A term not even mentioned in OSHA’s 1910.119 or EPA’s Part 68, but a term that has huge impacts on process safety. So what is a “Battery Limit” in the context of Process Safety? I use the definition provided by AICHE…
The perimeter of a specific manufacturing process area. It is often defined by the roads around the perimeter. This area will include process equipment, and may include in-process tankage.
A quick Google Gemini result says:
The term "AIChE battery limits" does not refer to a specific technical standard but to the concept of a "battery limit" in chemical and process engineering, as defined by the American Institute of Chemical Engineers (AIChE). It represents the physical or conceptual boundary of a plant or process unit, beyond which the responsibilities of one party end and another's begin. This is crucial for defining scope in contracts and ensuring safety.
One major impact the battery limit(s) will have is on Contractor Safety. I have been using the phrase “in, on, and adjacent to” for 30+ years. And this phase is from OSHA writings (including the PSM preamble). Without established battery limits, we may never have a “safety trip” as to when a contractor is a “PSM/RMP Contractor”. By establishing these battery limits, we are literally drawing a line in the sand of safety, and when that line is crossed by anyone and everyone, they know they are inside battery limits of a hazardous process. Keep in mind, some people will be INSIDE the battery limit, but they will be just working INSIDE the process battery limits. Some will be working ON the process. And some may be ADJCENT to the process, whereas they could either: 1) IMPACT the covered process or 2) BE IMPACTED by the process.
So, how does one create this line in the sand for their process battery limit?
The answer is NOT simple! It depends on the process chemicals and pressures for the most part. So this is why a lot of businesses will use some well established distances when setting their battery limits. Such as:
- Electrical Classification Distances: Inside 25′; Outside 10′
- Hot Work Distance of 35′
PLEASE UNDERSTAND, these are just some distances to start the analysis and are NOT meant to be sure-fire safe distances. The size of the process, the properties of the HHC/EHS involved in the process, and the impacts of an LOPC event are some of the factors to be considered. But we are trying to establish an invisible forcefield around our process in order to KEEP PEOPLE OUT who do not have the need/permission to be there.
Once we establish our battery limit(s), we MUST demarcate these boundaries so it is clear to all as to when they have crossed the battery limit line and are now within our battery limit. This needs to be a physical demarcation with barriers or at least easily visible signs.