summary data from the American Association of Poison Control Centers (AAPCC).

Human toxicological reviews and medical case reports from the literature

Epidemiological studies from the literature

As the Agency reevaluates pesticides during the Registration Review program, these additional 

sources of information are considered. Specifically, this review considers these different types 

and sources of human observational information and is intended to inform the re-evaluation of 

chlorpyrifos in this phase of Registration Review. 
Page 5 of 51

3. HUMAN INCIDENT DATA

As indicated above, incident information can provide important feedback to the Agency, 

assisting in determining actual real-world exposures and risks posed by pesticides/pesticide 

products. Incident data are collected systematically, but differently, across the different 

databases used by the Agency with respect to such issues as coverage, certainty/confidence, 

fields/parameters reported, and usability. The aforementioned five pesticide incident data 

sources (IDS, NIOSH/SENSOR, NPIC, California PISP, and AAPCC) were used in this 

chlorpyrifos report since they provide useful content and historical perspective. Various other 

comparable sources of data are available (e.g. the Bureau of Labor Statistics, emergency room 

outpatient surveillance, National Poison Data System (NPDS), etc.) but are believed to be of 

limited additional utility and were not investigated. By looking across the five data sources 

which were used, the Agency is confident that we are considering adequate and appropriate 

information to discern trends and patterns in chlorpyrifos-associated incident poisonings.

3.1. OPP Incident Data System (IDS)

The OPP 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 and reports from other federal and state health and environmental agencies and 

individual consumers. Since 1992, OPP has compiled these reports in IDS. IDS contain reports 

from across the U.S. and most incidents contained in the system have all relevant product 

information recorded. Case reports or “narratives” are provided for each incident, with varying 

levels of detail; however, there is no effort at validating or assessing how likely it is that the 

reported exposure is causally related to the reported outcome. Because IDS has such extensive 

coverage, it is useful for providing temporal trend information and determining whether risk 

mitigation has helped reduce potential pesticide exposure and decreased the number of potential 

incidents reported to IDS. 

For this evaluation, the OPP IDS was utilized for pesticide incident data on the active ingredient 

chlorpyrifos (PC Code 059101). This database search was done to identify the frequency and 

severity of the health effects attributed to chlorpyrifos exposure as well as potential patterns and 

trends. Reports submitted to the IDS represent anecdotal reports or allegations only, and are not 

necessarily confirmed, validated, or investigated by medical professionals unless otherwise 

stated in the report.

IDS records incidents resulting in higher severity outcomes, in a module called the Main IDS 

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

includes more details about the location, date and nature of the 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 these incidents are reviewed 

individually in this assessment. 

The less severe human incidents (those outcomes reported as “minor”, “unknown”, or “no 

effects”) are reported by registrants as counts called aggregate summaries and are recorded in a 

separate module called Aggregate IDS. In Aggregate IDS, queried from January 1, 2002 to May 

27, 2010, there are 745 incident involving chlorpyrifos. Because it falls within the categories 
Page 6 of 51

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 of incidents indicates there is a high 

potential for exposure and vice versa. For the Main IDS-- which for this report was queried over 

the date range from January 1, 2002 to February 1, 2011 -- there are 247 cases reported that 

involve the active ingredient chlorpyrifos. Of these 247 cases, there are 141 cases reported for 

the single chemical chlorpyrifos in the database. Summaries of these 141 incidents are recorded 

in Appendix A. These incidents were mostly categorized as HCs (Human Moderates); however, 

there is one categorized as HA (fatalities) and 12 categorized as HBs (Human Majors). Fifteen 

of these incidents were reported as affecting children 6 years old or under (2 HBs and 13 HCs). 

These latter incidents appear to be due to accidental ingestion and post application exposure to 

cancelled products. 

Based on the IDS reports, symptoms most often reported were gastrointestinal, dermal, 

neurological, respiratory, and ocular. Note that a patient could exhibit multiple symptoms. 

Gastrointestinal symptoms reported were nausea, vomiting, diarrhea, and abdominal pain. 

Dermal symptoms reported were rash, lesions, hives, burning sensation, irritation, and blisters. 

Neurological symptoms were tremors, headaches, dizziness, confusion, memory dysfunction, 

numbness and tingling sensations, muscle weakness, muscle spasm, and seizures. Respiratory 

symptoms were choking, coughing, shortness of breath, sore throat, and burning sensation in the

throat. Ocular symptoms reported were lacrimation, burning sensation, pain, and itchiness. 

Figure 1 shows the Main IDS-reported chlorpyrifos incidents from 2002 to 2010. These appear 

to have decreased substantially in this period from 43 incidents in 2002, to 2 incidents in 2010. 

The initial large reductions generally coincide with the dates for which regulatory actions were 

taken. 

Figure 1. Main IDS Chlorpyrifos Incident Count (Chlorpyrifos-only A.I.), 2002-2010

0

5

10

15

20

25

30

35

40

45

50

2002 2003 2004 2005 2006 2007 2008 2009 2010

Incident Count

Year
Page 7 of 51

3.2. National Pesticide Information Center (NPIC) 

NPIC is a cooperative effort between Oregon State University and EPA which is funded by EPA 

to serve as a source of objective, science-based pesticide information and respond to inquiries

from the public and to incidents. NPIC functions nationally during weekday business hours

through a toll-free telephone number in addition to the internet (www.npic.orst.edu) and email. 

Similar to Poison Control Centers, NPIC’s primary purpose is not to collect incident data, but 

rather to provide information to inquirers on a wide range of pesticide topics, and direct callers 

for pesticide incident investigation and emergency treatment. Nevertheless NPIC does collect 

information about incidents (approximately 4000 incidents per year) from inquirers and records 

that information in a database. NPIC is a source of national incident information; but generally 

receives fewer reports than IDS. Regardless, if a high frequency is observed in IDS, NPIC 

provides a source of information to see whether we can demonstrate consistency across national 

data sets. 

For NPIC from 2002 to 2010, there are 178 cases reported for chlorpyrifos in the database. Of 

these cases, 88 were reviewed because, in these cases, chlorpyrifos was used as a single chemical 

and had a certainty classification of probable, possible, or unclassified; such classifications

provide more reliable information about the potential effects of chlorpyrifos exposure. Eight of 

the chlorpyrifos cases were associated with children six years old or younger. The health effects 

reported include: neurological, gastrointestinal, respiratory, ocular, dermal, and cardiovascular. 

As shown in Figure 2, chlorpyrifos incidents reported to NPIC appear to be decreasing over time, 

and show similar trends to those described above for IDS. Note that incidents reported in NPIC 

may overlap with incidents reported in other database systems such as those managed by 

AAPCC and EPA’s IDS database. 

Figure 2. NPIC Chlorpyrifos Incident Count, 2002-2010

0

5

10

15

20

25

30

2002 2003 2004 2005 2006 2007 2008 2009 2010

Incident Count

Year
Page 8 of 51

Stone et al. (2009) analyzed OP incident from NPIC's incident database for longitudinal 

trends, including incidents for chlorpyrifos, diazinon, and malathion reported to NPIC. The 

exposure incidents were grouped into pre- (1995-2000) and post-announcement of phase-out 

(2001-2007) periods. They reported that the number of chlorpyrifos incidents decreased over 

time. Similarly, the informational inquiries NPIC received regarding chlorpyrifos declined 

overtime following the phase-out announcement.

Overall, the NPIC data suggest that incidents associated with chlorpyrifos are declining over 

time and in recent years have numbered only a handful each year. This is in general agreement 

with was has been seen in the Agency’s IDS reporting system. 

3.3. NIOSH Sentinel Event Notification System for Occupational Risks (SENSOR)

The NIOSH SENSOR database covers 12 states from 1998-2006, although reporting varies from 

state to state. Pesticide-related incidents are collected from Department of Labor workers’ 

compensation claims when reported by physicians, reports from State Departments of 

Agriculture, from poison control centers and from State Departments of Health based on reports 

by physicians suspecting pesticide exposure. Although both occupational and non-occupational 

incidents are included in the database, SENSOR focuses on occupational pesticide incidents, and 

is of particular value in providing that information. A state SENSOR contact specialist performs

follow-up with workers and obtains medical records to verify symptoms, circumstances 

surrounding the exposure, severity, and outcome. Using standardized protocol and case 

definitions, SENSOR coordinators at State Departments of Health enter the incident interview 

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

accessible to participating states and EPA. In-depth investigations for case confirmation are 

performed giving the Agency high confidence in the information provided. Although SENSOR 

is not national in scope (it is limited to 12 states) the coverage does include most high-production 

agricultural states and therefore covers the most states where agricultural pesticides are being 

used. The ability to detect trends over time for SENSOR data is limited due to a generally small 

number of incidents and varying degrees with which the states track incidents. 

For NIOSH SENSOR from 1998 to 2007, there are 635 cases reported for chlorpyrifos in the 

database. Of these cases, 348 were reviewed because, in these cases, chlorpyrifos was used as a 

single chemical only and had a certainty classification of definite, probable, or possible, as these 

cases provide more certain information about the potential effects of chlorpyrifos exposure. 

There was one death due to suicide; eight cases were classified as high severity, 60 cases were 

classified as moderate severity, and 279 cases were classified as low severity. Of the 348 cases 

chlorpyrifos-only cases, 18 cases involved children six years old or younger. These latter 

incidents were mostly due to accidental ingestions, misapplications around the home and drift 

from nearby properties. The health effects reported include: neurological, gastrointestinal,

respiratory, ocular, dermal, cardiovascular, and genitourinary. Generally, chlorpyrifos incidents 

involved workers in agricultural or professional application occupations, homeowners and 

individuals at work but their job was not related to pesticide application, and to individuals 

exposed through drift. 
Page 9 of 51

Chlorpyrifos SENSOR non-occupational incidents appear to significantly decrease after 2000 

and continue to decrease until 2007 (see Figure 3). The increases in 2002 and 2005 each 

correspond to a single event involving several people. In 2002, chlorpyrifos was sprayed at a 

school to the exterior of nine buildings during school hours. Twenty one employees working 

inside the buildings experienced symptom including dermal, gastrointestinal, ocular, 

neurological and respiratory symptoms. In 2005, eight workers in a field were sprayed with 

chlorpyrifos. They experienced gastrointestinal, neurological, and respiratory symptoms.

Figure 3. NIOSH SENSOR Chlorpyrifos Incident Count, 1998-2007

On average, less than seven occupational incidents are reported per year for chlorpyrifos in the 

NIOSH SENSOR database. The number of occupational incidents reported appears to remain 

steady from 1998 to 2007. Agricultural workers reported incidents that occurred due to drift 

from adjacent fields, post application exposure, chlorpyrifos application, mixing/loading 

chlorpyrifos, repair and maintenance of equipment, chlorpyrifos transportation and disposal, and 

spills/splashes/leaks of chlorpyrifos onto workers (see Table 1). Application of chlorpyrifos 

appears to lead to the largest number incidents, responsible for 46% reported to NIOSH 

SENSOR from 1998 to 2007.

Table 1. Chlorpyrifos occupational exposure scenarios reported to NIOSH SENSOR, 1998-2007

Exposure Scenario Count Percentage of Total

Applying chlorpyrifos 19 46%

Unknown if occupational or not. 10 24%

Workers in chlorpyrifos treated fields 8 20%

Workers in chlorpyrifos treated fields 8 20%

Spilling/splashing/leaking of chlorpyrifos onto worker 6 15%

Occupational postapplication 2 5%

Mixing/loading chlorpyrifos 2 5%

Repair/maintenance 2 5%

Transport /disposal of chlorpyrifos 2 5%

Total 41 100

0

10

20

30

40

50

60

70

80

90

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

occupational/agricultural non-occupational
Page 10 of 51

3.4. California Pesticide Illness Surveillance Program (PISP)

The Pesticide Illness Surveillance Program (PISP) maintains a database of pesticide-related 

illnesses and injuries. Case reports are received from physicians and via workers’ compensation 

records. The local County Agricultural Commissioner investigates circumstances of exposure. 

Medical records and investigative findings are then evaluated by DPR technical experts and 

entered into an illness registry.

PISP contains both residential and occupational pesticide incidents. PISP has limited coverage 

(only California) and is not particularly useful for trend over time information. However, the 

incident information is entered by professionals with expertise in pesticides, with extensive 

follow-up on each reported case so there is a high level of confidence in the information 

provided for each reported incident.

One hundred and sixty four cases were identified that are attributable to chlorpyrifos-only 

exposures were reported to the California Pesticide Illness Surveillance Program between 1999 

and 2008. Of these cases, 87 were occupational incidents and 77 were non-occupational 

incidents. The health effects reported include: neurological, gastrointestinal, respiratory, ocular, 

dermal, and cardiovascular.

Although there are some spikes in the data which are usually due to a single event affecting 

many people, the chlorpyrifos incidents appear to be decreasing over time for non-agriculture 

related incidents and remaining steady for agricultural related incidents. The spike for nonoccupational incidents in 2005 is one event in which 12 office workers reported symptoms after 

a maintenance worker applied an outdoor chlorpyrifos product on office baseboards and under 

desks to control roaches. They reported experiencing neurological, respiratory, ocular and 

gastrointestinal symptoms including headache, sore throat, lightheadedness, itching or burning 

eyes and nausea. The first spike in agriculture incidents in 2000, is one event in which 17 

postapplication workers reported symptoms after unknowingly entering an orange plantation that 

had been treated with chlorpyrifos the day before. The chlorpyrifos REI for oranges is 5 days. 

The spike for the agriculture related incidents in 2007, is one event in which 26 vineyard workers 

reported symptoms after they were exposed to chlorpyrifos that was being applied on a 

neighboring almond orchard. The vineyard workers reported experiencing respiratory, 

gastrointestinal, neurological, ocular, dermal symptoms including coughing and shortness of 

breath, nausea and vomiting, headache and dizziness, itchy and burning eyes, and itchy skin and 

rash.
Page 11 of 51

Figure 4. California PISP Chlorpyrifos Incident Count, 1999-2008

On average less than nine agricultural incidents are reported per year for chlorpyrifos in the PISP 

database. The number of incidents reported appears to remain steady from 1999 to 2008. 

Agricultural workers reported incidents that occurred due chlorpyrifos drift from adjacent fields, 

postapplication, spill/splash/leak, mixer/loader, and applicator exposure, misuse, equipment 

malfunction, and equipment cleaning (See Figure 5). Unlike in SENSOR, where application was 

the most likely activity involved in incidents, drift of chlorpyrifos appears to be the cause of the 

most occupational incidents in PISP, being responsible for 56% of the cases reported to PISP 

from 1999 to 2008.

Figure 5. Occupational Exposure Scenarios reported to PISP for Chlorpyrifos

0

5

10

15

20

25

30

35

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Occupational Incidents Non-occupational incidents
Page 12 of 51

drift

56%

applicator

7%

equipment 

cleaning

1%

equipment 

malfunction

5%

mixer/loader/appli

cator

2%

misuse

1%

mixer/loader

2%

postapplication

22%

spill/splash/leak

4%
Page 13 of 51

3.5. American Association of Poison Control Centers (AAPCC)

The American Association of Poison Control Centers (AAPCC) is a non-profit, national 

organization founded in 1958 that represents the poison control centers of the United States and 

the interests of poison prevention and treatment of poisoning. All of the calls to a poison control 

center are answered by a medical professional trained to answer questions about poisons.

Additionally, AAPCC reports provide clearly summarized information on pesticide incidents 

within the context of other poisoning events. 

The Agency's findings with respect to decreases in CPY-and OP-associated poisonings 

are consistent with other investigations of AAPCC data. These investigations reported that the 

regulatory restriction of access to pesticides may have an impact on the number of human 

exposure incidents. Specifically: 

Blondell (2007) examined Poison Control Center data from 1995 to 2004. Rates were 

calculated for pesticide type and selected pesticide classes based on estimated total 

United States population and proportion of population served. Pesticides as a 

proportion of poisoning to all substances over the years and vital statistics on deaths 

were examined to validate trends. Blondell found that from 1995 to 2004 there has 

been an overall 42% decline in estimated serious symptomatic exposures to pesticides 

reported to PCC in the United States. At least 60% of this decline appears to be 

unrelated to any overall reporting bias. Specifically, organophosphate insecticides 

declined 72%. The author noted that declines in PCC-reported pesticide exposures 

are not fully understood because of the absence of denominator data on use and 

historical data on use patterns.

Sudakin and Power (2007) also utilized national Poison Control Center data to assess 

whether the risk mitigation decision had an impact on the number of incident cases 

involving organophosphates in the United States. Organophosphate exposure incident 

data were extracted from Annual Reports of the American Association of Poison 

Control Centers for the years 1995 to 2004. They observed a reduction in incident 

cases reported to poison control centers in the United States involving 

organophosphate insecticides. The reduction was temporally associated with risk 

mitigation decisions by the U.S. EPA to phase out the use of organophosphates from 

residential environments.

Another investigation of PCC data by Power and Sudakin (2007) found that the 

restricting or banning of access to certain pesticides may have a significant effect on 

exposures to alternative classes of pesticides. They noted an increase in cases 

involving pyrethrins and pyrethroids associated with the US EPA’s regulatory 

decision to phase out organophosphate insecticides in residential environments. 

Power and Sudakin extracted pyrethrin and pyrethroid insecticide exposure data from 

the AAPCC TESS annual reports from 2000 to 2005. They examined pyrethrin and 

pyrethroid incidents by total exposures for each year, and stratified exposures by age 

range, reason, number of cases treated in a health care facility, and medical outcome. 

Cases were examined as a proportion of all insecticide exposures. TESS data showed 

a clear increase in cases involving pyrethrins and pyrethroids. The increase was 

temporally associated with the phase out of organophosphates from residential uses. 
Page 14 of 51

AAPCC produces an annual summary report giving statistics and information on all the 

poisonings reported to PCCs in a calendar year. The AAPCC annual summary data do not break 

down the incident data in terms of chlorpyrifos per se but instead report it only as

organophosphate incident data. The Agency examined the organophosphate data from 2002 to 

2009 in order to update the Blondell (2007) examination of the PCC data from 1995 to 2004 and 

found that from 2002 to 2009, organophosphate exposures reported to the AAPCC have

continued to decline showing a 64% decrease in organophosphate exposures reported over that 

eight year period. 

3.6. Summary of Trends in Chlorpyrifos Incidents

Chlorpyrifos non-occupational incidents appear to be decreasing over time across multiple 

incident databases. In IDS, reports of incidents have decreased by 95% from 2002 to 2010. In 

NPIC reports of incidents have decreased by 92% from 2002 to 2010. This correlates well with 

the phase out/cancellation of the chlorpyrifos residential products. 

As of December 31, 2001, all products labeled for homeowner use, except containerized ant and 

roach baits in child-resistant packaging and all products labeled for use in schools and parks (both 

indoors and out) were canceled. However, there are still some homeowner/residential incidents 

reported as recently as May 2010 (IDS) and July 2010 (NPIC). Closer review of the most recent 

cases shows that they are due to eating food from a family owned farm without adhering to the preharvest interval, drift from a neighboring farm, and residential misuse or spills and splashes from the 

use of cancelled products that had been stored in the home. 

Chlorpyrifos occupational incidents appear to be constant over time in both the PISP and NIOSH 

SENSOR databases. This corresponds well with EPA’s agricultural market analysis that suggests

that chlorpyrifos usage has remained relatively constant since 2001 (USEPA 2011). 

4. Medical Toxicology and Medical Case Reports

Medical human observational data involving pesticides are another source of information that 

can be used to evaluate risks of chlorpyrifos. Medical case reports are evaluations of particular 

patients that describe the symptoms, signs, diagnosis, treatment, and follow-up of an individual 

patient. Case series can be similar to case reports, but instead focus on multiple patients with 

similar exposure, treatment and/or symptoms/signs. Case reports and case series provide insight 

into the potential effects of pesticide exposure on humans assessed by health professionals. It is 

important to remember, however, that oftentimes, the exposure scenarios associated with medical 

case reports and series are extreme (suicides, attempted suicides, or non-accidental ingestions) 

and bear little resemblance or similarity to more typical accidental or inadvertent exposures. 

Nevertheless, examining these cases can have value in that they illustrate the effects of frankly 

toxic doses and allow observation of what may be important sequella. In addition, examination 

of these cases can permit comparisons with the effects observed in laboratory animals in high 

dose toxicology studies. For pesticides where much information is available, there may be 

reviews and syntheses of information that professionals utilize to help diagnose and treat 

pesticide exposure (e.g., ATSDR- Case Studies, Recognition and Management of Pesticide 
Page 15 of 51

Poisoning Manual). These reviews sometimes merge information from animal toxicity studies 

and in vitro studies in addition to human observational data to present a more complete picture of 

the toxicology of the pesticide. 

Medical information on pesticides are found in many locations; however the Agency has relied 

on information obtained from databases for the period from 1993 to the present, querying the 

National Library of Medicine (PubMed, TOXNET), Google Scholar, as well as the CDC and 

ATSDR databases to identify relevant pesticide medical information. Specifically, the Agency 

looked across the following databases for this assessment:

PUB MED comprises more than 20 million citations for biomedical literature from 

MEDLINE, life science journals and online books.

TOXNET consists of HSDB (Hazardous Substances Data Bank) which contains 

comprehensive peer-reviewed toxicology data for about 5,000 chemicals.

ATSDR Case-Studies provide information regarding clinical findings, treatment and 

current knowledge regarding pesticides.

NHANES biomonitoring data provides information on environmental exposures 

based on measures of environmental chemicals or metabolites in blood or urine.

Google Scholar is a web search engine that indexes the full text of scholarly literature

across an array of publishing formats and disciplines. It includes most peer-reviewed

online journals of Europe and America's largest scholarly publishers.

Although there may be other sources of medical information relating to pesticide exposures , the 

Agency is confident that considering the sources listed and described above captures the 

critical/impactful medical information, especially concerning human health effects of 

chlorpyrifos. A medical literature search on chlorpyrifos was done, using the terms (or key 

concept) “chlorpyrifos poisoning” “chlorpyrifos AND health effects”, “chlorpyrifos toxicity”, 

“chlorpyrifos AND case study” to search Pub Med. Google advanced search was used to 

retrieve full text articles. From PubMed 1044 citations were recovered but many of them were 

not specific to chlorpyrifos, or on human health effects. Twenty eight full text articles related to 

chlorpyrifos and human health effects, toxicokinetics and toxicodynamics were reviewed. 

4.1. Medical Toxicology

Most of the toxic signs and symptoms presented by patients with chlorpyrifos poisoning are due 

to inhibition of acetylcholinesterase enzyme (AChE) which terminates the action of the 

neurotransmitter acetylcholine. Chlorpyrifos inactivates AChE by phosphorylating the serine 

hydroxyl group located at the active site of AChE, resulting in an excessive accumulation of the 

neurotransmitter acetylcholine (ACh). This leads to overstimulation of muscarinic and nicotinic 

receptors in synapses and neuromuscular junctions. Muscarinic and nicotinic receptors are 

acetylcholine receptors classified according to their response to Amanita muscaria mushroom 

toxin and nicotine in tobacco. The clinical symptoms result from an interaction of 

parasympathetic, sympathetic, somatic motor as well as central nervous effects (Aaron and 

Howland, 1997 and Thompson and Richardson, 2004). 
Page 16 of 51

There are three generally described syndromes that result from organophosphates including 

chlorpyrifos exposure:

Acute cholinergic syndrome

Intermediate syndrome (starts about 1-4 days after the acute syndrome)

Delayed neuropathy

Following the description of each of these syndromes, medical case reports obtained from the 

literature reflecting these three different syndromes are provided in Table 1. It is important to 

note that these effects are observed only following severe poisoning incidents or intentional/ 

suicidal exposures and are only rarely reported in incident databases. 

Acute Cholinergic Syndrome

Acute cholinergic syndrome can include the following central nervous system (CNS) effects: 

confusion, drowsiness, difficulty in concentrating, slurred speech, restlessness, bizarre behavior, 

ataxia, tremors, seizures, and coma. In severe intoxication, death can result from respiratory 

failure. Respiratory failure is due to multiple factors: respiratory muscle weakness (particularly 

the diaphragm), central respiratory depression and pulmonary factors such as pulmonary edema, 

bronchoconstriction, bronchorrhea (Singh G. et al., 2009).

Muscarinic mediated effects by organ systems include the following:

Cardiovascular - bradycardia, hypotension

Respiratory - rhinorrhea, bronchorrhea, bronchospasm, cough, severe respiratory 

distress

Gastrointestinal – excessive salivation, nausea and vomiting, abdominal pain, 

diarrhea, fecal incontinence

Genitourinary – urinary incontinence

Ocular - Blurred vision, miosis (constricted pupil)

Glands - Increased lacrimation, diaphoresis (excessive sweating)

Nicotinic mediated signs and symptoms by organ system include:

Cardiovascular – may cause mild hypertension, and tachycardia

Neuromuscular junctions - may cause initial stimulation (muscle fasciculation, 

cramping), followed by weakness, and paralysis of muscles including diaphragm 

muscle.

Dermal – excessive sweating

Intermediate Syndrome

Intermediate syndrome is a development of weakness in respiratory muscles, proximal muscle 

groups of limbs, and neck flexor muscles after an episode of acute cholinesterase inhibitor 

poisoning. It is so named because it can occur between 1-4 days after the acute cholinergic crisis 
Page 17 of 51

and the onset of organophosphate-induced delayed neuropathy (OPIDN) (Karalliedde and 

Senanayake 1989; Kwong 2002). Intermediate syndrome may occur from 20-70% of patients 

and it may last from 4-18 days. As discussed above, differing sensitivity is expected in the 

population. According to Aygun et al. (2002), intermediate syndrome may be due to damage 

secondary to over stimulation of nicotinic receptors within sympathetic ganglia and at skeletal 

myoneural junction. However, Katz and Brooks (2010) thought that it may be due to suboptimal 

treatment during the acute stage. Respiratory muscle weakness causing respiratory depression 

usually requires ventilator support. 

Chlorpyrifos has high lipophilicity, and is able to readily access the central nervous system 

(CNS). It is more likely to cause CNS effects such as extrapyramidal manifestations and 

Parkinsonism like syndrome (cogwheel rigidity of extremities, bradykinesia, resting tremor, 

choreoathetosis, and masked face) than other organophosphates (Kventsel et al., 2005). Hsieh et 

al. 2000 proposed that Parkinsonism like syndrome may be due to abnormal modulation of the 

nigrostriatal dopaminergic system. Some cases exhibited Parkinsonism without antecedent or 

concomitant chlolinergic syndrome.

Salvi et al., 2003 stated that workers exposed to chlorpyrifos developed clinically significant 

extrapyramidal symptoms. Tremor was the predominant symptom; also mask-like face and 

reduced pendular arm movement were commonly observed. 

Goel.et al., 2006 reported that a 21 year old female with a history of ingestion of heavy dose of 

organophosphate developed extrapyramidal symptoms (tremor, mask- like face, cog wheel 

rigidity, hypokinesia, and occulo-gyric crisis) on the 10th day. Magnetic resonance imaging 

(MRI) showed symmetrical hyper intensities in the Putamen and Caudate nucleus. 

Delayed Neuropathy

Aygun et al. (2002) and Sennayake et al. (1993) mentioned that chlorpyrifos poisoning may 

cause delayed neuropathy, also known as organophosphate induced delayed neuropathy 

(OPIDN). It is a neurobehavioral and sensory-motor distal axonopathy. It was mentioned that 

inhibition (phosphorylation) of neuropathy target esterase (NTE) enzyme in neurons leads to 

axonal degeneration and demyelination of the nerves (Nand et al., 2007). According to Eaton et 

al., 2008, the severity of neuropathy correlates with the degree of NTE enzyme inhibition. 

Glynn P., 2005 found that organophosphate inhibition of NTE causes disruption of neuronal cell 

membrane phospholipid homeostasis and endoplasmic reticulum functions which interferes with 

axonal transport of protein and other substances. The distal parts of long axons are particularly 

vulnerable to loss of these support functions. 

Patients may suffer from impaired memory and concentration, disorientation, severe depression, 

irritability, confusion, headache, speech difficulties, delayed reaction times, nightmares, 

drowsiness and insomnia (Cox, 1994). Mostly patients presented 3-5 weeks after 

organophosphate poisoning with lower extremity weakness, a high stepping gait, calf pain, leg 

cramps, and glove and stocking type of sensory loss. Large distal neurons tend to be affected 

first, causing atrophy of calf muscles, foot drop, and ataxia. A nerve conduction study showed 

reduced or absent compound muscle action potential (CMAP) in motor nerves and reduced 
Page 18 of 51

conduction velocity in both motor and sensory nerves. Residual sensory and autonomic 

dysfunction may persist for years after cessation of exposure (Senanayake, 1981). 
Page 19 of 51

4.2. Medical Case Reports

Table 2: Medical Case Reports of Chlorpyrifos Poisoning

Article Title Author Year Summary

Medical Case Reports Regarding Acute Cholinergic Symptoms

Non-accidental chlorpyrifos 

poisoning-an unusual cause of 

profound unconsciousness

Jiun-Chang Lee

Kuang-Lin Lin

Jainn-Jim Lin

et al.

2009 A 5 year 6 month old boy suffered from abdominal pain, excessive salivation, 

lacrimation, vomiting, shortness of breath, pin point pupils, prolonged pause in 

breathing, and deep unconsciousness, after being poisoned with chlorpyrifos by his 

step-mother. His plasma cholinesterase level was <84μ/l (normal range, 3,000-9,300 

μ/l). Brain computed tomogram did not show focal brain lesion. One hour after the 

intravenous atropine treatment was started; pin point pupils, excessive salivation and 

lacrimation were improved. He regained consciousness after two days and the 

ventilator support was stopped on the fifth day.

Acute chlorpyrifos poisoning in 

pregnancy: A case report

Solomon G.M.

Moodley J.

2007 A 22 year old pregnant woman presented with generalized tonic-clonic seizures, 

vomiting profusely with garlic odor, fecal incontinence, pinpoint pupils, muscle 

weakness, and secretions in lungs after drinking unknown amount of chlorpyrifos to 

commit suicide. Although her symptoms improved with atropine administration, she 

went into premature labor two days after the initial event, and delivered a 1.2 kg live 

baby that died on day 2 due to prematurity. She was discharged from the hospital two 

weeks later.

Chlorpyrifos poisoning treated with 

ipratropium and dantrolene: a case 

report.

Shemesh, I., Bourvin, 

A., Gold, D. & 

Kutscherowsky, M.

1988 A 38-year-old man drank an undefined quantity of a 25% chlorpyrifos solution. He 

presented with stupor, respiratory distress, and had complete inhibition of serum ChE 

activity. The man was successfully treated with extensive antidote therapy and artificial 

respiration and was discharged from the hospital one month after the incident. His 

serum ChE activity was still undetectable at that time.
Page 20 of 51

Medical Case Reports Regarding Intermediate and Extra-Pyramidal Syndrome

Article Title Author Year Summary

Intermediate syndrome after 

exposure to chlorpyrifos in a 16-

month old girl

Mattingly J.E.

Sullivan J.E.

Spiller H.A.

Bosse G.M.

2003 A 16-month old girl accidentally ingested chlorpyrifos and developed lethargy, 

difficulty in breathing and pulmonary edema. She was treated with pralidoxime and 

also put on the mechanical ventilator. At 24.5 hour post-ingestion, the child had a 

normal neurologic examination, showed no signs of cholinergic symptoms, and was 

extubated. However, at 27.5 hour post-ingestion she became flaccid, with slow heart 

rate and irregular respiration (temporary cessation of respiration). She was emergently 

re-intubated. This is consistent with the characteristic of Intermediate syndrome 

(development of respiratory failure after recovering from the initial episode).

Scopolamine treatment for severe 

extra-pyramidal Signs following 

organophosphate (chlorpyrifos) 

ingestion

Kventsel I.

Berkovitch M.

Reiss A.

Kozer E.

2005 A 17-year-old girl was admitted to the pediatric ward 2 hours after ingesting 150 mL of 

a household pesticide containing chlorpyrifos. Over the course of 36 hours, she 

gradually developed extra-pyramidal signs and became comatose. Her plasma 

cholinesterase level was 146 U/L (Normal value- 5300-12900 U/L). She did not 

respond to questions and commands or to pain stimuli. She vomited four times but did 

not have other muscarinic signs and symptoms. She was treated with intravenous 

scopolamine. Within few minutes, the patient started to respond to verbal commands 

and answered simple questions, rigidity subsided, and she was able to sit in bed. She 

was discharged after 4 days with no neurological sequelae. Scopolamine is able to 

cross the blood brain barrier better than atropine and exerts its effects by acting as a 

competitive antagonist at muscarinic acetylcholine receptors. Her plasma 

cholinesterase level returned within normal range (8160 U/L) three months after the 

ingestion. This is one of the chlorpyrifos poisoning cases presented with 

extrapyramidal effects with minimal muscarinic symptoms.

 Medical Case Reports Regarding Delayed Neuropathy

Article Title Author Year Summary
Page 21 of 51

Organophosphate induced delayed 

neuropathy

Nand N.

Aggarwal HK

Bharti K.

Chakrabarti D.

2007 A 19 year old male ingested 100 ml of chlorpyrifos in an attempt to commit suicide; he 

developed pin point pupils, and excessive secretions in lungs. After 24 hours he had 

respiratory paralysis and shock, and was put on mechanical ventilation for 16 days. He 

recovered except slight weakness of proximal muscles of lower limbs and was 

discharged from the hospital. After six days of discharge, he developed distal 

weakness in the lower limbs which progressed in next 3-4 days to the extent that he 

could not walk without support. Electrophysiological examinations revealed markedly 

reduced CMAP (compound muscle action potential) and reduced motor nerve 

conduction velocity in tibial nerve of both lower limbs. Sensory nerve action potential 

was mildly reduced. These findings were consistent with characteristics of OPIDN 

which has a predominant motor axonal neuropathy involving distal muscles of lower 

limbs.

Permanent paralysis at sites of 

dermal exposure to chlorpyrifos

Meggs W. J. 2003 A case presented with OPIDN after a mixed dermal and inhalational exposure to 

chlorpyrifos. This case is unique because the neuropathy developed only in those 

regions with direct skin contact to chlorpyrifos. A 61 year old carpenter sprayed a nest 

of termites with the product containing 45% chlorpyrifos without protective equipment. 

The product got on his hands, lower arms, lower legs and feet. He developed nausea, 

vomiting, abdominal cramps, weakness in arms and legs, bilateral shoulder pain, chest 

pain and numbness in the left hand and arm, 30 minutes after using the product. 

Although atropine and pralidoxime were given, electromyogram showed widespread 

peripheral neuropathy which was progressing. Pralidoxime was repeated on the third 

day. However, he never regains use of his hands and has disturbed gait (unable to clear 

his left foot when walking). Follow up after ten years showed decreased grip strength, 

inability to dorsiflex his left leg and hopping on his right foot to clear his left foot 

which has a marked foot drop. During the course of his illness, patient did not develop 

mental status change, or other neuropsychiatric disability. This case indicates that 

exposure to chlorpyrifos can lead to permanent paralysis at the sites of dermal exposure 

in spite of a relatively mild systemic poisoning.
Page 22 of 51

Severe and prolonged neurologic 

toxicity following subcutaneous 

chlorpyrifos self-administration

Soummer A.

Megarbane B.

Boroli F.

Arbelot C.

et al.

2011 An interesting case of prolonged coma (6 weeks), delayed cholinergic phase and 

prolonged neurologic toxicity following self injection with chlorpyrifos subcutaneously 

on both arms was reported. Although minimal muscarinic signs were found at the time 

of admission, he developed respiratory failure after twenty four hours and was put on 

the ventilator. Large surgical wound debridement was done for extensive necrotizing 

fasciitis of both forearms; also daily wound debridement for necrosis and sepsis. On 

various occasions, several minutes after wound care, muscarinic symptoms such as 

hypersalivation, bronchorrhea (excessive secretions in airways) and bradycardia 

occurred, were relieved by atropine. Authors thought these symptoms were due to 

prolonged and continuous release of chlorpyrifos from the body fat and forearm 

muscles acting as reservoirs (despite repeated wound debridement). They found 

chlorpyrifos in serum till Day 30, and metabolites in plasma and urine till Day 100. 

Chlorpyrifos concentration in the forearm muscle was 44 μg/kg on Day 50. Plasma 

butyrylcholinesterase activity remained low <500 IU/L (Normal range 8000-18,000) 

until Day 60. RBC cholinesterase level was 1138 IU/L (Normal range 2800-5200) on 

admission and became normal on Day 60. Patient was discharged at Day 120; he 

remained tetraparetic (weakness on all four limbs), but proximal muscle testing showed 

some improvement. However, distal muscle testing showed persistent severe deficits. 

At one year follow-up, persistent severe muscle weakness was found indicating 

irreversible organophosphate related peripheral neuropathy.

Life-threatening organophosphateinduced delayed polyneuropathy in 

a child after accidental chlorpyrifos 

ingestion.

Aiuto, L.A., Pavlakis, 

S.G. & Boxer, R.A.

1993 A 3 year old child presented with cholinergic syndrome after chlorpyrifos exposure. 

Patient’s BuChE level got back to normal within 3 days of treatment. However, he 

developed bilateral vocal cord paralysis while he was in hospital. Tracheostomy was

performed and maintained for more than 50 days. Patients recovering from serious 

organophosphate poisoning should be monitored for the development of vocal cord 

paralysis which can be a fatal complication. 

Isolated bilateral recurrent 

laryngeal nerve paralysis: A 

delayed complication of 

organophosphorus poisoning.

 

Silva D

Sanmuganathan P.S.

Senanayake N.

1994 A 21-year-old man who ingested an unknown quantity of chlorpyrifos showed acute 

cholinergic effects comprising pupillary constriction, excess secretions, tachycardia, 

and impaired consciousness. He was treated with atropine and PAM (pralidoxime). 

Twenty-eight days after exposure, bilateral vocal cord paralysis developed. The patient 

received prolonged intubation and ventilator support.
Page 23 of 51

5. NHANES Biomonitoring Data

In a survey of a random sample of U.S. adults (n = 929) conducted in the late 1980s and early 

1990s (Hill et al., 1995) estimated that detectable levels of a metabolite of chlorpyrifos (TCPy) 

are present in the urine of 82% of U.S. adults, with a mean level of 4.5 μg/L. According to 

NHANES 2001-2002, urinary concentrations of 3,5,6-TCPy were highest in 6-11 year old group, 

and the levels were 3.76 (50th percentile), 6.22 (75th percentile), 12.2 (90th percentile) and 16.9

μg/g of creatinine (95th percentile). Adult (20-59) year old group levels were 1.64, 3.11, 5.50, 

and 7.44 μg/g of creatinine, respectively. 

6. Epidemiological Data

Epidemiological data may be used to assist in the identification and characterization of human 

health hazards in the environment. Ideally, these data may be used quantitatively to estimate an 

exposure-response relation in the human population, as opposed to experimental animal models. 

In this assessment, the epidemiologic data related to chlorpyrifos exposure is used qualitatively 

to further describe potential human health hazards in certain study populations. Specifically, data 

from two distinct sources are considered: the Agricultural Health Study (AHS), and studies from 

three independent university-based children’s health study populations (Columbia University, 

Mt. Sinai Hospital, and University of California, Berkeley). Results of these investigations are 

briefly summarized below. 

The AHS is a high quality, prospective epidemiology study evaluating the potential associations 

between pesticide use and various cancer and non-cancer health outcomes among a large 

population of private and commercial pesticide applicators (N=57,310). The AHS chlorpyrifos 

carcinogenicity studies have been summarized in the memorandum “Chlorpyrifos 

Carcinogenicity: Review of Evidence from the U.S. Agricultural Health Study (AHS) 

Epidemiologic Evaluations 2003-2009,” (Christensen, D388167, 6/16/2011). In the 

memorandum, two types of AHS studies were reviewed: studies which compare the proportion 

of chlorpyrifos users between those with and without certain cancers (referred to as nested casecontrol studies) and cohort studies which compare cancer incidence between those exposed to 

chlorpyrifos and those not exposed to chlorpyrifos. Both the nested case-control and the cohort 

studies published in the AHS to date are hypothesis-generating in nature i.e., no a priori

associations were hypothesized and multiple analyses (comparisons) were performed in many 

instances, these investigations are among the first ever published examining a chlorpyrifoscancer association and, as hypothesis-generating studies, these results require replication to 

confirm and fully understand the nature of the association between chlorpyrifos use and cancer 

outcomes, i.e., whether any observed statistical associations are in fact likely to be causal in 

nature. 

While all of these investigations were hypothesis-generating in nature, initial findings for lung 

and colorectal cancer are notable. In both of these investigations, the association is observed in 

both cohort and case-control studies at different points in time, and within both study states (NC, 

IA). In addition, researchers observed a monotonic, linear trend across exposure categories, and a 

statistically significant difference in cancer risk between upper- and lower-category exposure 

groups. However, these results represent initial reports only, are the result of many different 
Page 24 of 51

statistical tests, and lack biological explanation at this time. Regarding hormonally-modulated 

cancer sites, there is only limited evidence that chlorpyrifos may play a role in either prostate 

cancer, among men with a family history of prostate cancer, or breast cancer, among female 

spouses of farmers/applicators. With regard to each of these afore mentioned anatomical cancer 

sites, additional research is needed to better define the nature of this association. There is no 

evidence presented within this occupational cohort that lifetime chlorpyrifos exposure is related 

to cancers of the pancreas, brain, esophageas, kidney, or cutaneous melanoma, 

lymphohematopoietic cancers combined or non-Hodgkin’s lymphoma, leukemia, and multiple 

myeloma. EPA will continue to monitor the literature for additions to the chlorpyrifos cancer 

database in the future.

In addition to evaluations of the carcinogenic potential of chlorpyrifos within the Agricultural 

Health Study (AHS), EPA is also considering the results of epidemiological evidence of the 

compound’s developmental neurotoxicity. Specifically, there are three major prospective 

epidemiology cohort studies evaluating pre- and post-natal pesticide (chlorpyrifos and/or OPs) 

exposure in mother-infant pairs with birth outcomes, and childhood neurobehavioral and 

neurodevelopment outcomes in neonates, infants, and young children. Two of the cohorts have 

also investigated the role of genetic susceptibility (PON1) in the association between pesticide 

exposure and adverse birth outcomes and neurodevelopmental effects. In 2008, EPA consulted 

the SAP on the use of these three cohort studies in mothers and their children. Details of this 

analysis and discussion are provided in the chlorpyrifos docket (draft Appendix D Epidemology 

at http://www.epa.gov/scipoly/sap/meetings/2008/091608_mtg.htm.) EPA plans to finalize the 

science documents reviewed by the SAP in the upcoming months. Funded by multiple Federal 

Agencies, including US EPA, the three studies originate from: (1) Columbia University, NYC, 

(2) Mt Sinai, School of Medicine, NYC, and (3) University of California at Berkeley (Center for 

Health Assessment of Mothers and Children of Salinas, CHAMACOS). The first two study 

populations include multi-ethnic, urban low income mother-infant pairs, and the latter reflects a 

farm worker/agricultural worker study population1. The Columbia study focuses on chlorpyrifos 

in cord blood and the latter two studies assess the non-specific organophosphate (OP) metabolite 

dialkyl phosphates (DAPs) in maternal urine, and link these biomarkers of exposure with 

associated health outcomes in children that were exposed in utero. The results and interpretation 

of these studies including the integration of the toxicological and epidemiological databases, are 

more fully discussed by EPA in the documents “Chlorpyrifos Hazard and Dose Response 

Characterization,” as well as the risk assessment. These results are briefly summarized here.

Briefly, researchers have evaluated the association between prenatal or perinatal chlorpyrifos 

exposure and developmental neurotoxic health effects observed in neonates, infants, and children 

through age 7. In EPA’s review of the epidemiologic evidence concerning potential 

neurodevelopmental effects of prenatal or early postnatal chlorpyrifos and/or OP exposure, EPA 

noted consistency across the studies, i.e. delays in cognitive achievement, motor control, social 

behavior, and intelligence measures that were reported in all three prospective cohorts 

(Columbia, Mt. Sinai and CHAMACOS) in children 2-3 years of age. However, the degree to 

which chlorpyrifos is implicated in these outcomes varies. 

 

1 The Mt Sinai study included inner city, black, Hispanic and white women, while the Columbia study evaluated 

inner city African American and Dominican. The Berkley study included homogenous Latino women from 

Agricultural communities.
Page 25 of 51

More recently, in April 2011, these same researchers published results indicating that in utero

chlorpyrifos and/or OP exposure may have persistent neurodevelopmental effects for school age 

children up to age 7 using the Weschsler Intelligence Scale for Children-IV. Since these studies 

were recently published, EPA has not conducted a full evaluation of these recent publications (of 

the same cohort), but will consider these human epidemiological studies along with the available 

empiricial data in a full weight of evidence analysis in the final assessment. 

There are several strengths of the epidemiological database linking prenatal chlorpyrifos and 

other OP exposure with neurodevelopment effects in neonates, infants, young children and 

school aged children. Specifically, the measurement of the neurodevelopmental outcomes (e.g., 

Brazelton index, Bayley scale, and the Weschlar Intelligence Scale) are accepted valid and 

reliable measurement tools in clinical and epidemiologic research. In addition, the use of 

biological markers of exposure [i.e., cord blood concentration of chlorpyrifos or maternal urinary 

dialkylphosphate (DAPs)], are more accurate and reliable measures of prenatal exposure than 

other forms of exposure assessment such as self-report questionnaire. Notably, the exposure 

measurements (biomonitoring and/or personal air monitoring) were well coordinated with the 

exposure period of interest (third trimester for birth outcomes). The Columbia study measured 

chlorpyrifos in umbilical cord blood at delivery, and maternal blood measurements during 

pregnancy and delivery. The researchers in each of these cohorts utilized robust and appropriate 

statistical analysis methods to model the exposure-response association including adjustment for 

potentially confounding variables.

All three cohort studies have limitations that include multiple chemical exposures and exposure 

to other organophosphates. The exposure classification is based on maternal spot urinary 

samples for the Mt. Sinai and CHAMACOS studies and maternal and cord blood samples in the 

Columbia Study that may not necessarily represent total chlorpyrifos or OP exposure throughout 

pregnancy because these pesticides have short half-lives. However, the prevalence of exposure 

among these cohorts based upon a one-time sample indicates the total exposure may be greater 

than measured (exposure measurement error likely exists), and results of meconium analyses in 

the Columbia cohort indicate chlorpyrifos exposure occurred throughout pregnancy. Meconium 

is considered to be an integrative measure of exposure throughout pregnancy. In addition, the 

Mt. Sinai and CHAMACOS studies associate increased maternal urinary DAP levels with 

increased mental delays in children. DAP metabolites are non-specific metabolites that result 

from several OP pesticides, so it is difficult to determine which OP compound may be 

contributing most to the adverse findings.

7. CONCLUSION

This review considers different types and sources of human observational information (human 

incident data, medical data/information, and epidemiological information) in an effort to 

consider different lines of evidence that may inform the re-evaluation of chlorpyrifos in this 

phase of Registration Review. The symptoms reported in the medical human observational data 

and human incident data reviewed for this report are mutually supportive. Specifically, the 

symptoms reported for both types of observational data include cardiovascular, respiratory, 
Page 26 of 51

gastrointestinal, nervous system and ocular symptoms. The Agency’s risk mitigation measures 

including canceling all homeowner use product registrations (except ant bait stations), and 

canceling uses in schools and parks where children may be exposed appears to have led to a 

decrease in the number of incidents reported in residential areas. The databases that were 

reviewed (OPP Incident Data System, National Pesticide Information Center [NPIC], NIOSH 

Sentinel Event Notification System for Occupational Risks [SENSOR], and California Pesticide 

Illness Surveillance Program Incident Data [CA PISP]) showed the number of incidents 

associated with chlorpyrifos significantly declined post-2002 and this correlates well with the 

phase out/cancellation of the almost all chlorpyrifos residential products as of December 31, 

2001. In addition, the Agency's findings are consistent with other incident cases investigations 

of American Association of Poison Control Centers (AAPCC) data which have reported a 

decrease in the number of chlorpyrifos incidents that is temporally associated with the phase 

out/cancellation of most residential chlorpyrifos products. For AAPCC data, the mean annual 

number of reports for chlorpyrifos in the pre- and post-announcement phases was 214 and 39.3, 

respectively (Stone et al. 2009). In IDS, there were 43 incidents reported in 2002 and only six 

reported in 2009.

Chlorpyrifos occupational incidents, reported in CA PISP and SENSOR databases, appear to be 

constant over time, despite risk mitigation implemented including reduced application rates and 

seasonal maximum limits, increased retreatment intervals, increased PPE and/or use of 

engineering controls were required as well as increased re-entry intervals (REIs) for a number of 

crops. However, a number of these incidents appear to be due to accidents and misuse. In 

NIOSH SENSOR applying chlorpyrifos appears to lead to the most incidents, being responsible 

for 46% reported to NIOSH SENSOR from 1998 to 2007; in PISP, drift of chlorpyrifos from 

adjacent fields appears to be the cause of the most incidents, being responsible for 56% of the 

cases reported to PISP from 1999 to 2008. 

The chlorpyrifos incidents reported have declined substantially (95%) among residential users 

from 2002 to May 27, 2010, but the occupational incidents reported remain the same. The 

incidents reported have been reviewed and, overall, the numbers and severity of incidents 

associated with chlorpyrifos use are not of public health concern, but we will continue to monitor 

these incidents and remain alert for any changes in trend or patterns.

The Agency examined epidemiologic data from two distinct sources to support this risk 

assessment: the AHS and results from three university-based children’s health cohorts. 

Regarding the AHS studies, EPA notes that the results for the potential link between 

occupational use of chlorpyrifos over the lifetime and both lung and colorectal cancers are 

notable, given the strength and consistency of the association; however as preliminary, 

hypothesis-generating studies, additional research and follow-up is needed to clarify and verify 

the nature of the association. EPA will continue to monitor the literature for additions to these 

two databases. Regarding other cancer sites, there is limited, preliminary evidence that 

chlorpyrifos may plays a role in either prostate or breast cancer, and no evidence to suggest that 

chlorpyrifos is associated with pancreatic cancer, melanoma, brain, esophageal, kidney, all 

lymphohematopoietic cancers combined and NHL, leukemia, and multiple myeloma. Regarding 

the putative association between prenatal chlorpyrifos exposure and neurodevelopmental effects 
Page 27 of 51

in neonates, and young children, EPA will continue to follow to this issue and further evaluate 

the associated epidemiological and toxicological science in the coming months.
Page 28 of 51

8. References

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Pediatrics, 122, 658-660.

AARON, C.K., HOWLAND, M.A. 1997. Insecticides: Organophosphates and carbamates. 

Appleton & Lange, 1429-1449.

ALBERS, J.W., GARABRANT, D.H., STANLEY, B., RICHARDSON R.J. 2010. Paraoxonase 

status and plasma butyrylcholinesterase activity in chlorpyrifos manufacturing workers. 

Journal of Exposure Science & Environmental Epidemiology, 20(1),79-89 

ATSDR, 1997. Toxicological Profile for Chlorpyrifos. 

http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=495&tid=88

AYGUN, D., DOGANAY, Z., ALTINTOP, L.ET AL. 2002. Serum acetylcholinesterase and 

prognosis of acute organophosphate poisoning. Journal of Toxicology, vol40, No7, 903-

910.

BICKER, W., LAMMERHOFER, M., GENSER, D., KISS, H. & LINDNER, W. 2005. A case 

study of acute human chlorpyrifos poisoning: Novel aspects on metabolism and 

toxicokinetics derived from liquid chromatography-tandem mass spectrometry analysis of 

urine samples. Toxicology Letters, 159, 235-251.

BLONDELL, J. M. 2007. Decline in pesticide poisonings in the United States from 1995 to 

2004. Clinical Toxicology, 45, 589-592.

BOUCHARD 2011 Maryse F. Bouchard, Jonathan Chevrier, Kim G. Harley, Katherine

Kogut, Michelle Vedar, Norma Calderon, Celina Trujillo, Caroline Johnson, Asa 

Bradman, Dana Boyd Barr, and Brenda Eskenazi. “Prenatal Exposure to 

Organophosphate Pesticides and IQ in 7-Year-Old Children”;

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ENGEL, S. M., BERKOWITZ, G. S., BARR, D. B., TEITELBAUM, S. L., SISKIND, J., 

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Page 32 of 51

Appendix A: Chorpyrifos Main IDS Report

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

12570 11 4-Jan-02 RAID ANT BAITS 

(DISCONTINUED IN 

2001)

482200335 OXFORD MI HC A 3 year old Female 

Child reported Ear 

Infection

12639 23 9-Jan-02 DURSBAN MONKTON MD HC Unknown Adult (18-64 

years old) Male, 

Symptoms Not 

Mentioned

12694 1 4-Feb-02 LORSBAN WEST 

MONROE

LA HB A 23 month old Male 

Child reported Muscle 

weakness, Tachycardia, 

Drowsiness/Lethargy

12694 4 7-Feb-02 DURSBAN TC 6271900047 TALLAHASSE

E

FL HC A 11 month old Female 

Child reported Edema, 

Lacrimation

12729 5 12-Mar-02 DURSBAN MIDDLEBERG GA HC A 73 year old Female 

reported Shortness of 

Breath, 

Dizziness/Vertigo, 

Coughing/Choking, 

Bronchitis

12754 3 26-Mar-02 AFFRONT GEL 

INSECTICIDE

272400487 BURLINGTON VT HC A 47 year old Female 

reported Irritation/Pain, 

Lacrimation

12796 16 22-Mar-02 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 PA HC A 66 year old Male 

reported Lacrimation, 

Diarrhea, Pneumonia, 

Congestion

12855 2 30-Jan-02 LORSBAN (NONSPECIFIC)ARCADIA FL HC Unknown Adult (18-64 

years old) Male reported 

Rash developing on 

different parts of skin all 

over his body

12855 7 25-Apr-02 LORSBAN 15G 6271900034 INVER GROVE 

HEIGHTS

MN HC Unknown Adult (18-64 

years old) Male reported 

Dizziness/Vertigo, 

Memory Loss

12875 42 12-Apr-02 ANT-STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 ELYRIA OH HC A 55 year old Male 

reported Seizure
Page 33 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

12875 176 24-Apr-02 HOME DEFENSE 

ORTHO-KLOR 

INSECT & TERMITE 

KILLER

23902513 FARMERSVILL

E

TX HC Unknown Adult (18-64 

years old) Male reported 

No Symptoms Described

12937 7 23-Jan-02 DURSBAN TARMA OH HC A 77 year old Female 

reported Irritation/Pain, 

Headache, 

Dizziness/Vertigo, 

Hypertension

12937 13 29-May-02 LORSBAN (NONSPECIFIC)CORNELIUS OR HC A 56 year old Male 

reported Mental Status 

Changes

12937 14 3-May-02 LORSBAN (NONSPECIFIC)AUSTINVILLE VA HC A 76 year old Male 

reported Nausea, 

Vomiting, Diarrhea

12989 1 2-May-02 CYREN TC 6776000010 MCALLEN TX HC A 2 month old Female 

Child reported 

Drowsiness/Lethargy, 

Respiratory Depression 

and Eyes rolling around 

in Head

13008 17 6-May-02 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 HARTFORD CT HC A 36 year old Male 

reported Diarrhea, 

Vomiting

13008 36 14-May-02 ANT-STOP ANT 

KILLER DUST

23902517 AMARILLO TX HC A 34 year old Male 

reported Shortness of 

Breath

13099 1 28-Jun-02 TERMITE KILL II 138600615 RICHMOND IN HC Unknown Adult (18-64 

years old) Female 

reported Shortness of 

Breath, Bronchospasm

13099 2 16-Jun-02 TERMITE KILL II 138600615 WEST 

ALEXANDRIA

OH HC A 45 year old Female 

reported 

Coughing/Choking , 

Dyspnea , Shortness of 

Breath

13135 5 2-Jun-02 ANT-STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 JACKSONVILL

E

FL HC Unknown Adult (18-64 

years old) Female 

reported Respiratory 

Irritation

13135 17 2-May-02 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 STAFFORD VA HC A 26 year old Female 

reported Headache, 

Fever/hyperthermia, 

Enlarged Tonsils
Page 34 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

13135 50 22-Jun-02 ANT-STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 LEXINGTON KY HC A 57 year old Female 

reported Pruritus, Rash 

on her Neck and 

Shoulders

13135 128 1-Jun-02 ANT-STOP ANT 

KILLER DUST

23902517 THOUSAND 

OAKS

CA HC Unknown Adult (18--64 

years old) Male, 

Symptoms Not 

Mentioned

13243 27 28-Jun-02 ANT STOP ANT

KILLER (TRIGGER 

SPRAY)

23902490 SAYER PA HC Unknown Adult (18-64 

years old) Female 

reported Rash, 

Bullae/Blisters, Pruritus

13241 3 1-Jun-02 SPECTRACIDE 

TERMITE AND ANT 

CONTROL

0627190005

6 008845

BERLIN NJ HC Unknown Adult (18-64 

years old) Female 

reported Tingling in her 

Hands, Muscle Pain in 

Calves and Shoulders, 

Pain in right Eye, Muscle 

Twitching, Nervousness, 

Loss of Appetite, 

Difficulty Sleeping, 

Memory Problems, 

Squeezing feeling in 

Neck, Vibrating inside her 

body, Tingling in Legs 

below Knees and Feet, 

13241 10 19-Jul-02 DURSBAN PRO 6271900166 ID HC A 31 year old Female 

reported 

Dyspnea/Shortness of 

Breath

13281 4 1-Jul-02 LORSBAN-4E 6271900220 AMARILLO TX HC Unknown (2-6 years old) 

Male Child reported a 

young boy drank the 

product and it was in a 

Gatorade bottle in the 

garage or house where 

the boy had access to the 

material.

13281 15 21-Aug-02 DURSBAN TC 6271900047 BIRMINGHAM AL HC Unknown Adult (18-64 

years old) Male reported 

Vomiting, Loss of 

Consciousness
Page 35 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

13331 3 3-Jul-02 DURSBAN LAWN 

INSECT SPRAY

23902633 NAPA ID HC A 59 year old Male 

reported Headache, 

Nausea, 

Drowsiness/Lethargy, 

General Aches and Pains

13331 20 9-Aug-02 ANT STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 OKLAHOMA 

CITY

OK HC A 23 year old Female 

reported Rash on Legs, 

Chest and Neck

13331 28 8-Aug-02 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 HINCKLEY OH HC A 14 year old Female 

reported Rash all over 

her body and today the 

Rash is just on her Joints.

13364 3 24-Sep-02 ORTHO DURSBAN 

LAWN INSECT 

SPRAY

23902633 MARINA CA HD Unknown Adult and 

Children evacuated from 

daycare reported, 

Nausea, Headache and 

Burning Throat from 

fumes; adults had 

Dizziness, Chest 

Pressure.

13386 5 9-Sep-02 DURSBAN TC 6271900047 IN HC Unknown Families (2-64 

years old) All Females 

reported Diarrhea, 

Coughing/Choking, Ear 

Infections, Abdominal 

Pain, and Allergy.

13419 6 1-Jan-02 K-GRO HOME PEST 

INSECT CONTROL

4651500013 GREENSBOR

O

NC HB Unknown Adult (18-64

years old) Families 

reported Headache, 

Other Miscellaneous, 

Daughter has a Seizure

13458 2 27-Jun-02 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 FARMINGTON NM HC Unknown Adult (18-64 

years old) Female 

reported Edema, 

Irritation/Pain, Joint Pain

13458 25 2-Sep-02 FLEA-B-GON 

OUTDOOR FLEA 

AND TICK KILLER

23902423 MARIETTA GA HC Unknown Adult (18-64) 

years old) Male reported 

Dizziness/Vertigo, 

Vomiting
Page 36 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

13509 12 29-Sep-02 DURSBAN PRO 6271900166 CONSHOHOC

KEN

PA HC Unknown Adult (18-64 

years old) Female 

reported Dyspnea, 

Coughing/Choking, 

Congestion

13509 14 14-Sep-02 DURSBAN (NONSPECIFIC)SUNNYVILLE CA HC A 3 year old Female 

Child reported Diarrhea, 

Fever/hyperthermia

13510 10 4-Oct-02 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 TITUSVILLE FL HC A 70 year old Male 

reported Tachycardia, 

Hypertension

13669 13 18-Nov-02 DURSBAN TC 6271900047 WHITTIER CA HC Unknown Adult (18-64 

years old) Male, Female 

reported Byron: Prostate 

Cancer, Bronchial 

Spasms and white spots 

on his Brain.

Laura: Immune deficiency 

of the Liver, Swollen 

Liver, Elevated level of 

Liver Enzymes, Mark: 

Elevated level of Liver 

Enzymes

13829 14 22-Feb-03 RAID FIRE ANT 

KILLER FORMULA 2

482200264 RICHARDSON TX HC A 59 year old Female 

reported Dermal 

Irritation/Pain, Oral 

Irritation, Dyspnea, 

Throat Irritation, Nausea, 

Headache, Tingling, 

Edema, Bad Taste, Nasal 

Irritation, Back Pain

13945 1 5-Mar-03 CYREN TC 6776000010 JUPITER FL HC Unknown Adult (18-64 

years old) Male reported 

Burning Skin, Dry Mouth, 

Numbness of Lips and 

Tremors.

13959 26 25-Mar-03 ANT STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 CALDWELL ID HC Unknown Adult (18-64 

years old) Female 

reported Respiratory 

Irritation, Congestion
Page 37 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

14093 14 18-May-03 LORSBAN-4E 6271900220 TX HD Unknown Age Family 

reported Product being 

sprayed and says that 

husband, 2 kids and self 

were outside and wind 

picked up and blew 

product on them. She 

and 1 child never had 

symptoms. Today 1 child 

is having Diarrhea and 

husband was it with 

Pneumonia and has 

Rash on his back. 

14178 15 2-Jul-03 LORSBAN 4E 

INSECTICIDE

6271900220 MINOT ND HC Unknown Adult (18-64 

years old) Male reported 

Burning Eyes, Some 

Shakiness of Hands.

14190 19 20-Jun-03 SPECTRACIDE 

CARPENTER ANT & 

TERMITE KILLER 

INSECT SPRAY 

CONCENTRATE

0465150005

1 008845

HINSDALE IL HC A 72 year old Male 

reported 

Fever/hyperthermia, 

Nausea, Muscle Cramps, 

Aches, Tremors, 

Shaking, Vomiting

14190 27 24-Jun-03 SPECTRACIDE 

DURSBAN MULTIPURPOSE INSECT 

SPRAY 

CONCENTRATE

884500030 HUDSON FL HC Unknown Adult (18-64 

years old) Male reported 

Chest Pain, 

Dizziness/Vertigo, 

Dypsnea

14198 21 27-Jun-03 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 LONG ISLAND NY HC A 47 year old Female 

reported Wheezing, 

Diarrhea

14198 22 26-Jun-03 ORTHO-KLOR ANT 

KILLER DUST

23902517 STUART 

TOWN

PA HC A 11 year old Male 

reported Throat Irritation

14198 73 22-Jun-03 ANT STOP ANT 

KILLER DUST 

(DISCONTINUED)

23902517 APACHE 

JUNCTION

AZ HC Unknown Adult (18-64 

years old) Female 

reported Dermal 

Irritation/Pain, Rash

14219 1 30-May-03 CYREN 2E 6776000006 CLAIREMOOR

E

OK HC A 55 year old Male 

reported Pneumonia

14339 1 1-Jun-03 CHLORPYRIFOS 

PRO 2

AZ HE Unknown Adult (18-64 

years old) Male No 

Symptoms Mentioned
Page 38 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

14317 45 17-Jul-03 ANT STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 CENTER 

POINT

TX HC A 88 year old Male 

reported Nausea, Weight 

Loss

14419 6 17-Aug-03 CHLORPYRIFOS 

(UKN PRODUCT)

CLIFTON TX HB Unknown Adult (18-64 

years old) Male reported 

Stopped Breathing and 

Convulsions

14428 24 2-Aug-03 DURSBAN LAWN 

INSECT SPRAY 

(CONCENTRATE)

23902633 ATLANTA GA HC A 39 year old Female 

reported Respiratory 

Irritation, Abdominal Pain, 

Diarrhea, Headache, 

Coughing/Choking

14568 1 23-Sep-03 DURSBAN TC 6271900047 CA HB A 46 year old Male 

reported Nystagmus, 

Dizziness/Vertigo, 

Inflamed Sinus

14697 2 1-Oct-03 ANT STOP KILLER 

DUST 

(DISCONTINUED 

FORMULA)

23902517 TERRENCE CA HC A 39 year old Female 

reported Muscle Spasms

14719 7 23-Jun-03 LORSBAN-4E 6271900220 ND HC Unknown Adult (18-64 

years old) Male reported 

Lost sense of Taste, 

Insomnia, Depression

14737 5 21-Dec-03 REAL KILL FIRE ANT 

KILLER GRANULES

0495850001

6 000478

JACKSONVILL

E

FL HC Unknown Adult (18-64 

years old) Male reported 

Coughing/Choking, 

Fever/hyperthermia

14959 2 25-Apr-03 DURSBAN 2E 6271900065 MI HB Unknown Age Male Child 

accidentally drank an 

unmarked container and 

left it on child 

grandmother’s porch. The 

Child was playing on the 

porch, picked up the 

bottle, and drank the 

product. Child suffered 

severe and permanent 

injuries and damages.

14959 6 4-Aug-03 LORSBAN PRIOR LAKE MN HC A 66 year old Male 

reported Rash on his 

Legs
Page 39 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

15031 2 19-Aug-03 LORSBAN CALEDONIA MN HC A Male (40 year old) 

Female (39 year old) 

Male Child (15 year old) 

reported Headache, 

Severe Stomach Ache, 

Cramping, Diarrhea, and 

Difficulty sleeping during 

the night of alleged 

exposure.

15148 18 17-May-04 DURSBAN TC 6271900047 PONCA CITY OK HC A 51 year old Female 

reported Headache, 

Dizziness/Vertigo, 

Respiratory/Irritation, 

Malaise, Confusion

15207 47 21-May-04 ANT STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 NJ HC A 33 year old Male 

reported Vomiting, 

Diaphoresis, Joint Pain

15207 58 25-May-04 OUTDOOR ANT, 

FLEA AND CRICKET 

SPRAY

23902423 LA HC Unknown Adult (18-64 

years old) Female 

reported Rash all over 

her body

15401 4 19-Jun-04 SPECTRACIDE 

CARPENTER ANT & 

TERMITE KILLER 

INSECT SPRAY 

CONCENTRATE

0465150005

1 008845

WICHITA 

FALLS

TX HC A 48 year old Female 

reported Irritation/Pain, 

Other Miscellaneous

15419 112 7-Jul-04 ORTHO-KLOR 

INSECT AND 

TERMITE KILLER

23902513 TUCSON AZ HC Unknown Adult (18-64 

years old) Female 

reported No Symptoms 

Mentioned
Page 40 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

15453 2 2-Dec-02 DURSBAN TC 6271900047 WEST 

LAFAYETTE

IN HB A Family Age Unknown 

The mother and children 

reported Rhinorrhea, 

Increased Mucus 

Production, Drooling, 

Nausea, Vomiting, and 

Diarrhea. The father had 

minimal symptoms. They 

also claim to have had 

Headaches, Mood 

Disturbance, Tension, 

Focus and Learning 

Problems, Increased 

Fatigue with Muscle 

Weakness and 

Sleepiness. 

15453 11 5-Aug-04 LORSBAN-4E 6271900220 GREAT FALLS MT HC A 54 year old Male 

reported Myalgia, Joint 

Pain, Headache

15453 18 27-Aug-04 DURSBAN PRO 6271900166 NATIONALCY CA HC A 42 year old Male 

reported 

Coughing/Choking, 

Anorexia, Diarrhea

15419 528 17-Jun-04 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 TN HC Unknown Adult (18-64 

years old) Male reported 

Rash on his Stomach

15483 5 1-Aug-04 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 ROCHESTER MI HC A 48 year old Male 

reported Nausea, 

Dizziness/Vertigo

15507 1 27-Jul-04 DRAGON HOME 

PEST KILLER

1600139 HUTCHINSON KS HC A 53 year old Female 

reported Headache, 

Breathing Problems, 

Dizziness/Vertigo

15519 8 17-Aug-04 DURA GUARD ME 

MICROENCAPSULA

TED INSECTICIDE

49900367 ST CHARLES MO HC Unknown Adult (18-64 

years old) Female 

reported Rash

15602 29 16-Sep-04 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

CONC

23902513 CA HC A 58 year old Male 

reported Nausea, 

Tremor, Vomiting
Page 41 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

15637 1 3-Nov-04 SURRENDER TC BRADENTON FL HB Unknown Adult (18-64 

years old) Female 

reported Blood Pressure 

Elevated, Muscle 

Weakness, Headache, 

Swelling, Diarrhea, 

Nausea, Blurred Vision

15669 4 1-Aug-02 DURSBAN NONSPECIFICTULSA OK HC Unknown Adult (18-64 

years old) Female 

reported Health 

Problems, Mastectomy, 

Possible Constipation

15784 10 9-Nov-04 ORTHO ANT STOP 

TRIGGER SPRAY 

(MEXICO)

23902517 FL HC A 63 year old Male 

reported Rash on Under 

arms, Legs, Stomach, 

Back, Head and Arms

15837 4 1-Jan-04 CHLORPYRIFOS GRANITE CITY IL HB Unknown Adult (18-64 

years old) Male reported 

No Symptoms Described

16009 4 9-Feb-05 LORSBAN 15G 

GRANULAR 

INSECTICIDE

6271900034 MARYSVILLE CA HC A 45 year old Female 

reported Diaphoresis, 

Vomiting, Other 

Miscellaneous

16126 15 12-Mar-05 ANT STOP ANT 

KILLER (TRIGGER 

SPRAY)

23902490 MINNEAPOLIS MN HC A 81 year old Male 

reported Shortness of 

Breath

16352 35 17-May-05 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 TULSA OK HC A 35 year old Male 

reported 

Dizziness/Vertigo, 

Vomiting

16396 62 23-Jun-05 ANT STOP ANT 

KILLER DUST 

(DISCONTINUED)

23902517 GRAND 

JUNCTION

CO HC A 3 year old Male Child 

reported Abdominal Pain, 

Vomiting

16633 6 5-Aug-05 DURSBAN TC 

TERMITICIDE 

CONCENTRATE

6271900047 BIRMINGHAM AL HC Unknown Adult (18-64 

years old) Male reported 

Nausea, Throat Irritation, 

Vomiting
Page 42 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

16633 10 14-Aug-05 DURSBAN PRO 

INSECTICIDE

6271900166 BOAZ AL HC Unknown Adult (18-64 

years old) Male reported 

Bradycardia, Diaphoresis, 

Agitated/Irritable, 

Confusion, Other 

Miscellaneous

16652 64 27-Aug-05 HOMEDEFENSE 

INDOOR AND 

OUTDOOR INSECT 

KILLER 1

23902490 ROMEOVILLE IL HC A 32 year old Female 

reported Vomiting, 

Diarrhea, Chest Pain

16689 26 27-Aug-05 DURSBAN -

OTHER/UNKNOWN

PHILADELPHI

A

PA HC A 63 year old Male 

reported Irritation/Pain, 

Pruritus, Other 

Miscellaneous

16738 8 9-Feb-05 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 YUBA CITY CA HC Unknown Adult (18-64 

years old) Female 

reported, Vomiting, 

Headache, Dyspnea

16754 28 20-Sep-05 RID-A-BUG FLEA 

AND TICK KILLER 

LIQUID

884500031 FAIRBURY NE HC A 34 year old Female 

reported Hives/Welts, 

Pruritus, Rash

16763 1 7-Oct-05 LORSBAN* 75WG 0627190030

1 010163

OXNARD CA HC (6) Male Trucking 

Company Employees 

reported Burning Eyes, 

Nausea, Tremors

16890 8 8-Oct-05 DISC ZODIAC 

FLEATROL YARD 

AND KENNEL 

SPRAY

272400327 TX HC A 55 year old Male 

reported Stomach 

Swelling

16940 33 19-Aug-05 CHLORPYRIFOS 4E 

AG

6622200019 CA HC (10) Field Workers 

employees reported 

Headache, Vomiting, 

Nausea, Shortness of 

Breath, Dizziness, Stuffy 

Nose and Pressure on 

the Chest. The 

employees were indoors 

working under 

evaporative coolers. Two 

additional employees had 

symptoms of Headache 

and Vomiting when they 

started working in the box 

yard.
Page 43 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

16940 45 1-Nov-05 DURSBAN PRO 6271900166 MERCED CA HC Unknown Adult (18-64 

years old) Male and 

Female reported (5) 

Individuals Employees 

had short term Symptoms 

of Itchy and Burning Eyes 

and Nausea. 

17056 2 1-Oct-03 DURSBAN TC 

TERMITICIDE 

CONCENTRATE

6271900047 REEBLEY CA HC A 6 year old Male Child 

reported Abdominal Pain, 

Other Miscellaneous

17300 3 1-Jun-05 DURSBAN R 6271900044 WILLOUGHBY, 

MAYFIELD 

HTS

OH HB A 45 year old Female 

reported Numbness, 

Difficulty Swallowing, 

Shortness of Breath

17298 34 24-Apr-06 ANT KILLER SANTA ANA CA HC A 4 year old Male Child 

reported the child 

grandmother had put 

some ant killer in a water 

bottle. The child drank 

from the bottle and 

started to have breathing 

difficulty and experienced 

stomach ache, The child 

was taken to a hospital 

and was hospitalized.

17581 1 28-Jun-06 MOSQUITOMIST 

TWO ULV

832900018 LAMONT IL HC A 39 year old Female 

reported Shortness of 

Breath, Headache, 

Memory Problems, 

Erythema/Flushed, 

Dermal Irritation/Pain, 

Tremor

17585 6 6-Jun-06 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 MAZOMANIE WI HC A 57 year old Male 

reported Nausea, 

Malaise, Ocular 

Irritation/Pain

17701 6 14-Jul-06 SPECTRACIDE 

TERMITE & ANT 

CONTROL 

CONCENTRATE

0627190005

6 008845

BATON 

ROUGE

LA HC A 21 year old Male 

reported Diaphoresis, 

Fasciculation, 

Hallucinations, Delusion

17837 4 29-Jun-06 DURSBAN PRO 

INSECTICIDE

6271900166 KNOXVILLE TN HC Unknown Adult (18-64 

years old) Male reported 

Hives/Welts, Rash, 

Throat Irritation, 

Drowsiness/Lethargy, 

Headache
Page 44 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

17837 5 29-Jul-06 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 WOODLAKE MN HC A 48 Year old Male 

reported Malaise, 

Dizziness/Vertigo, 

Fever/hyperthermia

17837 9 7-Aug-06 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 GROVE OAK AL HC Unknown Adult (18-64 

years old) Male reported 

Diarrhea

17863 32 15-Aug-06 DURSBAN LAWN 

INSECT SPRAY 

(CONCENTRATE)

23902633 BAKERSFIELD CA HC A 18 year old Male 

reported Vomiting

18233 1 1-Jun-06 MOSQUITOMIST 

ONE U.L.V.

832900024 AURORA MO HA A 58 year old male was 

reportedly exposed to a 

ULV product five to six 

times. Each time he was 

taken to the emergency 

room with difficulty 

breathing and an upset 

stomach. He was 

diagnosed with and 

treated for COPD. The 

last time he was exposed 

to the ULV product, he 

fell while taking a shower 

after the exposure. He 

was subsequently 

hospitalized and died 

about 10 days later. He 

also suffered from 

peeling skin.

18287 1 23-Jul-06 MOSQUITOMIST 

ONE ULV

832900024 AURORA MO HB A 7 year old Male 

reported severe Asthma

18428 55 24-Mar-07 LORSBAN SANTA PAULA CA HC A 6 year old Male Child 

reported has been 

hospitalized after 

ingesting an unmarked 

water bottle the father 

used for Ant Control. The 

child started to foam at 

the mouth and became 

unconscious. No 

Symptoms mentioned.

18599 56 26-May-07 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 FLEMINGTON NJ HC A 45 year old Male 

reported Shortness of 

Breath, Respiratory 

Irritation
Page 45 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

18732 3 31-May-07 DURSBAN LAWN 

INSECT SPRAY 

(CONCENTRATE)

23902633 FL HC Unknown Adult (18-64 

years old) Male reported 

Dizziness, Diarrhea

18732 7 1-Jun-07 DURSBAN READYSPRAY OUTDOOR 

FLEA AND TICK 

KILLER 1 (HOSEEND SPRAYER)

23902633 FL HC Unknown Adult (18-64 

years old) Male reported 

Dizziness, Vomiting, 

Nausea

18732 16 31-May-07 DURSBAN LAWN 

AND GARDEN 

INSECT CONTROL 

(GRANULES)

23902570 CA HC Unknown Adult (18-64 

years old) Male reported 

Dermal Irritation, Other 

Neurological - Drooping 

Lip

18732 36 7-Jun-07 DURSBAN LAWN 

INSECT SPRAY 

(CONCENTRATE)

23902633 VA HC Unknown Adult (18-64 

years old) Male reported 

Hives/Welts, Pruritus

18759 1 2-Jul-05 MOSQUITOMIST 

TWO ULV

832900018 WAYNE IL HB Unknown Adult (18-64 

years old) Female 

reported Aneurism, No 

Symptoms Mentioned

18839 2 11-Jul-07 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 FIREBAUGH CA HC A 28 year old Male 

reported Nausea, 

Dyspnea, Shortness of 

Breath

18913 1 25-Aug-07 MOSQUITOMIST 

TWO U.L.V.

832900018 GILBERT IL HC A 69 year old Female 

reported Diarrhea, 

Tremor, Lacrimation, and 

Other Renal - Urinary 

Frequency.

18930 19 23-Dec-06 DURSBAN TC 

TERMITICIDE 

CONCENTRATE

6271900047 CHARLOTTE NC HC Unknown Adult (18-64 

years old) Female 

reported Nausea, 

Diarrhea, Arthralgia, 

Drowsiness/Lethargy, 

Headache, Muscle 

Weakness, Blurred 

Vision, Nasal Discharge, 

Nasal Irritation, and 

Respiratory Irritation.

18930 33 23-Apr-07 LORSBAN 15G 

GRANULAR 

INSECTICIDE

6271900034 OREGON IL HC A 68 year old Male 

reported Respiratory -

Dyspnea/Shortness of 

Breath

18930 46 1-Oct-06 DURSBAN 

(UNSPECIFIED)

WALKERTOW

N

NC HB A 43 year old Male 

reported Dermatological 
Page 46 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

Rash

18966 2 17-Aug-07 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 STOCKTON CA HC A 67 year old Male 

reported Neurological 

Headache

18984 21 10-Jul-07 LORSBAN-4E 6271900220 CA HE Field Farmworkers 

reported ill, No 

Symptoms Mentioned.

19025 6 3-Sep-07 ANT STOP ANT 

KILLER DUST (DC'D 

CHLORPYRIFOS 

FORMULA)

23902517 OH HC Unknown Adult (18-64 

years old) Female 

reported Blurred Vision, 

Visual Defect

19218 20 22-Nov-07 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 FL HC A 81 year old Male 

reported Dermal Irritation, 

Pruritus

19218 23 25-Nov-07 ORTHO-KLOR ANT 

KILLER DUST

23902517 CHICAGO IL HC A 3 year old Female 

Child reported Abdominal 

Pain, Vomiting, Diarrhea

19293 2 18-Dec-07 DURSBAN -

OTHER/UNKNOWN 

PRODUCT

PAOLI IN HC A 52 year old Male 

reported Confusion, 

Nausea, High Blood 

Pressure, Shaking, 

Muscle Tightness, Throat 

Irritation

19499 1 17-Feb-08 SPECTRACIDE 

CARPENTER ANT & 

TERMITE KILLER 

INSECT SPRAY 

CONCENTRATE

0465150005

1 008845

HILLSBORO OH HC A 63 year old Male 

reported 

Coughing/Choking, 

Erythema/Flushed, 

Irritation/Pain, Blistering 

on Face, Pruritus, 

Irritated Breathing

19681 164 21-Mar-08 ORTHO-KLOR ANT 

KILLER DUST

23902517 CA HC A 52 year old Female 

reported Oral Irritation, 

Rash, Seizure, 

Confusion, Agitated, 

Pruritus
Page 47 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

19758 6 1-May-08 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER

23902513 WINDSOR 

LOCKS

CT HC A four year old male was 

playing in an area that 

was treated with the 

product 4 hours earlier. 

He broke out in a diffuse 

rash. He was given a 

bath and Benadryl. The 

symptoms did not clear 

so he was taken to the 

ER. It could not be 

determined if the rash 

was from the product or 

antibiotics that the child 

had been taking. He 

discontinued the 

antibiotics and was given 

steroids. 

19742 1 27-May-08 NUFOS 4E 6776000028 CA HC Unknown age adult male 

reported product sprayed 

back into his face by wind 

for approximately one 

hour. He was not wearing 

appropriate PPE. He 

experienced nausea, 

vomiting, difficulty 

breathing and felt as if his 

throat was closing.

19758 65 27-May-08 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 FL HC Unknown age (18-64 

years old) female 

developed headache, 

dermal irritation (within 12 

hours) and a cold (within 

24 hours) after her 

husband empty three 

bottles of product around 

the house. She saw an 

MD who prescribed 

antibiotics. The husband 

developed a headache

and dermal irritation 

(within 12 hours).
Page 48 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

19837 17 6-Jun-08 SPECTRACIDE 

CARPENTER ANT & 

TERMITE KILLER 

INSECT SPRAY 

CONCENTRATE

0465150005

1 008845

SELMA AL HC Unknown age adult 

female applied product in 

yard. Next day she 

developed fever, tongue 

irritation, fever, pain, 

rash, throat irritation, and 

vomiting. She was weak 

and fell and hit her head. 

She was hospitalized and 

given antibiotics, 

breathing treatments, and 

steroids. She has a 

history of COPD, 

emphysema and 

hypertension.

20065 4 26-Jun-08 DURSBAN PRO 

INSECTICIDE

6271900166 LAKE GENVA WI HC 42 year old male 

professional applicator 

was working with product 

for 3 hours without using 

PPE. He experienced 

tingling and numbness in 

his arms, back and head 

and tachycardia. He went 

to ED and was cleaned in 

the shower. CBC, RBC 

and plasma 

cholinesterase levels 

were done. No SLUDGE 

symptoms were 

experienced. CXR 

performed. 

20065 9 16-Jul-08 LORSBAN 4E 6271900023 ECHO MN HC 56 year old male was 

flattening pesticide 

boxes, picking up 

container lids and labels 

to be recycled and was 

not wearing PPE. There 

was some minor amount 

of liquid left in materials. 

After about one hour, he 

experienced a rash on his 

wrist. Later he felt 

nauseated, had no 

appetite, the left side of 

his face swelled and the 

rash spread up his arm. 

He went to the hospital. 

He was given blood work 

some medication and 

released. 
Page 49 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

20725 40 6-Oct-08 REAL-KILL 

DURSBAN

0096880009

5 000478

OXNARD CA HC Five year old male 

ingested unknown 

amount of product. He 

was taken to the hospital, 

treated and released 13 

hours later. The only 

symptom reported was 

sore throat.

21148 9 1-Jan-09 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 MAQUOKATA IA HC A 31 year old male 

applied the product two 

times a year for about 1 

to 2 weeks at a time in a 

cemetery using a 

groundboom. He did not 

use PPE and did not 

wash product off until the 

end of the day. He 

suffered from shortness 

of breath, abdominal 

cramping, and now has 

allergies. 

20997 49 13-Jun-09 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 IL HC A 48 year old male 

applied product in his 

garage. He experienced 

tremors and dizziness. 

He saw his physician who 

did not run any tests or 

prescribe and 

medications.

20997 52 15-Jun-09 ORTHO-KLOR SOIL 

INSECT AND 

TERMITE KILLER 

(CONCENTRATE)

23902513 BROADVIEW IL HC 58 year old male applied 

product in his garage 

over the weekend. 

Monday he worked in the 

garage. Tuesday he 

experienced dizziness 

and nausea and 

Wednesday he saw his 

physician. By the 

following Tuesday he was 

feeling better.

21209 8 1-Jul-09 LORSBAN-4E 

INSECTICIDE (NAF163)

6271900220 NORWALK CT HC An 81 year old female 

applied product in 

backyard. In an unknown 

amount of time later she 

experienced shortness of 

breath and 

cough/choking. She saw 

an MD and was 

prescribed an inhaler.
Page 50 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

21092 62 10-Jul-09 ANT STOP ANT 

KILLER DUST (DISC 

CHLORPYRIFOS)

23902517 SILVER 

SPRING

MD HC An 84 year old female 

was exposed to a product 

she applied 2 to 3 years 

ago when she lifted up a 

board in her yard. She 

experienced lesions on 

her arms. She saw her 

physician.

21181 17 24-Aug-09 HOT SHOT 

MAXATTRAX 

ROACH BAIT

0096880006

7 008845

ROCKPORT TX HC Adult postpartum female 

experienced a fever, 

chills vomiting and could 

smell poison on her hand. 

She put a bait product in 

the cupboard in the 

morning.

22051 1 24-May-10 WARHAWK 3470400857 SOUTH 

GLASTONBUR

Y

CT HC A 67 year old male's 

home is located 25 feet 

from five rows of trees 

that were sprayed with 

the product. The doors 

and windows were open 

and the caller was home 

at the time of application. 

The caller detected a 

chemical odor and one 

and a half to two hours 

later he developed a 

headache, ocular 

irritation, numbness in his 

cheek, vomiting, lower 

back aches, throat 

irritation, and weakness. 

He saw an MD and was 

given an unknown 

injection and the MD said 

he had signs of chemical 

poisoning. Symptoms 

persisted more than six 

days.
Page 51 of 51

Main IDS Report 

Chemical: Chlorpyrifos (PC code 059101) Human Incidents

Incident 

Number

Incident 

Date Product Name

Registration 

Number City State

Exposure 

Type* Incident Description

22005 53 26-May-10 DURSBAN LAWN 

INSECT SPRAY 

(CONCENTRATE)

23902633 OH HC Unknown age (18-64) 

adult male spilled the 

product on his hand and 

wrists. He rinsed it off 

about an hour later. The 

next day he has hives 

and a rash in those 

areas. He went to a 

health care facility and 

his MD gave him a 

cortisone shot and a 

prescription salve to 

apply. His symptoms 

lasted three days.