Most facilities will have a piece of equipment that is so large and complex that it will entail isolating many sources of all types of energy in order to get the entire system to a zero energy state (ZES). But what do we do when we have a task that involves exposure to only one (1) energy source? Do we expect the worker(s) to lock out all the isolation devices, or can they merely lock out those devices that will protect them during their specific task? The answer is easy, but the implementation of the practice is a lot of work – work that many businesses do not want to invest in. Here is how it looks and functions…
We have a large piece of equipment and if we wanted this piece of equipment to be at a ZES, it will entail locking out 16 isolation devices. However, we only need to work to clear some small screens/filters within the piece of equipment. While doing this task, we are exposed to two (2) energy sources:
- The filler rollers mechanical hazards
- The chemical (High pH of 14 and 50% concentration)
The other forms of hazardous energy are NOT impacting our safety – we just need to isolate and control the energy sources within the “cabinet” we are working in and that is a simple electrical lockout of the chemical pump, locking out the inlet and outlet valve(s) for the filter/screen bed, AND locking out a chain and sprocket within the cabinet. Even though we are not going to be working on the chain/sprocket, it poses a HAZARD to us while we are working inside this cabinet, thus this power transmission device must be locked out to protect us while we are working within the cabinet.
So how does a mechanic make this determination… which energy sources need to be locked out and which ones do not?
That is answered by the maintenance procedure, which will include the LO procedure for the task(s), as well as the PPE needed. So in order to effectively manage LOTO to this level, it is imperative that we have specific procedures for the tasks associated with this large and complex piece of equipment. The alternative is that the mechanic(s) doing the screen/filter work will have to position and lockout all 16 isolation devices that are identified on the equipment-specific energy isolation procedure.
But with a detailed maintenance procedure for “clearing screens/filters”, we evaluate the hazards associated with the specific task and identify the energy sources (including those not associated directly with the task(s), but still pose a hazard for the worker(s) in the area).
So instead of taking the time to lockout isolation devices that have absolutely nothing to do with our task, we can effectively evaluate the task(s) and the hazards and break down the 10 page LOTO procedure for the entire machine and require ONLY those isolation devices necessary for the specific tasks be locked out.
Please realize that these maintenance procedures need to be reviewed annually as they in fact include lockout procedures and for this single piece of equipment we could have an additional 10-20 LOTO procedures. I also suggest that these procedures be included in the management of change practices at the facility to ensure any changes to this equipment will consider the LOTO procedures that are embedded in the maintenance procedures for the equipment.