Development of Model Fumigation Management Plan Utilizing Closed Loop Fumigation

Jim T Criswell
Ron Noyes
Oklahoma State University
127 NRC
Stillwater, OK 74078-3033
405.744.5531
405.744.6039 - fax

Project Duration: July 9, 2001 to September 30, 2003

	Request	Matching Funds (Not Required)
		Non-Federal	Federal
First Year Funding	20,000	10,594	0
Second Year Funding	20,000	10,594	0
Total Funding Request	40,000	21,188	0

Executive Summary

The Memorandum of Agreement between EPA and the registrants of aluminum and magnesium phosphide, requires users of phosphide fumigants to utilize a Fumigation Management Plan (FMP) to enhance worker safety. In this study, commercial elevator operators in Oklahoma and Texas will be targeted to be among the first in the region to develop FMPs. To reduce potential worker exposure to phosphine fumigants, Closed Loop Fumigation (CLF), a sealed phosphine recirculation system, will be utilized and included in the FMPs. CLF will assist in reducing worker and bystander exposure while minimizing fumigant use by allowing for phosphide application, monitoring concentration levels and monitoring any gas leakage to be conducted outside the fumigated grain bin and advance the increased adoption of the FMP due to the above safety reductions.

Two commercial elevators each in Oklahoma and Texas will be selected for FMP and CLF development applications. Efforts will be made to select elevators with existing CLF systems. If elevators have CLF installed, an effort to improve the sealing of storages will be made. Two other non-CLF commercial elevators in each state will also be used as controls.

FMPs will be developed and implemented for each of the eight elevators. Gas levels will be recorded both inside and outside the storage units using electronic phosphine monitoring devices. Measurements will include identified areas on the FMP, the grain mass, outside the storages during the fumigation, and the aeration or gas venting process including monitoring at the property line and amount of fumigant used.

Expected outcomes include adoption of the FMP, increased adoption of CLF and reduced worker exposure, reduced phosphine use, and increased documentation of phosphine levels through implementation of FMPs.

Objectives

Conduct educational programs on FMP development and implementation.

Conduct educational programs featuring Closed Loop Fumigation sites.
Identify or establish four closed loop systems (two in OK and two in TX) at commercial grain elevators.
Identify four non-CLF systems (two in Ok and two in TX) at commercial grain elevators.
Develop and conduct field days after fumigation seasons.
Document FMP development and implementation, fumigant costs, CLF impacts in Oklahoma and Texas, phosphine gas monitoring levels, and efficacy of fumigant compared to elevators not using CLF.

Justification

Objective 1:
Phosphine fumigation is a critical management tool for Oklahoma and Texas elevator managers. Phosphide fumigant is the key fumigant and insect management tool in U.S. grain storage is going through re-registration. The present methods of application are to introduce the fumigant pellets onto a grain stream via an automatic dispenser or for employees to hand apply the fumigant to the grain surface. The automatic dispenser is used in concrete facilities while employees may be utilized to hand apply phosphine pellets or tablets in corrugated steel bins and flat storage installations. Issues include potential worker respiratory exposure, genetic mutation, amounts of the fumigant used, efficacy and insect resistance to phosphine.

Through the educational programs defining what is required to develop a FMP and how to implement and utilize the FMP for safe and efficient phosphine use, elevator managers will become more receptive and agreeable to developing and implementing a FMP.

The educational programs will detail what each state desires in a model FMP and how to clearly develop and implement such a safety plan.

Objective 2:
For elevators that do not have CLF, educational programs will be conducted to explain the worker safety, phosphine application and cost benefits of such a system. Information and engineering assistance will also be provided for designing and installing CLF at the four test elevators.

With the use of CLF, the FMP will be easier to design and implement due to the reduced exposure potential to elevator workers.

Objective 3:
After four elevators are identified with CLF, these elevators will be paired with corresponding nearby commercial elevator of similar size, storage unit design and treatment history that do not have CLF.

By having comparison elevators, we will be better able to document differences in FMP development, phosphine use and potential worker exposure.

Objective 4:
Field days will be scheduled at each location during each year of the project. At the field days, other elevator managers will be informed of the progress and benefits of a FMP and CLF. Proper safe use of phosphine fumigants will be discussed, demostrated and development of the FMP will be stressed. This will include sharing information on safety and cost benefits of a proper FMP learned from the four test elevators.

Objective 5:
Documentation of costs associated with the development of a FMP and CLF will be recorded and shared with other elevator facilities. Included in the documentation will be the time spent and levels of phosphine detected under a FMP and fumigation efficacy utilizing CLF and non-CLF.

Literature Review

Oklahoma and Texas produce 13% of the hard red winter wheat and 33% of the grain sorghum in the United States (USDA-NASS 2001). Most of these grains are stored locally in corrugated steel bins or concrete silos at commercial grain elevators.

Elevator managers typically make 2.6 applications per year (Cuperus et al. 1990). Fumigants, by their design, are a dangerous substance. There are several required safety practices for their safe application and use (Leesch et al. 1995). Fumigators often have failures due to poor application and lack of sealing which contributes to growing pesticide resistance by stored grain insects. Presently, few elevator operators follow all the required EPA safety guidelines (Cuperus et al. 1990, Kenkel et al. 2001). Through the development and implementation of FMPs, elevator managers will be better equipped to identify potential worker exposure areas and address the situation(s). Elevator managers will also be better equipped to identify potential problems in their present fumigation programs and to improve the fumigation program to avoid leakage and potential worker exposure. An ideal safety approach to improving phosphine application is by installing and using a closed loop system (CLF) (Noyes et al. 1995). CLF has been shown to achieve ideal fumigant distribution with almost zero worker exposure (Noyes et al. 1995).

CLF is a technology that drastically reduces worker exposure, increases efficacy, and typically has a pay-pack in two to four years. Yet due to the perception of cost and complexity use this technology relatively few commercial elevators have adopted this technology and IPM tool. Less that 1% of U.S. elevators presently use CLF (Kenkel et al. 2001), however, about 10% of Oklahoma elevators now use CLF.

Approach and Methods

Two elevator facilities each in Texas and Oklahoma will be selected for the program. These four facilities will either have existing CLF or will have CLF installed. The project leaders and consultant(s) will work with the elevator managers to develop the required FMP using CLF as a central method of worker exposure reduction. We will select four additional (two in each state) elevators that do not have CLF as comparison elevators. The project will involve the Cherokee Strip Chapter of GEAPS (Grain, Elevator and Processor Society) in Guymon, OK and the Tri-State GEAPS Chapter in Amarillo, TX. The GEAPS chapters will be kept informed of the program progress and findings. Through this avenue information will be further expanded to the stored grain community.

We will record the time spent developing and implementing the FMP for each of the eight elevators. We will record the time required to conduct gas monitoring under the FMP and the cost of gas monitoring. This will include both the equipment and personnel time cost, and the amount of fumigant used and its cost - including application cost.

Gas monitoring will be done with electronic monitoring equipment such as the ATI Porta Sens, Dräger Mini-Warn or Lumidor with periodic comparisons by glass tube sampling using Dräger or MSA hand sampling pumps. Grain mass fumigant levels will be taken by having poly tubes positioned at different depths within the grain mass and storage head-space and gas samples taken from the top of the poly tube ends that will be located outside the fumigated storage units. Gas samples will also be taken at selected distances (e.g. 5, 10, 20, 40, 80 ft) down wind during fumigation and aeration and at the property line during fumigation and aeration.

The cost of gas monitoring will be documented and comparisons made between CLF and non-CLF facilities. Phosphine use amounts and efficacy of the fumigations will also be recorded. Efficacy will be measured by strategically placing perforated vials of lesser grain borers (Rhyzopertha dominica) and rusty grain beetles (Cryptolestes ferrugineus) in each storage unit and removing these samples after venting. The lesser grain borer is the major grain damaging insect while rusty grain beetles are insects commonly found in grain and do not damage whole grain. Placement of these vials at various locations in the grain mass during fumigation will provide a good indicator, along with phosphine uniformity readings of the grain mass, of the fumigation.

Comparative cost of FMPs and phosphine use will be made between the four FMP "test elevators" and the four neighboring non-FMP "check" elevators.

Throughout the study, insects will be monitored in the grain bins utilizing the WWII probe trap. This trap is placed in the upper six feet of the grain mass and collects insects as the insects travel through the grain mass. Probe traps provide a good monitoring guide on insect populations within a grain mass.

Impact Assessment

Surveys of all commercial grain elevators in TX and OK were conducted in 1998 to gain information on the population of elevator operators' practices. This information will act as base line data. At field days, surveys of participants will document differences in use of phosphine fumigants. A repeat statewide elevator survey, using the 1998 survey instrument, will be completed in 2003 to compare to compare mangers of CLF facilities to managers to non-CLF facilities to document change in potential worker exposure, phosphine use and implementation of FMP.Success will be measured by the implementation of FMPs and the documentation of reduced exposure of workers to phosphine fumigant and reduced use of phosphine fumigant by the elevators utilizing a FMP and CLF.

Appendix A. Literature Cited

Cuperus, G.W., R.T. Noyes, W.S. Fargo, B.L. Clary, D.C. Arnold & K. Anderson. 1990. Successful management of a high risk stored wheat system in Oklahoma. Amer. Entomol. 36:129-134.

Kenkel, P., R.T. Noyes, G.W. Cuperus & J.T. Criswell. 1993. Economics of closed loop fumigation. Okla. State Univ. Coop. Ext. Serv. FS-219.

Kenkel, P., J. Criswell, R.T. Noyes. 2001. 2001 Elevator survey in TX, AR, & OK.

Leesch, J., G.W. Cuperus, J. Criswell, J. Sargent, & J. Mueller. 1995. Practical fumigation considerations. pps 139-152. In Stored product management. Okla. State Univ. Coop. Ext. Serv. Circ. E-912.

Noyes, R.T. 1995. Closed loop fumigation systems pps 153-161. In Stored product Management. Okla. State Univ. Coop. Ext. Serv. Circ. E-912 (Revised).

USDA-NASS. Jan. 2001. Crop Production: 2000 Summary. CR PR 2-1 (01)c.

Zettler, L. & G.W. Cuperus. 1990. Pesticide resistance in Tribolium and Rhyzopertha in Oklahoma. J. Econ. Entomol. 83:1677-1681.

Appendix B. Timetable

July 2001 - September 2001

Locate eight cooperating elevator managers in Oklahoma and Texas. Four for the development of the Fumigation Management Plan & Closed-Loop Fumigation and four without.

October 2001 - December 2001

Install CLF systems if it is not present. Obtain past fumigation records and other insect management data from the eight facilities. Begin development of FMP.

January 2002 - March 2002

Develop and implement FMP on the four test facilities.

April 2002 - January 2003

Document fumigations under the FMP & CLF. Implement FMP at the four elevators and review FMP and functionality. Process data records taken and compare with non-FMP/CLF elevators in project. Host field days - one in Texas and one in Oklahoma on project.

February 2003 - September 2003

Continue program, record keeping and data comparisons include review of FMPs. Host two field days - one in Texas and one in Oklahoma on project.

Appendix C. Major Participants

Dr. Jim T Criswell OSU Pesticide Coordinator

Jim Criswell is responsible for pesticide applicator education programming in Oklahoma. He will assist the project in the development of FMPs and the coordination of FMPs with the Oklahoma Department of Agriculture and the Texas Department of Agriculture so FMPs meet state regulatory standards.

Mr. Greg Cronholm Texas A&M IPM Extension Entomologist

Greg Cronholm is an area entomologist for Texas A&M University. He is located in Plainview, TX which is close to Lubbock, TX. There are numerous grain elevators in this area and Greg works with them on pest management.

Dr. Gerrit Cuperus OSU Entomology Extension

Gerrit Cuperus is an extension entomologist working in stored grain at Oklahoma State University. He has worked over 10 years in the stored grain management program. He will advise on the IPM aspect of the program.

Dr. Ronald Noyes OSU Extension Agricultural Engineer

Ron Noyes has worked with grain storage facilities for over twenty years. He will be the design engineer for installing CLF. He will also assist in trouble shooting fumigation questions.

Dr. Tom Phillips OSU Entomology Research

Dr. Phillips is a researcher working on stored product insects and is recognized nationally and worldwide for his research on stored product management of insects.

Appendix D. Project Budget

Budget Category	Grant Funding	OSU Match	Total Funding
Personnel Graduate Student	0	10,000	10,000
Fringe Benefits	0	626	626
Travel	4,770	0	4,770
Equipment	6,000	0	6,000
Supplies	2,770	0	2,770
Contractual Consultants	20,000	0	20,000
Total Direct Costs	33,540	10,626	44,166
Indirect Costs	6,460	10,562	17,022
Total	40,000	21,188	61,188

Personnel

A graduate student will assist with the day-to-day workings of the program and to coordinate with the PI's communication between Oklahoma State University, Texas A&M and the elevator managers.

Travel

These funds will be provided to the co-investigators, contractual and Greg Cronholm to assist in implementing and servicing the elevator managers.

Equipment

This includes two electronic phosphine monitoring devices and their sensors. OSU has two electronic phosphine monitoring devices. The addition of two more will greatly facilitate success of monitoring and documentation of phosphine gas levels by allowing their usage by the cooperating elevator managers.

Supplies

Supplies include paper, printing costs, data recording forms, phosphine glass monitoring tubes, electronic phosphine sensors calibration, sealing material, WWII probe traps, poly tubes, tape, etc.

Consultants

We will contract with Jerry Meers of Lubbock, TX and Stan Miller of Enid, OK. They are stored grain industry consultants. They will act as liaisons between the stored grain managers and the Major Participants. They will also advise us on the practical development of FMPs and trouble shoot FMPs to make them more usable.