The Complete Custodian Certification
Exam Guide: 400+ Practice Questions
with Answers and Rationales
Questions 1-50: Safety and Chemical Handling
1. What is the first thing you should do if you spill harmful chemicals
on your skin?
Answer: Tell your supervisor immediately
Rationale: Chemical exposure requires prompt reporting so proper medical
attention can be obtained and the appropriate first aid measures can be
taken according to the Safety Data Sheet (SDS) for the specific chemical.
2. What chemicals should you never mix together?
Answer: Chlorine bleach and ammonia
Rationale: Mixing bleach and ammonia creates toxic chloramine gases that
can cause severe respiratory damage, chemical burns, and potentially
death.
3. What does PPE stand for?
Answer: Personal Protective Equipment
Rationale: PPE refers to equipment like gloves, goggles, masks, and other
protective gear used to ensure worker safety during custodial tasks.
4. What type of ladder should be used near electrical sources?
Answer: Fiberglass ladder
,Rationale: Fiberglass ladders do not conduct electricity, providing better
protection against electrical shock when working near electrical ballasts,
light fixtures, or other electrical equipment.
5. What is the correct way to lift heavy objects?
Answer: Bend your knees and keep your back straight
Rationale: Proper lifting technique prevents back injuries by using leg
muscles rather than back muscles to bear the weight.
6. What is the proper dilution method for concentrated cleaning
products?
Answer: Follow the directions on the label
Rationale: Using the correct dilution ensures effective cleaning and
prevents chemical damage to surfaces or unnecessary waste.
7. When should you wash your hands during custodial work?
Answer: After using chemicals, after cleaning restrooms, and before eating
or drinking
Rationale: Frequent handwashing prevents chemical exposure and reduces
the spread of germs and contaminants.
8. How should trash bags be carried to prevent injury?
Answer: Held close to the body with both hands
Rationale: Proper carrying technique reduces strain on the back and arms
and minimizes the risk of spills or dropping the load.
9. What is the safest type of protective glove for handling strong
solvents?
Answer: Nitrile or heavy-duty neoprene chemical-resistant gloves
Rationale: Solvents and harsh industrial chemicals quickly degrade thin
latex and penetrate woven fabrics. Heavy-duty nitrile or neoprene gloves
provide the required chemical barrier.
,10. What is Lockout/Tagout procedure designed to prevent?
Answer: Machines accidentally starting during maintenance or repair work
Rationale: Lockout/Tagout procedures physically isolate energy sources
from machinery being serviced, protecting workers from unexpected start-
ups or electrical discharges.
11. What is the first thing to do if a fire starts?
Answer: Sound the alarm and notify others
Rationale: Raising the alarm ensures quick evacuation and emergency
response before attempting to fight the fire.
12. What should you check before using a floor buffer?
Answer: Cord condition and grounding
Rationale: Inspecting cords ensures electrical safety and prevents shock
hazards.
13. What is the best way to clean around computers or electrical
outlets?
Answer: Turn off power and unplug devices
Rationale: Turning off and unplugging equipment prevents electric shock
or damage to sensitive electronic devices.
14. How should bulk chemical containers be stored on shelves?
Answer: On the lowest shelves or ground level
Rationale: Placing heavy bulk containers on low levels reduces structural
strain on shelving units and minimizes the danger of heavy drops, spills, or
operator injury when retrieving products.
15. What should be done if a safety hazard is noticed?
Answer: Report it immediately
Rationale: Prompt reporting ensures hazards are corrected quickly before
they cause injury.
, 16. What does a dilution ratio of "1:64" mean?
Answer: Mix 1 part concentrated chemical into 64 parts of water
Rationale: Ratio notation represents (parts of concentrate):(parts of
diluent/water). A 1:64 ratio equates to adding 2 ounces of chemical
concentrate to 1 gallon of water.
17. What is the standard protocol for cleaning up a bodily fluid spill?
Answer: Apply a bloodborne pathogen spill kit, absorb the fluid, disinfect
with an EPA-registered virucide, and dispose in a biohazard bag
Rationale: Bodily fluids can harbor infectious agents. Universal precautions
demand using absorbent solidifiers, disinfectant solutions, and biohazard
waste disposal.
18. Why should cleaning logs be maintained?
Answer: To record work completed and ensure accountability
Rationale: Logs document tasks for management review, track completion
of duties, and provide compliance records.
19. What is the proper way to store cleaning supplies?
Answer: In a designated, ventilated area
Rationale: Proper storage prevents contamination, reduces exposure to
fumes, and maintains chemical integrity.
20. What is a ballast in a light fixture?
Answer: A fluorescent light fixture component
Rationale: A ballast regulates the electrical current to fluorescent lights and
is a common component that custodians may need to identify.
21. What environmental condition most accelerates mold growth?
Answer: High humidity, poor ventilation, and warm temperatures
Rationale: Fungal spores thrive in environments with moisture, minimal air
movement, and elevated warmth.
Exam Guide: 400+ Practice Questions
with Answers and Rationales
Questions 1-50: Safety and Chemical Handling
1. What is the first thing you should do if you spill harmful chemicals
on your skin?
Answer: Tell your supervisor immediately
Rationale: Chemical exposure requires prompt reporting so proper medical
attention can be obtained and the appropriate first aid measures can be
taken according to the Safety Data Sheet (SDS) for the specific chemical.
2. What chemicals should you never mix together?
Answer: Chlorine bleach and ammonia
Rationale: Mixing bleach and ammonia creates toxic chloramine gases that
can cause severe respiratory damage, chemical burns, and potentially
death.
3. What does PPE stand for?
Answer: Personal Protective Equipment
Rationale: PPE refers to equipment like gloves, goggles, masks, and other
protective gear used to ensure worker safety during custodial tasks.
4. What type of ladder should be used near electrical sources?
Answer: Fiberglass ladder
,Rationale: Fiberglass ladders do not conduct electricity, providing better
protection against electrical shock when working near electrical ballasts,
light fixtures, or other electrical equipment.
5. What is the correct way to lift heavy objects?
Answer: Bend your knees and keep your back straight
Rationale: Proper lifting technique prevents back injuries by using leg
muscles rather than back muscles to bear the weight.
6. What is the proper dilution method for concentrated cleaning
products?
Answer: Follow the directions on the label
Rationale: Using the correct dilution ensures effective cleaning and
prevents chemical damage to surfaces or unnecessary waste.
7. When should you wash your hands during custodial work?
Answer: After using chemicals, after cleaning restrooms, and before eating
or drinking
Rationale: Frequent handwashing prevents chemical exposure and reduces
the spread of germs and contaminants.
8. How should trash bags be carried to prevent injury?
Answer: Held close to the body with both hands
Rationale: Proper carrying technique reduces strain on the back and arms
and minimizes the risk of spills or dropping the load.
9. What is the safest type of protective glove for handling strong
solvents?
Answer: Nitrile or heavy-duty neoprene chemical-resistant gloves
Rationale: Solvents and harsh industrial chemicals quickly degrade thin
latex and penetrate woven fabrics. Heavy-duty nitrile or neoprene gloves
provide the required chemical barrier.
,10. What is Lockout/Tagout procedure designed to prevent?
Answer: Machines accidentally starting during maintenance or repair work
Rationale: Lockout/Tagout procedures physically isolate energy sources
from machinery being serviced, protecting workers from unexpected start-
ups or electrical discharges.
11. What is the first thing to do if a fire starts?
Answer: Sound the alarm and notify others
Rationale: Raising the alarm ensures quick evacuation and emergency
response before attempting to fight the fire.
12. What should you check before using a floor buffer?
Answer: Cord condition and grounding
Rationale: Inspecting cords ensures electrical safety and prevents shock
hazards.
13. What is the best way to clean around computers or electrical
outlets?
Answer: Turn off power and unplug devices
Rationale: Turning off and unplugging equipment prevents electric shock
or damage to sensitive electronic devices.
14. How should bulk chemical containers be stored on shelves?
Answer: On the lowest shelves or ground level
Rationale: Placing heavy bulk containers on low levels reduces structural
strain on shelving units and minimizes the danger of heavy drops, spills, or
operator injury when retrieving products.
15. What should be done if a safety hazard is noticed?
Answer: Report it immediately
Rationale: Prompt reporting ensures hazards are corrected quickly before
they cause injury.
, 16. What does a dilution ratio of "1:64" mean?
Answer: Mix 1 part concentrated chemical into 64 parts of water
Rationale: Ratio notation represents (parts of concentrate):(parts of
diluent/water). A 1:64 ratio equates to adding 2 ounces of chemical
concentrate to 1 gallon of water.
17. What is the standard protocol for cleaning up a bodily fluid spill?
Answer: Apply a bloodborne pathogen spill kit, absorb the fluid, disinfect
with an EPA-registered virucide, and dispose in a biohazard bag
Rationale: Bodily fluids can harbor infectious agents. Universal precautions
demand using absorbent solidifiers, disinfectant solutions, and biohazard
waste disposal.
18. Why should cleaning logs be maintained?
Answer: To record work completed and ensure accountability
Rationale: Logs document tasks for management review, track completion
of duties, and provide compliance records.
19. What is the proper way to store cleaning supplies?
Answer: In a designated, ventilated area
Rationale: Proper storage prevents contamination, reduces exposure to
fumes, and maintains chemical integrity.
20. What is a ballast in a light fixture?
Answer: A fluorescent light fixture component
Rationale: A ballast regulates the electrical current to fluorescent lights and
is a common component that custodians may need to identify.
21. What environmental condition most accelerates mold growth?
Answer: High humidity, poor ventilation, and warm temperatures
Rationale: Fungal spores thrive in environments with moisture, minimal air
movement, and elevated warmth.
