Hyrarchie of Barriers in Process Safety
Yesterday, in a tool box talk with Maintenance team, I shared about the importance of each individuals to play their roles to pervent process safety incidents. I started with introducing the five hyrarchie of barriers in Process Safety. The best barrier (1) is called Elimination, i.e: try to eliminate the hazards in the first place. I explained the limitation of this barrier by taking example that the hazard of hydrocarbon gas can not be eliminated. It is our business to process the gas into LNG. The next barrier (2) is less effective called Substitution. This is the efforts to change the hazardous material or processes with the least hazardous. I give an example of heating media using diesel fuel would be less hazardous if we changed it with using steam or hot oil.
The next barrier (3) is called Engineering Controls. We apply engineering solutions to keep the hazards under control in its containment. It could be by putting alarms, automatic safety instrumented system (SIS), applying international codes and standards, installing pressure safety valves, or automatic fire suppression system.
This barrier also has weaknesses which requires to be covered using the next barrier (4) called Administrative Controls. This is all the system and procedures which we put in place to prevent and mitigate incidents. It relies most to the human factors.
The last barrier (5) is called Personnal Protective Equipment. This is the least effective barrier. However, it is important to minimize the extent of the damage or injury resulted from the incident.
In operating plant like us at Donggi Senoro LNG, most of the time we are dealing with the Administrative Controls barriers. Although it sounds like a paper work, if everyone in our organization making sure what they are writing down or sign is true and reflecting the real condition, it is no more a paper work. It could become a real tool to save us from process safety incidents. One simple example is in the permit to work system a field operator shall only sign it if he has checked and making sure the condition is safe for maintenance crew to start their work.