Document ID: EPA-HQ-OPP-2005-0128-0062
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-05-02T04:00Z

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

		  		WASHINGTON, D.C. 20460

							                                      		   OFFICE OF

				PREVENTION, PESTICIDES

	AND TOXIC SUBSTANCES

MEMORANDUM

SUBJECT:	Special Review and Reregistration Division (SRRD) Response to
Public Comments

TO:		Dazomet Public Docket

		EPA-HQ-OPP-2005-0128

FROM:	Cathryn O’Connell, Chemical Review Manager

		Special Review and Reregistration Division (7508C)

DATE:	April 25, 2007

THRU:	Margaret Rice, Branch Chief

		Special Review and Reregistration Division (7508C) 

This memo is a response from SRRD to the comments related to
registration and policy issues that the Agency received during the Phase
3 public comment period for dazomet, which opened July 13, 2005.  The
Agency received dazomet specific comments from the dazomet technical
registrant, Certis USA, and one MITC comment from the Pesticide Action
Network North America (PANNA).  In addition, the Agency received
comments that addressed the entire soil fumigant group (methyl bromide,
metam sodium/potassium, dazomet, chloropicrin, and 1,3-D) from private
citizens, the California Minor Crops Council, and the PANNA.  

Dazomet-specific comments pertaining to toxicology and occupational and
residential risk are addressed in separate documents from the Health
Effects Division (document number OPP-2005-0128-0033, April 12, 2007, DP
barcode D339247).  This response to comment document is available in the
dazomet docket.

MITC Comment

1.  Comment from Pesticide Action Network North America
(OPP-2005-0128-0026) 

“We are extremely concerned about the numerous MITC toxicology data
gaps and conclude that use of metam sodium and dazomet should not be
allowed to continue with the many gaps in our knowledge of potential
short and long-term effects of MITC exposure. The industry has already
had many years to fill these data gaps. We concur with the conclusions
expressed by the Agency that inhalation carcinogenicity studies in rats
and mice and an acute inhalation neurotoxicity study in rats including
pathological evaluation of the upper and lower respiratory tract are
needed for MITC. The Agency should request initiation of these studies
without further delay and prohibit all uses of MITC-generating chemicals
until the data are received.”

Response

The Agency agrees that these toxicity studies are necessary, and will be
requiring them in the Data Call-In after the RED is completed.  The
Agency is encouraging registrants to initiate these studies as soon as
possible. In addition, mitigation to reduce acute exposures will also
reduce the likelihood of chronic exposures.

General Fumigant Comments

2.  Comment from Private Citizens—Campaign Letters
(OPP-2005-0128-0018)

These letters (853 total letters) urge the EPA to phase out fumigants
due to adverse health effects on workers, and community members.  The
letters suggest that EPA work with USDA to 1) Support research into
modern pest control methods that utilize our knowledge of soil pest
biology and pest-resistant varieties, and 2) Provide outreach to farmers
to assist them in the transition to farming practices that do not harm
people and the environment.  

Response

The Agency appreciates the input from these commenters.  The revised
human health risk assessments for the soil fumigants include a section
on worker and community incidents.  Acute symptoms in documented
incidents for certain fumigants (such as metam sodium and chloropicrin)
include those mentioned in the comment letters; unfortunately, it is not
usually possible to conclusively identify the cause (or multiple causes)
of chronic illnesses.

EPA is working with USDA and other stakeholders to reduce the amount of
fumigants necessary for pest control.  Part of the effort includes
research on “sealing” methods to determine if the seals allow lower
fumigant applications while still remaining efficacious.  Regarding
outreach to farmers, sections of the Agency’s Risk Mitigation Options
Paper (document number OPP-2005-0128-0030, dated 4/18/2007) discuss
stewardship programs and good agricultural practices.  These mitigation
measures will assist farmers with fumigant usage that does not harm
people or the environment.  

3.  Comment from California Minor Crops Council (OPP-2005-0128-0024)

“We would like to share our concern for the importance of the use of
correct assumptions regarding use rates and application methodologies
for each of the soil fumigants under reviews as part of the cluster
analysis.  It is imperative that the assumptions used in the risk
assessments for the soil fumigants are based on actual use practices. 
Given the importance of all of the soil fumigants as crop protection
tools, the accurate determination and portrayal of risk is critical to
the user community and the public in the perception about the safety of
their use.”  

Response

The Agency agrees that correct assumptions should be used and has sought
public input on application rates and application methods for use in the
risk assessments.  The Agency welcomes any additional specific use
information (e.g., regionally-specific information, or information
highlighting unique use circumstances) during the Phase 5 public comment
period.

4.  Comment from Pesticide Action Network North America
(OPP-2005-0128-0025) 

“Safe use of these fumigants cannot be ensured, as indicated by the
number and severity of poisoning incidents for different fumigants.  We
highlight a number of these poisonings and their effects on the lives of
individuals and strongly urge EPA to phase out the use of these
chemicals.”

Response

The Agency appreciates the incident information and has incorporated
this information into our fumigant incident reports.  We will consider
this information in developing our risk management decisions.

5.  Comment from Pesticide Action Network North America
(OPP-2005-0128-0025)

“The FQPA’s “reasonable certainty of no harm” standard is not
consistently employed in risk assessment, nor is a consideration of all
routes of exposure to ensure adults and children are protected.” 

Response

EPA regulates pesticides under the Federal Insecticide, Fungicide, and
Rodenticide Act (FIFRA) and the Federal Food, Drug, & Cosmetic Act
(FFDCA).  Both of these laws were amended in 1996 by the Food Quality
Protection Act (FQPA).  A pesticide is subject to FQPA’s “reasonable
certainty of no harm” standard if the pesticide has tolerances. 
Dazomet was reassessed according to the FIFRA standard that there is no
“unreasonable adverse effect” from the pesticide to the environment.
 Under FIFRA, the Agency considers and assesses all routes of exposure
to adults and children in order to ensure that they are protected. 

6.  Comment from Pesticide Action Network North America
(OPP-2005-0128-0025)

“Real world conditions warrant assessment of cumulative risks of
exposure to multiple fumigants to ensure protection of the most
fumigant-affected populations, i.e. farm workers and nearby residents. 

Non-chemical alternatives to fumigants exist, are documented, and
warrant greater emphasis and evaluation. EPA plays a key role in calling
out these alternatives to USDA to develop methods of support for farmers
to ensure a just transition to alternatives.

Affected communities must be consulted at all stages of the fumigant
cluster assessment process.”

Response

The Agency is considering limiting the number of fumigations within the
same general area within a 24-hour period, as an option to decrease
bystander and occupational exposure to multiple fumigants.  This option
along with others can be found in the Agency’s paper, “Risk
Mitigation Options to Address Bystander and Occupational Exposures from
Soil Fumigant Applications.”  This paper can be found on   HYPERLINK
"http://www.regulations.gov_"  http://www.regulations.gov  in the
Dazomet Docket, EPA-HQ-OPP-2005-0128-0030.   The EPA is soliciting
public comments on this paper.  

The Agency is aware of the use of non-chemical alternatives and has
considered these in its benefits assessments.  The Agency will also
consider non-chemical alternatives, along with other risk mitigation
options, in making its regulatory decisions.  EPA is working closely
with USDA on the reregistration of the soil fumigants.

In addition to providing the opportunity for stakeholders to submit
written comments to the docket during the Phase 5 comment period, EPA is
holding stakeholder meetings in Washington State and Florida.  The
purpose of the meetings is to allow for input by stakeholders who might
not otherwise participate in the formal comment submission process.  In
addition, EPA will attend CDPR’s  public stakeholder meeting on their
MITC mitigation proposal, to hear stakeholder comments.

7.  Comment from Pesticide Action Network North America
(OPP-2005-0128-0025)

“EPA must seriously consider existing viable alternatives.  The
substantial evidence of the hazards fumigants pose to workers and
bystanders indicates that EPA cannot be assured that there is a
reasonable certainty of no harm from registration and use of these
chemicals. For workers especially, it is clear that the extreme risks
outweigh the limited benefits.

The fumigants considered in this cluster assessment have viable
non-toxic alternatives that are being used successfully for
fumigant-intensive crops in many climatic and ecological zones. These
fumigants continue to be responsible for mass poisonings as well as
chronic adverse health effects. We urge EPA to invest more resources in
alternatives assessment work with USDA to help farmers transition away
from fumigants as a soil pest control strategy.”

Response

EPA is considering non-chemical alternatives as part of its benefits
assessments and in its development of regulatory decisions for the soil
fumigants.  The Agency is also considering the risks to workers and
bystanders, as demonstrated through three lines of evidence: documented
incidents, air monitoring data, and modeling estimates. 

The Agency is aware of the use of non-chemical alternatives and has
considered these in its benefits assessments.  The Agency will also
consider non-chemical alternatives, along with other risk mitigation
options, in making its regulatory decisions.  EPA is working closely
with USDA on the reregistration of the soil fumigants.

8.  Comment from Pesticide Action Network North America
(OPP-2005-0128-0026)

“Both maximum and whole field methods are discussed in EPA’s
preliminary risk assessment.

Since populations may live downwind of a field in the prevailing wind
direction, it is important to use the maximum method for exposure
assessment. The whole field method would average the concentrations
rather than protecting the most exposed population. This would not be
adequately protective.”

Response 

As in EPA’s preliminary human health risk assessments, the revised
risk assessments for the soil fumigants present PERFUM modeling results
using both maximum and whole field distributions to allow side-by-side
comparisons.  The assessments also include updated descriptions of each
type of distribution.  At this time, the Agency has not yet made any
decision regarding buffer zone distances for the soil fumigants.  Buffer
zones and other risk mitigation measures under consideration are
presented in the risk mitigation options paper (document number
OPP-2005-0128-0030, dated 4/18/07).  The Agency is currently soliciting
comments on these proposed risk mitigation options.

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