CARO Emergency Response and Safety 4

Question 1

An operator closes valves on both ends of a liquid ammonia line without a relief path. What hazard is created?

Accepted Answer

Hydrostatic expansion that can rupture the pipe

Answer

Trapped liquid expands as it warms, building enough pressure to rupture piping or valves.

Question 2

Which skin injury is most associated with direct contact with liquid anhydrous ammonia?

Accepted Answer

Frostbite combined with chemical burns

Answer

Liquid ammonia boils at about -28°F and is alkaline, causing both freezing and caustic injuries.

Question 3

What is the approximate odor threshold at which most people can detect ammonia?

Accepted Answer

5 ppm

Answer

Most people detect ammonia's pungent odor at around 5 ppm, well below hazardous levels.

Question 4

Before servicing a compressor, which OSHA standard requires energy sources to be isolated and locked out?

Accepted Answer

29 CFR 1910.147

Answer

The control of hazardous energy (lockout/tagout) standard is 29 CFR 1910.147.

Question 5

After an ammonia exposure victim is removed to fresh air, which first-aid step is appropriate if clothing is contaminated?

Accepted Answer

Remove contaminated clothing and flush skin with water

Answer

Contaminated clothing should be removed and the affected skin flushed with plenty of water.

CARO - Certified Assistant Refrigeration Operator Practice Test