UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

MAR 2~ 2013 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: BEAD Chemical Profile for Registration Review: 1,3-Dichloropropene (1,3-D) 

(029001) 

FROM: 

THRU: 

TO: 

Carl Chen, Plant Pathologist 

Biological Analysis Branch 

Cynthia 

Science Information 

Doucoure, Environmental 

and Analysis Branch 

Protection Specialist t-~ 

Derek Berwald, Economist V r;)_ lAJ\ l~ Economic Analysis Branch \j. j ,. '-X 

Biological and Economic Ana sis Division (750 

Amet Jones, Chief 

Biological Analysis Br 

Diann Sims, Chief A-L.--~.~---~ Science Information and Analysis Branch 

Economic 

Timothy Kiely, 

Analysis 

Chief 

Branch 

CrJr 

~ ) 

~ 

Biological and Economic Analysis Divisio (7503P) 

Andrea Mojica, Chemical Review Manager 

Risk Management and Implementation Branch 4 

Pesticide Reevaluation Division (7508P) 

Product Review Panel Date: February 13, 2013 

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INTRODUCTION 

The purpose of this document is to convey usage information and a broad overview of the pest 

management role of 1,3-Dichloropropene (1,3-D, also known as Telone) that is beginning to 

undergo registration review. The anticipated audience consists of the team of EPA staff 

currently evaluating the registration status of 1,3-D, and eventually the general public. This 

document builds upon the data already provided in the "Usage and Label Use Data Packages" 

that are also provided to the Registration Review team by BEAD. The document is based on 

information and data available to BEAD as of January 2013. 

1,3-D is a broad spectrum fumigant with nematicidal, fungicidal, herbicidal, and insecticidal 

properties that was initially registered in the U.S. in 1954 and reregistered in 1998. It has· been 

widely used to control soil-borne pests in a variety of crops and has made the top of the list in 

total area treated by fumigants in 2011, approximately 40% more than the second highest 

(Proprietary Data). However, there could be some limiting factors such as restrictions for 1,3-D 

use on karst soils and township caps for 1,3-D use in California. Nematodes are the main pest 

targeted by its use. As a nematicide, the chemical penetrates into nematodes via mouth and 

cuticle. 

1,3-D can be mixed with chloropicrin to enhance plant pathogen and weed control. InLine®, 

Telone® C-17, Telone® C-35, and Pic-Clor 60 EC are commonly used combination products with 

1,3-D and chloropicrin, and the total amount of 1,3-D in these four products accounted for 

approximately a quarter of all 1 ,3-D used in 2011 (Proprietary Data). Any changes in use 

patterns due to risk mitigation for one of these fumigants will affect use patterns for the other; 

currently there are additional mitigation measures on 1 ,3-D product labels that also contain 

chloropicrin. 

HISTORY OF BEAD ASSESSMENTS FOR 1,3-D 

BEAD has done little significant work on the benefits of 1 ,3-D alone. In 1998 EPA issued aReregistration Eligibility Decision (RED) for 1,3-D that contained only a brief mention that 1,3-D 

has value for nematode control. That RED discussion also predicted increased benefits for 1,3-D 

as methyl bromide was phased out. Although past BEAD work has not estimated the value of 

1,3-D to growers, it is useful to note that growers choose 1,3-D to provide protection to crops 

with high value per acre, such as potatoes, strawberries, vegetables and orchards. 

BEAD has done substantial work on the benefits of other fumigants, and 1,3-D was sometimes 

included as either an alternative fumigant, or because it is applied in combination with fumigants 

such as chloropicrin. In general, BEAD work has found substantial benefits to fumigants in 

general in a variety of crops. When evaluating methyldithiocarbamate salts such as metam 

sodium and metam potassium, 1 ,3-D was frequently mentioned as a part of an alternative 

fumigant program to those featuring metam sodium or metam potassium. In general, these 

alternative programs featuring 1,3-D (sometimes in combination with chloropicrin) were less 

cost-effective alternatives to those featuring metam sodium or metam potassium. This should 

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not be interpreted as implying a low value for 1,3-D, because that these were evaluations of pest 

management systems where growers had not chosen to use 1,3-D. 

1,3-D is often applied in combination with chloropicrin in_ some crops, and that combination has 

substantial value to growers. It isn't possible to say, based on past BEAD evaluations, what 

benefits are derived from the 1,3-D portion of that combination. 

1,3-D, in combination with other fumigants is also frequently included in the list of alternatives 

to methyl bromide as use of that chemical is phased out. As the phaseout completes, the relative 

importance of 1,3-D as part of an alternative program to methyl bromide use can reasonably be 

expected to increase. Grower groups in California point out that township caps on the use of 1,3-

D may restrict its adoption as an alternative to methyl bromide. Use in Florida also faces 

restrictions in use near karst formations. 

COMMON FORMULATIONS AND APPLICATION METHODS 

1,3-D is commonly formulated as pressurized gas, liquid ready to use, and emulsifiable and 

flowable concentrate applied as a soil fumigant via soil injection, drip irrigation, tarped and 

untarped broadcast applications using shank, plowsole or chisel equipment, as well as bedded 

applications using chisel equipment. 

USE SITES 

Agricultural Use Sites: 

1,3-D is registered for use on the soils of.agricultural crops including all vegetable crops (root 

crops such as beets, carrots, onions, potatoes, and radish; leafy vegetables such as lettuce; fruiting 

vegetables such as chili peppers; cole crops, and cucurbits, such as melons). 1,3-D is also registered 

for use on soils of legumes such as beans, peanuts, and soybeans; flavoring and spice crops such as 

hops and mint; field crops such as corn and tobacco; fiber crops such as cotton; fruit crops such as 

citrus and pineapple; and nut crops. 

Non-Agricultural Use Sites: 

1,3-D is registered for use on soils of nonagricultural crops including all nursery crops 

(ornamental, non-bearing fruit/nut trees and forestry crops), ornamental lawns and turf, golf course 

turf, ornamental and/or shade trees, ornamental herbaceous and nonflowering plants, and 

ornamental woody shrubs and vines. 

USAGE 

Agricultural Use Trend, 1998-2011 

Available data on.use of 1,3-D in the U.S., as found in private market surveys, show that the 

overall pounds a.i. applied increased between 1998 and 2011 as shown in Figure 1. The total 

area treated (acres) with 1,3-D increased steadily until2006, after which the acre treatments 

declined with slight increases in recent years as shown in Figure 2. Approximately 27,000,000 

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pounds of 1,3-D were applied on average annually to 310,000 acres at an overall average 

application rate of 87 lbs ail acre. As shown in Table 1, however, there is substantial variation in 

application rates in different crops. 

Figure 1: 1,3-D: Pounds A.l. Applied, 1998-2011 

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008. 2009 2010 2011 

Year 

Source: Proprietary Data, 1998-2011 

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Figure 2. 1,3-D: Total Area Treated, 1998-2011 

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 

Year 

Source: Proprietary Data, 1998-2011 

Agricultural Use 2007-2011 

During the 2007-2011 timeframe, approximately 32,000,000 pounds of 1,3-D were applied on 

average annually to 340,000 acres at an Qverall average application rate of 94 lbs ail acre. The top 

crops in terms of pounds a.i .. applied during this period were potatoes (45%), tobacco (14%), 

strawberries (6%), cotton (4%) and onions (4%) as shown in Figure 3 below. The top crops in 

terms of total area treated were the same; however the percentages of the area of potatoes, 

strawberries, and onions treated were lower than the percentage of pounds a.i. applied, implying 

higher than average a.i. rates of application. Conversely, the percentage of the total area of 

tobacco and cotton treated was higher than the percentage of pounds a.i. applied, implying a 

lower than average a.i. rate of application as shown in Table 1 below. 

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Figure 3. 1,3-D Use: Top Crops, 2007-2011 

Pounds AI Applied 

32 million lb annually 

Source: Proprietary Data, 2007-2011 

Total Area Treated 

340,000 acres annually 

3% 

Other crops include almonds, apples, asparagus, beans, broccoli, cabbage, caneberries, cantaloupes, 

carrots, cauliflower, cherries, cucumbers, garlic, grapes, lemons, oranges, peaches, peanuts, peppers, 

pumpkins, squash, sugar beets, sweet com, tomatoes, walnuts, and watermelons. 

For some· crops that do not top the list for pounds applied, a significant portion of the acreage is 

treated with 1,3-D. Based on the BEAD SLUA for 2003-2010, crops that have an average 

percent crop treated greater than 10% were cantaloupe, carrot, cucumber, peppers, potato, 

strawberry, and tobacco. Most of these crops have too small an acreage to show up as one of the 

primary uses for 1,3-D, but the use is still important for those growers. 

Table 1 1,3-D Use on Top Crops: Average AI. Rate, 2007-2011 

Av_g. AI Rate Obs a.i./acre) 

Potatoes 137 

Strawberries 159 

Onions 155 

Tobacco 75 

Cotton 28 

Source: Proprietary Data, 2007-2011 

The top states in terms of pounds a.i. applied during this period were Washington (20% ), Idaho 

(19%), California (15%), and North Carolina (13%). However, the percentage of the total area 

treated with 1,3-D in California, Idaho, and Washington was lower than the pounds a.i. applied, 

implying higher than average a.i. rates of application while in North Carolina, the percentage of 

the total area treated was slightly higher than the pounds a.i. applied, implying slightly lower 

than average a.i. rates of application. These differences are explained by the application rates 

shown in Table 1, because the primary use in North Carolina is on tobacco, which has lower 

rates than potatoes and onions grown in the Northwest or strawberries in California. 

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Figure 4. 1,3-D Use: Top States, 2007-2011 

Pounds AI Applied 

32 million pounds annually 

Source: Propriet¥Y Data, 2007-2011 

Total Area Treated 

340,000 acres annually 

CAliFORNIA 

IDAHO 

1196 

NORTH 

CAROLINA 

1596 

Other states include AL, AR. AK, CO, FL, GA, IN, KY, MI, MN, MO, NE, NM, NY, OR, PA, SC, TN, 

TX, VA, and WI. 

Agricultural Usage by Crop Reporting District 

Another mea5ure of usage is the use intensity. In this analysis, the use intensity is expressed as 

the pounds a.i. applied per 1,000 acres of land in farms. This differs from the application rate, 

which is expressed as the pounds a.i. applied per treated area. Figure 5 spatially represents 1,3-

D's use intensity in the U.S. · The average application rate of94 pounds per acre would be 

equivalent to 94,000 pounds per 1,000 treated acres. In contrast, the maximum intensity 

represented in Figure 5 is about 1,200 pounds per 1,000 acres of farmland. Tpese areas of high 

use intensity are seen in 'Idaho, which reflects high use rates on large acreage of potato, and 

Eastern North Carolina, where use on tobacco is common. 

Page 7 oflO 
Figure 5. 1,3-D Usage by Crop Reporting District (2007- 2011) 

Average Pounds Per 

1,000 Acres of Farmland 

- <88 

88-230 

c:::J 231-475 

0 476-836 

837- 1,203 

This is a map of agricultural pesticide usage at the Crop Reporting District (CRD) level prepared by BEAD 

for use in the Environmental Fate and Effects Division documents. These maps are used to help visualize 

where the pesticide being considered is most likely to be used and can be helpful in scenario selection and 

placing the exposure assessment in context. CRDs are boundaries created by USDA NASS which are 

aggregates of counties. Pesticide usage is displayed as average pounds (for the years 2007-2011) per 1,000 

acres of farmland in a CRD to normalize for the variation in farmland between CRDs. Farmland acreage was 

obtained from USDA (2007). Farmland or "land in farms" is defined as follows: 

The acreage designated as "land in farms" consists primarily of agricultural land 

used for crops, pasture, or grazing. It also includes woodland and wasteland not 

actually under cultivation or used for pasture or grazing, provided it was part of 

the farm operator's total operation. Large acreages of woodland or wasteland 

held for nonagricultUral purposes were deleted from individual reports durinr 

the edit process. Land in farms includes CRP, WRP, FWP, and CREP acres. 

Land in farms . is an operating unit concept and includes land owned and 

operated as well as land rented from others. Land used rent free was reported as 

land rented from others. All grazing land, except land used under government 

permits on a per-head basis, was included as "land in farms" provided it was 

part of a farm or ranch. Land under the exclusive use of a grazing association 

1 CRP: Conservation Reserve Program; WRP: Wetland Reserve Program; FWP: Farmable Wetlands Program; 

CREP: Conservation Reserve Enhancement Program 

Page 8 oflO 
was reported by the grazing association and included as land in farms. All land 

in American Indian reservations used for growing crops, grazing livestock, or 

the potential of grazing livestock was included as land in farms. Land in 

reservations not reported by reservation, individual American Indians or nonNative Americans was reported in the name of the cooperative group that used 

the land. In many instances, an entire American Indian reservation was reported 

as one farm (USDA, 2007). 

Usage is based on private market surveys of pesticide use in agriculture (Proprietary Data, 2007-2011). The 

survey data are limited to the states that represent the top 80-90% of acreage for the individual crops, 

therefore, use may be occurring in regions outside the scope of the survey. CRDs showing no usage of 

pesticides may be due to either the lack of pesticide use in the region or non-participation in the agricultural 

surveys. ·In addition, across the years, there may be variations in the specific crops included in the CRD 

survey. 1bis may result in a lower annual average for the CRD. 

1bis map displays ratio data (Le., average pounds per 1,000 acres of farmland) summarized at a very highlevel. Readers are strongly cautioned against trying to over interpret the map without examination of the 

underlying data. The underlying data may explain some of the many reasons that a Crop Reporting District 

may have a high value for a particular active ingredient such as significant acreage (compared with the CRD 

as a whole) of a crop or crops with a high application rate and frequency of application. 

The reader should pay particular attention to the figure legends and realize that a map prepared for a 

particular chemical is not directly comparable to a map prepared for a different chemical. Scale and units of 

measurement do matter and may be different between maps. 

Sources: 

Proprietary Data. 2007-2011. 

USDA, 2007. Census of Agriculture. Online: http://www.agcensus.usda.gov/Publications/2007/index.asp. 

Non-Agricultural Use 

BEAD reviewed available sources for non-agricultural usage information and found that USDA 

NASS surveys use of 1,3-D in Nursery and Floriculture. In 2009, the survey reported that 

319,000 pounds of 1,3-D was applied to nursery and floriculture at an average rate of236.7 

pounds per acre. California has a Special Local Need label for 1,3-D use in nursery for 

nematode control. 

BIOLOGICAL ASPECTS· RELEVANT TO 1,3-D 

1,3-D is a non-selective fumigant. The risk for pests to develop resistance to 1,3-D is low. It is 

used as a preplant soil fumigant to kill soil dwelling pests. The non-agricultural use of 1,3-D 

(nursery and floriculture) also involves preplant soil fumigation for killing soil-borne pests. 

However, CordonTM, a single active ingredient product of 1,3-D, may be applied as a.postplant 

and postharvest soil treatment to suppress grape phylloxera and nematodes in established 

vineyards using drip irrigation systems. 

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One of reasons for the increase in 1,3-D use for soil fumigation is probably due to methyl 

bromide phaseout (http://www.epa.gov/ozone/mbrO. This is supported, for example, by the use 

of fumigants on cucumber. The total area treated by 1,3-D increased more than 40% from 2010 

to 2011, compared to a decrease of methyl bromide use down to zero, where the total acreage of 

all other fumigants was negligible on cucumber in 2011 (Proprietary Data). 1,3-D has similar 

qualities of methyl bromide such as the effectiveness on nematodes and is important as one of 

alternatives of methyl bromide. 

INFORMATION THAT MAY BE USEFUL FOR BEAD'S FUTURE WORK ON 1,3-D 

Additional information on typical1,3-D use in the non-agricultural sector and 1,3-D use as a 

postplant soil treatment would improve future BEAD assessments of the importance of 1,3-D 

and may be required as part of the registration review for this pesticide. Requested data should 

include, but not be limited to, application timing, application rate, application method, and 

application frequency. 

CONCLUSION 

1,3-D is applied to a wide variety of crops as a fumigant to control soil-borne plant pests. Many 

of these crops are high in value to the grower, and there are few alternative fumigants available. 

For these reasons, it is likely that 1,3-D has high benefits and that potential risk mitigation 

measures that restrict its use might be costly. · 

REFERENCES 

Proprietary Data, 1998-2011. 

USDA, 2006-2010. NASS Crop Reporting Districts. 

http://www.ers.usda.gov/briefing/arms/resourceregions/resourceregions.htm#nass. 

USDA, 2007. Census of Agriculture. 

http://www .agcensus. usda. gov /Publications/2007 /index.asp. 

USDA, 2009. NASS Agricultural Chemical Usage Reports, Nursery & Floriculture 

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