Ammonia Refrigeration Safety Flashcards

What is the OSHA permissible exposure limit (PEL) for ammonia as an 8-hour time-weighted average?

Answer: 50 ppm

OSHA 29 CFR 1910.1000 sets the ammonia PEL at 50 ppm as an 8-hour TWA.

At what concentration does NIOSH consider ammonia Immediately Dangerous to Life or Health (IDLH)?

Answer: 300 ppm

NIOSH lists the ammonia IDLH at 300 ppm.

Because ammonia vapor is lighter than air, where should a technician expect a vapor cloud from a warm-gas leak to move first?

Answer: It rises toward the ceiling

Ammonia's molecular weight of about 17 makes dry vapor lighter than air, so it rises.

A worker gets liquid ammonia splashed in their eyes. What is the correct first-aid action?

Answer: Flush with clean water for at least 15 minutes

Immediate, prolonged flushing with water for at least 15 minutes is the accepted first aid for ammonia eye exposure.

Under OSHA's Process Safety Management standard (1910.119), what quantity of anhydrous ammonia triggers PSM coverage?

Answer: 10,000 lb

Facilities with more than 10,000 lb of anhydrous ammonia in a process are covered by PSM.

Which metals should NOT be used in ammonia refrigeration piping or components?

Answer: Copper and brass

Ammonia attacks copper and copper alloys such as brass, so steel is used instead.

Approximately what is the flammable range of ammonia in air by volume?

Answer: 16% to 25%

Ammonia is flammable at roughly 16% to 25% by volume in air.