Overrating Hazardous Areas

[LouisG]

I work in a chemical facility where the entire production area is rated as a Class I Div I area. I am very confident that it should be Class I Div II and long time employees said it was rated Class I Div I just to be conservative.

My question is what are the advantages and disadvantages to over classifying the area? I'm not talking about just financially but also from a safety, and employee perception, attitude and work practices standpoint.

 

[controlnovice]

As you alluded to, the biggest disadvantage is financial. Not just in the initial equipment and installation, but for maintenance or adding something in the future.

Often companies overrated for CYA. Plus, it did make it more simple to maintain spares that are rated for the same area. Having the same spares is a cost savings (no need to keep multiple instruments, motors, etc for difference areas). Also by keeping one area, you minimize the error of someone putting something in that isn't rated for the area.

There could be a safety disadvantages of over rating: employees not replacing the equipment correctly, or taking shortcuts.
Employees usually don't like working on Class I Div I equipment because of the extra work involved in opening and closing the equipment (j-boxes in particular). I've seen alot of boxes that didn't have all of their bolts in place. I've even seen the bolt heads cut off and welded in place to make it look like they were secure.
Disadvantage is work practice could suffer, reducing the safety for the employees.

How much difference between Div 1 and Div 2 for employee shortcuts or errors is anybody's guess.

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[LouisG]

Thank you for your response, I appreciate it. One of the concerns I have is if the area is rated Div I when it is not is this:

Employees in the area become complacent, "Yes it is Div I but there is very little danger to using this (pick your own tool) just once." Then they are confronted with a true Div I area and they think "This is no big deal. I've worked in these areas before and they always say it is worse than it is."

Just me thinking out loud. I wish I had the answer.

 

[resqcapt19]

Louis,
You make a very good point that the employees will become complacent if an area is over classified.

Another issue I have is letting anyone one even enter a Class I, Division 1 area without full PPE for the chemical(s)that resulted in the classification or atmosphere testing to prove the area is safe for human occupancy. For a number of flammable vapors you have an Immediately Dangerous to Life and Health (IDLH) atmosphere at 10% or less of LEL.

 

[LouisG]

I agree completely. Off the top of my head I can't think of a chemical that doesn't become an exposure concern long before it becomes a flammability concern.

 

[controlnovice]

While it might be an initiator to the discussion, Electrical Classification should not be used for determination of PPE.

Classification is strictly for electrical references for those using NEC(Some mechanical references in Europe).

Full PPE: Does that include acid/chemical suit with SCBA?

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This is normally the space where people post something insightful.

 

[LouisG]

I agree the Electrical Classification shouldn't be used to determine PPE but it is (or should be) an indicator of the types of hazards that are in the area. In my old place of employment we had Class I, Div I areas and they were not really Div I areas but closer than the areas here. What we did have was a continuous air monitoring system for the production area. If concentrations got up to the TWA (2 ppm)then a light flashed and respirators were required.