I don’t think many safety pros would argue with this statement: LOTO requires that all forms of hazardous energy be taken to a ZES before servicing and maintenance begin.
But I have had many discussions about DEFINING and QUANTIFYING what a “hazardous form of energy” is. Since OSHA has not quantified the term “hazardous energy”, many written LOTO programs and training programs do NOT define and quantify which energy sources require LOTO. Yes, we can say ALL energy sources must be taken to their ZES, and we would be covered, but is this reality?
It is clear that all forms of “hazardous energy” must be taken to their ZES, but how we DEFINE and QUANTIFY what a “hazardous energy” source is MATTERS IMMENSELY to the proper scope and application of our program. Here is how OSHA trains their CSHOs to define “hazardous energy”:
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Hazardous Energy. Any energy, including mechanical (e.g., power transmission apparatus, counterbalances, springs, pressure, gravity), pneumatic, hydraulic, electrical, chemical, nuclear, and thermal (e.g., high or low temperature) energies, that could cause injury to employees. Danger is only present when energy may be released in quantities or at rates that could injure employees. NOTE: Thermal energy may be generated as a result of electrical resistance, mechanical work, radiation, or chemical reaction, such as is the case with anhydrous ammonia, chlorine, or sulfuric acid reacting with skin, lung, or eye tissue causing chemical burns. Hazardous chemical energy, for purposes of this standard, includes chemicals (e.g., flammable and combustible liquids; flammable gases; acids and alkaline chemicals) that may thermally produce burn injury through high or low temperature. |
In 2018, I wrote about a situation I ran into in the 1990s that taught me a valuable lesson regarding the scope and application of LOTO. It involved changing out a water fountain filter, and the mechanic followed the program and the training to the letter. This was a “closed system” that had “energy” that needed to be isolated for him to get a line/break permit. I can’t argue with his actions because that is precisely what our program and training required.
So, does our LOTO program DEFINE and QUANTIFY which energy sources are “hazardous”? In this post, I will use the two most common forms of energy found in every workplace:
- Water
- Compressed Air
Water
Using the water fountain filter situation, how many of you have a program that lists “water” as a form of energy that falls within the LOTO program’s scope?
Water at standard temperature (68F) and pressure (14.7 psi) is not typically considered hazardous energy. Anyone who wants to debate this, first show me you have your water hoses labeled per ASME A131.1 (color-coded label with directional flow and the word water). So the question becomes, what parameters make a water source a hazardous form of energy requiring our personnel to apply LOTO?
We have to consider at least three (3) characteristics that could make water a hazardous form of energy that would fall within the scope of LOTO:
- Temperature
- Pressure
- pH
NOTE: Water would also have to be considered a hazardous form of energy at Standard Temperature and Pressure (STP) when it involves engulfing an entry within a PRCS, meaning VOLUME would be another characteristic to consider in the scope of working within a PRCS.
How many of our programs have established the limits for when water becomes a form of hazardous energy by Temperature, Pressure, and pH?
It is hard to argue water over 140F is not hazardous as contact with that water would produce a 2nd-degree burn. CPSC states the following:
Most adults will suffer third-degree burns if exposed to 150-degree water for two seconds. Burns will also occur with a six-second exposure to 140-degree water or with a thirty-second exposure to 130-degree water. Even if the temperature is 120 degrees, a five-minute exposure could result in third-degree burns.
Quantifying the pressure at which we declare water a form of hazardous energy can be a bit tricker. Most would say water at 1,000 psi is hazardous. But what about 100 psi, ten psi, or one psi? Remember, PSI can fool a lot of folks, as some do not fully understand the principle behind Pounds-per-Square-Inch and how the surface area holding the water plays a role in the magnitude of just 1.0 psi.
Even when water is at Standard Temperature and Pressure (STP), the pH of water can certainly make it a form of hazardous energy. And yes, not to get too technical, concentration is a better means to establish the hazard of an acid or a base, but here we are talking about water from a process or maybe “wastewater” with a measurable pH. We consider a pH of 7.0 “neutral”; less than 7.0 is called an acid, and greater than 7.0 is called a base. How far off of 7.0 do we declare the water a “hazard” or a “hazardous form of energy” as it would apply to the scope of our LOTO program and, for some, their Line Break/Equipment Opening SWP?
Be careful thinking this is just silly… “just lock it all out.” Being naive in applying LOTO can set our workers up for serious failures. When I run into this way of thinking, I simply ask this of management, including some safety pros:
is it a LOTO violation to turn off the water at the facet, unscrew the spray nozzle on the end of the hose, and replace it with a different nozzle without having locked out the water valve the hose is connected to?
See, without defining and quantifying our hazardous energy sources and making blanket statements such as “just lock it all out,” we will set up workers for discipline that makes no sense! Because I know of no one who would proclaim that changing the nozzle on a water hose is a LOTO function!
Air
Pressure gets a bit more tricky as we always use PSI as our means to quantify our level of energy with air; however, in many situations, it is not the contact with the air that is the hazard rather it is the amount of pressure AND VOLUME needed to mover a piece of the machine/equipment while the worker performs the servicing and maintenance. In this latter case, we must ensure the air is at a ZES. But let’s consider a worker needing to change a valve in an air system.
The first scenario is they will be changing a tiny valve on a machine where the pressure is 1.0 psi on 0.05″ steel tubing. Does this scenario equate to the worker applying LOTO to this scope of work? How many of us have lockout devices this small to apply to a ball valves 0.05″ in size? Remember, the air is also a form of STORED energy source, so it would also require this air psi to be bled down to achieve a ZES and then have a means to ensure the isolation devices do not bleed by allowing the area of work to be energized.
The second scenario for compressed air is working on the plant’s main air header, which is 6″ in diameter and operates at 150 psi. This is the other end of the spectrum, and most safety pros can agree that changing out a valve in this system is clearly a LOTO task. But I have debated that air, even at 150 psi in 6″ piping, is not a form of hazardous energy simply because “it is air Bryan.” I have been told this more times than I even wish to admit!
The bottom line is that if we do not DEFINE and QUANTIFY the forms of hazardous energy that we list in our LOTO program “scope/application” section(s), we are setting ourselves up for a bad accident or one day we will be faced with disciplining a great employee who decided that LOTO did not apply to a specific form of energy on a specific piece of machinery/equipment while performing a routine task that had been completed millions of times before without LOTO being applied.