Why Is Safety So Hard?

“The future of process plant safety is inherently safer design. Inherently safer design can be defined as the design of processes and products with specific attention to eliminating hazards from the manufacturing process, rather than relying on the control of these hazards,” says Kaulfersch.

He says there are four questions designers should ask when they have identified a hazard. 

1. Can I eliminate this hazard?
2. If not, can I reduce the magnitude of the hazard?
3. Do the alternatives identified in questions 1 and 2 increase the magnitude of any other hazards or create new hazards?
4. What technical and management systems are required to manage the hazards which inevitably will remain?

He says a chemical process is described as inherently safer if it reduces or eliminates one or more process hazards, and if this reduction or elimination is accomplished through changes that are permanent and inseparable. Approaches to the design of inherently safer processes and plants have been grouped into four major strategies:

1. Minimize—Use small quantities of hazardous substances.
2. Substitute—Replace a material with a less hazardous substance.
3. Moderate—Use less hazardous conditions, a less hazardous form of materials or facilities that minimize the impact of a release of hazardous material or energy.
4. Simplify—Design facilities that eliminate unnecessary complexity and make operating errors less likely and that are forgiving of errors which are made. For example, intrinsic safety wiring practices ensure that errors will not cause an electrically induced accident.

Protect Personnel First

The first goal of any safety program should be protection of personnel, and the best way to protect people is to get them out of harm’s way before accidents occur.

“Minimizing personnel within the plant exposes fewer people to risks,” says Warren Thompson, now retired but formerly with Citgo. “When I worked at Citgo, they moved their central control room outside of the refinery’s fence, and the console operators never entered the plant. Moving the control room outside the fence meant that it didn’t need to be blast proof.”

“Many gas plants operate in remote sites without on-site staff, and pipelines are operated from remote control areas. There is no reason why refineries and chemical plants cannot operate the same way,” he adds.

Industry veteran Romal Bhullar of Fluor seconds Thompson’s points. “Digital devices, fieldbus communication and closed-circuit television are reducing the need to be in process units or next to dangerous equipment for startup or monitoring. Remote monitoring also allows plants to bring external resources to bear when needed,” observes Bhullar.

“The location of control buildings needs to be revisited in light of current automation technologies. Most units don’t require local control rooms. Some refiners have operator shelters dangerously close or even in the explosion zones; a serious effort should be made to locate these to a safe environment,” says Bhullar.