Document ID: EPA-HQ-OPP-2006-0661-0005
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-11-29T05:00Z

Revised Level I Screening Ecological Risk Assessment

	for the Reregistration of Chloropicrin

	

	

		

	

	

				

Prepared by:

Faruque Khan, Environmental 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

Nick Federoff, Wildlife Biologist

Jean Holmes, RAPL

Mah Shamim, Branch Chief

	Table of Contents 

  TOC \f \* MERGEFORMAT \l "1-5"  

I.  Executive Summary	  HYPERLINK \l Generated Bookmark1 1 

A.  Nature of Chemical Stressor	  HYPERLINK \l Generated Bookmark2 1 

B.  Conclusions - Exposure Characterization	  HYPERLINK \l Generated
Bookmark3 1 

C.  Potential Risks to Non-target Organisms	  HYPERLINK \l Generated
Bookmark4 2 

D.  Conclusions - Effects Characterization	  HYPERLINK \l Generated
Bookmark5 3 

E.  Data Gaps and Uncertainties	  HYPERLINK \l Generated Bookmark6 3 

1. Environmental Fate and Exposure	  HYPERLINK \l Generated Bookmark7 3 

2. Ecological Effects	  HYPERLINK \l Generated Bookmark8 4 

II.  Problem Formulation	  HYPERLINK \l Generated Bookmark9 7 

A.  Stressor Source and Distribution	  HYPERLINK \l Generated Bookmark10
7 

1.  Source and Intensity	  HYPERLINK \l Generated Bookmark11 7 

2.  Physical/Chemical/Fate and Transport Properties	  HYPERLINK \l
Generated Bookmark12 7 

3.  Pesticide Type, Class, and Mode of Action	  HYPERLINK \l Generated
Bookmark13 7 

4.  Overview of Pesticide Usage	  HYPERLINK \l Generated Bookmark14 7 

B.  Receptors	  HYPERLINK \l Generated Bookmark15 8 

1.  Ecological Effects	  HYPERLINK \l Generated Bookmark16 8 

2.  Ecosystems Potentially At Risk	  HYPERLINK \l Generated Bookmark17
10 

C.  Assessment Endpoints	  HYPERLINK \l Generated Bookmark18 11 

D.  Conceptual Model	  HYPERLINK \l Generated Bookmark19 11 

1.  Risk Hypotheses	  HYPERLINK \l Generated Bookmark20 11 

2.  Diagram	  HYPERLINK \l Generated Bookmark21 11 

E.  Analysis Plan	  HYPERLINK \l Generated Bookmark22 14 

a.  Measures of Exposure	  HYPERLINK \l Generated Bookmark23 16 

b.  Measures of Effect	  HYPERLINK \l Generated Bookmark24 16 

c.  Measures of Ecosystem and Receptor Characteristics	  HYPERLINK \l
Generated Bookmark25 17 

III.  Analysis	  HYPERLINK \l Generated Bookmark26 18 

A.  Use Characterization	  HYPERLINK \l Generated Bookmark27 18 

B.  Exposure Characterization	  HYPERLINK \l Generated Bookmark28 20 

1.  Environmental Fate and Transport Characterization	  HYPERLINK \l
Generated Bookmark29 20 

(a) Fate and Transport in soil and water	  HYPERLINK \l Generated
Bookmark30 22 

(b) Fate and Transport in atmosphere	  HYPERLINK \l Generated Bookmark31
23 

(c) Ozone Depletion Potential	  HYPERLINK \l Generated Bookmark32 25 

	2.  Measures of Terrestrial Exposure	  HYPERLINK \l Generated
Bookmark33 25 

(a)Terrestrial Exposure Modeling	  HYPERLINK \l Generated Bookmark34 25 

(b) Terrestrial Exposure Monitoring Data	  HYPERLINK \l Generated
Bookmark35 27 

3.  Measures of Aquatic Exposure	  HYPERLINK \l Generated Bookmark36 29 

a.  Aquatic Exposure Modeling	  HYPERLINK \l Generated Bookmark37 29 

b.  Aquatic Exposure Monitoring and Field Data	  HYPERLINK \l Generated
Bookmark38 32 

C.  Ecological Effects Characterization	  HYPERLINK \l Generated
Bookmark39 32 

1.  Aquatic Effects Characterization	  HYPERLINK \l Generated Bookmark40
33 

a.  Aquatic Animals	  HYPERLINK \l Generated Bookmark41 33 

2.  Terrestrial Effects Characterization	  HYPERLINK \l Generated
Bookmark42 34 

a.  Terrestrial Animals	  HYPERLINK \l Generated Bookmark43 34 

IV.  Risk Characterization	  HYPERLINK \l Generated Bookmark44 36 

A.  Risk Estimation - Integration of Exposure and Effects Data	 
HYPERLINK \l Generated Bookmark45 36 

1.  Non-target Aquatic Animals and Plants	  HYPERLINK \l Generated
Bookmark46 36 

2.  Non-target Terrestrial Animals	  HYPERLINK \l Generated Bookmark47
37 

a. Risk to Mammals	  HYPERLINK \l Generated Bookmark48 37 

b. Risk to Avian Species	  HYPERLINK \l Generated Bookmark49 38 

3.  Non-target Terrestrial and Semi-aquatic Plants	  HYPERLINK \l
Generated Bookmark50 38 

B.  Risk Description	  HYPERLINK \l Generated Bookmark51 39 

1.  Risk to Aquatic Organisms	  HYPERLINK \l Generated Bookmark52 39 

A.  Animals	  HYPERLINK \l Generated Bookmark53 39 

B.  Plants	  HYPERLINK \l Generated Bookmark54 40 

2.  Risk to Terrestrial Organisms	  HYPERLINK \l Generated Bookmark55 40

A.  Animals	  HYPERLINK \l Generated Bookmark56 40 

B.  Plants	  HYPERLINK \l Generated Bookmark57 42 

3.  Review of Incident Data	  HYPERLINK \l Generated Bookmark58 42 

4.  Endocrine Disruption	  HYPERLINK \l Generated Bookmark59 43 

5.  Federally Threatened and Endangered (Listed) Species Concerns	 
HYPERLINK \l Generated Bookmark60 44 

A.  Action Area	  HYPERLINK \l Generated Bookmark61 44 

B. Taxonomic Groups Potentially at Risk	  HYPERLINK \l Generated
Bookmark62 44 

1.  Discussion of Risk Quotients	  HYPERLINK \l Generated Bookmark63 45 

2.  Probit Dose Response Relationship	  HYPERLINK \l Generated
Bookmark64 45 

C.  Data Related to Under-represented Taxa	  HYPERLINK \l Generated
Bookmark65 46 

D.  Implications of Sublethal Effects	  HYPERLINK \l Generated
Bookmark66 46 

E.  Indirect Effects Analysis	  HYPERLINK \l Generated Bookmark67 46 

F.  Critical Habitat	  HYPERLINK \l Generated Bookmark68 47 

G.  Co-occurrence Analysis	  HYPERLINK \l Generated Bookmark69 48 

V. Literature Cited	  HYPERLINK \l Generated Bookmark70 49 

VI. Appendices	  HYPERLINK \l Generated Bookmark71 54 

Appendix A.  Environmental Fate and Transport Data	  HYPERLINK \l
Generated Bookmark72 54 

Appendix B. Aquatic Exposure PRZM/EXAMS Modeling	  HYPERLINK \l
Generated Bookmark73 62 

Appendix C:  Ecological Effects Data	  HYPERLINK \l Generated Bookmark74
83 

a.  Toxicity to Terrestrial Animals	  HYPERLINK \l Generated Bookmark75
83 

i.  Birds, Acute and Subacute	  HYPERLINK \l Generated Bookmark76 83 

ii.  Birds, Chronic	  HYPERLINK \l Generated Bookmark77 84 

iii.  Mammalian Toxicity Data (from HED)	  HYPERLINK \l Generated
Bookmark78 84 

b.  Toxicity to Freshwater Aquatic Animals	  HYPERLINK \l Generated
Bookmark79 91 

i.  Freshwater Fish, Acute	  HYPERLINK \l Generated Bookmark80 91 

ii.  Freshwater Fish, Chronic	  HYPERLINK \l Generated Bookmark81 91 

(iii)	Freshwater Invertebrates, Acute	  HYPERLINK \l Generated
Bookmark82 92 

iv.  Freshwater Invertebrate, Chronic	  HYPERLINK \l Generated
Bookmark83 92 

c.  Toxicity to Estuarine and Marine Animals	  HYPERLINK \l Generated
Bookmark84 92 

	i.  Estuarine and Marine Fish, Acute	  HYPERLINK \l Generated
Bookmark85 92 

	ii.  Estuarine and Marine Fish, Chronic	  HYPERLINK \l Generated
Bookmark86 93 

	iii.  Estuarine and Marine Invertebrates, Acute	  HYPERLINK \l
Generated Bookmark87 93 

	iv.  Estuarine and Marine Invertebrate, Chronic	  HYPERLINK \l
Generated Bookmark88 93 

d.  Toxicity to Plants	  HYPERLINK \l Generated Bookmark89 93 

i.  Terrestrial Plants	  HYPERLINK \l Generated Bookmark90 93 

ii.  Aquatic Plants	  HYPERLINK \l Generated Bookmark91 93 

Appendix D.  The  Risk Quotient Method and Levels of Concern	  HYPERLINK
\l Generated Bookmark92 95 

	Appendix E.    Data Requirement Tables	  HYPERLINK \l Generated
Bookmark93 97  

												

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 \l1 "I.  Executive Summary 

	A.  Nature of Chemical Stressor  TC \l2 "A.  Nature of Chemical
Stressor  

	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 is 350 lbs ai/A, with 300 lbs
ai/A the maximum for drip irrigation. 

	B.  Conclusions - Exposure Characterization  TC \l2 "B.  Conclusions -
Exposure Characterization 

	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 4.5  to 10 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 \l2 "C.  Potential
Risks to Non-target Organisms 

	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
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 all modeled scenarios and for aquatic
invertebrates for three 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

	Of the six modeled scenarios, chloropicrin exceeds Levels-of-Concern
(acute endangered species, acute restricted use, and/or acute risk) 1)
for fish, with all six scenarios (California tomatoes,  California
onions, Florida tomatoes, Florida strawberries, North Carolina sweet
potatoes, and North Carolina tobacco; risk quotients range from >0.09 to
>6.35), and 2) for aquatic invertebrates, with California tomatoes,
Florida tomatoes and Florida strawberries (risk quotients range from
>0.05 to >1.52 for these crops).  Since all toxicity values are
considered to be less than the calculated numeric values (because of
absent or inadequately measured residues of this volatile chemical),
risk quotients are all expressed as greater than the quotient numeric
values.  EFED thus cannot confirm that any use pattern does not 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.  Thus, the above use sites are simply examples of sites that
would exceed one or more LOCs even if the actual toxicity values were
not lower (i.e., more toxic) than the values used for the risk quotient
calculations.  These risks would also apply to other aquatic animals
such as aquatic phase amphibians.  However, in addition to this
uncertainty concerning the toxicity of chloropicrin to aquatic animals
(i.e., with toxicity values expressed as less than the calculated
values, EFED considers chloropicrin to be more toxic than these values),
there are also substantial uncertainties concerning exposure modeling
values, as described below (in Data Gaps and Uncertainties).	

		Risks to Terrestrial Animals

	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 LOCs for acute
risk to endangered species for mammals.  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.

		Risks to Aquatic and Terrestrial Plants

	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 \l2 "D.  Conclusions -
Effects Characterization 

	Based on very limited data, chloropicrin is considered very highly
toxic to both fish (lowest LC50 < 16.98 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 \l2 "E.  Data Gaps and
Uncertainties 

		1. Environmental Fate and Exposure  TC \l3 "1. Environmental Fate and
Exposure 

	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. PRZM also has limited
capabilities in capturing the partitions of a volatile chemical in air,
water and sediment. 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.

	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 greater than 1 meter above the ground surface, actual
concentrations at ground level may differ from estimated air
concentration using ISCTS3 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 \l3 "2. Ecological Effects  

	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, with
indeterminate toxicity values.  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, with indeterminate toxicity
values.  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 \l1 " 

	A.  Stressor Source and Distribution  TC \l2 "A.  Stressor Source and
Distribution 		

		

		1.  Source and Intensity  TC \l3 "1.  Source and Intensity 

	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 \l3 "2. 
Physical/Chemical/Fate and Transport Properties 

		

	Chloropicrin is a clear, colorless, nonflammable oily liquid with
strong, sharp, highly irritating odor and a strong lacrimator. The high
vapor pressure (23.8 mm @ 25○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 \l3 "3.  Pesticide
Type, Class, and Mode of Action 

	

	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 \l3 "4.  Overview of Pesticide
Usage 

	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 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 \l2 "B.  Receptors 

		1.  Ecological Effects  TC \l3 "1.  Ecological Effects 

	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 \l3 "2.  Ecosystems Potentially
At Risk 

	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 \l2 "C.  Assessment Endpoints 

	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 \l2 "D.  Conceptual Model 

		1.  Risk Hypotheses  TC \l3 "1.  Risk Hypotheses 	

	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 \l3 "2.  Diagram 

		

	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 \l2 "  

		

	1. Preliminary Identification of Data Gaps and Methods

	The analysis plan is the final step in Problem Formulation and targets
the working hypotheses that are considered more likely to effect 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, with
indeterminate toxicity values (i.e., “<“).  

		2.  Measures to Evaluate Risk Hypotheses and Conceptual Model

				

			a.  Measures of Exposure  TC \l3 "a.  Measures of Exposure 

		

	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 Beta compiled May 24, 2001)  2001) simulates the fate of
the chemical in the field, including runoff and erosion on a daily time
step, and EXAMS (version 2.98.04 compiled November 2002) simulates the
environmental fate and transport processes in a body of surface water. A
graphical user interface (pe4v01.pl), 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). 

	Exposure concentrations for terrestrial ecosystems were based on
estimated atmospheric concentrations of chloropicrin using the
Industrial Source Complex - Short Term (ISCST3) air dispersion model
developed by USEPA (USEPA, 1995). 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 at
the edge of the fumigated field. 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 model 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
estimated maximum concentration of 0.019 mg/L (19037 μg/m3) was used in
calculating inhalation exposure for terrestrial organisms.

			b.  Measures of Effect  TC \l3 "b.  Measures of Effect 

	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 \l3 "c. 
Measures of Ecosystem and Receptor Characteristics 

	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 \l1 "III.  Analysis 

	A.  Use Characterization  TC \l2 "A.  Use Characterization 

	

	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 \l2 "B.  Exposure Characterization 

		1.  Environmental Fate and Transport Characterization  TC \l3 "1. 
Environmental Fate and Transport Characterization 

	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 4.5 to 10 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	-69.2̊C	Merck Index

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

Density	1.7 g/mL at 25 ̊C	Merck Index

Water solubility	1.612 g/L @ 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

Table 4. Environmental Fate  Properties of Chloropicrin

Parameter	Value	Reference/Comments

	Persistence

Hydrolysis t1/2	Stable at pH 5, 7, and 9	MRID# 43022401

Photolysis  t1/2 in water	1.3 days, degradates chloride, nitrate,
nitrite, and CO2	MRID# 42900201

Photolysis  t1/2 on soil	N/A	Waived

Photolysis  t1/2 in air	≤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

10 days

major degradate is CO2

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

MRID# 43613901

Aquatic metabolism  Anaerobic t1/2	1.3 hours

major degradates nitromethane and chloronitromethane	MRID# 43759301

Aquatic metabolism  Aerobic t1/2	N/A	Waived

	Mobility/Adsorption-Desorption

KOC	 36.05 L kg-1	EPISUITE

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

Tarped soil maximum volatility 

205 μg/cm2/hr	MRID# 43798601

	Field Dissipation

Terrestrial Field Dissipation	≤1.4 days from 3- to 12-inch depth from
a sandy loam and a sand from California, measured after tarp was removed
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 \l4 "(a) Fate and Transport
in soil and water 

	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 is 10 days with carbon dioxide
being the terminal breakdown product (MRID 43613901). 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:

		CCl3NO2   →  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.

	Chloropicrin is highly soluble in water and are 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 was less than 33.4hours. 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 \l4 "(b) Fate and Transport
in atmosphere 

	  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).

	An overall atmospheric lifetime for chloropicrin can be computed using
the procedure followed by USEPA 2005b, in which an overall ‛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 \l4 "(c) Ozone Depletion Potential 

	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 \l2 "	2.  Measures of
Terrestrial Exposure 

			(a)Terrestrial Exposure Modeling  TC \l4 "(a)Terrestrial Exposure
Modeling 

	 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 mg/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 \l4 "(b) Terrestrial
Exposure Monitoring Data 

	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 

= (1/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 \l3 "3.  Measures of Aquatic
Exposure 

a.  Aquatic Exposure Modeling  TC \l4 "a.  Aquatic Exposure Modeling  
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.

	Estimated environmental concentrations (EEC) of chloropicrin in surface
waters were calculated using PRZM v.3.12 (Pesticide Root Zone Model),
which simulates runoff and erosion from the agricultural field, and
EXAMS v.2.98 (Exposure Analysis Modeling System), which simulates
environmental fate and transport in surface water.  A graphical user
interface developed by EPA (  HYPERLINK
http://www.epa.gov/oppefed1/models/water/
http://www.epa.gov/oppefed1/models/water/  ) was employed to enter the
input values for each model run.  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,	15.71 days 	Calculated 90th Percentile

MRID#s 43613901

Wilhelm et al., 1996

Aerobic Aquatic metabolism:	31.42 Days**	EFED Guideline

Anaerobic Aquatic metabolism: for entire sediment/water system	0.05 Days
MRID 43759301

Aqueous Photolysis	1.3 Day	MRID#s 42900201

Soil Water Partition Coefficient	 36.05 L Kg-1 	EPISUITE

Pesticide is Wetted-In	No	Product Label

Crop Management

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

Fumigation  Date for Florida and California 

Fumigation  Date for North Carolina 

	September 15

April 15	USDA

Application Method	Ground Application

(CAM 8)***	Standard assumption    

Application Efficiency	100%	Standard assumption     

* 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. December 4, 2001.

**  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

*** = 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. PRZM also
has limited capabilities in capturing the partitions of volatile
chemical in air, water and sediment.  Therefore, the estimated
concentrations of chloropicrin in water bodies may be upper bound since
the load of chloropicrin from runoff is considered in the PRZM/EXAMS
simulation.	

Table 8: Estimated Environmental Concentrations* (EECs) of Chloropicrin
in surface  water for selected crop scenarios

Crops	Application rate frequency	Acute: Peak 

EEC

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	3.66	1.42	0.61

California 

Onion	350 lbs a.i./A

1X Per Season	2.14	0.61	0.24

Florida 

Tomato	350 lbs a.i./Acre

1X Per Season	107.8	30.7	12.48

Florida Strawberry	350 lbs a.i./Acre

1X Per Season	59.75	17.65	6.69

North Carolina

Sweet Potato	350 lbs a.i./Acre

1X Per Season	1.67	0.48	0.18

North Carolina

Tobacco	350 lbs a.i./Acre

1X Per Season	1.45	0.46	0.18

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 \l4 "b.  Aquatic
Exposure Monitoring and Field Data 

	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 \l2 "C.  Ecological Effects
Characterization 	

	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 \l3 "1.  Aquatic Effects
Characterization 

			a.  Aquatic Animals  TC \l4 "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.  TC \f 1 "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	48/96 hours	LC50 < 16.98 ppb

(very highly toxic)	FTLR 425

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

	The acute toxicity of chloropicrin to freshwater fish was evaluated in
rainbow trout and bluegill sunfish, with LC50s of < 16.98 ppb (very
highly toxic) and < 105 ppb (at least highly toxic), respectively.  The
values are expressed as “less than” the numeric value, since
chloropicrin is highly volatile and measured residues were not provided.
 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

	

	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 \l3 "2.  Terrestrial
Effects Characterization 

			a.  Terrestrial Animals  TC \l4 "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.  TC \f 1 "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 \l1 "

IV.  Risk Characterization 

	A.  Risk Estimation - Integration of Exposure and Effects Data  TC \l2
"A.  Risk Estimation - Integration of Exposure and Effects Data 

	

			1.  Non-target Aquatic Animals and Plants  TC \l3 "1.  Non-target
Aquatic Animals and Plants 

	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. 

	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	3.66	<16.98	>0.22**

California onion	2.14	<16.98	>0.12**

Florida tomato	107.80	<16.98	>6.35***

Florida strawberry	59.75	<16.98	>3.52***

North Carolina sweet potato	1.67	<16.98	>0.10**

North Carolina tobacco	1.45	<16.98	>0.09*

Freshwater Aquatic Invertebrates

Acute risk4

California tomato	3.66	<71	>0.05*

California onion	2.14	<71	>0.03

Florida tomato	107.80	<71	>1.52***

Florida strawberry	59.75	<71	>0.84***

North Carolina sweet potato	1.67	<71	>0.02

North Carolina tobacco	1.45	<71	>0.02

*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 and Invertebrates

	As shown by the asterisks in the table above, all six of the scenarios
exceed at least one acute LOC, for fish and/or aquatic invertebrates
(based just on the numeric portion of the risk quotients shown).  Given
that all risk quotients are expressed as “greater than” these
numeric values, all scenarios for both taxonomic groups could
potentially exceed LOCs.   Whether or not they do will depend on future
resolution of definitive toxicity values.

	Specifically, for freshwater fish, risk quotients exceed a) the
endangered species acute LOC (0.05) for all six scenarios, b) the
restricted use LOC (0.1) for all scenarios except North Carolina
tobacco, and c)  the acute risk LOC (0.5) for Florida tomatoes and
Florida strawberries.  For aquatic invertebrates, risk quotients exceed
a) the endangered species acute LOC (0.05) for California tomatoes,
Florida tomatoes, and Florida strawberries, and b) the restricted use
LOC (0.1) and the acute risk LOC (0.5) for Florida tomatoes and Florida
strawberries. 

		2.  Non-target Terrestrial Animals  TC \l3 "2.  Non-target Terrestrial
Animals 

	

			a. Risk to Mammals  TC \l4 "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  TC \l4 "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 \l3 "3. 
Non-target Terrestrial and Semi-aquatic Plants 

	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 \l2 "B.  Risk Description 

		1.  Risk to Aquatic Organisms  TC \l3 "1.  Risk to Aquatic Organisms 

			A.  Animals  TC \l4 "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, risk quotients are
considered to exceed a) the endangered species acute LOC (0.05) for all
six scenarios, b) the restricted use LOC (0.1) for all scenarios except
North Carolina tobacco, and c)  the acute risk LOC (0.5) for Florida
tomatoes and Florida strawberries.  For aquatic invertebrates, risk
quotients are considered to exceed a) the endangered species acute LOC
(0.05) for California tomatoes, Florida tomatoes, and Florida
strawberries, and b) the restricted use LOC (0.1) and the acute risk LOC
(0.5) for Florida tomatoes and Florida strawberries.  In these cases,
the LOCs are exceeded based just on the numeric value of the risk
quotients.  As explained earlier, given that all risk quotients are
expressed as “greater than” these numeric values, all scenarios for
both taxonomic groups could potentially exceed LOCs.   Whether or not
they do will depend on future resolution of definitive toxicity values. 
 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. Thus, it cannot be determined that any use site
does not exceed acute LOCs.  However, in addition to the uncertainty
concerning the toxicity of chloropicrin to aquatic animals (i.e.,
chloropicrin is apparently more toxic than indicated in the studies),
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  TC \l4 "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 \l3 "2.  Risk to Terrestrial
Organisms 

			A.  Animals  TC \l4 "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 1,897, 813, and 28, 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 off-site monitoring
data, 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 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.

			B.  Plants  TC \l4 "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 \l3 "3.  Review of Incident Data 

	

	Extremely 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 is expected to assign 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.  The
California Pesticide Investigations Unit is checking further as to how
the pesticide moved to the stream.  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). 

   

	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).   These incidents help confirm the EFED assumption that
chloropicrin has the potential to adversely affect non-target plants.  

		4.  Endocrine Disruption  TC \l3 "4.  Endocrine Disruption 

	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
\l3 "5.  Federally Threatened and Endangered (Listed) Species Concerns  

		A.  Action Area  TC \l4 "A.  Action Area 

	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 is 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 \l4 "B. Taxonomic Groups
Potentially at Risk 

	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 \l5 "1.  Discussion of Risk
Quotients 

	Endangered Species LOCs are exceeded for wild mammals, fish, and
aquatic invertebrates based on acute risk quotients.  Although guideline
avian toxicity data are not available, birds may be as sensitive as
mammals.  The aquatic risk quotients are all 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 >), EFED cannot confirm that any site
definitely does not exceed a fish or aquatic invertebrate LOC. 
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 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 \l5 "2.  Probit Dose
Response Relationship 

	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 0.14, based on 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.

	Data are not adequate to calculate individual effect probabilities for
freshwater fish and aquatic invertebrates.  This is due to a lack of
measured concentrations in the fish studies 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 \l4 "C.  Data Related
to Under-represented Taxa 

	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 \l4 "D.  Implications of
Sublethal Effects 

	 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 \l4 "E.  Indirect Effects Analysis

	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 \l4 "F.  Critical Habitat 

	 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 \l4 "G.  Co-occurrence Analysis 				

	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 \l1 "V. Literature Cited 

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
Manual and system documentation. National Exposure Research Laboratory. 
U.S. Environmental Protection Agency, Research Trianglr Park, NC 27711. 
  HYPERLINK http://www.epa.gov/ceampubl/swater/exams/index.htm
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.

MRID# 43022401. Chang, T. 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,
Inc., Richmond, CA; and submitted by Chloropicrin Manufacturers Task
Force, c/o Niklor Chemical Company, Long Beach, CA.

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
Project No.:  587W.  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. 

NASS (National Agricultural Statistics Service) 2005. Year 2002 Usage
statistics for chloropicrin   HYPERLINK
http://www.pestmanagement.info/nass/
http://www.pestmanagement.info/nass/ 

Pe4 Shell.  2004.  Environmental Fate and Effects Division, Office of
Pesticide Programs, U.S. Environmental Protection Agency, Washington,
D.C.  Information downloaded from the website   HYPERLINK
http://www.epa.gov/oppefed1/models/water/
http://www.epa.gov/oppefed1/models/water/  

Sadtler Research Laboratories.1980. Standard Spectra Collection. Sadtler
Research Laboratories Division of Bio-Rad Laboratories, Inc.
Philadelphia, Pa.

Scheer, V., A. Frenzel, W. Behnke, C. Zetzsch, L. Magi, Ch. George, and
Ph. Mirabel. 1997.Uptake of Nitrosyl Chloride (NOCL) by Aqueous
Solutions. J. Phys. Chem. 101:9359 - 9366.

Selala, M., et. al.  1989.  An improperly labeled container with
chloropicrin: A farmer’s nightmare.  Bull. Environ. Contam. Toxicol.
42: 202-208. 

Singh H.B. 1976. Phosgene in the ambient air. Nature. 264:428-429.

Shorter, J.H., C.E. Kolb, and P.M. Crill. 1995. Rapid Degradation of
Atmospheric Methylbromide in Soils. Nature. 377:717-719.

UNIDO. 2003. Ozone-friendly Industrial Development UNIDO in the Montreal
Protocol - technology transfer to other countries. Impact and lessons
learned - Fumigants. United Nations Industrial Development Organization,
Vienna, Austria. 21 pp.

U.S. EPA (United States Environmental Protection Agency).1992. Pesticide
in ground water data base. A compilation of monitoring studies:
1971-1991. A National summary. p. NS-163 (1992)

U.S. EPA. (United States Environmental Protection Agency). 1995.
User’s Guide for the Industrial Source complex Dispersion Models.
Volume 1. User Instructions. USEPA Office of Air Quality Planning and
Standards; Emissions, Monitoring and Analysis Division, Research
Triangle Park, North Carolina.

USEPA.  1998a.  Guidelines for Ecological Risk Assessment. Published on
May 14, 1998, Federal Register 63(93):26846-26924. Risk Assessment
Forum, U.S. Environmental Protection Agency, Washington, D.C.
EPA/630/R-95/002F. 191 pgs. April.

USEPA (U.S. Environmental Protection Agency). 2002. Inventory of U.S.
Greenhouse Gas Emissions and Sinks: 1990-2000. U.S. Environmental
Protection Agency, Office of Atmospheric Programs, EPA 430-R-02_003.

U.S. EPA (United States Environmental Protection Agency). 2004. Health
Effects Division’s Draft Standard Operating Procedures (SOPs) for
Estimating Bystander Risk from Inhalation Exposure to Soil Fumigant.

USEPA (U.S. Environmental Protection Agency). 2005a. Overview of the Use
and Usage of Soil Fumigants. Biological and Economic Analysis Division.
U.S. Environmental Protection Agency, Office of Pesticide Programs.
www.epa.gov/oppsrrd1/reregistration/soil_fumigants/soil_fumigant_use.pdf

USEPA (U.S. Environmental Protection Agency). 2005b. Environmental Fate
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Bromide. U.S. Environmental Protection Agency Office of Pesticide
Programs, Washington, D.C.

USEPA (U.S. Environmental Protection Agency). 2005c. Human Health Risk
Assessment: Chloropicrin. U.S. Environmental Protection Agency, Office
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Wilhelm, S.N., K. Shepler, L.J. Lawrence, and H. Lee. 1996.
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Fumigants: Environmental fate, exposure, and analysis. ACS Symp. Ser.
652. American Chemical Society, Washington, DC. 

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Lifetime of Atmospheric CH3Br. Geophysical Res. Lett. 23:53-56.

VI. Appendices  TC \l1 "VI. Appendices 

	Appendix A.  Environmental Fate and Transport Data  TC \l2 "Appendix A.
 Environmental Fate and Transport Data 

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 25̊C.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)

This study provides very limited supplemental information.  A new study
is required. However, the study provides some information about the
nature of the photolysis products of chloropicrin.  Major problems were
found in this study related to the material balance.

Chloropicrin, at 164 mg/L, photodegraded with a registrant-calculated
half-life of 31.1 hours (1.29 days) in sterile aqueous solutions
buffered at pH 7 at 25̊C, irradiated with a xenon arc lamp (at about
twice the intensity of natural sunlight in April in Hollister,
California) on a 12 hour photoperiod.  In contrast, the dark controls
did not appear to hydrolyze substantially during the test period.

                           hv

CCl3NO2    --------------------->    3Cl-     +     NO2-      +     
NO3-       +        CO2         +        H+

                           H2O                                          
                                   (HCO3- + CO22-)

    

Chloride increased to up to 0.00240 M (80%) after 108 hours.  CO2
increased to up to 0.000143 M (14.3%) after 108 hours.  The bicarbonate
ion increased to 0.000573 M after 108 hours.  Other products were
nitrate and nitrite, at maximum of 0.000347 M and 0.000143 M, at 108
hours, respectively.  The chloride ion reached 0.00205 M after 108
hours.

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)

The 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)

This aerobic soil metabolism study is scientifically valid and provides
useful information on the aerobic soil metabolism of chloropicrin.  The
study is acceptable as it followed the previously approved protocol for
the data requirement.  No new study is required.The  registrant is
required to address the following problems found in the study:

	Maintenance of aerobic conditions and moisture at the water holding
capacity (WHC) throughout the experiment;

	Effects of chloropicrin on soil viability;

	Location of the PUF trap in relation to the KOH trap; and

	The target thickness, in inches, of the soil to be treated in th field
and its vertical location in the soil profile.

[14C]chloropicrin, at nominal application rates of 310-329 ppm, or
equivalent field rates of nearly 550-600 lb a.i/acre, degraded in the
laboratory with calculated half-life of 8 to 11 days in Baywood sandy
loam soil adjusted to 78% of 0.33 bar moisture and incubated in the dark
at 25±1oC for up to 21 and 24 days.

The study was performed using three samples sets which were not treated
at the same rate or incubated simultaneously.  The study indicates that
biotic transformation into CO2 is the most important process that had
governed the fate of chloropicrin under the stated laboratory
conditions. Initially, parent escaped biodegradation by volatilization
but later was subject to biodegradation and to binding, into the soil,
in a non-extractable form.

Evolved 14CO2 increased to 72.2% at 24 days posttreatment. 
Chloronitromethane, nitromethane, and bicarbonate were the only three
minor degradates identified (a total of <6% of the applied
radioactivity).  Degradates were formed by substitution of Cl by H and
were mainly detected in association with the soil in extractable and
later in nonextractable forms.

This aerobic soil study was conducted without supplying the system with
continuous flow to remove volatile materials. This type of system do not
closely mimic field condition where volatilized materials are relatively
free to escape.

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.

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

This study provides useful supplemental information about the anaerobic
aquatic metabolism of chloropicrin.  The study does not meet Subdivision
N Guidelines for the fulfillment of EPA data requirements for the
following reasons:

	The test water was not representative of that found at an intended use
site (purified deionized water was utilized to flood the soil samples). 

	The analytical methods were inadequate for the characterization of
residues in water samples removed at later sampling intervals.  The HPLC
column recoveries for the water phase samples were 103-104% at 0-1.5
hours posttreatment, decreased to 83.6% by 5 days posttreatment, and
were 24.1% at 54 days posttreatment.  The study authors did not provide
an explanation for this decrease.  

Radiolabeled [14C]chloropicrin, at a nominal application rate of 313 ±
14.4 µg/g, degraded with a calculated half-life of 1.3 hours (r2 = 1.0;
0- to 4-hour data only) in anaerobic flooded sandy loam soil that was
incubated in darkness at 25 ± 1̊C for up to 54 days.

All data are reported as percentages of the nominal application. 
Degradate data are reported in parent equivalents.  The parent was
initially present in the total soil/water system at 96.3% of the applied
radioactivity, decreased to 45.5% by 1.5 hours and 11.2% by 4 hours, was
1.7-2.2% at 1-2 days, was not detected from 5 to 12 days, and was last
detected at 0.1% (one of two replicates) at 26 days posttreatment.  The
parent was mostly associated with the water phase.

The major degradate nitromethane was a maximum of 53.4% at 1 day, and
was last detected at 16.9% (one of two replicates) at 26 days
posttreatment.

The major degradate chloronitromethane increased to 51.5% by 4 hours,
and was last detected at 0.1% (one of two replicates) at 54 days
posttreatment.

Nonextractable [14C]residues increased to a maximum of 32.0% at 54 days
posttreatment; [14C]residues associated with the fulvic and humic acid
fractions were 24.4% and 1.3% of the applied, respectively, at 54 days
posttreatment.

[14C]Volatiles in the KOH traps reached 45.7% at 54 days posttreatment. 
Based on BaCl2 precipitation of KOH traps, evolved 14CO2 accounted for
4.1% at 54 days posttreatment.

[14C]Organic volatiles were a maximum of 8.8% of the applied
radioactivity at 1.5 hours, were 2.5-4.9% at 1-5 days, and were 0.6% at
54 days posttreatment.  Based on HPLC analysis of the foam plug extract,
the parent accounted for 8.1% of the applied radioactivity at 1.5 hours
and was 1.1-1.8% at 1-2 days posttreatment.  Radioactivity in the
headspace was 10.9% of the applied radioactivity at 1.5 hours and was
0.1-0.7% at 1-54 days posttreatment; the parent accounted for 10.7% of
the applied at 1.5 hours posttreatment.

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

This study is considered acceptable and it meets Subdivision §N
Guidelines for the fulfillment of the mobility data requirement (column
leaching) of chloropicrin.  However, data were variable for the silty
clay loam soil and the loamy sand soil, precluding definitive mobility
determinations for the compound in those soils.

The column leaching of [14C]chloropicrin, at a nominal rate equivalent
to 345 lb/A or 362 lb/A was studied in sandy loam, loamy sand, silt
loam, and silty clay loam soil columns which were leached with CaCl2
over a period of 17-138 hours, 1-1.5 hours, 126-132 hours, and 101-116
hours, respectively.  Based on the results of this study, it was
observed that chloropicrin is very mobile in all four soils tested.

In the Baywood sandy loam soil, most of the [14C]residues retained in
the soil column following leaching were detected in the 30- to 36-cm
(4.6%), 36- to 42-cm (5.7%), and 42- to 48-cm (5.7%) depths.  The parent
was 4.0% of the applied radioactivity in the 12- to 24-cm depth (12- to
18-cm and 18- to 24-cm depths combined), was 6.9% in the 24- to 36-cm
depth (24- to 30-cm and 30- to 36-cm depths combined), and was 11.2% in
the 36- to 48-cm depth (36- to 42-cm and 42- to 48-cm depths combined). 
The minor degradates dichloronitromethane, and nitromethane were
detected once each.  Nonextractable [14C]residues were 1.0% of the
applied radioactivity in the 12- to 18-cm depth, and were 0.4-0.5% in
each of the 18- to 24-cm, 30- to 36-cm, 36- to 42-cm, 24- to 30-cm, and
42- to 48-cm depths.  Total [14C]residues in the leachate solution were
30.8% of the applied radioactivity.  The parent was 17.2% of that
radioactivity; the minor degradates dichloromethylhydroxylamine,
dichloronitromethane, and nitromethane were ≤7.3% of the applied
radioactivity.  [14C]Organic volatiles (bottom of the column) were 32.8%
of the applied radioactivity; the parent accounted for 32.4% of the
applied. 

In the Baywood loamy sand soil, most of the [14C]residues retained in
the soil column following leaching were detected in the 12- to 18-cm
(22.6%) depth.  The parent was 36.6% (two of three columns) of the
applied radioactivity in the 12- to 24-cm depth (12- to 18-cm and 18- to
24-cm depths combined) and was 8.6% (two of three columns) in the 24- to
48-cm depth (24- to 30-cm, 30- to 36-cm, 36- to 42-cm, and 42- to 48-cm
depths combined).  Degradates were not detected.  Nonextractable
[14C]residues were 0.1% of the applied radioactivity in each of the 18-
to 24-cm, 24- to 30-cm, 30- to 36-cm, 36- to 42-cm, and 42- to 48-cm
depths. Total [14C]residues in the leachate solution were 43.7% of the
applied radioactivity.  The parent was 42.7% of the applied
radioactivity.  The minor degradates dichloronitromethane and
dichloromethyl hydroxylamine were each ≤0.77% of the applied
radioactivity.  [14C]Organic volatiles (bottom of the column) were 12.2%
of the applied radioactivity; the parent accounted for 12.2% of the
applied. 

In the Congaree silt loam soil, most of the [14C]residues retained in
the soil column following leaching were detected in the 36- to 42-cm
(6.6%) and 42- to 48-cm (6.9%) depths.  The parent was 0.1% of the
applied radioactivity in each of the 12- to 30-cm (combined), 30- to
42-cm (combined), and 42- to 48-cm depths.  The minor degradates
dichloromethylhydroxylamine, dichloronitromethane, and nitromethane were
detected at ≤0.1% of the applied radioactivity.  Nonextractable
[14C]residues were 0.4% of the applied radioactivity in the 6- to 12-cm
depth, were 2.5-4.5% in each of the 12- to 18-cm, 18- to 24-cm, and 24-
to 30-cm depth, and were 5.0-5.7% in each of the 30- to 36-cm, 36- to
42-cm, and 42- to 48-cm depths; [14C]residues associated with the 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, in
each of the 12- to 18-cm, 18- to 24-cm, 24- to 30-cm, 30- to 36-cm, 36-
to 42-cm, and 42- to 48-cm depths.  Total [14C]residues in the leachate
solution were 31.6% of the applied radioactivity.  The parent was 1.1%
of the applied radioactivity.  The major degradate
dichloromethylhydroxylamine was 16.4% of the applied radioactivity.  The
major degradate dichloronitromethane was 10.9% of the applied
radioactivity.  The minor degradate nitromethane was 2.5% of the applied
radioactivity.  [14C]Organic volatiles (bottom of column) were 17.8% of
the applied radioactivity; the parent and dichloronitromethane accounted
for 13.8% and 3.3% of the applied, respectively. 

In the Lowell silty clay loam soil, most of the [14C]residues retained
in the soil column following leaching were detected in the 12- to 18-cm
(24.3%) depth.  Characterization data were variable between the two soil
columns.  In Column 1, the parent was 0.1% of the applied radioactivity
in each of the 12- to 30-cm, 30- to 42-cm, and 42- to 48-cm depths.  In
Column 2, the parent was 49.3% of the applied radioactivity in the 12-
to 24-cm depth, was 1.3% in the 24- to 36-cm depth, and was not detected
in the 36- to 48-cm depth.  The minor degradates dichloronitromethane,
and dichloromethylhydroxylamine were ≤1.5% of the applied
radioactivity.  Nonextractable [14C]residues were ≤2.2% of the applied
radioactivity in each of the soil depth from 6- to 42-cm; [14C]residues
associated with the humic acid, fulvic acid, and humin fractions of
combined soil columns (12 to 48-cm depth) were 0.5%, 6.3%, and 6.0% of
the applied, respectively. Total [14C]residues in the leachate solution
were 20.5% of the applied radioactivity.  The parent compound was
present at 1.5% (one of two column leachates) of the applied
radioactivity.  The major degradate dichloronitromethane was 12.0% of
the applied radioactivity.  The minor degradates
dichloromethylhydroxylamine, and nitromethane were ≤5.5% of the
applied radioactivity.  [14C]Organic volatiles (bottom of column) were
19.4% of the applied radioactivity; the parent accounted for 14.5% (one
of two columns) of the applied.  The major degradate
dichloronitromethane was detected at 10.3% of the applied radioactivity.
 The minor degradate nitromethane was 1.5% of the applied radioactivity.
 The minor degradate dichloromethyl-hydroxylamine was 0.6% of the
applied radioactivity. 

163-2 Laboratory Volatility (MRID# 43798601)

This study is acceptable as it meets Subdivision N Guidelines for the
fulfillment of EPA data requirements on laboratory volatility.  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.

The registrant is required to address the following:

	Time zero analysis of treated soil was not conducted;

	Was the trapping efficiencies of charcoal, methanol, and KOH traps
determined? if so give the results.

	Need to relate the 100 mL/min flow rate or corresponding air changes/hr
to total exchanges during actual practice under greenhouse, and field
conditions (specified wind speeds).

	Limits of detection were reported but limits of quantitation were not;

	What is the vapor pressure at 25 oC? Other references give 23.8 mm Hg;
Is this accurate?

Although [14C]chloropicrin was applied through sub-surface injection, it
volatilized within few to nearly 30 hours from non-tarped and tarped
soil surfaces, respectively. By the end of the 8-day laboratory
experiment, 80-87% of the applied parent volatilized from the soil
surface as parent, 5-8% volatilized as CO2, 5-7% bound to the soil, and
<1% degraded into chloronitromethane. The results indicate that
volatilization as parent, is expected to be the most important route of
dissipation for chloropicrin in the soil environment. Data on non-tarped
and tarped covered soil surfaces indicate that covering the soil surface
with plastic tarp caused a change in the pattern and rates of
volatilization during the first 60 hours of the experiment. 

[14C]chloropicrin, at a nominal application rate of 300 ppm, volatilized
from sandy loam soil (uncovered and tarp-covered) adjusted to 60% of
0.33 bar soil moisture content and incubated in darkness at 25.0 ± 1̊C
for up to 8 days with an air flow (>90% relative humidity) rate of
approximately 100 mL/min.  

In the uncovered (no tarp) soil, the maximum volatility of the parent
was 342 µg/cm2/hr and the maximum air concentration of the parent was
1.0 × 104 µg × 103/m3 (2-6 hour interval).  Total [14C]volatiles
accounted for 92.6% of the applied radioactivity at 8 days
posttreatment.  Organic [14C]volatiles detected in the methanol, water
vapor, and charcoal traps were 86.0%, 1.5%, and 0.08% of the applied
radioactivity, respectively, at 8 days posttreatment; evolved 14CO2 was
5.1% of the applied.  The parent was initially (2 hours) present in the
methanol trap at 0.8% of the applied radioactivity, increased to 16.3%
by 6 hours and 65.4% by 24 hours, and was 81.5-85.5% at 46-116 hours
posttreatment.  The degradate dichloronitromethane was detected in the
methanol trap at 0.4% of the applied radioactivity.  In the soil,
extractable and nonextractable [14C]residues were 0.4% and 4.3% of the
applied radioactivity, respectively, at 8 days posttreatment.

In tarp covered soil, the pesticide stayed within the soil system for
relatively longer period of time than in non-tarped soil. This resulted
in a slightly higher pesticide bio-degradation and binding to the tarped
compared to non-tarped soil as inferred from the observed higher
concentrations of  CO2 and soil bound residue.  In the tarp-covered
soil, the maximum volatility of the parent was 205 µg/cm2/hr and the
maximum air concentration of the parent was 5918 µg × 103/m3 (23-25
hour interval; interval in which the tarp was punctured).  Total
[14C]volatiles accounted for 89.3% of the applied radioactivity at 8
days posttreatment.  Organic [14C]volatiles detected in the methanol,
water vapor, and charcoal traps were 79.9%, 1.2%, and 0.09% of the
applied radioactivity, respectively, at 8 days posttreatment; evolved
14CO2 was 8.2% of the applied.  The parent was initially (4 hours)
present in the methanol trap at 1.9% of the applied radioactivity,
increased to 38.7% by 23 hours and 67.2% by 47 hours, and was 79.1% at
144 hours posttreatment.  The degradate dichloronitromethane was
detected in the methanol trap at 0.7% of the applied radioactivity.  In
the soil, extractable and nonextractable [14C]residues were 1.1% and
6.1% of the applied radioactivity, respectively, at 8 days
posttreatment.  

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

This study provides limited supplemental information about the
terrestrial field dissipation of chloropicrin.  Several problems were
found in the study:

	samples were taken only of the soil air and analyzed only for
chloropicrin (and methyl bromide), no soil samples were taken;

	the test soils were not completely characterized;

	the site description was incomplete and not adequately characterized;

	the field maintenance practices used before and after application were
not provided.

Chloropicrin dissipated with half-lives of 11.6, 16.4, and 33.4 hours
from the soil air at the 3-, 6-, and 12-inch depths, respectively,
following treatment with 665 lb a.i./A chloropicrin (TRI-CLOR: 99%
purity) of a tarped clay loam soil in California in July, 1987.  The
chloropicrin was applied by chisel injection at a depth of 6-8 inches,
the soil surface was covered with a polyethylene tarp for 48 hours, and
sampling was initiated after removal of the tarp.  Chloropicrin was
found at maximum concentration of 755-781 ppm in the soil air from the
upper 12 inches at 51 hours posttreatment (3 hours after removal of the
tarp). Concentrations at the 24-, 36-, and 48-inch depths were never
exceeded 30, 8.6, and 5.8 ppm, respectively, and declined to below
background levels by the termination of the study (291 hours
posttreatment).  Background levels of chloropicrin (as determined by
analysis of soil air from the untreated check plot located 15 feet away
from the treated plot) ranged from 0.2 to 8.5 ppm (average 2.9 ppm).

Chloropicrin dissipated with half-lives of 18.0, 20.3, and 28.7 hours
from the soil air at the 3-, 6-, and 12-inch depths, respectively,
following treatment with 792 lb a.i./A chloropicrin (TRI-CLOR: 99%
purity) of a tarped sand soil in California in August, 1987.  The
chloropicrin was applied by chisel injection at a depth of 6-8 inches,
the soil surface was covered with a polyethylene tarp for 48 hours, and
sampling was initiated after removal of the tarp.  Chloropicrin was
found at maximum concentrations of 554.0, 930.0, and 1185.0 ppm in the
3-, 6-, and 12-inch soil depths, respectively, at 51 hours posttreatment
(3 hours after removal of the tarp). Concentrations 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, 12, and 48 hours,
respectively, after removal of the tarp.  By the termination of the
study (240 hours posttreatment), concentrations at 24-, 36-, and 48-inch
depths had decreased to 31.8, 37.1, and 16.8 ppm, respectively. 
Background levels of chloropicrin (as determined by analysis of soil air
from the untreated check plot located 15 feet away from the treated
plot) ranged from 0.3 to 8.5 ppm (average 1.9 ppm).



	Appendix B. Aquatic Exposure PRZM/EXAMS Modeling  TC \l2 "Appendix B.
Aquatic Exposure PRZM/EXAMS Modeling 

	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 FLStrawb.out

Chemical: Chloropicrin

PRZM environment: FlstrawberryC.txt, Modified Monday, 30 June 2003 at
08:19:10

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

Metfile: w12842.dvf, Modified Wedday, 3 July 2002 at 09:04:28

Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	4.62	3.11	1.38	0.57	0.39	0.10

1962	84.41	57.97	21.99	8.16	5.45	1.34

1963	33.19	22.05	8.17	3.42	2.30	0.57

1964	3.16	2.18	1.15	0.53	0.36	0.09

1965	104.00	69.55	26.30	9.81	6.55	1.62

1966	5.05	3.58	2.12	0.91	0.61	0.15

1967	6.91	4.70	2.87	1.18	0.79	0.20

1968	8.70	5.98	2.72	1.19	0.81	0.20

1969	12.37	8.54	3.85	1.59	1.09	0.27

1970	9.06	6.21	2.81	1.18	0.80	0.20

1971	6.26	4.40	2.64	1.05	0.71	0.17

1972	8.03	6.09	2.53	1.24	0.83	0.20

1973	12.09	8.28	4.75	2.08	1.40	0.35

1974	6.28	4.33	2.06	0.84	0.56	0.14

1975	14.37	9.83	4.59	1.98	1.33	0.33

1976	9.72	6.82	3.89	1.91	1.29	0.32

1977	60.94	44.11	17.73	6.73	4.49	1.11

1978	9.81	6.99	4.60	1.86	1.24	0.31

1979	16.43	13.15	6.33	2.49	1.67	0.41

1980	8.42	6.11	2.81	1.14	0.77	0.19

1981	24.23	18.26	8.82	3.67	2.46	0.61

1982	49.07	36.61	16.95	6.34	4.23	1.04

1983	8.85	6.38	3.01	1.46	0.98	0.24

1984	3.25	2.25	1.53	0.67	0.45	0.11

1985	5.84	4.05	2.61	1.41	0.95	0.23

1986	12.51	9.87	4.56	1.74	1.17	0.29

1987	5.41	3.94	1.83	0.75	0.50	0.12

1988	9.87	6.79	3.38	1.69	1.14	0.28

1989	10.91	7.70	3.38	1.55	1.05	0.26

1990	3.08	2.24	1.32	0.50	0.33	0.08

Sorted results

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

0.03	104.00	69.55	26.30	9.81	6.55	1.62

0.06	84.41	57.97	21.99	8.16	5.45	1.34

0.10	60.94	44.11	17.73	6.73	4.49	1.11

0.13	49.07	36.61	16.95	6.34	4.23	1.04

0.16	33.19	22.05	8.82	3.67	2.46	0.61

0.19	24.23	18.26	8.17	3.42	2.30	0.57

0.23	16.43	13.15	6.33	2.49	1.67	0.41

0.26	14.37	9.87	4.75	2.08	1.40	0.35

0.29	12.51	9.83	4.60	1.98	1.33	0.33

0.32	12.37	8.54	4.59	1.91	1.29	0.32

0.35	12.09	8.28	4.56	1.86	1.24	0.31

0.39	10.91	7.70	3.89	1.74	1.17	0.29

0.42	9.87	6.99	3.85	1.69	1.14	0.28

0.45	9.81	6.82	3.38	1.59	1.09	0.27

0.48	9.72	6.79	3.38	1.55	1.05	0.26

0.52	9.06	6.38	3.01	1.46	0.98	0.24

0.55	8.85	6.21	2.87	1.41	0.95	0.23

0.58	8.70	6.11	2.81	1.24	0.83	0.20

0.61	8.42	6.09	2.81	1.19	0.81	0.20

0.65	8.03	5.98	2.72	1.18	0.80	0.20

0.68	6.91	4.70	2.64	1.18	0.79	0.20

0.71	6.28	4.40	2.61	1.14	0.77	0.19

0.74	6.26	4.33	2.53	1.05	0.71	0.17

0.77	5.84	4.05	2.12	0.91	0.61	0.15

0.81	5.41	3.94	2.06	0.84	0.56	0.14

0.84	5.05	3.58	1.83	0.75	0.50	0.12

0.87	4.62	3.11	1.53	0.67	0.45	0.11

0.90	3.25	2.25	1.38	0.57	0.39	0.10

0.94	3.16	2.24	1.32	0.53	0.36	0.09

0.97	3.08	2.18	1.15	0.50	0.33	0.08

0.10	59.75	43.36	17.65	6.69	4.47	1.10

Average of yearly averages:	0.38

Inputs generated by pe4.pl - 8-August-2003

Data used for this run:

Output File: FLStrawb

Metfile:	w12842.dvf

PRZM scenario:	FLstrawberryC.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	31.42	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.05	days	Halfife

Aerobic Soil Metabolism	asm	15.71	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	15-9	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	Pond

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

B.1.2 Florida Tomato

stored as FLTomato.out

Chemical: Chloropicrin

PRZM environment: FltomatoC.txt, Mmodified Satday, 12 October 2002 at
16:44:04

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

Metfile: w12844.dvf, Modified Wedday, 3 July 2002 at 09:04:30

	Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	1.97	1.31	0.69	0.45	0.30	0.07

1962	106.00	79.75	29.59	10.54	7.03	1.73

1963	77.19	53.35	30.82	12.70	8.47	2.09

1964	56.35	38.79	19.41	7.97	5.33	1.31

1965	20.89	15.09	6.21	3.20	2.15	0.53

1966	24.46	17.68	7.92	3.41	2.27	0.56

1967	69.80	48.03	20.98	8.44	5.63	1.39

1968	55.26	44.23	24.24	9.56	6.37	1.57

1969	55.05	37.46	18.79	7.41	4.95	1.22

1970	31.83	21.15	9.60	3.46	2.31	0.57

1971	4.84	3.30	1.22	0.73	0.49	0.12

1972	1.49	1.03	0.36	0.13	0.09	0.02

1973	10.10	6.95	3.58	1.92	1.28	0.32

1974	21.65	12.56	6.02	2.28	1.53	0.38

1975	134.00	91.32	35.73	12.86	8.58	2.11

1976	4.26	2.83	1.16	0.69	0.47	0.11

1977	29.54	20.72	7.30	2.61	1.76	0.43

1978	12.72	8.86	3.67	1.58	1.06	0.26

1979	30.37	22.90	10.76	4.22	2.82	0.69

1980	13.06	8.86	2.94	1.29	0.87	0.21

1981	57.10	43.42	14.60	5.39	3.61	0.89

1982	20.74	14.47	6.84	2.64	1.76	0.43

1983	108.00	72.53	27.05	10.10	6.75	1.66

1984	64.45	46.78	21.74	7.87	5.29	1.30

1985	78.82	55.70	24.52	8.96	5.98	1.47

1986	4.07	2.68	0.84	0.55	0.38	0.10

1987	71.64	48.12	20.39	7.73	5.16	1.27

1988	4.06	2.68	0.85	0.32	0.21	0.05

1989	42.45	27.53	9.17	3.63	2.42	0.60

1990	198.00	132.00	46.46	16.59	11.06	2.73

Sorted results

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

0.03	198.00	132.00	46.46	16.59	11.06	2.73

0.06	134.00	91.32	35.73	12.86	8.58	2.11

0.10	108.00	79.75	30.82	12.70	8.47	2.09

0.13	106.00	72.53	29.59	10.54	7.03	1.73

0.16	78.82	55.70	27.05	10.10	6.75	1.66

0.19	77.19	53.35	24.52	9.56	6.37	1.57

0.23	71.64	48.12	24.24	8.96	5.98	1.47

0.26	69.80	48.03	21.74	8.44	5.63	1.39

0.29	64.45	46.78	20.98	7.97	5.33	1.31

0.32	57.10	44.23	20.39	7.87	5.29	1.30

0.35	56.35	43.42	19.41	7.73	5.16	1.27

0.39	55.26	38.79	18.79	7.41	4.95	1.22

0.42	55.05	37.46	14.60	5.39	3.61	0.89

0.45	42.45	27.53	10.76	4.22	2.82	0.69

0.48	31.83	22.90	9.60	3.63	2.42	0.60

0.52	30.37	21.15	9.17	3.46	2.31	0.57

0.55	29.54	20.72	7.92	3.41	2.27	0.56

0.58	24.46	17.68	7.30	3.20	2.15	0.53

0.61	21.65	15.09	6.84	2.64	1.76	0.43

0.65	20.89	14.47	6.21	2.61	1.76	0.43

0.68	20.74	12.56	6.02	2.28	1.53	0.38

0.71	13.06	8.86	3.67	1.92	1.28	0.32

0.74	12.72	8.86	3.58	1.58	1.06	0.26

0.77	10.10	6.95	2.94	1.29	0.87	0.21

0.81	4.84	3.30	1.22	0.73	0.49	0.12

0.84	4.26	2.83	1.16	0.69	0.47	0.11

0.87	4.07	2.68	0.85	0.55	0.38	0.10

0.90	4.06	2.68	0.84	0.45	0.30	0.07

0.94	1.97	1.31	0.69	0.32	0.21	0.05

0.97	1.49	1.03	0.36	0.13	0.09	0.02

0.10	107.80	79.03	30.70	12.48	8.33	2.05

	Average of yearly averages:	0.87

Inputs generated by pe4.pl - 8-August-2003

	Data used for this run:

	Output File: FLTomato

	Metfile:	w12844.dvf

PRZM scenario:	FLtomatoC.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

	31.42

	days

	Halfife

	

	

Anaerobic Aquatic Metabolism	kbacs	0.05	days	Halfife

Aerobic Soil Metabolism	asm	15.71	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	15-9	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	Pond

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

B.2.1 California Tomato

stored as CATomato.out

Chemical: Chloropicrin

PRZM environment: CAtomatoC.txt	Modified Wedday, 2 February 2005 at
12:45:10

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

Metfile: w93193.dvf, Modified Wedday, 3 July 2002 at 09:04:24

	Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.28	0.23	0.15	0.06	0.04	0.01

1962	0.44	0.34	0.15	0.05	0.04	0.01

1963	1.77	1.43	0.77	0.40	0.28	0.07

1964	2.50	1.90	0.91	0.36	0.24	0.06

1965	0.11	0.09	0.05	0.02	0.02	0.01

1966	0.52	0.46	0.27	0.13	0.09	0.02

1967	0.24	0.19	0.10	0.04	0.03	0.01

1968	2.23	1.75	0.85	0.49	0.34	0.09

1969	0.17	0.15	0.08	0.03	0.02	0.01

1970	0.28	0.22	0.13	0.06	0.04	0.01

1971	0.12	0.10	0.04	0.02	0.01	0.00

1972	0.50	0.42	0.26	0.11	0.07	0.02

1973	1.73	1.35	0.60	0.25	0.18	0.04

1974	6.62	5.11	2.42	1.00	0.67	0.17

1975	1.31	1.03	0.52	0.21	0.14	0.04

1976	4.19	3.30	1.48	0.63	0.43	0.11

1977	0.72	0.58	0.25	0.09	0.06	0.02

1978	0.25	0.21	0.10	0.05	0.03	0.01

1979	0.35	0.29	0.14	0.06	0.04	0.01

1980	0.02	0.02	0.01	0.00	0.00	0.00

1981	0.20	0.15	0.08	0.04	0.02	0.01

1982	3.79	2.93	1.87	0.84	0.61	0.16

1983	0.80	0.58	0.25	0.17	0.13	0.03

1984	0.68	0.54	0.27	0.16	0.13	0.03

1985	0.66	0.52	0.26	0.18	0.12	0.03

1986	0.14	0.12	0.05	0.02	0.01	0.01

1987	0.21	0.16	0.08	0.05	0.03	0.01

1988	0.13	0.11	0.06	0.03	0.02	0.01

1989	0.14	0.10	0.04	0.01	0.01	0.00

1990	0.07	0.05	0.03	0.02	0.01	0.00

Sorted results

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

0.03	6.62	5.11	2.42	1.00	0.67	0.17

0.06	4.19	3.30	1.87	0.84	0.61	0.16

0.10	3.79	2.93	1.48	0.63	0.43	0.11

0.13	2.50	1.90	0.91	0.49	0.34	0.09

0.16	2.23	1.75	0.85	0.40	0.28	0.07

0.19	1.77	1.43	0.77	0.36	0.24	0.06

0.23	1.73	1.35	0.60	0.25	0.18	0.04

0.26	1.31	1.03	0.52	0.21	0.14	0.04

0.29	0.80	0.58	0.27	0.18	0.13	0.03

0.32	0.72	0.58	0.27	0.17	0.13	0.03

0.35	0.68	0.54	0.26	0.16	0.12	0.03

0.39	0.66	0.52	0.26	0.13	0.09	0.02

0.42	0.52	0.46	0.25	0.11	0.07	0.02

0.45	0.50	0.42	0.25	0.09	0.06	0.02

0.48	0.44	0.34	0.15	0.06	0.04	0.01

0.52	0.35	0.29	0.15	0.06	0.04	0.01

0.55	0.28	0.23	0.14	0.06	0.04	0.01

0.58	0.28	0.22	0.13	0.05	0.04	0.01

0.61	0.25	0.21	0.10	0.05	0.03	0.01

0.65	0.24	0.19	0.10	0.05	0.03	0.01

0.68	0.21	0.16	0.08	0.04	0.03	0.01

0.71	0.20	0.15	0.08	0.04	0.02	0.01

0.74	0.17	0.15	0.08	0.03	0.02	0.01

0.77	0.14	0.12	0.06	0.03	0.02	0.01

0.81	0.14	0.11	0.05	0.02	0.02	0.01

0.84	0.13	0.10	0.05	0.02	0.01	0.01

0.87	0.12	0.10	0.04	0.02	0.01	0.00

0.90	0.11	0.09	0.04	0.02	0.01	0.00

0.94	0.07	0.05	0.03	0.01	0.01	0.00

0.97	0.02	0.02	0.01	0.00	0.00	0.00

0.10	3.66	2.83	1.42	0.61	0.42	0.10

	Average of yearly averages:	0.03

Inputs generated by pe4.pl - 8-August-2003

	Data used for this run:

	Output File: CATomato

	Metfile:	w93193.dvf

PRZM scenario:	CAtomatoC.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

	31.42

	days

	Halfife

	

	

Anaerobic Aquatic Metabolism	kbacs	0.05	days	Halfife

Aerobic Soil Metabolism	asm	15.71	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	15-9	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	Pond

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

B.2.2 California Onion

stored as CAOnion.out

	Chemical: Chloropicrin

PRZM environment: CAonionC.txt	Modified Monday, 23 December 2002 at
06:48:48

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

Metfile: w23155.dvf, Modified Wedday, 3 July 2002 at 09:04:20

	Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.02	0.02	0.01	0.00	0.00	0.00

1962	0.00	0.00	0.00	0.00	0.00	0.00

1963	15.87	11.74	4.63	1.73	1.15	0.28

1964	0.19	0.14	0.06	0.02	0.02	0.00

1965	0.06	0.05	0.02	0.01	0.01	0.00

1966	0.06	0.05	0.03	0.02	0.01	0.00

1967	0.10	0.09	0.05	0.02	0.02	0.00

1968	0.49	0.39	0.19	0.08	0.06	0.01

1969	0.04	0.03	0.01	0.00	0.00	0.00

1970	0.06	0.04	0.02	0.01	0.01	0.00

1971	0.01	0.00	0.00	0.00	0.00	0.00

1972	0.29	0.23	0.10	0.06	0.04	0.01

1973	0.01	0.01	0.01	0.00	0.00	0.00

1974	5.68	4.26	1.70	0.65	0.44	0.11

1975	0.01	0.00	0.00	0.00	0.00	0.00

1976	0.50	0.35	0.13	0.05	0.03	0.01

1977	0.03	0.02	0.00	0.00	0.00	0.00

1978	0.02	0.01	0.01	0.00	0.00	0.00

1979	0.00	0.00	0.00	0.00	0.00	0.00

1980	0.00	0.00	0.00	0.00	0.00	0.00

1981	1.94	1.48	0.61	0.23	0.15	0.04

1982	2.16	1.56	0.60	0.24	0.17	0.04

1983	0.09	0.07	0.03	0.02	0.01	0.00

1984	0.06	0.04	0.02	0.01	0.01	0.00

1985	0.35	0.28	0.13	0.06	0.04	0.01

1986	0.03	0.02	0.01	0.01	0.00	0.00

1987	1.44	1.15	0.53	0.20	0.14	0.03

1988	0.00	0.00	0.00	0.00	0.00	0.00

1989	1.09	0.68	0.20	0.07	0.05	0.01

1990	0.00	0.00	0.00	0.00	0.00	0.00

Sorted results

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

0.03	15.87	11.74	4.63	1.73	1.15	0.28

0.06	5.68	4.26	1.70	0.65	0.44	0.11

0.10	2.16	1.56	0.61	0.24	0.17	0.04

0.13	1.94	1.48	0.60	0.23	0.15	0.04

0.16	1.44	1.15	0.53	0.20	0.14	0.03

0.19	1.09	0.68	0.20	0.08	0.06	0.01

0.23	0.50	0.39	0.19	0.07	0.05	0.01

0.26	0.49	0.35	0.13	0.06	0.04	0.01

0.29	0.35	0.28	0.13	0.06	0.04	0.01

0.32	0.29	0.23	0.10	0.05	0.03	0.01

0.35	0.19	0.14	0.06	0.02	0.02	0.00

0.39	0.10	0.09	0.05	0.02	0.02	0.00

0.42	0.09	0.07	0.03	0.02	0.01	0.00

0.45	0.06	0.05	0.03	0.02	0.01	0.00

0.48	0.06	0.05	0.02	0.01	0.01	0.00

0.52	0.06	0.04	0.02	0.01	0.01	0.00

0.55	0.06	0.04	0.02	0.01	0.01	0.00

0.58	0.04	0.03	0.01	0.01	0.00	0.00

0.61	0.03	0.02	0.01	0.00	0.00	0.00

0.65	0.03	0.02	0.01	0.00	0.00	0.00

0.68	0.02	0.02	0.01	0.00	0.00	0.00

0.71	0.02	0.01	0.01	0.00	0.00	0.00

0.74	0.01	0.01	0.00	0.00	0.00	0.00

0.77	0.01	0.00	0.00	0.00	0.00	0.00

0.81	0.01	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	2.14	1.55	0.61	0.24	0.17	0.04

Average of yearly averages:	0.02

Inputs generated by pe4.pl - 8-August-2003

	Data used for this run:

	Output File: CAOnion

	Metfile:	w23155.dvf

PRZM scenario:	CAonionC.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	31.42	days	Halfife

Anaerobic Aquatic Metabolism	kbacs	0.05	days	Halfife

Aerobic Soil Metabolism	asm	15.71	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	15-9	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	Pond

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

B.3.1 North Carolina Tobacco

stored as NCTobac.out

Chemical: Chloropicrin

PRZM environment: NctobaccoC.txt, modified Satday, 12 October 2002 at
17:13:36

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

Metfile: w13722.dvf,modified Wedday, 3 July 2002 at 09:05:50

	Water segment concentrations (ppb)

Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	0.67	0.49	0.18	0.07	0.04	0.01

1962	0.03	0.02	0.01	0.01	0.00	0.00

1963	0.61	0.46	0.21	0.08	0.05	0.01

1964	0.02	0.01	0.00	0.00	0.00	0.00

1965	0.14	0.11	0.04	0.02	0.01	0.00

1966	0.91	0.67	0.26	0.11	0.07	0.02

1967	0.97	0.70	0.41	0.17	0.12	0.03

1968	0.08	0.06	0.02	0.01	0.01	0.00

1969	0.07	0.05	0.03	0.01	0.01	0.00

1970	0.29	0.21	0.08	0.03	0.02	0.00

1971	0.25	0.18	0.08	0.04	0.02	0.01

1972	0.55	0.40	0.22	0.08	0.06	0.01

1973	1.68	1.26	0.48	0.18	0.12	0.03

1974	0.29	0.22	0.12	0.05	0.04	0.01

1975	0.07	0.06	0.02	0.01	0.01	0.00

1976	0.19	0.14	0.06	0.02	0.02	0.00

1977	0.07	0.05	0.02	0.01	0.01	0.00

1978	2.70	2.01	0.85	0.31	0.21	0.05

1979	0.08	0.06	0.04	0.03	0.02	0.00

1980	0.44	0.33	0.13	0.05	0.03	0.01

1981	0.19	0.14	0.06	0.02	0.01	0.00

1982	0.80	0.60	0.24	0.10	0.07	0.02

1983	0.05	0.04	0.02	0.01	0.01	0.00

1984	0.77	0.64	0.27	0.11	0.08	0.02

1985	1.26	0.93	0.36	0.14	0.09	0.02

1986	0.09	0.07	0.03	0.01	0.01	0.00

1987	0.01	0.01	0.00	0.00	0.00	0.00

1988	1.69	1.27	0.50	0.20	0.13	0.03

1989	1.67	1.22	0.47	0.17	0.12	0.03

1990	0.60	0.43	0.18	0.07	0.05	0.01

Sorted results

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

0.03	2.70	2.01	0.85	0.31	0.21	0.05

0.06	1.69	1.27	0.50	0.20	0.13	0.03

0.10	1.68	1.26	0.48	0.18	0.12	0.03

0.13	1.67	1.22	0.47	0.17	0.12	0.03

0.16	1.26	0.93	0.41	0.17	0.12	0.03

0.19	0.97	0.70	0.36	0.14	0.09	0.02

0.23	0.91	0.67	0.27	0.11	0.08	0.02

0.26	0.80	0.64	0.26	0.11	0.07	0.02

0.29	0.77	0.60	0.24	0.10	0.07	0.02

0.32	0.67	0.49	0.22	0.08	0.06	0.01

0.35	0.61	0.46	0.21	0.08	0.05	0.01

0.39	0.60	0.43	0.18	0.07	0.05	0.01

0.42	0.55	0.40	0.18	0.07	0.04	0.01

0.45	0.44	0.33	0.13	0.05	0.04	0.01

0.48	0.29	0.22	0.12	0.05	0.03	0.01

0.52	0.29	0.21	0.08	0.04	0.02	0.01

0.55	0.25	0.18	0.08	0.03	0.02	0.00

0.58	0.19	0.14	0.06	0.03	0.02	0.00

0.61	0.19	0.14	0.06	0.02	0.02	0.00

0.65	0.14	0.11	0.04	0.02	0.01	0.00

0.68	0.09	0.07	0.04	0.02	0.01	0.00

0.71	0.08	0.06	0.03	0.01	0.01	0.00

0.74	0.08	0.06	0.03	0.01	0.01	0.00

0.77	0.07	0.06	0.02	0.01	0.01	0.00

0.81	0.07	0.05	0.02	0.01	0.01	0.00

0.84	0.07	0.05	0.02	0.01	0.01	0.00

0.87	0.05	0.04	0.02	0.01	0.01	0.00

0.90	0.03	0.02	0.01	0.01	0.00	0.00

0.94	0.02	0.01	0.00	0.00	0.00	0.00

0.97	0.01	0.01	0.00	0.00	0.00	0.00

0.10	1.67	1.26	0.48	0.18	0.12	0.03

Average of yearly averages:	0.01

Inputs generated by pe4.pl - 8-August-2003

	Data used for this run:

	Output File: NCTobac

	Metfile:	w13722.dvf

PRZM scenario:	NCtobaccoC.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

	31.42

	days

	Halfife

	

	

Anaerobic Aquatic Metabolism	kbacs	0.05	days	Halfife

Aerobic Soil Metabolism	asm	15.71	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	15-4	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	Pond

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

B.3.2 North Carolina Sweet Potato

stored as NCsweet.out

	Chemical: Chloropicrin

	PRZM environment: NCSweetPotatoC.txt,modified Friday, 8 August 2003 at
09:25:48

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

Metfile: w13722.dvf, modified Wedday, 3 July 2002 at 09:05:50

Water segment concentrations (ppb)

	Year	Peak	96 hr	21 Day	60 Day	90 Day	Yearly

1961	1.21	0.96	0.37	0.14	0.09	0.02

1962	0.13	0.10	0.06	0.05	0.03	0.01

1963	0.97	0.73	0.36	0.14	0.10	0.02

1964	0.12	0.09	0.03	0.02	0.02	0.00

1965	0.32	0.23	0.12	0.06	0.05	0.01

1966	0.99	0.76	0.36	0.17	0.12	0.03

1967	0.51	0.36	0.15	0.11	0.09	0.02

1968	0.29	0.21	0.08	0.04	0.03	0.01

1969	0.21	0.16	0.09	0.04	0.04	0.01

1970	0.53	0.37	0.15	0.05	0.05	0.01

1971	0.33	0.26	0.13	0.06	0.05	0.01

1972	0.84	0.61	0.30	0.13	0.10	0.03

1973	1.77	1.34	0.51	0.21	0.15	0.04

1974	0.97	0.71	0.34	0.15	0.10	0.03

1975	0.29	0.23	0.11	0.06	0.05	0.01

1976	0.37	0.31	0.14	0.06	0.04	0.01

1977	0.27	0.20	0.09	0.04	0.03	0.01

1978	3.49	2.60	1.12	0.42	0.28	0.07

1979	0.31	0.23	0.16	0.08	0.05	0.01

1980	0.60	0.48	0.19	0.08	0.06	0.01

1981	0.33	0.25	0.12	0.06	0.04	0.01

1982	0.76	0.57	0.23	0.15	0.10	0.02

1983	0.20	0.15	0.08	0.03	0.02	0.01

1984	0.49	0.38	0.18	0.11	0.08	0.02

1985	1.46	1.08	0.44	0.18	0.14	0.04

1986	0.21	0.16	0.06	0.03	0.02	0.01

1987	0.04	0.03	0.01	0.01	0.00	0.00

1988	0.29	0.22	0.09	0.05	0.04	0.01

1989	1.40	1.08	0.46	0.18	0.12	0.03

1990	1.20	0.89	0.41	0.16	0.11	0.03

Sorted results

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

0.03	3.49	2.60	1.12	0.42	0.28	0.07

0.06	1.77	1.34	0.51	0.21	0.15	0.04

0.10	1.46	1.08	0.46	0.18	0.14	0.04

0.13	1.40	1.08	0.44	0.18	0.12	0.03

0.16	1.21	0.96	0.41	0.17	0.12	0.03

0.19	1.20	0.89	0.37	0.16	0.11	0.03

0.23	0.99	0.76	0.36	0.15	0.10	0.03

0.26	0.97	0.73	0.36	0.15	0.10	0.03

0.29	0.97	0.71	0.34	0.14	0.10	0.02

0.32	0.84	0.61	0.30	0.14	0.10	0.02

0.35	0.76	0.57	0.23	0.13	0.09	0.02

0.39	0.60	0.48	0.19	0.11	0.09	0.02

0.42	0.53	0.38	0.18	0.11	0.08	0.02

0.45	0.51	0.37	0.16	0.08	0.06	0.01

0.48	0.49	0.36	0.15	0.08	0.05	0.01

0.52	0.37	0.31	0.15	0.06	0.05	0.01

0.55	0.33	0.26	0.14	0.06	0.05	0.01

0.58	0.33	0.25	0.13	0.06	0.05	0.01

0.61	0.32	0.23	0.12	0.06	0.05	0.01

0.65	0.31	0.23	0.12	0.06	0.04	0.01

0.68	0.29	0.23	0.11	0.05	0.04	0.01

0.71	0.29	0.22	0.09	0.05	0.04	0.01

0.74	0.29	0.21	0.09	0.05	0.04	0.01

0.77	0.27	0.20	0.09	0.04	0.03	0.01

0.81	0.21	0.16	0.08	0.04	0.03	0.01

0.84	0.21	0.16	0.08	0.04	0.03	0.01

0.87	0.20	0.15	0.06	0.03	0.02	0.01

0.90	0.13	0.10	0.06	0.03	0.02	0.01

0.94	0.12	0.09	0.03	0.02	0.02	0.00

0.97	0.04	0.03	0.01	0.01	0.00	0.00

0.10	1.45	1.08	0.46	0.18	0.14	0.03

Average of yearly averages:	0.02

Inputs generated by pe4.pl - 8-August-2003

	Data used for this run:

	Output File: NCsweet

	Metfile:	w13722.dvf

PRZM scenario:	NCSweetPotatoC.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

	31.42

	days

	Halfife

	

	

Anaerobic Aquatic Metabolism	kbacs	0.05	days	Halfife

Aerobic Soil Metabolism	asm	15.71	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	15-4	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	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 \l2 "Appendix C:  Ecological
Effects Data 

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  TC \l3 "a.  Toxicity to Terrestrial
Animals 

	  i.  Birds, Acute and Subacute  TC \l4 "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  TC \l4 "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)  TC \l4 "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  TC \l3 "b.  Toxicity to
Freshwater Aquatic Animals 	

	i.  Freshwater Fish, Acute  TC \l4 "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.

Rainbow Trout

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

	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  TC \l4 "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  TC \l4 "(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

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  TC \l4 "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  TC \l3 "c.  Toxicity to
Estuarine and Marine Animals 

	i.  Estuarine and Marine Fish, Acute  TC \l3 "	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  TC \l3 "	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  TC \l3 "	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  TC \l3 "	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  TC \l3 "d.  Toxicity to Plants 

	i.  Terrestrial Plants  TC \l4 "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  TC \l4 "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 \l2
"Appendix D.  The  Risk Quotient Method and Levels of Concern 

	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 \l1 "Appendix E.    Data
Requirement Tables 

	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	S

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

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

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

162-3	Anaerobic Aquatic Metabolism	Y	43759301	S

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

p={i-a} OVER {n+1-2a}

p={i} OVER {n+1}

p SUB 1={1} OVER {30+1}=0.03226