This week I have been working with a new member who has become frustrated with all the different directions and “interpretations” regarding OSHA’s and EPA’s Maximum Intended Inventory requirements. This is my e-mail response – names and titles have been changed to protect the innocent! (LOL)
I feel your pain, this one small topic has cost the NH3 refrigeration industry millions, and it was a waste of $ when speaking regarding “process safety”!!!
- The WORD document titled “what OSHA says” is correct, but neither of the highlighted areas in that document is referring to the MII requirements. They are relating to EPA RMP and your Quantity reported in your RMP and the way you have to declare the pounds in your WCS.
- Brian’s article is MUCH closer to reality, but even Brian’s article is missing the “intended” part of the Maximum “intended” inventory. Just because my vessel can hold 80% does not mean I have to state that is the MII. He wrote that as a CYA way of establishing your MII so that OSHA/EPA could not take issue with your MII. It is NOT incorrect but is written regarding “compliance” and not true process safety.
- I typically like the work of the XXXXXXXXXX, but in the article you attached, they could not be MORE WRONG. This straightforward sentence flies in the face of true “process safety,” including OSHA/EPA compliance!
“For the purposes of establishing whether or not a given system is a covered process, one needs to determine the “maximum intended system inventory.”
Determining the application of PSM/RMP requirements has ZERO to do with your Maximum Intended Inventory (MII). I mean ZERO! If that were the case, then every process that “could hold” more than the established PSM/RMP Threshold would be covered and that is just NOT factual or sound risk management. This flies in the face of why OSHA and EPA chose the Threshold Methodology to establish PSM/RMP requirements… to get companies to lessen their quantity of the HHC/EHS so to reduce the catastrophic consequences. There are millions of processes that would exceed the threshold if the process was filled to its maximum capability, but the business chose to change the way they manage their inventories and thus no longer have a PSM/RMP covered process.
In ammonia refrigeration, we have to separate MII numbers from the actual “charge” numbers. The “charge number” is used to establish PSM/RMP applicability, and that number needs to match up to our material and energy balance number. In other words, what was the process designed for and that includes how much NH3 does it need to meet that design.