Safety and Environmental Practices
Core concepts
Know OSHA and NC safety requirements: PPE, lockout/tagout, fall protection, confined space, and electrical safety. Understand refrigerant handling under EPA Section 608: certification, recovery, recycling, evacuation levels, and prohibitions on venting. Know refrigerant safety classifications (A1, A2L, etc.), flammability concerns with A2L refrigerants, and proper cylinder handling. Understand brazing safety, nitrogen purge to prevent oxidation, and fire prevention. Know environmental rules for mercury thermostats, asbestos, and disposal of oils and filters. Emphasize hazard communication and SDS use.
Traps in questions
- Venting refrigerant is prohibited; recovery is required, and evacuation levels depend on system size and type.
- A2L refrigerants are mildly flammable; they require different handling and leak detection than A1 refrigerants.
- Nitrogen purge during brazing prevents internal oxidation; flowing nitrogen is the standard, not a suggestion.
- Lockout/tagout applies to stored energy, including capacitors and refrigerant pressure.
- Confined space entry requires atmospheric testing and a rescue plan.
Worked example / rule of thumb
EPA evacuation levels: typically 0 psig for small appliances, 10 in. Hg for systems under 200 lbs, and 15 in. Hg for systems of 200 lbs or more (verify against current rules). Always recover, never vent, and document recovery amounts.
Study guidance
Review EPA 608 study materials and OSHA hazard communication requirements; practice a job hazard analysis for a change-out.