NFPA 701 – This National Fire Protection Association standard specifies test methodsfor fire retardant coatings and materials. It includes the NFPA 701 small and large scale flame tests that some flame retardant PVC tarpaulins are evaluated against.

UL94 Flammability Rating – The UL 94 vertical burn test is a common flammability standard for plastics like PVC. Flame retardant PVC tarpaulin manufacturers may pursue a UL 94 V-0 or V-1 rating to demonstrate the flame retardant properties.

State Regulations – Some states have additional requirements for flame retardant ratings or certifications for commercial vehicle covers beyond the federal regulations. Manufacturers must ensure their flame retardant PVC tarpaulins also comply with these laws.

So in summary, the DOT/FMCSR 393.93 regulation establishes the basic requirement that truck tarpaulins must be flame resistant, and then various tests and standards like UL 94, NFPA 701 and others provide potential methods to demonstrate and certify the flame retardancy of PVC truck covers. State regulations may impose additional flame retardant material requirements as well.