Office of Inspector General

U.S. Environmental Protection Agency

At a Glance

22-E-0053
July 20, 2022

Why We Did This Evaluation

We performed this evaluation to
examine the extent to which the
U.S. Environmental Protection
Agency followed policies and
procedures in developing the
cancer assessment for the
1,3-Dichloropropene pesticide-
registration-review decision to
prevent unreasonable adverse
effects on human health. We
initiated this evaluation based on
multiple complaints submitted to
the Office of Inspector General
Hotline.

The Federal Insecticide, Fungicide,
and Rodenticide Act requires the
EPA to review every pesticide
registration no later than 15 years
after the active ingredient's initial
registration to determine whether
the pesticide continues to meet the
statutory standard—that is,
whether the pesticide performs its
intended function without
unreasonable adverse effects on
human health and the environment.
When registered pesticides are
reviewed as part of the 15-year
registration review process, the
EPA does not typically initiate a
new cancer assessment unless
requested by the registrant through
the Pesticide Registration
Improvement Act.

This evaluation supports an EPA
mission-related effort:

•	Ensuring the safety of chemicals.

This evaluation addresses these top
EPA management challenges:

•	Ensuring the safe use of
chemicals.

•	Safeguarding scientific integrity.

Address inquiries to our public
affairs office at (202) 566-2391 or
OIG WEBCOMMENTS@epa.gov.

List of OIG reports.

The EPA Needs to Improve the Transparency of
Its Cancer-Assessment Process for Pesticides

Deficiencies and a lack of
transparency in the
1,3-D pesticide
cancer-assessment
process has undermined
scientific credibility and
public confidence.

What We Found

The EPA did not adhere to standard operating
procedures and requirements for the
1,3-Dichloropropene, or 1,3-D, pesticide
cancer-assessment process, which undermines
public confidence in and the transparency of
the Agency's scientific approaches to prevent
unreasonable impacts on human health.

Specifically, the EPA used two scientific

approaches, kinetically derived maximum dose and weight-of-evidence, in its
cancer-assessment process for 1,3-D, even though it did not have guidance
outlining how to use those approaches. The EPA also did not adhere to
docketing and transparency requirements to provide the public and
stakeholders with information that may have influenced the EPA's
cancer-assessment decision. Further, the EPA did not follow its
literature-search procedures and neglected to document its review of all
health effects data that may have impacted the results of the 1,3-D draft
human health risk assessment, which is informed by the cancer assessment.
The EPA's Cancer Risk Assessment Committee did not adhere to the EPA's
Peer Review Handbook and the Office of Management and Budget's
guidance on peer review in the areas of composition, independence, and
expertise. These deficiencies undermined the scientific credibility of the
1,3-D cancer assessment, which led to questioning by multiple stakeholders.
An external peer review would have improved the credibility of the
1,3-D cancer assessment.

Recommendations and Planned Agency Corrective Actions

We make nine recommendations to improve the transparency of the
1,3-D cancer-assessment process and restore the scientific credibility of the
Agency's 1,3-D cancer classification. These recommendations address the
lack of guidance for the EPA's use of the kinetically derived maximum dose
and weight-of-evidence approaches, an incomplete public docket, an
incomplete literature search, noncompliance with internal peer review
standards, and the need for an external peer review. These
recommendations will also improve the EPA's cancer-assessment process for
pesticides more broadly.

The EPA was not in full agreement with Recommendations 1, 2, and 8, which
remain unresolved. We are in discussions with the EPA on the unresolved
recommendations. The EPA generally agreed with Recommendations 3-7
and 9, which are resolved with corrective actions pending.

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