What type of approval must all refrigeration recovery cylinders have?

Recovery cylinders must have DOT approval, which stands for the Department of Transportation. This regulation ensures that the cylinders are designed and manufactured to safely contain refrigerants under high pressure, preventing leaks and possible hazards during the recovery process. DOT specifications set the standards for materials, strength, safety features, and testing that ensure these cylinders can withstand the conditions they will encounter in use.

The other options pertain to different types of regulations and standards. For instance, the EPA (Environmental Protection Agency) regulates the handling and disposal of refrigerants but does not specifically issue approvals for recovery cylinder construction. OSHA (Occupational Safety and Health Administration) focuses on workplace safety, while ISO (International Organization for Standardization) develops international quality management standards. While all these organizations play important roles in environmental and workplace safety, it is the DOT that is specifically responsible for the safety standards of recovery cylinders used in refrigeration applications.