Which of the following is typically considered a barrier in process safety?

• A. Marketing plan.
• B. Employee benefits.
• C. Travel policy.
• D. Alarms, procedures, and intrinsically protective limits (IPLs).

Answer: (D)

In process safety, barriers are layers of protection designed to prevent a release or limit its consequences. These can be alarms that alert operators to abnormal conditions, procedures that guide safe operation and response, and intrinsically protective limits that keep process conditions within safe ranges. Together, alarms, procedures, and IPLs form a protective barrier system that helps stop hazards from escalating.

The other options don’t function as barriers in this context. A marketing plan, employee benefits, and a travel policy are business or administrative policies and don’t provide safeguards against process hazards or mitigate their consequences.