ISA CAP Safety & Regulatory Compliance 2

Question 1

Which IEC standard defines the functional safety requirements for electrical/electronic/programmable electronic safety-related systems?

Accepted Answer

IEC 61508

Answer

IEC 61508 is the foundational functional safety standard for E/E/PE safety-related systems across all industries.

Question 2

In a Safety Instrumented Function (SIF), what is the primary purpose of the final element?

Accepted Answer

To take action to bring the process to a safe state

Answer

The final element (e.g., valve, motor) executes the protective action to move the process to a safe state when a demand occurs.

Question 3

What does 'proof test interval' refer to in the context of functional safety?

Accepted Answer

The periodic test performed to reveal dangerous hidden failures

Answer

Proof test interval is the time between scheduled tests designed to detect dangerous undetected failures in safety instrumented systems.

Question 4

Which US regulation requires Process Hazard Analysis (PHA) for highly hazardous chemicals?

Accepted Answer

OSHA PSM Standard (29 CFR 1910.119)

Answer

OSHA's Process Safety Management standard (29 CFR 1910.119) mandates PHA for processes with highly hazardous chemicals above threshold quantities.

Question 5

What is the meaning of 'SFF' (Safe Failure Fraction) in IEC 61508?

Accepted Answer

The ratio of safe failures to total failures

Answer

SFF is the ratio of the sum of safe failure rates plus dangerous detected failure rates to the total failure rate.

(ISA CAP) ISA Certified Automation Professional Practice Test