CARO Emergency Response and Safety 2 — Questions and Answers
Question 1: What is the IDLH (Immediately Dangerous to Life or Health) concentration for ammonia established by NIOSH?
- 50 ppm
- 300 ppm (Correct answer)
- 1,000 ppm
- 5,000 ppm
Correct answer: 300 ppm
NIOSH lists 300 ppm as the IDLH concentration for ammonia.
Question 2: What is the OSHA permissible exposure limit (PEL) for ammonia as an 8-hour time-weighted average?
- 25 ppm
- 35 ppm
- 50 ppm (Correct answer)
- 100 ppm
Correct answer: 50 ppm
OSHA 29 CFR 1910.1000 sets the ammonia PEL at 50 ppm TWA.
Question 3: An operator gets liquid ammonia splashed in the eyes. What is the correct first-aid action?
- Apply a neutralizing vinegar solution
- Flush with clean water for at least 15 minutes (Correct answer)
- Cover the eyes with a dry bandage and wait for EMS
- Rub the eyes gently to remove the liquid
Correct answer: Flush with clean water for at least 15 minutes
Immediate, continuous flushing with water for at least 15 minutes is the standard first aid for ammonia eye exposure.
Question 4: Because anhydrous ammonia vapor is lighter than air, where would a leak typically accumulate in an enclosed machinery room?
- Near the floor
- Near the ceiling (Correct answer)
- Evenly at mid-height only
- In floor drains and pits
Correct answer: Near the ceiling
Ammonia vapor has a density of about 0.6 relative to air, so it rises toward the ceiling.
Question 5: Where should the emergency shutdown switch for a refrigeration machinery room be located?
- Next to the main compressor control panel inside the room
- Outside the machinery room, near the principal entrance (Correct answer)
- In the plant manager's office
- On the roof near the condenser
Correct answer: Outside the machinery room, near the principal entrance
Codes require the emergency stop to be outside the machinery room so it can be activated without entering a contaminated area.
Question 6: Which type of respiratory protection is required for entry into an ammonia atmosphere at or above IDLH levels?
- Half-face air-purifying respirator with ammonia cartridges
- Full-face air-purifying respirator
- Self-contained breathing apparatus (SCBA) (Correct answer)
- N95 dust mask
Correct answer: Self-contained breathing apparatus (SCBA)
Atmospheres at or above IDLH require supplied air such as positive-pressure SCBA.
Question 7: Within what approximate concentration range in air is ammonia flammable?
- 1% to 5%
- 5% to 10%
- 15% to 28% (Correct answer)
- 40% to 60%
Correct answer: 15% to 28%
Ammonia has a flammable range of roughly 15-28% by volume in air, a range only reached in severe releases.
CARO Emergency Response and Safety 2
What is the IDLH (Immediately Dangerous to Life or Health) concentration for ammonia established by NIOSH?