UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

OFFICE OF CHEMICAL SAFETY AND 

POLLUTION PREVENTION 

MEMORANDUM 

Date: May 8, 2013 

SUBJECT: Ethylene Oxide (ETO): Review of Human Incidents 

PC Code: 042301 DP Barcode: D411127 

Decision No.: 471088 

Petition No.: NA 

Registr ation No.: NA 

Regulatory Action: NA 

Risk Assessment Type: NA Case No.: NA 

TXR No.:NA CAS No.: 75-21-8 

MRID No.: NA 40 CFR: NA 

FROM: Shanna Recore, Industrial Hygienist 

Toxicology and Epidemiology Branch 

Health Effects Division (7509P) 

and 

Elizabeth Evans, Environmental Protection Specialist 

Toxicology and Epidemiology Branch 

Ver.Apr.08 

Health Effects Division (7509P) 

(), ) rn /JJ 68 ... fl181 · 'LcJ,3 THROUGH: David J. Miller, Acting Branch Chief 1 /If~ 

Toxicology and Epidemiology Branch 

Health Effects Division (7509P) 

TO: Jessica Kidwell, Risk Assessor 

Risk Assessment Branch IV 

Health Effects Division (7509P) 

and 

Susan Bartow, Chemical Review Manager 

Risk Management & Implementation Branch 4 

Pesticide Re-evaluation Division (7508P) 

Summary and Conclusions 

Based on the low frequency and severity of incident cases reported for ethylene oxide 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. Ethylene oxide 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 

In the U.S., ETO is primarily used to sterilize medical equipment, phannaceuticals, and aseptic 

packaging. However, ETO is also used to reduce microbial populations on whole and ground 

spices and dried vegetables. Fumigation with ETO must be performed in vacuum chambers with 

outside venting designed for use with ETO. It is applied by commercial applicators only; there 

are no residential uses ofETO. ETO has three reaction products- ethylene bromohydrin (EBH), 

ethylene chlorohydrin (ECH), and ethylene glycol (EG). 

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 ethylene oxide (PC Code: 042301). 

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

of the health effects attributed to ethylene oxide 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. Ethylene oxide is not included in the AHS, and 

therefore this study does not provide information for this report. 

III. RESULTS/DISCUSSION 

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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 

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 1 incident reported in 

the database. This incident was classified as major severity. This incident is described further in 

Table 1. Overall, there are few incidents involving ethylene oxide reported to IDS. 

In Aggregate IDS, from January 1, 2008 to February 19, 2013, there were 3 reported incidents 

involving ethylene oxide. These incidents were classified as minor severity. 

T bl 1 M . IDS M . .d a e am a] or nc1 ents £ or t h e smgl e c h . 1 emtca E t h 1y1en 1 e 0 x1 .d e 

Human Incident Chemical: Ethylene Oxide I PC Code: 04230 I 

Incident 

Package Incident Reg Exposure 

Report Date Location Number Product Name Severity* Incident DescriJ>tion 

An employee attributes 

Acute Promyleocytic 

Leukemia to his exposure to 

ethylene oxide gas (SterGas Cartridge) in his 6 yrs of 

employment as sterilization 

personnel. His workers 

compensation claim was 

denied. He was able to 

show that he was exposed 

to ETO but not a connection 

023423 SPOKANE, 007182- STERI-GAS between his exposure and 

- 00001 9/1/2011 WA 00001 CARTRIDGE HB his diagnosis. 

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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. 

A query of SENSOR-Pesticides 1998-2009 identifies 9 cases, stemming from 5 events, involving 

ethylene oxide. All cases/events involved a single ai. One case was classified as moderate 

severity and eight cases were classified as low in severity. Eight of nine cases were workrelated; seven of nine cases were exposed in a hospital. The moderate severity case narrative 

states "case was exposed to ethylene oxide at hospital where she works while she and another 

coworker were doing routine work". 

One event that occurred in Michigan in 2006 (Event ID # MI00693) resulted in 4 SENSOR case 

reports. Event information states "A partially used ethylene oxide (ETO) canister, which had 

been improperly placed on the ETO machine, fell to the floor of the surgical processing room. It 

cracked & released ETO. 15 people were evacuated from the area & decontaminated. Six 

individuals with symptoms were sent to occupational health.'' The reported health effects for 

these cases are summarized in Table 2. 

Table 2. SENSOR-Pesticides 1998-2009: 

Reported Health Effects for Ethylene 

Oxide Cases (N=9) 

Health Effect 

#of Times 

Reported 

Dermal I 

Ocular 2 

Respiratory 6 

Gastrointestinal 5 

Renal 0 

Nervous System 7 

Cardiovascular 0 

Misc. 1 

* Cases may report multiple health effects 

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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. 

Ethylene oxide 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 ethylene oxide 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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