MB Alternatives in dried fig sector1 DO VACUUM CHAMBERS HAVE A FUTURE AFTER THE LOSS OF METHYL BROMIDE? Patrick DUCOM National Stored Products Laboratory.

MB Alternatives in dried fig sector 1

DO VACUUM CHAMBERS HAVE A FUTURE AFTER THE LOSS OF METHYL

BROMIDE?”

Patrick DUCOM

National Stored Products Laboratory

France

MB Alternatives in dried fig sector 2

VACUUM CHAMBERS IN TURKEY AND ELSEWHERE

There are at least two vacuum chambers for figs, surely more, in turkey.

E.U., mainly France and Italy (dried fruits, seeds, rice), Algeria Tunisia for soft-fresh datesCalifornia (bactericide for walnut meat)

MB Alternatives in dried fig sector 3

They are used with MeBr which allows a very quick disinfestation, all stages, at any temperature. 2 to 3 runs a day are possible.

It is a part of an industrial process with no storage and no re-infestation.

That allows a quick logistic in a continuous process.

Without MeBr, what to do?

MB Alternatives in dried fig sector 4

Companies are still using processing with vacuum and are not aware of MeBr ban in Dec.

One case of CU was given for “vacuum” reasons: legume seeds processing

All others are hoping in a new fumigant for January!!!!

MB Alternatives in dried fig sector 5

SHORT HISTORY

Vacuum chambers

have been using long

ago, mainly for non penetrating fumigants like HCN, EtOx, EtOx+ CO2, CS2,…

In 1934, LEPIGRE was already improving what he called this « old » technique….

MB Alternatives in dried fig sector 6

Gas penetration was the target and the practice used three ways

Sustained-vacuum fumigation

Vacuum fumigation with simultaneous admission of air and fumigant

Vacuum fumigation with atmospheric pressure restored after a period

MB Alternatives in dried fig sector 7

Research in the 40’s - 50’s was focused on factors improving penetration to find the best one.

The diffusion law says gas diffuses better under vacuum and studies with CTP measurements show the sustained vacuum is the best way. But sorption is greater in this circumstances…..

MB Alternatives in dried fig sector 8

Finally, practice showed that time could be greatly reduced:

Typic : 80g/m3 – 4h.

Since these years, vacuum fumigation is running with MeBr, with success, mainly for products like compressed dried fruits, tobacco leafs or for quarantine.

MB Alternatives in dried fig sector 9

One question was never really answered: What is the intrinsic action of vacuum on the toxicity for insects?

It was studied case by case, for instance , for diapausing larvae of Codling moth, vacuum is two times more effective in terms of CTP than with NAP.

MB Alternatives in dried fig sector 10

WHAT TO DO WITH THE VACUUM CHAMBERS WHEN MEBR WILL

DISAPPEAR ?

To destroy them and work at NAP with toxic gas

To use for anoxia or insect emigration

To keep for new gases

MB Alternatives in dried fig sector 11

Conditions for a Fumigant Candidate for vacuum

1 - To be a fumigant, i.e. a toxic gas

2 - to more effective under vacuum than at NAP, allowing a quick logistic

3 - Registration is somewhere already obtained

4 - MRL’s are pending under codex alimentarius process and will be soon accepted in all the buyer countries

MB Alternatives in dried fig sector 12

fumigants for vacuum

Few candidates, but promising in the next 10 years:

Few private companies are interested, governmental bodies take patents.

Sulfuryl fluoride : SO2F2

Propylen oxide : PPO

Carbonyl sulfide : COS

Methyl iodide : CH3I

MB Alternatives in dried fig sector 13

To keep for new gases

In the short term, only one fumigant could replace MeBr: Sulfuryl fluoride, SO2F2

Reasons: There is a pesticide company who supports it (DowAgroscience)

Resarch and regulation are on the way

Problem: to convince Dow to sell SO2F2

MB Alternatives in dried fig sector 14

SO2F2 properties

Molecular weight: 102.07

Boiling point: - 55.2°C

Gas Caracteristics: colourless, Odourless.

Specific weight: 4.2 g/l

Relative density (air=1): 3.5[1]

Diffusion (perméation): very good

Non flammable

Water solubility 0.75g/l at 25°C

Non corrosive for metals

Xn

[1].

MB Alternatives in dried fig sector 15

EFFICAY AT NAP

Very effective on active insects life stages even pupae.

The corresponding CTP’s are of the same order than those necessary for MeBr : 200- 300 at 15 - 20° C

Typical: 15 g/m3 – 24h at 15-20°C.

MB Alternatives in dried fig sector 16

EFFICAY UNDER VACUUM

Some studies have been carried out: Zettler and Leesch,

As with MeBr, a factor 2 exists on all stages except eggs

There are differences between species

Süss in Italie began commercial test under vacuum for dried fruits.

MB Alternatives in dried fig sector 17

EFFICAY UNDER VACUUM

In France , we have been working for 4 years.

Results are promising, even for difficult situation.

We confirm that CTP is divided by half.

The problem seems coming from Carpophilus spp which are more tolerant than Plodia.

Experiments are running at 15, 20 and 25°C with eggs

Of 1, 2 , 3 and 4 day old (depends temperature), exposure time 4h.

MB Alternatives in dried fig sector 18

EFFICAY UNDER VACUUM

Carpophilus eggs

MB Alternatives in dried fig sector 19

EFFICAY UNDER VACUUM

SO2F2 works better with CO2

MB Alternatives in dried fig sector 20

Highest tried CTP

% Mortality

SO2F2, NAP 212 52

SO2F2, NAP + CO2 20%

220 63

SO2F2, VAC  280 97

SO2F2 VAC  + CO2 20%

235 98

SO2F2 works better with CO2 :Efficacy on

diapausing pupae of Leucoptera scitella Z (leaf miner)

MB Alternatives in dried fig sector 21

SO2F2 RESIDUES

Dow Agrosciences is in the process to have residues values in USA and are beginning to apply for Codex

MB Alternatives in dried fig sector 22

In or On Raw Commodity:

In or On Raw Commodity: F-

(USA)

In or On Raw Commodity:

SO2 F2 (USA)

Figs 5 0.05

Raisins 30 0.004

wallnuts 12 2

RESIDUES :Dow is in the process to have residues values in USA (table) and are beginning to apply for Codex Proposed (USA)

MB Alternatives in dried fig sector 23

FOR A FUTURE

For those who have vacuum chambers and the corresponding logistic, the economical risk is too high

to change all the system now.There are hopes to have alternatives adapted to these chambers, BUT, resarch is needed to accelerate the

implementation of the new gases: Research on efficacy

, Setting up international (residues) and national (registration) regulations.

MB Alternatives in dried fig sector 24

Studies to be carried outEfficacyRelationship between Species – stages - Dose - time – temperatureThe stages to be study: eggs.ResiduesDow is in the process to present it’s data to the codexPractical residues in the future turkish processRegistration in the country

Practical conditions for implementation in dried fruit industry

MB Alternatives in dried fig sector 25

Methyl iodide : CH3I (MeI)

The fumigant the closest of MeBr.First trials under vacuum are promising.

Toxicological data to be provided present a very big investment.

Long way!!!!!!!!

MB Alternatives in dried fig sector 26

PROPYLEN OXIDE (PPO)

Only registered in US for sterilization of packaged foods of Beverages, herbs and spices.Izikberand al, Zettler and al.found that PPO was insecticide but at high dosage and long exposure time if Temperature is below 30°C

?????

MB Alternatives in dried fig sector 27

CARBONYL SULFIDE (COS)

In the light of some preliminary tests, No promising under vacuum

(less effective, gives sulphur odour)

?????

MB Alternatives in dried fig sector 28

Destroy and work at Normal Atmospheric Pressure

Phosphine

To make the same job than with MeBr under VAC at 20°C, time is 5 days, the volume (V) of the new chamber must :

V = Vvac x MeBr runs per day x 5 days (duration)

Example, 2 runs, Vvac= 60 m3 V= 600 m3

Duration= 5 days + 1day handling (load/unload)

Two chambers are necessary to have figs every day.

If temperature is 15°C, 7 days V= 840 m3

MB Alternatives in dried fig sector 29

Destroy and work at Normal Atmospheric Pressure

SO2F2

To make the same job than with MeBr under VAC at 20°C, time is 1 days, the volume (V) of the new chamber must :

V = Vvac x MeBr runs per day x 1 days (duration)

Example, 2 runs, Vvac= 60 m3 V= 120 m3

Duration= 1 days + 1day handling (load/unload)

Two chambers are necessary to have figs every day.

If temperature is 15°C, 2 days V= 240 m3