UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

MEMORANDUM 

Date: August 29, 2013 

SUBJECT: Dazomet: Review of Human Incidents 

PC Code: 035602 

Decision No.: 476790 

Petition No.: NA 

DP Barcode: 0414491 

Registration No.: NA 

Regulatory Action: NA 

Risk Assessment Type: NA Case No.: NA 

TXRNo.:NA CAS No.: 533-74-4 

MRIONo.: NA 40CFR: NA 

FROM: nna Recore, Industrial Hygienist 

Toxicology and Epidemiology Branch 

Health Effects Division (7509P) 

and 

Elizabeth Evans, Environmental Protection Specialist 

Toxicology and Epidemiology Branch 

Health Effects Division (7509P) 

THROUGH: -6.----

To

David 

Health 

xicology 

J. 

Effects 

Mille

and 

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Division 

, 

Epidemiology 

Acting Branch 

(7509P) 

Branch 

Chief ~ ~ 

TO: Shalu Shelat, Risk Assessor 

Risk Assessment Branch VI 

Health Effects Division (7509P) 

and 

Dana Friedman, Chemical Review Manager 

Risk Management & Implementation Branch 2 

Pesticide Re-evaluation Division (7508P) 

Summary and Conclusions 

Ver.Apr.08 

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

NIOSH 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 analysis will be included in the risk assessment. 

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The Agricultural Health Study (AHS) is also a potential source of information associated with 

human health effects associated with certain pesticides. Dazomet is not included in the AHS, 

and therefore this study does not provide information for this report. 

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 

Dazomet is a non-selective soil fumigant with fungicidal, herbicidal and nematicidal properties. 

When dazomet is applied, it is quickly broken down into several degradates; the major degradate 

being methyl isothiocyanate (MITC). MITC is highly volatile and is responsible for the fumigant 

properties of dazomet. Dazomet is used on a wide range of sites including golf greens or tees, 

nonbearing crops, turf sites, ornamental sites, field nurseries, compost piles, potting soils, and 

strawberries and tomatoes (in California only). There are no residential uses of dazomet. 

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

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

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

consulted for pesticide incident data on the active ingredient dazomet (PC Code: 035602). The 

purpose of the database search is to identify potential patterns in the frequency and severity of 

the health effects attributed to dazomet exposure. 

In addition, findings from the Agricultural Health Study (AHS) were reviewed. The AHS is a 

high quality, prospective epidemiology study evaluating the link between pesticide use and 

various health outcomes including cancer. Dazomet 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) 

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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 

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 specific. 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 

pesticide 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 February 19,2013, there was I incident reported in 

the database. This incident is classified as moderate severity. Overall, there are few incidents 

involving dazomet reported to IDS. 

In Aggregate IDS, from January 1, 2008 to February 19, 2013, there were 7 reported incidents 

involving dazomet. These incidents are classified as minor severity. 

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 non-occupational 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 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. 

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A query of SENSOR-Pesticides 1998-2009 identifies 2 cases, stemming from 2 events, involving 

dazomet. Both cases involve a single active ingredient. One case occurred in California in 1999, 

and was moderate in severity. No case narrative was entered. The second case occurred in 

California in 2005 and was low in severity. This case applied product to a telephone pole to 

control for termites and developed a rash. Both cases were work-related. 

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 formulation/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. 

Dazomet 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 dazomet in both IDS and 

NIOSH 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 analysis will be included in the risk assessment. 

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