According to regulations, DOT containers must be designed and tested by which organization?

The correct answer is that DOT containers must be designed and tested by the U.S. Department of Transportation. This organization is responsible for regulating and ensuring the safety of various forms of transportation, including hazardous materials like LP gas. The U.S. Department of Transportation sets the standards for how containers are built and tested to ensure they can safely hold and transport propane and other liquefied gases.

The DOT establishes criteria for container design, manufacture, and testing to help prevent leaks, ruptures, and other accidents that could endanger public safety. By adhering to these regulations, manufacturers can ensure that their containers meet stringent safety standards, which is crucial given the flammable nature of LP gas.

The other organizations mentioned, while important in their respective areas, do not set the specific requirements for the design and testing of DOT containers. The National Fire Protection Association focuses more on fire safety codes and standards, the American National Standards Institute develops consensus standards across various industries, and the Occupational Safety and Health Administration (OSHA) mainly deals with workplace safety regulations rather than transportation-specific standards. Therefore, the U.S. Department of Transportation is the authoritative body on these guidelines.