ASTM E1354 is the standard test method for heat and visible smoke release rates for materials and products using an oxygen consumption calorimeter - the cone calorimeter. It is the method US product standards, codes and procurement specifications cite when they want heat release data, and it shares its apparatus and oxygen-consumption principle with ISO 5660.
What E1354 reports
Heat release rate and total heat release, time to ignition, mass loss rate, effective heat of combustion, and smoke obscuration data from the same test. Specimens can be tested horizontally or vertically under the method's provisions, at heat fluxes chosen for the application - the Motis cone calorimeter's cone can be mounted in both orientations, with heat flux from 0 to 100 kW/m².
E1354 or ISO 5660?
The physics is the same; the paperwork differs. Test to the document your specification names: US-facing work usually names E1354, international and European-facing laboratory work usually names ISO 5660. Laboratories serving both markets run one cone calorimeter and hold both method templates in the software. Our cone calorimeter page lists both standards in its configuration, and the blog overview of the cone calorimeter test walks through a test from specimen to report.