UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

CERTIFIED MAIL 

Larry Hodges 

Bayer CropScience 

2 T.W. Alexander Drive 

PO Box 12014 

Research Triangle Park, NC 27709 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

February 2, 2011 

Re: EPA's response to waiver requests submitted by Bayer CropScience with the ethoprop 

registration review data call-in 90-day response (RR-0411 01-28718) 

Dear Dr. Hodges, 

The Environmental Protection Agency (EPA or the Agency) received Bayer 

CropScience's (Bayer's) 90-day response, dated December 1, 2010, to the ethoprop registration 

review data call-in (DCI), RR-041 101-28718. The 90-day response included requests for 

waivers for several data requirements (Guidelines 850. 1500, 875.2400, and 875.2500). The 

Agency has completed its review of the waiver requests and supporting documentation submitted 

by Bayer. Additional details are below: 

Guideline 850.1500, Freshwater fish life cycle toxicity 

The Environmental Fate and Effects Division (EFED) reviewed Bayer's request to waive 

the freshwater fish life cycle toxicity study. In the 90-day DCI response, Bayer noted that the 

Endocrine Disruptor Screening Program (EDSP) DCI also required a fish reproduction assay, 

and they felt it inappropriate to conduct two studies. 

As is further explained in the enclosed review (DP Barcode D384811), EFED considers 

the design, scope, and objectives of the freshwater fish full life cycle study (GDLN 850.1500) 

and the fish short-term reproduction assay (GLDN 890.1350, EDSP) to be substantially different, 

such that they are not interchangeable with respect to reproduction. Bayer's argument, as laid 

out in the DCI 90-day response, is not sufficient to support waiving GDLN 850.1500. 

However, because the Agency now has an acceptable estuarine I marine fish full life 

cycle study, EPA agrees to waive GDLN 850.1500, freshwater fish life cycle toxicity study. The 
October 30, 2008 Problem Formulation document (DP Barcode D353378), completed in support 

of the registration review of ethoprop, indicated the need for both a freshwater fish full life cycle 

and an estuarine I marine fish full life cycle study. An estuarine I marine fish full life cycle study 

(MRID 46315401) had been submitted previously but was classified as invalid. After a careful 

re-analysis, requested by Bayer, the Agency upgraded the estuarine I marine study to a 

supplemental status on April 30, 2009 (DP Barcodes D359201 and D306508). Since the 

estuarine I marine fish full life cycle study was re-classified and can now be used for risk 

assessment purposes, EFED believes that a second fish full life cycle study conducted in 

freshwater is not warranted. The estuarine I marine study allows EFED to sufficiently quantify 

chronic risk to fish. 

Guidelines 875.2400 and 875.2500, Post-application dermal and inhalation exposure studies 

The ethoprop registration review DCJ required post-application dermal and inhalation 

exposure data due to potential ethoprop exposure to workers during the transplanting of 

sugarcane. Specifically, the Agency is concerned about the potential exposure to workers 

involved in planting activities because of contact with either treated cane seed pieces or activities 

in previously treated fields. In the DCI 90-day response, Bayer requested waivers for these two 

studies stating: 

... Commercial sugarcane planting and the application of ethoprop are entirely 

mechanized processes with no post-application exposure to workers ... 

The sugarcane seed pieces are mechanically dropped from large tractor-drawn bins into 

open 4-inch deep furrows. The tractors are generally large enclosed cab vehicles because 

of the weight of the sugarcane planting bins ... 

Following placement of the sugarcane seed pieces in the furrow, ethoprop granules are 

mechanically applied over the top of the sugarcane seed pieces and soil is thrown over 

the seed pieces to close the furrow ... Mix the soil with a disc hiller or other suitable 

equipment as the cane is covered .. . 

The Health Effects Division (HED) has completed its review of Bayer's waiver request 

for GDLNs 875.2400 and 875.2500, and at this time, Bayer's waiver request is denied. The 

Agency continues to require the submission of post-application dermal and inhalation exposure 

data. RED's enclosed review (DP Barcode D384788) found conflicting information regarding 

sugarcane planting practices from various reputable sources. Although agricultural websites 

from Louisiana and Texas indicate that sugarcane planting is highly mechanized, information 

from Florida indicates that sugarcane planting may be conducted manually. See the enclosed 

document for further details. 

Because there is uncertainty regarding the method of planting sugarcane and whether 

post-application exposures to workers are likely, EPA continues to require the post-application 

dermal and inhalation exposure studies. If Bayer wishes to provide further information regarding 

the mechanized planting of sugarcane or to propose label language that would specifically 

preclude the use of ethoprop during hand planting of sugarcane, please contact EPA within two 

weeks of receipt of this letter. 
If you have any additional questions regarding this letter, please contact Monica Wait at 

(703) 347-8019 or via email (wait.monica@epa.gov). 

Enclosures: 

Sincerely, 

Michael Goodis, ef 

Risk Management and Implementation Branch III 

Pesticide Re-evaluation Division 

EFED Response to Registrant Submitted Waiver Request for a Freshwater Fish Full Life Cycle 

Toxicity Study for Ethoprop. January 11, 2011. J. Housenger. DP Barcode D384311. 

Ethoprop, PC Code 041101, DP Barcode 384788. Health Effects Division (RED) Review of 

Exposure Related Issues from 90-day Response to Ethoprop Generic Data Call-In. 

January 7, 2011. J. Dawson. DP Barcode 384788. 

CC: 

Mr. Jon Wood 

AMY AC Chemical Corporation 

4695 MacArthur Court, Suite 1250 

Newport Beach, CA 92660