Ammonium Nitrate Chemistry

Methyl Bromide Leaves Residents Fuming

The Montreal Protocol on Substances that Deplete the Ozone Layer has proven to be a resounding environmental success, halting and then reversing the depletion of stratospheric ozone caused by man-made halogenated compounds.  Although global efforts initially focused on long-lived chlorofluorocarbons (CFCs), as their atmospheric levels have begun to decline it is emerging that "short-lived" ozone depleting substances with atmospheric lifetimes of months to years are playing an increasingly significant role, and they are also proving more of a challenge to eradicate.

The atmospheric chemistry of short lived ozone depleting substances is an area of research I'm currently working on, so I was intrigued to see one of these compounds - methyl bromide - in the news this week.  A proposal to build a large methyl bromide fumigation facility to treat logs in the North Carolina town of Delco has been met with anger from locals, who are concerned about potential health and environmental effects of methyl bromide emissions.  Environmental permits indicate that the site could release up to 140 tonnes of methyl bromide a year.

It turns out that the company behind the proposed facility, Malec Brothers Transport, are Australian, and they claim to have been carrying out methyl bromide fumigation at their logging export operations here for many years.  In Australia, methyl bromide is used almost exclusively for quarantine treatment of export goods.  Across the 2013 - 2016 period we used around 700 tonnes per annum, of which about 160 tonnes were used each year for logging.  Not knowing the scale of the operation, it does seem remarkable that the Delco facility is similar in size to Australia's entire methyl bromide emissions for timber. It appears important to now ask why the proposed facility in Delco is so large, and if the company has prior experience operating on a similar scale in Australia.

There are alternatives to methyl bromide fumigation, and under the Montreal Protocol its use worldwide is declining.  The European Union, for instance, have managed to successfully phase out methyl bromide fumigation completely.  It is also possible to re-capture methyl bromide following fumigation, significantly reducing emissions.  Hopefully we continue to see these practices adopted globally, including in Australia and North Carolina.


  1. Thank you so much, I live in Delco, thank you for this information.

  2. Thank you Sir! Would you consider submitting public comments to NC DEQ? It seems that many things the Malec Brothers are claiming are difficult to validate for us in North Carolina! I tried looking for their similar plant that they claim to run in Australia and could not find any information on it. We would greatly appreciate your help!


Post a Comment