Dear Forum Members.
Worldwide, the most commonly used fumigant to rid shipping containers of pests is methyl bromide. It is highly efficient at doing this but it is being phased out, worldwide, because it is an ozone layer depleter. Methyl iodide (MeI) is being considered as a substitute fumigation gas. It is equally efficient but has a much shorter atmospheric lifetime (and negligible ozone depletion potential) but is much less volatile. It is proposed to use it in combination with heat treatment where hot air (~45 degrees C) containing about 25g of methyl iodide/cubic m is circulated through the container in a closed system.
It is becoming less acceptable to discharge such a toxic material as MeI to the air, untreated, and I am looking for some way of adding a reagent to the circulating MeI to immobilise it/convert it to a non-toxic material inside the container, or discharge the MeI/hot air through an external reactor to do similar. A candidate for this is dimethyl sulphoxide which reacts with MeI to form a non-volatile sulfoxonium salt (CH3)3 SOI. Does anybody know if this would be a practical reaction to perform, in the gas phase, within the container, if DMSO was titrated into the circulating hot gas, as an aerosol, at the end of the decontamination time? Is the reaction time under these conditions sufficiently fast?
Is there another (cheap, readily available, low toxicity, volatile as an aerosol @ ~40 - 45 degrees C) compound that would do a better job under these conditions than DMSO.
I would greatly appreciate your thoughts and ideas,