A shop owner hires technicians who recover refrigerant. What certification recordkeeping does the owner need to keep on file?

解析

Employers must maintain records demonstrating that each technician who handles refrigerant holds a valid EPA Section 608 certification, and these records support compliance during inspections. A business license alone or equipment serial numbers do not satisfy this requirement, and the burden is not solely on the technician. Keeping proof of certification on file protects both the technician and the employer.