UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

		  WASHINGTON, D.C. 20460

							                                         OFFICE OF

				PREVENTION, PESTICIDES

	AND TOXIC SUBSTANCES

MEMORANDUM

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

TO:		Chloropicrin Public Docket

		EPA-HQ-OPP-2007-0350

FROM:	Nathan Mottl

		Kelly Sherman

		Susan Lewis, Branch Chief

		Special Review Branch

		Special Review and Reregistration Division (7508P)

THRU:	Peter Caulkins, Acting Director

		Special Review and Reregistration Division (7508C) 

1. CRLA comments

Buffer zones should be protective during worst case weather conditions.
This risk assessment presents buffer zone estimates using both “whole
field” and “maximum direction” modeling methods. In our opinion,
the “maximum direction” computer modeling method which puts only the
maximum air concentration at a given buffer predicted on each day into
the computer model should be used instead of the whole field method.

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.  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 in the fumigant dockets (see “Risk Mitigation
Options to Address Bystander and Occupational Exposures from Soil
Fumigant Applications”).  The Agency is currently soliciting comments
on these proposed risk mitigation options.

2. CRLA comments

The Agency has no data on handler exposures to chloropicrin during
greenhouse, grain bin, and potato cellar use. These uses of products as
an active ingredient (rather than just a warning agent at 2%
concentration) should be suspended until exposure data is submitted and
accepted by the Agency.

Response

The exposure data issue will be addressed later when the EPA develops
the Reregistration Eligibility Decision (RED) document in Phase 6.

3. Multiple Commentors

Buffer zones should not be the preliminary focus of the risk assessment
as agricultural practice dramatically impact emissions.  Application
practices such as establishing proper soil moisture, soil sealing using
cultipackers or tarping, and depth of injection significantly impact
chloropicrin emissions are more effective tools than buffer zones for
preventing worker and bystander exposure.  The good agricultural
practice should be considered rather than buffer zones to address
concerns.

Response

No decisions on buffer zones or other risk mitigation measures have been
made by the EPA yet.  This comment will be considered by the Agency. 
Furthermore, EPA is soliciting comments on risk mitigation options for
all of the fumigants (see “Risk Mitigation Options to Address
Bystander and Occupational Exposures from Soil Fumigant
Applications”).  The Risk Options Paper discusses the good
agricultural practices and EPA encourages stakeholders to submit
writtern responses to the docket during the Phase 5 comment period.

4. Multiple Commentors

Moderate buffer zones, much less 1400 meter for chloropicrin would be
devastating to grower.

Response

No decisions on buffer zones or other risk mitigation measures have been
made by the EPA yet (see response 3). 

The revised risk assessment raises some concern for growers. Current
models addressing issues of off-gassing to bystander, drift, restrictive
buffers and the proposed handler/applicator requirements need to be
evaluated as to appropriateness and practicality for implementation.  We
look forward to continued discussions as the decision making process on
Chloropicrin and other soil fumigants move forward.

Response

No decisions on buffer zones or other risk mitigation measures (e.g.
handler applicator requirements) have been made by the EPA yet.
Furthermore, EPA is soliciting comments on risk mitigation options for
all of the fumigants (see “Risk Mitigation Options to Address
Bystander and Occupational Exposures from Soil Fumigant
Applications”). EPA appreciates the need for public comment on risk
mitigation options and to meet this need is scheduling public meetings
to discuss the risk mitigation options (Reference the FR Notice for
Stakeholder Meetings??). The purpose of the meetings are for the Agency
to obtain first-hand comments on possible human health risk mitigation
options from stakeholders who are most affected by soil fumigant use,
including growers, professional fumigant applicators, farm workers,
neighbors and community members, local officials, and others.   EPA
appreciates the comments that stakeholders have on chloropicrin and also
encourages stakeholders to provide specific comments in the public
docket on EPA’s risk mitigation options paper.

5. Multiple Commentors

With the phase out of methyl bromide, chloropicrin has become
increasingly important. Using methyl bromide formulations with a higher
proportion of chloropicrin is a strategic part of our methyl bromide
alternative strategy??

Should I address this one??

