One of the most popular PSM requests I get is for an example of a “change to facilities that affect a covered process”. In this article, I hope to provide an actual example and how a “change to facilities” can affect an ammonia refrigeration facility. OSHA’s PSM standard states the following about managing changes…
(l) Management of change. (1) The employer shall establish and implement written procedures to manage changes (except for “replacements in kind”) to process chemicals, technology, equipment, and procedures; and, changes to facilities that affect a covered process.
In my real-life example I hope to convince many of you that this scenario, which is very common within the food industry, will not only impact your MOC program but your PSSR program as well, as this “change in facilities” at a refrigeration facility (built after 1992) will IMPACT your Process Safety Information as well. Here is what happened:
A food production facility is growing exponentially and in doing so they are running out of space to grow. As a “temporary fix” they decided to add two more production lines to one of their refrigerated spaces. These spaces were DESIGNED to maintain a temperature of 42ºF assuming so many workers in the room and all the processing equipment. Heck, the design engineers even considered the amount of feedstock that could be placed into the room before processing as this too was a heat load. The room was NOT over designed in the beginning so the addition of these two new processing lines was going to add a heat load to the ammonia refrigeration process.
This plant was built in 2001, so the plant is required to have a “Material and Energy Balances” for its covered process, which it does. And this is where things get interesting! The material and energy balances were very detailed and included all the “assumptions” that went into the “refrigeration sizing” of each of the refrigerated spaces.
During our audit, we continued to hear about temperature issues in the production rooms and we heard the frustration from the refrigeration techs who are challenged to maintain critical temperatures in these rooms. So we begin to inquire about the issues and why this relatively new plant is having these basic refrigeration issues. One quick look that the Material and Energy Balances for each refrigerated space and comparing these to the actual operations taking place within the space it was easy to find the problem(s). Most rooms had at least twice the number of people and equipment as they were designed to handle and in some cases, the equipment used was actually intended to produce heat – I kid you not; but when you’ve run out of open square footage, you “put equipment in those less than desirable locations”.
We then moved to the engine room and began to investigate the impact these changes were having on the covered process and there were many. Here are some of the bigger issues we found that were DIRECTLY related to the crowded refrigerated spaces:
- exceeded their established Maximum Intended Inventory, as they thought more ammonia was the answer to their problems (not once but three times);
- changed the safe upper limits for the level in their vessels in order to hold the increased ammonia charge;
- disabled safety systems so the process vessels could be operated over the established/designed safe upper limit;
- changed their pressure set points and compressor cutouts so they could routinely run over 230 psi (PSVs set at 250);
- “manually purging” (without a procedure/PPE assessment/training) since the auto-purger was not sized for their increased quantities of NH3;
I should point out that these changes took place over approximately 1.4 years, one at a time and NONE were accompanied by an MOC or any type of engineering review; not even an entry into the “log book”. In fact, the crew running the process at the time of our audit all had less than 6 months at the facility and were nearly ignorant of these changes. Although to their credit, the four main technicians were starting to discover that some safety systems had been disabled because the process conditions they were experiencing without any alarms or safety systems tripping were not the way they had been trained. The new engineer was attempting to explain to management why they were experiencing their temperature control issues, but the damage was already done!
This all came about because management wanted to put more “production and equipment” within refrigerated spaces that were NOT designed to handle it. This “change to facilities” brought about a ripple effect that leads to many unsafe process safety decisions that clearly took the process well outside its established process safety envelopes. So even an increase in production can have an impact on process safety when the “change to facilities” is not managed properly.