Document ID: EPA-HQ-OPP-2007-0350-0175
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-07-16T04:00Z

Revised Screening Ecological Risk Assessment for the Reregistration of
Chloropicrin

Prepared by:

Faruque Khan, Senior Scientist 

James Felkel, Wildlife Biologist

	U. S. Environmental Protection Agency

Office of Pesticide Programs

Environmental Fate and Effects Division

Environmental Risk Branch IV

Ariel Rios Building (Mail Code 7507C) 

1200 Pennsylvania Ave., NW

Washington, DC 20460

Reviewed by:

Ron Parker, Environmental Engineer (original version)

Nick Federoff, Wildlife Biologist (original version)

Jean Holmes, RAPL (original version)

Mah Shamim, Branch Chief

	

TABLE OF CONTENTS

  TOC \f \h \z    HYPERLINK \l "_Toc163287269"  I.  Executive Summary	 
PAGEREF _Toc163287269 \h  4  

  HYPERLINK \l "_Toc163287270"  A.  Nature of Chemical Stressor	 
PAGEREF _Toc163287270 \h  4  

  HYPERLINK \l "_Toc163287271"  B.  Conclusions - Exposure
Characterization	  PAGEREF _Toc163287271 \h  4  

  HYPERLINK \l "_Toc163287272"  C.  Potential Risks to Non-target
Organisms	  PAGEREF _Toc163287272 \h  5  

  HYPERLINK \l "_Toc163287273"  Risks to Aquatic Animals	  PAGEREF
_Toc163287273 \h  5  

  HYPERLINK \l "_Toc163287274"  Risks to Terrestrial Animals	  PAGEREF
_Toc163287274 \h  5  

  HYPERLINK \l "_Toc163287275"  Risks to Aquatic and Terrestrial Plants	
 PAGEREF _Toc163287275 \h  6  

  HYPERLINK \l "_Toc163287276"  D.  Conclusions - Effects
Characterization	  PAGEREF _Toc163287276 \h  6  

  HYPERLINK \l "_Toc163287277"  E.  Data Gaps and Uncertainties	 
PAGEREF _Toc163287277 \h  6  

  HYPERLINK \l "_Toc163287278"  1. Environmental Fate and Exposure	 
PAGEREF _Toc163287278 \h  6  

  HYPERLINK \l "_Toc163287279"  2. Ecological Effects	  PAGEREF
_Toc163287279 \h  7  

  HYPERLINK \l "_Toc163287280"  II.  Problem Formulation	  PAGEREF
_Toc163287280 \h  10  

  HYPERLINK \l "_Toc163287281"  A.  Stressor Source and Distribution	 
PAGEREF _Toc163287281 \h  10  

  HYPERLINK \l "_Toc163287282"  1.  Source and Intensity	  PAGEREF
_Toc163287282 \h  10  

  HYPERLINK \l "_Toc163287283"  2.  Physical/Chemical/Fate and Transport
Properties	  PAGEREF _Toc163287283 \h  10  

  HYPERLINK \l "_Toc163287284"  3.  Pesticide Type, Class, and Mode of
Action	  PAGEREF _Toc163287284 \h  10  

  HYPERLINK \l "_Toc163287285"  4.  Overview of Pesticide Usage	 
PAGEREF _Toc163287285 \h  10  

  HYPERLINK \l "_Toc163287286"  B.  Receptors	  PAGEREF _Toc163287286 \h
 11  

  HYPERLINK \l "_Toc163287287"  1.  Ecological Effects	  PAGEREF
_Toc163287287 \h  11  

  HYPERLINK \l "_Toc163287288"  2.  Ecosystems Potentially At Risk	 
PAGEREF _Toc163287288 \h  13  

  HYPERLINK \l "_Toc163287289"  C.  Assessment Endpoints	  PAGEREF
_Toc163287289 \h  14  

  HYPERLINK \l "_Toc163287290"  D.  Conceptual Model	  PAGEREF
_Toc163287290 \h  14  

  HYPERLINK \l "_Toc163287291"  1.  Risk Hypotheses	  PAGEREF
_Toc163287291 \h  14  

  HYPERLINK \l "_Toc163287292"  2.  Diagram	  PAGEREF _Toc163287292 \h 
15  

  HYPERLINK \l "_Toc163287293"  E.  Analysis Plan	  PAGEREF
_Toc163287293 \h  17  

  HYPERLINK \l "_Toc163287294"  1. Preliminary Identification of Data
Gaps and Methods	  PAGEREF _Toc163287294 \h  17  

  HYPERLINK \l "_Toc163287295"  2.  Measures to Evaluate Risk Hypotheses
and Conceptual Model	  PAGEREF _Toc163287295 \h  19  

  HYPERLINK \l "_Toc163287296"  a.  Measures of Exposure	  PAGEREF
_Toc163287296 \h  19  

  HYPERLINK \l "_Toc163287297"  b.  Measures of Effect	  PAGEREF
_Toc163287297 \h  19  

  HYPERLINK \l "_Toc163287298"  c.  Measures of Ecosystem and Receptor
Characteristics	  PAGEREF _Toc163287298 \h  20  

  HYPERLINK \l "_Toc163287299"  III.  Analysis	  PAGEREF _Toc163287299
\h  21  

  HYPERLINK \l "_Toc163287300"  A.  Use Characterization	  PAGEREF
_Toc163287300 \h  21  

  HYPERLINK \l "_Toc163287301"  B.  Exposure Characterization	  PAGEREF
_Toc163287301 \h  23  

  HYPERLINK \l "_Toc163287302"  1.  Environmental Fate and Transport
Characterization	  PAGEREF _Toc163287302 \h  23  

  HYPERLINK \l "_Toc163287303"  1.  Environmental Fate and Transport
Characterization	  PAGEREF _Toc163287303 \h  23  

  HYPERLINK \l "_Toc163287304"  (a) Fate and Transport in soil and water
  PAGEREF _Toc163287304 \h  25  

  HYPERLINK \l "_Toc163287305"  (b) Fate and Transport in atmosphere	 
PAGEREF _Toc163287305 \h  26  

  HYPERLINK \l "_Toc163287306"  (c) Ozone Depletion Potential	  PAGEREF
_Toc163287306 \h  28  

  HYPERLINK \l "_Toc163287307"  2.  Measures of Terrestrial Exposure	 
PAGEREF _Toc163287307 \h  28  

  HYPERLINK \l "_Toc163287308"  (a)Terrestrial Exposure Modeling	 
PAGEREF _Toc163287308 \h  28  

  HYPERLINK \l "_Toc163287309"  (b) Terrestrial Exposure Monitoring Data
  PAGEREF _Toc163287309 \h  30  

  HYPERLINK \l "_Toc163287310"  3.  Measures of Aquatic Exposure	 
PAGEREF _Toc163287310 \h  32  

  HYPERLINK \l "_Toc163287311"  a.  Aquatic Exposure Modeling	  PAGEREF
_Toc163287311 \h  32  

  HYPERLINK \l "_Toc163287312"  b.  Aquatic Exposure Monitoring and
Field Data	  PAGEREF _Toc163287312 \h  35  

  HYPERLINK \l "_Toc163287313"  C.  Ecological Effects Characterization	
 PAGEREF _Toc163287313 \h  35  

  HYPERLINK \l "_Toc163287314"  1.  Aquatic Effects Characterization	 
PAGEREF _Toc163287314 \h  36  

  HYPERLINK \l "_Toc163287315"  2.  Terrestrial Effects Characterization
  PAGEREF _Toc163287315 \h  37  

  HYPERLINK \l "_Toc163287316"  IV.  Risk Characterization	  PAGEREF
_Toc163287316 \h  39  

  HYPERLINK \l "_Toc163287317"  A.  Risk Estimation - Integration of
Exposure and Effects Data	  PAGEREF _Toc163287317 \h  39  

  HYPERLINK \l "_Toc163287318"  1.  Non-target Aquatic Animals and
Plants	  PAGEREF _Toc163287318 \h  39  

  HYPERLINK \l "_Toc163287319"  2.  Non-target Terrestrial Animals	 
PAGEREF _Toc163287319 \h  41  

  HYPERLINK \l "_Toc163287320"  3.  Non-target Terrestrial and
Semi-aquatic Plants	  PAGEREF _Toc163287320 \h  42  

  HYPERLINK \l "_Toc163287321"  B.  Risk Description	  PAGEREF
_Toc163287321 \h  43  

  HYPERLINK \l "_Toc163287322"  1.  Risk to Aquatic Organisms	  PAGEREF
_Toc163287322 \h  43  

  HYPERLINK \l "_Toc163287323"  2.  Risk to Terrestrial Organisms	 
PAGEREF _Toc163287323 \h  43  

  HYPERLINK \l "_Toc163287324"  3.  Review of Incident Data	  PAGEREF
_Toc163287324 \h  46  

  HYPERLINK \l "_Toc163287325"  4.  Endocrine Disruption	  PAGEREF
_Toc163287325 \h  47  

  HYPERLINK \l "_Toc163287326"  5.  Federally Threatened and Endangered
(Listed) Species Concerns	  PAGEREF _Toc163287326 \h  48  

  HYPERLINK \l "_Toc163287327"  A.  Action Area	  PAGEREF _Toc163287327
\h  48  

  HYPERLINK \l "_Toc163287328"  B. Taxonomic Groups Potentially at Risk	
 PAGEREF _Toc163287328 \h  49  

  HYPERLINK \l "_Toc163287329"  1.  Discussion of Risk Quotients	 
PAGEREF _Toc163287329 \h  49  

  HYPERLINK \l "_Toc163287330"  2.  Probit Dose Response Relationship	 
PAGEREF _Toc163287330 \h  50  

  HYPERLINK \l "_Toc163287331"  C.  Data Related to Under-represented
Taxa	  PAGEREF _Toc163287331 \h  51  

  HYPERLINK \l "_Toc163287332"  D.  Implications of Sublethal Effects	 
PAGEREF _Toc163287332 \h  51  

  HYPERLINK \l "_Toc163287333"  E.  Indirect Effects Analysis	  PAGEREF
_Toc163287333 \h  51  

  HYPERLINK \l "_Toc163287334"  F.  Critical Habitat	  PAGEREF
_Toc163287334 \h  52  

  HYPERLINK \l "_Toc163287335"  G.  Co-occurrence Analysis	  PAGEREF
_Toc163287335 \h  52  

  HYPERLINK \l "_Toc163287336"  V. Literature Cited	  PAGEREF
_Toc163287336 \h  54  

  HYPERLINK \l "_Toc163287337"  VI. Appendices	  PAGEREF _Toc163287337
\h  58  

  HYPERLINK \l "_Toc163287338"  Appendix A.  Environmental Fate and
Transport Data	  PAGEREF _Toc163287338 \h  59  

  HYPERLINK \l "_Toc163287339"  Appendix B. Aquatic Exposure PRZM/EXAMS
Modeling	  PAGEREF _Toc163287339 \h  68  

  HYPERLINK \l "_Toc163287340"  Appendix C:  Ecological Effects Data	 
PAGEREF _Toc163287340 \h  92  

  HYPERLINK \l "_Toc163287341"  Appendix D.  The  Risk Quotient Method
and Levels of Concern	  PAGEREF _Toc163287341 \h  104  

  HYPERLINK \l "_Toc163287342"  Appendix E.    Data Requirement Tables	 
PAGEREF _Toc163287342 \h  106  

 Appendix F  HYPERLINK \l "_Toc163287342"  .    Terrestrial Exposure
Modeling-PERFUM	  PAGEREF _Toc163287342 \h  106  

CONVERSION FACTORS

To convert concentrations in air (at 25 °C) from ppm to mg/m3: mg/m3 =
(ppm) ×(molecular weight of the compound)/(24.45).I.  Executive
Summary  TC "I.  Executive Summary" \f C \l "1"  

	A.  Nature of Chemical Stressor  TC "A.  Nature of Chemical Stressor"
\f C \l "2"   

	Chloropicrin, a pre-plant soil fumigant is used in controlling a broad
range of soil pathogens. It is a clear, colorless, nonflammable oily
liquid with strong, sharp, highly irritating odor and is a strong
lacrimator (tear-producer). Chloropicrin’s specific mode of action is
not understood, but it is a strong irritant that is very toxic to all
biological systems; affecting body surfaces and interfering with the
respiratory system and the cellular transport of oxygen (U.S. Forest
Service, 1995). Chloropicrin is typically applied once per growing
season through soil injection or drip irrigation to fumigate the upper
six to twelve inches of soil as a liquid 14 days or more before
planting. The maximum application rate being supported for
reregistration is 350 lbs ai/A, with 300 lbs ai/A the maximum for drip
irrigation. 

	B.  Conclusions - Exposure Characterization  TC "B.  Conclusions -
Exposure Characterization" \f C \l "2"  

	The high vapor pressure (23.8 mm @ 25○C), high Henry’s Law Constant
(2.05 X 10-3 atm M3/mole), and low affinity for sorption (Koc 36.05 L
kg-1) on soil of chloropicrin suggest that volatilization is the most
important environmental route of dissipation.  The importance of other
competing environmental processes such as leaching, biotic and abiotic
degradation, and adsorption to the soil particles will certainly depend
on the chloropicrin emission rate, weather conditions, and soil
characteristics of the fumigated fields. Fumigant post-application field
management practices like splitting, retaining or removing tarp from the
fumigated field also determine the amount of chloropicrin that will be
available for other competing environmental processes and its residence
time in soil. The estimated biodegradation half-lives of chloropicrin in
soil range from 3.7 to 4.5 days, with carbon dioxide being the terminal
breakdown product.

	Once it volatilized, chloropicrin photolyzes rapidly with an estimated
atmospheric half-life of 3.4 to 8 hours in direct sunlight, leading to
an estimate of 1 day for its atmospheric lifetime. With an ozone
depletion potential more than four orders of magnitude (5.6x10-5  versus
0.38) less than the ozone depleting substances such as methyl bromide,
chloropicrin is not a threat to stratospheric ozone. The major
degradation products were phosgene (carbonyl chloride) and nitrosyl
chloride, which rapidly photolyzes to reactive products NO and Cl•.
Continued oxidation of the chloropicrin photolysis products would
eventually produce CO2, NO2, N2O4, and Cl2. The reactive byproducts of
chloropicrin photolysis, in particular chlorine free radicals and NOx,
could lead to the generation of tropospheric ozone. Since the
metabolites of chloropinrin are very reactive and unstable in the
atmosphere, they were not considered in the risk assessment.

	

	Since chloropicrin is highly soluble in water and has low adsorption in
soil, residual chloropicrin in soil can potentially leach into
groundwater under continuos irrigation and high rainfall events and to
surface water through runoff under a flooded condition. The calculated
half-life of 31.1 hours is for chloropicrin in aqueous solution (pH 7)
when irradiated with a 

xenon light source, forming carbon dioxide, chloride, nitrate and
nitrite. The high Henry’s Law Constant (2.05 X 10-3 atm M3/mole) and
rapid photohydrolysis of chloropicrin suggest that volatilization and
rapid abiotic degradation are the most important routes of dissipation
from surface water. Also, the low octanol/water partition coefficient of
chloropicrin indicates that it is not likely to be bioconcentrated in
tissues of aquatic organisms. Chloropicrin was found at less than 1.00
μg/L in three wells from 15,175 wells in Florida.  However, no
monitoring data of chloropicrin in surface water are available at the
present time.

	C.  Potential Risks to Non-target Organisms

  TC "C.  Potential Risks to Non-target Organisms" \f C \l "2"  

	This is a Level I screening assessment.  EFED has a strong presumption
of acute risk to all exposed plants and animals, since chloropicrin is a
broad-spectrum fumigant.  It is assumed that all living organisms in the
treated soil (including beneficial insects and burrowing mammals, for
example) are at high risk of mortality.  In addition, a wide range of
terrestrial and aquatic non-target organisms off-site may also be at
risk.   Chloropicrin appears to pose risks to mammals and birds based on
ISCT3 modeled air residues, exceeding an equivalent acute Level of
Concern (LOC) for endangered species.  It also exceeds LOCs (including
acute endangered species) for fish with five of six modeled scenarios
and for aquatic invertebrates for at least two of six scenarios. 
However, there are substantial uncertainties in estimating ecological
effects of chloropicrin due to limited toxicity data and the limitations
of current exposure models and crop scenarios.  The PRZM model also has
limited capabilities in capturing the partitions of volatile chemical in
air, water and sediment.  No fully acceptable toxicity data are
available, except for the mammal acute oral and chronic inhalation data
used, and thus uncertainty levels are high.

		Risks to Aquatic Animals  TC "Risks to Aquatic Animals" \f C \l "3"  	

Of the six modeled scenarios, chloropicrin exceeds Levels-of-Concern
(acute endangered species, acute restricted use, and/or acute risk) 1)
for fish, with five of six scenarios (California onions, Florida
tomatoes, Florida strawberries, North Carolina sweet potatoes, and North
Carolina tobacco; maximum risk quotients for the five scenarios range
from 0.15 to 15.32, and 2) for aquatic invertebrates, with at least
Florida tomatoes and strawberries (maximum risk quotients range from
>0.01 to >1.11 for the five scenarios; because of indeterminate risk
quotients, other modeled sites could potentially exceed LOCs as well). 
Other use sites not modeled may be in the same range as modeled sites. 
These risks would also apply to other aquatic animals such as aquatic
phase amphibians. However, there are also substantial uncertainties
concerning exposure modeling values, as described below (in Data Gaps
and Uncertainties).

		Risks to Terrestrial Animals  TC "Risks to Terrestrial Animals" \f C
\l "3"  

	The risk to non-target terrestrial animals off-site is primarily from
inhalation of chloropicrin off-gassed from treated fields.  EFED does
not have LOCs specifically for inhalation exposure.  However, based on
modeled air residues and acute toxicity data available from Health
Effects Division, chloropicrin would exceed the existing LOC for acute
risk to endangered species for mammals (using ISCT3 modeling, but not
PERFUM modeling).  Based on the mammal analysis, it is assumed that
birds could be at a similar risk.  Other terrestrial wildlife (e.g.,
reptiles and terrestrial phase amphibians) may also be at risk.  There
is also a concern for sublethal effects from chloropicrin.  For example,
if chloropicrin caused terrestrial wildlife to flee a nesting area,
reproduction could be adversely affected. 

		Risks to Aquatic and Terrestrial Plants  TC "Risks to Aquatic and
Terrestrial Plants" \f C \l "3"  

	Although no guideline plant data are available for chloropicrin, label
and other information citing phytotoxicity potential on treated sites
implies that off-gassed chloropicrin might also pose a risk to
terrestrial plants and that modeled aquatic residues might pose a risk
to aquatic plants.

	D.  Conclusions - Effects Characterization  TC "D.  Conclusions -
Effects Characterization" \f C \l "2"  

	Based on very limited data, chloropicrin is considered very highly
toxic to both fish (lowest LC50 = 5.14 ppb) and aquatic invertebrates
(lowest LC50 < 71 ppb).  The acute mammal inhalation LD50 is 0.114 mg/L
(male rats) and the developmental NOAEL in rabbits is 0.003 mg/L (LOAEL
0.008 mg/L, based on abortions and decreased fetal weights).  The mammal
acute oral LD50 value (used in a preliminary analysis) is 37.5 mg/kg
(highly toxic). 

	E.  Data Gaps and Uncertainties  TC "E.  Data Gaps and Uncertainties"
\f C \l "2"  

		1. Environmental Fate and Exposure  TC "1. Environmental Fate and
Exposure" \f C \l "3"  

	The environmental fate data base for the parent compound provided
mostly supplemental information (Appendix F, Table A1-B). However, key
environmental fate studies such as aerobic soil metabolism and
photolysis in air have several deficiencies and problems. Therefore,
data related to these key environmental fate processes were also
obtained from open literature to complete the environmental fate and
exposure assessment.  The following environmental fate study was not
submitted, but is not needed for risk assessment. 

165-4  Bioaccumulation in fish of chloropicrin  The octanol/water
partition coefficient (Log Kow) for chloropicrin is 2.38, indicating a
low potential for chloropicrin to bioaccumulate in aquatic organisms. It
also photolyzed (t1/2= 1.3 days) in water rapidly. The bioaccumulation
in fish study is not required under these circumstances, according to
the Subdivision N guidelines.

Uncertainties

	

	There are uncertainties in estimating chloropicrin exposure in surface
water from post-application, due to tarping of the treated area.  If
tarping is used to minimize the volatilization of chloropicrin, the
loading of the chemical through runoff will be limited until the tarp is
sliced or removed from the field. The present version of the PRZM model
and the selected crop scenarios used in modeling have limited
capabilities in discounting the load from runoff of applied chemical
under a post-application tarp scenario. Since the load of chloropicrin
from runoff is considered in the PRZM/EXAMS simulation for tarped
scenarios, the estimated concentrations of chloropicrin in surface water
bodies may be upper bound.

	There are uncertainties with both existing monitoring and modeling of
air residues for the purpose of estimating exposure to terrestrial
wildlife.  Since field emission and air monitoring data of chloropicrin
were collected at various heights, actual concentrations at ground level
at the edge of the field may differ from estimated air concentration
using ISCTS3/PERFUM modeling and ambient air monitoring . Air monitoring
at ground-level of chloropicrin in the fumigated fields may reduce the
uncertainty related to terrestrial exposure for wildlife.

2. Ecological Effects  TC "2. Ecological Effects" \f C \l "3"   

	The following data are needed on chloropicrin for ecological risk
assessment.  These data needs are similar to those available or
previously specified as needed for risk assessment for methyl bromide
and for the degradate MITC as part of the metam-sodium risk assessment. 
Appendix E lists the status of the ecological effects data requirements
for chloropicrin. 

71-1 Avian Acute Oral.  The current estimate of avian risk is based
largely on the mammal assessment.  This basic study will contribute to a
risk assessment specific to birds.  It will 1) enable a comparison to
the mammal acute oral data and 2) enable the use of an EFED spreadsheet
to estimate avian acute inhalation toxicity based on the mammal acute
oral and inhalation data.

----- Avian acute inhalation.  The current estimate of avian risk is
based largely on the mammal assessment.  This study will enable an
inhalation risk assessment specific to birds.  Since the risk assessment
for terrestrial wildlife is focused on inhalation and this study will
provide actual inhalation data rather than an estimation based on acute
oral data, it is of even higher priority than the acute oral study.

-----Avian sub-chronic/chronic inhalation.  This study is needed for
risk assessment, due to the potential for repeat and/or continuous
exposure to birds resulting from the use of chloropicrin on multiple
fields over multiple days in any given geographic area.

870.1300.  Acute inhalation toxicity test – rat..  The existing study
(MRID 45117902) is classified by HED as Acceptable/Non-guideline.  The
7/25/00 DER and 1/31/05 Revised HED Human Health Risk Assessment state:
“The LC50 calculated for the study should not be considered to be a
true LC50 for chloropicrin.  Due to the sacrifice of all live animals at
day 3 of the study instead of day 14, and too large of exposure particle
sizes, the true LC50 could be lower.”  Thus, a new study will enable
an improved wild mammal risk assessment with reduced uncertainty. 
Please note that although EFED needs the results this study for risk
assessment, it is not listed in Appendix E since it is an HED guideline
and EFED does not review these studies.

72-1(a) and (c) Acute Fish Toxicity – bluegill and rainbow trout.  The
risk assessment is currently relying on supplemental data.  Flow-through
studies with measured concentrations will greatly reduce uncertainty.

72-2(a) Acute aquatic invertebrate toxicity.  The risk assessment is
currently relying on supplemental data.  Flow-through studies with
measured concentrations will greatly reduce uncertainty.

72-3(a) Acute Marine/Estuarine Fish. Given the use patterns of
chloropicrin, marine/estuarine species could be exposed.  This study
will enable a risk assessment specific for marine/estuarine species
exposure.

72-3(b) Acute Marine/Estuarine Mollusk.  Given the use patterns of
chloropicrin, marine/estuarine species could be exposed.  This study
will enable a risk assessment specific for marine/estuarine species
exposure.  It will also improve certainty with the endangered species
risk assessment, as this test species may be more representative of
endangered freshwater mussels than the freshwater Daphnia.

72-3 (c) Acute Marine/Estuarine Shrimp. Given the use patterns of
chloropicrin, marine/estuarine species could be exposed.  This study
will enable a risk assessment specific for marine/estuarine species
exposure.  One literature search toxicity value is available, but it is
from a static study without measured concentrations.

72-4(a) Early Life-stage Fish – Freshwater.  Current aquatic modeling
indicates the potential for chronic aquatic exposure to chloropicrin.
This study will enable a chronic risk assessment for freshwater fish.

72-4(a) Early Life-stage Fish – Marine/Estuarine.  Current aquatic
modeling indicates the potential for chronic aquatic exposure to
chloropicrin.  This study is reserved pending the submission and review
of the above early life-stage studies with a freshwater fish species.

72-4(b) Life-Cycle Aquatic Invertebrate.  Current aquatic modeling
indicates the potential for chronic aquatic exposure to chloropicrin. 
This study will enable a chronic risk assessment for aquatic
invertebrates.

72-5 Life-Cycle Fish. This study is reserved, pending submission and
review of early life-stage fish testing.

123-1(a) Seed Germination/Seedling Emergence – Tier II.  Chloropicrin
is used in part due to its phytotoxicity  at the application site, and a
wide range of open literature and other non-guideline studies indicate
the potential for plant damage.  This study will enable the assessment
of risk to non-target terrestrial plants off-site.

123-1(b) Vegetative Vigor – Tier II.  Chloropicrin has at least some
phytotoxicity on the treatment site, based on label and open literature
information.  This study will enable the assessment of risk to
non-target terrestrial plants off-site.

123-2 Aquatic Plant Growth – Tier II.   Chloropicrin has at least some
phytotoxicity on the treatment site, based on label and open literature
information.  This study will enable the assessment of risk to
non-target aquatic plants off-site. 

141-1 Honeybee Acute contact.  This basic study is now being requested
for virtually all outdoor uses, and will help determine the need for,
and specifics of, bee hazard labeling.

		Uncertainties

	There are substantial uncertainties concerning the ecological effects
of chloropicrin, in part due to the extremely limited data available for
risk assessment.  There are no studies considered fully acceptable for
any taxonomic group or time exposure, except for the mammal acute oral
and chronic inhalation data used. 

	The uncertainties associated with the risk to terrestrial organisms
from chloropicrin use  are mainly focused on the extent and effect of
terrestrial animal exposure via inhalation.  There is uncertainty with
the mammal acute inhalation toxicity, as indicated above.  Avian
inhalation toxicity data are not available at all, as also noted.  In
addition, the lack of avian acute oral data prevents an extrapolated
estimation of inhalation toxicity based on mammal data.  Terrestrial
plant data are needed to conduct an assessment of risk to non-target
terrestrial plants off-site.

	Because of the repeat exposures from applications to different fields
on different days in a given geographic area, there is the added
potential for chronic exposure.   Acute inhalation studies are typically
just 4 hours long.  A subchronic/chronic avian inhalation study will
enable EFED to address longer-term exposure to birds.

	The uncertainties associated with the risk to aquatic organisms from
chloropicrin are due to uncertainties over the length of exposure to
this highly volatile chemical and to uncertainties over the toxicity
(resulting mainly from the volatility).   However, both acute and
chronic exposure are possible, in part due to repeat or continuous input
to the aquatic environment.  Acute and chronic toxicity data are not
available for most fish and aquatic invertebrate guideline test
categories, freshwater or estuarine/marine.  The risk assessment relies
on supplemental data for freshwater fish and aquatic invertebrates. II.
 Problem Formulation  TC "II.  Problem Formulation" \f C \l "1"  

	A.  Stressor Source and Distribution  TC "A.  Stressor Source and
Distribution" \f C \l "2"  

		1.  Source and Intensity  TC "1.  Source and Intensity" \f C \l "3"  

	The source of the stressor considered in this ecological risk
assessment is the sole active ingredient chloropicrin, a pre-plant
fumigant used in controlling soil pathogens. Chloropicrin is a small,
single-carbon organic molecule that diffuses rapidly and volatilizes
from applied agricultural soils. The major source and mechanism of
release of chloropicrin is volatilization from the fumigated sites.
Additional transport mechanisms include runoff from pre-plant fumigated
fields, and drift of volatilized chloropicrin and redeposition through
precipitation in the adjacent area. The major breakdown products of
chloropicrin in soil and air is carbon dioxide. Since the degradation
products of chloropicrin are unstable in the environment, no metabolites
were considered in the risk assessment. 

		2.  Physical/Chemical/Fate and Transport Properties  TC "2. 
Physical/Chemical/Fate and Transport Properties" \f C \l "3"  

○C), high Henry’s Law Constant (2.05 * 10-3 atm M3/mole), and low
affinity for sorption on soil of chloropicrin suggest that
volatilization is the most important environmental route of dissipation.
Chloropicrin also undergoes rapid breakdown in soil, primarily via
microbial degradation as well as in the atmosphere through direct
photolysis. The relatively low Kow and high water solubility of the
parent suggests bio-concentration in aquatic organisms will be low. 

		3.  Pesticide Type, Class, and Mode of Action  TC "3.  Pesticide Type,
Class, and Mode of Action" \f C \l "3"  

	Chloropicrin is a fumigant used in pre-plant soil fumigation.
Chloropicrin’s specific mode of action is not understood, but it is a
strong irritant that is very toxic to all biological systems; affecting
body surfaces and interfering with the respiratory system and the
cellular transport of oxygen (U.S. Forest Service, 1995).	

		4.  Overview of Pesticide Usage  TC "4.  Overview of Pesticide Usage"
\f C \l "3"  

	Pre-plant soil use in agriculture accounts for most of the use of
chloropicrin. Chloropicrin can also be formulated in combination with
other fumigant to broaden its spectrum. In these combination end-use
products, the percent active ingredient for chloropicrin can range from
20 to 55% when combined with methyl bromide and from 15 to 60% when
combined with 1,3-D. Chloropicrin is typically applied once per growing
season through soil injection or drip irrigation to fumigate upper six
to twelve inches of soil as a liquid 14 days or more before planting.  

The maximum application rate being supported in reregistration is 350 lb
ai/A, with 300 lb ai/A the maximum for drip irrigation. The product is
also used as a warning agent for odorless fumigants. Individually,
strawberries, tobacco, tomatoes, and peppers were the crops with the
highest percentage of their overall acreage treated from 1998 to 2000.

		B.  Receptors  TC "B.  Receptors" \f C \l "2"  

		1.  Ecological Effects  TC "1.  Ecological Effects" \f C \l "3"  

	Each assessment endpoint requires one or more measures of ecological
effect, which are defined as changes in the attributes of an assessment
endpoint itself or changes in a surrogate entity or attribute in
response to exposure to a pesticide.  Ecological measures of effect for
the screening level risk assessment are usually based on a suite of
registrant-submitted toxicity studies performed on a limited number of
organisms in broad groupings listed in Table 1.  These laboratory test
organisms serve as surrogates for all nontarget animal and plant species
that could potentially be exposed to a given pesticide.

Table 1.  Examples of taxonomic groups and test species evaluated for
ecological effects in screening level risk assessments.

Taxonomic Group	Example(s) of Representative Species

Birds1	mallard duck (Anas playtrhynchos)

bobwhite quail (Colinus virginianus)

Mammals	laboratory rat

Freshwater Fish2	bluegill sunfish (Lepomis macrochirus)

rainbow trout (Oncorhynchus mykiss)

Freshwater Invertebrates	water flea (Daphnia magna)

Estuarine/Marine Fish	sheepshead minnow (Cypridodon variegatus)

Estuarine/Marine Invertebrates	Eastern Oyster (Crassostrea virginica) 

Mysid Shrimp (Americamysis bahia)

Terrestrial Plants3	Monocots - corn (Zea mays)

Dicots - soybean (Glycine max)

Aquatic Plants and Algae	duckweed (Lemna gibba) 

green algae (Selenastrum capricornutum)

1 Birds may be surrogates for amphibians (terrestrial phase) and
reptiles.

2 Freshwater fish may be surrogates for amphibians (aquatic phase).

3 Four species of two families of monocots, of which one is corn; six
species of at least four dicot families, of which one is soybeans.

	

	

Within each of these very broad taxonomic groups, an acute and/or
chronic endpoint is selected from the available test data. A complete
discussion of all toxicity data available for this risk assessment and
the resulting measures of effect selected for each taxonomic group are
included in Appendix C.  A summary of the potential assessment endpoints
and measures of effect selected to characterize potential ecological
risks associated with exposure to chloropicrin is provided in Table 2. 
However, data are not available for all potential measures of effect.

Table 2.  Summary of potential assessment endpoints and measures of
effect.

Assessment Endpoint

		Measures of Effect

1.	Abundance (i.e., survival, reproduction, and growth) of individuals
and populations of birds 	1a.	Bobwhite quail or mallard duck acute oral
LD50

1b.	Bobwhite quail and mallard duck subacute dietary LC50

1c.	Bobwhite quail or mallard duck acute inhalation LC50

1d.	Bobwhite quail and mallard duck chronic reproduction NOAEL and LOAEL

1e.	Bobwhite quail or mallard duck sub-chronic/chronic inhalation
toxicity

2.	Abundance (i.e., survival, reproduction, and growth) of individuals
and populations of mammals 	2a.	Laboratory rat acute oral LD50

2b.	Laboratory rat acute inhalation toxicity

2c.	Laboratory rat developmental and chronic (2-generation) NOAEL and
LOAEL

2d.	Laboratory mammal chronic inhalation NOAEL and LOAEL

3.	Survival and reproduction of individuals and communities of
freshwater fish and invertebrates 	3a.	Rainbow trout and bluegill
sunfish acute LC50

3b.	Rainbow trout chronic (early-life) NOAEL and LOAEL

3c.	Water flea (and other freshwater invertebrates) acute EC50

3d.	Water flea chronic (life-cycle) NOAEL and LOAEL

4.	Survival and reproduction of individuals and communities of
estuarine/marine fish and invertebrates 	4a.	Sheepshead minnow acute
LC50

4b.	Estimated chronic NOAEL and LOAEL values based on the
acute-to-chronic ratio for freshwater fish

4c.	Eastern oyster and mysid shrimp acute LC50

4d.	Mysid shrimp chronic (life-cycle) NOAEL and LOAEL 

4e.	Estimated NOAEL and LOAEL values for mollusks based on the
acute-to-chronic ratio for mysids

5.	Perpetuation of individuals and populations of  non-target
terrestrial and semi-aquatic species (crops and non-crop plant species)
5a.	Monocot and dicot seedling emergence and vegetative vigor EC25
values

6.	Survival of beneficial insect populations	6a.	Honeybee acute contact
LD50

7.	Maintenance and growth of individuals and populations of aquatic
plants from standing crop or biomass	7a.	Algal and vascular plant (i.e.,
duckweed) EC50 values for growth rate and biomass measurements 

LD50 = Lethal dose to 50% of the test population.

NOAEL = No observed adverse effect level.

LOAEL = Lowest observed adverse effect level.

LC50 = Lethal concentration to 50% of the test population.

EC50/EC25 = Effect concentration to 50%/25% of the test population.

		2.  Ecosystems Potentially At Risk  TC "2.  Ecosystems Potentially At
Risk" \f C \l "3"  

	Ecosystems potentially at risk are expressed in terms of the selected
assessment endpoints.  The typical assessment endpoints for
screening-level pesticide ecological risks are reduced survival, and
reproductive and growth impairment for both aquatic and terrestrial
animal species.  Aquatic animal species of potential concern include
freshwater fish and invertebrates, estuarine/marine fish and
invertebrates, and amphibians.  Terrestrial animal species of potential
concern include birds, mammals, beneficial insects, and earthworms.  For
both aquatic and terrestrial animal species, direct acute and direct
chronic exposures are considered.  In order to protect threatened and
endangered species, all assessment endpoints are measured at the
individual level, which may also provide insights regarding risks at
higher levels of biological organization (e.g., populations and
communities).  For example, pesticide effects on individual survivorship
can have important implications for both population growth rates and
habitat carrying capacity.  

	For terrestrial plants and plants in semi-aquatic environments, the
screening assessment endpoint is the perpetuation of populations of
non-target species, including crops and non-crop plant species. Existing
testing requirements focus on an evaluation of seedling emergence and
vegetative vigor. 

 The Agency recognizes that these endpoints may not address all
components of the lifecycle of plants in terrestrial and semi-aquatic
environments.  It is assumed that impacts at emergence and in active
growth stages can reduce a plant’s overall ability to be competitive,
ultimately impacting reproductive success. For aquatic plants, the
assessment endpoint is the maintenance and growth of standing crop or
biomass.  Measures of effect for these assessment endpoints include
growth rates and biomass measurements of algae and common vascular
plants (i.e., duckweed).  These receptors are useful indicators of risks
to the ecosystem for at least two reasons: 1) complete exposure pathways
exist for these receptors; and 2) they are ubiquitous, potentially
inhabiting areas where pesticides are applied, or areas where runoff
and/or spray drift may occur. 

	Specifically for chloropicrin, ecosystems potentially at risk would
include those in close enough proximity to treated fields to receive
either off-gassed chloropicrin transported via the air or chloropicrin
transported via ground or surface water.  Given the use of chloropicrin
in multiple states and regions across the U.S. (See Figure 2), this
could potentially include a wide variety of terrestrial and aquatic
ecosystems.

	C.  Assessment Endpoints  TC "C.  Assessment Endpoints" \f C \l "2"  

	Assessment endpoints are defined as “explicit expressions of the
actual environmental value that is to be protected.”  Defining an
assessment endpoint involves two steps: 1)  identifying the valued
attributes of the environment that are considered to be at risk; and 2)
operationally defining the assessment endpoint in terms of an ecological
entity (i.e., a community of fish and aquatic invertebrates) and its
attributes (i.e., survival and reproduction).  Therefore, selection of
the assessment endpoints is based on valued entities (i.e., ecological
receptors), the ecosystems potentially at risk, the migration pathways
of pesticides, and the routes by which ecological receptors are exposed
to pesticide-related contamination.  The selection of clearly defined
assessment endpoints is important because they provide direction and
boundaries in the risk assessment for addressing risk management issues
of concern.  Potential assessment endpoints and measures of effect are
described in Table 2.

	D.  Conceptual Model  TC "D.  Conceptual Model" \f C \l "2"  

		1.  Risk Hypotheses  TC "1.  Risk Hypotheses" \f C \l "3"  

	Risk hypotheses are specific assumptions about potential adverse
effects (i.e., changes in assessment endpoints) and may be based on
theory and logic, empirical data, mathematical models, or probability
models (USEPA 1998a).  For this assessment, the risk is
stressor-initiated, where the stressor is the release of chloropicrin to
the environment.  The following risk hypothesis is presumed for this
screening level assessment:

Based on the toxicity, the high application rates, the volatility, and
the environmental fate and mode of action of chloropicrin, as well as
the exposed aquatic and terrestrial ecosystems, chloropicrin has the
potential to cause reduced survival, and reproductive and growth
impairment for both aquatic and terrestrial animal and plant species.

	Adequate protection is defined as protection of growth, reproduction,
and survival of aquatic and terrestrial animal and plant populations,
and individuals of threatened and endangered species, as needed.

		2.  Diagram  TC "2.  Diagram" \f C \l "3"  

		

	The conceptual site model is a generic graphic depiction of the risk
hypothesis, and assumes that as a fumigant with a toxic mode of action,
chloropicrin is capable of affecting terrestrial and aquatic organisms
provided that environmental concentrations are sufficiently elevated as
a result of proposed label uses.  However, through a preliminary
iterative process of examining fate and effects data, the conceptual
model, i.e., the risk hypothesis, has been refined to reflect the likely
exposure pathways and the organisms that are most relevant and
applicable to this assessment (Figure 1). It includes the potential
pesticide or stressor (chloropicrin), the source and/or transport
pathways, abiotic exposure media, exposure point, biological receptor
types, and attribute changes.

	In order for a chemical to pose an ecological risk, it must reach
ecological receptors in biologically significant concentrations.  An
exposure pathway is the means by which a contaminant moves in the
environment from a source to an ecological receptor.  For an ecological
exposure pathway to be complete, it must have a source, a release
mechanism, an environmental transport medium, a point of exposure for
ecological receptors, and a feasible route of exposure.  In addition,
the potential mechanisms of transformation (i.e., which degradates may
form in the environment, in which media, and how much) must be known,
especially for a chemical whose metabolites/degradates are of greater
toxicological concern than the parent compound. The assessment of
ecological exposure pathways, therefore, includes an examination of the
sources and potential migration pathways for constituents, and the
determination of potential exposure routes (e.g., ingestion, inhalation,
dermal absorption).



	The source and mechanism of release of chloropicrin are volatilization,
drift and runoff from pre-plant fumigated fields for agricultural crops.
 Surface water runoff from the areas of application is assumed to follow
topography. Additional transport mechanisms include drift of volatilized
chloropicrin as well as redeposition through precipitation to the
surrounding areas.  Chloropicrin exposure to terrestrial animals is
expected primarily through inhalation of chloropicrin and to a lesser
extent by ingestion of contaminated food items such as grass and foliage
contaminated from atmospheric redeposition.  Exposure from redeposition
of volatilized chloropicrin via precipitation in terrestrial environment
is expected to be negligible, due to the short direct photolytic
half-life ((t1/2 <8 hrs) of chloropicrin in the atmosphere. Thus, the
exposure from redeposition of chloropicrin via precipitation was not
considered in this assessment. 

	Ecological receptors that may potentially be exposed to chloropicrin
include terrestrial and semi-aquatic wildlife (i.e., mammals, birds, and
reptiles), terrestrial plants and plants in semi-aquatic areas, and soil
invertebrates.  In addition to terrestrial ecological receptors, aquatic
receptors (e.g., freshwater and estuarine/marine fish and invertebrates,
amphibians) may also be exposed to potential migration of pesticide from
the site of application to various watersheds and other aquatic
environments via runoff and drift of volatilized material. For aquatic
receptors, the major point of exposure is through direct contact with
the water column, sediment, and pore water (gill/integument)
contaminated with spray drift and/or runoff from treated areas. 
However, indirect effects to aquatic organisms (especially fish) can
also occur through impact to various food chains.

	There are substantial uncertainties concerning the ecological effects
of chloropicrin, in part due to the extremely limited ecotoxicity data
available.  There are no studies considered fully acceptable for any
taxonomic group or time exposure, except the mammal acute oral and
chronic inhalation data used. Therefore, the evaluation of risk to
various taxonomic groups is based on very limited toxicity data.

	E.  Analysis Plan  TC "E.  Analysis Plan" \f C \l "2"   

	1. Preliminary Identification of Data Gaps and Methods  TC "1.
Preliminary Identification of Data Gaps and Methods" \f C \l "3"  

	The analysis plan is the final step in Problem Formulation and targets
the working hypotheses that are considered more likely to affect the
assessment endpoints. The Analysis Plan specifies the data that is
required in developing an evaluation of the potential impact of a
pesticide to the assessment endpoints and the methods that will be used
to analyze the data. The Analysis Plan is also used to outline the scope
of the assessment, identify the measures of effect to be used in
evaluating the hypothesis, and a rationale for the focus and possible
refinement of the assessment.

	The objective of EFED’s risk assessment is to identify the risk to
the environment from chloropicrin use as a soil fumigant in agricultural
crops.  This initial analysis will be referred to as Tier I screening
and is based on the ratio or quotient method. As noted in the USEPA
1998, Part A Section 5.1.3, “Typically, the ratio (or quotient) is
expressed as an exposure concentration divided by an effects
concentration”. Therefore the risk quotient (RQ) is the ratio of the
estimated environmental concentration (EEC) of a chemical to a toxicity
test effect (e.g., LC50 ) for a given species. The RQ as an index of
potential adverse effects is then compared to an Agency established
Level of Concern (LOC) in order to identify when the potential adverse
effect is a concern to the Agency. These LOCs are the Agency’s
interpretive policy and are used to analyze potential risk to non-target
organisms and the need to consider regulatory action. Appendix D of this
document summarizes the LOCs used in this risk assessment. This paper
presents a sequence of risk assessment methods that include PRZM/EXAMS
generated EEC values for aquatic exposure and ISCTS3 model simulated air
residue values for terrestrial wildlife exposure. The laboratory-derived
effects data for the most sensitive representative species of
terrestrial and aquatic organisms are included in Tables 9 and 10.  This
screening-level assessment should identify habitats, and species
potentially at risk from chloropicrin exposure. The fate, effects, and
usage information presented in this document suggest that the focus of
the working hypothesis for an environmental risk assessment is that
exposure to chloropicrin has the potential to cause acute and chronic
effects that may result in reduced survival, reproductive impairment and
growth effects to aquatic and terrestrial animals and plant species.

	  Data Gaps

The adequacy of the submitted data was evaluated relative to Agency
guidelines.  The following identified data gaps for ecological fate and
effects endpoints result in a degree of uncertainty in evaluating the
ecological risk of chloropicrin. 

No data are available to assess the acute or chronic risk of
chloropicrin to birds.

No data are available to assess the chronic risk of chloropicrin to
freshwater or estuarine/marine fish.

No data are available to assess the chronic risk of chloropicrin to
freshwater or estuarine/marine invertebrates.

No data are available to assess the risk of chloropicrin to terrestrial,
aquatic, or semi-aquatic plants.

The mammal acute inhalation study reviewed by HED has deficiencies and
is considered non-guideline.

Studies available on the effects of chloropicrin to freshwater fish and
aquatic invertebrates are considered supplemental.  

		2.  Measures to Evaluate Risk Hypotheses and Conceptual Model  TC "2. 
Measures to Evaluate Risk Hypotheses and Conceptual Model" \f C \l "3"  

			a.  Measures of Exposure  TC "a.  Measures of Exposure" \f C \l "4"  

	Exposure concentrations for aquatic ecosystems were estimated based on
the Tier 2 aquatic model Pesticide Root Zone Model (PRZM; Carsel, et
al., 1998) and Exposure Analysis Modeling System (EXAMS; Burns, 2002). 
PRZM (version 3.12.2, May 2005) simulates the fate of the chemical in
the field, including runoff and erosion on a daily time step, and EXAMS
(version 2.98.4.6, April 2005) simulates the environmental fate and
transport processes in a body of surface water. A graphical user
interface (pe5v01.pl, August 2007), developed by the USEPA, 2004 was
used to facilitate the input of chemical, fate, and use specific
parameters into the appropriate PRZM and EXAMS files. PRZM/EXAMS model
simulates are run for multiple (usually 30) years and reported estimated
environmental concentration (EEC) are the concentrations that are
expected once in every ten years based on the thirty years of daily
values generated by the simulation. The critical measure of exposure for
a Tier 1 acute aquatic risk assessment is the peak EEC in surface water.
 For chronic aquatic assessments, the 21-day average EEC is typically
used for aquatic invertebrates and the 60-day average is now typically
used for fish (both embryo-larvae and full lifecycle). 

ated maximum concentration of 0.019 mg/L (19037 μg/m3) was used in
calculating inhalation exposure for terrestrial organisms.

			b.  Measures of Effect  TC "b.  Measures of Effect" \f C \l "4"  

	Measures of effect are generally based on the results of a toxicity
study, although monitoring data and incident reports may also be used to
provide supporting lines of evidence for the risk characterization.  A
complete summary of the potential measures of effect based on toxicity
studies for different ecological receptors and effect endpoints
(acute/chronic) is given in Table 2 above.  Examples of measures of
acute effects (e.g., lethality) include an oral LD50 for mammals and
LC50 for fish and invertebrates.  Examples of measures of chronic
effects include a NOAEL for birds or mammals based on reproduction or
developmental endpoints, and an EC05 for plants based on growth rate or
biomass measurements.

			c.  Measures of Ecosystem and Receptor Characteristics  TC "c. 
Measures of Ecosystem and Receptor Characteristics" \f C \l "4"  

	For the Tier 1 assessment, the ecosystems that are modeled are intended
to be generally representative of any aquatic or terrestrial ecosystem
associated with areas where chloropicrin is used.  The receptors
addressed by the aquatic and terrestrial risk assessments are summarized
in Figure 1.  For aquatic assessments, generally fish, aquatic
invertebrates, and aquatic plants in both freshwater and
estuarine/marine environments are represented.  For terrestrial
assessments, generally birds, terrestrial plants, and wild mammals are
included. 

III.  Analysis  TC "III.  Analysis" \f C \l "1"  

	A.  Use Characterization  TC "A.  Use Characterization" \f C \l "2"  

	Chloropicrin is a broad-spectrum fumigant used for the control of
weeds, nematodes, insects, rodents, and certain fungi. Chloropicrin
end-use products are packaged as 100% chloropicrin formulations as well
as in combination formulations with methyl bromide and 1,3-D.  In these
combination end-use products, the percent active ingredient for
chloropicrin can range from 20 to 55% when combined with methyl bromide
and from 15 to 60% when combined with 1,3-D.

	 Chloropicrin is registered for pre-plant soil fumigation of field to
be planted with a wide variety of food, ornamental, and nursery crops.
Typical use consists of making one application per year prior to
planting a crop or multiple crops in the fumigated field. Individually,
strawberries, tobacco, tomatoes, and peppers were the crops with the
highest percentage of their overall acreage treated from 1998 to 2000. 
The average annual percent crop treated for those crops, respectively,
were 20, 15, 10, and 10 percent while the maximum percent crop treated,
respectively, for those crops was 50, 20, 45, and 30 percent. Crops that
use over a million pounds annually of chloropicrin in their production
include tobacco (3.6 million pounds), tomatoes (1.7 million pounds), and
strawberries (1.4 million pounds). Figure 2 shows the average pounds of
active ingredient was applied in various states for all surveys crops
based on three years (2002 to 2004) of EPA data (USEPA 2005a). 

	In general, two most frequent options of chloropicrin application
methods include shank injection (soil injection) followed by tarping and
drip irrigation (chemigation) under a pre-tarped soil surface.
Chloropicrin can also be applied using shank injection and drip
irrigation without tarping. Non-tarp shank injection application
requires lower rate (≤175 lbs/acre) of chloropicrin, possibly due to
requirements for worker protection. For drip irrigation, non-tarp
chloropicrin application in soil requires the placement of drip tubing
at a minimum depth of 5 inches from surface. Post application sealing
methods like tarping, water sealing, and compacting soil surface are
fumigant management practices followed immediately after fumigation to
contain the applied chloropicrin and reduce its diffusion into the
atmosphere.

	The Chloropicrin Manufacturer’s Task Force (CMTF) members have
amended the four existing manufacturing labels to use in delete use of
chloropicrin as an active ingredient in pesticide formulations for
post-harvest uses, structural fumigations, forestry uses, and aquatic
use patterns.  The CMTF is supporting pre-plant soil fumigation use in
agricultural fields and commercial greenhouses. In addition to this
labeling change, CMTF is supporting the following maximum rates for
pre-plant soil fumigation use in agricultural field.

350 lbs per treated acre for shank injection applications - tarped;

175 lbs per treated acre for shank injection applications - untarped;

300 lbs per treated acre for drip irrigation applications.

   HYPERLINK \l Generated Bookmark30  Figure 2. Average annual pounds of
active ingredient of chloropicrin was applied by state for all surveyed
crops based on three years of EPA data (2002-2004).

	There are some current chloropicrin labels that have higher maximum
application rates but CMTF has not conducted studies to support these
higher rates. At this time, the assessment reflects these new maximum
rates. Other registrants wishing to support higher rates must conduct
the appropriate studies and submit them to the Agency.

	Chloropicrin is also used as an odorant when it is added to methyl
bromide (for pre-plant soil fumigation) and sulfuryl fluoride (indoor
fumigation) formulations at 2% by weight or less.  When used in this
capacity, chloropicrin is not used as an active ingredient but as a
warning  agent to indicate possible hazardous concentrations of odorless
methyl bromide or sulfuryl fluoride vapors.

B.  Exposure Characterization  TC "B.  Exposure Characterization" \f C
\l "2"  

		1.  Environmental Fate and Transport Characterization  TC "1. 
Environmental Fate and Transport Characterization" \f C \l "3"    TC "1.
 Environmental Fate and Transport Characterization" \f C \l "3"  

	Chloropicrin is a clear, colorless, nonflammable oily liquid with
strong, sharp, highly irritating odor and a strong lacrimator. Selected
physic-chemical and environmental fate properties of chloropicrin are
listed in Table 3 and 4. The high vapor pressure (23.8 mm @ 25○C),
high Henry’s Law Constant (2.05 X 10-3 atm M3/mole), and low soil
adsorption coefficient (Koc 36.05 L kg-1) on soil of chloropicrin
suggest that volatilization is the most important environmental route of
dissipation. Direct photolytic degradation (t1/2 <8 hrs) of chloropicrin
is the primary route of dissipation in the atmosphere, which suggest it
is not a significant threat to deplete stratosphere ozone layer. Due to
the fact that volatilization is significant and occurs rapidly, the
importance of other competing processes such as leaching, biotic and
abiotic degradation, and adsorption to the soil particles will certainly
depend on chloropicrin emission rate from fumigated fields. This is
because emission rate determines the amount of chloropicrin left for
other processes and its residence time in the soil system. However, if
chloropicrin remains in soil, it also degrades in soil with half-lives
ranges from 3.7 to 4.5 days with CO2 being the terminal breakdown
product. Since chloropicrin is highly soluble in water and has low
adsorption in soil, it can potentially leach into groundwater and to
surface water through runoff under a flooded condition. The low
octanol/water partition coefficient of chloropicrin also indicates that
it is not likely to be bioconcentrated in tissues of aquatic organisms. 

 

	PC Code	081501

	CAS number	76-06-2

	Common name	Chloropicrin

	SMILES Notation	N(=O)(=O)C(CL)(CL)CL

	Molecular formula	CCl3NO2	MRID# 43613901

Molecular weight	164.38 g/mol	MRID# 43613901

IUPAC name	trichloronitromethane	Merck Index

CAS name	trichloronitromethane	Merck Index

Physical State	Near colorless, oily liquid	Merck Index

Melting point/range	-69.2○C	Merck Index

Boiling point/range	112○C at 757 mm Hg	Merck Index

Density	1.7 g/mL at 25○C	Merck Index

Water solubility	1.612 g/L at 25○C	MRID# 43613901

Vapor pressure	23.8 mm Hg at 25○C 	Merck Index

Henry’s Law Constant@ 25oC	2.05 * 10-3 atm•m3/mole	Kawamoto and
Urano, 1989

Octanol/water partition coefficient (Log KOW)	2.38	Kawamoto and Urano,
1989

≤8.0 Hours

20 days

phosgene (COCl2), nitrosyl chloride (NOCl), nitrous oxide (NO), and
chlorine (Cl2); subsequently nitrogen dioxide (NO2) and dinitrogen
tetraoxide (N2O4)	Carter et al., 1997

MRID# 05007865

Soil metabolism	Aerobic t1/2

	4.5 days

3.7 days (soil)

4.4 days (total system)

major degradate is CO2

minor degradates (total <6%) chloronitromethane, nitromethane, and
bicarbonate	Wilhelm et al., 1996

MRID# 43613901

Aquatic metabolism  Anaerobic t1/2	0.3 days

Non-tarped soil maximum volatility 342 μg/cm2/hr; 

Tarped soil maximum volatility 

205 μg/cm2/hr	MRID# 43798601

	Field Dissipation

Terrestrial Field Dissipation	≤1.0 days 	MRID# 43085101

Aquatic Field Dissipation	N/A	Waived

	Bioaccumulation

Accumulation in Fish, max. BCF	N/A	Waived

(a) Fate and Transport in soil and water  TC "(a) Fate and Transport in
soil and water" \f C \l "4"  

	The dissipation of chloropicrin in aquatic and terrestrial environments
appears to be predominantly dependent on volatilization and to a lesser
extent on leaching and degradation. The high vapor pressure and the high
Henry’s Law Constant suggests that chloropicrin will volatilize from
soil and water. Once it volatilized, chloropicrin degrades rapidly into
CO2 and other metabolites in the atmosphere via direct photolysis. The
importance of other competing processes such as leaching,
biodegradation, and adsorption to the soil particles will certainly
depend on chloropicrin emission rate from the fumigated fields. This is
because emission rate determines the amount of chloropicrin left for
other processes and its residence time in the soil system. The
biodegradation half-lives of chloropicrin in soil is 3.7 days with
carbon dioxide being the terminal breakdown product (MRID 43613901).
Because of the volatile nature of chloropicrin, the half-life for the
total system was also calculated. The half-life for the total system was
4.4 days. Also, a cursory review of literature data (Wilhelm et al.,
1996, Gan et al., 2000) shows that major metabolic pathways occurs
through successive reductive dehalogenation of chloropicrin to
nitromethane:

→  HCCl2NO2  → H2CClNO2 →  H3CNO2  → CO2 

	Degradation of chloropicrin in soil follows first-order kinetics.
Wilhelm et al.(1996) estimated the half-life of 4.5 days for
chloropicrin in sandy loam soil with a rate equivalent to 500 lbs/Acre
following the Agency’s Pesticide Assessment Guidelines. Gan et al.
(2000) estimated that microbial degradation accounted for 68 to 92
percent of the overall degradation of applied chloropicrin. Gan et al.,
2000 also reported shorter half-lives than other studies. The study did
not report whether a trap was used to collect volatile chemicals, and
material balance was not reported. Based on the study limitations and
incomplete material balance, EFED can not confirm the estimated
degradation half-lives for various soil. 

	Chloropicrin is highly soluble in water and weakly retained by soil.
The supplemental terrestrial field dissipation studies (MRID 43085101)
were conducted in California, applying chloropicrin to bare fallow soils
at a rates of 665 lbs and 792 lbs a.i/acre through chisel injection
followed by tarping for 48 hours. The calculated field dissipation
half-lives were less than 21.7 hours. Volatilization of chloropicrin
from applied fields may have resulted in short half-lives in the field
dissipation study. Concentrations of chloropicrin at the 24-, 36-, and
48-inch depths increased to a maxima of 593.0, 230.5, and 75.2 ppm,
respectively; times of maximum concentration were 12, 24, and 48 hours,
respectively, after removal of the tarp.

	 The high Henry’s Law Constant (2.05 X 10-3 atm M3/mole) and rapid
photohydrolysis of chloropicrin suggest that volatilization and rapid
degradation are the primary environmental routes of dissipation from
surface water. The calculated half-life of 31.1 hours for in aqueous
solution (pH 7) when irradiated with xenon light source forming carbon
dioxide, chloride, nitrate and nitrite (MRID 42900201). In the absence
of light, chloropicrin did not hydrolyzed in sterile aqueous buffered
solution under acidic to alkaline pH (MRID 43022401). 

	Soil adsorption coefficient (Koc) of chloropicrin cannot be estimated
from the batch equilibrium study. Due to the rapid volatilization of
chloropicrin, it is unlikely that an equilibrium of chloropicrin in the
batch equilibrium will be reached. The Koc of chloropicrin was estimated
using the EPA’s computer model PCKOCWIN v1.66 of EPISUITE. EPI's Koc
estimations are based on the Sabljic molecular connectivity method. The
estimated Koc of chloropicrin is 36.05 ml/g. Chloropicrin’s high water
solubility (1621 mg/L) and low Koc of 36.05 ml/g suggest its high
mobility in the environment. The high solubility and low soil absorption
of chloropicrin can result in movement of it downward to groundwater
with water infiltration under an intense rainfall or continuous
irrigation right after chloropicrin application. A supplemental leaching
study (MRID 44191301) demonstrated that chloropicrin was very mobile in
all four soils.

		(b) Fate and Transport in atmosphere  TC "(b) Fate and Transport in
atmosphere" \f C \l "4"  

	  In a review of the environmental fate of chloropicrin, Kollman 1990,
noted that chloropicrin was likely to have relatively short persistence
in the atmosphere. Chloropicrin was found to be susceptible to direct
photolytic degradation in air. Laboratory simulation of exposure to
artificial sunlight found that it degraded with a half-life of 20 days
(MRID 05007865, Moilanen et al. 1978).  However, a later study using a
light source that better simulated the spectral intensity of sunlight
found chloropicrin to photolyze much more rapidly, with an estimated
atmospheric half-life of 3.4 to 8 hours in direct sunlight (Carter et
al., 1997), leading to an estimate of 1 day for its atmospheric
lifetime. 

The major degradation products were phosgene (carbonyl chloride) and
nitrosyl chloride, which rapidly photolyzes to reactive products NO and
Cl• (Carter et al., 1997). Continued oxidation of the chloropicrin
photolysis products would eventually produce CO2, NO2, N2O4, and Cl2
(Ecotoxnet 2001).  Phosgene has been detected in air downwind from a
field application of chloropicrin (Woodrow et al. 1983), consistent with
the results of laboratory photodegradation studies.

	Although chloropicrin has significant aqueous solubility, its high
vapor pressure results in limited partitioning into water; thus its
Henry’s Law Constant, 2.05 x 10-3 atm m3/mol is comparable to that of
long lived atmospheric vapors such as elemental mercury. Washout by
rainfall would occur, but not at a rate likely to cause a significant
reduction in the atmospheric half life of chloropicrin estimated from
direct photodegradation.  Similarly, uptake and subsequent degradation
in soils and oceans would occur, but rates of these processes would
likely be limited by atmospheric delivery to the soil or water
interface, and hence approximate rates estimated for methyl bromide
(Shorter et al. 1995, Yvon and Butler 1996).

 ‛total lifetime’ is computed from estimates of lifetimes computed
from photodegradation, oceanic uptake and terrestrial uptake:

1/τtotal = 1/τp + 1/τo + 1/τs         			 (1)

where  τp, is the atmospheric lifetime associated with processes of
direct and indirect photo and

chemical degradation and precipitation scavenging; and  τo ,and τs are
lifetimes associated with uptake by oceanic and terrestrial surfaces,
respectively.

	The atmospheric lifetime of chloropicrin in the atmosphere was
estimated to be 1 day (0.0027 years), based on the published
photodegradation rate (Carter et al., 1997). If atmospheric lifetimes of
2.7 and 3.4 years are assumed for oceanic and terrestrial uptake and
degradation processes (from methyl bromide), the estimate of atmospheric
lifetime for chloropicrin remains 0.0027 years.

	The highly toxic gas phosgene (once used as a chemical warfare agent)
is a major photodegradation product of chloropicrin.  Phosgene is
resistant to both direct and indirect photochemical degradation
processes in the atmosphere (Grosjean 1991; Helas and Wilson 1992), but
it is extremely reactive with water, hydrolyzing rapidly to carbon
dioxide and hydrochloric acid (Manoque and Pigford 1960). The dominant
process removing phosgene from the atmosphere is its reaction with
liquid water droplets (fog, clouds, and rain), with a tropospheric
lifetime estimated at 10 hours to 1 day (Manoque and Pigford 1960). 

 

Despite its short atmospheric half life, phosgene has been commonly
detected in air, especially in urban/industrial areas, with typical
concentrations of 80 to 130 ng/m3 (WHO 1998). Phosgene is a widely used
precursor in the chemical industry, with 3 x 106 metric tons produced
and used annually (WHO 1998). Phosgene is also formed in the atmosphere
by the photochemical oxidation of chloroethylenes, with generation rates
estimated to be 350,000 metric tons annually (Singh 1976). Phosgene
generation by conversion of 100% of chloropicrin used agriculturally in
the U.S. would amount to about 6000 metric tons annually (based on U.S
usage of 9000 metric tons/year (NASS 2005). Even with such unrealistic
conversion assumptions, chloropicrin usage appear to be a minor source
of atmospheric phosgene relative to other sources.

	Nitrosyl chloride is also produced in the photolysis of chloropicrin.
This highly toxic gas is both photoreactive and readily hydrolyzed, and
is estimated to have an atmospheric lifetime of less than 1 hour (Scheer
et al. 1997). 

	The reactive byproducts of chloropicrin photolysis, in particular
chlorine free radicals and NOx, could lead to the generation of
tropospheric ozone, although its potential (on a per molecule basis) for
contributing to the generation of ozone in polluted urban atmospheres is
no greater than the typical organic air pollutants contributing to the
problem (Carter et al., 1997).

	(c) Ozone Depletion Potential  TC "(c) Ozone Depletion Potential" \f C
\l "4"  

	The United Nations Industrial Development Organization listed
chloropicrin as a non-ozone depleting alternative fumigant (UNIDO 2003).
 The ozone depletion potential (ODP) of methyl bromide was calculated by
USEPA (USEPA, 2005)  as 0.38 using an approach published in WMO 2002. In
that approach, ODP is estimated by:

			ODP(x) =FRF*α*τx/τCFC-11*MCFC-11/Mx*nx/3          		 (2)

	where FRF is the fractional release factor that describes the
availability of a halogen for release from substance x relative to
CFC-11, alpha is the efficacy of a halogen relative to chlorine at ozone
destruction, and τ is the atmospheric lifetime or turnover time, M is
molecular weight, and nx is the number of halogen in a molecule of x.
Using the FRF for methyl bromide (Agency was unable to find a value for
chloropicrin), the ODP for chloropicrin is calculated as:

		ODP(chloropicrin) = [1.12*1*(0.0027/45)*137.7]/[164.4*(3/3)]	(3)		 

=5.6*10-5         		

	With an ozone depletion potential more than four orders of magnitude (
5.6*10-5  versus 0.38) less than methyl bromide, stratospheric ozone
depletion will not be a concern with the use of chloropicrin as a
fumigant.

		2.  Measures of Terrestrial Exposure  TC "2.  Measures of Terrestrial
Exposure" \f C \l "3"  

			(a)Terrestrial Exposure Modeling  TC "(a)Terrestrial Exposure
Modeling" \f C \l "4"  

	 To determine terrestrial exposure of chloropicrin, a deterministic
approach was used in estimating exposures around the treated fields.
This deterministic approach is based on 

monitoring data of chloropicrin and the use of the EPA’s Industrial
Source Complex: Short-Term Model (ISCST3) air dispersion model developed
by USEPA (U.S.EPA, 1995). ISCST3 is a steady-state Gaussian plume model,
which can be used to assess pollutant concentrations from a wide variety
of sources. The ISCST3 model is a publically vetted tool that is
currently used by the Agency’s Office of Air for regulatory decision
making.  A number of support documents for this tool can be found at the
Agency’s website Technology Transfer Network Support Center for
Regulatory Air Models (  HYPERLINK
(http://www.epa.gov/scram001/tt22.htm#isc.
http://www.epa.gov/scram001/tt22.htm#isc. ) The ISCST3 has been used
successfully to simulate fumigant levels in air following the fumigation
of warehouses and agricultural fields located in California (Barry et
al. 1997). ISCST3 provides useful results because it allows estimation
of air concentrations based on changing factors such as application
rates, field sizes, downwind distances, wind and weather conditions, and
other factors. Using this model for the soil fumigants allows EPA to
predict off-site movement given fixed meteorological and other
conditions.

	The modeling approaches used by the Agency were based on 24 hours
exposure intervals (i.e., 24 hours time-weighted average of monitored
air concentration of chloropicrin). Field sizes includes 1-, 5-, 10-,
20-, and 40 acre squares to represent a cross section of the fields that
might be fumigated for agriculture use. ISCST3 was used in estimating
air concentration using field emission ratio (ratio of the flux rate to
the application rate), various sized fields, methods of chloropicrin
placement, and different meteorological conditions. The basic approaches
to estimate air concentrations using ISCST3 model are outlined in the
Health Effects Division’s Draft Standard Operating Procedures (SOPs)
for Estimating Bystander Risk from Inhalation Exposure to Soil Fumigant
(USEPA,2004). ISCST3 estimated downwind air concentrations using hourly
meteorological conditions that include the wind speed and atmospheric
stability.

	In this assessment, one set of computations was completed using ISCST3
model at varying acreage and atmospheric conditions. The lower the wind
speed and more stable the atmospheric environment, the higher the air
concentrations were observed near the treated areas. The outputs were
then scaled to appropriate emission ratios and application rates
assuming stable weather condition, Table 5 reflects a wide variety of
application rates and methods as well as the estimated  concentrations
of chloropicrin in air at the edge of a 40 acres field size under stable
weather condition. The estimated maximum concentration of 0.019 mg/L
(19037 μg/m3) was used in calculating inhalation exposure for
terrestrial organisms. California fumigant Permit conditions and
detailed input assumptions and model results were described in the
HED’s Draft Chapter on Non-Occupational Risks Associated with
Chloropicrin (USEPA, 2005c).

	The specific inputs for the ISCST3 model calculations drove the
associated uncertainties in the results. For example, the key input
factors for pre-plant agricultural uses were field size, flux/emission
rates, atmospheric stability, and windspeed.  Wind direction is another
factor 

which also should be considered. The field sizes used by the Agency in
this assessment were 1 to 40 acres which is well within the range of
what could be treated on a daily basis. 

There are uncertainties associated with point estimates of flux/emission
rates for specific application techniques which is another varying
factor. The flux rates which were used have been calculated by the
Agency and they compare reasonably well with those calculated by the
study investigators.  The reality is that there is a large distribution
of flux rates which is a phenomena inherent in the nature of these types
of data.

Table 5. ISCTS3 estimated air concentrations of chloropicrin at various
distances from the edge of 40 acres fumigated fields (meter) under
several application methods

Application Methods	Tarping	Application Rate 

(lbs/Acre)	Concentraton Chloropicrin  in Air ( μg/m3)

	0 M*	25 M	50 M	100 M

Shank Injection Broadcast	Yes	350	19037	10951	8915	6876

Shank Injection Broadcast	No	175	15864	9126	7429	5730

Shank Injection Raised Bed	Yes	350	11319	6511	5301	4088

Shank Injection Raised Bed	No	175	11491	6610	5381	4150

Drip Irrigation	Yes	300	4373	2515	2048	1580

* Distances (meter) from the edge of the field

	The values used for this assessment yield conservative air
concentration estimates because considering a constant flux rate does
not allow for diurnal/nocturnal changes that may occur, which when
coupled with the appropriate wind speed and stability category, can
result in lower concentrations. The meteorological inputs also will
provide a conservative estimate of exposure because the wind direction
is considered to be perpendicular (pointed downwind) to the treated
field for the entire 24 hours represented in the calculation.  This is
not a normal situation in the atmosphere for most locations. There is
normally a prevailing wind with directional changes over the course of a
typical day, especially when diurnal and nocturnal differences are
noted. Overall, Agency believes that the approach used to evaluate
potential exposures from a known area source can be considered
conservative. It is believed, however, that the range of selected input
values and outputs represent what could reasonably occur in agriculture
given proper field and climatological conditions.

		(b) Terrestrial Exposure Monitoring Data  TC "(b) Terrestrial Exposure
Monitoring Data" \f C \l "4"  

	The short atmospheric lifetime indicate that readily detectable
concentrations of chloropicrin should not accumulate in the atmosphere.
A rough estimate of the steady-state tropospheric concentration that
would be attained for release of 9000 metric tons/year (US annual usage
in 2002, (NASS 2005)) to the atmosphere can be calculated by:

Input = Removal 

τchloropicrin)*volume of troposphere*steady state [chloropicrin]air    
          		  (4)

rearranged to:Steady State [chloropicrin]air = Input(moles/y)/ (volume
of troposphere(1.6 x 1020 moles)*1/τchloropicrin) and yielding:

Steady State [chloropicrin]air = 5.5X107 moles/y/( 1.6x1020
moles*1/0.0027 y)

= 9.28 x 10-16 mole fraction

 = 9.28 x 10-4 ppt 

=6.24 x 10-3 ng/m3

	If much of chloropicrin added to soils is degraded within the soil and
not volatilized, an even lower steady state concentration would be
expected.

	Background concentrations (concentrations in air at sites remote from
areas of recent application) of chloropicrin in air were below the
analytical detection limit (30 ng/m3) based on upwind or off target
monitoring by the California Air Resources Board (CARB 2004, 2003). 
Thus, as predicted by its short atmospheric half life, the detection and
measurement of chloropicrin in air is largely a local phenomenon.
Measured concentrations would be expected to vary greatly with time and
distance from areas of application, and with size and application rates
of the areas receiving treatment. 

	In monitoring conducted in urban and rural communities near
agricultural sites where chloropicrin was being applied in Monterey and
Santa Cruz Counties, the California Air Resources Board observed
concentrations of chloropicrin to range from undetected (<30 ng/m3) to
14000 ng/m3, with a range of 8-week average concentrations of 406 to
2270 ng/m3.  Chloropicrin was undetected in only 7 of 192 samples (CARB
2004). Similar monitoring in Kern County found much lower levels of
chloropicrin (<30 - 750 ng/m3, 8-week averages ranging from <30 - 42
ng/m3), but chloropicrin was not being used extensively during the
season at that location (CARB 2004).  Most of the samples collected (185
of 198) were below the detection limit (<30 ng/m3). An assessment of
chloropicrin risks to residents in rural communities estimated a mean 24
hour concentration of 210 ng/m3 for residents during periods of
chloropicrin application to nearby agricultural areas (Lee et al. 2002).
Ambient chloropicrin concentrations are presented in Table 6.

	

Table 6. Ambient air concentrations of chloropicrin near fumigated
fields.

Concentration

     (ng/m3)	Exposure Type	Location	Date	Reference

   210 ± 590

  <85 - 4600	

Rural residential	

Kern Co., CA	

1996	

Lee et al. 2002

     <85	

Urban residential	

Kern Co., CA	

1996	

Lee et al. 2002

<30 -14,000 daily, 

8 week average = 

406 - 2270	

Rural residential	

Monterey, Santa Cruz Co., CA	

2001	

CARB 2004

<30 - 3,300 daily, 

8 week average = 660	

Urban residential	

Monterey, Santa Cruz Co., CA	

2001	

CARB 2004

<30 - 750, 8 week average = <40	Rural residential	Kern Co., CA	2001	CARB
2003

	3.  Measures of Aquatic Exposure  TC "3.  Measures of Aquatic Exposure"
\f C \l "3"  

a.  Aquatic Exposure Modeling  TC "a.  Aquatic Exposure Modeling" \f C
\l "4"    HYPERLINK \l Generated Bookmark38  

	Henry’s Law constant (2.05-3 atm-m3/mol) of chloropicrin suggest that
rapid volatilization of chloropicrin from water and soil surfaces is
expected to be an important process. Since Tier I model GENEEC is not
capable in accounting the loss of the vapor phase of chloropicrin from
the fumigated field, Tier II PRZM/EXAMS was used in estimating
chloropicrin concentrations in surface water. Additional chemical
specific physical parameters vapor phase diffusion coefficient (DAIR)
and enthalpy of vaporization (ENPY) were activated during the PRZM/EXAMS
simulation. Intended application methods via shank or drip irrigation
are to fumigate subsurface uniformly.  Therefore, chemical application
method (CAM) of 8 was used in mimicking subsurface fumigation of
chloropicrin to simulate its uniform distribution within 25 cm through
vapor diffusion under the tarp. Six field scenarios - California
tomatoes, California onion, Florida strawberries, Florida tomato, North
Carolina tobacco and North Carolina sweet potato were used in estimating
EECs using highest application rate of 350 lbs/Acre. Chloropicrin uses
in major crops like tomato, strawberries and tobacco as well as minor
crops like onion and sweet potato scenarios were used in simulating
PRZM/EXAMS to capture aquatic exposure under diverse crop scenarios.

	PRZM (v3.12.2, May 2005) and EXAMS (v2.98.4.6, April 2005) are
screening simulation models coupled with the input shell pe5.pl (Aug
2007) to generate daily exposures and 1-in-10 year EECs of oryzalin that
may occur in surface water bodies adjacent to application sites
receiving chloropicrin through runoff. A Mississippi pond scenario was
used to determine estimated environmental concentrations (EEC) for
ecological risk assessment. Each described a generic scenario for the
EXAMS portion of the modeling exercise.  Important input parameters used
for the PRZM/EXAMS modeling are shown in Table 7.

Table 7.  PRZM/EXAM  Input Parameters for Chloropicrin

Parameters	Values & Units	Sources

Molecular Weight	164.39 g Mole-1	MRID 43613901

Vapor Pressure 25oC	23.8 mm Hg	Merck Index

Water Solubility @ pH 7.0 and 25oC	1621 mg L-1	MRID 43613901

DAIR	4858.6 cm2/day	Fuller et al., 1966

ENPY	9.39 kcal/mole 

(39.3 kj/mol)	Chickos and Acree, 2003

Henry’s Law Constant @ 25oC	2.05 X 10-3 atm M3/mole 	Kawamoto and
Urano, 1989

Hydrolysis Half-Life (pH 7)	Stable 	MRID 43022401

Aerobic Soil Metabolism t½,	5.33 days 	Calculated 90th Percentile

MRID#s 43613901

Wilhelm et al., 1996

Aerobic Aquatic metabolism:	10.33 Daysa	EFED Guideline

Anaerobic Aquatic metabolism: for entire sediment/water system	0.03 Days
X 3b	MRID 43759301

Aqueous Photolysis	1.3 Day	MRID#s 42900201

Soil Water Partition Coefficient	 36.05 L Kg-1 	EPISUITEc

Pesticide is Wetted-In	No	Product Label

Crop Management

Application rates (lb a.i./A) and Frequency	350 and 1X	Shank injectiond

Fumigation  Date for Florida and California 

Fumigation  Date for North Carolina 

	September 15

April 15	USDA

Application Method	Ground Application

(CAM 8) d	Standard assumption    

Application Efficiency	100%	Standard assumption     

a  In absence of aerobic aquatic metabolism half-life,  the reported
half-lives of aerobic soil metabolism multiplied by 2 according to
Guidance for selecting input parameters in modeling for environmental
fate and transport of pesticides. Version II. Februay 27, 2002.

b  For a single anaerobic aquatic metabolism value, multiplied by 3,
according to Guidance for selecting input parameters in modeling for
environmental fate and transport of  pesticides  Version II. February
27, 2002.

c  The EPI (Estimation Program Interface) Suite is a Windows® based
suite of physical/chemical property and environmental fate estimation
models   developed by the EPA’s Office of Pollution Prevention Toxics
and Syracuse Research Corporation SRC.
http://www.epa.gov/opptintr/exposure/docs/updates_episuite_v3.11.htm

d  Chemical Application method 8 using shank Injection to assume uniform
distribution of chloropicrin within upper 25 cm soil depth

	

There are is an uncertainty in estimating chloropicrin exposure in water
bodies due to post-application tarping of the treated area. If tarping
is used to minimize the volatilization of chloropicrin, the loading of
the chemical through runoff will be limited until the tarp is sliced or
removed from the field. The present version of PRZM model and selected
crop scenarios have limited capabilities in capturing the load of
applied chemical under a post-application tarp scenario. Therefore, the
estimated concentrations of chloropicrin in water bodies may be upper
bound for tarped scenarios since the load of chloropicrin from runoff is
considered in the
PRZM/E䅘卍猠浩汵瑡潩⹮ഉ名扡敬㠠›獅楴慭整⁤湅楶潲
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μg/L	Chronic

 21-day Avg. EEC

μg/L	Chronic 

60-day Avg. EEC

μg/L)

California Tomato	350 lbs a.i./Acre

 1X Per Season	0	0	0

California 

Onion	350 lbs a.i./A

1X Per Season	1.05	0.24	0.09

Florida 

Tomato	350 lbs a.i./Acre

1X Per Season	78.73	19.27	6.84

Florida Strawberry	350 lbs a.i./Acre

1X Per Season	63.11	12.77	4.51

North Carolina

Sweet Potato	350 lbs a.i./Acre

1X Per Season	0.85	0.25	0.09

North Carolina

Tobacco	350 lbs a.i./Acre

1X Per Season	0.78	0.24	0.09

a Based on 1-in-10 year exceedance probability (0.10).

	Results of the 1-in-10 year probabilities are summarized in Table 8 and
the full set of EECs are given in Appendix B.1.1 to B3.2. In addition,
the method for calculating a 1-in-10 year EEC is described in Appendix
B.  The EECs presented in Table 8 were used in this ecological risk
assessment.

	The important output parameters for the modeling exercises are the
peak, 21 day, and 60 day chloropicrin levels estimated in the model
pond. The highest EECs were observed for the Florida tomatoes and
Florida strawberries scenarios.  The large variation of chloropicrin
levels estimated in surface waters can be traced to chemical loadings
into the environmental pond from the PRZM output.  Since the chemical
input parameters are identical in each PRZM run, the different outputs
are entirely dependent upon the different soil parameters used in the
corresponding crop scenarios during the PRZM portion of the modeling
exercise, as well as the scenario-specific meteorological data.  A much
higher percentage of pesticide was leached below the root zone level for
the North Carolina and California scenarios as compared to the Florida
scenarios due to a number of factors such as slope, soil type, moisture
content, and the runoff curve numbers used for the different fields. 
This resulted in runoff and erosion flux vectors for the North Carolina
and California scenarios were considerably lower than those estimated
from the Florida tomatoes and Florida strawberries scenarios.  As a
consequence, the chloropicrin loadings into the EXAMS model environment
were much lower, resulting in the smaller EECs. 

			b.  Aquatic Exposure Monitoring and Field Data  TC "b.  Aquatic
Exposure Monitoring and Field Data" \f C \l "4"  

	Rapid volatilization of chloropicrin from water and soil surfaces is
expected to be an important route of dissipation from the environment. 
Photolytic degradation of chloropicrin in water is also an important
route of dissipation. Since this compound is very soluble in water and
has low adsorption into soil, it can potentially leach into shallow
ground water and leaky aquifers, as well as, may transport to nearby
surface water through runoff and erosion, especially if chloropicrin
application coincides with, or is followed soon by a rain event.
Chloropicrin has been detected in the non-targeted monitoring wells.
Based on the data base of pesticides in groundwater (U.S. EPA, 1992),
chloropicrin was found at less than 1.00 μg/L in three wells from
15,175 wells in Florida. 

	C.  Ecological Effects Characterization  TC "C.  Ecological Effects
Characterization" \f C \l "2"  	

	Effects characterization describes the potential effects a pesticide
can produce in an aquatic or terrestrial organism.  This
characterization is typically based on studies that describe acute and
chronic effects toxicity information for various aquatic and terrestrial
animals and plants.  However, data for chloropicrin, while relatively
extensive for mammals, are very limited otherwise.  Appendix C
summarizes the results of the toxicity studies used to characterize
effects for this risk assessment.  Toxicity testing reported in this
section does not represent all species of 

birds, mammals, or aquatic organisms.  Only a few surrogate species for
both freshwater fish and birds are used to represent all freshwater fish
(2000+) and bird (680+) species in the United States.  For mammals,
acute studies are usually limited to Norway rat or the house mouse.

Estuarine/marine testing is usually limited to a crustacean, a mollusk,
and a fish.  Also, neither reptiles nor amphibians are tested.  The risk
assessment assumes that avian and reptilian toxicities are similar.  The
same assumption is used for fish and amphibians.

	In general, categories of acute toxicity ranging from “practically
nontoxic” to “very highly toxic” have been established for aquatic
organisms (based on LC50 values), terrestrial organisms (based on LD50
values), avian species (based on LC50 values), and non-target insects
(based on LD50 values for honey bees) (EPA 2001).These categories are
presented in Appendix C.

		1.  Aquatic Effects Characterization  TC "1.  Aquatic Effects
Characterization" \f C \l "3"  

			a.  Aquatic Animals

	The most sensitive acute toxicity references values associated with
chloropicrin exposure to aquatic organisms are summarized in Table 9.  
No chronic data are available.  A more detailed summary of the available
aquatic toxicity data is given in Appendix C.

Table 9.  Chloropicrin toxicity reference values (TRVs) (ppb of active
ingredient) for aquatic organisms

Exposure Scenario	

Species 	Exposure Duration	Toxicity Reference Value (ppb a.i.)	

Reference

Freshwater Fish

Acute	Rainbow trout	96 hours	LC50 = 5.14 ppb

(very highly toxic)	MRID 471021-02

Supplemental Study

Chronic	NA	NA	NA	NA

Freshwater Invertebrates

Acute	Daphnia pulex 	48 hours	LC50 <71 ppb 

(very highly toxic)	MRID 130704

Supplemental Study

Chronic	NA	NA	NA	NA

Estuarine/Marine Fish

Acute	NA	         NA	NA	NA

Chronic

	NA	NA	NA	NA

Estuarine/Marine Invertebrates

          Acute	          NA	        NA	NA	NA

Chronic	NA	NA	NA	NA

Aquatic Plants

Acute	NA	NA	NA	NA

NA = Data appropriate for quantitative use are not available.

		Acute Toxicity to Freshwater Fish  TC "Acute Toxicity to Freshwater
Fish" \f A \l "5"  

	The acute toxicity of chloropicrin to freshwater fish was evaluated in
rainbow trout and bluegill sunfish, with lowest LC50s of  5.14 ppb (very
highly toxic) and 44.1 ppb (very highly toxic), respectively.  The
rainbow trout value is used as the toxicity value for assessing acute
risks to fish from exposure to chloropicrin.

	

	Acute Toxicity to Freshwater Invertebrates  TC "Acute Toxicity to
Freshwater Invertebrates" \f A \l "5"  

	

	The acute toxicity of chloropicrin to aquatic invertebrates has been
assessed in Daphnia pulex, with a 48-hour LC50 value of < 71 ppb (very
highly toxic). The value is expressed as “less than” the numeric
value, since chloropicrin is highly volatile and measured residues were
below the Level of Quantitation at the lowest four test levels at 48
hours.  Although residues were below the Level of Quantitiation, 10 -
20% mortality of daphnids occurred at these test levels.

	

		2.  Terrestrial Effects Characterization  TC "2.  Terrestrial Effects
Characterization" \f C \l "3"  

			a.  Terrestrial Animals

	The toxicity endpoints used to characterize risks of chloropicrin
exposure to birds and mammals are summarized in Table 10.  Results of
all studies in terrestrial animal species are summarized in Appendix C.

Table 10.  Toxicity reference values (TRVs) for terrestrial species for
chloropicrin

Exposure Scenario	Species	Exposure Duration	Toxicity 

Reference Value1	Reference

Mammals

Acute oral	Rat	Single oral dose	LD50 = 37.5 mg/kg

(highly toxic)	MRID 05014376

Acceptable/Guide-line

Acute inhalation	Rat	4-hour inhalation	LC50 = 17 ppm (M)  and 19 ppm (F)

[conv. to mg/L: Section IV.B.2]	MRID 45117902

Acceptable/Non-guideline

Chronic inhalation 	Rabbit	6 hrs./day on days 7 - 29 (inhalation)       
 	NOAEL = 0.4 ppm (0.003 mg/L)	MRID 42740601

Acceptable/ guideline

Birds

Acute	No Data

Chronic	No Data	

1Data from 9/30/04 and 1/31/05 HED Chloropicrin Assessments.

Mammalian Species

	

Based on the above results of an acute oral toxicity study in rats, EFED
considers chloropicrin to be highly toxic to mammals.  The acute oral
value is used in this risk assessment only for the LD50 per square foot
preliminary analysis.  The acute inhalation and chronic inhalation
endpoints are used for the inhalation analyses.  

IV.  Risk Characterization  TC "IV.  Risk Characterization" \f C \l "1"
 

	A.  Risk Estimation - Integration of Exposure and Effects Data  TC "A. 
Risk Estimation - Integration of Exposure and Effects Data" \f C \l "2" 

	

			1.  Non-target Aquatic Animals and Plants  TC "1.  Non-target Aquatic
Animals and Plants" \f C \l "3"  

	There are uncertainties in estimating chloropicrin exposure in surface
water from post-application, due to tarping of the treated area.  If
tarping is used to minimize the volatilization of chloropicrin, the
loading of the chemical through runoff will be limited until the tarp is
sliced or removed from the field. The present version of the PRZM model,
as well as the selected crop scenarios, has limited capabilities in
discounting the load from runoff of applied chemical under a
post-application tarp scenario. Since the load of chloropicrin from
runoff is considered in the PRZM/EXAMS simulation, the estimated
concentrations of chloropicrin in surface water bodies may be upper
bound. Therefore, PRZM/EXAMS estimated exposure values may contribute
upper bound LOCs for the aquatic organisms under tarped scenarios. Since
the application rate has a linear relationship with EECs under identical
PRZM/EXAMS simulation for crop scenario, the calculated EECs for
untarped scenarios would be half of the tarped scenarios, based on a 175
lbs/A application rate for untarped scenarios (Table 11). A sample
output of FL Strawberry for untarped scenario confirmed the above
assumption and can be found in Appendix C.

	Risk quotients for aquatic animals are presented in Table 11.  The risk
quotients are calculated using the toxicity values summarized in Table 9
and EECs from PRZM/EXAMS summarized in Table 8.  For assessing acute
risks, the 24-hour peak concentration is used.  Chronic toxicity data
are not available to calculated chronic risk quotients. 

Table 11.  Risk Quotients (RQs) for chloropicrin for acute exposures of
aquatic species.

Exposure Scenario	Exposure (ppb)	Toxicity Reference Value (ppb)	Risk
Quotient1

Freshwater Fish

Acute risk2

California tomato	0	5.14 	--

California onion	1.05 (T)a

0.53 (UT)b	5.14	0.20**

0.10**

Florida tomato	78.73 (T)

39.37 (UT)	5.14	15.32***

7.66***

Florida strawberry	63.11(T)

31.56 (UT)	5.14	12.28***

6.14***

North Carolina sweet potato	0.85 (T)

0.43 (UT)	5.14	0.17**

0.08*

North Carolina tobacco	0.78 (T)

0.39 (UT)	5.14 	0.15**

0.08*

Freshwater Aquatic Invertebrates

Acute risk4

California tomato	0	<71	--

California onion	1.05 (T)

0.53 (UT)	<71	>0.01

>0.01

Florida tomato	78.73 (T)

39.37 (UT)	<71	>1.11***

>0.55***

Florida strawberry	63.11(T)

31.56 (UT)	<71	>0.89***

>0.44**

North Carolina sweet potato	0.85 (T)

0.43 (UT)	<71	>0.01

>0.01

North Carolina tobacco	0.78 (T)

0.39 (UT)	<71	>0.01

>0.01

a Tarped 

b Untarped 

*Exceeds acute endangered species LOC (> 0.05)

**Exceeds acute endangered species LOC and acute restricted use LOC (>
0.1)

***Exceeds acute endangered species LOC, acute restricted use LOC, and
acute risk LOC (> 0.5)

Freshwater Fish 

	The table has been revised, based on aquatic toxicity data received by
EFED since the last revised assessment (4/5/07), as well as new EECs.  A
rainbow trout endpoint of 5.14 ppb is used instead of the previous value
of < 16.98 ppb.  As shown by the asterisks in the table above, five of
six scenarios exceed LOCs.  Specifically, maximum risk quotients (i.e.,
at tarped rates) exceed a) the endangered species acute LOC (0.05) and
the restricted use LOC (0.1) for the five scenarios and  b) the acute
risk LOC (0.5) for Florida tomatoes and strawberries.  

Freshwater Invertebrates

The table was revised for aquatic invertebrates due to new EECs.  A new
endpoint (170 ppb) based on data received since the last assessment is
higher (i.e., less toxic) than the value used above (< 71 ppb), and is
thus not used for this screen.  For aquatic invertebrates, maximum risk
quotients (i.e., at tarped rates) exceed the endangered species acute
LOC (0.05), the restricted use LOC (0.1) and the acute risk LOC (0.5)
for at least Florida tomatoes and strawberries.  Given that all risk
quotients above zero are expressed as “greater than” their numeric
values, additional scenarios could potentially exceed LOCs.  Some
mortality occurred in the aquatic invertebrate study even at test levels
where residues were below the Level of Quantitation at 48 hours.    

		2.  Non-target Terrestrial Animals  TC "2.  Non-target Terrestrial
Animals" \f C \l "3"  

	

			a. Risk to Mammals

	EFED has used the established LD50/square foot risk assessment method
for mammals as a risk calculation screen.  This method is considered to
cover all routes of exposure, although it uses an acute oral toxicity
value.  It is typically used for granular and similar products, but it
is considered acceptable for use as a screen for chloropicrin. 
Uncertainties of the method, in 

general, include 1) non-oral routes of exposure may be either more or
less hazardous than the 

oral route, and 2) an organism would not typically take up all the
toxicant from any given square foot, and the amount of toxicant in this
unit of area may be more or less than that which an organism receives
overall as a dose.  For evaluating exposure to a highly volatile
chemical applied below ground, there is added uncertainty since all the
chemical applied is not available at the surface at any one time, for
example.  It’s value for the present assessment is as a preliminary
screen to confirm whether a refined route-specific (e.g., inhalation)
analysis is appropriate.  That is, the LD50/square foot calculations
reflect all routes of exposure.  One then looks more closely at the
individual routes of exposure that are most appropriate (i.e.,
inhalation for fumigants) (E. Odenkirchen, personal communication).

	At 350 lb ai/A of chloropicrin, there would be 3,645 mg ai/square foot
(given 43,560 square feet/A and 453,590 mg/lb).  This exposure amount is
divided by the product of acute oral LD50 for mammals (37.5 mg/kg) and
body weight of mammal (in kg) to calculate risk quotients. Three mammal
body weights are assessed: 15 g, 35 g, and 1000 g.  The resulting risk
quotients (LD50s/sq. ft.) for these three sizes of mammals are 6,480;
2,777; and 97, respectively.  These far exceed the acute risk LOC of
0.5, as well as the acute restricted use LOC of 0.2 and the acute
endangered species LOC of 0.1.  Thus, this preliminary screen indicates
a potential for concern for risk to wild mammals, and a need for further
analysis.  

	The main route of wild mammal exposure is likely to be from inhalation
of chloropicrin off-gassing from treated fields.  Mammalian inhalation
toxicity data are available.  However, EFED does not currently have
established LOCs based on inhalation exposure.  Nevertheless, an
inhalation risk concern for wild mammals has been identified.  See the
Risk Description for the more refined assessment of risk based on
inhalation exposure. 

 			b. Risk to Avian Species

	The main route of exposure of birds is likely to be from inhalation of
chloropicrin off-gassing from treated fields.  However, avian inhalation
data are not available.  EFED has used the established LD50/square foot
method for mammals as a rough risk calculation screen (see above). 
However, this screen has not been done for birds since the necessary
acute oral value for birds with chloropicrin is not available.  See the
Risk Description for analysis of inhalation risk to mammals and how this
relates to potential risk to birds.

		3.  Non-target Terrestrial and Semi-aquatic Plants  TC "3.  Non-target
Terrestrial and Semi-aquatic Plants" \f C \l "3"  

	Plant toxicity data [123-1(a), 123-1(b)] are needed for risk assessment
because of the potential for exposure and risk to exposed terrestrial
and semi-aquatic plants off-site.

	B.  Risk Description  TC "B.  Risk Description" \f C \l "2"  

		1.  Risk to Aquatic Organisms  TC "1.  Risk to Aquatic Organisms" \f C
\l "3"  

			A.  Animals

Chloropicrin has the potential to reach surface water bodies.  EECs to
determine the acute and chronic risk to aquatic organisms were estimated
using PRZM/EXAMS models with selected scenarios (CA tomatoes, CA onions,
FL tomatoes, FL strawberries, NC sweet potatoes, NC tobacco), to
represent the numerous crops for which chloropicrin is registered for
use.  Although the same application rate of 350 lbs ai/A was used for
all scenarios, the chloropicrin exposure estimated resulted in different
risk potentials, due to the different conditions (e.g., rainfall, soil
temperature) for each modeled location.  Also, for a given amount of
chloropicrin transported to a water body, there is expected to be
greater aquatic organism exposure in colder waters, since the Henry’s
Law Constant will be lower in colder waters, resulting in lower
volatilization (and conversely, lower exposure in warmer waters).   

  Based on this exposure assessment:  for fish, maximum risk quotients
exceed a) the endangered species acute LOC (0.05) and the restricted use
LOC (0.1) for five of six scenarios and  b) the acute risk LOC (0.5) for
Florida tomatoes and strawberries.  For aquatic invertebrates, maximum
risk quotients exceed all three of the above LOCs for at least Florida
tomatoes and strawberries. Given that aquatic invertebrate risk
quotients above zero are expressed as “greater than” their numeric
values, additional scenarios could potentially exceed LOCs.  Also, only
a select number of use sites have been modeled, and it is likely that
other use sites would have aquatic exposures in the range of those sites
modeled.  However, there are also substantial uncertainties concerning
exposure modeling values, as described earlier.

In addition to the toxicity values used for risk quotients, a literature
search value for the mysid shrimp (257.8 ppb) was located via ECOTOX
(Carr, 1987).  However, this reported value was based on a static test
without measured concentrations, unlike the submitted and reviewed
daphnid study where some measured concentrations were available.  Also,
the reported mysid value is higher (i.e., implying lower toxicity) than
that available daphnid study (although with no confirmation of residues
at all in the mysid study, it is not possible to confirm what the
toxicity is).  It is thus not used quantitatively in this screening
assessment. 

			B.  Plants

	Aquatic plant toxicity data (123-2) are needed for risk assessment
because of the potential for exposure and risk to aquatic plants
off-site.

		2.  Risk to Terrestrial Organisms  TC "2.  Risk to Terrestrial
Organisms" \f C \l "3"  

			A.  Animals

	EFED’s major concern with chloropicrin in the terrestrial environment
is that it is highly volatile and can off-gas from treated fields and
potentially expose a range of nontarget terrestrial organisms in its
path.  Given the broad spectrum use of chloropicrin, it is assumed that
most living organisms in the treated fields (including any beneficial
insects and/or burrowing mammals) would be at high risk of mortality. 

	EFED used the screening-level LD50/ft2 method as a preliminary step to
assess risks of the pesticide to mammals.  This method has most
frequently been applied to pesticide application scenarios involving
granular formulations, seed treatments, and baits.  The method has not
been generally applied to situations involving highly volatile
compounds, but remains the Agency’s most appropriate index for this
type of use.  This LD50/ft2 method is an index that does not
systematically account for exposures from each potential route, but
considers the overall potential for adverse effects given a bioavailable
amount of pesticide conservatively related to the mass applied per unit
area at the treatment site.  See the uncertainty discussion in the Risk
Estimation section above.  Three mammal body weights are assessed: 15g,
35g, and 1000g.  The resulting risk quotients for these three sizes of
mammals are 6,480, 2,777, and 97, respectively (see the Risk Estimation
section above).  These far exceed the acute risk LOC of 0.5, as well as
the acute restricted use LOC of 0.2 and the acute endangered species LOC
of 0.1.  Thus, this preliminary screen indicates a potential for concern
for risk to wild mammals, and a refined analysis based specifically on
inhalation exposure is described below. 

	Owing to the limitations of the the LD50/ft2 method for highly volatile
compounds and the recognized high potential volatility of chloropicrin,
EFED investigated the potential for inhalation to be a toxicologically
significant route of exposure to birds and mammals within the use area. 
While data on inhalation toxicity are available for mammals (from HED),
inhalation toxicity data are not available for birds.

	Available ambient monitoring data for chloropicrin indicates a maximum
ambient air residue of 14,000 ng/m3 (see Table 6).  This is equivalent
to a chloropicrin air concentration of 0.000014 mg/L.  A comparison of
this air concentration with available mammalian acute inhalation effects
data (LC50 of 0.114 mg/L) would indicate a risk quotient of 0.00012,
well below any LOC.

	Monitoring data for a limited number of application sites is not
necessarily predictive of all site conditions where the pesticide may be
used.  Also, most monitoring data is for samples collected at least 1.0
m above the ground, often higher.  This height is above the level for
many ground-dwelling mammals and ground-feeding birds.  It is reasonable
to assume a gradient of concentrations at the treatment site, with
higher concentrations of chloropicrin occurring closer to the ground. 
This would be especially applicable to those times that a tarp is not
used (and animals would be more likely to be on the soil surface of the
treated field).  Thus, modeling has been used to attempt to estimate
residues closer to the field and ground.  

	The ISCST3 model provides more flexibility compared to the monitoring
data (i.e., results are more easily extrapolated) and generally allows
the Agency to consider a much broader set of circumstances in its
assessments.  Nevertheless, since EFED is relying on monitoring data
from outside of the treated field, the model calculation does not
specifically produce on-field, ground surface level air residues. 
Because of uncertainties associated with both monitoring and modeling,
the Agency has calculated risk estimates based on both, for comparison.

	The ISCST3 model estimated concentrations were used in calculating the
concentrations on the edge of the field from a field application of
chloropicrin.  The highest air concentration of 0.019 mg/L was
estimated.   With an acute mammal inhalation LC50 of 17 ppm (0.114
mg/L), the risk quotient for this modeled concentration is 0.17 (0.019
/0.114).

	The Agency has not established level of concern (LOC) thresholds
expressly for the interpretation of RQs calculated for inhalation
exposure risks.  However, if the existing LOC values for acute mammalian
wildlife risk were used to evaluated such RQs, the above analysis based
on modeling (risk quotient of 0.17) would suggest that at least some
uses of chloropicrin could exceed the acute endangered species LOC
(0.1), but not the acute restricted use LOC (0.2) or acute risk LOC
(0.5).  The uncertainty level in these analyses can be reduced with
submission of ground-level monitoring data (e.g., 3 inches) both
within-field and edge-of-field, for maximum application rates.

The Probabilistic Exposure and Risk model for Fumigants (PERFUM) has
been used by EFED since the last chloropicrin reregistration risk
assessment (4/5/07) to refine the potential risks to terrestrial
organisms from chloropicrin uses.  PERFUM was developed to address the
issue of bystander exposures to fumigants following agricultural
applications. PERFUM incorporates actual weather data and flux
distributions estimates and accounts for changes relative to the time of
day and altering conditions.  It is also capable of providing
distributional outputs for varying receptor locations and using varied
statistical approaches. Appendix F provides PERFUM model information and
results.   Twelve different application scenarios (e.g., broadcast,
bedded, tarped, untarped, drip irrigation, Bakersfield/Ventura sites,
application rates up to 350 lb ai/A) were modeled.  The highest 90th
percentile air residue across these scenarios is 4,219 μg/ m3, for 40
acres, broadcast, untarped, 0 – 5 meters radius from the field edge, 8
– 12 hours after application at 175 lb ai/A.  The risk quotient for
terrestrial vertebrates (using mammal data) for this modeled
concentration is 0.037 (0.004219 mg/L / 0.114 mg/L), below the 0.1
endangered species LOC.  See Section 5 for probabilities of individual
effect at the 0.1 equivalent LOC.

	The above assessment is limited to acute effects and exposure windows. 
Wild mammals may have home ranges in the treatment area and may be
exposed continuously and/or repeatedly as the result of chloropicrin use
on multiple fields over multiple days in any geographic area.   Given
that the rabbit inhalation developmental toxicity NOAEL for chloropicrin
is 0.003 mg/L (with the developmental LOAEL of 0.008 mg/L based on
abortions and decreased fetal weights), lower than the acute inhalation
endpoint, EFED investigated the potential for a concern for chronic
exposure and effects.   Given the short atmospheric half-life of
chloropicrin described earlier, it appears unlikely than long-term
exposure would occur from any single application of chloropicrin. 
However, multiple fields may be treated in an area over a number of
days.  Therefore, there still exists a potential that mammals within an
area of multiple treated fields may be exposed to chloropicrin emissions
on a repeated basis over time.  Comparison of the previously cited
maximum ambient air residues (0.000014 mg/L) to the 0.003 mg/L NOAEL
above implies that ambient air residues are likely to be well below
developmental effect levels.

	The above analysis is based on mammalian toxicity data for the
inhalation route.  A similar analysis could be performed for birds, if
the necessary data were available.  However, no inhalation toxicity data
for chloropicrin are available for birds.  If acute toxicity by the oral
route were available for both mammals and birds, an evaluation of the
relative sensitivity via the oral route might be extrapolated to the
inhalation route to estimate an acute inhalation endpoint for birds. 
However, no acute oral LD50 data for chloropicrin are available for
birds.  Therefore, EFED is limited to an assumption of equivalent
sensitivity between birds and mammals for  exposure through inhalation. 
EFED feels that such an extrapolation may not be protective, given
higher respiration rates for birds versus mammals, and physiological
differences in the avian lung that would tend to favor higher diffusion
rates across the lung membrane when compared to mammals.  Therefore,
inhalation analyses that suggest a potential for adverse effects in
mammals would also suggest potential risks to birds via the inhalation
route, but analyses not indicating risk to wild mammals would not
necessarily be true for birds also.  

	Although birds are mobile and some may only have a very brief exposure
flying by, others may have territories or nests in the area and be
exposed more substantially and/or repeatedly (in addition, eggs are gas
permeable and could be exposed).  Repeat exposures can occur since
chloropicrin may be applied to different fields in a given geographic
area on different days.  The uncertainty level can be reduced with this
screening-level analysis by submission of avian acute inhalation
toxicity data, in addition to the above-cited ground-level monitoring
data.  A laboratory subchronic/chronic avian inhalation study will help
EFED address potential repeated exposure of birds over time in the wild.

	There is also a concern for sublethal effects from chloropicrin.  For
example, if chloropicrin caused terrestrial wildlife to flee a nesting
area, reproduction could be adversely affected. 

			B.  Plants

	Based on the phytotoxicity of chloropicrin on the treated fields, it is
expected that non-target plants off-site may also be a risk from
off-gassed chloropicrin.  Terrestrial plant guideline toxicity data are
needed to evaluate this risk. 

		3.  Review of Incident Data  TC "3.  Review of Incident Data" \f C \l
"3"  

	

	Limited terrestrial animal (non-human) incident data are available for
chloropicrin.  For example, there was an incident in Europe, in which a
mis-labeled product that was later determined to contain chloropicrin
was inadvertently used in a greenhouse in combination with metam sodium.
 It resulted in large numbers of domestic animal deaths when the
chloropicrin gas escaped to the surrounding area (Selala, et. al. 
1989).  Although this incident does not reflect the expected exposure
from labeled uses reviewed in the present risk assessment, it does
indicate the potential for hazard if chloropicrin were to be mis-handled
and get into the ground-level air at high concentrations.

	In an aquatic animal incident involving chloropicrin and telone
beginning 9/1/05, several thousand dead fish were reported over a 3-mile
reach of Casserly Creek in Santa Cruz County, California.  The mortality
appeared to begin near a strawberry field being fumigated (using
chemigation) with the product Inline (R).  Species killed included
steelhead/rainbow trout, sculpin, hitch, and Sacramento blackfish. 
Crayfish were also killed (I-016955-001; 11/18/05 Pesticide Laboratory
Report, California Department of Fish and Game). Inline (R)
(Registration number 62719-348) is a 60.8 % telone/33.3 % chloropicrin
product.  EFED has assigned a certainty level in the Ecological Incident
Information System (EIIS) of “highly probable” for chloropicrin in
this incident, based on the 11/18/05 report.  There is no mention of
rain in the 11/18/05 report, the applicator has cited a possible
defective valve in a flush line (I-016884), and the registrant has
claimed that a valve was mistakenly opened (I-016738-016). EFED has
categorized the incident as “Misuse (accidental)” in the EIIS. 

   

	Also, fish farm incidents have shown the potential for another
off-gassed fumigant, MITC (from agricultural application of
metam-sodium) to be inadvertently drawn into man-made aeration systems,
resulting in possible fish mortality.  Based on the similar off-gassing
potential of chloropicrin, this same risk may apply to this chemical, if
it is applied to fields in the vicinity of fish farms with air intake
systems.  Chloropicrin is heavier than air and could potentially travel
along the ground and be inadvertently drawn into such systems.	

Three plant incidents involving fumigant products with chloropicrin as
one of the active ingredients have been identified in a 1/19/06 report
by M. Kathleen O’Malley (ITRMD/OPP).  One of these involved the
product Telone C-35 (62719-302; 63.4% telone, 34.7% chloropicrin) and
was coded as major by ITRMD.  The other two incidents were coded by
ITRMD as minor: one involved this same combination product with telone;
the other involved a combination product with methyl bromide (Tri-con
57/43 Preplant Soil Fumigant; 11220-4, 57% methyl bromide, 42.6%
chloropicrin).  The major incident (I 014702-076) is in EIIS, and
involved 91 acres of watermelon. EIIS also lists an additional plant
incident involving reported damage to an apple orchard in 1998 (I
007358-001).  These incidents help confirm the EFED assumption that
chloropicrin has the potential to adversely affect non-target plants.  

		4.  Endocrine Disruption  TC "4.  Endocrine Disruption" \f C \l "3"  

	Chloropicrin does not appear to present a specific endocrine disruption
risk at present.  Nevertheless, EPA is required under the FFDCA, as
amended by FQPA, to develop a screening program to determine whether
certain substances (including all pesticide active and other
ingredients) "may have an effect in humans that is similar to an effect
produced by a naturally occurring estrogen, or other such endocrine
effects as the Administrator may designate."  Following the
recommendations of its Endocrine Disruptor Screening and Testing
Advisory 

Committee (EDSTAC), EPA determined that there was a scientific basis for
including, as part of the program, the androgen and thyroid hormone
systems, in addition to the estrogen hormone

system.  EPA also adopted EDSTAC’s recommendation that the Program
include evaluations of potential effects in wildlife.  For pesticide
chemicals, EPA will use FIFRA authority, and, to the

extent that effects in wildlife may help determine whether a substance
may have an effect in humans, FFDCA  authority, to require the wildlife
evaluations.  As the science develops and resources allow, screening of
additional hormone systems may be added to the Endocrine Disruptor
Screening Program (EDSP).  When the appropriate screening and/or testing
protocols being considered under the Agency’s EDSP have been
developed, chloropicrin may be subjected to additional screening and/or
testing to better characterize effects related to endocrine disruption.

	5.  Federally Threatened and Endangered (Listed) Species Concerns  TC
"5.  Federally Threatened and Endangered (Listed) Species Concerns" \f C
\l "3"   

		A.  Action Area

  TC "A.  Action Area" \f C \l "4"  

	For listed species assessment purposes, the action area is considered
to be the area affected directly or indirectly by the Federal action and
not merely the immediate area involved in the action.  At the initial
Level I screening assessment, broadly described taxonomic groups are
considered and thus conservatively assumes that listed species within
those broad groups are co-located with the pesticide treatment area. 
This means that terrestrial plants and wildlife are assumed to be
located on or adjacent to the treated site, and aquatic organisms are
assumed to be located in a surface water body adjacent to the treated
site.  The assessment also assumes that the listed species are located
within an assumed area which has the relatively highest potential
exposure to the pesticide, and that exposures are likely to decrease
with distance from the treatment area.  Section II. B of this risk
assessment presents the pesticide use sites that are used to establish
initial collocation of species with treatment areas.  

	If the assumptions associated with the screening-level action area
result in RQs that are below the listed species LOCs, a "no effect"
determination conclusion may be made with respect to listed species in
that taxa, and no further description of an action area is necessary. 
Furthermore, RQs below the listed species LOCs for a given taxonomic
group indicate no concern for indirect effects upon listed species that
depend upon the taxonomic group covered by the RQ as a resource.  

	However, in situations where the screening assumptions lead to RQs in
excess of the listed species LOCs for a given taxonomic group, a
potential for a "may affect" conclusion exists and may be associated
with direct effects on listed species belonging to that taxonomic group
or may extend to indirect effects upon listed species that depend upon
that taxonomic group as a resource.  In such cases, additional
information on the biology of listed species, the locations of these
species, fate and transport properties of the chemical, and the
locations of use sites could be considered to determine the extent to
which screening assumptions regarding an action area apply to a
particular listed organism.  These subsequent refinement steps could
consider how this information would impact the action area for a
particular listed organism and may potentially include areas of exposure
that are downwind and downstream of the pesticide use site.

			B. Taxonomic Groups Potentially at Risk  TC "B. Taxonomic Groups
Potentially at Risk" \f C \l "4"  

	The Level I screening assessment process for listed species uses the
generic taxonomic group-based process to make inferences on direct
effect concerns for listed species.  The first iteration of reporting
the results of the Level I screen is a listing of pesticide use sites
and taxonomic groups for which RQ calculations reveal values that meet
or exceed the listed species LOCs.  In the majority of cases, the
screening-level risk assessment process reports RQ calculations for the
following broad taxonomic groupings:

	

Birds (also used as surrogate for terrestrial-phase amphibians and
reptiles)

Mammals

Freshwater fish (also used as a surrogate for aquatic phase amphibians)

Freshwater invertebrates

Estuarine/marine fish 

Estuarine/marine invertebrates

Terrestrial plants

Algae and aquatic plants

	For chloropicrin, risk quotients could not be calculated for most of
these, due to a lack of data.  There may also be taxonomic groups of
listed species for which screening tools are not fully developed nor
represented through surrogacy with existing tools.  For example, there
is no RQ calculation process for terrestrial invertebrates.  Since
chloropicrin is used to kill certain terrestrial invertebrates, it must
be assumed for a screening analysis that listed terrestrial
invertebrates may be directly adversely affected as well. 

				1.  Discussion of Risk Quotients

  TC "1.  Discussion of Risk Quotients" \f C \l "5"  

	Endangered Species LOCs are exceeded for wild mammals (equivalent LOC,
based on inhalation with one of two models used), fish, and aquatic
invertebrates based on acute risk quotients.  Although guideline avian
toxicity data are not available, birds may be as sensitive as mammals. 
Most aquatic invertebrate risk quotients are indeterminate (>) since the
toxicity values are indeterminate (<).  Thus, while some modeled site
risk quotients are clearly above endangered species LOCs (i.e., they are
above the LOC even without the >), additional scenarios could
potentially also exceed one or more LOCs.  Terrestrial invertebrates are
target species and thus nontarget terrestrial invertebrates may also be
at risk.  Plants on treatment sites may be susceptible to chloropicrin
and thus plants off-site may also be susceptible to off-gassed
chloropicrin.  Should estimated exposure levels resulting in RQs at or
above the endangered species LOC occur in proximity to listed resources,
the available screening level information suggests a potential concern
for direct acute effects on listed wild mammals, birds, fish, aquatic
invertebrates, terrestrial invertebrates, and plants associated with
soil fumigant sites. 

				2.  Probit Dose Response Relationship  TC "2.  Probit Dose Response
Relationship" \f C \l "5"  

	An analysis has been conducted of the probability of individual
mortality at an LOC of 0.1, the acute endangered species LOC for wild
mammals.  It is recognized that extrapolation of very low probability
events is associated with considerable uncertainty in the resulting
estimates. The analysis uses the EFED spreadsheet IECv1.1.xls, developed
by EFED (USEPA, 2004). 

	For mammals, slope and and confidence interval information for the
slope were not reported in the Data Evaluation Record for MRID 45117902,
an acute inhalation study.  Risk quotients in the ecological risk
assessment used the inhalation toxicity value for male rats, where there
was only one partial mortality.  Since probit results are not possible
with only one partial mortality, a default slope of 4.5 and confidence
interval of 2 to 9 are used for the individual mortality probability
analysis.  Based on an assumption of a probit dose response relationship
with a mean estimated slope of 4.5, the corresponding estimated chance
of individual mortality associated with the listed species LOC of 0.1,
the acute toxic endpoint for wild mammals, is approximately one in
294,000.  To explore possible bounds to such estimates, the upper and
lower values for the mean slope estimate (2 - 9) were used to calculate
upper and lower estimates of the effects probability associated with the
listed species LOC.  These values are approximately one in 44 and one in
1016 (default limit of Excel reporting).

	As previously indicated, the acute risk quotient for mammals is
estimated to be 0.17, based on ISCST3 modeling.  This is slightly higher
than the mammal acute endangered species LOC of 0.1.  Thus, the
probability of individual mortality at the predicted exposures used for
the risk quotients would also be higher than at the LOC.  Based on
PERFUM modeling, the acute RQ is estimated to be 0.037, below the LOC.
Thus, the probability of individual mortality at the predicted exposures
used for the risk quotients with this model would be lower than at the
LOC.  

	

	Data are not adequate to calculate individual effect probabilities for
freshwater fish and aquatic invertebrates.  This is due to a lack of
probit slope in the rainbow trout study used for risk assessment and
uncertainties in the measured concentrations in the daphnid study (in
the lowest four concentrations at 48 hours).  Data are not available to
calculate individual effects for other taxonomic groups.

	

		C.  Data Related to Under-represented Taxa  TC "C.  Data Related to
Under-represented Taxa" \f C \l "4"  

	Although the Level I screening assessment process relies on RQ
calculations that use toxicity endpoints selected from the most
sensitive species tested within broad taxonomic groups, there may be
situations in which additional effects data from one or more sources may
suggest that a given suite of listed taxa may be more or less sensitive
than suggested by the effects data used for RQ calculations.  In these
circumstances, the screening level RQs are not changed, but effects data
more specific to listed species may be used to evaluate the extent to
which screening-level RQs adequately represent conclusions regarding
effects on specific listed taxa.   However, this does not appear to
apply to chloropicrin.

		D.  Implications of Sublethal Effects  TC "D.  Implications of
Sublethal Effects" \f C \l "4"  

	 For mammals, adverse effects were seen in a variety of chronic
inhalation studies.  The endpoint selected for ecological risk
assessment is the developmental NOAEC of 0.4 ppm in rabbits.  Abortions
and decreased fetal weights occurred at the LOAEL of 0.8 ppm in this
study.

Thus, it is expected that sublethal effects could be seen in listed
mammals, if exposed at levels comparable to those producing effects in
the lab.

		E.  Indirect Effects Analysis  TC "E.  Indirect Effects Analysis" \f C
\l "4"  

	The Agency acknowledges that pesticides have the potential to exert
indirect effects upon the listed organisms by perturbing forage or prey
availability or altering the extent and nature of nesting habitat, for
example.  In conducting a screen for indirect effects, the Agency uses
the direct effects LOCs for each taxonomic group to make inferences
concerning the potential for indirect effects upon listed species that
rely upon non-endangered organisms in these taxonomic groups as
resources critical to their life cycle.

	For chloropicrin, direct effect LOCs are exceeded for mammals, fish and
aquatic invertebrates, as indicated above.  Birds may be as sensitive as
mammals.  Also, since chloropicrin is intended to kill certain target
terrestrial invertebrates, it could also potentially have a direct
effect on nontarget terrestrial invertebrates.  It also has some
phytotoxicity potential on treated sites, and thus, might also have some
potential for phytotoxicity off-site.  In addition to these potential
direct effects, there may thus be a potential for indirect effects to
those listed species that are dependent upon mammals, birds, fish,
aquatic invertebrates, terrestrial invertebrates, and/or plants. 

		F.  Critical Habitat  TC "F.  Critical Habitat" \f C \l "4"  

	 In the evaluation of pesticide effects on designated critical habitat,
consideration is given to the physical and biological features
(constituent elements) of a critical habitat identified by the U.S Fish
and Wildlife and National Marine Fisheries Services as essential to the
conservation of a listed species and which may require special
management considerations or protection.   The evaluation of impacts for
a screening level pesticide risk assessment focuses on the biological
features that are constituent elements and is accomplished using the
screening-level taxonomic analysis (risk quotients, RQs) and listed
species levels of concern (LOCs) that are used to evaluate direct and
indirect effects to listed organisms.

	The screening-level risk assessment has identified potential concerns
for indirect effects on listed species for those organisms dependant
upon mammals, birds, fish, aquatic invertebrates, terrestrial
invertebrates, and/or plants.   In light of the potential for indirect
effects, the next step for EPA and the Service(s) is to identify which
listed species and critical habitat are potentially

 implicated.  Analytically, the identification of such species and
critical habitat can occur in either of two ways.  First, the agencies
could determine whether the action area overlaps critical 

habitat or the occupied range of any listed species.  If so, EPA would
examine whether the pesticide's potential impacts on non-endangered
species would affect the listed species indirectly or directly affect a
constituent element of the critical habitat.  Alternatively, the
agencies could determine which listed species depend on biological
resources, or have constituent elements that fall into, the taxa that
may be directly or indirectly impacted by the pesticide.  Then EPA would
determine whether use of the pesticide overlaps the critical habitat or
the occupied range of those listed species.  At present, the information
reviewed by EPA does not permit use of either analytical approach to
make a definitive identification of species that are potentially
impacted indirectly or critical habitats that is potentially impacted
directly by the use of the pesticide.  EPA and the Service(s) are
working together to conduct the necessary analysis.

	This screening-level risk assessment for critical habitat provides a
listing of potential biological features that, if they are constituent 
elements of one or more critical habitats, would be of potential
concern.  These correspond to the taxa identified above as being of
potential concern for indirect effects and includes mammals, birds,
fish, aquatic invertebrates, terrestrial invertebrates, and/or plants.  
This list should serve as an initial step in problem formulation for
further assessment of critical habitat impacts outlined above, should
additional work be necessary. 

		G.  Co-occurrence Analysis  TC "G.  Co-occurrence Analysis" \f C \l
"4"  

	The goal of the analysis for co-location is to determine whether sites
of pesticide use are geographically associated with known locations of
listed species.  At the screening level, this analysis is accomplished
using the LOCATES database.  The database uses location information for
listed species at the county level and compares it to agricultural
census data for crop production at the same county level of resolution. 
The product is a listing of federally listed species that are located
within counties known to produce the crop upon which the pesticide will
be used.  Because the Level I screening assessment considers both direct
and indirect effects across generic taxonomic groupings, it is not
possible to exclude any taxonomic group from a LOCATES database run for
a screening risk assessment.  

Because chloropicrin is registered for preplant use on all
“terrestrial food crops” (as well as ornamental and other sites),
essentially all use sites from LOCATES would have to be selected.  As
indicated above, for a screen for both direct and indirect effects, all
taxonomic groups would also have to be selected.  Thus, a printout would
essentially include all known federally-listed species for all taxonomic
groups in all counties with agriculture.  If the registrants are able to
limit labels to a more narrow set of crops, a more narrow set of
counties and species can be developed.  If this is not done, the
species-specific analysis will have to include virtually all known
federally-listed species for all taxonomic groups in all counties with
agriculture.

The registrants must provide information on the proximity of
federally-listed mammals, birds, fish, aquatic invertebrates,
terrestrial invertebrates, and plants to the registered use sites.  This
requirement may be satisfied in one of three ways: 1) having membership
in the FIFRA 

Endangered Species Task Force (Pesticide Registration [PR] Notice
2000-2); 2) citing FIFRA Endangered Species Task Force data; or 3)
independently producing these data, provided the information is of
sufficient quality to meet FIFRA requirements.  The information will be
used by the OPP Endangered Species Protection Program to develop
recommendations to avoid adverse effects to listed species. 

V. Literature Cited  TC "V. Literature Cited" \f C \l "1"  

Barry TA; Segawa R; Wofford P; Ganapathy C.  1997.  Off-site air
monitoring following methyl bromide chamber and warehouse fumigations
and evaluation of the Industrial Source Complex-Short Term 3 Air
Dispersion Model. Chapter 14 in Fumigants: Environmental Fate, Exposure
and Analysis, ACS Symposium Series 652.  Editors JN Seiber et al.
American Chemical Society: Washington D.C., pp. 178 - 88.

Burns, L.A. 2002.  Exposure Analysis Modeling System (EXAMS): User
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U.S. Environmental Protection Agency, Research Trianglr Park, NC 27711. 
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http://www.epa.gov/ceampubl/swater/exams/index.htm 

Carsel, RF; Imhoff, JC; Hummel, PR; Cheplick, JM; and Donigian, AS Jr.
1998. PRZM-3, A Model for Predicting Pesticide and Nitrogen Fate in the
Crop Root and Unsaturated Soil Zones: Users Manual for Release 3.0.
National Exposure Research Laboratory, Office of Research and
Development, U.S. Environmental Protection Agency, Athens, GA.

  HYPERLINK http://www.epa.gov/ceampubl/gwater/przm3/index.htm
http://www.epa.gov/ceampubl/gwater/przm3/index.htm 

Carter, W.P.L., D. Luo, and I.L. Malkina. 1997. Investigation of the
Atmospheric Reactions of Chloropicrin. Atmospheric Environment.
31:1425-1439.

CARB (California Air Resources Board).2005. Report for Air Monitoring
Around a Bed Fumigation for Chloropicrin in Santa Cruz County, 2003.
California Environmental Protection Agency Air Resources Board,
Sacramento, Ca.   HYPERLINK
http://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm
http://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm 

CARB (California Air Resources Board). 2004. Ambient Air Monitoring for
Chloropicrin and Breakdown Products of Metam Sodium in Monterey and
Santa Cruz Counties , Fall 2001.  California Environmental Protection
Agency Air Resources Board, Sacramento, Ca.   HYPERLINK www
http://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm 

CARB (California Air Resources Board). 2003a. Ambient Air Monitoring for
Chloropicrin and Breakdown Products of Metam Sodium in Kern County ,
Summer 2001.  California Environmental Protection Agency Air Resources
Board, Sacramento, Ca.   HYPERLINK
http://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm
http://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm 

Carr, R. S.  1987.  Memorandum: 71 pp. (ECOTOX Reference #17308).

CDC (Center for Disease Control). 2004. Brief Report: Illness Associated
with Drift of Chloropicrin Soil Fumigant into a Residential Area -- Kern
County, California, 2003. Morbidity and Mortality Weekly Report. Aug.
20, 2004. 53:740-742.   HYPERLINK
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5332a4.htm
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5332a4.htm 

CDPR (California Department of Pesticide Regulation. 2003. Semiannual
report summarizing the reevaluation status of pesticide products during
the period of January 1, 2003 through June 30, 2003. CEPA Dept. Of
Pesticide Registration, Sacramento,    HYPERLINK http://
http://www.cdpr.ca.gov/docs/canot/ca03-4.htm 

CEPA (California Air Resources Board). 2003b. Report for Air Monitoring
Around a Bed Fumigation of Chloropicrin Fall 2001.  California
Environmental Protection Agency Air Resources Board, Sacramento, Ca. htt
 HYPERLINK
http://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm
p://www.cdpr.ca.gov/docs/empm/pubs/tac/studies/chlrpicrin.htm 

Chickos J.S. and W. E. Acree. 2003. Enthalpies of vaporization of
organic and organometallic compounds. 1880-2002. J Phys Chem Ref Data
32: 519-853.

Ecotoxnet. 2001. Chloropicrin.   HYPERLINK
http:/pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/chloro
picrin.
http:/pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/chloro
picrin. 

Fuller, E. N., P. D. Schettler and J.C. Giddings. 1966. A new method for
prediction of binary gas-phase diffusion coefficients. Ind Eng Chem 58:
19-27.

Gan, J., S.R. Yates, F.F. Ernst, and W.A. Jury. 2000. Degradation and
volatilization of the fumigant chloropicrin after soil treatment. J.
Environ. Qual. 29:1991-1397.

Grosjean, D. 1991. Atmospheric chemistry of toxic contaminants. Four
saturated halogenated aliphatics:methyl bromide, epichlorohydrin,
phosgene. J Air Waste 1:56-61.

Helas, G. And S. Wilson, 1992. On sources and sinks of phosgene in the
troposphere. Atmos. Envir. 26A:2975-2982

Kawamoto, K. and K. Uraro. 1989. Parameters for predicting fate of
organochlorine pesticides in the environment (II) Adsorption constant to
soil. Chemosphere 19: 1223-1231.

Kollman, W.S. 1990. Literature review of the Environmental Fate of
Chloropicrin. Memorandum to R.S. Segawa, Environmental Hazards
Assessment Program , California Dept. Of Food and Agriculture. 9 pp.

Lee, S., R. McLaughlin, M. Hardly, R. Gunier, and Richard Kreutzer.
2002. Community Exposures to Airborne Agricultural Pesticides in
California: Ranking of Inhalation Risks. Environmental Health
Perspectives. 110:1175 - 1184.

Maddy, K.T., D. Gibbons, D.M. Richmond, and A.S. Fredrickson. 1983. A
study of the levels of methyl bromide and chloropicrin in the air
downwind from a field during and after a preplant fumigation (shallow
injection) - a preliminary report. CDFA, Division of Pest Management,
Environmental Protection and Worker Safety, Worker Health and Safety
Unit. Report No. HS-1061

Maddy, K.T., D. Gibbons, D.M. Richmond, and A.S. Fredrickson. 1984.
Additional monitoring of the concentrations of methyl bromide and
chloropicrin in the air downwind from a field during and after a
preplant fumigation (shallow injection) - a preliminary report. CDFA,
Division of Pest Management, Environmental Protection and Worker Safety,
Worker Health and Safety Unit. Report No. HS-1183

Manoque, W. And R. Pigford. 1960. The kinetics of the absorption of
phosgene into water and aqueous solutions. A.I. Ch. E, Journal
6:494-500.

Merck Index - Encyclopedia of Chemicals, Drugs and Biologicals. 
Budavari, S (ed.).  Rahway, NJ; Merck and Co., Inc., 1989. 333.

MRID# 05007865. Moilanen, K.W., D.G. Crosby, J.R. Humphrey, and J.W.
Giles. 1978.  Vapor phase photodecomposition of chloropicrin
(trichloronitromethane).  Tetrahedron. 34:3345-3349.

MRID# 42900201. Moreno, T., and H. Lee.  1993.  Photodegradation of
chloropicrin.  Laboratory Project ID: BR 389.1:93.  Unpublished study
performed by Bolsa Research Associates, Inc., Hollister, CA, and
submitted by Chloropicrin Manufacturers Task Force.

1989.  Hydrolysis study with chloropicrin as a function of pH at 25̊C. 
Laboratory Project ID.: B.R. 51:89. Unpublished study performed by Bolsa
Research Associates, Hollister, CA, and submitted by The Chloropicrin
Industry Panel, West Lafayette, IN

MRID# 43085101. Ivancovich, A.  1987.  Chloropicrin - Field dissipation
study.  Laboratory Project ID: BR11:87.1.  Unpublished study performed
by Bolsa Research Associates, Hollister, CA, and submitted by the
Chloropicrin Industry Panel.

MRID# 43613901 Hatton C., K. Shepler, and L. Ruzo.  1995.  Aerobic soil
metabolism of [14C]chloropicrin.  PTRL Report No.:  448W-1.  PTRL
Project No.:  448W.  Unpublished study performed by PTRL West Inc.,
Richmond, CA; and submitted by Chloropicrin Manufacturers Task Force,
c/o Niklor Chemical company, Long Beach, CA. 

MRID# 43759301. Hatton, C., K. Shepler, and L. Ruzo.  1995.  Anaerobic
aquatic metabolism of [14C]chloropicrin.  PTRL Report No.:  449W-1. 
PTRL Project No.:  449W.  Unpublished study performed by PTRL West,
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MRID# 43798601. Skinner, W., and N. Jao.  1995.  Laboratory volatility
of [14C]chloropicrin.  PTRL Report No.:  450W-1.  PTRL Project No.: 
450W.  Unpublished study performed by PTRL West, Inc., Richmond, CA; and
submitted by The Chloropicrin Manufacturers Task Force, c/o Niklor
Chemical Company, Long Beach, CA. 

MRID# 44191301.  Skinner, W.  1996.  Soil column leaching of
[14C]chloropicrin in four soil types.  PTRL Report No.:  587W-1.  PTRL
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Richmond, CA; and submitted by The Chloropicrin Manufacturers Task
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Pe4 Shell.  2004.  Environmental Fate and Effects Division, Office of
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Sadtler Research Laboratories.1980. Standard Spectra Collection. Sadtler
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Scheer, V., A. Frenzel, W. Behnke, C. Zetzsch, L. Magi, Ch. George, and
Ph. Mirabel. 1997.Uptake of Nitrosyl Chloride (NOCL) by Aqueous
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Singh H.B. 1976. Phosgene in the ambient air. Nature. 264:428-429.

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USEPA.  1998a.  Guidelines for Ecological Risk Assessment. Published on
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U.S. EPA (United States Environmental Protection Agency). 2004. Health
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VI. Appendices  TC "VI. Appendices" \f C \l "1"  

	Appendix A.  Environmental Fate and Transport Data  TC "Appendix A. 
Environmental Fate and Transport Data" \f C \l "2"  

161-1 Hydrolysis (MRID# 43022401)

Chloropicrin, at approximately 100 ppm, did not hydrolyze in sterile
aqueous buffered solutions adjusted to pH 5, 7, and 9, that were
incubated in the dark at 25°C.During the 28 day study, chloropicrin
ranged from 106.4 to 113.8 ppm in the pH 5 acetate buffer solution, from
97.3 to 113.7 ppm in the pH 7 phosphate buffer solution, and from 101.6
to 111.1 ppm in the pH 9 phosphate buffer solution.  No pattern of
decline was noted in any set of samples.  In all samples, inorganic
chloride was <1.5 ppm.  The pH of the buffer solutions remained stable
throughout the study.

161-2	Aqueous Photolysis (MRID# 42900201)

The Chloropicrin Manufacturers’ Task Force responded to several EPA
questions (pp. 37-38 of Comments on USEPA’s Chloropicrin Risk
Assessment Phase 3, February 28, 2007; FRL: 8087-4;
EPA-HQ-OPP-2006-0661).  EPA concluded that the study provided only
limited supplemental information on photohydrolysis of chloropicrin due
to problems in the study related to the material balance.  The
registrant responded that the results of this study were comparable to
other available data on aqueous photolysis and reported the following
examples.  Castro and Belser (1981) determined that the photohydrolytic
half-life of a 10-3M solution of chloropicrin was ca. 5 hours (Castro,
C.E., and N.O.Belser. 1981. Photohydrolysis of methyl bromide and
chloropicrin. J. Agric. Food Chem. 29:1005-1008).  

This study was previously (DER 10/20/94) determined to be unacceptable. 
The following significant deviation was noted: it was not possible to
ascertain if the material balances were complete (material balances were
calculated by the study authors from information provided in summary
tables); however, various results within the summary tables differed
considerably from the results reported in the raw data. Even though the
study shows a number of deficiencies, some useful information can be
derived from it. This study is classified as supplemental.

161-3 Photodegradation on Soil (Waived)

This study was waived because chloropicrin is used by soil injections,
therefore, no substantial soil photolysis is expected.

161-4 Photolysis in Air (MRID# 05007865)

e photolytic half-life of chloropicrin vapor is about 20 days at
25-30̊C.  The photolysis rate decreased markedly after 20 days.  The
photodegradation appears to be dependent on the presence of oxygen.  The
initial photoproducts and the incorporation of 18O2 suggest an
intramolecular rearrangement involving the trioxazole N-oxide as an
intermediate.  In the dark control, the concentration of chloropicrin
decreased slightly over 70 days.

Chloropicrin vapor is readily photodegraded to phosgene (COCl2) and
nitrosyl chloride (NOCl) under simulated sunlight.  COCl2 is not further
degraded, but NOCl subsequently is photodegraded to nitrous oxide (NO)
and chlorine (Cl2).  A portion of the NO is oxidized to nitrogen dioxide
(NO2) and dinitrogen tetraoxide (N2O4).

A degradation pathway was postulated by the registrant:  In nitrogen
atmosphere, chloropicrin was stable to irradiation, indicating that O2
is required for photodecomposition, and suggesting that an intermediate,
trioxazole N-oxide, was involved, that decomposes to COCl2, NOCl, and
O2.

 

162-1 Aerobic Soil Metabolism (MRID# 43613901)

The Chloropicrin Manufacturers’ Task Force responded to several EPA
questions (pp. 37-38 of Comments on USEPA’s Chloropicrin Risk
Assessment Phase 3, February 28, 2007; FRL: 8087-4;
EPA-HQ-OPP-2006-0661).

The study was conducted in a sealed system with positive oxygen pressure
to maintain aerobicity due to concerns for the material balance
considering chloropicrin’s volatility   Moisture adjustments could not
made without losing the volatile radiocarbon.     

Soil population of bacteria, actinomycetes and fungi decreased in days
12-15, but recovered significantly by 26-29 days.

The PUF trap was located in the sidearm between the soil and the base
trap.

Soil was collected from the Watsonville, California area, a typical
strawberry cultivation region, from a target zone of 0-18 inches. 
According to the study director’s recollection, chloropicrin was
introduced to the test soil at the maximum possible depth.

In reformatting the original DER into the current harmonized templates
used by EPA, the current reviewer calculated the aerobic soil metabolism
half-life for chloropicrin using the data provided in the original DER
and the current EFED methods using all data points:  first-order linear
regression using Excel 2000, and single, two-parameter exponential decay
non-linear regression using SigmaPlot v. 9.  The current reviewer
obtained a linear half-life of 3.7 days and a non-linear half-life of
0.2 days; the study author calculated DT50 was 4.5 days and the observed
DT50 was ca. 4 hours. Because of the volatile nature of chloropicrin,
the reviewer also calculated a half-life for the total system.  The
half-life for the total system was 4.4 days.

Reexamination of the study results reveals that volatilization, in the
soil environment, will be the major dissipation route of chloropicrin.
Due to the fact that volatilization is significant and occurs rapidly,
the importance of other competing processes such as leaching,
biodegradation, and adsorption to the soil particles will certainly
depend on expected field volatility. This is because volatility
determines the amount of chloropicrin left for other processes and its
residence time in the soil system. This study is classified as
acceptable.

162-3 Anaerobic Aquatic Metabolism (MRID# 43759301, supplemental)

The Chloropicrin Manufacturers’ Task Force submitted comments to EPA
regarding the Phase 3 Risk Assessment for Chloropicrin.  In these
comments, the Task Force cites that EPA calculated an anaerobic aquatic
metabolism half-life of 0.05 days (methods not described) for
chloropicrin (p. 29 of Comments on USEPA’s Chloropicrin Risk
Assessment Phase 3, February 28, 2007; FRL: 8087-4;
EPA-HQ-OPP-2006-0661).  

EPA indicated that this study did not meet Subdivision N Guidelines due
to two problems:  The test water was not representative of the intended
use site (purified deionized water was utilized to flood the soil
samples); and the analytical methods were inadequate for the
characterization of the residues in water samples removed at later
sampling intervals (low column recoveries in the HPLC analysis).  The
Chloropicrin Manufacturers’ Task Force responded to these two problems
(p. 38 of Comments on USEPA’s Chloropicrin Risk Assessment Phase 3,
February 28, 2007; FRL: 8087-4; EPA-HQ-OPP-2006-0661):

Because chloropicrin has no aquatic uses, the primary mode of
interaction with water will be chloropicrin in/on soil exposed to
rainwater.  Therefore, soil from a growing region and deionized water
were used, rather than sediment and natural water.  Suitability of the
test system was characterized throughout the study by measuring pH, Eh,
and dissolved oxygen.  

The analytical methods were consistently successful in identifying and
quantitating a variety of volatile, water soluble species isolated from
aqueous and soil matrices.  Loss of material from water column
recoveries was ascribed to the formation of methanol as a degradate,
which is a volatile material and probably accounts for these low
recoveries.

In reformatting the original DER into the current harmonized templates
used by EPA, the current reviewer calculated the anaerobic aquatic
metabolism half-life for chloropicrin using the data provided in the
original DER and the current EFED methods using all data points: 
first-order linear regression using Excel 2000, and single,
two-parameter exponential decay non-linear regression using SigmaPlot v.
9.  The current reviewer obtained a total system linear half-life of 0.4
days (9.6 hours) and a non-linear half-life of 0.03 days (0.7 hours);
the study author calculated DT50 was 0.05 days (1.3 hours), and the
observed DT50 was <0.06 days (<1.5 hours). This study is classified as
acceptable.

163-1 Mobility - Column Leaching (MRID# 44191301)

This study is classified as supplemental.  The temperature used during
the leaching phase was not reported.  Also, t  SEQ CHAPTER \h \r 1 he
method used to maintain a constant column head during leaching of the
soil column was not reported. Additional comments can be found on page
14-15 of revised Data evaluation record for column leaching.

  SEQ CHAPTER \h \r 1 The column leaching of unaged [14C]-labeled
trichloronitromethane (chloropicrin) was investigated in four U.S.
soils: a sandy loam soil [pH 7.2, organic carbon 0.75%] from California,
a loamy sand soil [pH 7.2, organic carbon 0.03%] from California, a silt
loam soil [pH 6.6, organic carbon 1.02] from Maryland, and a silty clay
loam soil [pH 5.8, organic carbon 1.11%] from Kentucky.  This study was
conducted in accordance with USEPA Subdivision N, Section 163-1.  Good
Laboratory Practice guidelines were not provided.  Air-dried and sieved
(2 mm) test soils were added to glass columns (2 inch i.d.) up to a
height of 48 cm and saturated with 0.01M CaCl2 solution.  A soil column
tracer (pentafluorobenzoic acid) was injected six inches below the soil
surface of each column.  The columns were treated with unlabeled and
[14C]-labeled chloropicrin, dissolved in acetonitrile, at nominal
application rates of 345 lb/A (two sandy loam soil columns; all loamy
sand and silt loam soil columns) and 362 lb/A (two sandy loam soil
columns; all silty clay loam soil columns).  [14C]Volatiles were trapped
using water vapor, methanol, activated charcoal, and 10% KOH traps. 
Each column was leached in darkness with 1030 mL (20 in.) of 0.01M CaCl2
solution over a period of 17-138 hours (sandy loam soil), 1-1.5 hours
(loamy sand soil), 126-132 hours (silt loam soil), and 101-116 hours
(silty clay loam soil; temperature and infiltration rate not reported). 

During leaching, leachate volumes were collected and analyzed using LSC.
 To determine if 14CO2 was present, select leachates from the sandy loam
soil were analyzed by LSC using cocktail that retains 14CO2, and the
results were compared with those from the original LSC analysis.  Select
leachate samples from the silt loam soil were precipitated with BaCl2
and analyzed by LSC following combustion.  Aliquots of the headspace gas
from select leachate containers were also analyzed by LSC following
combustion.  Results indicated that 14CO2 was not present in the
leachate solution.  To quantitate 14CO2, an aliquot of the headspace gas
was trapped in 10% KOH and analyzed by LSC.  To characterize
[14C]residues, an aliquot of the headspace gas was trapped in
acetonitrile and analyzed by LSC.  

Following leaching, the soil columns were divided into eight 6 cm
sections, extracted twice with acetonitrile, centrifuged, and the
extracts were decanted, combined, and analyzed by LSC.  Subsamples of
post-extracted soil were analyzed by LSC following combustion.  Selected
subsamples of post-extracted soil (silt loam and silty clay loam) were
extracted by shaking with 0.5M NaOH, centrifuged, and acidified (pH 1,
6N HCl; humic acid fraction), then centrifuged and analyzed by LSC
(fulvic acid fraction).  The remaining precipitate was redissolved in
0.5M NaOH and analyzed by LSC (humic acid fraction).  Aliquots of the
headspace gas from selected soil extract containers were analyzed by LSC
following combustion.  Results indicated that <0.05% of the applied
radioactivity was present in the headspace.

Aliquots of the KOH and methanol trapping solutions were analyzed for
total radioactivity using LSC.  The 14CO2 in select traps (KOH traps
containing >1% of the applied) was precipitated with BaCl2 and analyzed
by LSC; results indicated that 92.7-99.9% of the applied radioactivity
in the traps was 14CO2.  Aliquots of the charcoal traps were analyzed by
LSC following combustion.  Subsamples of charcoal traps containing >1%
of the applied radioactivity were extracted with acetonitrile:water
(9:1, v:v), centrifuged, further extracted with methylene chloride and
analyzed by LSC.

Leachates, soil extracts, and trapping solutions were analyzed for
[14C]chloropicrin using reverse-phase HPLC analysis.  The samples were
co-chromatographed with nonradiolabeled reference standards of
chloropicrin, nitromethane, and pentafluorobenzoic acid.  To identify
dichloromethylhydroxylamine and nitromethane, the leachate from a single
silty clay loam soil column was further analyzed by LC/MS and
ion-exclusion HPLC analysis, respectively.  To confirm compound
identities, select leachate solutions and volatile components were
further analyzed by GC/MS analysis.

For the sandy loam soil, mass balances were 90.9-108.4% of the applied
radioactivity.  Most of the [14C]residues retained in the soil column
were detected at 30- to 48-cm (16.0%).  Residues were also detected at
12- to 30-cm (9.4%) and were not detected above 12- to 18-cm. 
Chloropicrin was detected at 4.0% of the applied at 12- to 24-cm, 6.9%
at 24- to 36-cm, and 10.0% at 36- to 48-cm.  Minor transformation
products dichloronitromethane and nitromethane were detected at 1.0%
(42-to 48-cm; one of three columns) and 0.5% (24- to 36-cm; one of three
columns) of the applied.  Two unidentified minor transformation products
(designated as D2 and D3) were each present at (0.2% of the applied at
12- to 48-cm.  Uncharacterized radioactivity (designated “all
others”) was detected at 0.2% (12- to 24-cm; two of three columns) of
the applied.  Nonextractable [14C]residues were a maximum of 1.0% of the
applied at 12- to 18-cm.

Total [14C]residues in the leachate solution were 30.8% of the applied
radioactivity (reviewer-calculated mean).  Chloropicrin was present at
17.2% of the applied.  Minor transformation products
dichloromethylhydroxylamine, dichloronitromethane, and nitromethane were
7.3%, 5.0%, and 3.7% (one of three column leachates) of the applied,
respectively.  [14C]Organic volatiles in the leachate headspace
accounted for 5.6% of the applied; chloropicrin and
dichloromethylhydroxylamine accounted for 4.6% and 1.0% of the applied,
respectively.  Evolved 14CO2 in the leachate headspace was 0.9% of the
applied.  Evolved 14CO2 (bottom of the column) was 1.0% of the applied
radioactivity.  [14C]Organic volatiles (bottom of the column) were 32.8%
of the applied; chloropicrin accounted for 32.4% of the applied. 
Evolved 14CO2 and [14C]organic volatiles were not detected at the top of
the column.

For the loamy sand soil, mass balances were 91.2-96.9% of the applied
radioactivity.  Most of the [14C]residues retained in the soil column
were detected at 12- to 18-cm (22.6%).  Residues were also detected at
18- to 48-cm (8.4%) and were not detected above 12- to 18-cm. 
Chloropicrin was detected at 36.6% (two of three columns) of the applied
at 12- to 24-cm and was 8.6% (two of three columns) of the applied at
24- to 48-cm.  Transformation products were not detected. 
Uncharacterized radioactivity (designated “all others”) was detected
at 0.3% (one of three columns) of the applied at 12- to 48-cm. 
Nonextractable [14C]residues were 0.1% of the applied at 18- to 48-cm.

Total [14C]residues in the leachate solution were 43.7% of the applied
radioactivity.  Chloropicrin was present at 42.7% of the applied.  Minor
transformation products dichloronitromethane and
dichloromethylhydroxylamine were 0.77% and 0.35% (two of three column
leachates) of the applied, respectively.  Uncharacterized radioactivity
(designated “all others”) was detected at 0.1% (one of three column
leachates) of the applied.  [14C]Organic volatiles in the leachate
headspace accounted for 4.8% of the applied; chloropicrin accounted for
4.8% of the applied.  Evolved 14CO2 in the leachate headspace was 1.5%
of the applied.  Evolved 14CO2 (bottom of the column) was 0.33% of the
applied radioactivity.  [14C]Organic volatiles (bottom of the column)
were 12.2% of the applied; chloropicrin accounted for 12.2% of the
applied.  Evolved 14CO2 and [14C]organic volatiles were not detected at
the top of the column.

For the silt loam soil, mass balances were 90.3-92.6% of the applied
radioactivity.  Most of the [14C]residues retained in the soil column
were detected at 36- to 48-cm (13.5%).  Residues were also detected at
6- to 36-cm (16.9%) and were not detected above 6- to 12-cm. 
Chloropicrin was detected at 0.1% of the applied at 12- to 48-cm.  Minor
transformation product dichloromethylhydroxylamine was 0.26% of the
applied at 12- to 30-cm, 0.7% at 30- to 42-cm, and 0.63% at 42- to
48-cm.  Minor transformation product dichloronitromethane was 0.1% (one
of three columns) of the applied at 12- to 30-cm, 0.25% at 30-to 42-cm,
and 0.1% at 42- to 48-cm.  Minor transformation product nitromethane was
detected at 0.1% (one of three columns) of the applied at 12- to 30-cm. 
Two unidentified minor transformation products, D2 and D3, were each
present at (0.33% of the applied at 12- to 48-cm.  Uncharacterized
radioactivity (designated “all others”) was (0.17% of the applied at
12- to 48-cm.  Nonextractable [14C]residues were a maximum of 5.0-5.7%
of the applied at 30- to 48-cm; [14C]residues associated with humic
acid, fulvic acid, and humin fractions of a selected soil column were
0.19-0.38%, 0.94-2.8%, and 1.9-4.1% of the applied, respectively, at 12-
to 48-cm.

Total [14C]residues in the leachate solution were 31.6% of the applied
radioactivity.  Chloropicrin was present at 1.1% of the applied.  Major
transformation products dichloromethylhydroxylamine and
dichloronitromethane were present at 16.4% and 10.9% of the applied,
respectively.  Minor transformation product nitromethane was detected at
2.5% of the applied.  Uncharacterized radioactivity (designated “all
others”) was 0.7% of the applied.  [14C]Organic volatiles in the
leachate headspace accounted for 4.5% of the applied; chloropicrin and
dichloromethylhydroxylamine accounted for 0.1% and 4.4% of the applied,
respectively.  Evolved 14CO2 in the leachate headspace was 0.4% of the
applied.  Evolved 14CO2 (bottom of the column) was 4.6% of the applied
radioactivity.  [14C]Organic volatiles (bottom of the column) were 17.8%
of the applied; chloropicrin and dichloronitromethane accounted for
13.8% and 3.3% of the applied, respectively.  Evolved 14CO2 and
[14C]organic volatiles were not detected at the top of the column.

163-2 Laboratory Volatility (MRID# 43798601)

The Chloropicrin Manufacturers’ Task Force responded to several EPA
questions (pp. 39-40 of Comments on USEPA’s Chloropicrin Risk
Assessment Phase 3, February 28, 2007; FRL: 8087-4;
EPA-HQ-OPP-2006-0661).

Time zero analysis of the treated soil was not conducted because the
volatility of chloropicrin would likely have resulted in an inaccurate
estimation of the dose had the soil been extracted for analysis at time
zero.      

Since radiolabeled test substance was used and the material balance
recoveries for tarped and non-tarped soils in this study were 97% of the
applied, trapping efficiency was considered adequate.  

The estimated field wind speeds that correspond to the 7.5 air
exchanges/hour of the test system were calculated for three
square-shaped field sizes to relate the flow rate (100 mL/min) to total
exchanges during actual practice under greenhouse and field conditions:

1-acre field (208 sq. ft.):  For 7.5 air exchanges/hour, the wind
velocity equivalent would be 1560 ft/hr or 0.1321 m/sec (0.295 mph).

10-acre field (660 sq. ft.):  For 7.5 air exchanges/hour, the wind
velocity equivalent would be 4950 ft/hr or 0.14191 m/sec (0.938 mph).

40-acre field (1320 sq. ft.):  For 7.5 air exchanges/hour, the wind
velocity equivalent would be 9900 ft/hr or 0.8382 m/sec (1.875 mph).

This laboratory volatility study is scientifically valid. It provides
useful information on the volatility of chloropicrin in a sandy loam
soil. However, it appears that the flow exchange rate is high compared
to actual use conditions. This study is acceptable as it meets
Subdivision N Guidelines for the fulfillment of EPA data requirements on
laboratory volatility.  

164-1 Terrestrial Field Dissipation (MRID# 43085101, supplemental)

During the chloropicrin risk assessment phase 3 process, Agency received
responses from the Chloropicrin Manufactures’ Task Force (CMTF)
regarding the review comments on terrestrial field dissipation study.
The Chloropicrin Manufacturers’ Task Force responded to several EPA
questions (pp. 40-42 of Comments on USEPA’s Chloropicrin Risk
Assessment Phase 3, February 28, 2007; FRL: 8087-4;
EPA-HQ-OPP-2006-0661). The responses are listed below.

Only soil air samples were collected because it was not possible to
collect soil samples that would adequately reflect the amount of
chloropicrin adsorbed/absorbed on soil particles under field conditions
at any given time.  Any soil disturbance (soil core collection) would
immediately release the chloropicrin, a volatile fumigant, from the
soil, where it partitions reversibly between soil and air compartments
in which a decline in the vapor phase represents a decline in the soil
phase (MRID 43613901).  The field dissipation study represents the
cumulative effect of the off-gassing and degradation of chloropicrin
during actual field fumigation practices.  Therefore, given the high
volatility, rapid soil degradation and low affinity for sorption on
soil, analysis for metabolites or degradates under field conditions was
not practical and soil samples would not accurately reflect the amount
of chloropicrin in the soil phase.      

The test soil was further characterized as follows using the USDA
Natural Resource Conservation Service, National Cooperative Soil Survey
(NCSS; accessed January 2007):

Soil Characteristics	Clear Lake Clay	Baywood Loamy Sand

Sand (%)	22.1	81.1

Silt (%)	27.9	16.4

Clay (%)	50.0	2.5

Organic matter (%)	1.50	2.50

Bulk Density at 1/3 bar (g/cm3)	1.30	1.60

pH	7.9	6.5

Cation Exchange Capacity (milliequivalents/100 g)	37.5	12.5

Available Water Capacity (quantity of water soil is capable of storing:
cm/cm)	0.15	0.09

  

Meterological data was located using the University of California CIMIS
system, specifically the Castroville weather station (CIMIS #19), which
is located ca. 9 miles from from the sand soil site, and the Gilroy
weather station (NCDC #3417) located ca. 5 miles from the clay loam soil
site.  There was no irrigation applied to the plots and the soil grade
was flat (0%) slope at both sites.

Although the exact field maintenance practices at each site is not
known, the following standard soil preparation practices would not
differ significantly from 1987, when the study was conducted, to today. 
Plant residues from the previous crop, if present, would be worked into
the soil by tilling several weeks or more before the test, soil disking
would reduce clod size to an appropriate size for fumigation, and
appropriate soil moisture would be obtained by disking subsurface oil
and/or using overhead irrigation prior to fumigation.

Agency reevaluated the study considering the CMTF comments on
dissipation of chloropicrin under field conditions. Agency reviewed the
additional information provided by the CMTF and concluded that this
study remains as supplemental and can not be upgraded with additional
data.

This study provides limited supplemental information about the
terrestrial field dissipation of chloropicrin.  



	Appendix B. Aquatic Exposure PRZM/EXAMS Modeling  TC "Appendix B.
Aquatic Exposure PRZM/EXAMS Modeling" \f C \l "2"  

	This appendix documents the output from PRZM / EXAMS simulations for
each of six  location/crop scenarios: California / Onion and Tomato,
Florida / Strawberry and Tomato, and North Carolina / Tobacco and sweet
potato.  The settings for each model run are presented first, followed
by the raw data sorted by year and sorted in descending order by EEC. 
Values represent the estimated environmental concentrations (EECs) in
units of micrograms per liter (μg/L) or parts per billion (ppb).  The
1-in-10 year summary statistics for each run are presented at the very
end of the sorted results in the row assigned a probability level of
0.10.  This summary statistic was generated from a linear interpretation
of the raw data plotted using Weibull plotting positions.  This approach
is further described at the end of the appendix B-6.

B.1.1 Florida Strawberry

stored as FL_Straw.out

	Chemical: Chloropicrin

	PRZM environment: FLstrawberry_WirrigSTD.txt	modified Tueday, 29 May
2007 at 12:53:40

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

	Metfile: w12842.dvf	modified Wedday, 3 July 2002 at 10:04:28

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.00	0.00	0.00	0.00	0.00	0.00

1962	68.10	43.43	13.08	4.62	3.08	0.76

1963	25.85	15.97	5.37	1.91	1.28	0.31

1964	0.80	0.52	0.17	0.06	0.04	0.01

1965	106.00	65.71	21.64	7.67	5.11	1.26

1966	1.80	1.19	0.45	0.16	0.11	0.03

1967	2.39	1.51	0.73	0.26	0.17	0.04

1968	1.05	0.67	0.20	0.10	0.07	0.02

1969	4.71	3.07	1.24	0.48	0.32	0.08

1970	0.76	0.47	0.29	0.11	0.07	0.02

1971	1.19	0.78	0.40	0.20	0.13	0.03

1972	4.81	3.07	1.21	0.48	0.32	0.08

1973	9.13	5.77	2.01	0.72	0.48	0.12

1974	0.01	0.00	0.00	0.00	0.00	0.00

1975	9.22	5.82	2.74	1.02	0.68	0.17

1976	9.79	6.53	2.70	0.98	0.65	0.16

1977	66.55	44.23	14.18	5.02	3.35	0.83

1978	6.06	3.98	1.28	0.47	0.32	0.08

1979	12.28	9.06	3.74	1.32	0.88	0.22

1980	0.57	0.37	0.18	0.07	0.05	0.01

1981	27.92	21.03	7.51	2.66	1.77	0.44

1982	32.13	22.94	9.97	3.55	2.36	0.58

1983	4.53	2.98	1.03	0.37	0.25	0.06

1984	1.64	1.09	0.37	0.13	0.09	0.02

1985	6.26	3.96	1.45	0.53	0.35	0.09

1986	0.32	0.25	0.12	0.06	0.04	0.01

1987	1.46	0.96	0.38	0.14	0.09	0.02

1988	8.22	5.21	1.57	0.55	0.37	0.09

1989	6.95	4.52	1.67	0.62	0.41	0.10

1990	1.33	0.90	0.34	0.12	0.08	0.02

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	106.00	65.71	21.64	7.67	5.11	1.26

0.06	68.10	44.23	14.18	5.02	3.35	0.83

0.10	66.55	43.43	13.08	4.62	3.08	0.76

0.13	32.13	22.94	9.97	3.55	2.36	0.58

0.16	27.92	21.03	7.51	2.66	1.77	0.44

0.19	25.85	15.97	5.37	1.91	1.28	0.31

0.23	12.28	9.06	3.74	1.32	0.88	0.22

0.26	9.79	6.53	2.74	1.02	0.68	0.17

0.29	9.22	5.82	2.70	0.98	0.65	0.16

0.32	9.13	5.77	2.01	0.72	0.48	0.12

0.35	8.22	5.21	1.67	0.62	0.41	0.10

0.39	6.95	4.52	1.57	0.55	0.37	0.09

0.42	6.26	3.98	1.45	0.53	0.35	0.09

0.45	6.06	3.96	1.28	0.48	0.32	0.08

0.48	4.81	3.07	1.24	0.48	0.32	0.08

0.52	4.71	3.07	1.21	0.47	0.32	0.08

0.55	4.53	2.98	1.03	0.37	0.25	0.06

0.58	2.39	1.51	0.73	0.26	0.17	0.04

0.61	1.80	1.19	0.45	0.20	0.13	0.03

0.65	1.64	1.09	0.40	0.16	0.11	0.03

0.68	1.46	0.96	0.38	0.14	0.09	0.02

0.71	1.33	0.90	0.37	0.13	0.09	0.02

0.74	1.19	0.78	0.34	0.12	0.08	0.02

0.77	1.05	0.67	0.29	0.11	0.07	0.02

0.81	0.80	0.52	0.20	0.10	0.07	0.02

0.84	0.76	0.47	0.18	0.07	0.05	0.01

0.87	0.57	0.37	0.17	0.06	0.04	0.01

0.90	0.32	0.25	0.12	0.06	0.04	0.01

0.94	0.01	0.00	0.00	0.00	0.00	0.00

0.97	0.00	0.00	0.00	0.00	0.00	0.00

0.10	63.11	41.38	12.77	4.51	3.01	0.74

	Average of yearly averages:	0.19

Inputs generated by pe5.pl - Novemeber 2006

	Data used for this run:

	Output File: FL_Straw

Metfile:	w12842.dvf

	PRZM scenario:	FLstrawberry_WirrigSTD.txt

	EXAMS environment file:	pond298.exv

Chemical Name:	Chloropicrin

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	392	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-09	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.1.2 Florida Strawberry @ 175 lbs/A

stored as Untarp_St.out

	Chemical: Chloropicrin

	PRZM environment: FLstrawberry_WirrigSTD.txt	modified Tueday, 29 May
2007 at 12:53:40

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

	Metfile: w12842.dvf	modified Wedday, 3 July 2002 at 10:04:28

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.00	0.00	0.00	0.00	0.00	0.00

1962	34.04	21.71	6.54	2.31	1.54	0.38

1963	12.92	7.98	2.69	0.96	0.64	0.16

1964	0.40	0.26	0.08	0.03	0.02	0.00

1965	53.01	32.86	10.82	3.84	2.56	0.63

1966	0.90	0.59	0.22	0.08	0.05	0.01

1967	1.20	0.76	0.37	0.13	0.09	0.02

1968	0.53	0.34	0.10	0.05	0.03	0.01

1969	2.35	1.54	0.62	0.24	0.16	0.04

1970	0.38	0.24	0.14	0.05	0.04	0.01

1971	0.59	0.39	0.20	0.10	0.07	0.02

1972	2.40	1.54	0.61	0.24	0.16	0.04

1973	4.56	2.88	1.00	0.36	0.24	0.06

1974	0.00	0.00	0.00	0.00	0.00	0.00

1975	4.61	2.91	1.37	0.51	0.34	0.08

1976	4.89	3.26	1.35	0.49	0.33	0.08

1977	33.28	22.12	7.09	2.51	1.67	0.41

1978	3.03	1.99	0.64	0.24	0.16	0.04

1979	6.14	4.53	1.87	0.66	0.44	0.11

1980	0.28	0.18	0.09	0.04	0.02	0.01

1981	13.96	10.51	3.76	1.33	0.89	0.22

1982	16.06	11.47	4.99	1.77	1.18	0.29

1983	2.27	1.49	0.51	0.19	0.12	0.03

1984	0.82	0.55	0.19	0.07	0.04	0.01

1985	3.13	1.98	0.72	0.27	0.18	0.04

1986	0.16	0.12	0.06	0.03	0.02	0.00

1987	0.73	0.48	0.19	0.07	0.05	0.01

1988	4.11	2.60	0.78	0.28	0.19	0.05

1989	3.47	2.26	0.84	0.31	0.21	0.05

1990	0.66	0.45	0.17	0.06	0.04	0.01

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	53.01	32.86	10.82	3.84	2.56	0.63

0.06	34.04	22.12	7.09	2.51	1.67	0.41

0.10	33.28	21.71	6.54	2.31	1.54	0.38

0.13	16.06	11.47	4.99	1.77	1.18	0.29

0.16	13.96	10.51	3.76	1.33	0.89	0.22

0.19	12.92	7.98	2.69	0.96	0.64	0.16

0.23	6.14	4.53	1.87	0.66	0.44	0.11

0.26	4.89	3.26	1.37	0.51	0.34	0.08

0.29	4.61	2.91	1.35	0.49	0.33	0.08

0.32	4.56	2.88	1.00	0.36	0.24	0.06

0.35	4.11	2.60	0.84	0.31	0.21	0.05

0.39	3.47	2.26	0.78	0.28	0.19	0.05

0.42	3.13	1.99	0.72	0.27	0.18	0.04

0.45	3.03	1.98	0.64	0.24	0.16	0.04

0.48	2.40	1.54	0.62	0.24	0.16	0.04

0.52	2.35	1.54	0.61	0.24	0.16	0.04

0.55	2.27	1.49	0.51	0.19	0.12	0.03

0.58	1.20	0.76	0.37	0.13	0.09	0.02

0.61	0.90	0.59	0.22	0.10	0.07	0.02

0.65	0.82	0.55	0.20	0.08	0.05	0.01

0.68	0.73	0.48	0.19	0.07	0.05	0.01

0.71	0.66	0.45	0.19	0.07	0.04	0.01

0.74	0.59	0.39	0.17	0.06	0.04	0.01

0.77	0.53	0.34	0.14	0.05	0.04	0.01

0.81	0.40	0.26	0.10	0.05	0.03	0.01

0.84	0.38	0.24	0.09	0.04	0.02	0.01

0.87	0.28	0.18	0.08	0.03	0.02	0.00

0.90	0.16	0.12	0.06	0.03	0.02	0.00

0.94	0.00	0.00	0.00	0.00	0.00	0.00

0.97	0.00	0.00	0.00	0.00	0.00	0.00

0.10	31.56	20.69	6.38	2.25	1.50	0.37

	Average of yearly averages:	0.09

Inputs generated by pe5.pl - Novemeber 2006

	Data used for this run:

Output File: Untarp_St

	Metfile:	w12842.dvf

	PRZM scenario:	FLstrawberry_WirrigSTD.txt

	EXAMS environment file:	pond298.exv

Chemical Name:	Chloropicrin

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	196	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-09	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.1.3Florida Tomato

stored as FLTomato.out

	Chemical: Chloropicrin

	PRZM environment: FLtomatoSTD.txt	modified Tueday, 29 May 2007 at
12:54:10

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

	Metfile: w12844.dvf	modified Wedday, 3 July 2002 at 10:04:30

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	2.80	1.74	0.81	0.31	0.21	0.05

1962	79.16	55.20	18.29	6.44	4.30	1.06

1963	41.72	34.00	17.30	6.46	4.31	1.06

1964	42.58	29.91	13.60	4.96	3.31	0.81

1965	6.58	3.75	1.67	0.79	0.53	0.13

1966	19.91	13.50	5.61	2.09	1.39	0.34

1967	65.51	41.73	14.15	5.17	3.44	0.85

1968	26.19	19.20	10.82	3.98	2.65	0.65

1969	33.45	21.04	11.46	4.18	2.79	0.69

1970	18.22	11.15	4.77	1.71	1.14	0.28

1971	2.34	1.47	0.47	0.18	0.12	0.03

1972	0.26	0.16	0.05	0.02	0.01	0.00

1973	11.46	7.26	2.92	1.17	0.78	0.19

1974	8.43	5.51	2.48	0.89	0.59	0.15

1975	121.00	76.50	25.17	8.89	5.93	1.46

1976	3.40	2.24	0.75	0.32	0.21	0.05

1977	22.84	14.90	4.64	1.64	1.09	0.27

1978	4.36	2.97	1.33	0.48	0.32	0.08

1979	25.22	17.99	6.45	2.32	1.55	0.38

1980	13.58	8.50	2.53	0.92	0.62	0.15

1981	48.17	35.30	10.74	3.82	2.55	0.63

1982	11.79	7.67	3.13	1.11	0.74	0.18

1983	69.12	43.79	14.74	5.25	3.50	0.86

1984	58.55	39.74	14.51	5.12	3.41	0.84

1985	74.81	50.89	19.38	6.88	4.59	1.13

1986	4.20	2.54	0.72	0.27	0.18	0.04

1987	35.62	22.02	9.68	3.51	2.34	0.58

1988	1.05	0.65	0.19	0.07	0.04	0.01

1989	39.87	23.74	7.03	2.52	1.68	0.41

1990	163.00	100.00	30.41	10.72	7.15	1.76

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	163.00	100.00	30.41	10.72	7.15	1.76

0.06	121.00	76.50	25.17	8.89	5.93	1.46

0.10	79.16	55.20	19.38	6.88	4.59	1.13

0.13	74.81	50.89	18.29	6.46	4.31	1.06

0.16	69.12	43.79	17.30	6.44	4.30	1.06

0.19	65.51	41.73	14.74	5.25	3.50	0.86

0.23	58.55	39.74	14.51	5.17	3.44	0.85

0.26	48.17	35.30	14.15	5.12	3.41	0.84

0.29	42.58	34.00	13.60	4.96	3.31	0.81

0.32	41.72	29.91	11.46	4.18	2.79	0.69

0.35	39.87	23.74	10.82	3.98	2.65	0.65

0.39	35.62	22.02	10.74	3.82	2.55	0.63

0.42	33.45	21.04	9.68	3.51	2.34	0.58

0.45	26.19	19.20	7.03	2.52	1.68	0.41

0.48	25.22	17.99	6.45	2.32	1.55	0.38

0.52	22.84	14.90	5.61	2.09	1.39	0.34

0.55	19.91	13.50	4.77	1.71	1.14	0.28

0.58	18.22	11.15	4.64	1.64	1.09	0.27

0.61	13.58	8.50	3.13	1.17	0.78	0.19

0.65	11.79	7.67	2.92	1.11	0.74	0.18

0.68	11.46	7.26	2.53	0.92	0.62	0.15

0.71	8.43	5.51	2.48	0.89	0.59	0.15

0.74	6.58	3.75	1.67	0.79	0.53	0.13

0.77	4.36	2.97	1.33	0.48	0.32	0.08

0.81	4.20	2.54	0.81	0.32	0.21	0.05

0.84	3.40	2.24	0.75	0.31	0.21	0.05

0.87	2.80	1.74	0.72	0.27	0.18	0.04

0.90	2.34	1.47	0.47	0.18	0.12	0.03

0.94	1.05	0.65	0.19	0.07	0.04	0.01

0.97	0.26	0.16	0.05	0.02	0.01	0.00

0.10	78.73	54.77	19.27	6.84	4.56	1.12

	Average of yearly averages:	0.50

Inputs generated by pe5.pl - Novemeber 2006

	Data used for this run:

Output File: FLTomato

	Metfile:	w12844.dvf

	PRZM scenario:	FLtomatoSTD.txt

EXAMS environment file:	pond298.exv

Chemical Name:	Chloropicrin

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	392	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-09	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.2.1 California Tomato

stored as CA_Tomto.out

	Chemical: Chloropicrin

	PRZM environment: CAtomato_WirrigSTD.txt	modified Tueday, 29 May 2007
at 12:43:54

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

	Metfile: w93193.dvf	modified Wedday, 3 July 2002 at 10:04:24

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	3.38E-05	2.67E-05	1.45E-05	5.87E-06	3.92E-06	9.65E-07

1962	3.38E-05	2.48E-05	9.78E-06	3.59E-06	2.39E-06	6.11E-07

1963	8.78E-05	6.88E-05	3.25E-05	2.14E-05	1.45E-05	3.57E-06

1964	0.000149	0.000108	4.65E-05	1.75E-05	1.17E-05	2.88E-06

1965	1.37E-05	1.10E-05	6.02E-06	3.16E-06	2.18E-06	5.39E-07

1966	4.23E-06	3.65E-06	2.16E-06	1.49E-06	9.93E-07	2.48E-07

1967	2.97E-05	2.33E-05	1.08E-05	4.21E-06	2.81E-06	6.98E-07

1968	0.00021	0.000158	6.76E-05	3.15E-05	2.11E-05	5.20E-06

1969	1.58E-05	1.34E-05	6.61E-06	2.58E-06	1.72E-06	4.26E-07

1970	1.97E-05	1.52E-05	9.08E-06	3.52E-06	2.35E-06	5.84E-07

1971	4.55E-06	3.58E-06	1.61E-06	7.50E-07	5.00E-07	1.32E-07

1972	0.000106	8.68E-05	5.60E-05	2.24E-05	1.50E-05	3.69E-06

1973	9.66E-05	7.24E-05	2.89E-05	1.11E-05	7.46E-06	1.85E-06

1974	0.001474	0.001082	0.000469	0.000179	0.00012	2.95E-05

1975	0.000259	0.000197	9.24E-05	3.58E-05	2.39E-05	5.93E-06

1976	0.000263	0.000198	7.95E-05	3.00E-05	2.01E-05	4.95E-06

1977	5.27E-06	4.11E-06	1.69E-06	5.91E-07	3.94E-07	9.86E-08

1978	2.16E-06	1.70E-06	8.23E-07	3.76E-07	2.51E-07	7.85E-08

1979	1.17E-05	9.21E-06	4.13E-06	1.58E-06	1.06E-06	2.62E-07

1980	8.82E-07	7.16E-07	3.47E-07	1.29E-07	8.62E-08	2.32E-08

1981	2.26E-05	1.67E-05	7.26E-06	2.90E-06	1.94E-06	4.79E-07

1982	0.000861	0.000627	0.000364	0.000152	0.000105	2.59E-05

1983	6.06E-05	4.15E-05	1.65E-05	9.48E-06	6.64E-06	1.65E-06

1984	2.01E-05	1.49E-05	7.73E-06	5.11E-06	3.58E-06	8.81E-07

1985	0.000204	0.000152	6.42E-05	3.19E-05	2.13E-05	5.27E-06

1986	9.76E-07	7.86E-07	4.25E-07	1.85E-07	1.23E-07	3.84E-08

1987	1.95E-05	1.42E-05	6.19E-06	2.61E-06	1.74E-06	4.38E-07

1988	8.79E-06	7.33E-06	3.67E-06	1.51E-06	1.01E-06	2.49E-07

1989	8.62E-06	5.90E-06	2.00E-06	7.18E-07	7.69E-07	2.03E-07

1990	1.93E-06	1.55E-06	8.03E-07	3.66E-07	2.44E-07	6.58E-08

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	0.00	0.00	0.00	0.00	0.00	0.00

0.06	0.00	0.00	0.00	0.00	0.00	0.00

0.10	0.00	0.00	0.00	0.00	0.00	0.00

0.13	0.00	0.00	0.00	0.00	0.00	0.00

0.16	0.00	0.00	0.00	0.00	0.00	0.00

0.19	0.00	0.00	0.00	0.00	0.00	0.00

0.23	0.00	0.00	0.00	0.00	0.00	0.00

0.26	0.00	0.00	0.00	0.00	0.00	0.00

0.29	0.00	0.00	0.00	0.00	0.00	0.00

0.32	0.00	0.00	0.00	0.00	0.00	0.00

0.35	0.00	0.00	0.00	0.00	0.00	0.00

0.39	0.00	0.00	0.00	0.00	0.00	0.00

0.42	0.00	0.00	0.00	0.00	0.00	0.00

0.45	0.00	0.00	0.00	0.00	0.00	0.00

0.48	0.00	0.00	0.00	0.00	0.00	0.00

0.52	0.00	0.00	0.00	0.00	0.00	0.00

0.55	0.00	0.00	0.00	0.00	0.00	0.00

0.58	0.00	0.00	0.00	0.00	0.00	0.00

0.61	0.00	0.00	0.00	0.00	0.00	0.00

0.65	0.00	0.00	0.00	0.00	0.00	0.00

0.68	0.00	0.00	0.00	0.00	0.00	0.00

0.71	0.00	0.00	0.00	0.00	0.00	0.00

0.74	0.00	0.00	0.00	0.00	0.00	0.00

0.77	0.00	0.00	0.00	0.00	0.00	0.00

0.81	0.00	0.00	0.00	0.00	0.00	0.00

0.84	0.00	0.00	0.00	0.00	0.00	0.00

0.87	0.00	0.00	0.00	0.00	0.00	0.00

0.90	0.00	0.00	0.00	0.00	0.00	0.00

0.94	0.00	0.00	0.00	0.00	0.00	0.00

0.97	0.00	0.00	0.00	0.00	0.00	0.00

0.10	0.00	0.00	0.00	0.00	0.00	0.00

	Average of yearly averages:	3.25E-06

Inputs generated by pe5.pl - Novemeber 2006

	Data used for this run:

	Output File: CA_Tomto

	Metfile:	w93193.dvf

	PRZM scenario:	CAtomato_WirrigSTD.txt

	EXAMS environment file:	pond298.exv

Chemical Name:	Chloropicrin

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	392	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-09	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.2.2 California Onion

stored as CA_Onion.out

	Chemical: Chloropicrin

	PRZM environment: CAonion_WirrigSTD.txt	modified Tueday, 29 May 2007 at
12:43:34

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

	Metfile: w23155.dvf	modified Wedday, 3 July 2002 at 10:04:20

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	6.59E-05	5.05E-05	3.16E-05	1.30E-05	8.67E-06	2.14E-06

1962	1.30E-06	1.03E-06	4.78E-07	1.83E-07	1.22E-07	3.01E-08

1963	6.329	4.349	1.488	0.5364	0.3577	0.08819

1964	0.004439	0.003098	0.001246	0.000459	0.000306	7.53E-05

1965	0.000296	0.000221	9.25E-05	3.48E-05	2.32E-05	5.75E-06

1966	0.000705	0.000552	0.000231	9.65E-05	6.43E-05	1.59E-05

1967	0.000437	0.000378	0.000188	7.49E-05	4.99E-05	1.24E-05

1968	0.05576	0.04223	0.01795	0.007004	0.004679	0.001151

1969	0.000426	0.000318	0.000127	4.62E-05	3.08E-05	7.97E-06

1970	0.000199	0.000145	6.64E-05	2.46E-05	1.64E-05	4.05E-06

1971	1.55E-06	1.32E-06	6.20E-07	2.36E-07	1.58E-07	5.77E-08

1972	0.01245	0.008742	0.003131	0.00137	0.000915	0.000225

1973	2.85E-05	2.27E-05	1.05E-05	3.98E-06	2.65E-06	7.22E-07

1974	1.709	1.211	0.4316	0.1551	0.1034	0.02551

1975	6.93E-06	5.53E-06	2.57E-06	9.78E-07	6.52E-07	1.61E-07

1976	0.1784	0.1172	0.0398	0.01416	0.009438	0.002321

1977	5.07E-06	3.72E-06	8.83E-07	3.09E-07	2.06E-07	7.76E-08

1978	2.63E-06	1.99E-06	8.15E-07	3.04E-07	2.03E-07	9.19E-08

1979	4.20E-07	3.23E-07	1.81E-07	7.34E-08	4.90E-08	1.21E-08

1980	2.73E-07	2.25E-07	1.19E-07	4.57E-08	3.05E-08	7.49E-09

1981	0.5819	0.4225	0.1579	0.05689	0.03793	0.009352

1982	1.098	0.7351	0.2513	0.09028	0.06023	0.01485

1983	0.000473	0.000363	0.000224	9.95E-05	6.64E-05	1.66E-05

1984	0.000198	0.000153	6.93E-05	2.73E-05	1.82E-05	4.61E-06

1985	0.002638	0.002044	0.000887	0.000339	0.000226	5.58E-05

1986	0.000119	9.13E-05	3.92E-05	1.57E-05	1.05E-05	2.75E-06

1987	0.02061	0.01593	0.006823	0.002529	0.001686	0.000416

1988	4.71E-06	3.28E-06	1.14E-06	4.05E-07	2.70E-07	7.39E-08

1989	0.2818	0.1656	0.04519	0.01586	0.01057	0.002607

1990	5.56E-06	3.91E-06	1.45E-06	5.28E-07	3.52E-07	8.67E-08

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	6.329	4.349	1.488	0.5364	0.3577	0.08819

0.06	1.709	1.211	0.4316	0.1551	0.1034	0.02551

0.10	1.098	0.7351	0.2513	0.09028	0.06023	0.01485

0.13	0.5819	0.4225	0.1579	0.05689	0.03793	0.009352

0.16	0.2818	0.1656	0.04519	0.01586	0.01057	0.002607

0.19	0.1784	0.1172	0.0398	0.01416	0.009438	0.002321

0.23	0.05576	0.04223	0.01795	0.007004	0.004679	0.001151

0.26	0.02061	0.01593	0.006823	0.002529	0.001686	0.000416

0.29	0.01245	0.008742	0.003131	0.00137	0.000915	0.000225

0.32	0.004439	0.003098	0.001246	0.000459	0.000306	7.53E-05

0.35	0.002638	0.002044	0.000887	0.000339	0.000226	5.58E-05

0.39	0.000705	0.000552	0.000231	9.95E-05	6.64E-05	1.66E-05

0.42	0.000473	0.000378	0.000224	9.65E-05	6.43E-05	1.59E-05

0.45	0.000437	0.000363	0.000188	7.49E-05	4.99E-05	1.24E-05

0.48	0.000426	0.000318	0.000127	4.62E-05	3.08E-05	7.97E-06

0.52	0.000296	0.000221	9.25E-05	3.48E-05	2.32E-05	5.75E-06

0.55	0.000199	0.000153	6.93E-05	2.73E-05	1.82E-05	4.61E-06

0.58	0.000198	0.000145	6.64E-05	2.46E-05	1.64E-05	4.05E-06

0.61	0.000119	9.13E-05	3.92E-05	1.57E-05	1.05E-05	2.75E-06

0.65	6.59E-05	5.05E-05	3.16E-05	1.30E-05	8.67E-06	2.14E-06

0.68	2.85E-05	2.27E-05	1.05E-05	3.98E-06	2.65E-06	7.22E-07

0.71	6.93E-06	5.53E-06	2.57E-06	9.78E-07	6.52E-07	1.61E-07

0.74	5.56E-06	3.91E-06	1.45E-06	5.28E-07	3.52E-07	9.19E-08

0.77	5.07E-06	3.72E-06	1.14E-06	4.05E-07	2.70E-07	8.67E-08

0.81	4.71E-06	3.28E-06	8.83E-07	3.09E-07	2.06E-07	7.76E-08

0.84	2.63E-06	1.99E-06	8.15E-07	3.04E-07	2.03E-07	7.39E-08

0.87	1.55E-06	1.32E-06	6.20E-07	2.36E-07	1.58E-07	5.77E-08

0.90	1.30E-06	1.03E-06	4.78E-07	1.83E-07	1.22E-07	3.01E-08

0.94	4.20E-07	3.23E-07	1.81E-07	7.34E-08	4.90E-08	1.21E-08

0.97	2.73E-07	2.25E-07	1.19E-07	4.57E-08	3.05E-08	7.49E-09

0.10	1.05	0.70	0.24	0.09	0.06	0.01

	Average of yearly averages:	0.00

Inputs generated by pe5.pl - Novemeber 2006

	Data used for this run:

Output File: CA_Onion

	Metfile:	w23155.dvf

	PRZM scenario:	CAonion_WirrigSTD.txt

	EXAMS environment file:	pond298.exv

Chemical Name:	Chloropicrin

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	392	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-09	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.3.1 North Carolina Tobacco

stored as NC_Tobco.out

	Chemical: Chloropicrin

	PRZM environment: NCtobaccoSTD.txt	modified Tueday, 29 May 2007 at
12:59:12

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

Metfile: w13722.dvf	modified Wedday, 3 July 2002 at 10:05:50

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.09	0.07	0.02	0.01	0.01	0.00

1962	0.00	0.00	0.00	0.00	0.00	0.00

1963	0.16	0.12	0.04	0.02	0.01	0.00

1964	0.00	0.00	0.00	0.00	0.00	0.00

1965	0.01	0.01	0.00	0.00	0.00	0.00

1966	0.37	0.27	0.09	0.04	0.02	0.01

1967	0.78	0.54	0.24	0.09	0.06	0.01

1968	0.00	0.00	0.00	0.00	0.00	0.00

1969	0.01	0.01	0.00	0.00	0.00	0.00

1970	0.06	0.04	0.01	0.01	0.00	0.00

1971	0.01	0.01	0.00	0.00	0.00	0.00

1972	0.14	0.10	0.04	0.01	0.01	0.00

1973	0.71	0.52	0.18	0.06	0.04	0.01

1974	0.05	0.04	0.02	0.01	0.01	0.00

1975	0.03	0.02	0.01	0.00	0.00	0.00

1976	0.02	0.01	0.01	0.00	0.00	0.00

1977	0.02	0.01	0.00	0.00	0.00	0.00

1978	1.21	0.87	0.33	0.12	0.08	0.02

1979	0.03	0.02	0.01	0.00	0.00	0.00

1980	0.07	0.05	0.02	0.01	0.00	0.00

1981	0.02	0.01	0.00	0.00	0.00	0.00

1982	0.31	0.22	0.08	0.03	0.02	0.01

1983	0.00	0.00	0.00	0.00	0.00	0.00

1984	0.43	0.35	0.13	0.05	0.03	0.01

1985	0.29	0.21	0.07	0.03	0.02	0.00

1986	0.02	0.02	0.01	0.00	0.00	0.00

1987	0.01	0.01	0.00	0.00	0.00	0.00

1988	1.20	0.87	0.32	0.12	0.08	0.02

1989	0.56	0.39	0.14	0.05	0.03	0.01

1990	0.18	0.12	0.04	0.02	0.01	0.00

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	1.21	0.87	0.33	0.12	0.08	0.02

0.06	1.20	0.87	0.32	0.12	0.08	0.02

0.10	0.78	0.54	0.24	0.09	0.06	0.01

0.13	0.71	0.52	0.18	0.06	0.04	0.01

0.16	0.56	0.39	0.14	0.05	0.03	0.01

0.19	0.43	0.35	0.13	0.05	0.03	0.01

0.23	0.37	0.27	0.09	0.04	0.02	0.01

0.26	0.31	0.22	0.08	0.03	0.02	0.01

0.29	0.29	0.21	0.07	0.03	0.02	0.00

0.32	0.18	0.12	0.04	0.02	0.01	0.00

0.35	0.16	0.12	0.04	0.02	0.01	0.00

0.39	0.14	0.10	0.04	0.01	0.01	0.00

0.42	0.09	0.07	0.02	0.01	0.01	0.00

0.45	0.07	0.05	0.02	0.01	0.01	0.00

0.48	0.06	0.04	0.02	0.01	0.00	0.00

0.52	0.05	0.04	0.01	0.01	0.00	0.00

0.55	0.03	0.02	0.01	0.00	0.00	0.00

0.58	0.03	0.02	0.01	0.00	0.00	0.00

0.61	0.02	0.02	0.01	0.00	0.00	0.00

0.65	0.02	0.01	0.01	0.00	0.00	0.00

0.68	0.02	0.01	0.00	0.00	0.00	0.00

0.71	0.02	0.01	0.00	0.00	0.00	0.00

0.74	0.01	0.01	0.00	0.00	0.00	0.00

0.77	0.01	0.01	0.00	0.00	0.00	0.00

0.81	0.01	0.01	0.00	0.00	0.00	0.00

0.84	0.01	0.01	0.00	0.00	0.00	0.00

0.87	0.00	0.00	0.00	0.00	0.00	0.00

0.90	0.00	0.00	0.00	0.00	0.00	0.00

0.94	0.00	0.00	0.00	0.00	0.00	0.00

0.97	0.00	0.00	0.00	0.00	0.00	0.00

0.10	0.78	0.54	0.24	0.09	0.06	0.01

	Average of yearly averages:	0.00

Inputs generated by pe5.pl - Novemeber 2006

Data used for this run:

Output File: NC_Tobco

	Metfile:	w13722.dvf

	PRZM scenario:	NCtobaccoSTD.txt

EXAMS environment file:	pond298.exv

	Chemical Name:	Chloropicrin

	Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

	Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	392	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-04	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.3.2 North Carolina Sweet Potato

stored as NC_Potato.out

	Chemical: Chloropicrin

	PRZM environment: NCSweetPotatoSTD.txt	modified Tueday, 29 May 2007 at
12:58:56

EXAMS environment: pond298.exv	modified Thuday, 29 August 2002 at
16:33:30

	Metfile: w13722.dvf	modified Wedday, 3 July 2002 at 10:05:50

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.18	0.13	0.05	0.02	0.01	0.00

1962	0.03	0.02	0.01	0.00	0.00	0.00

1963	0.05	0.04	0.01	0.01	0.01	0.00

1964	0.00	0.00	0.00	0.00	0.00	0.00

1965	0.09	0.07	0.02	0.01	0.01	0.00

1966	0.75	0.55	0.22	0.08	0.05	0.01

1967	0.67	0.47	0.24	0.09	0.06	0.02

1968	0.06	0.04	0.02	0.01	0.01	0.00

1969	0.09	0.07	0.02	0.01	0.01	0.00

1970	0.17	0.12	0.04	0.01	0.01	0.00

1971	0.15	0.11	0.04	0.02	0.01	0.00

1972	0.33	0.23	0.11	0.04	0.03	0.01

1973	1.29	0.94	0.34	0.12	0.08	0.02

1974	0.18	0.13	0.07	0.03	0.02	0.00

1975	0.01	0.01	0.00	0.00	0.00	0.00

1976	0.07	0.05	0.02	0.01	0.01	0.00

1977	0.04	0.03	0.01	0.00	0.00	0.00

1978	3.23	2.32	0.89	0.33	0.22	0.05

1979	0.10	0.07	0.04	0.02	0.01	0.00

1980	0.04	0.03	0.01	0.00	0.00	0.00

1981	0.03	0.02	0.01	0.00	0.00	0.00

1982	0.77	0.55	0.21	0.08	0.06	0.01

1983	0.01	0.01	0.00	0.00	0.00	0.00

1984	0.79	0.61	0.24	0.09	0.06	0.01

1985	0.49	0.35	0.12	0.05	0.03	0.01

1986	0.09	0.06	0.02	0.01	0.01	0.00

1987	0.05	0.03	0.02	0.01	0.00	0.00

1988	0.86	0.62	0.23	0.08	0.06	0.01

1989	0.80	0.59	0.25	0.09	0.06	0.01

1990	0.50	0.35	0.14	0.05	0.03	0.01

Sorted results

Prob.	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

0.03	3.23	2.32	0.89	0.33	0.22	0.05

0.06	1.29	0.94	0.34	0.12	0.08	0.02

0.10	0.86	0.62	0.25	0.09	0.06	0.02

0.13	0.80	0.61	0.24	0.09	0.06	0.01

0.16	0.79	0.59	0.24	0.09	0.06	0.01

0.19	0.77	0.55	0.23	0.08	0.06	0.01

0.23	0.75	0.55	0.22	0.08	0.06	0.01

0.26	0.67	0.47	0.21	0.08	0.05	0.01

0.29	0.50	0.35	0.14	0.05	0.03	0.01

0.32	0.49	0.35	0.12	0.05	0.03	0.01

0.35	0.33	0.23	0.11	0.04	0.03	0.01

0.39	0.18	0.13	0.07	0.03	0.02	0.00

0.42	0.18	0.13	0.05	0.02	0.01	0.00

0.45	0.17	0.12	0.04	0.02	0.01	0.00

0.48	0.15	0.11	0.04	0.02	0.01	0.00

0.52	0.10	0.07	0.04	0.01	0.01	0.00

0.55	0.09	0.07	0.02	0.01	0.01	0.00

0.58	0.09	0.07	0.02	0.01	0.01	0.00

0.61	0.09	0.06	0.02	0.01	0.01	0.00

0.65	0.07	0.05	0.02	0.01	0.01	0.00

0.68	0.06	0.04	0.02	0.01	0.01	0.00

0.71	0.05	0.04	0.02	0.01	0.01	0.00

0.74	0.05	0.03	0.01	0.01	0.00	0.00

0.77	0.04	0.03	0.01	0.00	0.00	0.00

0.81	0.04	0.03	0.01	0.00	0.00	0.00

0.84	0.03	0.02	0.01	0.00	0.00	0.00

0.87	0.03	0.02	0.01	0.00	0.00	0.00

0.90	0.01	0.01	0.00	0.00	0.00	0.00

0.94	0.01	0.01	0.00	0.00	0.00	0.00

0.97	0.00	0.00	0.00	0.00	0.00	0.00

0.10	0.85	0.62	0.25	0.09	0.06	0.02

	Average of yearly averages:	0.01

Inputs generated by pe5.pl - Novemeber 2006

	Data used for this run:

Output File: NC_Potato

	Metfile:	w13722.dvf

	PRZM scenario:	NCSweetPotatoSTD.txt

	EXAMS environment file:	pond298.exv

Chemical Name:	Chloropicrin

Description	Variable Name	Value	Units	Comments

Molecular weight	mwt	164.4	g/mol

	Henry's Law Const.	henry	0.00205	atm-m^3/mol

Vapor Pressure	vapr	23.8	torr

	Solubility	sol	1621	mg/L

	Kd	Kd

mg/L

	Koc	Koc	36.05	mg/L

	Photolysis half-life	kdp	1.3	days	Half-life

Aerobic Aquatic Metabolism	kbacw	10.66	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.09	days	Halfife

Aerobic Soil Metabolism	asm	5.33	days	Halfife

Hydrolysis:	pH 7	0	days	Half-life

Method:	CAM	8	integer	See PRZM manual

	Incorporation Depth:	DEPI	25	cm

	Application Rate:	TAPP	392	kg/ha

	Application Efficiency:	APPEFF	1	fraction

	Spray Drift	DRFT	0	fraction of application rate applied to pond

Application Date	Date	15-04	dd/mm or dd/mmm or dd-mm or dd-mmm

Record 17:	FILTRA

IPSCND	1

	UPTKF

	Record 18:	PLVKRT

PLDKRT

FEXTRC	0

Flag for Index Res. Run	IR	EPA Pond

Flag for runoff calc.	RUNOFF	none	none, monthly or total(average of
entire run)

B.4.   Calculation of 1-in-10 year EEC using Weibull Probability Plots.

Output from the PRZM/EXAMS simulation is typically a series of estimated
environmental concentrations (EEC) corresponding to multiple years of
meteorological data.  Each value is an estimate of the peak
concentrations corresponding to a specific averaging time (e.g., 96
hours, 21 days, etc.).  The 24-hour averaging time is sometimes referred
to as the “Peak” concentration because the shortest time-step for a
PRZM/EXAMS simulations is one day.  Therefore, the column of EEC values
reported in an output file for “Peak” refers to the maximum 24-hour
EEC for each of the meteorological years.

For ecological risk assessment, it is important to match the averaging
time to the duration of the toxicity study.  However, of the multiple
years of data, which EEC should be selected in the calculation of the
RQ?  The most conservative case would be to choose the maximum EEC for
each averaging time.  An alternative would be to calculate an upper end
value that is less than the maximum.  One statistic adopted by OPP for
use in ecological risk assessment is the 1-in-10 year return value. 
This is the EEC that, on average, will be exceeded only once every 10
years.  It is important to note that for any single 10-year period, the
1-in-10 year value may be exceeded more than once, or not at all.  The
key concept is that it represents the average probability of exceedance.

		

The 1-in-10 year statistic can be calculated using probability plotting
methods.  There are a number of different techniques, but a common
practice in hydrology for plotting flow-duration and flood-frequency
curves is to use the plotting position associated with the Weibull
distribution (Helsel and Hirsch 1993).  The general formula for
probability plotting is given by:

 

	

where p is the probability level, n is the number of data points, and a
is a coefficient that varies between 0 and 0.5.  For the Weibull
distribution, a is 0 so the plotting position is

 

				

For the PRZM/EXAMS simulations presented above, there are 30 years of
meteorological data, so n = 30.  To generate a Weibull probability plot
to estimate the exceedance probabilities, the data should be sorted in
descending order.  That is, there is a lower probability of exceeding
the maximum EEC than the second highest EEC.  The plotting position
associated with the maximum value is then calculated as follows:

 

The minimum and maximum probability values associated with the entire
data set will approach [0, 1] as the sample size increases.  Sometimes
probability plots are used to estimate the values beyond the observed
range.  To calculate the 1-in-10 year statistic, we need the EEC
associated with a probability value of 0.100.  This value does not
correspond directly with any of the modeled values, but it is between
third highest value (p = 0.097) and fourth highest value (0.129).  An
interpolation procedure is needed to estimate the EEC associated with p
= 0.100.  A linear interpolation is commonly performed, although two
methods are available.  One method involves fitting a line to the entire
set of data plotted on a Weibull probability plot.  The second method
involves a linear interpolation only between the two values that
encompass the desired p-value.  PRZM/EXAMS output is based on the
Weibull plotting positions with a straight line interpolation between
just the two data values that encompass the desired p-value of 0.100. 

 

	Appendix C:  Ecological Effects Data  TC "Appendix C:  Ecological
Effects Data" \f C \l "2"  

Overview

	The toxicity testing required does not test all species of birds, fish,
mammals, invertebrates, and plants.  Only two surrogate species for
birds (bobwhite quail and mallard) are used to represent all bird
species (over 1000 in the US, including subspecies),  three species of
freshwater fish (rainbow trout, bluegill sunfish and fathead minnow) are
used to represent all freshwater fish species (over 900 in the US), and
one estuarine/marine fish species (sheepshead minnow) is used to
represent all estuarine/marine fish (over 300 in the US).  The surrogate
species for terrestrial invertebrates is the honey bee, for freshwater
invertebrates the surrogate species is usually the waterflea (Daphnia
magna) and for estuarine/marine invertebrates the surrogate species are
mysid shrimp and eastern oyster.  These four species are used to
represent all invertebrate species (over 10,000 in the US).  For plants,
there are ten surrogate species used for all terrestrial plants and five
surrogate species used for all aquatic plants.  There are over 20,000
plant species in the US which includes flowering plants, conifers,
ferns, mosses, liverworts, hornworts and lichens with over 27,000
species of algae worldwide.

	The surrogate species testing scheme used in this assessment assumes
that a chemical’s mechanism of action and toxicity found for avian
species is similar to that in all reptiles (over 300 species in the US).
 The same assumption applies to amphibians (over 200 species in the US)
and fish; the tadpole stage of amphibians is assumed to have the same
sensitivity as a fish.  Therefore, the results from toxicity tests on
surrogate species are considered applicable to other member species
within their class and are extrapolated to reptiles and amphibians.  The
US species numbers noted in this section were taken from the Natureserve
website (   HYPERLINK http://www.natureserve.org www.natureserve.org 
NatureServe: An online encyclopedia of life [web application].2000) and
the worldwide species number from Ecological Planning and Toxicology,
Inc.1996.

	In the following sections, the shaded values in the tables are the ones
used in the current risk assessment.

a.  Toxicity to Terrestrial Animals

	  i.  Birds, Acute and Subacute

An acute oral toxicity study using the technical grade of the active
ingredient (TGAI) is required to establish the toxicity of chloropicrin
to birds.  The avian oral LD50 is an acute, single-dose laboratory study
designed to estimate the quantity of toxicant required to cause 50%
mortality in a test population of birds.  The preferred test species is
either the mallard, a waterfowl, or bobwhite quail, an upland gamebird. 
The TGAI is administered by oral intubation to adult birds, and the
results are expressed as LD50 milligrams (mg) active ingredient (a.i.)
per kilogram (kg) of body weight.  Toxicity category descriptions are
the following:

 	If the LD50 is less than 10 mg a.i./kg, then the test substance is
very highly toxic.

If the LD50 is 10-to-50 mg a.i./kg, then the test substance is highly
toxic.

If the LD50 is 51-to-500 mg a.i./kg, then the test substance is
moderately toxic.

If the LD50 is 501-to-2,000 mg a.i./kg, then the test substance is
slightly toxic.

If the LD50 is greater than 2,000 mg a.i./kg, then the test substance is
practically nontoxic.

Acute oral testing on chloropicrin is needed for risk assessment. 

Two dietary studies using the TGAI are usually required to establish the
toxicity of pesticides to birds.  These avian dietary LC50 tests, using
the mallard and bobwhite quail, are acute, eight-day dietary laboratory
studies designed to estimate the quantities of toxicant in the feed
required to cause 50% mortality in the two respective test populations
of birds.  The TGAI is administered by mixture to juvenile birds' diets
for five days followed by three days of "clean" diet, and the results
are expressed as LC50 parts per million (ppm) active ingredient (a.i.)
in the diet.  Toxicity category descriptions are the following:  

If the LC50 is less than 50 ppm a.i., then the test substance is very
highly toxic.

If the LC50 is 50-to-500 ppm a.i., then the test substance is highly
toxic.

If the LC50 is 501-to-1,000 ppm a.i., then the test substance is
moderately toxic.

If the LC50 is 1001-to-5,000 ppm a.i., then the test substance is
slightly toxic.

If the LC50 is greater than 5,000 ppm a.i., then the test substance is
practically nontoxic.

 However, dietary exposure is not considered to be the primary or even a
substantial route of avian exposure to chloropicrin, and thus avian
dietary toxicity data are not currently needed for risk assessment. 
Inhalation is expected to be the primary route of exposure and thus
acute inhalation toxicity data on chloropicrin are needed for risk
assessment.  

	ii.  Birds, Chronic

Chronic/sub-chronic inhalation testing with chloropicrin is needed to
assess risk to birds in part because of the potential for repeated or
continuous exposure resulting from multiple fields being treated on
differing days within a given geographic area.

	iii.  Mammalian Toxicity Data (from HED	

 Chloropicrin Toxicity Profile (from HED 1/31/05 review)

Guideline No./Study Type	MRID No. (year)/Classification/Exposure
Conditions	Results

870.1100  

Acute Oral - Rat

	05014376 (1976)

Acceptable/Guideline.

	LD50 = 37.5 mg/kg

Toxicity Category I

870.1200

Acute Dermal - Rat

	05014376 (1976)

Acceptable/Guideline

	LD50 = 100 mg/kg

Toxicity Category I

870.1300

Acute Inhalation - Mouse

	45117901 (1999)

Acceptable/Non-Guideline

Head only study, 4 Albino Swiss-Webster male mice/grp exposed to 0.99,
3.20, 4.20, 7.25, 10.00, 14.50 ppm (analytical concen.)or 0.00664,
0.0215, 0.0282, 0.0486, 0.0671, 0.0973 mg/L (calculated analytical
concen.)of gaseous CP for 30 mins.	No deaths seen at any dose level.
Clinical obs. normal before and after exposure. Body wt. gains may been
decreased at HDT only (8% of initial body wt. in control and 2% at the
HDT).

-The exposure level at 50% RD (RD50) was 2.34 ppm with 95% CI of 1.84 to
2.98 ppm or RD50 of 0.016 mg/L and 95% CI of 0.012 mg/L to 0.020 mg/L.

-0% depression in the respiration rate was plotted by the % depression
in the respiration rate reported in the study versus log exposure level
and extrapolating the graph to 0% depression. The RD0 respiratory
depression occurs around 0.0017 to 0.0019 mg/L.

870.1300

Acute Inhalation - Rat	45117902 (1999)

Acceptable/Non-Guideline

Whole body inhalation study, 5 Sprague Dawley rats/sex/grp were exposed
to 0, 10.6, 18.0, or 28.5 ppm (analytical) or 0, 0.071, 0.121, 0.158
mg/L (calculated) of aerosolized CP for 4-hrs and held for 2 days after
exposure. Particle sizes had a MMAD from 4.85 µm to 6.1µm with a GDS
of 1.4 to 1.6. 	LC50 [typo corrected] was 17 ppm (M) and 19 ppm (F).

Death only occurred at 2 top dose levels up to 2 days post-exposure. 

Clinical signs: obs noted at all dose levels, labored breathing,
gasping, decreased activity, nasal discharge, salivation, moist rales.
Top 2 levels produced gasping for last 2 hrs of exposure.

Gross pathology: Liver, adrenal wts, and histological findings increased
at HDT. Histological findings of respiratory tract were seen at all dose
levels and damage to the lungs, such as congestion, bronchiole mucosal
edema, necrosis, and cellular infiltrates.

-No NOAEL demonstrated.

LOAEL = 10.6 ppm or 0.071 mg/L (LDT).

870.2400C

Primary Eye Irritation - Rabbit

	N/A

	reserved

870.2500

Primary Skin Irritation - Rabbit

	05014376 (1976)

 Acceptable/Guideline

	Corrosive

Toxicity Category I

870.2600

Dermal Sensitization 	N/A

	Reserved

870.3100

Subchronic Feeding - Rat

Not required by the Agency

870.3100

Subchronic Feeding - Mice 

Not required by the Agency

870.3100

Subchronic Feeding - Mice

Not required by the Agency

870.3150

Subchronic Feeding - Dog

Not required by the Agency

870.3200

21-Day Dermal - Rat

Reserved

870.3465

13-Week Inhalation - Mouse

	43063201 (1993)

Acceptable/Guideline 

0, 0.3, 1.0, or3.0 ppm in a whole-body chamber, 6 h/day, 5 days/week for
13 weeks	NOAEL = 0.3 ppm (0.002 mg/L/day)

LOAEL = 1.0 ppm (0.007 mg/L/day) based on decreased body weight and food
consumption, increased absolute and relative lung weights in both sexes,
and histopathological lesions of the nasal cavity and lungs of females.

870.3465

13-Week Inhalation - Rat	43063201 (1993)

Acceptable/Guideline 

0, 0.3, 1.0, or3.0 ppm in a whole-body chamber, 6 h/day, 5 days/week for
13 weeks	NOAEL = 0.3 ppm (0.002 mg/L/day)

LOAEL = 1.0 ppm (0.007 mg/L/day), based on increased lung weights of
both sexes, and histopathological changes in the nose of females and
lungs of males and females.

870.3700

Inhalation Developmental Toxicity - Rat

	42740602 (1993)

Acceptable/Guideline

0, 0.4, 1.2, or 3.5 ppm in a whole-body inhalation chamber, 6 h/day on
GDs 6-15.  	Maternal NOAEL = 0.4 ppm (0.003 mg/L/day)

Maternal LOAEL = 1.2 ppm (0.008 mg/L/day) based on mortality, decreased
body weight and food consumption, and signs consistent with CP toxicity.

Developmental NOAEL > 3.5 ppm (0.024 mg/L)

Developmental LOAEL= 3.5 ppm (0.024 mg/L), based on decreased pup body
weights.

870.3700

Inhalation Developmental Toxicity - Rabbit

	42740601 (1993)

Acceptable/Guideline

0, 0.4, 1.2, or 2.0 ppm in a whole-body inhalation chamber, 6 h/day, on
GDs 7-29.

	Maternal NOAEL is 0.4 ppm (0.003 mg/L)

Maternal LOAEL is 1.2 ppm (0.008 mg/L), based on mortality, body weight
loss, and decreased food consumption. 

Developmental NOAEL= 0.4 ppm (0.003 mg/L)

Developmental LOAEL= 1.2 ppm (0.008 mg/L), based on abortions and
decreased fetal weights.

870.3800

Inhalation 2-Generation Reproductive Toxicity - 

(Main study)

Rat	43391901 (1994)

Acceptable/guideline

0, 0.5, 1.0, or 1.5 ppm in whole body inhalation chamber 

Note: Offspring not directly exposed until PND 28	Parental systemic
NOAEL > 1.5 ppm (0.0101 mg/L)

Parental systemic LOAEL not identified

Offspring NOAEL > 1.5 ppm (0.0101 mg/L)

Offspring LOAEL not identified

Reproductive NOAEL > 1.5 ppm (0.0101 mg/L)

Reproductive LOAEL not identified

870.3800

Range-finding, Inhalation 2-Generation Reproductive Toxicity - Rat
46427801 (conducted 1992, study report 1996)

0, 0.4, 1.0, or 2.0 ppm whole body for 6hrs/day, 7 days/week during
premating (14 days) and gestation day 0-20.	No treatment-related
mortality, clinical signs, or necropsy findings in any parental males or
females, and no treatment-related effects on reproductive parameters.
Mean body weight and weight gain decreased in high-dose group (1-3% M&
5-6% F) beginning at week 1.  Maternal body weight was decreased 5-8%
and decreased 17% during gestation.  Food consumption decreased 8-14% in
males and 14% in females during premating and 7% during gestation. 
Litter size decreased 33% and uterine implantation sites decreased 30%
in the high-dose group.

870.4100

Chronic Feeding Toxicity-Rat	43744301 (1995)

Acceptable/guideline

Gavage at 0, 0.1, 1.0, or 10 mg/kg/day for 104 weeks.	Only clinical
toxicity observed was salivation after dosing in high-dose male and
female rats. Dose-related increase in incidence of subcutaneous masses
of skin of females related to the increased incidence of mammary
fibroadenomas. Hyper-keratosis and hyperplasia of the nonglandular
stomach in both sexes. Females had dose-related increase in incidence of
fibroadenoma of the mammary gland at high-dose. Increased rate of C-cell
hyperplasia of the thyroid in high-dose females.

NOAEL = 0.1 mg/kg/day [F]

NOAEL = 1.0 mg/kg/day [M]

LOAEL = 1.0 mg/kg/day [F], based on periportal hepatocyte vacuolation
and thyroid C-cell hyperplasia and stomach lesions at the high-dose.

LOAEL = 10 mg/kg/day [M], basedon on stomach lesions.

870.4100

Chronic Feeding Toxicity - Dog	43196301(1994)

Acceptable/guideline

0, 0.1, 1.0, or 5.0 mg/kg/day for one year (capsule).	NOAEL [M] = 0.1
mg/kg/day

NOAEL [F] = 1.0 mg/kg/day

LOAEL [M] = 1.0 mg/kg/day, based on gastrointestinal irritation
(vomiting and diarrhea), and blood chemistry alterations, 

LOAEL [F] = 5.0 mg/kg/day, based on gastrointestinal irritation
(vomiting and diarrhea), microcytic hypochromatic anemia, and blood
chemistry alterations.

870.4200

Carcinogenicity Inhalation - Mouse (78 weeks) 	43632201 (1997)

Acceptable/guideline

0, 0.1, 0.5, or 1.0 ppm for 78 weeks	NOAEL = 0.1 ppm (0.0007 mg/L)

LOAEL = 0.5 ppm (0.0034 mg/L), based on systemic toxicity and
irritation, based on decreased body weights and gains, increased lung
weights, and histological changes in the nasal cavity, upper respiratory
tract and lungs.

No significant treatment-related increase in tumors.

870.4200

Carcinogenicity/gavage- Mouse/Rat [bioassay]	05014915 (1978)

supplemental

Rats: [M]: 0, 25 or 26 mg/kg/day

[F]: 0, 20, or 22 mg/kg/day

Mice [M]: 0, 66 mg/kg/day

[F]: 0, 33 mg/kg/day	High-incidence of early death in CP dose rats. No
neoplasm observed at higher incidences in dosed rats from controls.
Rapid decrease in survival after first year in both sexes of mice.

Proliferative lesions of squamous epithelium of the forestomach of mice
included two carcinomas and a papilloma. Statistical analysis did not
demonstrate related to CP.  Bioassay of CP did not permit evaluation of
carcinogenicity due to short survival time of mice and rats.

870.4300

Chronic Inhalation Toxicity/Carcinogenicity-Rat. (2 year)	43755301
(1995)

Acceptable/guideline

0, 0.15, 0.5, or 1.0 ppm in a whole body inhalation chamber for 6
hrs/day, 5days/week for up to 108 weeks.	NOAEL =0.1 ppm (0.0007 mg/L)

LOAEL = 0.5 ppm (0.0034 mg/L), based on increased mortality rate and
decreased mean survival time in males, and transiently decreased body
weight gains in both sexes.

Port of entry NOAEL = 0.5 ppm

Port of entry LOAEL = 1.0 ppm (males), based on severe rhinitis of the
anterior nasal cavity.

870.5100

Bacterial Reverse Mutation Test (Ames Assay)	41960801 (1990)

Acceptable/guideline	S9-activated CP is Mutagenic in Salmonella
typhimurium strains TA98,and  TA100.

870.5300

Mutagenic-Lymphoma Mutation-Mouse	41960803 (1990)

Acceptable/guideline	CP ranging from 0.038 to 0.75 nL/mL-S9 and 0.89 to
16 nL/mL +S9 did not induce a mutagenic response in two independently
performed mouse lymphoma forward mutation assays.

870.5375

In Vitro Chromosomal Aberration in Chinese Hamster Ovary	41960802 (1990)

Acceptable/guideline

	Nonactivated doses of CP from 0.75 to 1 nL/mL induced a reproducible
and significant clastogenic response in Chinese hamster ovary (CHO)
cells harvested 12 hours post-treatment.

Nonactivated CP was clastogenic over a narrow range of cytotoxic
concentrations. CP in the absence of S9 activation is a clastogen in
this mammalian test system.

870.5395

Unscheduled DNA Synthesis-Rat	41960804 (1990)

Acceptable/guideline	CP was not genotoxic in primary rat hepatocytes
over a concentration range (0.3 to 6 nL/mL) that included moderately
cytotoxic levels. CP showed no evidence of UDS.

870.6200

Inhalation Acute  Neurotoxicity - Rats

Not required by the Agency

870.6200

Feeding Subchronic  Neurotoxicity - Rats

Not required by the Agency

870.7485

Metabolism - Rat

Not available.

870.7600

Dermal Penetration - Rat

Not required by the Agency

b.  Toxicity to Freshwater Aquatic Animals	

	i.  Freshwater Fish, Acute

Two freshwater fish toxicity studies using the TGAI are required to
establish the toxicity of chloropicrin to fish.   The preferred test
species are rainbow trout (a coldwater fish) and bluegill sunfish (a
warmwater fish).  Results of these tests are tabulated below. The
toxicity category descriptions for freshwater and estuarine/marine fish
and aquatic invertebrates, are defined below in parts per million (ppm).

If the LC50 is less than 0.1 ppm a.i., then the test substance is very
highly toxic.

If the LC50 is 0.1-to-1.0 ppm a.i., then the test substance is highly
toxic.

If the LC50 is greater than 1 and up through 10 ppm a.i., then the test
substance is moderately toxic.

If the LC50 is greater than 10 and up through 100 ppm a.i., then the
test substance is slightly toxic.

If the LC50 is greater than 100 ppm a.i., then the test substance is
practically nontoxic.

Table 3:  Freshwater Fish Acute Toxicity - Chloropicrin Technical

Species/

Flow-through or Static	% ai	LC50

 (ppb) 	Toxicity Category	MRID/Accession (ACC) No. Author/Year	Study
Classification

Bluegill Sunfish

(Lepomis macrochirus)/Static	99.0	<105	at least highly toxic	FTLR
439/McCann/1972	Suppl.

Bluegill Sunfish

(Lepomis macrochirus)/Static-renewal	99.88	44.1	Very highly toxic
471021-03Flatman and Billing/2004	Suppl.

Rainbow Trout

(Oncorhynchus sp.)/Static	99.0	< 16.98	Very highly toxic	FTLR
425/McCann/1971

	Suppl.

Rainbow Trout

(Oncorhynchus mykiss)/Static-renewal	99.88	5.14	Very highly toxic
471021-02Flatman and Billing/2004	Suppl.

The requirement for two freshwater fish acute toxicity studies has not
been satisfied.  Flow-through studies with measured concentrations are
needed to reduce uncertainty in the risk assessment.

	ii.  Freshwater Fish, Chronic

A freshwater fish early life-stage test  is required for chloropicrin
since it is expected to be transported to water from the intended use
site, and one or more of the following conditions are met: (1) the
pesticide is intended for use such that its presence in water is likely
to be continuous or recurrent, (2) any aquatic acute LC50 or EC50 is
less than 1 ppm, and/or (3) the EEC in water is equal to or greater than
0.01 of any acute LC50 or EC50 value.   The preferred test species is
rainbow trout. 

The fish early life-stage is a laboratory test designed to estimate the
quantity of toxicant required to adversely effect the reproduction of a
test population of fish.  The test should be performed using
flow-through conditions.   The test material is administered into water
containing the test species, providing exposure throughout a critical
life-stage, and the results, generally, are expressed as a No Observed
Adverse Effect Concentration (NOAEC) in parts per million or parts per
billion of active ingredient.  The No Observed Adverse Effect
Concentration  represents an exposure concentration, at or below which
biologically significant effects will not occur to species of similar
sensitivities. 

	(iii)	Freshwater Invertebrates, Acute

A freshwater aquatic invertebrate toxicity test using the TGAI is
required to establish the toxicity of chloropicrin to aquatic
invertebrates. The preferred test organism is Daphnia magna, but early
instar amphipods, stoneflies, mayflies, or midges may also be used.   
Results of this test are tabulated below. 

Table 5:  Freshwater Invertebrate Acute Toxicity - Chloropicrin 

Species/

Flow-through or Static	% ai	LC50/EC50 (ppb) 	Toxicity Category
MRID/Accession (ACC) No. Author/Year	Study Classification

Daphnid

(Daphnia pulex)/static	> 96.5	< 71	very highly toxic	130704/Cody and
Shema/1983	Supplemental

Daphnid

(Daphnia magna)/static	99.88	170	Highly toxic	471021-01/Flatman and
Billing/2004	Supplemental

1    Core (study satisfies guideline).  Supplemental (study is
scientifically sound, but does not satisfy guideline).

The requirement for an acute freshwater invertebrate acute toxicity
study has not been satisfied.  A flow-through study with measured
concentrations is needed to reduce uncertainty in the risk assessment.

	iv.  Freshwater Invertebrate, Chronic

A freshwater aquatic invertebrate life-cycle test is required for
chloropicrin because this degradate is expected to be transported to
water from the intended use site, and one or more of the following
conditions are met: (1) the pesticide is intended for use such that its
presence in water is likely to be continuous or recurrent, (2) any
aquatic acute LC50 or EC50 is less than 1ppm, and/or (3) the EEC in
water is equal to or greater than 0.01 of any acute LC50 or EC50 value. 
A flow-through study with measured concentrations is needed for risk
assessment. 

c.  Toxicity to Estuarine and Marine Animals

	i.  Estuarine and Marine Fish, Acute

	Acute toxicity testing with estuarine/marine fish is required for
chloropicrin since the active ingredient and or degradates are expected
to reach the marine/estuarine environment due to its expected use in
coastal counties.  The preferred test species is the sheepshead minnow. 

	ii.  Estuarine and Marine Fish, Chronic

	An estuarine/marine fish early life-stage toxicity test using
chloropicrin is reserved, pending submission and review of freshwater
fish chronic testing. 

	iii.  Estuarine and Marine Invertebrates, Acute

	Acute toxicity testing with estuarine/marine invertebrates is required
for chloropicrin because it is expected to reach the marine/estuarine
environment due to its expected use in coastal counties.  The preferred
test species are mysid shrimp and eastern oyster. 

	iv.  Estuarine and Marine Invertebrate, Chronic

	An estuarine/marine invertebrate life-cycle toxicity test (Guideline
72-4b) using chloropicrin is reserved, pending submission and review of
freshwater invertebrate chronic testing.

	d.  Toxicity to Plants

	i.  Terrestrial Plants

	Terrestrial plant Tier I seedling emergence and vegetative vigor
testing of a  Typical End-Use product (TEP) is currently recommended for
all pesticides having outdoor uses (EFED Policy, Keehner. July 1999). 
For seedling emergence and vegetative vigor testing, the following plant
species and groups should be tested: (1) six species of at least four
dicotyledonous families, one species of which is soybean (Glycine max)
and the second is a root crop, and (2) four species of at least two
monocotyledonous families, one of which is corn (Zea mays).  Tier I
tests measure the response of plants, relative to a control, at a test
level that is equal to the highest use rate expressed as pounds active
ingredeint per acre (lbs ai/A).  Tier II studies are required if the
Tier I studies indicate any of the test species, when exposed to the
test material, displayed a ≥25% inhibition or over-enhancement of
various growth parameters as compared to the control.  This guideline
has not been satisfied.

			

	ii.  Aquatic Plants

	Aquatic plant testing is recommended for all pesticides having outdoor
uses (EFED Policy, Keehner. July 1999).  The tests are performed on
species from a cross-section of the  aquatic plant population.  The
preferred test species are duckweed (Lemna gibba), marine diatom
(Skeletonema costatum), blue-green algae (Anabaena flos-aquae),
freshwater green alga (Selenastrum capricornutum), and a freshwater
diatom.  Tier I aquatic plant testing is a maximum dose test designed to
quickly evaluate the toxic effects to the test species in terms of
growth and reproduction and to determine the need for additional aquatic
plant testing.  Tier II aquatic plant testing is a multiple dose test of
the plants species that showed a phytotoxic effect to the pesticide
being tested at the Tier I level.  Tier II testing is designed to
determine the detrimental effect levels of the chemical on the aquatic
plants which showed a greater than 50% detrimental effect in Tier I
testing.

e.  Toxicity to Non-target Insects

An acute contact study with the honey bee (141-1) is required, since the
proposed uses are outdoors.  

	Appendix D.  The  Risk Quotient Method and Levels of Concern  TC
"Appendix D.  The  Risk Quotient Method and Levels of Concern" \f C \l
"2"  

	Risk characterization integrates the results of the exposure and
ecotoxicity data to evaluate the likelihood of adverse ecological
effects.  The means of this integration is called the quotient method. 
Risk quotients (RQs) are calculated by dividing exposure estimates by
acute and chronic ecotoxicity values.  

	RQ = EXPOSURE/TOXICITY

	RQs are then compared to OPP's levels of concern (LOCs).  These LOCs
are used by OPP to analyze potential risk to nontarget organisms and the
need to consider regulatory action.  The criteria indicate that a
pesticide used as directed has the potential to cause adverse effects on
nontarget organisms.  LOCs currently address the following risk
presumption categories: (1) acute risks - regulatory action may be
warranted in addition to restricted use classification, (2) acute
restricted use - the potential for acute risk is high, but may be
mitigated through restricted use classification, (3) acute endangered
species - endangered species may be adversely affected, and (4) chronic
risk - the potential for chronic risk is high regulatory action may be
warranted.   Currently, EFED does not perform assessments for chronic
risk to plants, acute or chronic risks to  insects, or chronic risk from
granular/bait formulations to birds or mammals.

	The ecotoxicity test values (measurement endpoints) used in the acute
and chronic risk quotients are derived from required studies.  Examples
of ecotoxicity values derived from short-term laboratory studies that
assess acute effects are: (1) LC50 (fish and birds), (2) LD50 (birds and
mammals), (3) EC50 (aquatic plants and aquatic invertebrates) and (4)
EC25 (terrestrial plants).  Examples of toxicity test effect levels
derived from the results of long-term laboratory studies that assess
chronic effects are: (1) LOAEL or LOAEC (birds, fish, and aquatic
invertebrates) and (2) NOAEL or NOAEC (birds, fish and aquatic
invertebrates).  For birds, mammals, fish and aquatic invertebrates the
NOAEL or NOAEC generally is used as the ecotoxicity test value in
assessing chronic effects, although other values may be used when
justified.  Risk presumptions and the corresponding RQs and LOCs, are
tabulated below.

	

Table 1.  Risk presumptions for terrestrial animals  based on risk
quotients (RQ) and levels of concern (LOC).

Risk Presumption	RQ	LOC

Birds

Acute Risk 	EEC1/LC50 or LD50/ft2 or LD50/day3	0.5

Acute Restricted Use	EEC/LC50 or LD50/ft2 or LD50/day (or LD50 < 50
mg/kg)	0.2

Acute Endangered Species	EEC/LC50 or LD50/ft2 or LD50/day 	0.1

Chronic Risk	EEC/NOAEC	1

Wild Mammals

Acute Risk 	EEC/LC50 or LD50/ft2 or LD50/day		0.5

Acute Restricted Use	EEC/LC50 or LD50/ft2 or LD50/day (or LD50 < 50
mg/kg)	0.2

Acute Endangered Species	EEC/LC50 or LD50/ft2 or LD50/day		0.1

Chronic Risk 	EEC/NOAEC	1

 1  abbreviation for Estimated Environmental Concentration (ppm) on
avian/mammalian food items

 2  mg/ft2

 3  mg of toxicant consumed/day

  LD50 * wt. of bird

  LD50 * wt. of bird  

Table 2.  Risk presumptions for aquatic animals based on risk quotients
(RQ) and levels of concern (LOC).

Risk Presumption	RQ 	LOC

Acute Risk	EEC1/LC50 or EC50	0.5

Acute Restricted Use	EEC/LC50 or EC50	0.1

Acute Endangered Species	EEC/LC50 or EC50	0.05

Chronic Risk	EEC/NOAEC	1

 1  EEC = (ppm or ppb) in water

Table 3.  Risk presumptions for plants based on risk quotients (RQ) and
levels of concern (LOC).

Risk Presumption	RQ	LOC

Terrestrial and Semi-Aquatic Plants 

Acute Risk	EEC1/EC25	1

Acute Endangered Species	EEC/EC05 or NOAEC	1

		Aquatic Plants

Acute Risk	EEC2/EC50	1

Acute Endangered Species	EEC/EC05 or NOAEC 	1

1  EEC = lbs ai/A 

2  EEC = (ppb/ppm) in water 

	Appendix E.    Data Requirement Tables  TC "Appendix E.    Data
Requirement Tables" \f C \l "2"  

	Table A1(A). Ecological Effects Data Requirements for: Chloropicrin    
                                 

Guideline #	

Data Requirement	Are Additional Data Needed for Risk Assessment?	

MRID #’s	Study Classification

  71-1(a)	Avian Acute Oral	Y	------------	------------

------	Avian Acute Inhalation	Y	------------	-----------

71-2(a)	Avian Dietary–quail	N	------------	------------

71-2(b)	Avian Dietary–mallard	N	------------	-------------

---------	Avian Subchronic/Chronic Inhalation 	Y	-------------
-------------

72-1(a)	Fish Acute Toxicity–bluegill	Y	FTLR 439

471021-03	S

S

72-1(b)	Fish Acute Toxicity–rainbow trout	Y	FTLR 425

471021-02	S

S

72-2(a)	Aquatic Invertebrate Acute Toxicity–freshwater	Y	130704

471021-01	S

S

72-3(a)	Marine/Estuarine Acute Toxicity–Fish	Y	-------------
-------------

72-3(b)	Marine/Estuarine Acute Toxicity–Mollusk (shell deposition)	Y
------------

	-------------

72-3(c)	Marine/Estuarine Acute Toxicity–Shrimp	Y	------------
-------------

72-4(a)	Fish Early Life Stage–freshwater	Y	-------------	-------------

72-4(a)	Fish Early Life Stage– marine/estuarine	Reserved	------------
-------------

72-4(b)	Aquatic Invertebrate Life Cycle–freshwater 	Y	-----------
------------

123-1(a)	Seedling Germination/Seedling Emergence–Tier II 	Y
-------------	------------

123-1(b)	Vegetative Vigor–Tier II 	Y	-------------	------------

123-2	Aquatic Plant Growth – Tier II	Y

-----------

141-1	Honeybee Acute Contact 	Y	-------------	------------

A=Acceptable; S=Supplemental; U=Unnaceptable; W=Waived; N/A=Not
Applicable; NA=Not Available; Inv.=Invalid; R=Potentially Repairable

Table 1A (B). Environmental Fate Data Requirements for: Chloropicrin

Guideline #	

Data Requirement	Is Data Requirement Satisfied?	

MRID #’s	Study Classification

161-1	Hydrolysis	Y	43022401	A

161-2	Photodegradation in Water	Y	42900201	S

161-3	Photodegradation on Soil	N/A	NA	W

161-4	Photodegradation in Air	Y	05007865	A

162-1	Aerobic Soil Metabolism	Y	43613901	A

162-2	Anaerobic Soil Metabolism	N/A	----------	----------

162-3	Anaerobic Aquatic Metabolism	Y	43759301	A

162-4	Aerobic Aquatic Metabolism	N/A	----------	----------

163-1	Mobility-Column Leaching	Y	44191301	S

163-2	Laboratory Volatility	Y	43798601	A

163-3	Field Volatility	Reserved	----------	----------

164-1	Terrestrial Field Dissipation	N	43085101	S

165-4	Accumulation in Fish/

Bioconcentration	N/A	NA	W

A=Acceptable; S=Supplemental; U=Unnaceptable; W=Waived; N/A=Not
Applicable; NA=Not Available

Appendix F	Terrestrial Exposure Modeling-PERFUM  TC "Appendix B
Terrestrial Exposure Modeling-PERFUM" \f C \l "2"  

** PERFUM Output File 

******************************************************

 Version 2.1.3 - compiled on 12/11/2006

	 Run finished on: 03/16/2007 at 00:18

	******************************************************

** Basic information about the model run 

	******************************************************

 Scenario Type: SF 

	 Source of flux data: CDPR Commodity Permit Conditions                 

 Source of meteorological data: 

 Bakersfield, CA     

Venture, CA

 Field size (acres):   39.976

 Length in x-direction (m):   402.30

	 Length in y-direction (m):   402.30

	 Grid density: FINE    

	******************************************************

** Exposure Assumptions

******************************************************

 Exposure averaging period (hours):   4

	 Distribution averaging time (hours):   4

	

--------- PERFUM Model Results -----------

 Concentration distribution results for rings  the field

 Ring No.   Distance (meters)

____________________________________

  1             5.

	  2             7.

	  3            10.

	  4            15.

	  5            20.

	  6            30.

	  7            50.

	  8            70.

	  9            80.

	 10            90.

	

Bakerfields: 40 acre bedded tarped @ 350lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	583	583	573	554	544	505	446	387	368	348

	Period 2	90	985	975	965	936	907	858	750	671	642	613

	Period 3	90	1254	1254	1235	1191	1152	1073	916	799	750	701

	Period 4	90	1063	1044	1005	936	887	779	632	534	495	456

	Period 5	90	946	926	877	809	760	662	544	456	426	397

	Period 6	90	1744	1725	1686	1607	1548	1411	1201	1034	965	907

Day 2	Period 1	90	2920	2920	2881	2803	2724	2548	2234	1960	1862	1784

	Period 2	90	1764	1744	1725	1686	1627	1548	1352	1181	1112	1054

	Period 3	90	1201	1191	1171	1132	1093	1014	877	779	740	711

	Period 4	90	632	613	593	554	524	466	368	309	289	270

	Period 5	90	279	270	250	230	221	191	152	132	123	113

	Period 6	90	319	309	299	289	279	250	211	181	162	152

Bakerfields: 40 acre bedded untarped @ 175 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	1548.4	1528.8	1470	1391.6	1313.2	1190.7	984.9	837.9
779.1	730.1

	Period 2	90	2802.8	2783.2	2744	2685.2	2606.8	2430.4	2116.8	1881.6	1764
1666

	Period 3	90	2175.6	2156	2136.4	2097.2	2038.4	1901.2	1666	1470	1391.6
1332.8

	Period 4	90	994.7	994.7	975.1	945.7	916.3	857.5	739.9	651.7	612.5	583.1

	Period 5	90	367.5	357.7	347.9	328.3	318.5	279.3	230.3	191.1	181.3	171.5

	Period 6	90	151.9	142.1	132.3	122.5	112.7	102.9	83.3	63.7	63.7	53.9

Day 2	Period 1	90	122.5	122.5	122.5	112.7	102.9	93.1	73.5	63.7	63.7	53.9

	Period 2	90	200.9	200.9	200.9	200.9	191.1	181.3	151.9	132.3	132.3	122.5

	Period 3	90	200.9	200.9	200.9	191.1	181.3	171.5	151.9	132.3	132.3	122.5

	Period 4	90	171.5	171.5	171.5	161.7	161.7	151.9	132.3	112.7	102.9	102.9

	Period 5	90	44.1	44.1	44.1	44.1	34.3	34.3	24.5	24.5	24.5	14.7

	Period 6	90	24.5	14.7	14.7	14.7	14.7	14.7	14.7	4.9	4.9	4.9



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348	319	279	221	181	172	162

Day 2	Period 1	90	397	387	368	348	328	289	240	201	191	172

	Period 2	90	1122	1122	1103	1073	1034	975	838	730	681	642

	Period 3	90	1274	1254	1235	1210	1181	1103	975	877	828	779

	Period 4	90	858	848	838	809	789	740	642	564	524	505

	Period 5	90	436	426	417	397	377	348	299	250	240	221

	Period 6	90	142	142	132	123	113	93	74	64	54	54

Bakerfields: 40 acre Broadcast tarped @ 350 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	534	524	495	466	436	387	319	270	250	230

	Period 2	90	622	613	593	573	544	495	417	358	338	319

	Period 3	90	466	466	456	446	436	407	358	309	299	279

	Period 4	90	740	740	730	711	691	642	554	485	456	436

	Period 5	90	2528	2509	2450	2352	2234	2038	1686	1431	1333	1235

	Period 6	90	2117	2058	1960	1803	1686	1490	1191	1005	926	858

Day 2	Period 1	90	1568	1529	1450	1352	1274	1122	926	789	730	681

	Period 2	90	1588	1568	1529	1450	1372	1254	1054	907	838	789

	Period 3	90	720	720	711	691	671	632	544	485	456	436

	Period 4	90	720	720	711	691	671	632	544	475	456	426

	Period 5	90	1705	1686	1646	1568	1490	1372	1152	975	907	838

	Period 6	90	1352	1313	1235	1152	1073	946	760	632	593	544



Bakerfields: 40 acre Drip tarped @ 300 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	221	211	201	191	181	162	123	103	103	93

	Period 2	90	289	289	270	250	230	211	172	142	132	123

	Period 3	90	701	691	681	652	622	564	475	417	387	358

	Period 4	90	83	83	83	83	74	74	64	54	54	44

	Period 5	90	93	83	83	83	83	74	64	54	54	54

	Period 6	90	83	83	83	83	74	74	64	54	54	44

Day 2	Period 1	90	74	74	74	64	64	54	44	34	34	34

	Period 2	90	83	83	83	74	74	64	54	44	34	34

	Period 3	90	201	201	191	191	181	162	142	123	113	103

	Period 4	90	5	5	5	5	5	5	5	5	5	5

	Period 5	90	5	5	5	5	5	5	5	5	5	5

	Period 6	90	5	5	5	5	5	5	5	5	5	5

Salinas Bakerfields: 40 acre Drip tarped @ 300 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	309	299	289	270	250	221	181	152	142	132

	Period 2	90	573	554	534	495	456	397	328	270	250	240

	Period 3	90	319	319	309	299	279	260	221	191	172	162

	Period 4	90	123	123	123	113	113	103	93	83	74	74

	Period 5	90	113	113	103	103	103	93	83	74	64	64

	Period 6	90	54	54	54	54	54	44	44	34	34	34

Day 2	Period 1	90	83	74	74	74	64	54	44	34	34	34

	Period 2	90	93	93	83	74	74	64	54	44	34	34

	Period 3	90	74	74	74	74	64	64	54	44	44	34

	Period 4	90	44	44	44	44	44	34	34	25	25	25

	Period 5	90	15	15	15	15	15	15	15	15	15	5

	Period 6	90	15	15	15	15	15	15	15	5	5	5



Ventura: 40 acre bedded tarped @ 350lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	632	622	613	583	564	524	456	407	387	368

	Period 2	90	1103	1093	1073	1034	1005	936	838	750	711	671

	Period 3	90	1372	1352	1333	1274	1220	1132	975	858	809	760

	Period 4	90	1054	1024	985	926	867	769	632	534	495	466

	Period 5	90	828	809	779	740	691	622	515	446	417	387

	Period 6	90	1509	1470	1431	1352	1274	1142	936	799	740	691

Day 2	Period 1	90	3195	3156	3077	2960	2842	2626	2313	2058	1940	1842

	Period 2	90	1940	1921	1882	1823	1764	1666	1431	1254	1191	1122

	Period 3	90	1274	1254	1235	1171	1122	1054	926	818	769	730

	Period 4	90	622	603	583	544	505	456	368	309	289	270

	Period 5	90	240	240	230	221	201	181	152	132	123	113

	Period 6	90	270	260	250	240	221	201	162	132	123	113

Ventura: 40 acre bedded untarped @ 175 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	1235	1220	1161	1093	1024	916	750	642	593	564

	Period 2	90	2881	2862	2803	2685	2587	2411	2078	1803	1686	1588

	Period 3	90	2470	2450	2411	2332	2254	2097	1803	1588	1490	1392

	Period 4	90	1073	1054	1034	985	946	877	769	691	662	632

	Period 5	90	368	368	348	328	309	279	240	201	191	172

	Period 6	90	132	132	123	113	113	93	83	64	64	54

Day 2	Period 1	90	103	93	93	83	83	74	64	54	44	44

	Period 2	90	211	211	201	201	191	172	152	132	123	113

	Period 3	90	230	221	221	211	201	191	172	152	142	132

	Period 4	90	181	181	181	172	162	152	132	123	113	103

	Period 5	90	44	44	44	44	34	34	25	25	25	25

	Period 6	90	5	5	5	5	5	5	5	5	5	5



Ventura: 40 acre Broadcast tarped @ 350 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	456	446	426	407	387	338	289	250	230	221

	Period 2	90	564	554	534	505	475	426	358	299	279	260

	Period 3	90	534	524	515	495	475	436	387	348	328	319

	Period 4	90	818	809	799	769	740	681	593	534	505	485

	Period 5	90	2764	2724	2666	2548	2411	2195	1842	1588	1470	1392

	Period 6	90	2019	1960	1882	1744	1627	1450	1181	1005	936	877

Day 2	Period 1	90	1333	1313	1254	1191	1122	1005	838	730	681	642

	Period 2	90	1411	1372	1333	1254	1181	1054	858	730	671	632

	Period 3	90	828	818	799	769	730	681	593	534	505	485

	Period 4	90	809	799	779	760	720	671	583	524	495	475

	Period 5	90	1842	1823	1784	1705	1627	1470	1235	1073	1005	936

	Period 6	90	1294	1254	1191	1112	1044	916	750	642	593	554

Ventura: 40 acre Broadcast untarped @ 175 lbs a.i./acre

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	338	328	319	299	279	250	211	181	172	162

	Period 2	90	3175	3136	3077	2979	2842	2607	2215	1901	1764	1666

	Period 3	90	4219	4190	4072	3954	3837	3665	3293	2960	2803	2646

	Period 4	90	1705	1686	1646	1588	1529	1392	1220	1093	1044	995

	Period 5	90	985	965	936	897	848	769	652	564	524	495

	Period 6	90	377	368	348	328	309	270	221	191	181	162

Day 2	Period 1	90	319	309	299	279	270	240	201	172	162	152

	Period 2	90	1122	1112	1093	1044	1005	916	779	671	622	583

	Period 3	90	1490	1470	1450	1392	1352	1274	1132	1014	965	916

	Period 4	90	946	936	916	877	848	779	671	603	573	544

	Period 5	90	436	426	417	387	368	338	279	240	221	211

	Period 6	90	132	123	123	113	103	93	74	64	64	54

Ventura: 40 acre Drip tarped @ 300 lbs a.i./acre	 

Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8	Ring9
Ring10

Day1	Period 1	90	211	211	201	191	172	152	123	103	103	93

	Period 2	90	250	240	230	221	211	181	152	132	123	113

	Period 3	90	603	593	573	544	505	456	377	319	299	270

	Period 4	90	93	93	83	83	83	74	64	54	54	54

	Period 5	90	103	103	93	93	93	83	74	64	64	54

	Period 6	90	93	83	83	83	83	74	64	54	54	44

Day 2	Period 1	90	74	74	74	64	64	54	44	34	34	34

	Period 2	90	74	74	74	64	64	54	44	34	34	34

	Period 3	90	172	172	162	152	142	132	103	93	83	74

	Period 4	90	5	5	5	5	5	5	5	5	5	5

	Period 5	90	15	15	15	15	5	5	5	5	5	5

	Period 6	90	5	5	5	5	5	5	5	5	5	5

Ventura (Salinas) : 40 acre Drip tarped @ 300 lbs a.i./acre	 

	Days	Periods	%tile	Ring1	Ring2	Ring3	Ring4	Ring5	Ring6	Ring7	Ring8
Ring9	Ring10

Day1	Period 1	90	309	299	289	270	250	221	181	152	142	132

	Period 2	90	505	495	475	446	426	377	319	270	250	240

	Period 3	90	279	270	260	250	230	211	172	142	132	123

	Period 4	90	132	132	132	123	123	113	93	83	83	74

	Period 5	90	123	123	123	113	113	103	93	83	74	74

	Period 6	90	54	54	54	54	54	44	44	34	34	34

Day 2	Period 1	90	83	74	74	74	64	54	44	34	34	34

	Period 2	90	83	83	74	74	64	54	44	44	34	34

	Period 3	90	64	64	64	54	54	44	34	34	34	25

	Period 4	90	44	44	44	44	44	44	34
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