Page 2 of 62 

## Problem Formulation for the Environmental Fate, Ecological Risk, Endangered Species, and Drinking Water Exposure Assessments in Supp ort of the Registration Review of Chloropicrin

T ABLE OF 

### C ONTENTS

1. EXECUTIVE SUMMARY

................................ ................................ ......................... 3

2. INTRODUCTION

................................ ................................ ................................ ....... 4

3. USE CHARACTERIZ ATION

................................ ................................ ..................... 5

3.1. Use Sites

................................ ................................ ................................ ............... 5

3.2. Antimicrobial Uses

................................ ................................ ............................... 6

3.3. Typic al Agricultural Methods

................................ ................................ .............. 7

4. CONCLUSIONS FROM PREVIOUS ASSESSMENTS

................................ ............ 8

4.1. Ecological Risk Assessments

................................ ................................ ............... 8

4.2. Drinking Water Exposure Assessments

................................ ............................... 8

4.3. Clean Water Act Programs

................................ ................................ ................... 8

5. ENVIRONMENTAL FATE AND TRANSPORT

................................ ...................... 9

5.1. Fate and Transport in Soil and Water

................................ ................................ . 11

5.2. Movement in Wood

................................ ................................ ............................ 12

5.3. Fate and Transport in Air

................................ ................................ ................... 12

5.4. Transformation Products

................................ ................................ .................... 14

6. RECEPTORS

................................ ................................ ................................ ............. 15

6.1. Effects to Aqua tic Organisms

................................ ................................ ............ 16

6.2. Effects to Terrestrial Organisms

................................ ................................ ........ 17

6.3. Ecological Incidents

................................ ................................ ........................... 19

7. EXPOSURE PATHWAYS OF CONCERN

................................ ............................. 20

7.1. Agricultural Uses

................................ ................................ ................................ 20

7.2. Antimicrobial Uses

................................ ................................ ............................. 21

8. ANALYSIS PLAN

................................ ................................ ................................ .... 21

8.1. Stressors o f Concern

................................ ................................ ........................... 21

8.2. Measures of Exposure

................................ ................................ ........................ 22

8.3. Measures of Effect

................................ ................................ ............................. 25

8.4. Antimicrobial Uses

................................ ................................ ............................. 25

9. Endan gered Species Assessments

................................ ................................ .............. 26

10. Endocrine Disruptor Screening Program

................................ ................................ ... 27

11. PRELIMINARY IDENTIFICATION OF DATA GAPS

................................ .......... 27

11.1. Environmental Fate

................................ ................................ ......................... 27

11.2. Effects

................................ ................................ ................................ ............. 28

12. REFERENCES

................................ ................................ ................................ .......... 34 Appendix A. SIP an d STIR Results

................................ ................................ ................... 40 Appendix B. Field Volatility Study Summaries

................................ ............................... 42Page 3 of 62 1. EXECUTIVE SUMMARY

The Environmental Fate and Effects Division (EFED) and the Antimicrobials Division (AD) ha ve completed the preliminary problem formulation for the ecological risk, environmental fate, endangered species, and drinking water assessments to be conducted as part of the registration review of chloropicrin (PC 081501; CAS Registry Number 76

- 06

- 2)

. The problem formulation describes the methods plan ned for the completion of drinking water and ecological r isk assessments and provide s an ove rview of the environmental fate, ecological effects , and potential risks associated with the use of chloropicrin. The problem formulation also addresses uncertain t ies unique to risk assessment of chloropicrin . This document identifies additional studies that would be beneficial to the conduct of an ecological risk assessment for the conventional uses

. No further assessment is planned for the antimicrobial uses as exposure from these uses is expected to be negligible. Major findings include:

Environmental fate and transport data gaps :

• 835.4300

– Aerobic aquatic metabolism

• 850.6100

– ECM and ILV studies in air and water

Eco toxicology data gaps:

• Aquatic

o 850.45 00

– Aquatic non

- vascular plant studies

• Terrestrial

o 850.4100

– Seedling emergence study

o 850.4150

– Vegetative vigor vapor exposure study with additional species*

o Non

- guidelin e

– Avian acute inhalation study with bobwhite quail *

o Non

- guideline

– Acute h oney bee vapor exposure study *

*A protocol should be submitted to the Agency for approval prior to initiating the study.

Major uncertainties:

The largest uncertainty in quantifying aquatic exposure in this assessment will be the impact of tarps, especially bedde d tarps, on the likelihood of chloropicrin to run off the field and the concentration of chloropicrin in the runoff. Another uncertainty is the impact of rainfall occurring close to the time of application on the runoff and

volatilization rates of chloro picrin in the environment.

For terrestrial exposure, estimated environmental concentrations (EECs) in air will conservatively assume that birds and mammals are not transient and are exposed to emissions of chloropicrin downwind from the treated field. Such an assumption is perhaps more representative for plants since they are not transient. One uncertainty for air EECs is the propensity for large exposures to occur on timescales less than one hour. Such conditions are often associated with temperature inversions when light and var iable wind speeds and highly stagnant air with limited mixing can occur. Therefore, peak airPage 4 of 62 concentrations may be underestimated by modeling . However, it is not expected that these conditions would significantly impact the expected frequency of exposure events since these conditions may only occur within a few hours of some days after fumigant applications.

In addition, current labels contain specific language restricting applications during temperature inversions citing a number of criteria indicatin g the presence or forecasted temperature inversion. Another uncertainty includes the consideration of field size for the quantification of air EECs. Air EECs will be based on emissions occurring from a

maximum field size of 80 acres. Eighty acres is con sidered to be the upper

- bound field size for the maximum area that is typically treated in one day.

2. INTRODUCTION

Chloropicrin is a broad spectrum fumigant used in pre

- plant fumigations and

antimicrobial wood treatments

. 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 ( USEPA, 2007 c ). Chloropicrin is commonly formulated along or with methyl bromide or telone (1,3

- dichloropropene) as an emulsifiable concentrate, soluble concentrate/liquid, ready

- to

- use liquid, or pressurized gas when applied as a pre

- plant soil fumigation (USEPA, 2013)

.

Chloropicrin is volatile and is expected to reside mainly in the gas phase following application. For soil uses, it is expected that post

- application soil sealing methods (e.g., tarps, water, or soil) will be the largest factor determining off

- site mo vement of dissolved chloropicrin vapors via runoff to water bodies or chloropicrin vapors to air. Given its high water solubility, leaching of dissolved chloropicrin vapors to ground water is also possible in well

- draining sandy soils in areas where the w ater table is shallow. Once in water, chloropicrin aquatic exposure will be mediated by volatilization.

EFED and AD evaluated the most recent ecological risk assessments for chloropicrin in association with the most recent toxicity, exposure, and usage i nformation to determine if sufficient data are available and if further updates are needed to support registration

review. Recent ecological risk assessments include a 2009 amended reregistration eligibility decision (RED) assessment (USEPA, 2009 a ) and a 2007 California red legged frog assessment (USEPA, 2007 c ).

In addition, EFED and AD considered the latest Agency science policies and risk assessment methodologies.Page 5 of 62 3. USE CHARACTERIZATION

Chloropicrin is a broad spectrum fumigant with fungicidal, herb icidal, insecticidal, nematicidal, and bacteriocide/bacteriostat properties that is often combined with other fumigants to broaden the pest control spectrum. Chloropicrin was initially registered in

the U.S. in 1975 for use on agricultural crops/soils, gr eenhouse soils, and ornamentals, as wood protection treatments, and for enclosed space fumigation. However, under the Reregistration Eligibility Decision (RED) for chloropicrin issued in 2008 and amended in 2009, structural greenhouse and/or enclosed space fumigation of commodities or other

uses were canceled and additional restrictions were added for the pre

- plant soil uses. At the time of reregistration, the maximum application rate supported for chloropicrin was 350 lbs a.i./A, with 300 lbs a

. i

. /A the maximum for drip irrigation (USEPA, 2008). All chloropicrin labels have been updated to reflect these application limits.

Chloropicrin is commonly formulated alone or with methyl bromide or telone (1,3

- dichloropropene) as an emulsifiable concentrate, soluble concentrate/liquid, liquid ready

to use, or as pressurized gas and applied as a pre

- plant soil fumigation and soil broadcast

treatment. Chloropicrin is applied using tractor

- mounted and other soil fumigation injection equipment, shank s, chisels, plowsoles, drip irrigation, hand operated soil injection equipment, shampoo machines, and encapsulated vials (USEPA, 2013)

.

3.1. Use Sites

Chloropicrin is registered for use as an agricultural pre

- plant soil fumigant for crops including beans, b eets, bell peppers, caneberries, carrots, citrus, cole crops, cucumber, cucurbit vegetables such as melons, deciduous fruit trees, eggplant, field crops such as

co rn , soybeans, and sugar beets, fruits unspecified, ginger, grapes, hops, legume vegetables, l ettuce, mint, onions, orchards, peanuts, pepper, pineapple, potatoes, radish, stone fruit, strawberry, sweet potatoes, tomatoes, tree nuts, yams, and other vegetables.

Other registered non

- food sites include Christmas tree plantations, conifers, forest

nursery plantings (for transplant purposes), forest plantings (reforestation programs), golf course turf, nonagricultural uncultivated areas/soils, nursery stock, ornamental and/or shade trees, ornamental grasses, ornamental herbaceous plants, ornamental l awns and turf, ornamental nonflowering plants, ornamentals unspecified, ornamental woody shrubs and vines, potting soil/top soil, recreation area lawns, preplant soil, tobacco, and wood protection treatment to buildings/products outdoor, forest products (s easoned), and

a quatic structures/items.

The Biological and Economic Analysis Division (BEAD) has generated a chemical profile report for chloropicrin ( USEPA, 2013). The usage is divided into agricultural usage and non

- agricultural/non

- food usage

. Approx imately 10 million pounds of chloropicrin were applied on average annually between 1998 and 2011 to 200,000 acres at an overall average application rate of 50 lbs a

. i

. /acre.Page 6 of 62 For agricultural usage, the top crops in terms of pounds a.i. applied during th e 2007

- 2011 period were strawberries (33%), tobacco (20%), tomatoes (17%)

, peppers (11%) , and others (19%)

. The o ther crops include almonds, apples, beans, cabbage, caneberries, cantaloupes, carrots, cherries, cotton, cucumbers, wine grapes, onions, orang es, peaches, peanuts, plums/prunes, potatoes, pumpkins, squash, sugar beets, sweet corn, walnuts, and

watermelon. The top states in terms of pounds a.i. applied during th e same period were California (33%), Florida (28%), and North Carolina (20%) . O ther states include AL, AR, AK, CO, GA, ID, IN, KY, MI, NE, NM, NY, OR, PA, SC, TN, TX, VA, and WA.

For non

- agricultural/non

- food usage, the use s of chloropicrin in nurseries and in

floriculture are summarized in Table 1 below. The last available year of data (2009)

shows the highest total pound applied, with the lowest average application rate ; this is due to the much larger application area.

Table 1 . Chloropicrin Use in Nursery and Floriculture: Total Applied and Rate per Acre

Year Pounds A.I. Applied Avg A.I. Rate (lb a.i./acre)

2003 255,000 121.6

2006 253,600 122.9

2009 433,500 105.4

Source: USDA N ASS Agricultural Chemical Usage Reports, Nursery & Floriculture, 2003,
2006, and 2009

.

3.2. Antimicrobial Uses

The antimicrobial uses of chloropicrin are restricted to internal treatment of wood to prevent decay. Timberfume II ® (Reg No. 75340

- 1) is registered for use as a pr eservative to prevent internal decay in wooden poles/timbers, in

- place treatment of wood piles, poles, and timbers (using special Osmose® equipment), and for poles, piles, and timbers

in terrestrial sites. The label also allows for the treatment of in

- ser vice wood in aquatic sites. Square

- sawn timbers (e.g. caps, stringers 1 ) require holes of 13/16 th inch diameter at two (2) foot intervals from the bottom surface of timber. Pilings require four holes of

13/16 th inch diameter at 12

- 14 inches of depth. The first hole must be at least two (2) feet above the water line or the high tide mark and succeeding holes are to be 6 inches higher

at 90 o rotation from the next lower holes. A piling with 12 feet above the wat er line should be drilled with eight (8) holes for fumigant treatment. The range of application

rates is 0.44

- 2.2 lbs/piling with all application occurring > 2 feet above the high tide mark. To reduce exposure, the label requires plugging the pre

- drilled holes immediately after application and restricts the use to outdoor structures and beams. The application rate for landscape timbers (3” x 5” x 8’) is 0.31 lb/timber.

Ashta Gold ® (Reg No. 62531

- 2) is registered for use as a preservative to prevent inter nal decay in wooden poles/timbers, pilings, and glue

- laminated beams. The label requires a

minimum of four treatment holes with a diameter of 3⁄4 inch to reach the center of the

1 Stringers are longitudinal support beams and caps are transverse support beams in a pier, http://www.fs.fed.us/t

d/bridges/documents/tbi/wooddef.pdfPage 7 of 62 wood pole. Successive holes are 6

- 12 inches above the previous holes. The rang e of application rates is 0.44

- 2.2 lbs of chloropicrin per pole.

3.3. Typical Agricultural Methods

In general, two most frequent options of chloropicrin application methods include shank injection (soil injection) followed by tarping, or water sealing and drip irrigation (chemigation) under a pre

- tarped soil surface; however

, tarping is not required. 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 applic ation 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. For the production of some crops, the entire field is

treated and referred to as a “flat fume” application or a “ broadcas t application

. ” For the production of other crops, fumigation occurs when planting beds are formed. A bed press forms a raised bed and the fumigant is injected into the bed as it is formed. The entire bed, or only a portion of the bed, is fumigated. This is referred to as a “strip” treatment or a “bedded application

. ” The production of some ornamentals and strawberries use a combination of techniques. First, the entire field is fumigated and tarped. Following fumigation t he tarps are removed, raised beds are formed, and these beds are then tarped without further fumigation

. There are a range of tarps used to reduce emission from the fumigated field ( Table 2 ). Low density polyethylene (LDPE) and high density polyethylene (HDPE) are most commonly used for tarping. Recently, high barrier impermeab le film ( e.g. , virtually impermeable film or VIP) was introduced to reduce emission from the fumigated field.

Table 2

. Summary of Recommended Fumigation Techniques*

Application

Method Application Equipment Soil Incorporation

Method Field

Treatment Application Type Tarping / Sealing Method

Water Seal Tarp

Shallow

shank S pray blade,

shank Roller, rotary harrow, bed

press Entire field, strip (may

be entire bed or only part of the raised bed) Flat fume or

raised bed None, standard,

intermittent Untarped

LDPE

HDPE High barrier

Deep shank Shank Roller, rotary harrow, bed

press Entire field, strip (entire bed) Flat fume or

raised bed N/A Untarped

LDPE

HDPE High barrier

Chemigation Drip line None (drip tape(s) under

tarp ) Entire field, strip (entire bed) Flat fume or raised bed N/A Untarped

LDPE

HDPE High barrier

*Combinations of formulation, application methods and equipment, soil incorporation methods, field treatments, and tarping / sealing methods vary by fumigant, crop, and geographic region. Note that not all potential combinations are used ( e.g. , water seals are not used with tarps).Page 8 of 62 4. CONCLUSIONS FROM PREVIOUS ASSESSMENTS

4.1. Ecological Risk Assessments

The Agency has conducted multiple ecological risk assessments on chlor o picrin that

serve as a basis for this scoping document, including an amended reregistration eligibility decision (RED) assessment in 2009 (USEPA, 2009 a ) and a California red legged frog (CRLF) litigation assessment in 2007 (USEPA, 2007 c )

. The RED identified acute risk concern for all exposed aquatic and terrestrial organisms. It also identified risk via

inhalation to birds and mammals. The CRLF assessment concluded that chloropicrin i s likely to adversely affect the CRLF due to the potential for direct toxicity to aquatic and terrestrial phases of the frog, as well as the potential for indirect effects to food supply,

habitat and designated Critical Habitat. The major ecological risk conclusions from these

assessments are summarized in Table 3

. Maximum EECs in air calculated for these assessments were 0.019 mg/L using the Industrial Source Complex: Short

- Term Model (ISCTS3) with a 24

- hour time

- weighted average and 0.0042 mg/L using the Probabilistic Exposure and Risk model for Fumigants (PERFUM ) with a 4

- hour averaging period. Maximum aquatic EECs calculated using the Pesticide Root Zone Model coupled with the Exposure Analysis Model ing System ( PRZM/EXAMS ) were 7 9 , 19, and 6.8 μg/L for peak, 21

- day average, and 60

- day average, respectively.

Ta ble 3 . Summary of Risk Concerns Identified for Chlor o picrin in Previous Assessments

Birds Mammals Terr.

Plants Terr.

Inverts Fish Bioaccum

ulation Aquatic

Inverts Aquatic

Plants Groundwater

Contamination Persistence Degrad

at es of

Concern

Yes Yes Yes Yes Yes No Yes Yes Yes No None

4.2. Drinking Water Exposure Assessments

Although qualitative drinking water exposure assessments have been done in the past, the Health Effects Division (HED) has not conducted a dietary assessment for chloropicrin and no quantitative drinking water exposure assessments have been completed

. The HED RED assessment acknowledged that chloropicrin is formed during the chlorination process of drinking water and noted that available mo nitoring data indicate that levels of chloropicrin in drinking water from its use as an agricultural fumigant are lower than those detected during the chlorination process (USEPA, 2009 b ).

4.3. Clean Water Act Programs

Chloropicrin is not identified as a cause of impairment for any water bodies listed as impaired under section 303(d) of the Clean Water Act ( http://iaspub.epa.go v/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_grou p_id=885 )

. No Total Maximum Daily Load (TMDL) criteria ( http://iaspub.epa.gov/waters10/attains_nation_cy.control?p_report_type=T#tmdl_by_pol

lutant ) have been developed for chloropicrin.Page 9 of 62 Some aquatic life benchmarks have been published for chloropicrin and are listed in

Table 4 belo w ( http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm )

. These benchmarks have n ot yet been updated to reflect the most recent toxicity data.

Table 4 . OPP Aquatic Life Benchmarks (μg/L freshwater)

Fish Invertebrates Nonvascular Plants Vascular Plants

Acute Chronic Acute Chronic Acute Acute

<8.49

-- <36

-- -- --

The Agency invites submission of water quality data for this pesticide. To the extent possible, data should conform to the quality standards of the OPP Standard Operating Procedure: Inclusion of Impaired Water Body and Other Water Quality Data in OP P’s Registration Review Risk Assessment and Management Process (see: http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1

- sop.pdf ), in order to ensure they can be us ed quantitatively or qualitatively in pesticide risk assessments.

5. ENVIRONMENTAL FATE AND TRANSPORT

Chloropicrin is a clear, colorless, nonflammable oily liquid with a strong, sharp, highly irritating odor and a strong lacrimator. Selected physic o

- chemical and environmental fate properties of chloropicrin are listed in Table 5

. The high vapor pressure (23.8 torr at
25 ○ C), high Henry’s Law Constant (2.05 X 10 - 3 atm m 3 /mole), and low soil adsorption coefficient (K

oc = 36.05 L kg - 1 ) on soil of chloropicrin suggest th at volatilization is the most important environmental route of dissipation

. Direct photolytic degradation (t 1/2 <8 hrs) of chloropicrin is the primary route of dissipation in the atmosphere, which suggest it is not a significant threat to deplete stratosp here 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 adsorpti on to the soil particles

, will depend on chloropicrin emiss ion 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

- li fe rang es less than one day with CO 2 being the terminal breakdown product. Since chloropicrin has low adsorption in soil, it can potentially leach into groundwater and to surface water through runoff under a flooded condition. However, because it degrades quickl y, it is unlikely to persist there when it does reach groundwater. The low octanol/water partition coefficient of chloropicrin also indicates that it is not likely to be bioconcentrated i n tissues of aquatic organisms.

Table 5

. Physical and Chemical Properties of Chloropicrin

Parameter Value Source (MRID)

Chemical Identifiers

Chemical Structure

--

PC Code 081501

-- Cl

Cl Cl

N O 2Page 10 of 62 Parameter Value Source (MRID)

CAS number 76

- 06

- 2

--

Common name Chloropicrin

--

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

--

IUPAC name trichloronitromethane Merck Index

CAS name trichloronitromethane Merck Index

Molecular formula CCl 3 NO 2 43613901

Physical/Chemical Parameters

Molecular weight 164.38 g/mol 43613901

Physical State Near colorless, oily liquid Merck Index

Melting point/range

- 69.2 ○ C Merck Index

Boiling point/range 112 ○ C at 757 torr Merck Index

Density 1.7 g/mL at 25 ○ C Merck Index

Water solubility 1.612 g/L at 25 ○ C 43613901

Vapor pressure 23.8 torr at 25 ○ C Merck Index

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

Octanol/water partition coefficient ( K OW ) 2 40 Kawamoto and Urano, 1989

Persistence

Hydrolysis t 1/2 N o evidence of degra da tion at pH 5, 7, and 9 43022401

Photolysis t 1/2 in water 1.3 days 42900201

Photolysis t 1/2 in air 20 days 05007865

Aerobic Soil m etabolism t 1/2 0.3 days 43613901

Anaerobic a quatic metabolism t 1/2 0.4 days 43759 3 01

Laboratory Volatility Non

- tarped soil maximum volatility 342 μg/cm 2 /hr; Tarped soil maximum volatility 205 μg/cm 2 /hr 43798601

Field Volatility Flux estimated among 16 filed

studies : range from 0.94 to

211 μg/m 2

- s 44149201, 48087401, 47576901,
46420201, 47679301, 48085701, 47456001, 48006001, 47813901, 45112901, 48107601, 47295202, 45112902, 48033801, 47295204

47295203

Mobility

Column Leaching

- Mobility chloropicrin is very mobile in

all four soils tested 44191301

Field Dissipation

Terrestrial Field Dissipation ≤1. 0 day 43085101Page 11 of 62 5.1. F ate and Transport in Soil and W ater

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 volatilized, chloropicrin degrades rapidly into CO 2 and other metabolites in the atmosphere via direct photolysis. The importance of other competing processes such as leaching, biodegr adation, 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 sy stem. The biodegradation half

life of chloropicrin is 0.3 days with carbon dioxide being the terminal breakdown product (MRID 43613901). Also, a cursory review of litera ture data (Wilhelm et al., 1996; Gan et al., 2000) shows that major metabolic pathway s occurs through successive reductive dehalogenation of chloropicrin to nitromethane:

CCl 3 NO 2 

### → HCCl 2 NO 2 

### → H 2 CClNO 2 

### → H 3 CNO 2 

### → CO 2

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.

Chloropicrin is highly soluble in water and weakly retained by soil. The supplemental terrestrial field dissipat ion studies (MRID 43085101) were conducted in California, applying chloropicrin to bare fallow soils at the rates of 665 lbs and 792 lbs a.i/acre through chisel injection followed by tarping with 1 mL polyethylene tarps for 48 hours.

The calculat ed field dissipation half

- life was less than 21.7 hours. Volatilization of chloropicrin from applied fields may have resulted in short half

- lives in the field dissipation study. Concentrations of chloropicrin at the 24

- , 36

- , and 48

- inch depths

increased to a max ima 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 M 3 /mole) and rapid photohydrolysis of chloropicrin suggest t hat 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 hydrolyze in sterile aqueous buffered solution under acidic to alkaline pH (MRID 43022401).Page 12 of 62 Soil adsorption coefficient (K

oc ) of chloropicrin cannot be estimated from the batch equilibrium study. Due to the rapid volatilization of chloropicrin, it is unlikely that an equilibriu m o f chloropicrin in the batch equilibrium will be reached. The K

oc of chloropicrin was estimated using the EPA’s computer model PCKOCWIN v1.66 of

EPISUITE. EPI's K

oc estimations are based on the Sabljic molecular connectivity

method. The estimated K

oc of chloropicrin is 36.05 ml/g. Chloropicrin’s high water solubility (1621 mg/L) and low K

oc 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 grou ndwater 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

tested

.

5.2. Movement in Wo od

Movement of chloropicrin vapor in wood (diffusion rate) depends on wood permeability, moisture content, grain direction, and ambient temperature (MRID 00013189). The longitudinal diffusion rates in Douglas Fir wood were temperature and moisture depend ent and ranged from 1.39

- 1.49 , 1.55

- 2.76, and 4.22

- 5.29 * 10 6 cm 2 sec - 1 at 11, 21, and 32 o C, respectively. The diffusion rate generally increases with increasing temperature and moisture content of wood (MRID 00013189). In creosoted Southern

Pine wood , chloropicrin moved up to 36 inches both upwardly and downwardly. This movement occurred in a few days versus a service life of years, and the study author indicates equal movement in above

- ground railroad ties, caps, and stringers (MRID 00013177).

5.3. Fate and Transport in Air

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). However, a later study using a light source that better

simu lated 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 ch loride, which rapidly photolyze to reactive products NO and Cl• (Carter et al., 1997). Continued oxidation of the chloropicrin photolysis products would eventually produce CO 2 , NO 2 , N 2 O 4 , and Cl 2 (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 m 3 /mol isPage 13 of 62 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 wou ld likely be limited by atmospheric delivery to the soil or water interface, and hence approximate rates estimated for methyl brom ide (Shorter et al

., 1995; Yvon and Butler

, 1996).

An overall atmospheric lifetime for chloropicrin can be computed using the procedure followed by USEPA 2005 b , in which an overall ‛total lifetime’ is computed from estimates of lifetimes computed from photodegradation, oceanic uptake and terrestrial uptake:

1/τ total = 1/τ p + 1/τ

o + 1/τ

s

where τ p , is the atmospheric lifetime as sociated with processes of direct and indirect photo and chemical degradation and precipitation scavenging; and τ

o ,and τ

s 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 u ptake 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 10 6 metric tons pro duced 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 s to be a minor source o f atmospheric phosgene relative to other sources. Additionally, phosgene is expected to quickly degrade, hydrolyzing to CO 2 , HCl, and NOCl, producing NO, N 2 O 4 , and Cl 2 (MRID 05007865)

.Page 14 of 62 The reactive byproducts of chloropicrin photolysis, in particular chl orine free radicals and

NO

x , 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 pollutant s contributing to the problem (Carter et
al. , 1997). Therefore, the stratospheric ozone depletion will not be a concern with the use of chloropicrin as a fumigant based on its ozone depletion potential of 5.6*10 - 5

.

5.4. Transformation Products

The major degradates of chloropicrin in submitted environmental fate studies were chloronitromethane, nitromethane (in a na erobic aquatic )

, carbon dioxide (in aerobic soil)

, phosgene and nitrosyl chloride (in air photolysis) . A variety of minor degradates were observed in the some studies

. Table 6 summarizes the transformation products of chloropicrin and their maximum amounts formed.

Table 6

. Chloropicrin and Its Major Environmental Degradates

Code Name/

Synonym Chemical

Name Chemical

Structure Study
Type Ref erence (MRID) Maximum

%AR
(day) Final

%AR (study length)

PARENT

Chloropicrin Trichloromethane

Formula:

CCl 3 NO 2

MAJOR /MINOR TRANSFORMATION PRODUCTS

Nitromethane Formula: CH 3 NO 2 Aerobic

soil 43613901 2% ( 24 d) 2% ( 24 d)

Anaerobic

aquatic 43 759301 5 7. 3 % (1 d) (53.4%

water, 3.3% soil) n.d. ( 54 d)

Column Leaching 44191301 3.7%

Chloronitromethane Formula:

CH 2 Cl NO 2 Anaerobic aquatic 43 759301 53.1% (4 hrs) (51.5%

water, 1.6% soil) 0.1%

. ( 54 d)

Aerobic

Soil 43613901 3.8% (14 d) 1.6% (24 d)

Column Leaching 44191301 12% Cl

Cl Cl

N O 2

H

H H

N O 2

Cl

H H

N O 2Page 15 of 62 Code Name/

Synonym Chemical

Name Chemical

Structure Study
Type Ref erence (MRID) Maximum

%AR
(day) Final

%AR (study length)

D ichloromethyl

hydroxylamine Formula:

CH 3 Cl 2 NO Column Leaching 44191301 16.4%

Carbon dioxide Formula: C O 2 Aerobic

Soil 43613901 69% (24 d) 69% (24 d)

Anaerobic

aquatic 43 759301 4.1% (24 d) 4.1% (24 d)

Aquatic Photolysis 4290020 1 1.43e

- 4 (Mol/L) (108 hr) 1.43e

- 4 (Mol/L) (108 hr)

Phosgene Formula: CO Cl 2 Air Photolysis 05007865 71.7% (70 d) 71.7% (70 d)

Nitrosyl Chloride Formula: NO Cl Air Photolysis 05007865 41.7% (38 d) 32% (70 d)

Carbonate Formula: C O 3 - 2 Aerobic

Soil 43613901 2% (21 d) 1.5% (24 d)

Bicarbonate Formula: H C O 3 - Aquatic Photolysis 4290020 1 5.73e

- 4 (Mol/L) (108 hr) 5.73e

- 4 (Mol/L) (108 hr)

Nitrate Formula: N O 3 - Aquatic Photolysis 42900201 9.99e

- 5 (Mol/L) (84 hr) 9.23e

- 5 (Mol/L) (108 hr)

Nitrite Formula: N O 2 - Aquatic Photolysis 42900201 1.06e

- 4 (Mol/L) (108 hr) 1.06e

- 4 (Mol/L) (108 hr)

Chloride Formula: Cl Aquatic Photolysis 42900201 2.05e

- 3 (Mol/L) (108 hr) 2.05e

- 3 (Mol/L) (108 hr)

Notes: A n .d. means “not detected”

6. RECEPTORS

Acute (short

- term) and chronic (long

- term) toxicity information is characterized based on registrant

- submitted studies. Many of these studies were submitted and reviewed subsequent to the last assessment. A review of the open literature on chloropicrin will O H

Cl Cl

N H 2

C O O

O O

O

O H O

O

N
O O O

N O

O

ClPage 16 of 62 also be conducted at the time of the risk assessment

. Reported ecological incidents associated with chloropicrin are summarized below in Section 6.3

.

Table 7 and Table 8 provide summaries of the aqua tic and terrestrial taxonomic groups, respectively, and surrogate species tested to characterize the potential acute and chronic ecological effects of chloropicrin

. Based on the available ecotoxicity information, chloropicrin is highly to very highly toxi c to aquatic species on an acute exposure basis. Chronic aquatic toxicity has not bee n tested. Chloropicrin is toxic to mammals and birds

via inhalation . A cute toxic ity to mammals is also evident via oral exposure

. Chloropicrin is practically nontoxic to honey bees via acute contact exposure; other routes of exposure have not been tested. Toxicity of chloropicrin to terrestrial plants was tested via vapor exposure and toxicity was observed in a vegetative vigor study but not in a seedling emergence stu dy. Toxicity to terrestrial species has primarily been tested via inhalation or vapor exposure , the main exposure route of concern due to the high volatility of chloropicrin. Additionally, application of chloropicrin is pre

- plant via soil injection or dr ip irrigation rather than spray application so exposure to terrestrial animals via diet is unlikely.

Beneficial soil organisms exposed within the treated area are not considered in this assessment as chloropicrin is intended to be a soil sterilant. However it is expected that burrowing animals or beneficial soil invertebrates near treated areas may be af fected if there is lateral transport through soils.

Toxicity data with co

- formulated products conducted with laboratory mammals and open

literature data with non

- mammalian species will be examined during the registration review process to determine any additive or synergistic toxicity which may be accounted for in the ecological assessment.

6.1. Effects to Aquatic Organisms

Table 7 . Summary of Aquatic Toxicity Studies for Chloropicrin 1

Taxonomic

Group Study Type Surrogate Species Toxicity Value (all units in terms

of mg/L measured active ingredient) Acute Toxicity

Classification Source (MRID)

Freshwater

fish 2 Acute Rainbow t rout ( Oncorhynchus mykiss ) LC 50 = 0.011 Very highly

toxic 48442405

Bluegill s unfish ( Lepomis

macrochirus ) LC 50 = 0.050 Very highly

toxic 4844240 6

Chronic

-- No data

-- --

Freshwater

invertebrates Acute Daphnia magna EC 50 = 0.12 Highly toxic 48442401

Chronic

-- No data

-- --Page 17 of 62 Taxonomic

Group Study Type Surrogate Species Toxicity Value (all units in terms

of mg/L measured active ingredient) Acute Toxicity

Classification Source (MRID)

Estuarine/

marine fish Acute Sheepshead minnow ( Cyprinodon variegatus ) LC 50 = 0.10 Highly toxic 4844240 2

Chronic

-- No data

-- --

Estuarine/

marine

invertebrates Acute Eastern oyster ( Crassostrea virginica ) EC 50 = 0.010 Very highly

toxic 48442404

Acute Mysid s hrimp ( Mysidopsis bahia ) LC 50 = 0.027 Very highly

toxic 4844240 3

Aquatic plants and algae Vascular Duckweed ( Lemna gibba ) NOAEC = 0.00031

EC 50 = 0.0065 Very highly

toxic 48442801

Non

vascular -- No data

-- --

1 Note: all aquatic toxicity data reported here was submitted and reviewed subsequent to the most recent update of the OPP aquatic life benchmarks.

2 Freshwater fish may be surrogates for aquatic

- phase amphibians.

6.2. Effects to Terrestrial Organisms

Table 8 . Summary of Terrestrial Toxicity Stu dies for Chloropicrin

Taxonomic

Group Study Type Surrogate Species Toxicity Value (all units in terms of

measured active ingredient) Acute Toxicity

Classification Source (MRID)

Birds 1 Acute oral

-- No data

-- --

Sub

- acute dietary -- No data

-- --

Chronic

-- No data

-- --

Acute

inhalation -- No data

-- --

Sub

chronic

inhalation Bobwhite quail ( Colinus virginianus ) NOAEC = 0.00065 mg/L LOAEC = 0.0020 mg/L Endpoint: microscopic changes in respiratory tract NA 48442803

Mammals Acute o ral Laboratory rat ( Rattus norvegicus ) LD 50 = 37.5 mg/kg

- bw Highly toxic 05014376

Acute

i nhalation Laboratory rat LC 50 = 0.114 mg/L

-- 45117902Page 18 of 62 Taxonomic

Group Study Type Surrogate Species Toxicity Value (all units in terms of

measured active ingredient) Acute Toxicity

Classification Source (MRID)

Chronic

i nhalation Rabbit NOAEC = 0.003 mg/L LOAEC = 0.008 mg/L Maternal endpoints: mortality, decreased bw,

decreased food consumption Developmental endpoints: abortions, decreased fetal weight NA 42740601

Insects Acute

contact Honey bee ( Apis mellifera

L. ) LD 50 = >10 0 μg/bee Practically

nontoxic 48442407

Terrestrial plants Seedling Emergence (vapor exposure) Monocot

– corn &

ryegrass NOAEC = 0.068 mg/L

EC 25 = >0.068 mg/L Endpoint: None -- 48442802

Dicot

– cucumber, oilseed rape, soybean, &

sunflower NOAEC = 0.068 mg/L

EC 25 = >0.068 mg/L Endpoint: None -- 48442802

Vegetative Vigor (vapor exposure) Monocot

- ryegrass NOAEC = 0.0070 mg/L

EC 25 = 0.061 mg/L Endpoint: plan t dry weight -- 48442802

Dicot

– oilseed

rape EC 05 = 0.00040 mg/L

EC 25 = 0.0021 mg/L Endpoint: plan t dry weight -- 48442802

1 Birds represent surrogates for terrestrial

- phase amphibians and reptiles.

The submitted avian inhalation study (MRID 48442803) was conducted using 4

- hour exposures for five consecutive days with a subsequent 14

- day observation period. The concentrations tested were sublethal and the most sensitive toxicity endpoint observed was microscopic changes in the respiratory tract. A de crease in body weight was observed at the highest test concentration (0.0044 mg/L) during the exposure period only. An acute avian inhalation study is needed to establish an LC 50 to be used in the risk assessment to calculate risk quotients.

There are no data on chronic toxicity to avian species. This data would be useful to assess risk of growth and reproductive toxicity to birds resulting from chloropicrin vapor inhalation. However, EFED is not requesting chronic avian inhalation toxicity data at

this time due to feasibility considerations. Instead, a weight of evidence approach will be used to characterize potential chronic risk to birds. Chronic mammalian data will be used in this approach where appropriate. Sub

- lethal effects from acute exposure studies will

also be considered.

In the vegetative vigor study (MRID 48442802) , the most sensitive endpoint was dry weight for oilseed rape. However, the study author discounted this endpoint due toPage 19 of 62 “mechanical damage” to the plants incurred during handl ing. Insufficient information was provided to determine the impact of the mechanical damage, and whether growth

inhibition was also a factor. The data followed a clear dose

- response pattern. Therefore, the oilseed rape data will be considered suitable f or quantitative use in risk assessment in the absence of additional information demonstrating why it should not be used . If additional data submitted show greater sensitivity on another species, then that data will be used in place of the oilseed rape dat a

. The study used 6

- hour exposure periods on two consecutive days.

6.3. Ecological Incidents

Three databases were searched for ecological incidents possibly associated with chloropicrin : the Ecological Incident Information System ( EIIS )

, aggregate incident

reports, and Avian Incident Monitoring System ( AIMS )

. The EIIS is an OPP database that houses ecological incidents that have been reported to the Agency. When available, EIIS includes date and location of an incident, type and magnitude of effects obser ved in various species, use(s) of pesticides known or suspected of contributing to the incident, and results of any chemical residue analysis or other analyses conducted during incident investigation. EIIS incidents are categorized according to the certai nty that the incident resulted from pesticide exposure. The Avian Monitoring System (AIMS) is a database administered by the American Bird Conservancy that contains publicly available data on reported avian incidents involving pesticides. Many of the inc idents listed in this

database are also in the EIIS. The aggregate incident reports provide counts of ecological incidents considered “minor.” These are reported to the Agency quarterly by registrants.

EIIS returned four incidents attributed to chloropi crin use
, including one aquatic incident and three terrestrial plant incidents (USEPA, 2007 a ). The aquatic incident involved an

accidental misuse in which chloropicrin was spilled into a waterway from an irrigation

system and 1,000 fish were killed. It w as considered highly probable that this incident was attributable to the spill. Two of the terrestrial plant incidents involved damage to apple and watermelon crops planted in fields treated previously with chloropicrin formulations registered for those uses. The damage was attributed to chloropicrin with probable and possible certainty, respectively. The third terrestrial plant incident involved damage to conifer s eedlings at a nursery attributed with possible certainty to vapor drift following a fumigation with chloropicrin. See Table 9 for a list of the incid ents reported

in EIIS. As of April 11, 2013 , AIMS identified no ecological incidents involving chloropicrin

.

Table 9

. Incidents Reported in EIIS for Chloropicrin

Incident # Date County

, State Certainty

Code 1 Legality

Code 2 Formul

. 3 Appl.

Method Total Magnitude

Terrestrial Plants

I020627

- 022 9/26 /2001 Thurston

, WA 2 UN N/R Fumigation Damage to conifer

s eedlings from vapor

drift

I007358

- 001 1/1 / 1998 WA 3 R U N/R N/R Damage to apple trees planted in a recently

treated fieldPage 20 of 62 Incident # Date County

, State Certainty

Code 1 Legality

Code 2 Formul

. 3 Appl.

Method Total Magnitude

I014702

- 076 9/1 /200 3 San Joaquin

, CA 2 R U RTU Broadcast Mortality of 91 acres of

watermelon seedlings planted in a recently

treated field

Aquatic

I016738

- 016 9/1/2005 Santa Cruz

, CA 4 MA EC Drip 1000 fish deaths

1 Certainty Code: 0=Unrelated, 1=Unlikely, 2=Possible, 3=Probable, 4=Highly Probable. N/R=Not Reported

2 Legality Code: RU=Registered Use, M=Misuse, MA=Misuse (Accidental), MI=Misuse (Intentional), U N =Unknown

3 RTU = Ready To Use

, EC=Emulsifiable Concentrate

The number of documented incidents in EIIS is believed to be a very small fraction of

total morbidity and mortality caused by pesticides for a variety of reasons. Incident reports for non

- target organisms typically provide information only on mortality events and plant damage. Sub

- lethal effects in organisms such as abnormal behavior, reduced growth and/or impaired reproduction are rarely reported, except for phyto toxic effects in terrestrial plants. An absence of reports does not necessarily equate to an absence of incidents given the nature of the incident reporting.

In addition to the incidents recorded in EIIS , registrants have reported minor chloropicrin

inci dents to the Agency in aggregate reports. Registrants reported three minor plant

incidents and one minor wildlife incident between 2005 and 2012 . Unless additional information on these aggregated incidents becomes available, they will be assumed to be

re presentative of registered uses of chloropicrin in the risk assessment.

7. EXPOSURE PATHWAYS OF CONCERN

7.1. Agricultural Uses

The environmental fate properties of chloropicrin indicate that v o latilization , runoff, and leaching represent potential transport mechanisms to aquatic and terrestrial organisms. Due to the application methods of soil injection and drip irrigation, dietary exposure to terrestrial animals is not expected. Drinking water and inhalat ion exposure pathways were screened using the SIP (Screening Imbibition Program) and STIR (Screening Tool for Inhalation Risk) screening methods (see Appendix A. SIP and STIR Results for details). SIP and STIR are described in detail at: http://www.epa.gov/oppefed1/models/terrestrial/index.htm

.

Although exposure via contaminated drinking water is possible for terrestrial animals, the main route of exposure of terrestrial animals to chloropicrin is expected to be through inhalation. For birds, based on chloropicrin’s vapor pressure and calculations using STIR, the maximum 1

- hour v apor inhalation dose for birds is 26,500 mg/kg

- bw. By contrast, based on chloropicrin’s solubility limit and calculations using SIP, the upper bound daily drinking water intake dose for a bird is 1,306 mg/kg

- bw. Multiplying the

STIR estimate of one hour by 12 (to match the daily exposure duration of the SIP estimate) yields 318,000 mg/kg

- bw, which is two orders of magnitude more than the potential drinking water dose. While these estimates are highly conservative as they doPage 21 of 62 not account for dissipation or degradation over the exposure period and they assume that the entire dose is retained in the exposed animals , the relative magnitudes of exposure via the two routes provide useful information. For chloropicrin, this suggests that the potential daily inha lation exposure of a bird is substantially greater than the potential daily drinking water exposure for a bird indicating that inhalation exposure may be of greater concern. The same pattern is seen the model estimates for mammals. Additionally, acute or al and acute inhalation toxicity data are available for the laboratory rat (MRIDs 05014376 and 45117902, respectively). The data indicate that for mammals, chloropicrin is more toxic via inhalation exposure than via oral exposure (oral LD 50 = 37.5 mg/kg

- b w, acute inhalation L D 50 3.1 mg/kg

- bw [converted in STIR from LC 50 0.114 mg/L ] ). Therefore, any risks (and mitigation measures implemented to reduce risks) associated with terrestrial animal exposure to chloropicrin via inhalation are expected to be protective of other potential routes of exposure (including via drinking water)

, and the risk assessment for terrestrial animals and chloropicrin will focus on risks

associated with inhalation.

Exposure in aquatic environments may occur as a result of ru noff and leaching. While chloropicrin is highly volatile, it is also highly solubl e. Therefore, it is expected to reach surface water and has the potential to impact aquatic species. Maximum aquatic EECs calculated using PRZM/EXAMS in previous assessmen ts (USEPA 2007 c and 2009 a ) were 79, 19, and 6.8 μg/L for peak, 21

- day average, and 60

- day average, respectively.

7.2. Antimicrobial Uses

For antimicrobial use as a wood treatment, no environmental exposure is expected and

therefore de minimis risk is anticipa ted. The volume of exposure from treated utility poles, pilings, and landscape timbers is negligible and the Antimicrobial Division is not conducting any further assessment of risk

.

8. ANALYSIS PLAN

8.1. Soil Fumigation: Stressors of Concern

Ecological Risk Assessment

The primary stressor of ecological concern for terrestrial organisms is chloropicrin

. Additionally, chloropicrin’s photodegradation products phosgene (carbonyl chloride) and nitrosyl chloride are recognized to be highly toxic gases

. Both of t hese degradates are expected to quickly degrade, hydrolyzing to CO 2 , HCl, and NOCl, producing NO, N 2 O 4 , and Cl 2 (MRID 05007865). Therefore, these degradates are expected to be short

- lived. For this reason, only chloropicrin will be considered as a stress or of concern in the assessment of risk via inhalation to terrestrial organisms.

Similarly, t he stressor of concern for aqu atic organism s is chloropicrin only.Page 22 of 62 Drinking Water Assessment

Only qualitative drinking water exposure assessment s have been completed for chloropicrin to date. I f a dietary assessment is needed in the future , EFED will provide the drinking water exposure assessment and determine the stressors of concern in conjunction with HED

.

8.2. Soil Fumigation: Measures of Exposure

EFED will use standard available models to evaluate potential exposures to aquatic and terrestrial organisms as described at http://www.epa.gov/pesticides/science/m odels_db.htm

.

The Agency is aware of monitoring conducted by federal and state agencies and this

information will be considered in the assessment to the extent that data on chloropicrin

are available. In monitoring conducted in urban and rural commu nities 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/m 3 ) to 14000 ng/m 3 , with a range of 8

- week average concentrations of 406 to 2270 ng/m 3 . Chloropicrin was undetected in only 7 of 192 samples (CARB 2004). Similar monitoring in Kern County found much lower levels of chloropicrin

.

Aquatic Exposure Modeling

The models used to predict aquatic estimated environmental concentrations ( EECs ) are the Pesticide Root Zone Model coupled with the Exposure Analysis Model ing System (PRZM/EXAMS) publically available at: http://www.epa.gov/oppefed1/models/water/pe5_user_manual.htm

. The PRZM/EXAMS

Standard Pond scenario will be used to estimate the aquatic EECs in surface water. Since both surface chemigation and incorporated chemigation and injection application methods for chloropicrin application exist, two separate runs will be conducted for each crop scenario addressing the surface and incorporated applications. The PRZM volatilization algorithm will be used to address both chloropicrin’s upward movement in soil to the runoff extraction zone and escape to the atmosphere.

Terrestrial Exposure Modeling

Screening level calculations have suggested that the inhalation exposure pathway may be significant for terrestrial wildlife . This exposure pathway is far m ore significant than potential exposure via drinking water and will be further considered at the time of the risk

assessment. Dietary exposure to terrestrial wildlife is not anticipated to result in LOC

exceedances

.

Chloropicrin acute e xposures of the birds, mammals, terrestrial invertebrates, and plants through inhalation and vapor exposure are determined using the EECs from atmospheric dispersion models relying on the input of chloropicrin atmospheric flux measurementsPage 23 of 62 from the collection of field vol atility (flux) studies. For detailed descriptions of the field volatility studies reviewed for chloropicrin, see Appendix B

. Field Volatility Study

Summaries

. Consi stent with the aquatic exposure assessment, the terrestrial ecological risk assessment will assess two separate scenarios addressing surface and incorporated application of chloropicrin. The Agency’s recommended screening dispersion model for

the near fie ld, the American Meteorological Society/EPA Regulatory Screening Model (AERSCREEN), will be used to generate Tier I EECs. The Tier I analysis will consider the maximum flux rate for each application method from the collection of chloropicrin

flux studies and worst

- case meteorological conditions (light winds and stagnant conditions) to calculate peak air EECs, representing one

- hour average concentrations.

Documentation on the AERSCREEN model is available at http://www.epa.gov/scram001/dispersion_screening.htm . The exposure scenario evaluated in the Tier 1 analysis will assume that the terrestrial receptors are directly

downwind from the emissions source. This is illustrated in Figure 1 below

.

Figure 1 . Schematic showing soil fumigant air exposure scenario due to volatilization and subsequent release from soil evaluated in Tier 1 analysis.

If the Tier 1 EECs for either surface or incorporated applications result in an exceedance

of the LOC, EECs will be further examined using the Tier 2 model, the Probablistic Exposure and Risk Model for Fumigants (PERFUM). PERFUM is parameterized by a time series of flux data obtained from field volatility studies. PERFUM considers these flux values with a robust statistical sampling of meteorological data from points within rings surrounding a treated field (usually 5 years of hourly meteorological data). The current version of PERFUM processes estimated air concentrations from EPA’s previously recommended atmospheric dispersion model in the near field, the Industrial

Sourc e Complex Short

- Range Model, Version 3 (ISCST3). ISCST3 has since been replaced by the refined mode of AERSCREEN, the AERMOD model, as the recommended refined dispersion model in the near field. However, both ISCST3 and AERMOD are similar by that they bo th use Gaussian plume dispersion principles. The

framework for PERFUM is illustrated in Figure 2 below. Estimated air concentrations

are calculated a nd binned by percentile distributions within each ring and averaging time period. First, a peak one

- hour averaging period will be used to calculate air EECs. If Wind, Dispersion,

and

Accumulation

of Vapors or Gas

Volatilization of

residues in soil Soil incorporated and chemigation fumigant applicationPage 24 of 62 necessary, a higher averaging period equivalent to the exposure duration in toxicity

studies will be used to characterize the RQs resulting from utilizing the one

- hour peak EECs. The highest 90 th percentile estimated air concentration from all averaging periods from the receptor ring closest to the edge of the field will be considered as the uppe r

bound EEC to determine the RQ. The PERFUM model is publically available on the web

from the follow link: http://www.exponent.com/projectdetail.aspx?project=450 . For this soil fumigant assessment, maximum air exposure will occur at the edge of the field corresponding to

the where chloropicrin mass emissions from the treated field will accumulate to maximum levels along the fetch of wind blowing over the treated field.

Figure 2 . Illustration of the spatial and temporal aspects of the source to receptor configuration in PERFUM. The wind rose (left) illustrates the frequency distribution of variations in wind speed and wind direction that PERFUM accounts for in the transport of the vapor plume from the treated source to receptors (right).

All modeling scenarios will be paramete rized based on field volatility flux data

normalized to an 80 acre field.

For exposure to plant seedlings, TerrPlant will be used unless other approved terrestrial plant exposure models are available . Although TerrPlant EECs are based on runoff, the

co nservative values calculated by TerrPlant will capture the overall exposure of plant seedlings in the soil, whether it occurs from diffusion in the gas phase or runoff of chloropicrin

. The Agency is currently developing a replacement model for TerrPlant. If the replacement has been approved prior to the initiation of the risk assess m ent, this new

model will be used instead.

In addition, chloropicrin dermal and inhalation exposure to organisms residing in soil may occur underneath and nearby fields treated with chloropicrin . An upper

- bound exposure scenario can be extrapolated from the PRZM crop scenarios discussed above

. Treated

Field Receptor RingsPage 25 of 62 8.3. Measures of Effect

Toxi city data presented in Section 6 of this problem formulation will be used to calculate risk quotients. Any additional information submitted by the registrant or found in the open literature prior to conduct of the risk asse ssment will also be considered. The open literature studies are identified using EPA’s ECOTOXicology database ( ECOTOX) (USEPA, 2007 b ), which employs a literature search engine for locating chemical toxicity data for aquatic life, terrestrial plants, and w ildlife. The evaluation of both sources of data can also provide insight into the direct and indirect effects of pesticides on biotic communities from loss of species that are sensitive to the chemicals and from changes in

structure and functional charact eristics of the affected communities.

8.4. Antimicrobial Uses

Treated utility poles 2 , pilings 3 , and landscape timbers 4 represent a de minimis amount of environmental exposure because of the low application rate of chlor o picrin, the low areal density, the slow off

- gassing that occurs over the long useful life of the pole, and the wind that disperses the off

- gassed fumigant. Utility poles are treated at up to 2.2 lbs

a

. i

. /pole 5 and are generally spaced 100

- 150 feet apart 6 . As a result, the only

environmental e xposure is release into air that occurs over time, and the service life of a utility pole is approximately 30

- 40 years. 7 Assuming an application rate of 2.2 lbs/pole,

a minimum 30

- year lifespan, 100 % release from pilings into air, and uniform off

- gassing, the chloropicrin release into the atmosphere is 0.073 lb/year, or 0.0002 lb/day 8 . Like any compound that is released into the air, the presence of wind will di lute the aerial

concentrations. Some wildlife species such as Pileated Woodpeckers 9 ( Dryocopus pileatus) 10 will peck the wood and Edgewater Parrots 11 ( Myiopsitta monachus ) 12 will nest on poles, but the chloropicrin off

- gassing is not expected to cause risk because of the low application rate, slow off

- gassing, and wind.

2 A round timber of any size or length, usually used with the large end in the ground., http://www.fs.fed.us/t

- d/bridges/documents/tbi/wooddef.pdf

3 A long, heavy timber, round or square, that is driven deep into the ground to provide a secure foundatio n for structures built on soft, wet, or submerged sites., http://www.fs.fed.us/t

d/bridges/documents/tbi/wooddef.pdf

4 Long pieces of square or rounded lumber, http://homeguides.sfgate.com/border

- driveway

- landscape

timbers

- 39043.html

5 Amended RED, May 2009, EPA

- HQ

- OPP

- 2007

- 0350

- 0396[1].pdf

6 http://www.sizes.com/materls/utilitypole.htm

7 MRID 00013177, http://products.construction.com/swts_content_files/14 75/593095.pdf

8 2.2 lbs/pole / 30 years /365 days/year

9 S.K. Tupper, W.F. Andelt, J.L. Cummings, C. Weisner, and R.E. Harness. April 2010. Polyurea Elastomer Protects Utility Pole Crossarms From Damage by Pileated Woodpeckers. The Journal of

Wildlife Management 74(3): 605

- 608

10 http://en.wikipedia.org/wiki/Pileated_Woodpecker

11 http://www.nj.com/bergen/index.ssf/2013/03/photos_edgewater_parrot_nests_removed_from_utility_pole s_along_the_palisades .html

12 http://en.wikipedia.org/wiki/Monk_ParakeetPage 26 of 62 In addition, pilings for aquatic use can be treated at 0.44

- 2.2 lbs a

. i

. /piling and the minimum treatment distance above the high tide mark is 2 feet. Treated caps and stringers 13 (horizontal decking and support boards) in a pier are well above the water l ine and also would not create direct aquatic exposure unless rainfall leaches some chloropicrin which falls into a water body. However, the high Henry’s Law constant of

2.1 x 10 - 3 atm m 3 mol - 1 (Kawamoto and Urano, 1989) indicates that any chloropicrin in water is likely to volatilize and not be retained in water. Like treated utility poles, the service life of treated wood used in piers is >25 years 14 and any chloropicrin that dissipates from wood occurs over time into the air (MRID 00013177) . Assuming an application rate of 2.2 lbs/piling, a minimum 25

- year lifespan, uniform off

- gassing, and 100 % release from pilings into air, the chloropicrin release into the atmosphere is 0.088 lb/year, or 0.00024 lb/day 15 . Like any compound that is released into the a ir, the presence of wind will dilute the aerial concentrations of chloropicrin. The effect of wind will be higher in coastal areas with minimal or no cover, while wind is likely to have a lesser effect in areas that are contained. As a result, aquatic ex posure is expected to be minimal because of the low application rate, slow off

- gassing, and wind.

Landscape timbers represent a de minimis amount of environmental exposure of chloropicrin because of the low a pplication rate of chloropicrin, the low area l density,

and the slow off

- gassing that occurs over the long useful life of the timber. They are also expected to last 15

- 20 years in use 16 . Landscape timbers are treated at up to 0.31 lb

a

. i

. /timber 17 and tend to be present in small quantities in indivi dual properties. Thus, they are areally dispersed. As a result, the only environmental exposure is release into air that occurs over time. Assuming an application rate of 0.31 lbs/pole, a minimum 15

- year lifespan, 100 % release from pilings into air, and uniform off

- gassing, the chloropicrin release into the atmosphere is 0.021 lb/year, or 0.000057 lb/day 18

.

Due to the use of chloropicrin as a treatment for utility poles, pilings and landscape timbers, little, if any exposure ( de minimis ) to non

- target organisms would occur. Therefore, no risk to non

- target organisms would occur from the antimicrobial uses of chloropicrin.

9. Endangered Species Assessments

Consistent with the Agency’s responsibility under the Endangered Species Act (ESA), the Agency will evaluate risks to federally listed threatened and/or endangered (listed) species from registered uses of pesticides in registration review

. The process for evaluating potential risks to listed species is further described at http://www.epa.gov/oppfead1/endanger/litstatus/riskasses.htm

.

13 Stringers are longitudinal support beams and caps are transverse support beams in a pier, http://www.fs.fed.us/t

- d/bridges/documents/tbi/wooddef.pdf

14 Koppers Timber Piling Life Expectancy Guide, www.koppers.com.au

15 2.2 lbs/piling / 25 years / 365 days/year

16 http://www.brightonservices.com/retainingwalls.html

17 2.2 lbs chloropicrin/piling * 0.8 ft3/landscape timber / 5.9 ft3/ piling

18 0.31 lbs/pole / 15 years /365 days/yearPage 27 of 62 10. Endocrine Disruptor Screening Program

Chloropicrin was not included in the first group of 67 chemicals issued an order to conduct Tier 1 EDSP testing nor in the second group of 109 chemicals

. For additional information the EDSP program, visit http://www.e pa.gov/endo/

.

11. PRELIMINARY IDENTIFICATION OF DATA GAPS

11.1. Environmental Fate

Table 10 identifies environmental fate studies by MRID that offer data for each guideline requirement, study classifications and if additional data are warranted to support a risk

assessment. EFED re commends requesting the following studies to assess the

environmental risks associated with the use of chloropicrin for soil fumigation :

• 835.4300

– Aerobic aquatic metabolism

• 850.6100

– ECM and ILV studies in air and water

No additional environmental fate data is needed to further assess the antimicrobial uses of chloropicrin.

Table 10 . Submitted Environmental Fate Data f or Chloropicrin

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

835.2120 Hydrolysis 43022401 Acceptable No

--
835.2240 Aqueous photolysis 42900201 Supplemental No

--

835.2410 Soil Photolysis 05007865 Acceptable No S tudy waived . B ecause chloropicrin is used by soil injections, no substantial soil photolysis is expected

. 835.2 370 Air photolysis 05007865 Acceptable No

--

835.4100 Aerobic soil

metabolism 43613901 Acceptable No

835.4200 Anaerobic soil

metabolism 4147860 1 Unacceptable No Use anaerobic aquatic metabolism study results

835.4300 Aerobic aquatic

metabolism (None) (N/A) Yes A laboratory aquatic study is

needed to determine chloropicrin’s residence time in

water. See additional details

below.

835.4400 Anaerobic aquatic

metabolism 43759301 Acceptable No

--Page 28 of 62 OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

835.1230

835.1240 Adsorption/ desorption and leaching 44191301 Supplemental No

--

835.1410 Volatility

– laboratory 43798601 Acceptable No

--

835.6100 Terrestrial field dissipation 43085101 Supplemental No

850.1730 (165

- 4 ) Fish

bioconcentration (None) (N/A) No Study waived, due to chloropicrin’s low K

ow value

850.6100 Environmental chemistry

methods and

associated independent laboratory

validation (None) (N/A) Yes ECM and ILV studies are needed

for methods in air and water to support field volatility studies and aquatic toxicity studies.

835.4 3 00: Aerobic Aquatic Metabolism with Chloropicrin: An aerobic aquatic metabolism study with chloropicrin is necessary for risk assessment . This study will

enable the determination of chloropicrin’s residence time in water to address the potential length and intensity of exposure of aquatic species to chloropicrin. The DT 50 and residence time from this study will be used quantitatively in PRZM/EXAMS surface

water acute EEC calculat ions. Since volatilization is expected to be the dominate loss route and sorption to sediment is expected to be minimal, this study should only measure chloropicrin concentrations in water and in the headspace. However, known degradates should be quantif ied to recover and track the complete material balance over the course of the study.

11.2. Effects

Table 11 and Table 12 identify ecological effects studies by MRID that offer data for

each guid eline requirement, as well as study classifications and whether or not further data are needed in order to support risk assessment. Rationale for the additional data requested is presented below the tables where further explanation is needed

. EFED

recomm ends requesting the following studies to assess the environmental risks associated

with the use of chloropicrin for soil fumigation :

• Aquatic

o 850.4 5 00

– Aquatic non

- vascular plant studies

• Terrestrial

o 850.4100

– Seedling emergence study

o 850.4150

– Vegetative vigor vapor exposure study with additional species*

o Non

- guidelin e

– Avian acute inhalation study with bobwhite quail *

o Non

- guideline

– Acute h oney bee vapor exposure study *Page 29 of 62 *A protocol should be submitted to the Agency for approval prior to init iating the study.

No additional environmental toxicity data is needed to further assess the antimicrobial uses of chloropicrin.

Table 11 . Submitted Aquatic Ecological Effects Data for Chloropicrin

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

850.1010 Freshwater

invertebrate acute toxicity 4844240 1 Acceptable No

--

4710210 1 Supplemental

00130704 Supplemental

850.1025

850.1035 Saltwater

invertebrate acute toxicity 48442404 Supplemental No

--

48442403 Acceptable

850.1075 Freshwater

fish acute toxicity 48442406 Acceptable No

--

48442405 Acceptable

47102103 Supplemental

47102102 Supplemental

TN 0439 Supplemental

TN 0425 Supplemental

850.1075 Saltwater fish acute toxicity 48442402 Acceptable No

--

850.1300 Freshwater

invertebrate life cycle (None) (N/A) No C hronic exposure to aquatic organisms is not anticipated as

c hloropicrin is expected to be short

lived in the water column

.
850.1350 Saltwater

invertebrates life cycle (None) (N/A) No

--

850.1400 Freshwater

fish early

- life

stage (None) (N/A) No C hronic exposure to aquatic organisms is not anticipated as

c hloropicrin is expected to be short

lived in the water column

.Page 30 of 62 OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

850.1400 Saltwater fish early

- life

stage (None) (N/A) No

--

850.1500 Fish life cycle (None) (N/A) No

--

850.4400 Aquatic plant growth:

Tier II

vascular plants 48442801 Acceptable No

--

850.4500 Aquatic Plant

Growth: Tier II algae (None) (N/A) Yes Chloropicrin is highly soluble and therefore aquatic plant exposure is likely. Guideline compliant

studies are needed for a full suite

of non

- vascular aquatic plants ( i.e.

, green algae ( Pseudokirchneriella subcapitata ), blue

- green algae ( Anabaena flos

- aquae ), a f reshwater diatom ( Navicula pelliculosa ), and a m arine diatom ( Skeletonema costatum ) ).

Table 12 . Submitted Terrestrial Ecological Effects Data for Chloropicrin

OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

850.2100 Avian oral toxicity (None) (N/A) No Avian oral exposure via drinking water is a pathway of

concern ; however, assessment

of risk via inhalation is expected to be protective.

850.2200 Avian dietary toxicity (None) (N/A) No Avian d ietary exposure is not expected to be a significant exposure pathway

.
850.2300 Avian reproduction (None) (N/A) No Chronic avian inhalation toxicity data would be useful for evaluating chronic risk to birds. However, no study is requested at this time due to feasibility considerations. A weight of evidence approach

will be used to evaluate potential chronic risk to avian species.Page 31 of 62 OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

Non

guideline Avian

inhalation toxicity 48442803 Supplemental Yes Inhalation is the primary exposure pathway of concern for chloropicrin to terrestrial

animals

. A 4

- hr a cute avian

inhalation stud y on bobwhite quail is needed to establish an LC 50 . The previously submitted study uses a sub

chronic 5

- day exposure at sub

lethal exposure levels. A

p rotocol should be submitted to the agency prior to beginning the study. See additional justification below.

850.3020 Honey bee

acute contact toxicity 48442407 Acceptable No

--

850.3030 Honey bee

residue on foliage (None) (N/A) No

--

850.3040 Field testing

for pollinators (None) (N/A) No

--

Non

guideline Acute honey bee vapor

exposure study (None) (N/A) Yes Exposure to vapor is the primary pathway of concern for

non

- target terrestrial

invertebrates. A protocol

should be submitted to the agency prior to beginning the study. See additional justification below.

850.4100 S eedling

emergence 48442802 Supplemental Yes Soil exposure of seedlings to chloropicrin via runoff is a potential concern. The submitted study uses a vapor exposure pathway. Registrants are encouraged to contact the Agency regarding test

considerations prior to study

initiation.Page 32 of 62 OCSPP

Guideline Data Requirement Submitted

Studies (MRID) Study

Classifications Are

additional

data needed

for risk

assessment? Justification

850.4150 V egetative vigor 48442802 Supplemental Yes The submitted study tests effects of chloropicrin vapor on 4 dicot and 2 monocot species.

Effects were seen at the lowest

concentra tion tested. Testing

of a dditional species is needed to meet the guideline requirement of 6 dicots and 4

monocots and to establish a

clear NOAEC for use in risk

assessment

. A protocol should be submitted to the agency prior to beginning the study. See additional justification

below.

870.1300 Mammalian

acute
inhalation toxicity 45117902 Acceptable No

--

Guideline Number: N/A (Non

- Guideline Study) Study Title: Acute Avian Inhalation Rationale for Requiring the Data

Volatilization is the major route of dissipation for chloropicrin

. Therefore, to assess acute risks of chloropicrin to birds , EFED recommends that the Agency require a non

guideline acute avian inhalation exposure study for chloropicrin with bobwhite quail , to
be conducted in lieu of the 850.2100 requirement for acute avian oral toxici ty studies

. Practical Utility of the Data

How will the data be used? The acute avian inhalation data are needed to asses potential acute risks to birds

associated with th e inhalation route of exposure. Results of this study would be used to

calculate acute risk quotient s for birds from exposure to chloropicrin and to identify whether current labeling is appropriate and whether further mitigation is necessary. The data will allow the Agency to better assess the risks to these organisms, including

the l ikelihood of potential risks to endangered species, either by direct effects or by indirect effects such as reducing food sources to listed predators and scavengers.

How could the data impact the Agency’s future decision

- making? If future ecological risk assessments are performed without these data, the Agency would have to presume risk to non

- target birds, reptiles, and terrestrial

- phase amphibians, including listed species, from use of chloropicrin. Therefore, use of chloropicrin and its formulated prod ucts may need to be restricted in areas where these taxa could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in mitigating potential risks and could result in use restrictions for chloropicrin that arePage 33 of 62 unnece ssarily severe. If future endangered species risk assessments are performed without these data, the Agency would have to assume that chloropicrin "may affect” birds directly and other endangered species i ndirectly through loss of prey. The lack of

these da ta will limit the flexibility the Agency and registrants have in complying with the Endangered Species Act and could result in inappropriate mitigation measures.

Guideline Number: N/A (Non

- Guideline Study) Study Title: Acute Honey Bee Vapor Exposure Study Rationale for Requiring the Data Due to the fate properties of fumigants, in particular their high volatility, it is expected that honey bees and other insect pollinators will be exposed t o fumigants in the vapor phase. Neither of the standard Tier I toxicity studies with honey bees ( i.e., acute contact or acute oral toxicity study for honey bees) account for exposure to vapor phase pesticides. Therefore, to assess risks of chloropicrin to bees, EFED recommends that the Agency require a non

- guideline acute honey bee vapor exposure study for chloropicrin

, to be conducted in lieu of the newly proposed requirements for oral toxicity tests including adult and larval honey bees. Practical Utility of the Data

How will the data be used? Data from an acute honey bee vapor exposure study will be used to determine the potential for chloropicrin to affect non

- target terrestrial invertebrates in the terrestrial environment. Of particular interest is quantification of a toxicity e ndpoint, i.e., a 4

- hour

LC 50 , that can be used to derive risk quotients. In the absence of vapor exposure data specific for honey bees, risk to terrestrial invertebrates, including listed species, will be

assumed , and it will be impossible to determine how far from a treated site risks to

terrestrial invertebrates remain above concern levels.

How could the data impact the Agency’s future decision

- making? If future ecological risk assessments are performed without these data, the Agency would have to pres ume risk to non

- target terrestrial invertebrates, including honey bees, from

use of chloropicrin . Therefore, use of chloropicrin and its formulated products may need to be restricted in areas where terrestrial invertebrates, including honey bees, could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in mitigating potential risks and cou ld result in use restrictions for chloropicrin that are unnecessarily severe.

Guideline Number: 850.4150 (modified) Study Title: Vegetative Vigor Rationale for Requiring the Data Due to the fate properties of fumigants, in particular their high volatility, it is expected

that plants will be exposed to fumigants in the vapor phase. A vegetative vigor study with vapor exposure to chloropicrin was previously submitted to the Agency (M RID 48442802). This study tested 4 dicot and 2 monocot species. Effects were seen at the

lowest concentration tested , below previously modeled air exposure concentrations . The vegetative vigor guideline requires testing of 6 dicot and 4 monocot species. Th erefore, testing of additional species is requested. Additionally, the study protocol should providePage 34 of 62 justifications for the exposure period and test concentrations used . Justification for these

parameters was not provided in the previous study report.

Pra ctical Utility of the Data

How will the data be used?

Data from a vegetative vigor vapor exposure study will be used to determine the potential for chloropicrin to affect non

- target terrestrial plants . Of particular interest is quantification of toxicity endpoint s
, i.e., a NOAEC or EC 05 and an E C 25 that can be used to derive risk quotients for listed and non

- listed species, respectively . In the absence of

vapor exposure toxicity data for additional terrestrial plant species

, the lowest endpoints from the previously submitted study will be used in risk assessment and the resulting uncertainty in risk estimation will be identified.

How could the data impact the Agency’s future decision

- making? If future ecological risk assessments are performed wit hout these data, the Agency may have to presume risk to non

- target terrestrial plants in families that were not tested

, including listed species , from use of chloropicrin . Therefore, use of chloropicrin and its formulated products may need to be restricted in areas where terrestrial plants could be exposed. The lack of these data will limit the flexibility the Agency and registrants have in mitigating potential risks and could result in use restrictions for chloropicrin that are unnecessarily severe.

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Continent Ecology Division (MED). http://cfpub. epa.gov/ecotox/

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.

USEPA. 2009 a

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Yvon , S.A . and J.H. Butler. 1996. An Improved Estimate of the Oceanic Lifetime of Atmospheric CH3Br. Geophysical Res. Lett. 23:53

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MRID Citation Environmental Fate and Product Chemistry Studies

05007865 Moilanen, K.W.; Crosby, D.G.; Humphrey, J.R.; Giles, J.W. (1978) Vapor

- phase photodecomposition of chloropicrin (trichloronitromethane). Tetrahedron 34(22):3345

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05014376 Harton, E.E., Jr.; Rawl, R.R. (1976) Toxicological and skin corrosion testing of selected hazardous materials. Office of Hazardous Materials Ope rations, Department of Transportation, Washington, D.C. NTIS PB

- 264 975.

4147860 1 Olsen, G.; Lawrence, L. (1990) An a erobic Metabolism of (14 C)| Chloropicrin in Sandy Loam Soil: Lab Project Number: PTRL REPORT NO. 1232: PTRL PROJECT NO. 329. Unpublished study prepared by Pharmacology and Toxicology Research Lab. 46 p.

42900201 Moreno, T.; Lee, H. (1993) Photohydrolysis of Chloropicrin: Lab Project Number: BR389.1:93. Unpublished study prepared by Bolsa Research Associates, Inc. 98 p.

43022401 Chang, T. (1989) Hydrolysis Study with Chloropicrin as a Function of pH at 25 Degrees C: Lab Project Number: B.R. #51:89. Unpublished study prepared by Bolsa Research Associates. 33 p.Page 37 of 62 MRID Citation

43085101 Ivancovich, A. (1987) Chloropicrin

-- Field Dissipation Study: Lab Project Number: BR11:87.1. Unpublished study Prepared by Bolsa Research Associates. 144 p.

43613901 Hatton, C.; Shepler, K.; Ruzo, L. (1995) Aerobic Soil Metabolism of (carbon 14)

- Chloropicrin: Lab Project Number: 448W

- 1: 448W. Unpublished study prepared by PTRL West, Inc. 196 p.

43759301 Hatton, C.; Shepler, K.; Ruzo, L. (1995) Anaerobic Aquatic Metabolism of (Carbon 14) Chloropicrin: Lab Project Numbers: 449W

- 1: 449W. Unpublished study prepared by PTRL West, Inc. 200 p.

43798601 Skinner, W.; Jao, N. (1995) Laboratory Volatility of (carbon 14) Chloropicrin: Lab Project

Number: 450W

- 1: 450W. Unpublished study prepared by PTRL West, Inc. 99 p.

44149201 Beard, K.; Murphy, P.; Fontaine, D.; et al. (1996) Monitoring of Potential Worker Exposure, Field Flu x, and Off

- Site Air Concentration During Chloropicrin Field Application: (Final Report): Lab Project Number: HEH 160: RAM

- 10

- 050: F95059

- 527. Unpublished study prepared by The Dow Chemical Co. 701 p.

44191301 Skinner, W. (1996) Soil Column Leaching of (carbon

- 14) Chloropicrin in Four Soil Types: Lab Project Number: 587W

- 1: 587W. Unpublished study prepared by PTRL West, Inc. 230 p.

474560 0 1 Gillis, M. Smith. G. (2002) Chloropicrin Emissions and Offsite Drift from Tarped and

Non

- tarped Fields Treated by Drip Irrigation Application Method . TriCal, Inc. Report no. TC350. 95pp.

45112901 Knuteson, J.; Dolder, S. (2000) Field Volatility of 1,3

- Dichloropropene and Chloropicrin from Shallow Drip Irrigation Application of Telone C

- 35 (InLine ) to Strawberry Beds Covered with VIF Tarp: Lab Project Number: 980070.01. Unpublished study prepared by Dow AgroSciences LLC. 331 p.

45112902 van Wesenbeck, I.; Phillips, A. (2000) Field Volatility of 1,3

- Dichloropropene and Chloropicrin from Surface Dri p Irrigation Application of InLine to Vegetable Beds Under Polyethylene Tarp: Lab Project Number: 990072. Unpublished study prepared by Dow AgroSciences LLC and Paragon Research. 304 p.

46420201 Rotondaro, A. (2004) Monitoring of Chloropicrin Emissions fr om Field and Greenhouse Drip Irrigation Applications, and Implied Worker Inhalation Exposure From Applications of Chloropicrin by Shank Injection, Drip Irrigation Systems and at Tree Replant Sites. Project Number: PRS02004, ML02/1044/CMT. Unpublished study prepared by Paragon Research Services, Morse Laboratories and Agvise Inc. 793 p.

47295202 Baker, F.; Arndt, T. (2007) Direct and Indirect Flux Determination of Iodomethane and Chloropicrin under Field Conditions Following Tarped/Raised Bed/Shallow Shank Injection of Midas 50:50 in Dover, FL. Project Number: 1595W, 1595W/1. Unpublished study prepared by PTRL West, Inc., Paragon Research Services and Pacific Ag Group. 707

p. 47295203 Baker, F.; Arndt, T. (2007) Direct and Indirect Flux Determination of Iod omethane and Chloropicrin Under Field Conditions Following Tarped/Raised Bed/Shallow Shank Injection of Midas 50:50 in Bainbridge, GA. Project Number: 1619W, 1619W/1. Unpublished study prepared by PTRL West, Inc, Paragon Research Services, Pacific Ag Group . 590 p.

47295204 Baker, F.; Arndt, T. (2007) Direct and Indirect Flux Determination of Iodomethane and Chloropicrin Under Field Conditions Following Tarped/Raised Bed/Shallow Shank Injection of Midas 50:50 in Hart Michigan. Project Number: 1646W, 1646W/1. Unpublished study prepared by PTRL West, Inc, Paragon Research Services, Pacific Ag Group. 590 p.

47576901 Ajwa, H.; Sullivan, D. (2008) Monitoring of Chloropicrin Field Emissions from Shank Applications at Shallow and Deep Injection Depths. Project Number: 200801. Unpublished study prepared by Sullivan Environmental Consulting and University of California, Davis. 191 p.Page 38 of 62 MRID Citation

47679301 Rotondaro, A. (2009) Direct Flux Determination of Chloropicrin Emissions from a Drip, Buried, Non

- Tarped Applicati on. Project Number: PRS08004. Unpublished study prepared by Paragon Research Services, PTRL West, Inc. and Agvise, Inc. 192 p.

47813901 Ajwa, H.; Sullivan, D.; Chellemi, D. (2009) Monitoring 1,3

- Dichloropropene, Chloropicrin and Methyl Isothiocyanate Emis sions from Shank Applications at Three Sites Near Duette, Florida. Project Number: 2009A. Unpublished study prepared by University of California, Sullivan Environmental Consulting and JRF America. 114 p.

48006001 Ajwa, H.; Sullivan, D. (2010) Monitoring Methyl Bromide and Chloropicrin Field Emissions from Shank Applications at Shallow and Deep Injection Depths . Methyl Bromide Industry Panel, LLC. Study ID 200901. 574p.

48033801 Rotondaro, A.; Rotondaro, M. (2010) Direct Flux Determination of Chloropicrin Emissions from Shank, Bedded, Non

- Tarped Applications. Project Number: PRS09006, 1978W. Unpublished study prepared by PTRL West, Inc. and Paragon Research Services and Agvise Laboratories, Inc. 229 p.

48085701 Ajwa, H.; Sullivan, D.; Chellemi, D. (2010) Monitoring 1,3

- Dichloropropene and Cloropicrin Emissions from Solid

- Tarp Shank Injections at Two Sites Near Fort Pierce, Florida. Project Number: 2009H. Unpublished study prepared by University of California and Sullivan Environmental Consulting. 146 p.

4 8087401 Ajwa, H. (2010) Chloropicrin Flux Rates for Drip Fumigation with PE and TIF Tarps, Water Seal and KTS at Salinas, California in September 2007. Project Number: 2007/D. Unpublished study prepared by University of California and Sullivan Environmenta l Consulting. 100 p.

48107601 Ajwa, H.; Sullivan, D. (2010) Monitoring of Methyl Bromide and Chloropicrin Field Emissions from Shank Applications (Bedded and Broadcast) and a Methyl Bromide Hot

Gas Application under Totally Impermeable Film. Project Numbe r: HA201001. Unpublished study prepared by University of California and Sullivan Environmental Consulting. 219 p. Ecological Effects Studies

TN 0439 McCann, J. (1972) Fish Toxicity Laboratory Report (#439) Chloropicrin Fumigant and Bluegill Sunfish (Lepomis macrochirus). Unpublished Study Performed by Animal Biology Laboratory, Beltsville, Maryland. Laboratory Project No. 439. Study Sponsor not Reported. Study Completed January 22, 1972.

TN 0425 McCann, J. (1971) Fish Toxicity Laboratory Report (#42 5) Chloropicrin Fumigant and Rainbow Trout (Salmo gairdneri). Unpublished Study Performed by Animal Biology Laboratory, Beltsville, Maryland. Laboratory Project No. 425. Study Sponsor not Reported. Study Completed December 5, 1971.

00130704 Cody, W.; Shem a, R. (1983) Acute Toxicity of Chloropicrin to Daphnia pulex. (Unpublished study received May 9, 1983 under unknown admin. no.; prepared by NUS Corp., submitted by Chloropicrin Consortium, West Lafayette, IN; CDL:251027

- B)

42740601 York, R. (1993) Inhalation Developmental Toxicity Study in New Zealand White Rabbits: Chloropicrin: Lab Project Number: 656

- 009. Unpublished study prepared by International Research and Development Corp. 179 p.

43391901 Schardein, J. (1994) Two Generation Inhalation Repr oduction/Fertility Study in Rats: Chloropicrin: Lab Project Number: 656

- 011. Unpublished study prepared by International Research & Development Corp. 703 p.

45117902 Hoffman, G. (1999) Chloropicrin: An Inhalation Toxicity Study in the Rat via Whole

Body Exposure: Lab Project Number: 99

- 5387. Unpublished study prepared by Huntingdon Life Sciences. 202 p.

47102101 Flatman, D. (2004) Chloropicrin: Acute Toxicity to Daphnia magna. Project Number: RDB/019/033845. Unpublished study prepared by Huntingdon Life Sciences, Ltd. 35 p.

47102103 Flatman, D. (2004) Chloropicrin: Acute Toxicity to Fish (Bluegill Sunfish). Project Number: RDB/006/033843. Unpublished study prepared by Huntingdon Life Sciences, Ltd. 37 p.Page 39 of 62 MRID Citation

47102102 Flatman, D. (2004) Chloropicrin: Acute Toxicity to Fish (Rainbow Trout). Project Number: RDB/005/033842. Unpublished study prepared by Huntingdon Life Sciences, Ltd. 34 p.

48442401 Sayers, L. (2010) Chloropicrin

- Acute Toxicity to Water Fleas, (Daphnia magna) Under

Flow

- Through Conditions. Pr oject Number: 3140/6112. Unpublished study prepared by Springborn Smithers Laboratories. 56 p.

48442402 Sayers, L. (2010) Chloropicrin

- Acute Toxicity to Water Fleas, (Daphnia magna) Under

Flow

- Through Conditions. Project Number: 3140/6112. Unpublished study prepared by Springborn Smithers Laboratories. 56 p.

48442403 Sayers, L. (2010) Chloropicrin

- Acute Toxicity to Mysids (Americamysis bahia) Under

Flow

- Through Conditions. Project Number: 3140/6113. Unpublished study prepared by Springborn Smithers Laboratories. 55 p.

48442404 York, D. (2010) Chloropicrin

- Acute Toxicity to Eastern Oyster (Crassostrea virginica)

Under Flow

- Through Conditions. Project Number: 3140/6114. Unpublished study prepared by Springborn Smithers Laboratories. 60 p.

48442405 Sayers, L. (2010) Chloropicrin

- Acute Toxicity to Rainbow Trout (Oncorhynchus mykiss)

Under Flow

- Through Co nditions. Project Number: 3140/6110. Unpublished study prepared by Springborn Smithers Laboratories. 54 p.

48442406 Sayers, L. (2010) Chloropicrin

- Acute Toxicity to Bluegill Sunfish (Lepomis macrochirus) Under Flow

- Through Conditions. Project Number: 31 40/6109. Unpublished study prepared by Springborn Smithers Laboratories. 56 p.

48442407 Patnaude, M. (2011) Chloropicrin

- Acute Contact Toxicity Test with the Honey Bee (Apis mellifera). Project Number: 3140/6117. Unpublished study prepared by Springborn Smithers Laboratories. 36 p.

48442801 Wilby, J. (2009) Chloropicrin: Higher Plant (Lemna) Growth Inhibition Test. Project Number: SXC0023. Unpublished study prepared by Huntingdon Life Sciences, Ltd. 39 p.

48442802 Weinberg, J. (2009) Toxicity of Chloro picrin to Six Plant Species: Corn, Soybean, Annual Ryegrass, Oilseed Rape, Cucumber & Sunflower: Final Report. Project Number: WIL/697004. Unpublished study prepared by WIL Research Laboratories, Inc., Ohio State University and Agvise Laboratories, Inc. 52 7 p.

48442803 Weinberg, J. (2009) A 5

- Day Whole

- Body Inhalation Toxicity Study of Chloropicrin in Northern Bobwhite Quail: Final Report. Project Number: WIL/697002. Unpublished study prepared by WIL Research Laboratories, Inc. and Biotechnics, Inc. 563 p.

Antimicrobial Use Studies

00013177 Cooper, P.A. (1973) The Movement of Chloropicrin Vapor in Wood to Control Decay. Master's thesis, Oregon State Univ., Dept. of Forest Products. (Unpublished study received Apr 23, 1974 under 5316

- 17; submitted by Namco Chemicals, Inc., San Jose, Calif.;

CDL:024054

- C)

00013189 Cooper, P.A. (1973) The Movement of Chloropicrin Vapor in Wood to Control Decay. Master's thesis, Oregon State Univ., Dept. of Forest Products. (Unpublished study received Apr 23, 1974 under 5316

- 17; submitted by Namco Chemicals, Inc., San Jose, Calif.;

CDL:024054

- C)Page 40 of 62 Appendix A. SIP and STIR Results

SIP The Screening Imbibition Program (SIP version 1.0; 6/15/2010) was used to calculate an upper bound estimate of exposure via drinking water using the solubility of chloropicrin (1

, 612 mg/L). T he most sensitive acute mammalian toxicity endpoint (rat, LD 50 =37.5 mg/kg

- bw) for chloropicrin was used. There are no acute or chronic avian dietary toxicity data or chronic mammalian dietary toxicity data to use in the model. Drinking

water exposure to chloropicrin may be a pathway of concern for bo th avian and mammalian species . Results are presented in the tables below

.

SIP Avian Results for Chloropicrin

Parameter Acute Chronic
Upper bound exposure (mg/kg

- bw) 1,306 1,306
Adjusted toxicity value (mg/kg

- bw) N o data N o data

Ratio of exposure to acute toxicity N o data N o data

Conclusion* Due to insufficient data, risk cannot be precluded Due to insufficient data, risk cannot be precluded

SIP Mammalian Results for Chloropicrin

Parameter Acute Chronic
Upper bound exposure (mg/kg

- bw) 277 277
Adjusted toxicity value (mg/kg

- bw) 28.8 No data
Ratio of exposure to toxicity 9.61 No data

Conclusion* Exposure through drinking water alone is a potential

concern for mammals Due to insufficient data, risk cannot be precluded

*Conclusions are for drinking water exposure alone. This does not combine all routes of exposure. Therefore, when aggregated with other routes ( i.e. , diet, inhalation, dermal), pesticide exposure through drinking water may contribute to a total exposure that has potential for effects to non

- target animals.

STIR The Screening Tool for Inhalation Risk (STIR version 1.0; 11/23/2010) w as used to calculate upper bound estimates of chloropicrin exposures via in halation. The exposure pathway assessed is vapor phase inhalation. Droplet inhalation is not applicable because there are no spray applications of chloropicrin. Model inputs for chloropicrin included molecular weight ( 164.4 g/mole), vapor pressure (2.38 mmHg ), highest application rate ( 350 lb a.i./A) and most sensitive acute oral and inhalation mammalian toxicity endpoints (rat, LD 50 = 37.5 mg/kg

- bw and 4 hr inhalation LC 50 0.114 mg/L, respectively). There are no acute avian dietary or inhalation toxicity data to use in this model. V apor inhalation was determined to be a potential pathway of concern for avian and mammalian species.

STIR Avian (0.020 kg) Results for Chloropicrin

Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.11E+ 05

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 2.65E+04

Adjusted Inhalation LD 50 (mg/kg) No dataPage 41 of 62 Ratio of Vapor Dose to Adjusted Inhalation LD 50 No data Insufficient data

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) Not applicable

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 Not applicable Not applicable

STIR Mammalian (0.15 kg) Results for Chloropicrin

Maximum Vapor Concentration in Air at Saturation (mg/m 3 ) 2.11+ 05

Maximum 1

- hour Vapor Inhalation Dose (mg/kg) 3.33E+04

Adjusted Inhalation LD 50 (mg/kg) 6.79 E+0 0

Ratio of Vapor Dose to Adjusted Inhalation LD 50 4.90E+03 Proceed to Refinements

Maximum Post

- treatment Spray Inhalation Dose (mg/kg) Not applicable

Ratio of Droplet Inhalation Dose to Adjusted Inhalation LD 50 Not applicable Not applicablePage 42 of 62 Appendix B

. Field Volatility Study Summaries

Direct and Indirect flux determination of Iodomethane and Chloropicrin under

Field Conditions Following Tarped/Raised Bed/ Shallow Shank Injection Application of MIDAS 50:50 in Dover, FL (MRID 47295202 )

MIDAS 50:50 was applied via a tarped, shank injection to a field measuring 3 30 feet ( 101 meters) by 330 feet (10 1 meters) at a rate of 144.8 pounds ai per treated acre in January 31, 2007

. The field was oriented in a north

- south direction. A 0.0013 inch thick metalized white tarpaulin ( Canslit Inc .) was placed over the application plot. Application began at 11 : 24 am and was complete d by 3 : 0 1 pm

. Eight samplers were placed evenly

around the field at a distance of 60 feet to measure the amount of MIDAS 50:50 in the air around the field. Samplers were placed at a height 5 feet above the ground. Additionally, a sample mast was placed in the c enter of the field and samples collected at five different heights. Meteorological measurements were also made onsite. Estimated flux rates for the first 5 days are provided in Table 1.

Table 1. Flux Rates Dover, FL Study

Period Date/Time Flux Estimation Technique

Indirect Aerodynamic

Flux ( μ g/m2

- s) Reasoning Flux ( μ g/m2

- s) Reg. 1 Est. 2 Est. Reg. Est. Chloropicrin

1 Day 0 11:00

- 14:00

11.70 13.57 Slope, no intercept 1.24 1.63

2 Day 0 14:00

- 17:00

6.76 4.65 Slope, no intercept 0.30 0.37

3 Day 0 17:00

- 19:00

6.37 3.25 Slope, no intercept 0.22 0.29

4 Day 0 19:00

- 7:00

0.78 1.09 Slope, no intercept 0.64 0.78

5 Day 1 7:00

- 19:00 1.22 1.35 Slope 0.60 0.67

6 Day 1 19:00

- 7:00

2.87 1.96 Slope, no intercept 0.47 0.55

7 Day 2 7:00

- 19:00 0.81 0.57 Slope 0.33 0.39

8 Day 2 19:00

- 7:00

0.27 0.38 Slope, no intercept 0.18 0.23

9 Day 3 7:00

- 19:00 0.35 0.48 Slope 0.10 0.12

10 Day 3 19:00

- 7:00 0.28 0.33 Slope 0.04 0.06

11 Day 4 7:00

- 19:00 0.37 0.45 Slope 0.05 0.07

12 Day 4 19:00

- 7:00 0.19 0.22 Slope 0.05 0.06
1. Reg.

– Registrant estimated flux rates.

2. Est.

– Versar estimated flux rates.Page 43 of 62 Direct and Indirect Flux Determination of Iodomethane and Chloropicrin

u nder Field Conditions Following Tarped/Raised Bed/Shallow Shank Injection Application of MIDAS 50:50 in Bainbridge, GA ( MRID 47295203 )

MIDAS 50:50 was applied via a tarped, shank injection to a field measuring 3 30 feet ( 101 meters) by 330 feet (10 1 meters) at a rate of 154.8 pounds ai per treated acre o n March 21, 2007

. The field was oriented to the northeast. A 0.00125 inch thick tarpaulin, Hytiblock 7 black film (Polygrow Inc.) was placed over the application plot. Application began at 09:46 am and was complete d by 12 : 46 pm

. Eight samplers were placed evenly

around t he field at a distance of 60 feet to measure the amount of MIDAS 50:50 in the air around the field. Samplers were placed at a height 5 feet above the ground. Additionally, a sample mast was placed in the center of the field and samples collected at

five different heights. Meteorological measurements were also made onsite. Estimated flux rates for the first 5 days are provided in Table 2.

Table 2. Flux Rates Bainbridge, GA Study

Period Date/Time Flux Estimation Technique

Indirect Aerodynamic

Flux ( μ g/m2

- s) Reasoning Flux ( μ g/m2

- s) Reg. 1 Est. 2 Est. Reg. Est. Chloropicrin

1 Day 0 10:00

- 14:00 4 0.422 0.940 Ratio of

averages 0.054

- 0.003

2 Day 0 14:00

- 17:00 0.323 0.175 Slope, no intercept 0.347 0.373

3 Day 0 17:00

- 20:00 0.322 0.238 Slope 0.370 0.370

4 Day 0 20:00

- 8:00 0.272 0.292 Slope 0.189 0.190

5 Day 1 8:00

- 20:00 0.516 0.465 Slope, no intercept 0.354 0.354

6 Day 1 20:00

- 8:00 0.101 0.068 Slope 0.042 0.042

7 Day 2 8:00

- 20:00 0.096 0.070 Slope, no intercept 0.096 0.096

8 Day 2 20:00

- 8:00 0.022 0.023 Slope, no intercept 0.008 0.010

9 Day 3 8:00

- 20:00 0.030 0.246 Slope 0.018 0.011

10 Day 3 20:00

- 8:00 0.015 0.012 Slope, no intercept 0.002 0.001

11 Day 4 8:00

- 20:00 0.017 0.020 Slope, no intercept 0.008 0.065

12 Day 4 20:00

- 8:00 0.062 0.077 Ratio of

averages 0.003 0.002
1. Reg.

– Registrant estimated flux rates.

2. Est.

– Versar estimated flux rates.

3. All on

- site samplers below LOQ.Page 44 of 62 Direct and Indirect Flux Determination o f Iodomethane and Chloropicrin

u nder Field Conditions Following Tarped/Raised Bed/Shallow Shank Injection Application of MIDAS 50:50 in Hart, MI (MRID 47295204 )

MIDAS 50:50 was applied via a tarped, shank injection to a field measuring 3 30 feet ( 101 meters) by 330 feet (10 1 meters) at a rate of 159.7 pounds ai per treated acre o n May 17, 2007

. The field was oriented in a north

- south direction. A 0.00125 inch thick XL Black Blockade ( P liant Corp.) was placed over the application plot. Application began at 10 :0 7 am and was complete d by 1:14 pm

. Eight samplers were placed evenly

around the field at a distance of 60 feet to measure the amount of MIDAS 50:50 in the air around the field. Samplers were placed at a height 5 feet above the ground. Additionally, a sample mast wa s placed in the center of the field and samples collected at five different heights. Meteorological measurements were also made onsite. Estimated flux rates for the first 3 days for chloropicrin are provided in Table 3.

Table 3. Flux Rates Hart, MI Study

Period Date/Time Flux Estimation Technique

Indirect Aerodynamic

Flux ( μ g/m2

- s) Reasoning Flux ( μ g/m2

- s) Reg. 1 Est. 2 Est. Reg. Est. Chloropicrin

1 Day 0 1 1 :00

- 1 3 :00 0.885 0.96 Slope, no intercept 0.117 0.115

2 Day 0 13 :00

- 1 6 :00 0.291 0.12 Slope, no intercept 0.03 0.02

3 Day 0 16 :00

- 19 :00 NA NA NA NA NA

4 Day 0 19:00

- 7:00 0.008 0.006 Slope 0.009 0.009

5 Day 1 7:00

- 19:00

0.022 0.026 Slope, no intercept 0.025 0.026

6 Day 1 19:00

- 7:00

0.025 0.034 Slope, no intercept 0.009 0.007

7 Day 2 7:00

- 19:00

0.009 0.017 Slope, no intercept 0.014 0.013

8 Day 2 19:00

- 7:00 0.017 0.008 Slope 0.002 0.002
1. Reg.

– Registrant estimated flux rates.

2. Est.

– Versar estimated flux rates.

NA = not assessed. Insufficient data were available to estimate flux rates for these periods.

Flux Rate Estimation of Chloropicrin Emissions from a Drip, Buried, Non

Tarped Application (MRID 47679301)

C hloropicrin was applied via a buried, non

- tarped drip irrigation application of emulsifiable concentrate of chloropicrin to a field in Yuma AZ. The plot measured 295

feet north to south and 301 feet east to west with beds 84 inches wide. Tri

- Clor EC wasPage 45 of 62 applied at rate of 297.5 pounds per treated acr e in November 200 8 . Application began

at 8 :0 0 am on November 3 rd and was complete d by 16:28

. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, 150, and 180 centimeter heights for aerodynamic flux estimates. Estimat ed flux rates for the first 48 hours are provided in Table 4.

Table 4. Flux Rates Obtained from Yuma, AZ Study

Period Date/Time Registrant Flux (μg/m2

- s) Versar Flux (μg/m2

- s)

1 11/3/2008 08:00

- 13:00 2.660 3.426

2 11/3/2008 13:00

- 19:00 39.300 46.998

3 11/3/2008 19:00

- 01:00 26.800 32.650

4 11/4/2008 01:00

- 07:00 9.720 11.022

5 11/4/2008 07:00

- 13:00 11.800 14.960

6 11/4/2008 13:00

- 19:00 8.150 9.689

7 11/4/2008 19:00

- 01:00 5.730 6.601

8 11/5/2008 01:00

- 07:00 5.530 6.873

9 11/5/2008 07:00

- 18:00 5.590 6.850

10 11/5/2008 18:00

- 07:00 1.360 1.783

11 11/6/2008 07:00

- 18:00 1.390 1.769

12 11/6/2008 18:00

- 07:00 0.537 0.674

13 11/7/2008 07:00

- 18:00 0.407 0.501

14 11/7/2008 18:00

- 07:00 0.119 0.155

15 11/8/2008 07:00

- 18:00 0.181 0.234

16 11/8/2008 18:00

- 07:00 0.040 0.053

17 11/9/2008 07:00

- 18:00 0.000 0.000

18 11/9/2008 18:00

- 07:00 0.019 0.026

19 11/10/2008 07:00

- 18:00 0.000 0.000

20 11/10/2008 18:00

- 07:00 0.006 0.008

21 11/11/2008 07:00

- 18:00 0.046 0.063

22 11/11/2008 18:00

- 07:00 0.009 0.012

23 11/12/2008 07:00

- 18:00 0.000 0.000

24 11/12/2008 18:00

- 07:00 0.009 0.012

25 11/13/2008 07:00

- 18:00 0.000 0.000

26 11/13/2008 18:00

- 07:00 0.006 0.009

27 11/14/2008 07:00

- 18:00 0.000 0.000

28 11/14/2008 18:00

- 07:00 0.000 0.000

29 11/15/2008 07:00

- 18:00 0.000

- 0.110

30 11/15/2008 18:00

- 07:00 0.000 0.007

31 11/16/2008 07:00

- 18:00 0.000

- 0.097

32 11/16/2008 18:00

- 07:00 0.000 0.005

31 11/16/2008 07:00

- 18:00 2.660 3.426

32 11/16/2008 18:00

- 07:00 39.300 46.998Page 46 of 62 Field Volatility of 1,3

- Dichloropropene and Chloropicrin from Shallow Drip Irrigation Application of Telone C

- 35 (InLine) to Strawberry Beds Covered with VIF Tarp (MRID 45112901 )

Chloropicrin was applied via drip irrigation to two adjacent raised bed, tarped fields, one 4.42 acres and one 4.98 acres (7.52 treated acres), in Salinas Valley, CA at a rate of 70.5 pounds ai per acre in October, 1998 . Application began at 8:30 AM and was complete at
12:30 P M. A Hytibar © tarp was placed over the bed tops and sides of the application plot , but the inter

- bed furrows were not covered . Samplers were placed at a height 1.5

meters above the ground. Air samplers were also placed on a mast at the center of the two fields, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Flux estimates for the first 48 hours are provided in Table 5.

Table 5. Flux Rates Obtained from Salinas Valley, CA Study

Period Day/ Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 0

- 6 5.63

2 Day 0, Hours 6

- 12 14.85

3 Day 0, Hours 12

- 24 1.15

4 Day 1 , Hours 0

- 6 2.05

5 Day 1, Hour 6

- 12 4.37

6 Day 1, Hours 12

- 24 0.16

Field Volatility of 1,3

- Dichloropropene and Chloropicrin from Surface Drip Irrigation Application of Telone C

- 35 (InLine) to Vegetable Beds under Polyethylene Tarp (MRID 451129 02)

Chloropicrin was applied via drip irrigation to a raised bed, tarped field, 10.7 acres (4.33 treated acres), in Douglas, GA at a rate of 36.4 pounds ai per acre in April, 2000

. Application began at 12:30 P M and was complete at 5:30 P M. A standard polyethylene tarp was placed over the beds of the application plot. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature

measurements were also made at the center of the field

. Flux estimates for the first 48 hours are provided in Table 6

.

Table 6 . Flux Rates Obtained from Douglas, GA Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 0

- 5 7.33

2 Day 0, Hours 5

- 19 0.78Page 47 of 62 Period Day/Hour Flux Rate (ug/m 2

- s)

3 Day 0, Hours 19

- 24 3.42

4 Day 1 , Hours 0

- 5 6.58

5 Day 1 , Hours 5

- 19 0.11

6 Day 1, Hours 19

- 24 0.69

Monitoring of Potential Worker Exposure, Field Flux, and Off

- Site Air Concentration during Chloropicrin Application (MRID 44149201, Plot 1 )

Chloropicrin was applied via broadcast to an 8.0 acres, untarped field in Arizona at a rate
of 170.7 pounds ai per acre in April, 1995 . Application began at 7:18 A M and was complete at 12:45 P M. Samplers were placed at a height 1.5 meters above the ground. Air samplers were also pl aced on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature measurements were also made at the center of

the field

. Flux estimates for the fir st 48 hours are provided i n Table 7

.

Table 7 . Flux Rates Obtained from Arizona Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 6

- 11 42.7

2 Da y 0, Hours 11

- 17 180.3

3 Day 0, Hours 17

- 23 63.1

4 Day 0, Hour 23

– Day 1, Hour 5 49.6

5 Day 1 , Hour s 5

- 11 40.0

6 Day 1, Hours 11

- 17 59.9

7 Day 1, Hours 17

- 2 3 35.0

8 Day 1, Hour 23

– Day 2, Hour 5 18.9

9 Day 2, Hours 5

- 6 9.7

Monitoring of Potential Worker Exposure, Field Flux, and Off

- Site Air Concentration during Chloropicrin Application (MRID 44149201, Plot 2 )

Chloropicrin was applied to a raised bed, untarped field, 2.26 acres in Arizona at a rate of

85.6 pounds ai per acr e in April, 1995 . Application began at 10:43 A M and was complete at 2:12 P M. Samplers were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speedPage 48 of 62 and temperature measurements were also made at the center of the field

. Flux estimates for the first 48 hours are provided in Tab le 8

.

Table 8 . Flux Rates Obtained from Arizona Study

Pe riod Day/Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 3

– 7 114.1

2 Day 0, Hours 7

– 13 112.8

3 Day 0, Hours 13

– 19 36.0

4 Day 0, Hour 19

– Day 1, Hour 1 22.0

5 Day 1, Hours 1

- 7 9.5

6 Day 1 , Hours 7

- 13 8.4

7 Day 1, Hours 13

– 19 6.4

8 Day 1, Hours 19

– 24 3.0

9 Day 1, Hours 24

- 3 1.9

Monitoring of Potential Worker Exposure, Field Flux, and Off

- Site Air Concentration during Chloropicrin Application (MRID 44149201, Plot3 )

Chloropicrin was applied to a raised bed, tarped field, 5.9 acres (3.0 treated acres), in

Arizona at a rate of 188.7 pounds ai per acre in May, 1995 . Application began at 6:25

A M and was complete at 6:56 P M. A standard tarp was placed over the application plot

. Samplers were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature

measurements were also made at the center of the field

. Flux estimates for the first 48 hours are provide d in Table 9

.

Table 9 . Flux Rates Obtained from Arizona Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 13

– 18 28.4

2 Day 0, Hours 18

– 24 49.7

3 Day 1, Hours 0

- 6 99.5

4 Day 1 , Hours 6

- 12 131.7

5 Day 1 , Hours 12

- 18 142.1

6 Day 1 , Hours 1 8

- 24 57.3

7 Day 2 , Hour 0

- 6 58.8

8 Day 2 , Hours 6

- 12 29.6Page 49 of 62 9 Day 2, Hours 12

- 13 14.6

Monitoring of Potential Worker Exposure, Field Flux, and Off

- Site Air Concentration during Chloropicrin Application (MRID 44149201, Plot4 )

Chloropicrin was applied via broadcast to an 8.0 acres, tarped field in Arizona at a rate of

332.1 pounds ai per acr e in May, 1995 . Application began at 7:13 A M and was complete

at 11:55 A M. A standard tarp was placed over the application plot. Samplers were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast

at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature measurements were
also made at the center of the field

. Flux estimates for the first 48 hours are provided in Table 10

.

Table 10 . Flux Rates Obtained from Arizona Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 5

- 11 59.2

2 Day 0, Hours 11

- 17 19.6

3 Day 0, Hours 17

- 2 3 29.5

4 Day 0, Hour 2 3

– Day 1, Hour 5 211.0

5 Day 1 , Hour s 5

– 11 172.7

6 Day 1, Hours 1 1

– 17 30.2

7 Day 1, Hours 17

– 23 28.9

8 Day 1, Hour 23

– Day 2, Hour 5 134.2

Monitoring of Potential Worker Exposure, Field Flux, and Off

- Site Air Concentration during Chloropicrin Application (MRID 44149201, Plot5 )

Chloropicrin was applied via broadcast to an 8.4 acres, tarped field in Yakima, WA at a
rate of 343 pounds ai per acre in October, 1995 . Application began at 7:55 A M and was complete at 3:22 P M. A standard tarp was placed over the application plot and punched

toward s the end of Day 5 . Samplers were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux

estimates. W ind speed and temperature measurements were also made at the center of

the field

. Flux estimates for the highest 24

- hour period while tarped and the highest 24

- hour period after punching of the tarp are provided in Table 11

.Page 50 of 62 Table 11 . Flux Rates Obtained from Yakima, WA Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 1, Hour 23

– Day 2, Hour 5 5.7

2 Day 2, Hours 5

– 11 23.3

3 Day 2, Hours 11

– 17 8.3

4 Day 2 , Hour s 17

– 23 7.5

5 Day 5 , Hour 23

- Day 6, Hour 5 35.2

6 Day 6 , Hours 5

– 11 70.4

7 Day 6 , Hours 11

– 17 10.2

8 Day 6 , Hours 17

– 23 19.9

Monitoring of Potential Worker Exposure, Field Flux, and Off

- Site Air Concentration during Chloropicrin Application (MRID 44149201, Plot6 )

Chloropicrin was applied via broadcast to an 8.4 acres, tarped field in Bradenton, FL at a
rate of 346 pounds ai per acre in January, 1996 . Application began at 7:52 A M and was complete at 1:22 P M. A standard tarp was placed over the application plot and punched at the beginning of Day 6. Samplers were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature measurements were als o made at the center of

the field

. Flux estimates for the highest 24

- hour period while tarped and the highest 24

- hour period after punching of the tarp are provided in Table 12

.

Table 12 . Flux Rates Obtained from Bradenton, FL Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 1, Hour 23

– Day 2, Hour 4 30.2

2 Day 2, Hours 4

– 10 57.8

3 Day 2, Hours 10

– 16 21.7

4 Day 2 , Hour s 16

– 23 4.46

5 Day 5 , Hour 23

- Day 6, Hour 4 22.0

6 Day 6 , Hours 4

– 10 47.8

7 Day 6 , Hours 10

– 16 9.7

8 Day 6 , Hours 16

– 23 4.4Page 51 of 62 Chloropicrin Emissions and Offsite Drift from Tarped and Non

- tarped Fields Treated by Drip Irrigation Application Method (MRID 4745601 )

Chloropicrin was applied to two raised bed fields in Yumaz AZ, one tarped and one untarped, each approximately 4.4 acres in size and at a rate of 403 pounds ai per treated

acre in September, 1999 . Application on the tarped field began at 7:00 A M and was complete at 12:30 P M. Application on the untarped field began at 9:00 A M and was complete at 2:30 P M. Sampler s were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature me asurements were also made at the center of the field

. Flux estimates are provided in Tab le 13

.

Table 13. Flux Rates Obtained from Yuma AZ Study

Period Date Time Flux Rate (ug/m2

- s) Aerodynamic

Method Indirect

Method

Estimated Reported Estimated

Untarped Field

1 9/3/1999 9:00

- 13:00 0.11 0.1 4.06

2 9/3/1999 13:00

- 19:00 19.42 16.00 5.71

3 9/3/1999 19:00

- 6:00 7.69 8.00 14.07

4 9/4/1999 6:00

- 13:00 35.88 46.00 21.52

5 9/4/1999 13:00

- 19:00 41.53 46.00 4.56

6 9/4/1999 19:00

- 7:00 12.31 12.00 9.28

7 9/5/1999 7:00

- 13:00 1.85 2.00 4.14

8 9/5/1999 13:00

- 19:00 7.37 9.00 2.14

9 9/5/1999 19:00

- 6:00 4.35 4.00 1.17

10 9/6/1999 6:00

- 13:00 2.22 3.00 1.63

11 9/6/1999 13:00

- 19:00 1.12 1.00 0.74

12 9/6/1999 19:00

- 6:00 0.21 0.20 0.50

13 9/7/1999 6:00

- 13:00 0.14 0.10 1.84

14 9/7/1999 13:00

- 19:00 0.09 0.06 1.86

15 9/7/1999 19:00

- 7:00 0.32 0.30 4.86

16 9/8/1999 7:00

- 13:00 0.68 0.70 5.28

17 9/8/1999 13:00

- 20:00 0.06 0.07 0.28

18 9/8/1999 20:00

- 7:00 0.34 0.30 1.50

19 9/9/1999 7:00

- 13:00 0.06 0.07 0.63

20 9/9/1999 13:00

- 19:00 0.00 0.00 0.57 Tarped Field

1 9/7/1999 7:00

- 13:00 5.14 5.0 0.32

2 9/7/1999 13:00

- 19:00 15.71 16.0 0.30

3 9/7/1999 19:00

- 6:00 2.49 2.0 3.83

4 9/8/1999 6:00

- 13:00 2.36 2.0 0.60Page 52 of 62 Period Date Time Flux Rate (ug/m2

- s) Aerodynamic

Method Indirect

Method

Estimated Reported Estimated

5 9/8/1999 13:00

- 19:00 2.38 2.0 0.44

6 9/8/1999 19:00

- 7:00 0.36 0.4 0.25

7 9/9/1999 7:00

- 13:00 0.42 0.4 0.37

8 9/9/1999 13:00

- 19:00 0.80 0.8 9.41

9 9/9/1999 19:00

- 7:00 0.11 0.1 0.43

10 9/10/1999 7:00

- 13:00 0.22 0.2 0.60

11 9/10/1999 13:00

- 19:00 0.10 0.09 2.55

Monitoring of Chloropicrin Field Emissions from Shank Applications at Shallow and Deep Injection depths (MRID 47576901 )

Four field studies were conducted in Wasco, CA in May of 2008: one shank injection, broadcast tarped application, one shank injection, flatfume tarped application, and two shank injection, untarped applications, one at an injection depth of 12 inches and one at an injection depth of 18 inches.

For the shank injection, broadcast tarped application, chlor opicrin was applied to a one

acre field at a rate of 358 pounds ai per treated acr e . Application began at 7:47 A M and was complete at 8:23 A M. A 1

- mil polyethylene tarp was placed over the application plot and split on Day 6 and removed on Day 7. For th e flat fume, tarped application, chloropicrin was applied to a one acre field at a rate of 320 pounds ai per treated acr e

. Application began at 9:41 A M and was complete at 9:55 A M. A 1

- mil polyethylene tarp was placed over the application plot and split on Day 6 and removed on Day 7. For the shank injected, untarped application conducted at 12 inches, chloropicrin was applied to a

one acre field at a rate of 197 pounds ai per treated acr e . Application began at 11:10 A M and was complete at 11:35 AM. F or the shank injected, untarped application conducted at 18 inches, chloropicrin was applied to a one acre field at a rate of 321 pounds ai per

treated acr e . Application began at 12:18 P M and was complete at 1:00 PM.

Samplers were placed at a height 1 .5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 1, 2, 3, 6, and 10 feet heights for integrated horizontal flux estimates. Due to difficulties collecting the concentration samples at 10 feet, these samples were not used in the flux estimation. Wind speed and wind direction measurements were made at the center of the field

. Flux

estimates for all four sites are provided in Table 14

.Page 53 of 62 Table 14 . Flux Rates Obtained from Wasco, CA Study

Period Field 1 Field 2 Field 3 Field 4

Broadcast

Tarped Flat Fume Tarped Broadcast, Untarped,

12" Broadcast, Untarped,

18"

Estimated Reported Estimated Reported Estimated Reported Estimated Reported
05/28/2008, ST

- 14:00* 7.18 5.66 8.4 9.96 10.1 14.5 24.0 37.07
05/28/2008, 14:00

- 19:30 12.8 14.7 13.6 15.6 11.0 9.8 7.0 8.0
05/28/2008, 19:30

- 1:30 11.5 12.1 15.4 16.0 17.1 17.9 32.4 33.9
05/29/2008, 1:30

- 7:30 21.5 7.46 9.8 14.1 25.2 4.8 55.8 64.1
05/29/2008, 7:30

- 13:30 55.3 57.6 36.6 38.1 23.6 24.6 26.7 27.8
05/29/2008, 13:30

- 19:30 72.7 75.1 34.9 35.9 30.0 30.9 34.6 35.6
05/29/2008, 19:30

- 1:30 22.8 28.6 19.0 20.0 57.0 60.5 59.9 74.8
05/30/2008, 1:30

- 7:30 14.2 14.9 10.6 11.1 34.2 35.7 49.4 51.6
05/30/2008, 7:30

- 19:30 56.6 61.6 19.9 21.7 16.2 17.7 23.7 25.9
05/30/2008, 19:30

- 7:30 22.3 25.0 16.7 18.7 35.5 39.9 42.9 56.2
05/31/2008, 7:30

- 19:30 34.9 38.8 12.3 13.7 10.0 11.2 14.1 15.7

* ST = start time. ST = 07:26 for Field 1, 09:30 for Field 2, 10:55 for Field 3, and 12:15 for Field 4.Page 54 of 62 Monitoring of Chloropicrin Emissions from Field and Greenhouse Drip Irrigation Applications, and Implied Worker Inhalation Exposure from Applications of Chloropicrin by Shank Injection, Drip Irrigation Systems and at Tree Replant Sites (MRID 46420201 )

– Site 16

Chloropicrin was applied via drip irrigation to a raised bed, tarped field, 8.7 acres (4.5 treated acres), in Salinas, CA at a rate of 155.7 pounds ai per acre in August, 2003

. Application began at 7:30 A M and was complete at 11:15 A M. A stan dard polyethylene tarp was placed over the application plot . Reentry tarp punching was conducted 10 days after application. Samplers were placed at a height 1.5 meters above the ground. Air samplers were also placed on a mast at the center of the field, taking air measurements at 15, 33, 55, 90, and 150 centimeter heights for aerodynamic flux estimates. Wind speed and temperature measurements were also made at the center of the field

. Flux estimates

for the first 48 hours are provided in Table 15

.

Tabl e 15 . Flux Rates Obtained from Salinas, CA Study

Period Day/Hour Flux Rate (ug/m 2

- s)

1 Day 0, Hours 0

– 4 27.0

2 Day 0, Hours 4

– 8 70.1

3 Day 0 , Hours 8

– 12 23.3

4 Day 0 , Hours 12

- 16 5.7

5 Day 0 , Hours 1 6

– 20 4.8

6 Day 0, Hours 20

– 24 2.6

7 Day 1, Hours 0

– 4 7.3

8 Day 1, Hours 4

– 8 11.7

9 Day 1 , Hours 8

– 12 5.7

10 Day 1 , Hours 12

- 16 2.2

11 Day 1 , Hours 1 6

– 20 0.9

12 Day 1, Hours 20

– 24 0.9

Direct Flux Determination of Chloropicrin Emissions from Shank, Bedded,

Non

- Tarped Applications (MRID 48033801 )

Pic Plus (85.5% chloropicrin) was applied at a target rate of 175 lb /ac to a 3

- acre field in Elkton, FL in December 3, 2009. Air monitoring was accomplished using sorbent tubes and SKC® personal air sampling pumps. Flux mo nitoring was conducted with a single mast cantrally located in the plot. The mast was constructed to sample the air at sic heights: 15, 33, 55, 90, 150 and 180 cm. Flux estimates for the first 27 hours are provided

in Table 16

.Page 55 of 62 Table 16 . Flux Rates Obtain ed from Elkton, FL Study

Period Duration (hr) Time (middle of period) Flux Rate (ug/m 2

- s)

1 2.6 12/3/09 17:43 5.556

2 6 12/3/09 22:00 0.593

3 6 12/4/09 4:00 0.423

4 6 12/4/09 10:00 0.706

5 6 12/4/09 16:00 0.198

Monitoring 1,3

- Dichloropropene, Chloropicrin and Methyl Isothiocyanate Emissions from Shank Applications at Three Sites Near Duette, Florida (MRID 47813901 )

A comparative emissions data were generated from three different shank application

scenarios in a bed

- plastic mulch vegetable production system. All three tests were conducted in close proximity and on the same date with concurrent air and soil monitoring to ensure meteorological and soil conditions. The flux rates were computed using the integrated horizontal f lux method (IHF). Each test field plot was approximately one acre in size. The chloropicrin application was approximately 170 lb/acre. Profile samples were collected on sampling masts places at the approximate center of each plot of the test fields short ly after passage of the application rig. Air sample tubes were placed along the vertical profiles on each filed at 1, 3, 6, and 10 ft above each field during each period of the study. Flux estimates for the three fields are provided in Table

17

.

Table 1 7 . Flux Rates Obtained from Duette, FL Study

Sample Interval

Times Field 1 Field 2 Field 3

Metalized Film Virtually Impermeable

Film Metalized Film

(ug/m2

- s) (ug/m2

- s) (ug/m2

- s)

Estimated Reported Estimated Reported Estimated Reported

1/14/2009 9:30

- 15:30 17.05 18.67 1.77 2.24929 9.55 4.53704

1/14/2009 15:30

- 21:30 0.89219 0.00253 1.2612394 0.00259 0.003 0.00301

1/14/2009 21:30

- 3:30 6.57361 0.00261 5.3571934 0.00242 0.80874001 0.00285

1/15/2009 3:30

- 9:30 6.42487 0.00254 6.4067525 0.00275 1.20635673 0.00271

1/15/2009 9:30

- 15:30 16.586 0.0028 13.521113 0.00244 2.66537817 0.00296

1/15/2009 15:30

- 21:30 7.57669 0.00274 6.4205641 0.00284 1.33503861 0.0029

1/15/2009 21:30 1.80171 0.00276 1.374688 0.00222 1.81810091 0.00301Page 56 of 62 - 3:30

1/16/2009 3:30

- 13:30 2.60878 0.00274 16.14767 0.00262 3.22137123 0.00286

1/16/2009 13:30

- 1:30 7.20999 0.00261 0.9469805 0.00298 1.00569172 0.00285

1/17/2009 1:30

- 13:30 0.34477 0.26673 1.8243464 0.00299 0.27904869 0.00265

1/17/2009 13:30

- 1:30 0.14543 0.2659 0.1649281 0.00302 0.15136294 0.00243

1/18/2009 1:30

- 13:30 0.32508 0.22141 0.111022 0.0737 0.09852181 0.00256

1/18/2009 13:30

- 1:30 0.53899 0.38129 0.2740392 0.00297 0.30782014 0.00259

1/19/2009 1:30

- 13:30 0.39167 0.31492 1.3308907 0.00279 0.23839527 0.00277

1/19/2009 13:30

- 1:30 0.82339 0.60557 0.8049912 0.56659 0.43581863 0.00283

1/20/2009 1:30

- 13:30 1.10735 0.91726 1.2934923 0.96547 3.12117462 0.00269

1/20/2009 13:30

- 1:30 0.37205 0.46641 0.3920304 0.53091 0.47268152 0.00248

1/21/2009 1:30

- 13:30 0.29 0.00262 0.2880564 0.00269 0.27600537 0.00302

1/21/2009 13:30

- 1:30 0.16612 0.00251 0.1639747 0.00269 0.16809599 0.00262

1/22/2009 1:30

- 13:30 0.08596 0.0025 0.0872234 0.00279 0.08314276 0.0026

1/22/2009 13:30

- 1:30 0.0737 0.00247 0.0678296 0.00279 0.07184505 0.00275

1/23/2009 1:30

- 13:30 0.06781 0.00259 0.067549 0.0027

- 0.0006807 0.0027

Monitoring Methyl Bromide and Chloropicrin Field Emissions from Shank Applications at Shallow and Deep Injection Depths (MRID 48006001 )

The targeted application rates of 180 lb/ac were made to five 1

- acre field located near Wasco, CA on June 2, 2009. Air sampling was conducted starting with the beginning of each application and continued through June 15, 2009. The five test scenarios are as follows: (1) a shallow, broadcast, tarped application with 12” injection depth and polyethylene tarp sealing, (2) a shallow, broadcast, tarped application with 12” injection depth and EVOH resin barrier tarp sealing, (3) a shallow, broadcast, tarped application with 12” injection depth and polyethylene tarp + potassium thiosulfate sealing, (4) a deep, strip, tarped app lication with 18” injection depth and EVOH resin barrier tarp sealing, and (5) a deep, broadcast, tarped application with 18” injection depth and EVOH resin barrier tarp sealing. Flux estimates for the five fields are provided in Table 18

.Page 57 of 62 Table 18 . Flu x Rates Obtained from Wasco, CA Study Estimated flux (μg/m 2

- sec)

Duration Field1 Field2 Field3 Field4 Field5

06/02/2009 09:00

- 13:00 17.41 25.82 30.97 5.19 1.78

06/02/2009 13:00

- 19:00 31.03 6.97 7.2 5.19 1.78

06/02/2009 19:00

- 01:00 15.54 2.08 1.86 1.69 2.1

06/03/2009 01:00

- 07:00 17.48 0.89 0.91 0.86 0.91

06/03/2009 07:00

- 13:00 11.39 1.19 1.22 4.62 4.04

06/03/2009 13:00

- 19:00 23.97 5.32 5.95 6.33 5.47

06/03/2009 19:00

- 01:00 6.46 8.53 6 3.87 6.31

06/04/2009 01:00

- 07:00 1.3 1.97 1.76 2.52 5.9

06/04/2009 07:00

- 19:00 4.22 1.26 1.18 4.28 1.15

06/05/2009 19:00

- 07:00 1.14 1.74 1.61 1.7 1.58

06/05/2009 07:00

- 19:00 0.94 0.25 1.28 1.39 1.24

06/06/2009 19:00

- 07:00 0.86 1.36 0.89 0.95 0.88

06/06/2009 07:00

- 19:00 1.5 1.64 1.46 1.54 1.4

06/07/2009 19:00

- 07:00 0.41 0.77 0.72 0.6 0.58

06/07/2009 07:00

- 19:00 0.68 1.43 1.29 1.3 1.24

06/08/2009 19:00

- 07:00 0.59 1.66 0.84 0.63 0.62

06/08/2009 07:00

- 13:00 0.05 3.86 0.85 0.8 2.25

06/08/2009 13:00

- 19:00 1.45 2.82 1.4 4.76 5.93

06/08/2009 19:00

- 01:00 0.1 1.31 1.2 4.6 3.47

06/09/2009 01:00

- 07:00 1.52 1.53 1.56 1.5 2.65

06/09/2009 07:00

- 19:00 1.65 1.57 1.6 2.03 2.46

06/10/2009 19:00

- 07:00 1.2 1.52 1.23 0.65 1.62

06/10/2009 07:00

- 19:00 1.79 3.08 1.79 1.81 0.57

06/11/2009 19:00

- 07:00 1.85 0.93 1.19 0.93 1.26

06/11/2009 07:00

- 19:00 1.3 0.88 0.99 1.54 1.45

06/12/2009 19:00

- 07:00 0.74 0.83 0.79 0.73 1.01

06/12/2009 07:00

- 19:00 1.49 1.64 1.5 1.44 1.38

06/13/2009 19:00

- 07:00 1.3 1.36 1.35 0.93 1.37

06/13/2009 07:00

- 19:00 1.58 1.69 1.61 1.93 1.49

06/14/2009 19:00

- 07:00 0.96 1.05 0.98 1.09 0.95

06/14/2009 07:00

- 19:00 1.54 1.61 1.47 1.74 1.42

06/15/2009 19:00

- 07:00 0.72 0.79 0.64 0.73 0.66Page 58 of 62 Monitoring of Methyl Bromide and Chloropicrin Field Emissions from Shank (Bedded and Broadcast) and a Methyl Bromide Hot

- Gas Application under Totally Impermeable Film (MRID 48107601 )

The objective was to generate comparative emissions dada from three app lication methods for methyl bromide and chloropicrin at practical application rates for each method. Among the three, only one test generates useful chloropicrin emission data.

The test is for in

- bed shank application under TIF (totally impermeable tar p). This application was conducted January 15 on a vegetable farm just north of Ft. Pierce, FL. The applied are was 0.59 acres. The targeted rate is 235 lb/ac chloropicrin. Flux estimates are provided in Table 19

.

Table 19 . Flux Rates Obtained from Fort Pierce, FL Study

Period

No. Sample Interval Times Start Time Duration Reported Flux
(ug/m2

- s)

1 1/15/2010 9:45

- 13:00 1/15/10 9:45 3:15 14.1

2 1/15/2010 13:00

- 19:00 1/15/10 13:00 6:00 0.11

3 1/15/2010 19:00

- 01:00 1/15/10 19:00 6:00 0.05

4 1/16/2010 01:00

- 07:00 1/16/10 1:00 6:00 0.66

5 1/16/2010 07:00

- 13:00 1/16/10 7:00 6:00 0.13

6 1/16/2010 13:00

- 19:00 1/16/10 13:00 6:00 0.17

7 1/16/2010 19:00

- 01:00 1/16/10 19:00 6:00 0.15

8 1/17/2010 01:00

- 07:00 1/17/10 1:00 6:00 4.72

9 1/17/2010 07:00

- 19:00 1/17/10 7:00 12:00 0.39

10 1/17/2010 19:00

- 07:00 1/17/10 19:00 12:00 0.07

11 1/18/2010 07:00

- 19:00 1/18/10 7:00 12:00 0.05

12 1/18/2010 19:00

- 07:00 1/18/10 19:00 12:00 0.01

13 1/19/2010 07:00

- 19:00 1/19/10 7:00 12:00 0.17

14 1/19/2010 19:00

- 07:00 1/19/10 19:00 12:00 0.02

15 1/20/2010 07:00

- 19:00 1/20/10 7:00 12:00 0.29

16 1/20/2010 19:00

- 07:00 1/20/10 19:00 12:00 0.11

17 1/21/2010 07:00

- 19:00 1/21/10 7:00 12:00 1.34

18 1/21/2010 19:00

- 07:00 1/21/10 19:00 12:00 0.05

19 1/22/2010 07:00

- 19:00 1/22/10 7:00 12:00 0.05

20 1/22/2010 19:00

- 07:00 1/22/10 19:00 12:00 0.02

21 1/23/2010 07:00

- 19:00 1/23/10 7:00 12:00 0.29

22 1/23/2010 19:00

- 07:00 1/23/10 19:00 12:00 0.04

23 1/24/2010 07:00

- 20:00 1/24/10 7:00 13:00 0.12

24 1/24/2010 20:00

- 07:45 1/24/10 20:00 11:45 0.08Page 59 of 62 Monitoring 1,3

- Dicholoropropene and Chloropicrin Emissions from Solid

Tarp Shank Injections at Two Sites Near Fort Pierce, Florida (MRID

48085701 )

The objective was to generate comparative emissions dada from two different shank application scenarios (standard shank injection versus low distributed shank injection) in a Florida vegetable production system. Air concentrations were monitored over a 10

- day

period using solid sorbent air sampling tubes. The flux rates were computed using the integrated horizontal flux method (IHF) based on measured air concentrations along the vertical profile (from 0.3 to 2.4 m). For field 1, prior to application, the soil surface was sealed with a single drum smooth roller. The fumigant was applied with a low disturbance application rig at 8” depth. The soil was immediately covered with smooth, 1.0 mil, high density polyethylene (HDPE) plastic. For field 2, prior to application, soil tillage was performed using a field cultivator with rolling basket attachments. The fumigant was applied using swept back shanks at 8” depth. The soil was also immediately covered with HDPE plastic. Flux estimates are provided in Table 20

.

Table 20 . Flux Rates Obtained from Fort Pierce, FL Study

Period

No. Field 1 Field 2

Sample Interval Times Reported

Flux (ug/m2

- s) Sample Interval Times Reported

Flux (ug/m2

- s)

1 11/17/2009 8:30

- 18:30 19.89 11/17/2009 8:00

- 12:00 4.23

2 11/17/2009 18:30

- 18:30 19.89 11/17/2009 12:00

- 19:00 32.48

3 11/17/2009 18:30

- 11/18/2009 0.30 24.21 11/17/2009 19:00

- 11/18/2009 1:00 27.35

4 11/18/2009 0:30

- 6:30 14.47 11/18/2009 1:00

- 7:00 28.42

5 11/18/2009 6:30

- 12:30 42.07 11/18/2009 7:00

- 13:00 25.64

6 11/18/2009 12:30

- 18:30 46.83 11/18/2009 1:00

- 19:00 46.49

7 11/18/2009 18:30

- 11/19/2009 0:30 15.17 11/18/2009 19:00

- 11/19/2009 1:00 21.95

8 11/19/2009 0:30

- 6:30 11.34 11/19/2009 1:00

- 7:00 16.40

9 11/19/2009 6:30

- 18:30 32.51 11/19/2009 7:00

- 19:00 39.03

10 11/19/2009 18:30

- 11/20/2009 6:30 8.24 11/19/2009 19:00

- 11/20/2009 7:00 14.52

11 11/20/2009 6:30

- 18:30 17.54 11/20/2009 7:00

- 19:00 17.86

12 11/20/2009 18:30

- 11/21/2009 6:30 4.91 11/20/2009 19:00

- 11/21/2009 7:00 7.66

13 11/21/2009 6:30

- 18:30 14.07 11/21/2009 7:00

- 19:00 15.51

14 11/21/2009 18:30

- 11/22/2009 6:30 7.79 11/21/2009 19:00

- 11/22/2009 7:00 7.80

15 11/22/2009 6:30

- 18:30 10.88 11/22/2009 7:00

- 19:00 9.44

16 11/22/2009 18:30

- 11/23/2009 6:30 8.64 11/22/2009 19:00

- 11/23/2009 7:00 7.21Page 60 of 62 17 11/23/2009 6:30

- 18:30 11.15 11/23/2009 7:00

- 19:00 12.29

18 11/23/2009 18:30

- 11/24/2009 6:30 4.78 11/23/2009 19:00

- 11/24/2009 7:00 4.33

19 11/24/2009 6:30

- 18:30 7.48 11/24/2009 7:00

- 19:00 6.90

20 11/24/2009 18:30

- 11/25/2009 6:30 4.02 11/24/2009 19:00

- 11/25/2009 7:00 3.65

21 11/25/2009 6:30

- 18:30 3.85 11/25/2009 7:00

- 19:00 4.82

22 11/25/2009 18:30

- 11/26/2009 6:30 3.13 11/25/2009 19:00

- 11/26/2009 7:00 2.73

23 11/26/2009 6:30

- 18:30 3.02 11/26/2009 7:00

- 19:00 6.57

24 11/26/2009 18:30

- 11/27/2009 6:30 0.99 11/26/2009 19:00

- 11/27/2009 7:00 1.19

Chloropicrin Flux Rates for Drip Fumigation with PE and TIF Tarps, Water Seal and KTS at Salinas, California in September 2007 (MRID 48087401 )

The objective was to generate comparative emissions dada from four drip applications of chloropicrin, with all f ield located in close proximity to each other, and with air monitoring conducted concurrently to ensure that meteorological and soil conditions were similar at all four sites. The design differences among each field are the sealing methods.

Field #1 was tarped with standard LDPE, and no water seal and without potassium thiosulfate addition. Field #2 was tarped with TIF, and no water seal and without potassium thiosulfate addition. Field #3 was tarped with standard LDPE, and with water seal and with pota ssium thiosulfate addition. Field #4 was tarped with standard LDPE, and with water seal and without potassium thiosulfate addition. The flux estimates are presented in Table 21 to Table 24.

Table 21 . Flux Rates Obtained Field #1 from Salinas, CA Study

Per iod Sample Interval Times Est. Flux Reported Flux

No. (ug/m2

- s) (ug/m2

- s)

1 9/27/2007 08:00

- 12:45 72.48 70.62

2 9/27/2007 12:45

- 18:30 108.74586 77.732

3 9/27/2007 18:30

- 00:45 17.69839 17.73

4 9/28/2007 00:45

- 06:30 6.8765511 10.09

5 9/28/2007 06:30

- 12:30 17.475552 14.61

6 9/28/2007 12:30

- 18:30 10.896526 8.51

7 9/28/2007 18:30

- 00:30 4.5526754 4.18

8 9/29/2007 00:30

- 06:30 2.0175433 1.88

9 9/29/2007 06:30

- 18:30 1.2132923 1.03

10 9/29/2007 18:30

- 06:30 1.9034823 1.71

11 9/30/2007 06:30

- 18:30 0.9475694 0.78

12 9/30/2007 18:30

- 06:30 0.669106 0.39

13 10/1/2007 06:30

- 18:30 0.4130348 0.33Page 61 of 62 14 10/1/2007 18:30

- 06:30 0.2196138 0.5

Table 22 . Flux Rates Obtained Field #2 from Salinas, CA Study

Period

No. Sample Interval Times Est. Flux Reported Flux
(ug/m2

- s) (ug/m2

- s)

1 9/27/2007 08:00

- 13:00 12.18 3.96

2 9/27/2007 13:00

- 19:00 9.9188583 5.38

3 9/27/2007 19:00

- 01:00 5.0246402 2.48

4 9/28/2007 01:00

- 06:45 2.0274643 1.39

5 9/28/2007 06:45

- 12:45 5.4529102 2.15

6 9/28/2007 12:45

- 18:45 3.7133395 0.5

7 9/28/2007 18:45

- 01:00 0.1244568 0.5

8 9/29/2007 01:00

- 07:00 0.0280541 0.1

9 9/29/2007 07:00

- 19:00 1.0429712 0.5

10 9/29/2007 19:00

- 07:00 0.3752138 0.1

11 9/30/2007 07:00

- 19:00 0.0710577 0.5

12 9/30/2007 19:00

- 07:00 0.1493052 0.1

13 10/1/2007 07:00

- 19:00 0.3027861 0.1

14 10/1/2007 19:00

- 07:00 0.0083464 0.1

Table 23 . Flux Rates Obtained Field #3 from Salinas, CA Study

Period

No. Sample Interval Times Est. Flux Reported Flux
(ug/m2

- s) (ug/m2

- s)

1 9/27/2007 08:00

- 13:15 15.66 19.15

2 9/27/2007 13:15

- 19:15 74.324839 10.82

3 9/27/2007 19:15

- 01:15 39.377305 7.1

4 9/28/2007 01:15

- 07:15 21.792712 8.82

5 9/28/2007 07:15

- 13:00 35.161154 5.68

6 9/28/2007 13:00

- 19:00 46.471985 4.9

7 9/28/2007 19:00

- 01:15 20.070334 3.69

8 9/29/2007 01:15

- 07:15 13.31243 3.04

9 9/29/2007 07:15

- 19:15 12.751401 1.56

10 9/29/2007 19:15

- 07:15 11.860213 1.79

11 9/30/2007 07:15

- 19:15 3.3435154 2.03

12 9/30/2007 19:15

- 07:15 1.1267063 0.85

13 10/1/2007 07:15

- 19:15 3.3279015 0.5

14 10/1/2007 19:15

- 07:00 0.8679198 0.49Page 62 of 62 Table 24 . Flux Rates Obtained Field #4 from Salinas, CA Study

Period

No. Sample Interval Times Est. Flux Reported Flux
(ug/m2

- s) (ug/m2

- s)

1 9/27/2007 08:00

- 13:30 65.69 50.44

2 9/27/2007 13:30

- 19:30 103.7689 29.53

3 9/27/2007 19:30

- 01:30 48.388789 13.76

4 9/28/2007 01:30

- 07:30 22.938605 9.78

5 9/28/2007 07:30

- 13:15 43.511546 7.04

6 9/28/2007 13:15

- 19:30 19.707023 5.19

7 9/28/2007 19:30

- 01:30 16.994678 3.32

8 9/29/2007 01:30

- 07:30 12.379164 2.25

9 9/29/2007 07:30

- 19:30 8.5184615 1.46

10 9/29/2007 19:30

- 07:30 8.4661379 0.92

11 9/30/2007 07:300

- 19:30 2.7015752 0.5

12 9/30/2007 19:30

- 07:30 0.5635278 0.23

13 10/1/2007 07:30

- 19:45 0.6853856 0.5

14 10/1/2007 19:45

- 07:30 0.6893363 0.5