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Date: September 27 , 2011 Subject: Response to Comments on Registration Review for Chlorpropham (CI PC) To: Eric Meiderhoff, Chemical Review Manager Office of Pesticide Programs Regulatory

Public Document (7502P) USA EPA 1200 Pennsy lvania Ave. NW Washington, DC 20460

- 0001 From: William "Bill" A

. Keim 604 Bell Mawr Place Barberton, Ohio 44203
Dear Mr

. Meiderhoff, From the information available on the EPA website, it appears that possibly some clarification can be helpful. Itis not possible t o address every item due to the lengthiness of the explanations

. **INTRODUCTION** My p ractical chemistry

began with the application (practice) of academic chemistry and mathematics when I joined PPG Industries as a Research Chemist in 1963. PPG was having s ome small success with its Sprout Nip product which is based on CI PC. Because of my hazard evaluation experience , I was asked to look at flame arrestors to control torching which can occur in the generation of the CI PC aerosol process

. Phy sical chemistry soon showed this would not work in a reasonable way . I n late 1970s Iwas given a "cold CI PC aerosol fogging project" which had been underway for some ye ars
. Cold fogging failed because the aerosol particles were too large (high residues in the bottom of the pile). This project let me see a commercial CI PC thermal aerosol application , the control experiment . Several things were obvious. First, the aerosol fog was very stable most of the time. Second, very large amounts of aerosol were being displaced from the storage bin that was being treated ( 2x or double treatments were standard)

. Third, it was amazing how well CI PC inhibited sprouting when so little was know n about what was going on in the application process. Once again the miracle of workable c hemistry

was demonstrated for me. The observation of an aerosol treatment during the period of Jan 5

- 9, 1981 led to my development of the Sprout Nip 7A formulation which was field tested in April 1982. S ubsequent s ignificant activities included : 1) I obt ained an understanding of potato storage distribution plugging by Sprout Nip application with Balivi, Boise, ID, in Jan 1985 . I then instructed all of the2 applicators to control the air velocit y used in the internal air handling s ys tem in order to improve the application process. 2) I carried out potato storage evaluation and recommended treatment procedures with Wilbur

- Ellis, Pasco, WA . to improve uniformity of the CI PC application. 3) I instructed the applicators on the use of reduced air flow planning for s torage treatments beginning with Fred Reeve, Riverhead, L ong Island, NY, in July 1986

. 4) I confirm ed the correctness of my guidance provided to Wilbur

- Ellis and Fred Reeve which resulted in me writing differential equations for a mathematical model which v er y accurately represents the CI PC aerosol application process . To date, this math represents the best engineering analy sis for the potato storage treatment

. 5) I unplugged Blad Farms potato storages and successfully treated the potatoes with CI PC aerosol using a very low air flow procedure in Dec 1987

. The n ormal CI PC treatment procedure that was used at this time had plug ged the storage's air recirculation sy stem

. No air could be recirculated through the potato pile. Immediate action was required. Th e duct sy stem had been re - designed by a major potato storage supplier

. The CI PC a pplicator had not been told about redesign

. Papers on my 7A formulation development and the aerosol treatment process mathematical model are published in ASTM STP 1312, 19 96. These papers published by ASTM ARE PEER REVIEWED prior to publishing

. Over the ye ars , potato storages were visited and evaluated with Sprout Nip applicators in much of the USA and Canada. I wrote the CIPC Product Chemistry which was part of PPG's re

- registration effort with EPA on CI PC in the 1980s. PPG sold the Sprout Nip business about 1987. Subsequent contact with the potato industry has confirmed that the technology that I introduced did exactly

what was expected of it. Significant aerosol application variables had been identified and some changes made. Significantly higher uniformly

distributed CI PC residues were obtained from the use of my innovations in the CI PC application science

. The risk of failure of the sprout inhibition was signi ficantly reduced which was the focus at the time

. There was, as expected, still copious amounts of CI PC displaced to the environment. As a result of a potato storage fire at Mountain King potato storage in Monte Vista, CO on 11/26/2000 , Bill Keim was onc e again involved with CI PC aerosol application. Iwas amazed at how little progress in the commercial aerosol application process there had been in the time that I was away ( **actually it looked like some significant backsliding was occurring**  )

. Discussio ns with my

sons resulted in our patent application of June 28, 2004 for using potato storage air in the aerosol generation process to control displacement

. U. S. Patent 7,635,665 for this technology was issued Dec 22, 2009 and is currently under reexamination by

the patent office. **The reexamination challenge**  **filed for Aceto by**  **attorneys indicates that the technology must really have some importance to the**  **potato industry otherwise the patent would be ignored.** The patent is needed to get3

financial support to implement th is technology w hich has significant public benefits

. Alternatel y, the EPA can support the implementation of this technology and/or any other technology

that KEEPS THE CI PC INSIDE THE COMMERCI AL STORAGE, PRI MARILY DURING THE CI PC INTRODUCTI ON PHASE for the CIPC aerosol application process to stored potatoes. So far any work on this technology

has only generated expenses

. **Environmental Fate and Effects Division (EFED) Response 04/14/11**  The Aerobic Soil Metabolism data can also be helpf ul to assess the fate of CI PC in potato storages and the potato samples taken for anal ys is. Residual soil life of CIPC for weed control is poor. Please make details of the work available to the public

. Thanks for recognizing the need to "minimize the escape of the compound". However, after normal housekeeping for a treatment, the majority of displacement is caused by the air pump (ty

picall y 140 cubic feet per minute) that is part of the aerosol generation equipment. Aerosol generation/introduction ti mes are generall y an hour or longer , and most displacement occurs during aerosol introduction to the potato storage. The aerosol hopefully persists as visible smoke in the air space of the storage for one or more hours after introduction. Potato air re

- c irculation should be maintained at a low rate during the period of deposition of visible aerosol. Deposition is over when a visible aerosol is no longer present (see the applicable phy sical chemistry)

. I worked continuously

with the applicators, partic ularly after 1980. PPG's label was adjusted to reflect technology improvements and to help control how the applicator did his job so that it was performed properl y . The use of application equipment was monitored. Still, the independence of the applicato r provided some surprises. After PPG sold the CI PC business unit, there were label changes made that actually eliminated most of the controls that PPG put in place . Today ’ s CIPC label essentially lets the applicator do whatever he wants when appl yi ng the CI PC as it has little if any controls on it that should be in place to protect the human population and the environment

. If displacement does not provide the answer for "where is the missing CIPC?" then degradation is a likel y candidate. I once obtaine d a residue of C IP C from a fan shroud in a potato storage that contained about 10% of the urea, di

- (3

- chlorophenyl) urea. Other expected degradates can be expected to remain in vapor state

. Some of these vapors will of course dissolve in the potatoes.
**H ealth Effects Division (HED) Response 17** 
**- May** 
**- 2011**  First Paragraph of the letter response on page 3

- 4: L arge amounts of CI PC are displaced because of the air pump used with ty pical aerosol generation equipment to pump outside air into the storage. Direct ions for use on the label do not address this air flow rate or the feed rate of CIPC for the aerosol generation equipment. **Directions for use of many**4

**pesticides provide guidance on the amount of water to be used in the applied spray. What is the differen**  **ce?** Fourth Paragraph under CI PC Application : There seems to be some confusion with respect to the residue data being discussed . Our concern is with residues used to evaluate a treatment with CI PC which are used to approve registration. We think that our comments with respect to these data are valid. Data for residues on potatoes as actually consumed are also important to the registration process, but are not the subject of our comments. Fifth Paragraph under CIPC Application and First, Second and Thir d Paragraphs under Sampling : Does the residue information used address the concerns that were expressed about handling potato samples? Data available to me does not appear acceptably useful to do mass balances on the application process. As a chemist, w e are trained that y ou can track where every

thing goes in a chemical reaction using a **MASS BALANCE** . The use of a mass balance is critical to evaluating the CIPC process and the CIPC registration process. **EP A needs to require all of its registered CIPC la**  **bel holders to submit a mass balance for the CIPC used during their**  **respective application processes**  **in order to know where**  **the CIPC goes**
**. Then it needs to check to make sure that this**  **process was performed properly.** Sixth Paragraph under CIPC Applicatio n: I t would be nice to think that the temperatures used for melting CIPC are kept reasonabl y low and the exposure times short. Temperatures exceeding 180 o F have be e n observed. This t ime at elevated temperature can last man y hours. Seventh Paragraph un der CI PC Application: Does OS H A have the ability to stop use of an EPA approved labeled product? **Technologies Sciences Group (TSG)**  **, Inc. Response Feb 18, 2011** Aerosol Application Process as described b y TSG: "The chlorpropham is applied from outside the building through a small tube into the building's ventilation ducts, using a sealed thermal fogging delivery s ys tem. During this application process, chlorpropham is not released into the environment." Clearly the exact equipment described b y TSG sho uld be that required for applications of CI PC and its specifi cation required by EPA on the product label. All Leco and Tifa based equipment use must be prohibited if they use an air pump to put outside air into the potato storage during aerosol generation which causes CI PC displacement

. TSG implies that they don’t use any

air pumps to pump outside air into the storage (if they did there would be gross displacement of CI PC from the storage)

. If so, then **TSG please share the necessary identification of thi**  **s aerosol generation equipment with the EPA so that it can be specified on the label.**  **Letter of Joel Micka, JMC Enterprises**  **, Inc. ,**  **of March 31, 2011**5

I think that I am aware of the aerosol generation equipment of JMC from discussions with Dr. Gale Kleinko pf. Ido not know specific details for the equipment. If I were to observe applications with JMC equipment, I expect that I could assess its capability and evaluate the total process (think total quality). From the claim for "virtually NO escape of CI PC during a potato storage thermal fogging treatment with our application technology " in the letter one would expect that the EPA would also want to have this equipment for application on CI PC specified on the product label along with TSG specified equipment

. **Letter Michael D. Lewis of April 1, 2011** Lewis knows about the air pumps on Leco and Tif a based aerosol generation equipment and the displacement of CI PC

. He also can be expected to know about JMC equipment. Surely some applicator has given him a cop y of my Sprout Nip Aerosol Application Field Handbook, issued in April 1987. Copies should also be available through records of some potato storage fire lawsuits. Iworked with lawy ers of a legal firm who understand the Handbook very

well. I cannot understand the scientific basis for most of the Lewis comments. Possibly

EPA needs to have both of us (or others equally qualified) as consultants to get a good understanding of CIPC application. I too think that CI PC is very critical to the potato industry . We just need to clean up displacement. We are going to have to accept some degradation. It is Mother Nature's way . She really

is the one who makes the rules. **Letter Dale E. Nelson, Nelson's Vegetable Storage Systems Inc., of**  **April 2, 2011** Nelson' s History : The 3 lb ai per gallon CIPC product was the Emulsifiable Product for water spray application to fresh market potatoes. **The methanol containing product was Sprout Nip 7A ,**  **formulated by me**  . PPG chose 7A over the solid material for the formulati on as it is essentially the same but is more easily handled as a liquid. Inow recognize that some degradation is much easier to control with 7A versus the 4A . Methanol replaced isopropanol and propy lene gl ycol in a 4A product. Using methanol , a Leco m achine can process 42 lbs of CIPC per hour versus 20 lbs of CI PC per hour with 4A. A Tifa machine can process about 63 lbs of CI PC versus 20 lbs of CI PC per hour with 4A.
**Comments** : Bill Keim started in 1986 the use of the necessary air velocit y control in a potato storage which occurs when fan speed is reduced.6

A r ealistic understanding of the autoignition process in CI PC aerosol generation process was developed. If the food grade adjuvant used by Nelson is clove oil, then Nelson can have more risk of autoignition.
I would expect that Nelson , who started as an applicator in Idaho in 1979 , should know me from my

visits to PPG Idaho applicators. It is very eas y to lose a lot of CI PC and still get a successful treatment. CI PC is amazing for potato spr out inhibition in spite of our application technology ig norance. If I knew the details of NVSS application process, then Ithink that I c ould provide a reasonabl y detailed scientific explanation for its success. It can be expected to be explained by reas onable phy sical chemistry . Part of BP's gulf oil release problem wa s due to the poor use of physical chemistry

. The remaining major area for improvement in CIPC use on potatoes appears to me to be how much to use in the application (the use rate) and the identification of potato and/or potato storage variables significant to the application with appropriate recommendation s
. Problems with understanding the application process and implementing the changes needed have made progress on these other issues pra cticall y non - existent. The use rate of CI PC can be expected to get much lower. The unnecessary requests for higher use rates are still being made. The goal needs to be to get to the use rate amounts necessary to get the necessary

sprout inhibition whi le minimizing any excess amounts.

CONCLUSION Can the need for EPA to "Hire knowledgeable consulting guidance on CIPC aerosol technology

for potatoes." be more apparent?

Sincerel y,

William A. Keim Keim Aerosol Technologies 604 Bell Mawr Place Barb erton, OH 44203 330

- 805

- 6453