This standard provides a protocol for exposing cable samples to a theoretical 20 kW (70 000 Btu/h) flaming ignition source for a 20-min test duration. The test determines the flame propagation tendency of singleconductor and multi-conductor cables intended for use in cable trays. The purpose of this standard is to establish a test protocol and performance criteria to determine the flame propagation tendency of cables in a vertical cable tray. Revision Standard - Inactive-Reserved. Standardization of cable flame propagation testing is beneficial to cable manufacturers, distributors, and users. Uniform procedures; consistent, repeatable results; and measurable test acceptance criteria are required to allow comparisons among competing products and to allow selection of the correct product for the application.