This has been a huge battle in the power generation and semi-conductor industries! To me, it is very clear – as soon as the trailer is “dropped”, meaning the semi that was pulling the tube-trailer has been detached, then that trailer becomes a “stationary process”. EPA has several documents making this point and for those who visit my PSM/RMP Case Page you have seen first hand that EPA issues citations against this practice. But last month, EPA issued their official position regarding “tube-trailers”…
Tube trailers carry bulk liquids that are stacked in a rack-type arrangement on the back of a truck trailer. This arrangement often is used to carry highly hazardous materials such as anhydrous hydrogen chloride. The tubes are manifolded together, but usually, only one tube at a time is connected to a process for loading and unloading.
Are “tube” trailers considered a single process?
If the “tube” trailers remain in transportation, the contents of the trailers are exempt from threshold determination. If the tubes no longer are in transportation, the entire grouping of tubes must generally be considered a single process, since they are co-located such that they could be involved in the same accident.
Source: https://www.epa.gov/rmp/are-tube-trailers-considered-single-process