RSES Safety Practices & Regulatory Compliance 5

Question 1

What is the safe oxygen level range for a technician working in a confined space with refrigerant present?

Accepted Answer

19.5% to 23.5%

Answer

OSHA requires atmospheric oxygen concentration in confined spaces to be between 19.5% and 23.5%; below 19.5% is oxygen-deficient and above 23.5% is oxygen-enriched.

Question 2

Under EPA Section 608, refrigerant sales of CFC and HCFC refrigerants in containers larger than 2 lbs are restricted to:

Accepted Answer

Technicians certified under Section 608

Answer

EPA 608 restricts the purchase of CFC and HCFC refrigerants in containers larger than 2 lbs to certified technicians or persons working under their direct supervision.

Question 3

What is the function of a 'fusible plug' on a refrigerant cylinder?

Accepted Answer

It melts at a specific temperature to relieve pressure before cylinder rupture

Answer

A fusible plug is a pressure-relief device filled with a low-melting alloy that melts at elevated temperatures, venting the cylinder before pressure causes catastrophic failure.

Question 4

Which refrigerant class poses the greatest immediate danger of chemical burns and respiratory damage at low concentrations?

Accepted Answer

Natural refrigerants — ammonia (R-717)

Answer

Ammonia (R-717) is immediately dangerous to life and health (IDLH) at 300 ppm and can cause severe burns to eyes, skin, and respiratory tract at relatively low concentrations.

Question 5

A technician discovers a system has been charged with an unknown refrigerant blend. What is the safest course of action?

Accepted Answer

Recover the entire charge without mixing, label the cylinder 'unknown mixture', and have it analyzed

Answer

Unknown blends must be fully recovered into a dedicated cylinder labeled 'unknown mixture' and sent for analysis; mixing refrigerants is prohibited and creates hazardous conditions.

(RSES) Refrigeration Service Engineers Society Certification Practice Test

(RSES) Refrigeration Service Engineers Society Certification Practice Test

RSES Safety Practices & Regulatory Compliance 5