ISA CAP Safety & Regulatory Compliance 3

Question 1

What is 'common cause failure' (CCF) in redundant safety systems?

Accepted Answer

A single event that causes multiple redundant channels to fail simultaneously

Answer

CCF is a single root cause event (e.g., common environment, design flaw) that defeats the independence of redundant channels and causes them to fail together.

Question 2

In a 2oo3 voting architecture, how many channels must fail dangerously before a safety function is lost?

Accepted Answer

2

Answer

In a 2oo3 (two-out-of-three) architecture, two channels must fail dangerously before the safety function is lost, providing high fault tolerance.

Question 3

Which document within a Safety Lifecycle defines the target SIL for each Safety Instrumented Function?

Accepted Answer

SIL determination study

Answer

The SIL determination study (using methods like Layer of Protection Analysis or Risk Graph) assigns the required SIL to each SIF based on risk reduction needed.

Question 4

The EPA Risk Management Program (RMP) Rule requires facilities to submit an RMP to the EPA when:

Accepted Answer

A regulated substance exceeds its threshold quantity in a covered process

Answer

The EPA RMP rule (40 CFR Part 68) is triggered when a regulated substance is present in a process above its listed threshold quantity.

Question 5

What is the purpose of a 'bypass management' procedure in a Safety Instrumented System?

Accepted Answer

To control and document temporary defeats of safety functions during maintenance

Answer

Bypass management procedures ensure that temporary SIS defeats for maintenance are authorized, documented, time-limited, and compensated with alternative safeguards.

(ISA CAP) ISA Certified Automation Professional Practice Test

(ISA CAP) ISA Certified Automation Professional Practice Test

ISA CAP Safety & Regulatory Compliance 3