South Carolina Cleanroom Installer
Certification License Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. In cleanroom classifications, an ISO Class 7 room allows a maximum of
how many particles ≥0.5 µm per cubic meter of air?
A. 352,000
B. 352,000,000
C. 3,520,000
D. 35,200,000
Rationale: According to ISO 14644-1 standards, an ISO Class 7 cleanroom
permits up to 352,000,000 particles ≥0.5 µm per cubic meter, reflecting its
allowable contamination level._
2. Which type of airflow pattern is most effective at removing
contaminants from a critical work zone?
A. Turbulent airflow
B. Laminar (unidirectional) airflow
C. Recirculating airflow
D. Cross drafting
,Rationale: Laminar or unidirectional airflow moves air in parallel streams
at uniform velocity, sweeping contaminants away efficiently, making it
ideal for critical zones._
3. HEPA filters are rated to capture at least what percentage of particles
≥0.3 µm?
A. 75%
B. 90%
C. 95%
D. 99.97%
Rationale: True HEPA filters are defined by their ability to remove at least
99.97% of particles 0.3 µm in diameter, which is a standard performance
specification._
4. What is the primary purpose of gowning when entering a cleanroom?
A. To show employee compliance
B. To reduce static electricity
C. To prevent personnel-generated contamination
D. To improve worker comfort
Rationale: Gowning is essential to minimize shed particles, fibers, and
microbes from personnel, thereby maintaining the cleanroom’s controlled
environment._
5. In a cleanroom HVAC system, what is the function of an air change
rate?
A. To reduce humidity
B. To lower energy costs
C. To dilute and remove airborne contaminants
D. To maintain building pressure only
, Rationale: Air change rate refers to how frequently the air is replaced or
recirculated, helping to dilute and remove particles and contaminants in a
cleanroom._
6. What organization issues the ISO 14644 standard for cleanroom
classification?
A. FDA
B. ISO
C. EPA
D. ANSI
Rationale: ISO (International Organization for Standardization) publishes
the ISO 14644 series, which governs cleanroom classifications and related
standards._
7. Which of the following garments should be worn in a Class 100
cleanroom?
A. Safety goggles only
B. Lab coat only
C. Full suit including hood, boots, and gloves
D. Surgical mask only
Rationale: A Class 100 cleanroom requires comprehensive gowning to
significantly reduce contamination from personnel, including full body
coverage._
8. What does “cascade pressure” refer to in cleanroom design?
A. Water pressure in plumbing
B. Electrical pressure differential
C. Sequential positive air pressure zones
D. Air velocity at vents
Certification License Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. In cleanroom classifications, an ISO Class 7 room allows a maximum of
how many particles ≥0.5 µm per cubic meter of air?
A. 352,000
B. 352,000,000
C. 3,520,000
D. 35,200,000
Rationale: According to ISO 14644-1 standards, an ISO Class 7 cleanroom
permits up to 352,000,000 particles ≥0.5 µm per cubic meter, reflecting its
allowable contamination level._
2. Which type of airflow pattern is most effective at removing
contaminants from a critical work zone?
A. Turbulent airflow
B. Laminar (unidirectional) airflow
C. Recirculating airflow
D. Cross drafting
,Rationale: Laminar or unidirectional airflow moves air in parallel streams
at uniform velocity, sweeping contaminants away efficiently, making it
ideal for critical zones._
3. HEPA filters are rated to capture at least what percentage of particles
≥0.3 µm?
A. 75%
B. 90%
C. 95%
D. 99.97%
Rationale: True HEPA filters are defined by their ability to remove at least
99.97% of particles 0.3 µm in diameter, which is a standard performance
specification._
4. What is the primary purpose of gowning when entering a cleanroom?
A. To show employee compliance
B. To reduce static electricity
C. To prevent personnel-generated contamination
D. To improve worker comfort
Rationale: Gowning is essential to minimize shed particles, fibers, and
microbes from personnel, thereby maintaining the cleanroom’s controlled
environment._
5. In a cleanroom HVAC system, what is the function of an air change
rate?
A. To reduce humidity
B. To lower energy costs
C. To dilute and remove airborne contaminants
D. To maintain building pressure only
, Rationale: Air change rate refers to how frequently the air is replaced or
recirculated, helping to dilute and remove particles and contaminants in a
cleanroom._
6. What organization issues the ISO 14644 standard for cleanroom
classification?
A. FDA
B. ISO
C. EPA
D. ANSI
Rationale: ISO (International Organization for Standardization) publishes
the ISO 14644 series, which governs cleanroom classifications and related
standards._
7. Which of the following garments should be worn in a Class 100
cleanroom?
A. Safety goggles only
B. Lab coat only
C. Full suit including hood, boots, and gloves
D. Surgical mask only
Rationale: A Class 100 cleanroom requires comprehensive gowning to
significantly reduce contamination from personnel, including full body
coverage._
8. What does “cascade pressure” refer to in cleanroom design?
A. Water pressure in plumbing
B. Electrical pressure differential
C. Sequential positive air pressure zones
D. Air velocity at vents
