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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460

OFFICE OF CHEMICAL SAFETY AND 

POLLUTION PREVENTION

MEMORANDUM

Date: November 122013

SUBJECT: Aminopyralid: Tier I Review of Human Incidents

PC Code: 005100, 005219,{)05209

Decision No.:482282

Petition No.: NA

Risk Assessment Type: NA

TXRNo.:NA 

MRIDNo.:NA

DP Barcode: 04 1 5939

Registration No.:NA 

Regulatory Action: NA 

Case No.: NA

CAS No.: 1501 1 4-71 -9, 566191-87-5

40 CFR: NA

Ver.Apr.08

FROM: Shanna Recore, Industrial Hygienist !}, "

Toxicology and Epidemiology Branch

Health Effect Division (7509P)

and

JJ. n 0,."" nl?

Elizabeth Evans, Environmental Protection Specialist

Toxicology and Epidemiology Branch

Health Effects Division (7509P) /)

THROUGH: David Miller, Acting Branch Chie 

Toxicology and Epidemiology Branch 

Health Effects Division (7509P)

11

/O/IJ

TO: Douglas Dotson, Risk Assessor 

Risk Assessment Branch II 

Health Effects Division (7509P)

and

Katie Weyrauch,Chemical Review Manager

Risk Management & Implementation Branch 5

Pesticide Re-evaluation Division (7508P) 

Summary and Conclusions

Based on the low frequency and severity of incident -cases reported for aminopyralid, there does 

not appear to be a concern at this time that would warrant further investigation. The Agency will 

continue to monitor the incident information and if a concern is triggered, additional analysis

will be included in the risk assessment.
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Detailed Review

I. ACTION REQUESTED

This review is intended to fulfill our requirement to docket summaries of incident data that were 

reported to the Agency, as well as to ensure human incident data and the Agricultural Health 

Study (AHS) are part of the problem formulation phase of registration review. Reports of 

adverse health effects allegedly due to a specific pesticide exposure (i.e., an "incident") are 

largely self-reported and therefore, generally speaking, neither exposure to a pesticide or 

reported symptom (or the connection between the two) is validated or otherwise confirmed. 

Typically, causation cannot be determined based on incident data. However, incident

information can be an important source of feedback to the Agency: incidents of severe outcome,

or a suggested pattern or trend among less severe incidents, can signal the Agency to further 

investigate a particular chemical or product. Observational epidemiology studies relate the risk 

of disease, e.g., cancer, and exposure to an agent such as a pesticide product in the general 

population or specific sub-groups like pesticide applicators.

II. BACKGROUND

Aminopyralid is a new pyridine carboxylic acid herbicide intended for use in rangeland, 

permanent grass pastures, non-cropland areas (rights-of-way, roadsides and non-irrigation ditch 

banks), natural areas (wildlife management areas, natural recreation areas, campgrounds, 

trailheads, and trails), and grazed areas in and around these sites, as well as wheat. Aminopyralid 

provides systemic postemergence broad-spectrum control of a number of key noxious and 

inyasive annual, biennial and perennial weed species, as well as agronomic broadleaf weeds. 

Aminopyralid can also provide residual weed control activity controlling re-infestations and

reducing the need for re-treatment depending on the rate applied and the target weeds. 1

For this evaluation, both the OPP Incident Data System (IDS) and the Centers for Disease 

Control and Prevention/National Institute for Occupational Safety and Health (CDC/NIOSH) 

Sentinel Event Notification System for Occupational Risk-Pesticides (SENSOR) databases were 

consulted for pesticide incident data on the active ingredient Aminopyralid (PC codes: 005100,

00519, 005209). The purpose of the database search is to identify potential patterns in the 

frequency and severity of the health effects attributed to Aminopyralid exposure. Aminopyralid 

is not included in the AHS, and therefore this study does not provide information for this report.

III. RESULTS/DISCUSSION

a. IDS (Incident Data System)

OPP's IDS includes reports of alleged human health incidents from various sources, including 

mandatory Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) Section 6(a)(2) reports 

from registrants, other federal and state health and environmental agencies, and individual 

consumers. Since 1992, OPP has compiled these reports in IDS. IDS contains reports from 

across the U.S. and most incidents have all relevant product information recorded. Reports

1

Excerpt from Aminopyralid Factsheet,found online at:

http://www.epa. gov/oppOOOO1/chem search/reg actions/registration!fs PC-005 l00 1 0-Aug-05.pdf
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submitted to the IDS represent anecdotal reports or allegations only, unless otherwise stated in 

the report.

IDS records incidents in one of two modules: Main IDS and Aggregate IDS:

o Main IDS contains incidents resulting in higher severity outcomes and provides 

more detail with regard to case specifics. This system stores incident data for 

death, major and moderate incidents, and it includes information about the 

location, date and nature of the incident. Main IDS incidents involving only one 

active ingredient (as opposed to pesticide products with multiple active 

ingredients) are considered to provide more certain information about the 

potential effects of exposure from the pesticide.

o Aggregate IDS contains incidents resulting in less severe human incidents (minor, 

unknown, or no effects outcomes). These are reported by registrants only as

counts in what are aggregate summaries.

For the Main IDS, from January 1, 2008 to September 11,2013, there were 3 incidents reported 

for single chemical only in the database. There were 11 additional incidents reported involving 

more than one chemical? There was one fatality that was determined to be not due to pesticides. 3

The other incidents reported were classified as moderate severity. Overall, there are few 

incidents involving aminopyralid reported to IDS.

In Aggregate IDS, from January 1, 2008 to September 11, 2013, there were 35 reported incidents 

involving aminopyralid.

b. SENSOR-Pesticides

The SENSOR-Pesticides database covers 11 states from 1998-2009, although reporting varies 

from state to state. Cases of pesticide-related illnesses are ascertained from a variety of sources, 

including: reports from local Poison Control Centers, state Department of Labor workers' 

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

and physician reports to state Departments of Health. Although both occupational and nonoccupational incidents are included in the database, SENSOR-Pesticides focuses on occupational 

pesticide incidents, and is of particular value in providing that information. The state coordinator 

at each of the 11 respective state Departments of Health conducts case follow- up activities such

as obtaining medical records to verify symptoms and severity. Using standardized protocol and

case definitions derived from poison center reporting, the state SENSOR-Pesticide coordinator 

enters the incident information into the state-based system which is sent to NIOSH annually to be

aggregated.

2 There was also one incident that occurred in Brazil. Foreign incidents are not reviewed in detail because of the 

potential differences in the exposure patterns, use practices, and product formulation.

3 An adult male was alone while applying Milestone from an all terrain vehicle (ATV). While attempting a turn on a 

hill, the ATV rolled on top of him and pinned him.The Sheriff -Coroner Postmortem Examination stated the cause 

of death to be Mechanical Asphyxia and pesticides were not involved.
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A query of SENSOR-Pesticides 1998-2009 finds two cases involving aminopyralid. Both cases 

involved multiple active ingredients. Both cases were low in severity.

One case is described as follows: A 54 year old male walked from his car to his home, he 

smelled pesticide and saw his neighbor spraying herbicide with a tractor and boom 

approximately 400 feet away. As an asthmatic he was concerned for himself and family. 

WSDA was contacted and provided pesticide information on what was sprayed, but did not 

investigate as resident wanted to communicate with applicator. Resident developed upper 

respiratory irritation, but did not seek medical care.

The second case is described as "Exposed while mixing and helping to apply herbicides, 

unknown how exposed." This case reported dermal, respiratory, nervous system and 

gastrointestinal symptoms but was low in severity.

c. Agricultural Health Study (AHS)

The AHS is a high quality, prospective epidemiology study evaluating the link between pesticide 

use and various health outcomes including cancer. The AHS includes private and commercial 

pesticide applicators and their spouses. If there are AHS findings relevant to a particular

pesticide going through registration review, the Agency will ensure they are considered in the 

problem fonnulation/scoping phase of the process and, if appropriate, fully reviewed in the risk 

assessment phase of the process. The AHS includes information on use of 50 different pesticide 

active ingredients commonly used in agriculture. Aminopyralid is not included in the AHS, and

therefore this study does not provide information for this report.

IV. CONCLUSION

Based on the low frequency and severity of incident cases reported for aminopyralid in both IDS 

and SENSOR-Pesticides, there does not appear to be a concern at this time that would warrant 

further investigation. The Agency will continue to monitor the incident information and if a 

concern is triggered, additional anal ysis will be included in the risk assessment.