Low-Range Monitoring

June 2024 edition: by Trevor Bowling

When thinking about low-range monitoring, there could be many reasons why we do it. One could be clearing a building after running aeration post-treatment. It could also be you are within the buffer zone of a treatment that requires constant monitoring. When entering a confined space, you need to have low-range monitoring. There are lots of places where low-range monitoring is a must.  

During the initial shoot of a fumigation is a very important time to be monitoring for low range. It will detect leaks around the area in which gas is being applied, as well as any leaks in the structure being fumigated. Doing this can save gas exposure to the fumigation and can save the fumigation from being unsuccessful.

When clearing a structure after using Profume, we have to reach the TWA (Time Weighted Average) to release the structure back over and take the placards off. The TWA for Profume is 1ppm. There is a (STEL)  Short-Term Exposure Limit of 10ppm for Profume as well. This gives the fumigators 15 min to seek fresh air in case they stumble on a pocket of fumigant trying to clear a structure. The monitor used for low-range profume at FSS is called SF-ExplorIR, made by Spectros Instruments.

After fumigating with Phosphine, FSS utilizes Drager XAM-5000 and PAC-7000 to detect the levels of phosphine to deem the structure or space clear. Phosphine has a TWA of .3 ppm. With a STEL of 1ppm. The most common times to monitor for phosphine would be on grain sites with grain bins being treated with phosphine or in the lot next to trailers being treated.

With Methyl Bromide, low-range monitoring is always required inside of the buffer zones. This will keep you informed of readings during your high chances of exposure. The Cub ION is a digital monitor that detects methyl bromide, however, can’t be used to gas-free methyl bromide. Clearing a methyl bromide fumigation requires what is called a Pump and Tube. After aeration, the fumigation will not be cleared if over 5ppm.

Please note, that on every fumigation, it is required to have proper respiratory PPE on hand when working with fumigants. If clearing a building or a bin and you hit a pocket within the STEL, don’t panic. Just get to fresh air and put on proper PPE when going back in. Make sure all monitoring equipment is calibrated when using on a fumigation and be safe!