Static Electricity Hazards and Prevention – How to Prepare for It

 By Lukman Nulhakiem

1

Static electricity hazards are ones of potential hazards that are commonly found in chemical plant. According to wikipedia.org, it is defined as an excess of electric charge within or on the surface of a material. The charge remains until it is able to move away by means of an electric current or electrical discharge. If it is not properly treated, static electricity could create electrical discharge in form of sparks. This is an ignition source that can ignite flammable vapor or gas readily.
Recently, I have experienced with such hazard, where improper treatment of static electricity hazards was the main cause. The static electricity was happened when dry metal catalyst was charging into a stainless steel vessel.

How to Prepare for Static Electricity Hazards and Prevention

It is not good habit if we do improvement after an incident occurs. But sometimes, an incident could uncover unsafe operation or improper procedure that so far could not be detected or identified.
Or operators won’t tell you an incident that may frequently occur but they did not report it to you. They may think that as long as they can overcome that incident that’s no problem not to report it.
Let’s back to my recent experience with static electricity hazards. After that fire incident occurred, which was triggered by static electricity, I took some lessons in order to prevent such incident in the future. Of course I would like to share them here with you, my valuable readers.

1. Grounding cable was not in good condition. Its resistance was over allowable resistance (standard). There was no regular inspection on its condition. Regular checking, measurement and visible checking, is necessary.
2. Grounding cable might be no enough to avoid electricity discharge from happening. At that  time, it was only one grounding cable used. Further study should be done to decide single grounding cable is enough or not.
3. There was no flammable gas or vapor checking before charging metal catalyst into catalyst feeder or vessel, after nitrogen gas substitution. There might be a source of flammable gas leakage into the vessel where catalyst is charged into it.
4. Flammable gas or vapor isolation was not properly done. There was no log-out / tag out procedure done to prevent unintended flammable gas  or vapor into catalyst feeder.
5. Parallel operation was done by operators in order to shorten the time without any notification or approval from their supervisor/manager. Unfortunately, this operation was done with less safety consideration.
6.  Improper type of portable fire extinguisher was installed near the catalyst feeder. For type of potential fire it is suitable. But it will contaminate process liquid if it is used to put out fire that directly contact with it.
7. Safety consideration was not adequately given to the required number of personnel for doing such risky job at different floor level even though it takes only several second to climb up or down.