Which of the following is a key purpose of the regulations found in 49 CFR?

The key purpose of the regulations found in 49 CFR is to promote safety during the transportation of hazardous materials. These regulations are designed to ensure that hazardous materials are packaged, marked, labeled, and handled in a way that minimizes the risk to human health and the environment during transit. By establishing standards for how hazardous materials should be transported, these regulations contribute to a safer transportation system, reducing accidents, environmental contamination, and exposure to harmful substances.

While the other options touch on important aspects related to hazardous materials, they do not capture the primary focus of 49 CFR. Limiting production or restricting the use of chemical substances pertains more to environmental regulations than transportation safety specifically, and guidelines for waste disposal are covered under different sections and regulations that focus on disposal rather than transportation. Thus, the emphasis of 49 CFR remains on maintaining safety throughout the transportation process.