Syngenta Crop Protection, Inc. 

Legal Group 

2 Righter Parkway 

Wilmington. DE 19803 

Heather C. Wlnett 

Tel. (302) 476-21 12 

Fax (302) 476-201 2 

heather.winettesyngenta.com 

Via Federal Express 

August 30,2001 

Kathleen Franklin 

U.S. Environmental Protection Agency 

Ariel Rios Building -5 104 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 20460 

Re: Requested De-Listing of Paraquat Dichloride from SARA Title IZI, Section 302; 

Zeneca Ag Products Inc. v. US. EPA 

Dear Ms. Franklin: 

Endosed is the information you and your colleagues requested at our meeting in EPA's office 

in December 1999 to demonstrate that Paraquat dichloride, though classified as a restricted use 

pesticide, would not be a danger to the community if it were delisted from the SARA 302 Extremely 

Hazardous Substance List. We have presented this information in a "Q&A7' format to reflect the 

specific questions raised by EPA. Responses to Questions 5 and I1 will be provided in a 

supplement in the near future. By way of clarification, in January 2001, Zeneca Ag Products 

merged into S yngenta Crop Protection, Inc. (while the name of the original registrant of Paraquat in 

1978 was ICI Americas Inc.); for the purposes of this matter, these various names now all refer to 

the same company - Syngenta. 

After you have had a chance to review this material, S yngenta representatives would be glad to 

meet with you again or convene a conference call to determine next steps. Withespect to the 

matter currently before the District Court for the District of Columbia, as you know, the parties have 

asked the court to hold this matter in abeyance pending settlement discussions. 

Question 1: Why is Paraquat a Restricted Use pesticide? Is this classification relevant to EPCRA? 

Answer 1: EPA originally classified all Paraquat products as Restricted Use pesticides for FIFRA 

registration purposes based on acute toxicity and the potential for intentional or inadvertent 

exposure.' More recent acute data indicate lower toxicity for oral and dermal routes of exposure. 

EPA considers inhalation exposure not to be a concern, stating that "the spray droplets of Paraquat 

' 43 FR 5782, February 9, 1978. "Intentional and inadvertent exposure" typically involves poisoning by ingestion of 

humans and animals (e.g., suicide). 
Ms. Kathleen Franklin 

August 30,200 t 

Page 2 

from all current1 y registered products are not of respirable size and inhalation is not an exposure 

route of concern [emphasis added] ."2 

EPA further underscores this point in its occupational exposure assessment in its 1996 RED: 

Inhalation exposure and doses were not calculated since spray 

particles used in applying Paraquat are well beyond the respirable 

range and Paraquat has a very low vapor pressure.3 

Notwithstanding the Iack of acute toxicity concerns, EPA has maintained the Restricted 

Use classification for all Paraquat products "based on the severity of effects from Paraquat oral 

ingestion and inappropriate dermal exposure, limited effectiveness of therapeutic treatment after 

exposure and in order to continue to deter misuse ofthis product [emphasis added]." 

Clearly, then, this classification for FlFRA registration purposes is not relevant for 

EPCRA purposes. Paraquat is a Restricted Use pesticide due to oral and dermal exposure 

concern, whereas the concern for EPCRA is inhalation exposure, which is the most reIevant 

exposure pathway for EPCRA. By contrast, Paraquat was placed on the EPCRA Section 302 list 

based on a level of concern for inhalation exposure. The reasons for classifying Paraquat as 

Restricted Use pesticide, therefore, are unrelated to its classification the on the EPCRA list. 

Question 2: Are most Restricted Use pesticides on the EPCRA list of Extremely Hazardous 

Substances? 

Answer 2: No. See Attachment 2, which is a table listing aIl Restricted Use pesticides and shows 

which are on the SARA 302 list. This table is based on readily available information from the 

Office of Pesticide Programs. Of the 163 Restricted Use pesticides, only 54 (33 percent) are on the 

EPCRA list. Of the top ten selling pesticides for agricultural use (see EPA's Pesticides Idustry 

Sales and Usage: 1996 and 1997 Market Estimates), six are Restricted Use (atraine, rnetolachIor, 

metam sodium, methyl bromide, dchloropropene, and acetochlor). However, of these six, only 

methyl bromide is on the SARA 302 list. 

Question 3: Why did EPA require an inhalation study for Paraquat, and what particle sizes were 

used in the study? Confirm that it was a rat study. How dtd the laboratory create inhalable 

particles? 

Re-registration Eligibility Document for Paraquat, EPA 1996 ("RED) at p. 116 (copy enclosed, Attachment 1) 

1996 RED at p. 49. 4 1996 RED at p. 116. The Restricted Use classification significantly controIs access to the product by the general 

public and thereby helps controI its rnis-use as a poison by ingestion for humans and animals. 
Ms. Kathleen Franklin 

August 30,2001 

Page 3 

Answer 3: An acute inhalation study is part of the standard test battery for registering a pesticide 

(see 40 CFR 158.340). The acute inhalation study referenced in the RED included a 6-hour 

exposure, to Alderley Park SPF to respirable Paraquat pmcles with an aerodynamic diameter of 

2.5 microns or less5. The LCso for this study was 1 pg/L (or 0.001 g/m3). This study was used by 

EPA to set the Level of Concern for Paraquat in the EPCRA program. The laboratory created 

inhalation particles with an atomizer. 

Question 4: Is Paraquat ever in solid form in the production process? 

Answer 4: No. 

Question 5: Would the proposed change to Paraquat dichloride's status in EPCRA affect all solids 

in solution? Are many other pesticides solids in solution? 

Answer 5: Syngenta is still in the process of researching this issue and will. provide a response in 

its supplement, forthcoming in the near future. 

Question 6: Please provide a process flow diagram for the Paraquat dichloride production process. 

Answer 6: See Attachment 4. 

Question 7: WouIdn't the decision in Huls America, Inc. v. Carol Browner, 83 F .3d 445 (D.C. Cir. 1996) 

[upholding EPA's denial of a petition to &list isophorone diisocryanate ("'IPDI")] be dispositive of the 

arguments Syngenta advances for removing Paraquat dichloride fmm the EHS list? 

Answer 7: No. The Huh America case is easily distinguished from ~yngenta'sposition; in 

particular, S yngenta's legd challenge to EPA's denial of the petition to delis t Paraquat presents two 

new issues for judicial review not addressed by the Huls America court, Please see the legal 

memorandum prepared by McKenna & Cuneo, Attachment 5. 

Question 8: Does the SARA 3 11/312 tax in Florida apply directly to growers and farmers? 

Answer 8: Yes. Additional infomation can be obtained from the Florida Fruit and Vegetable 

Association. 

Gage, J.C., 'Toxicity of Paraquat and Diquat Aerosols Generated by a Size-Selective Cyclone: Effect of Particle Size 

Distribution," British Jod of Industrial Medicine, 25,304-3 14, 1968 
Ms. Kathleen Franklin 

August 30,2001 

Page 4 

Question 9: Is anyone else bringing Paraquat dichloride into the United States? 

Answer 9: To the best of S yngenta's knowledge, only one other company, Griffin LLC, currently 

imports Paraquat (as finished product under the brand name ~0s~) into the U.S. As far as Syngenta 

is aware, there is no powdered form anywhere in the world. Please see also Paraquat Shipment 

Analysis, Attachment 6. 

Question 10: When is Paraquat used by farmers? When is Paraquat on-site: after harvest? 

month-after-month? Is there a typical application rate for Paraquat? Is there a typical size of farm it 

is used on? 

Answer 10: Paraquat is used for both pre-emergence and post-emergence purposes (see labe1 

description, Attachment 7). However, the product is not typically stored on-site for months at a 

time; rather, it is used soon after purchase (typically, within days), and then more is purchased for 

subsequent use. Common usage rate is 1.7-2.0 ptslacre of formulated product. Syngenta' s 

Gramoxone g ax@ contains 3 Ibs of active ingredient per gallon; thus, in active ingredient terms, 

common use rate is .64 - .75 lbs per acres. Griffin's ~oa' contains 2.5 lbs per gallon, but the lbs 

A.1.lacre rate is the same. There is no "typical" size of farm or orchard about which Syngenta has 

information. Additional technical information, including the MSDS for Gramoxone g ax", is in 

Attachment 7. 

Question 11: Please provide a summary of the incident history of Paraquat. 

Answer 11: S yngenta has reviewed the six publicly available databases related to chemical 

incidents and is in the process of updating that review. A summary will be provided in Syngenta's 

supplementary response, forthcoming in the near future. 

We hope that your questions and concerns have been addressed. However, if you need any 

additional information or discussion, Syngenta would be pleased to respond further, 

CC wl attach: 

Nina Rivera, Esq., EPA 

Alan Carpian, DO3 

Peter Gray, Esq. 

Richard Reiss 

Sueanne Pfifferling 

Heather C. Winett 

Environmental Counsel 
Ms. Kathleen Franklin 

August 30,2001 

Page 5 

Attachments (see tabs): 

1. 1996RED 

2. Table 1: RU & Non-RU EHS 

3. [forthcoming with supplement] 

4. Process Flow Diagram 

5. Memorandum re Hulls America decision 

6. Shipment Analysis 

7. Technical Information (label, tech description; MSDS) 

8. Summary of Incident History [forthcoming with supplement]