Which statement is true about polyvinyl chloride (PVC) in its flexible form?

The statement that polyvinyl chloride (PVC) in its flexible form is commonly referred to as vinyl is accurate. PVC is a widely used plastic polymer that can be produced in both rigid and flexible forms. The flexible variant is often used in a variety of applications due to its versatility, such as in plumbing, electrical cable insulation, flooring, and more. This flexibility comes from the addition of plasticizers that allow the material to be more pliable and easier to work with, leading to the common usage of the term "vinyl" to refer to this type of PVC.

The other statements do not accurately represent the characteristics of flexible PVC. For instance, while some grades of PVC can be used in very specific food-related applications, it is generally not classified as a non-toxic material for food packaging. Additionally, PVC is not biodegradable; rather, it can take a very long time to break down in the environment, contributing to pollution concerns. Furthermore, when burned, PVC can release harmful emissions and toxic fumes, making it important to handle and dispose of it properly to mitigate environmental and health hazards.