DO VACUUM CHAMBERS HAVE A FUTURE AFTER THE LOSS OF METHYL BROMIDE?”

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 dates California (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. 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. 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 out Efficacy Relationship between Species – stages - Dose - time – temperature The stages to be study: eggs. Residues Dow is in the process to present it’s data to the codex Practical residues in the future turkish process Registration 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 MB Alternatives in dried fig sector