CCST Safety Standards & Regulatory Compliance in Control Systems 3

Question 1

A safety instrumented function must achieve a PFD of 0.01 to 0.001. What SIL level does this correspond to?

Accepted Answer

SIL 2

Answer

SIL 2 corresponds to a PFD range of 0.01 to 0.001 (RRF of 100 to 1,000) per IEC 61508/61511.

Question 2

Under the EPA Risk Management Program (RMP), what is required for Program 3 processes that is NOT required for Program 2?

Accepted Answer

Process hazard analysis

Answer

Program 3 requires a full process hazard analysis (PHA) using recognized methods such as HAZOP, whereas Program 2 uses a simplified hazard review.

Question 3

What is the key distinction between a Safety Instrumented Function (SIF) and a Basic Process Control System (BPCS) function?

Accepted Answer

A SIF is independent of the BPCS and activates on demand to bring the process to a safe state

Answer

A SIF is an independent safety layer that activates on demand to achieve or maintain a safe process state, separate from normal process control.

Question 4

In hazardous area classification, what does Zone 1 indicate under IEC 60079-10-1?

Accepted Answer

An area where explosive gas atmosphere is likely to occur in normal operation

Answer

Zone 1 is defined as an area in which an explosive gas atmosphere is likely to occur in normal operation.

Question 5

Which document type is used to formally record a bypass of a safety instrumented function and track its status?

Accepted Answer

Safety Bypass Override Authorization (SBOA)

Answer

A Safety Bypass Override Authorization (or similar site-specific form) formally tracks SIF bypasses, approvals, duration limits, and compensating measures.

(CCST) Certified Control Systems Technician Practice Test

(CCST) Certified Control Systems Technician Practice Test

CCST Safety Standards & Regulatory Compliance in Control Systems 3