Canadian Leadershipin the Development ofMethyl Bromide Alternatives

Alternatives to Methyl BromideFumigation of Empty Ship Holds

Government Gouvernementof Canada du Canada

Alternatives to Methyl Bromide Fumigation of EmptyShip Holds.

November 1999

Prepared for the:Environment BureauAgriculture and Agri-Food Canada

Editors:

Paul Fields and Sheila Jones

Contributors:

Robert Brigham, Denis Bureau, Roger Cavasin, Paul Fields, Sheila Jones, Nancy Kummen,Dorothy Laidlaw, Brett MacKillop, Bernie McCarthy, John McIssac, Mike McLean, Michel Maheu, Mark Matthews, Dave Mueller, Don Shaheen, Martin St-Pierre, Blaine Timlick, Alan Van Ryckeghem and Murray Weightman.

This publication is also available on the world wide web at http://www.agr.ca/policy/environment

Photo credits: Roger Cavasin, Paul Fields, David Mueller and Murray Weightman

Acknowledgement

This was truly a collaborative study involving the cooperation of Canadian and American companies, the government of Ontario and various Canadian federal departments. In addition to the numerous direct participants in the study, we would also like to acknowledge the following people: Pierre Beauchamp, Geoff Cutten, Stephen Murch, Noel White and Larry Zettler. The affiliations and coordinates of each of the collaborators are listed in the Appendix B.

Graphic Design and Printing:Bonanza Printing & Copying Centre Inc., Ottawa, ON

Printed in Canada on Recycled Paper.

Table of Contents

FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2TABLE HEADINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5METHOD

The Ship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Sealing the Holds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Pressure Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Treatments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Insect Bioassays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7Corrosion Assays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8Recapture of Methyl Bromide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8ECO2FUME™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9Horn Generator / Magtoxin® Granules System . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

RESULTSTemperature, Relative Humidity and Gas Concentrations . . . . . . . . . . . . . . . . . . . . .12Insect Bioassays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13Corrosion Assays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14Recapture of Methyl Bromide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

DISCUSSIONRecapture of Methyl Bromide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16ECO2FUME™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17Horn Generator / Magtoxin® Granules System . . . . . . . . . . . . . . . . . . . . . . . . . . . .17Potential Use in Other Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17Other Alternatives to Empty Ship-Hold Fumigations . . . . . . . . . . . . . . . . . . . . . . . .18

REFERENCESAPPENDIX A: Experimental Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20APPENDIX B: List of Collaborators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

1

Foreword

The Montreal Protocol on Substances that Deplete the Ozone Layeris a global agreement intendedto protect the ozone layer by reducing the production of ozone depleting substances. Developedcountries that are signatory to the Montreal Protocol- this includes Canada and the United Stated -must completely phase-out the consumption of methyl bromide by the year 2005.

Presently, the Montreal Protocolexempts the use of methyl bromide for quarantine and pre-ship-ment purposes as it is essential that the movement of pests between countries be prevented.However, as citizens of the planet, it behoves all of us to look for effective alternatives to everymethyl bromide application.

To maximize research collaboration and the development of alternatives, Agriculture and Agri-FoodCanada and Environment Canada created an informal working group on methyl bromide alterna-tives. Part of the mandate of this group is to assist research scientists and industry to work togetheron common problems and projects and to share research results with the public at large. Thisindustry/government working group identified the lack of alternatives to present ship hold fumiga-tions for quarantine and pre-shipment purposes as both a necessity and an opportunity. This reportrepresents the efforts of a successful collaborative effort involving a variety of service and productoriented Canadian and American companies, the Ontario provincial government and several federaldepartments.

The results of this report show that inroads can be made into reducing the amount of methyl bro-mide emitted from ship hold fumigations. However, it is clear that the results of this field trial canbe applied beyond ship holds. For example, methyl bromide with recapture or phosphine could besuccessfully employed in fumigation situations ranging from small containers to well-sealed ware-houses.

My sincere thanks to all the participants in this field trial for their enthusiasm, professionalism, anddedication in this collaborative effort to address the issue of ozone depletion.

Dr. Douglas D. HedleySenior Executive DirectorPolicy BranchAgriculture and Agri-Food Canada

2

SUMMARY

Although the United NationsMontrealProtocol on Substances That Deplete theOzone Layerpresently exempts the use ofmethyl bromide for quarantine and pre-shipment purposes, many countries questionthis exemption. There is concern over theincreasing use of methyl bromide for quaran-tine and pre-shipment purposes globally. Thecost of methyl bromide has increased in thelast few years, and as the phase-out dateapproaches we expect the price of methyl bro-mide to continue to increase. To address theseconcerns the members of the CanadianIndustry / Government Working Group onMethyl Bromide Alternatives decided toexamine alternatives to methyl bromide fumi-gation of empty ship holds. We tested threemethods of controlling insects in empty shipholds: methyl bromide with recapture, phos-phine in cylinders (ECO2FUME™) and

controlled generation of phosphine (HornGenerator with magnesium phosphide).

Vials containing adults and eggs of the rustygrain beetle, lesser grain borer, rice weevil andthe red flour beetle, common insect pests ofstored products, were placed in each of theship holds. One hold was treated convention-ally with 5400 ppm methyl bromide, a secondwith 500 ppm phosphine using ECO2FUME™as a source of phosphine, and a third hold with1000 ppm phosphine using the HornGenerator as a source of phosphine. After 32hours, all treatments controlled 100% of theadults. The phosphine fumigations controlledat least 94% of the eggs after 32 hours, 99%after 48 hours and 100% after 72 hours. Eggsare one of the most difficult stages to controlwith fumigation. The egg mortality was onlyslightly higher with phosphine at 1000 ppmcompared with 500 ppm.

The temperatures during this trial were warm(highs above 30˚C, with an average of 23˚C).However, ships often must be fumigated incooler weather. Phosphine efficacy is reducedmore by low temperatures than is methyl bro-mide. One possible way to overcome the lowtemperature sensitivity of phosphine would beto preheat the ship before fumigation.

The methyl bromide recapture technique cancapture approximately 80-90% of the methylbromide used, and would add approximately$CAN 2 000/ 75 kg (160 lb.) of methyl bro-mide recaptured based on this demonstrationproject. Larger capacity recapture units wouldhave to be built before this method could beused commercially for ship holds. The advan-tage to this method compared with others isthat there are few regulatory impediments, thecaptured methyl bromide can be reused, itreduces the human health risks in the vicinityof the fumigation site and it significantlyreduces the amount of methyl bromidereleased to the environment.The Canadian Trader docked in the Toronto Harbor

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Neither ECO2FUME™ nor the Magtoxin®Granules (magnesium phosphide formulationfor the Horn Generator) are registered inCanada, although the process has begun forMagtoxin®. The main impediment to usingphosphine in temperate climates would be thelonger exposure periods needed to control insectsat low temperatures.

We also examined the corrosiveness of phos-phine to metal. Copper strips showed corro-sion after exposure to both phosphine treat-ments. Although phone jacks showed no visi-ble signs of corrosion, a computer held at 500ppm did stop functioning after 25.5 hours, and

examination revealed that failure resulted fromthe thinning and overheating of the lead to anintegrated circuit chip. However, given theheavy steel construction of ship holds, corro-sion as seen in this trial should not be a con-cern.

In conclusion, each of the three treatmentscould be used to limit the methyl bromideemissions from ship hold fumigations. Thesemethods presently cost more than methyl bro-mide treatments, and there are some regulato-ry issues that would have to be addressedbefore these methods could be used in shiphold fumigations in Canada.

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Table Headings

Table 1 The number of grain ships inspected, fumigated, sprayed with insecticide, or recleaned in Canadian ports.

Table 2 The temperatures of ship bulk heads and vials containing insects at three different levelsin the holds containing different treatments.

Table 3 The concentrations of fumigants in the ship holds.

Table 4 Survival of adults in untreated hold immediately after taken from ship hold.

Table 5 Survival of adults in untreated hold one week after taken from ship hold.

Table 6 The number of adults per vial that emerged 5 weeks after vials were exposed to treat-ments for 32, 48, and 72 hours.

Table 7 The survival of eggs in treated ship holds as compared to eggs in the untreated ship hold.

5

Introduction

The United Nation has identified methyl bro-mide as an ozone depleting substance. All developed countries signatory to the MontrealProtocol on Substances that Deplete the OzoneLayer(Anon. 1998) must phase-out its use bythe year 2005. Although the Montreal Protocolpresently exempts the use of methyl bromidefor quarantine and pre-shipment (QPS) purpos-es, many countries question this exemption.There is concern over the increasing use ofmethyl bromide for quarantine and pre-ship-ment purposes, as they make up about 22% ofthe methyl bromide consumed globally.Furthermore, as countries approach the phase-out date and the amount of methyl bromideproduced lessens, the price of methyl bromidefumigations for all purposes is expected toincrease dramatically. However, it is essentialthat proven and internationally accepted alter-natives exist to meet quarantine and pre-ship-ment requirements.

The current definition used by the MontrealProtocol for quarantine applications is: “...to prevent the introduction, establishment and /orspread of quarantine pests, or to ensure their official control, where official control is thatperformed by, or authorized by a national plant,animal or environmental protection orheath authority.” For pre-shipmentapplications the definition is: “...thoseapplied directly preceding and in rela-tion to export to meet the phytosani-tary or sanitary requirements of theimporting country or existing phy-tosanitary or sanitary requirements ofthe exporting country.” Proposedrefinements of the definition of pre-shipment would limit it to treatmentsmade 14 days or less before shipment.

Members of the Canadian Industry /Government Working Group onMethyl Bromide Alternatives believedthat an investigation into alternatives

for ship hold applications would demonstratethe effectiveness of potential alternatives,reveal whether or not they are currently regis-tered for use in Canada, and would providedata on their associated costs. Furthermore,these techniques may be useful in other situa-tions where methyl bromide is used to controlinsect infestations.

Canada has a long-standing policy of inspect-ing all ships before loading grain. TheCanadian Grains Act(85-3) does not allow forgrain to be loaded into infested vessels. If livestored-product insects are found in ship holds,three possible actions are required dependingupon the nature of the infestation; cleaning ofthe hold, cleaning of the hold followed by aspray of contact insecticide (malathion), orcleaning followed by fumigation. About 1000ships are inspected each year in Canada withabout 2% of them requiring fumigation(Table 1). Methyl bromide is the fumigant ofchoice because it is a rapid acting insecticide.

An experiment onboard a ship would provide aunique opportunity to simultaneously comparethe effectiveness of three alternatives underidentical field conditions. The corrosiveness ofphosphine was also examined.

6

Methods

The shipThe field trial was conducted onboard the“Canadian Trader” a 223 metre (730 ft.),lake-going ship designed to carry approxi-mately 29,000 tonnes (6600 ton). Figure 1describes the dimensions and the layout of theship. Hold numbers 1, 4 and 6 were used forthe treatments. The “Canadian Trader” waschosen for its similarities in structure andfunction to ocean-going ships.

Sealing the holdsAt the base of each of the bulkheads (walls)separating adjacent holds were two small tun-nels (60 cm x 45 cm, 24 in. x 16 in.) thatallow drainage between holds. In the fumigat-ed holds, these tunnels were sealed with 6 mmpolyethylene, glue and duct tape. The ship’ssteel hatch covers were clamped in place andtheir edges were sealed with 7-cm-wide (3 in.)duct tape. The manholes were covered with 6mm (0.25 in.) polyethylene and sealed withduct tape. Tubes for introducing and sampling

fumigants were passed through the polyethyl-ene covering the manholes, as were the ropes used for retrieving the insect and copper (forcorrosion study) samples.

Pressure testingPressure testing is useful to give an indicationof the relative level of sealing between holdsand to determine the effectiveness of eachseal. A high pressure blower (1/2 hp) was

used to form a positive pressure of0.38 kPa (1.5 inches of water) ineach test hold. Once pressure wasachieved, the blower was turned off,the blower tube sealed and the timeto drop from 0.38 to 0.19 kPa wasmeasured. In holds 1, 4 and 6, thepressure dropped by 50% in 6.1,13.5 and 6.0 minutes, respectively.Initially, the pressure could only bemaintained briefly in hold 4, there-fore, the drainage tunnels at the

base of the hold were resealed and the pres-sure test redone. These results indicate thatthere was a tight and secure enclosure byfumigation standards. The Australian pres-sure testing standards are a half life of fiveminutes (Banks 1984).

TreatmentsThere were three treatments: methyl bromideat approximately 5400 ppm (21 oz/1000 ft3 )with recapture after one day (hold 1);Manholes covered with polyethylene and sealed with duct tape

Pressure testing the seals of the ship holds prior to fumigation

Figure 1: The “Canadian Trader”, size of holds, placement of treatments anddeployment of test insects.

7

phosphine at 500 ppm applied using theECO2FUME™ method (hold 4); and phos-phine at 1000 ppm applied using the HornGenerator with magnesium phosphide (hold6). Hold 3 was used as the untreated control.The fumigations were begun between 12:30p.m. and 12:50 p.m. on Sunday, June 6, 1999.

A Fumigant Gas Analyzer (GO-MACInstrument Co.) was used to measure themethyl bromide in the ship hold. We used aPortaSens (Analytical Technologies) to mea-sure phosphine in the phosphine treatedholds, and a Silo-Chek (Canary Co.) to mea-sure phosphine in the untreated hold. For theboundary line sampling we used a DraegerPAC III, which is sensitive to phosphine at0.01 ppm. Sampling was done at 6 hourintervals in front of a recycling warehousewhich was 11 m (35 ft.) from the ship and 22m (70 ft.) from ship hold openings. Also thesingle crew member working on the ship wasequipped with a Draeger PAC III during thefumigation. Samples were also taken in thetunnels that were beside the ship holds andabove the wing tanks.

Insect bioassaysFour insects were used in the bioassay: rustygrain beetle (Cryptolestes ferrugineus(Stephens)), rice weevil (Sitophilus oryzae(L.)), red flour beetle (Tribolium castaneum(Herbst)), and the lesser grain borer(Rhyzopertha dominica(Fabricius)). Testvials of each species were prepared. Twenty-five mixed aged adults were placed in plasticscreen-topped vials containing 10 g of wheat,with 20% being cracked grain, on Wednesday,June 2. The vials were held at 30˚C for 24hours, then transported from Winnipeg toToronto (approximate temperature 20˚C) andplaced in the ship holds on Saturday, June 5.This incubation period before treatmentenabled females to lay eggs, but wasinsufficient to allow the eggs to hatch.Consequently, all vials contained both eggsand adults.

Vials were taped to ropes. A set (fourspecies, four replicates/species) was locatedat the bottom (12 m (36 ft.) from top), mid-way (6 m (18 ft.) from top), and at the top ofeach hold. Three ropes, each with three setsof vials, were hung from the manhole. Onerope was pulled from each hold 32, 48 and 72hours after the start of the fumigation. Forthe methyl bromide treatment, there was onlyone rope that was pulled at the completion ofthe methyl bromide fumigation (32 hours)For sampling the phosphine treatments at 32and 48 hours, a cut was made in the polyeth-ylene cover, the rope with attached vials waspulled from the hold and the polyethylenecover was resealed with duct tape.

Temperatures were measured using thermo-couple wires connected to a data logger thattook temperatures every ten minutes andrecorded the mean temperature every hour.Temperatures were taken at six locations in

Placement of the insects in a ship hold

8

each of the four holds - at the bottom, middleand top positions, attached to the bulkheads,and attached to vials. Relative humidity wasmeasured in hold 4, at the top using a capaci-tive type RH ± 2% sensor attached to the datalogger, and at the bottom using an ACRSmart Reader 2 with temperature and RHsensor ± 4%.

After each rope was removed from a hold,adults were sieved from the wheat from eachvial, the survival rates were noted and theadults placed back on clean wheat in newvials. These vials were held at about 20˚C in

the ship crew quarters until Wednesday,June 9 and then transported to Winnipeg onFriday, June 11 where they were held at 30˚C.One week after the insects had been removedfrom the holds, the number of live and deadadults was reassessed to detect delayed mor-tality or revival of insects that could havebeen counted as dead but were in a fumigant-induced stupor. To assess egg survival, thewheat that was held in the holds was placedat 30˚C on June 11, and the number ofemerged adults counted after five weeks.

Corrosion assaysIn order to measure the corrosiveness ofphosphine to metal, copper samples and elec-trical components were examined. Copperstrips (1 cm x 3 cm, 0.5 in. x 1.25 in.) werecleaned with concentrated hydrochloric acid,weighed and numbered. At the bottom andtop levels of each rope a vial containing three

copper strips and a male telephone jack con-nector was attached. Also three 15 m (45 ft.)telephone extension cords, with male andfemale connectors joined were taped to theend of each rope. At the end of the trials thevials and connectors were sent to Dr. RobertBrigham, a metallurgist, for assay. The cop-per strips were weighed as received, cleanedwith hydrochloric acid to bare metal, dippedin absolute alcohol, dried and reweighed todetermine weight loss. The telephone exten-sion cords were cut, and the resistance acrossthe telephone jack connection was monitoredas a function of time generally followingASTM B 539, Test Method C(3). This “drycircuit testing” technique uses a potential of0.020V and limits the current to 100mA. AnEG&G Princeton Applied Research Model363 potentiostat was used to supply the con-stant DC voltage and to monitor the resultantcurrent (Brigham 1999).

A 486 mother board was placed at the bottomof hold 6 (1000 ppm phosphine), and recov-ered at the end of test for examination. Afunctioning Zenith computer with 512 K ofRAM and monitor was placed inside the sec-ond manhole of hold 4 (500 ppm phosphine).Power and key board cables were passedthrough the clear polyethylene so that com-mands could be typed into the computer todetermine possible effects from exposure tophosphine.

Recapture of methyl bromideBefore hold 1 was sealed, a 0.9 cm (0.38 in.)diameter plastic delivery tube was taped tothe top half of the access ladder for therelease of methyl bromide. Three recoveryhoses, 5 cm (2 in.) in diameter, were insertedinto the hold. To optimize recovery, the inletswere spread across the bottom of the hold.The three hoses were connected to the firststage collector that contained a zeolite molec-ular sieve. The recovery blower was posi-tioned after the collectors to provide for saferecovery. Both the collectors and the blowerwere on a flatbed truck parked on the dock.

Counting the survival of the insects in each vial

9

In 30 minutes, 91 kg (200 lb.)of methyl bro-mide was released into the hold. After fourhours, the hold seals were double checked andan additional 22.5 kg (50 lb.) of methyl bro-mide was introduced in order to reach thedesired concentration (5400 ppm). A fanplaced on the bottom of the hold ran for thefirst six hours of the fumigation to facilitate indistributing the methyl bromide throughoutthe hold.

Methyl bromide recapture was carried out byCryo-Line Supplies Ltd. of MississaugaOntario, Canada. It began 24 hours after thestart of the fumigation at 1:00 p.m. Monday,June 7. The 25 hp blower powered by aportable generator created 6.8 kPa (2 inchesof mercury) of pressure in the hold as it with-drew the air at 470 L/sec (1000 cfm) towardthe collectors. After two hours, the recapturewas halted for 1.5 hours because of a severethunderstorm. The recapture process wasstopped at 8:30 p.m. when methyl bromidewas detected coming out the exhaust of the

collector sieves. The concentration of methylbromide remaining in the ship hold at 9:00p.m. was 390 ppm, which is less than 10% ofthe initial concentration. The zeolite in thecollector can absorb four to six percent of itsweight in methyl bromide. The amount ofmethyl bromide recovered was determined byweighing the truck and sieve at a commercialweigh scale before and after the recapture.

ECO2 FUME™ECO2FUME™ fumigant gas is a nonflamma-ble, premixed, cylinderized mixture of phos-phine and carbon dioxide, and is produced byCytec Canada Inc. located in Niagara Falls,Ontario, Canada. ECO2FUME™ fumigant isa gaseous mixture of 2% phosphine byweight, (2.6% by volume) in carbon dioxide.Phosphine is flammable in air at 1.79% (Bond1984), but if phosphine is below 2.75% v/v incarbon dioxide, then it is nonflammable in allproportions of air (Pearson 1995).

We used 44 L (1.5 ft3) high-pressure cylinderswhich contain a total of 22.7 kg (50 lb.) ofgas; 0.45 kg (1 lb.) of phosphine in 22.23 kg(49 lb.) of carbon dioxide. This size cylinderwill fumigate 652 m3 (23 060 ft3) of space at25˚C (77˚F) to a concentration of 500 ppmphosphine. Hold 4 being 6220 m3 (219 720ft3) ) required 9.5 (22.7 kg.) cylinders ofECO2FUME™ to establish the target concen-tration of 500 ppm.

For this application two manifolds were con-structed. Each manifold was capable ofattaching four cylinders of ECO2FUME™.They were constructed of stainless steel 6mm(1/4 in.) high pressure tubing and fittings andeach manifold was equipped with a pressuregauge. A 15-m (45-ft.) length of 6 mm (1/4in.) copper tubing was attached to the end ofeach manifold. Copper tubing was selectedbecause of its flexibility, making transporta-tion and installation easy. The two lengths oftubing were run from the cylinder manifoldsto the manhole, and were securely attached tothe access ladder 2 m (6 ft.) below the

The methyl bromide recapture unit of Cryo-Line Supplies Inc.

Methyl bromide treatment

10

manhole top. ECO2FUME™ was chosen forthis trial because of its ease and rate of appli-cation, and its effectiveness as a fumigant.ECO2FUME™ and the Horn Generator /Magtoxin® Granules System are differentfrom traditional phosphine fumigations thatuse aluminum phosphide or magnesium phos-phide in pellets or plates. These solid formula-tions of phosphine react with humidity in theair to cause the release of phosphine gas, andhence require more time to reach targetconcentrations.

The first four ECO2FUME™ cylinder valvesof one manifold were opened to begin thefumigation, but the application rate wasreduced to one cylinder at a time. Thisallowed air to slowly be displaced from thehold and minimize the pressure on the seals.A single cylinder will completely discharge inapproximately five minutes. The release of allnine ECO2FUME™ cylinders was spaced overa 90-minute period to establish the desired 500ppm phosphine concentration.

Part of a tenth cylinder of ECO2FUME™ wasapplied 21 hours into the fumigation to top upthe phosphine concentration. The balance ofthis tenth cylinder was added 69 hours into thefumigation. Topping up allowed maintenanceof the desired phosphine concentration therebycompensating for the "breathing" of the holdfrom temperature swings.

Horn Generator / Magtoxin® GranulesSystemThe Horn Generator is an automated devicewhich is produced by Degesch de Chile. TheHorn Generator is a specialized reactionchamber where a high purity magnesiumphosphide product reacts with water toproduce phosphine. This reaction is carriedout under an atmosphere of carbon dioxide.The phosphine / carbon dioxide mixture isthen injected through a recirculation systeminto the structure to be fumigated. The chemi-cal reactions that occur within the HornGenerator are as follows:

Mg3P2 + 6 H2O 2 PH3 + 3 Mg(OH)2

magnesium water phosphine magnesiumphosphide hydroxide

Mg(OH)2 + CO2 Mg CO3 + H2O

magnesium carbon magnesium waterhydroxide dioxide carbonate

Degesch Magtoxin® Granules, containing96% magnesium phosphide as a flowablepowder, is designed and formulatedspecifically for use with the Horn Generator.Granules are supplied in 850g (1.9 lb.) flasks(liberating 411g (0.9 lb.) of phosphine).Applications for pesticide registration forMagtoxin® Granules have been submitted toCanada, the United States and othercountries.

After the Horn Generator is activated, it auto-matically flushes the system with carbon diox-ide gas, fills the reaction chamber with waterand turns on the recirculation fan. Once theseoperations are completed, the granules may bemanually loaded into the fumigant reservoirinside the instrument. A switch is then acti-vated which automatically transfers the gran-ules to the reactor, and the injection of phos-phine into the structure is begun. The HornGenerator is designed to react the contents of

The set up of ECO2FUME™ cylinders for one of the phosphinetreatments.

11

one flask of granules in about seven minutes.The transfer lines and reaction chamber insidethe Horn Generator must be cleaned after theaddition of 21 flasks (one case of granules).A solution of formic acid is used to wash outthe magnesium carbonate. It takes about 30minutes to clean the Horn Generator andprepare it for subsequent additions of thegranules.

To reach the target concentration of 1000 ppmPH3, 24 flasks of Magtoxin® Granules wereused to produce the 9833 g (21.6 lb.) PH3.The Horn Generator was positioned about

10 m (30 ft.) from the manhole used to housegas sampling lines, test insects, thermocoupleleads and recirculation tubing used for injec-tion and recirculation of phosphine in thehold. The injection tubing was extended tothe bottom of the hold, a total length of about23 m (70 ft.).

The Horn Generator was turned on at 12:40p.m. on June 6, 1999. After a brief period tofill the reaction chamber with water and flushout the system with carbon dioxide, theaddition of granules began at 12:49 p.m.Shortly after granules where added to thereaction chamber, it became apparent that theHorn Generator was not performing up tospecifications. The low air flow alarm wentoff repeatedly, automatically stopping addi-tion of the granules to the reaction chamber.This problem persisted throughout the addi-tion period to the extent that injection ofphosphine took almost twice as long asexpected. Introduction of phosphine from 24flasks of granules into the hold was complet-ed at 6:20 p.m. on June 6.

It was subsequently learned that the ship wasunable to supply consistent water pressure,and that pressure surges in the water line tothe Horn Generator caused water to splashout of the reaction chamber into the pump,thereby retarding the air flow. The pressuredrop resulting from the greatly extendedlength of the injection line from the HornGenerator may have been a contributing fac-tor. A surge protector has been installed onthe water inlet line to the Horn Generator.Tests subsequent to the experiment showedthat lengthening the recirculating lines hadno effect on the air flow rate.Placing Degesch Magtoxin® Granules into the Horn Generator.

12

Results

Temperature, relative humidity and gasconcentrationsOver the three-day test, temperatures in theship holds varied between 33˚C and 15˚C(Figure 2), with an average temperature dur-ing the first day of fumigation of 23˚C. Vialtemperatures were similar to the ship bulkhead temperatures. Temperatures were slight-ly warmer at the top level compare with

lower levels (Table 2). Relative humidity var-ied between 62 and 17% (Figure 2). Both rel-ative humidity sensors gave similar read-ings, and did not seem to be affected by thephosphine.

The target gas concentrations were reached atall three levels after nine hours for methyl bro-mide (5400 ppm), 1.5 hours forECO2FUME™ (500 ppm phosphine) and 5.5hours for the Horn Generator (1000 ppmphosphine). Phosphine was detected in thebottom of the control hold, but it neverexceeded 10 ppm (Table 3, Figure 3).

Boundary line air monitoring was conductedthroughout the treatment period. Low levelphosphine gas readings were taken every sixhours. No detectable levels of phosphine(>0.01 PPM, limit of delectability) wererecorded at the boundary lines during the

Figure 2. The changes in temperature and relativehumidity during the ship hold fumigation.

Table 2. The temperatures of ship bulk heads and vials con-taining insects at three different levels in the holds contain-ing different treatments. This data set used temperaturestaken just before treatments were begun, 10:00 a.m. June 5,until 3:00 p.m. June 6.

Table 3. The concentration of fumigants in the ship holds.Measurements in gray underestimate true concentrationsdue to slight vacuum in holds caused by cooling. The tar-get concentrations of methyl bromide treatment was 5400ppm, for the ECO2FUME™ treatment was 500 ppm phos-phine and for the Horn Generator treatment it was 1000ppm phosphine

13

fumigations, including during the aeration.The recycling warehouse was approximately15 m (47 ft.) from the vessel and 20 m (64 ft.)from the top of the fumigated holds. No phos-phine was detected in the ship quarters. Theonly ship crew member onboard wore aDraeger PAC III at all times and phosphinewas never detected during the trial. Low lev-els of phosphine were detected in the tunnelsthat ran beside the holds and above the wingtanks. These tunnels were sealed to preventany further spread of the phosphine. Beforethe experiment commenced, repair crews hadmade a 1 m x 2 m (3 ft. x 6 ft.) hole in the sidewall of hold 3. This may have been responsi-ble for the leakage of phosphine into thetunnels.

Insect bioassaysAfter 32 hours, none of the adult insects sur-vived in any of the three fumigation treat-ments. In the control hold there was at least98% survival of adults for all species after 32hours (Table 4). After one week, none of theinsects from the fumigated holds had revived,

and the survival of insects removed from thecontrol hold after 32 hours was not less than92% for all species, except the lesser grainborer which had an average mortality of69±8% (mean±SEM) (Table 5). Insects fromthe bottom of the control hold had a lower sur-vival rate than those held higher up. This wasprobably due to the higher concentrations ofphosphine, which reached about 10 ppm, at thebottom level as compared with the negligible

Figure 3. The concentrations of fumigants in the shipholds. Measurements in gray underestimate true concen-trations due to slight vacuum in holds caused by cooling.

Table 4. Survival of adults in untreated hold immediatelyafter taken from ship hold. All adults in the treated holdswere dead after 32 hours.

Table 5. Survival of adults in untreated hold one weekafter taken from ship hold. None of the adults classed asdead immediately after being removed from the treatedholds had revived after one week.

14

concentrations at the higher levels (Table 3).There was a slight decrease in survivorship inthe untreated hold with the duration of expo-sure. The survival rate for the lesser grainborer adults was lower than the other testspecies.

Egg survival was estimated by the number ofadults emerging after 5 weeks (Table 6). Forthe red flour beetle, rice weevil and the lessergrain borer, 11 to 107 adults emerged fromeach vial held in the untreated hold. In the

treated holds, after 32 hours there were nomore than 5 adults emerging per vial. Thisdropped to no more than an average 0.4 adultsper vial after 48 hours into the treatment.There was no emergence from the treatedholds after 72 hours. These results are sum-marized in Table 7. The rusty grain beetle hadan average of only 0.1 to 0.3 adults from eachvial from the untreated hold, hence it wasimpossible to estimate their mortality due tofumigation.

Corrosion assaysCopper strips showed visible corrosion whenremoved from both phosphine fumigationtreatments. There was a linear increase in cor-rosion with time. More corrosion wasobserved at the higher phosphine treatment(1000 ppm) although it did not double theamount of corrosion observed at the lower

phosphine treatment (500 ppm) (Figure 4).These results are consistent with laboratorystudies (Brigham 1999). There was no signifi-cant difference between corrosion at the bot-tom or top level (two way ANOVA; p= 0.48,for level, p> 0.001 for duration) The phone

Table 6. The number of adults per vial that emerged after5 weeks at 30˚C. Twenty-five adults were held in vials for 3days with 20g of wheat to allow oviposition. Vials wereexposed to treatments in ship holds for 32, 48 and 72 hoursbefore the adults were shaken from wheat and the wheatwith eggs returned to the vial.

Table 7. The survival of eggs in treated ship hold as com-pared to eggs in untreated ship hold.

Figure 4. The change in weight (+SEM) of copper stripsin untreated holds with either 500 or 1000 ppm phosphine

15

jacks showed no visible signs of corrosion,non-conducting surface deposits or breakingof circuits due to corrosion. There was noincrease in the resistance across the treatedphone jacks. The 486 mother board placed inthe 1000 ppm hold showed visible deposits onthe brass spring connectors.The computer held in the 500 ppm hold for25.5 hours showed corrosion deposits on thesolder coated copper junctions and no longerfunctioned, however, the high temperaturesreached in the hold may also have contributedto the malfunction.

Recapture of methyl bromideEighty-one percent of the 114 kg (250 lb.) ofmethyl bromide released in the fumigationwas recaptured. The recapture system wasdesigned to capture 91 kg (200 lb.) of methylbromide and it captured 92 kg (203 lb.). Therecapturing period spanned approximately 6hours before the sieve was full, excluding the1.5 hours the unit was shut down during thethunderstorm.

16

Discussion

Each of the three treatments could be used tolimit the methyl bromide emissions to theatmosphere due to ship hold fumigations.These methods would cost more than the cur-rent methyl bromide treatments, and there aresome regulatory issues that would have to beaddressed before these methods could be usedin ship hold fumigations.

Recapture of methyl bromideThis method would have to be scaled up inorder to treat entire ocean-going vessels which have holding capacities ranging from 30 000to 100 000 m3 (1 000 000 to 3 500 000 ft3). Collectors or sieves can be built to capture160 kg (350 lb.) of methyl bromide and couldbe applied during methyl bromide fumigationsof containers used for quarantine purposes. Abusiness model developed by Cryo-LineSupplies Ltd. envisages 20 collectors at thePort of Vancouver. The cost of the collectorper usage would be $CAN 1750, assumingeach collector would be used twice a month.Each unit is expected to last ten years.

Cryo-Line Supplies Ltd. proposes the follow-ing scenario for the recapture of methyl bromide at ports.

1. Each port would have an established area,or recapture dock, with an evacuation system(either a single blower or several smallerblowers) where fumigations with methyl bro-mide would take place. This would mainly bedone for safety reasons, and to reduce costsfor the set-up blowers and piping.

2. Containers and ships would be brought tothe recapture dock. The piping placed in thechamber, container, or ship would be connect-ed to the stationary network piping via theappropriate number hoses to remove themethyl bromide in the required amount oftime.

3. At the end of the fumigation, the methylbromide would be pulled through the pipingand blown through the collectors where itwould be trapped.

4. Once filled, the collectors would beexchanged for empty units. The saturated col-lectors would be transported back to a centralplant for methyl bromide reclamation, conden-sation and re-packing into reclaim cylinders.

5. The methyl bromide would be reprocessedto a standard, and returned to the fumigatorfor reuse.

There are several advantages to the recaptureof methyl bromide:

• Less methyl bromide would be vented tothe atmosphere;

• Less of a hazard to workers when openingthe fumigated hold or container;

• Recaptured methyl bromide would be avail-able for reuse;

• Clearing ship holds of methyl bromide maybe quicker;

• Unlike the other treatments used in thistrial, recapture requires no registration fromHealth Canada;

• Very little change from the present fumiga-tion method is required, other than someadditional equipment to be added to theship hold, container or chamber before seal-ing.

There are some hurdles to overcome beforethis method could be used:

• Approvals would have to be gained fromthe Ministry of Transportation for themovement of the captured methyl bromide.

• Labeling of the reclaimed methyl bromide.• Ownership of the reclaimed methyl

bromide.• Clarification if reclaimed methyl bromide

falls outside quota allocations.

17

One way to reduce the amount of methyl bro-mide to be recaptured and hence the size ofthe collector required, would be to inflatelarge balloons inside the hold to reduce thedead space that must be fumigated. Theseballoons would have to be impermeable tomethyl bromide, so that the gas is not dilutedbelow the effective dose required in the shiphold, and the gas could be safely and quicklyrecaptured after the fumigation. This tech-nique has been used in churches in Germanyto reduce the space by 80%, before fumigatingwith sulfuryl fluoride (Binker 1993).

ECO2 FUME™A ship hold of 6000 m3 would require 10cylinders of ECO2FUME™ at $CAN150/cylinder. The major additional cost com-pared to a methyl bromide fumigation wouldbe the longer durations needed at low temper-ature. The demurrage charges for ships atdock are approximately $CAN 10 000 perday. There is also the additional cost of leav-ing the ship idle.

The advantage of using ECO2FUME™ is thatno methyl bromide would be released into the atmosphere, and it would be faster thanfumigating with aluminum phosphide or mag-nesium phosphide formulations.

There are two main obstacles preventing theuse of ECO2FUME™ to control insects in empty ship holds. Longer durations are need-ed for phosphine to work at low temperaturesthan methyl bromide. The temperatures dur-ing this trial were warm, with highs above30˚C. However, ships often must be fumigat-ed in cooler weather. Phosphine efficacy isreduced more by low temperatures then ismethyl bromide (Bond 1984). Phillips (1998)showed that at 200 ppm phosphine generatedusing ECO2FUME™ after 24 hours at 5˚Cgave more than 80% mortality of stored-prod-uct adult beetles but only 15 to 80% mortalityfor the eggs. A 72-hour exposure was neededto obtain from 75 to 100% mortality of eggs.The higher concentrations used in this trial

would cause some increased mortality even atthese low temperatures. However, with phos-phine, higher concentrations cannot entirelycompensate for shorter durations, i.e., dou-bling the concentration will not half the timeneeded for control. Ships are heated for paint-ing, and this technique could be used to pre-heat ships before a phosphine fumigation, toincrease the effectiveness of the treatment.The second obstacle is that ECO2FUME™ isnot registered in Canada, although CytecCanada Ltd. has shown interest in registeringthis product in Canada.

Horn Generator / Magtoxin® GranulesSystemAs with ECO2FUME™, low temperaturefumigations would require more time thanfumigations done with methyl bromide. Thedisposal of the magnesium carbonate also hasto be addressed. Applications for registrationof Magtoxin® Granules intended for use withthe Horn Generator have been submitted inCanada, with the support of DEGESCHAmerica, Inc. The cost of a fumigation usingthe Horn Generator / Magtoxin® GranulesSystem is not available at this time.

Potential use in other applicationsThese techniques could be used in other situa-tions where methyl bromide is used to controlinsects and pathogens. Containers hold every-thing from manufactured goods to fruits.Some may be fumigated with methyl bromideat export or at import for quarantine or otherreasons. Cryo-Line Supplies Ltd. has alreadydemonstrated in the port of Savannah, Georgiathat methyl bromide can be recaptured fromcontainers, and they have shown in this trialthat it can also be readily recaptured fromlarge volume spaces.

Both phosphine generating methods could beused in conjunction with heat and carbondioxide to fumigate food processing plants(Mueller 1993, Marcotte 1996). These fumi-gation techniques would be more accuratethan the current method which uses aluminum

18

or magnesium phosphide. It would also alle-viate the need to re-enter the fumigated struc-ture to add or remove fumigant. Another ben-efit of the combination method is it uses lowerphosphine concentrations (100 ppm ) thanwere used in this study, thereby minimizingcorrosion.

The Horn Generator has been used commer-cially in South America for several years.During this period a wide variety of structureshave been fumigated. A number of tests havebeen conducted in North America. Warehouses(single and multi-floor), chambers, tarpaulinsand large-grain silos have been successfullytreated.

Other alternatives to empty ship hold fumiga-tions with methyl bromide

A thorough cleaning of the holds after unload-ing grain or any other cargo is an excellent andpreferred method to prevent insects from find-ing food and harborage in the empty shipholds. Modern ship design has greatly reducedthe residues of grain left after unloading, mak-ing good sanitation easier. This results infewer insects left in the hold that could infestthe next cargo of grain. In 1948 / 1949, of the517 ships inspected, 8% had to be fumigatedbecause of insects in the empty holds (Monro1951). Today, about 2% of the inspected shipsare fumigated (Table 1).

In the USA and Australia, very few emptygrain ships are fumigated with methyl bromide.In the USA, if an infestation is found, the holdis cleaned and sprayed with residual insecti-cides such as cyfluthrin or malathion. There isalso less of a concern with insects in the emptyship holds in the USA because grain is oftenfumigated in transit with phosphine, or isalready protected with a residual insecticide onthe grain. (L. Zettler, personal communica-tion). In Australia, ships are steam cleaned atsea. If a ship still has insects in its holds,

then the ship is turned away. (J. Banks, per-sonal communication). Cleaning is also themost frequent method employed in Canada. InFrance, methyl bromide has not been used tofumigate ship holds since 1950. Extensiveinsect infestations in ship holds are controlledwith dichorvos. For limited infestations, thegrain is treated with dichorvos at loading orwith phosphine after loading (P. Ducom, per-sonal communication).

It is rare that Canadian grain is treated with aresidual insecticide, such as malathion ordiatomaceous earth, because of Canada’s coldwinters and because phosphine is used to con-trol infestations at the farm and primary eleva-tors. As grain treated at the farm is dilutedwith untreated grain, export grain has almostno residual insecticide on the grain. Hence,Canadian grain is susceptible to infestation ifinsects are present in ship holds at loading.Customers sometimes request that grain betreated with malathion as it is loaded onto theships, however, most Canadian customers donot want the grain treated with residual insecti-cides. Fumigation of grain with phosphine inships is permitted in Canada as it does notleave residues on the grain. This type of treat-ment would be similar in cost to a methyl bro-mide fumigation of empty ships, and wouldalso kill any insects that had previously been inthe ship. The Canada Grain Act, however,does not allow loading grain into infested ves-sels. Another option would be to turn away theapproximately 25 ships annually that wouldrequire a methyl bromide treatment, as is donein Australia.

Finally, sulfuryl fluoride (Vikane) is registeredfor ship hold fumigations in the USA; however,it is rarely used in ship holds and is mainlyused against termites. Sulfuryl fluoride is notvery effective against eggs, and requires longerexposures than methyl bromide against otherlife stages of insects (Bond 1984). It is notregistered as a pesticide in Canada.

19

References

Anonymous 1998. United Nations Environment Programme (UNEP) Methyl Bromide Technical Options Committee (MBTOC). 1998 Assessment of the Alternatives to Methyl Bromide.United Nations Environment Programme, Nairobi: 374 pp

Banks, HJ. 1984. Modified atmospheres - testing of storage structures for gas tightness, pp533-543. In Champ, B.R. and Highley, E. [Eds.] Proceedings of the Australian Development Assistance Course on Preservation of Stored Cereals.Vol. 2 (CSIRO) Division of Entomology, Canberra.

Binker G. 1993. New concepts for environment protection and new developments in the fumigation of cultural property. Conference Proceedings: Fumigation As a Means ofWood Pest Control pp. 90-99.

Bond, E. 1984. Manual of fumigation for insect control.FAO Plant Production and Protection Paper 54, 430 pp

Brigham, R. 1999. Corrosive effects of phosphine, carbon dioxide, heat and humidity onelectronic equipment: phase II. Report prepared for the Environment Bureau, Agriculture and Agri-Food Canada. Available on the world wide web athttp://www.agr.ca/policy/environment

Monro, HAU. 1951. Insect pests in cargo ships. Canadian Department of Agriculture Publication 855.

Mueller, DK. 1993. Low concentration phosphine fumigation method US patent 5,403,597

Marcotte, M., Demianyk, C., Van Ryckeghem, A., Mueller, J. and McCarthy B. 1996. Heat,phosphine and CO2: Collaborative Experimental Structural Fumigation. Report prepared for the Environment Bureau, Agriculture and Agri-Food Canada. Available on the world wide web at http://www.agr.ca/policy/environment

Phillps TW. 1998. Cylinder-based phosphine for control of postharvest insect pests. Annual International Research Conference on Methyl Bromide Alternatives and Emissions Reductions 86-89. available on the world wide web at http://www.epa.gov/docs/ozone/mbr/1998airc/086phillips.pdf

Pearson, D. 1995. Report on the explosive properties of phosphine in the presence of carbon dioxide and air. (Report prepared for BOC Gases, by WorkCover Authority, Londonderry Occupational Safety Centre) 19 pp.

20

Appendix A: Experimental Labels:

21

RESTRICTED USE PESTICIDEDUE TO ACUTE INHALATION TOXICITY OF HIGHLYTOXIC HYDROGEN PHOSPHIDE (PHOSPHIDE PH3) GASFor retail sale to and use only by provincially licenced applicators for those uses covered by the applicator’s certifica-tion or persons trained in accordance with the Applicators Manual working under the direct supervision and in thephysical presence of the provincally licenced applicator. Physical presence means on site or on the premises. Read andfollow the label and the Applicators Manual which contains complete instructions for the safe use of this pesticide.

DEGESCH MAGTOXIN®

DEGESCH MAGTOXIN® GRANULES

FOR CONTROL OF PESTS IN STORED GRAIN, PROCESSED FOODS, FEEDSAND NON-FOOD COMMODITIES INCLUDING TOBACCO

Active Ingredients: Magnesium Phosphide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96%Inert Ingredients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4%

KEEP OUT OF REACH OF CHILDRENDANGER POISON

P.C.P.#:

(TO THE USER: If you cannot read English, do not use this product until the label has been fully explained to you).

STATEMENT OF PRACTICAL TREATMENTSymptoms of overexposure are headache, dizziness, nausea, difficult breathing, vomiting and diarrhea. In all cases ofoverexposure get medical attention immediately. Take victim to a doctor or emergency treatment facility.

If the gas or dust from magnesium phosphide is inhaled:Get exposed person to fresh air. Keep warm and make sure person can breathe freely. If breathing has stopped, giveartificial respiration by mouth-to-mouth or other means of resuscitation. Do not give anything by mouth to an uncon-scious person.

If magnesium phosphide GRANULES or powder are swallowed:Drink or administer one or two glasses of water and induce vomiting by touching back of throat with finger, or if avail-able, syrup of ipecac. Do not give anything by mouth if victim is unconscious or not alert.

If dust from granules of magnesium phosphide get on skin or clothing:Brush or shake material off clothes and shoes in a well-ventilated area. Allow clothes to aerate in a ventilated areaprior to laundering. Do not leave contaminated clothing in occupied and/or confined areas such as automobiles, vans,motel rooms, etc. Wash contaminated skin thoroughly with soap and water.

If dust from granules get in eyes:Flush with plenty of water. Get medical attention.

NET CONTENTS:850g of GRANULES

Manufactured By: Distributed By: Canadian Agent:DEGESCH DE CHILE LTDA. DEGESCH AMERICA INC. GARDEX CHEMICALSLTD.Camino Antiguo a Valparaaiso #1321 P.O. Box 116 7 Meridian RoadPadre Hurtado Weyers Dave, VA Etobicoke, OntarioSantiago Chile 24486 U.S.A. M9W 5B4 Canada

Tel: 540-234-9281 Tel: 416-675-1638

22

DIRECTION FOR USEThis product can only be used/applied within the Horn Generator.It is a violation of the Pest Control Products Act to use this product in a manner inconsistent with its labeling. Thisproduct is accompanied by an approved Applicators Manual. Read and understand the entire labeling. All parts of thelabeling are equally important for safe and effective use of this product. Call DEGESCH, America Inc. or GardexChemicals Ltd. if you have any questions or do not understand any part of this labeling.Refer to the Applicators Manual for more detailed precautions, recommendations and directions for use.

STORAGE INSTRUCTIONS1. Store DEGESCH MAGTOXIN® GRANULES in a dry, well-ventilated area away from heat, under lock and key.

Post as a pesticide storage area. Do not contaminate water, food or feed by storing pesticides in the same areasused to store these commodities.

2. Do not store in buildings where humans or domestic animals reside. Keep out of reach of children.3. DEGESCH MAGTOXIN® GRANULES are supplied in gas-tight, re-sealable aluminum flasks.

4. The shelf life of MAGTOXIN® GRANULES is virtually unlimited as long as the containers are tightly sealed.

DISPOSAL INSTRUCTIONSDo not contaminate water, food or feed by storage or disposal.Unreacted or partially reacted MAGTOXIN® GRANULES are acutely hazardous. Improper disposal of excess pesti-cide is a violation of the Pest Control Products Act. If these wastes cannot be disposed of by use according to the labelinstructions, contact the manufacturer or distributor for guidance. For specific instruction, see Spill and LeakProcedures in the Applicatorís Manual. Some local and provincial waste disposal regulations may vary from the fol-lowing recommendations. Disposal procedures should be reviewed with appropriate authorities to ensure compliancewith local and provincial regulations. Dispose of containers in a sanitary landfill or by other procedures approved byprovincial and local authorities. If properly exposed during the fumigation period, spent MAGTOXIN® GRANULESwill contain virtually no unreacted magnesium phosphide. This will be a non-hazardous waste. However, incompletelyexposed MAGTOXIN® GRANULES will require special care for disposal.

SPILL AND LEAK PROCEDURESGeneral Precautions and DirectionsA spill, other than incidental to application or normal handling, may produce high levels of gas and, therefore, attend-ing personnel must wear SCBA or its equivalent when the concentration of hydrogen phosphide gas is unknown. OtherNIOSH/MSHA approved respiratory protection may be worn if the concentration is known or found to be less than 15ppm. Do not use water at any time to clean up a spill of DEGESCH MAGTOXIN® GRANULES. Water in contactwith unreacted metal phosphides will greatly accelerate the production of hydrogen phosphide gas which could result ina toxic and/or fire hazard. Wear gloves of cotton or other breathable material when handling metal phospides.Return all intact aluminum flasks of MAGTOXIN® GRANULES to original cases or other packaging which has beensuitably constructed and marked according to T.D.G.A. regulations. Notify consignee and shipper of damaged cases.If the flasks have been punctured or damaged so as to leak, they must be temporarily repaired with aluminum tape.Transport the damaged flasks, thus sealed, to an area suitable for pesticide storage for inspection. Caution: The punc-tured flasks may flash upon opening at some later time. Refer to the Applicatorís Manual for more detailed Spill andLeak procedures. Further instructions and recommendations may be obtained, if required, from DEGESCH America,Inc. or Gardex Chemicals Ltd.

THIS PRODUCT IS ACCOMPANIED BY AN APPROVED LABEL AND APPLICATORS MANUAL. READ ANDUNDERSTAND THE ENTIRE LABELING. ALL PARTS OF THE LABELING ARE EQUALLY IMPORTANT FORSAFE AND EFFECTIVE USE OF THIS PRODUCT. CALL DEGESCH AMERICA, INC. OR GARDEX CHEMI-CALS LTD. IF YOU HAVE ANY QUESTIONS OR DO NOT UNDERSTAND ANY PART OF THIS LABELING.

REFER TO THE APPLICATORS MANUAL FOR DETAILED PRECAUTIONS, RECOMMENDATIONS ANDDIRECTIONS FOR USE.

Warranty: Seller warrants that the product conforms to its chemical description and when used according to labeldirections under normal conditions of use, it is reasonably fit for the purposes stated on the label. Seller makes no otherwarranty either express or implied, and buyer assumes all risk should the product be used contrary to label instructions.

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PRECAUTIONARY STATEMENTS

HAZARDS TO HUMANS AND DOMESTIC ANIMALSDANGER: Magnesium phosphide from DEGESCH MAGTOXIN® GRANULES or dust may be fatal if swallowed.Do not get in eyes, on skin or on clothing. Do not eat, drink or smoke while handling magnesium phosphide fumi-gants. If a sealed container is opened, or if the material comes into contact with moisture, water or acids, these prod-ucts will release hydrogen phosphide (phosphine, PH3 which is an extremely toxic gas. If a garlic odour is detected,refer to the Industrial Hygiene Monitoring Section of the Applicators Manual for appropriate monitoring procedures.Pure hydrogen phosphide gas is odourless; the garlic odour is due to a contaminant. Since the odour of hydrogen phos-phide may not be detected under some circumstances, the absence of a garlic odour does not mean that dangerous lev-els of hydrogen phosphide gas are absent. Observe proper re-entry procedures specified elsewhere in the labeling toprevent overexposure.

NOTE TO PHYSICIANMagnesium phosphide GRANULES, or dust re-acts with moisture from the air, acids and many other liquids to releasehydrogen phosphide (phosphine, PH3) gas. Mild exposure by inhalation causes malaise (indefinite feeling of sickness),ringing in the ears, fatigue, nausea and pressure in the chest which is relieved by removal to fresh air. Moderate poi-soning causes weakness, vomiting, pain just above the stomach, chest pain, diarrhea and dyspnea (difficulty in breath-ing). Symptoms of severe poisoning may occur within a few hours to several days resulting in pulmonary edema (fluidin lungs) and may lead to dizziness, cyanosis (blue or purple skin), unconsciousness, and death.

In sufficient quantity, phosphine affects the liver, kidneys, lungs, nervous system and circulatory system. Inhalation cancause lung edema (fluid in lungs) and hyperemia (excess of blood in a body part), small perivascular brain hemor-rhages and brain edema (fluid in brain). Ingestion can cause lung and brain symptoms but damage to the viscera (bodycavity organs) are more common. Phosphine poisoning may result in (1) pulmonary edema, (2) liver elevated serumGOT, LDH and alkaline phosphatase, reduced prothrombin, hemorrhage and jaundice (yellow skin colour) and (3) kid-ney hematuria (blood in urine) and anuria (abnormal or lack of urination). Pathology is characteristic of hypoxia (oxy-gen deficiency in body tissue). Frequent exposure to concentrations above permissable levels over a period of days orweeks may cause poisoning. Treatment is symptomatic.

PHYSICAL AND CHEMICAL HAZARDSMagnesium phosphide GRANULES and partially spent dust will release hydrogen phosphide if exposed to moisturefrom the air or if it comes into contact with water, acids and many other liquids. Magnesium phosphide is considerablyreactive and will liberate gas rapidly. This is particularly ture in the presence of liquid water and at higher tempera-tures. Since hydrogen phosphide may ignite spontaneously at levels above its lower flammable limit of 1.8% v/v, it isimportant not to exceed this concentration. Magnesium phosphide fumigants should not be stacked or piled up or con-tacted with liquid water. This may cause a temperature increase, increase the rate of gas production and confine the gasso the ignition could occur.

It is preferable to open containers of magnesium phosphide products in open air as under certain conditions, they mayflash upon opening. Containers may also be opened near a fan or other appropriate ventilation which will rapidlyexhaust contaminated air. When opening flasks of MAGTOXIN® GRANULES, point the flask away from the faceand body and twist the cap off. Although the chances for a flash are very remote never open these containers in a flam-mable atmosphere. These precautions will also reduce the fumigatorís exposure to hydrogen phosphide.Pure phosphine (hydrogen phosphide) gas is practically insoluble in water, fats, oils, and is stable at normal fumigationtemperatures. However, it may react with certain metals and cause corrosion, especially at higher temperatures and rel-ative humidities. Metals such as copper, brass and other copper alloys, and precious metals such as gold and silver aresusceptible to corrosion by phosphine. Thus, small electric motors, smoke detectors, brass sprinklers heads, batteriesand battery charges, fork lifts, temperature monitoring systems, switching gears, communication devices, computers,calculators and other electrical equipment should be protected or removed before fumigation. Hydrogen phosphide willalso react with certain metallic salts and, therefore, sensitive items such as photographic film, some inorganic pigments,etc. should not be exposed.

24

Appendix B: Collaborators and Contact List:

Pierre BeauchampPest Management Regulatory Agency1033 Health Canada2250 Riverside Dr.Ottawa, ON K1A 0K9, CanadaTelephone: 613-736-3756, Fax: 613-990-0605Email: pierre_beauchamp@hc-sc.gc.ca

Robert J. BrighamConsultant to the Environmental BureauAgriculture and Agri-Food Canada930 Carling Ave, Rm 367 Ottawa, ON K1A 0C5, Canada

Denis BureauAdalia Preventive Services Ltd.8685 Lafrenaie StSt-Leonard, PQ H1P 2B6, CanadaTelephone: 514-852-9800, Fax: 514-852-9809Email: adalia@videotron.ca

Roger CavasinCytec Canada Inc.P.O. Box 240Niagara Falls, ON L2E 6T4, CanadaTelephone: 905-374-5828, Fax: 905-374-5939Email: roger_cavasin@we.cytec.com

Geoff M.CuttenMinistry of the Environment40 St. Clair Avenue West, 7th floorToronto, ON M4V 1M2Telephone: 416-327-5174, Fax: 416-327-2936Email: cutteng@ene.gov.on.ca

Paul FieldsAgriculture and Agri-Food CanadaCereal Research Centre195 Dafoe Rd.Winnipeg, MB R3T 2M9, CanadaTelephone: 204-983-1468, Fax: 204-983-4604Email: pfields@em.agr.ca

25

Nancy KummenCanadian Food Inspection AgencySuite 350 601 West CordovaVancouver, BC V6B 1G1, CanadaTelephone: 604-666-5847, Fax: 604-666-1550Email: kummenn@em.agr.ca

Sheila JonesAgriculture and Agri-Food CanadaPolicy Branch, Environment Bureau930 Carling AveOttawa, ON K1A 0C5, CanadaTelephone: 613-759-7300, Fax: 613-759-7238Email: jonessh@em.agr.ca

Dorothy LaidlawCanadian Food Inspection AgencyPlant Products DirectoratePlant Health and Production DivisionGrains and Field Crops Section59 Camelot DriveNepean, ON K1A 0Y9Telephone: 613-225-2342 (ext 4338), Fax: 613-228-6626Email: dlaidlaw@em.agr.ca

Brett MacKillopAbell Pest Control Ltd.246 Attwell Dr.Etobicoke, ON M9W 5B4, CanadaTelephone: 416-675-3305 (ext 318) Fax: 416-675-6727Email: bmackillop@abellgroup.com

Bernie McCarthyPCO Services Inc.5840 Fallborne StMississauga, ON L5R 3L8, CanadaTelephone: 905-502-9700, Fax: 905-502-9510Email: bmmccart@scj.com

John McIssacCryo-Line Supplies Ltd.3100 Ridgeway Dr., Unit 28Mississauga, ON L5L 5M5, CanadaTelephone: 905-608-2919, Fax: 905-608-2926Email: cryoline@cryoline.on.ca

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Mike McLeanDegesch America Inc.P.O. 451036Houston, TX 77245, USATelephone: 713-433-4777, Fax: 713-433-0877Email: mmclean@degeschamerica.com

Michel MaheuMahueu and Maheu Inc.710 Bouvier Ave, Suite 195Quebec, PQ G2J 1C2, CanadaTelephone: 418-623-8000, Fax: 418-623-5584Email: mmaheu@maheu-maheu.com

Mark MatthewsDegesch America Inc.P.O. 116Weyers Cave, VA 24486, USATelephone: 804-231-1000, Fax: 804-231-1047Email: degesch@erols.com

Dave MuellerFumigation Service and Supply Inc.16950 Westfield Park Rd.Westfield, IN 46074-9374, USATelephone: 317-896-9300, Fax: 317-867-5757Email: InsectsLtd@aol.com

Stephen MurchUpper Lake Group Inc.49 Jackes Ave,Toronto, ON M4T 1E2, CanadaTelephone: 416-920-7610, Fax: 416-920-5785

Don SchaheenDegesch America Inc.P.O. 116Weyers Cave, VA 24486, USATelephone: 540-234-9281, Fax: 540-234-8225

Martin St-PierreMaheu & Maheu Inc.1300 Gay-Lussac #100Boucherville, QC J4B 7G4, CanadaTelephone: 450-449-3504, Fax: 450-449-5776Email: mst-pierre@maheu-maheu.com

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Blaine TimlickCanadian Grain Commission303 Main StWinnipeg, MB R3C 3G8, CanadaTelephone: 204-983-2788, Fax: 204-983-7550Email: btimlick@cgc.ca

Alan Van Ryckeghem.Fumigation Service and Supply Inc.Westfield Park Rd.Westfield, IN 46074-9374, USATelephone: 317-896-9300, Fax: 317-867-5757Email: InsectsLtd@aol.com

Murray WeightmanCryo-Line Supplies Ltd.3100 Ridgeway Dr., Unit 28Mississauga, ON L5L 5M5, CanadaTelephone: 905-608-2919, Fax: 905-608-2926Email: cryoline@cryoline.on.ca

Noel WhiteAgriculture and Agri-Food CanadaCereal Research Centre195 Dafoe Rd.Winnipeg, MB R3T 2M9, CanadaTelephone: 204-983-1452, Fax: 204-983-4604Email: nwhite@em.agr.ca

Larry ZettlerHorticultural Crops Research LaboratoryUnited States Department of Agriculture, Agriculture Research Service2021 S Peach AveFresno, CA 93727, USATelephone: 559-453-3023, Fax: 559-453-3088email: lzettler@qnis.net

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