CAR Material Selection & Properties 4

Question 1

Capacitors in older appliance motor-start circuits may contain which hazardous substance requiring special handling?

Accepted Answer

Polychlorinated biphenyls (PCBs)

Answer

Older oil-filled capacitors manufactured before 1979 may contain PCB-based dielectric fluid, which is a regulated hazardous waste under TSCA.

Question 2

What is the primary advantage of using HDPE (High-Density Polyethylene) in washer drain hoses over PVC?

Accepted Answer

HDPE does not require plasticizers and is generally considered safer for water contact

Answer

HDPE does not require phthalate plasticizers like flexible PVC does, making it preferable for water-contact applications and simpler to recycle.

Question 3

Which appliance material is classified as 'white goods' scrap and typically commands the lowest per-ton value?

Accepted Answer

Mixed painted steel sheet metal

Answer

Painted or coated mixed steel from appliance bodies is downgraded from clean steel scrap due to coatings and contamination, yielding lower market prices.

Question 4

Porcelain enamel coatings on appliance surfaces are made by fusing which base material onto steel?

Accepted Answer

Inorganic glass frit

Answer

Porcelain enamel is a vitreous (glass-based) coating made from ground glass frit fused to the steel substrate at high temperatures.

Question 5

When recovering refrigerant from a system, the presence of non-condensable gases (NCGs) typically indicates:

Accepted Answer

Air or nitrogen has entered the system, reducing efficiency and complicating recovery

Answer

Non-condensable gases like air or nitrogen in a refrigerant system cause elevated head pressure, reduced cooling efficiency, and must be addressed during recovery.

(CAR) Certified Appliance Recycler Practice Test

(CAR) Certified Appliance Recycler Practice Test

CAR Material Selection & Properties 4