1. Identify a small appliance
It must be fully manufactured, charged, and hermetically sealed at the factory with five pounds or less of refrigerant.
2. Know the recovery options
- Pre-November 15, 1993 equipment: recover 80 percent.
- Newer equipment with operating compressor: recover 90 percent.
- Newer equipment with failed compressor: recover 80 percent.
- Alternative: evacuate to four inches of mercury vacuum.
3. Passive recovery
System-dependent devices rely on appliance components. Run an operating compressor when appropriate. With a failed compressor, use access on both sides and techniques that release refrigerant trapped in oil.
4. Close the service correctly
Temporary solderless access fittings can leak and should be removed after service. Do not treat a piercing valve as a permanent repair.
5. Identify refrigerant before mixing
Use labels, records, and pressure-temperature relationships. Abnormally high stabilized pressure may indicate noncondensables.
6. Heat and chemical safety
Keep refrigerant vapor away from flames and high heat because decomposition products can be toxic and irritating.
Source basis: EPA Section 608 Test Topics and 40 CFR Part 82, Subpart F. Review the official sources before the real exam because regulatory details can change.